Detection of primary clarithromycin resistance of Helicobacter pylori and association between cagA + status and clinical outcome

Helicobacter pylori was examined in 110 patients (82 (74.5) with gastritis, 18 (16.4) with duodenitis, six (5.5) with duodenal ulcer and gastroesophageal reflux, and four (3.6 %) with normal) with gastrointestinal problems living in rural area, no history of macrolide use, and detected by culture (71.8) or direct detection from gastric biopsies by PCR (82.7 %). Also, cagA gene was identified using PCR and was found positive in 68/91 (74.7 %) strains. The prevalence of clarithromycin-resistant H. pylori was investigated by two methods including PCR–RFLP (7.7 (A2142G 1.1 and A2143G 6.6 %)) and twofold agar dilution (8.9 %) to detect phenotypic and genotypic status simultaneously. Among all the H. pylori positive patients, eight (8.8 %) isolates were found to be resistant to clarithromycin by at least one of the AD and/or PCR–RFLP methods. H. pylori positive rates were significantly correlated with patients' sex, age, and endoscopic findings (p?=?0.040, <0.001 and <0.001, respectively). There were no differences in gender or endoscopic findings related to cagA ⁺ and cagA ^? patients. The gene of cagA was not significantly helpful in predicting the clinical outcome of H. pylori infection alone. In conclusion, we revealed that there was a low prevalence of primer clarithromycin resistance in patients living in rural area with no history of macrolide use. The prevalence of mutant strains among the macrolide-resistant H. pylori varies even geographically between close provinces.     

Cardioprotective effect of selenium via modulation of cardiac ryanodine receptor calcium release channels in diabetic rat cardiomyocytes through thioredoxin system

Increased oxidative stress contributes to heart dysfunction via impaired Ca²⁺ homeostasis in diabetes. Abnormal RyR2 function related with altered cellular redox state is an important factor in the pathogenesis of diabetic cardiomyopathy, while its underlying mechanisms remain poorly understood. In the present study, we used a streptozotocin-induced rat model of diabetic cardiomyopathy and tested a hypothesis that diabetes-related alteration in RyR2 function is related with ROS-induced posttranslational modifications. For this, we used heart preparations from either a diabetic rat or a sodium selenate (NaSe)-treated (0.3 mg/kg for 4 weeks) diabetic rat as well as either NaSe- (100 nmol/L) or thioredoxin (Trx; 5 μmol/L)-incubated (30 min) diabetic cardiomyocytes. Experimental approaches included imaging of intracellular free-Ca²⁺ ([Ca²⁺]_i) under both electrically stimulated and resting Fluo-3-loaded cardiomyocytes. RyR2-mediated SR-Ca²⁺ leak was significantly enhanced in diabetic cardiomyocytes, resulting in reduced amplitude and prolonged time courses of [Ca²⁺]_i transients compared to those of controls. Both SR-Ca²⁺ leak and [Ca²⁺]_i transients were normalized by treating diabetic rats with NaSe or by incubating diabetic myocytes with NaSe or Trx. Moreover, exposure of diabetic cardiomyocytes to antioxidants significantly improved [Ca²⁺]_i handling factors such as phosphorylation/protein levels of RyR2, amount of RyR2-bound FKBP12.6 and activities of both protein kinase A and CaMKII. NaSe treatment also normalized the oxidative stress/antioxidant defense biomarkers in plasma as well as Trx activity and nuclear factor-κB phosphorylation in the diabetic rat heart. Collectively, these findings suggest that redox modification through Trx-system besides the glutathione system contributes to abnormal function of RyR2s in hyperglycemic cardiomyocytes, presenting a potential therapeutic target for treating diabetics to preserve cardiac function.     

Apical myosin XI anticipates F‐actin during polarized growth of Physcomitrella patens cells

Tip growth is essential for land colonization by bryophytes, plant sexual reproduction and water and nutrient uptake. Because this specialized form of polarized cell growth requires both a dynamic actin cytoskeleton and active secretion, it has been proposed that the F‐actin‐associated motor myosin XI is essential for this process. Nevertheless, a spatial and temporal relationship between myosin XI and F‐actin during tip growth is not known in any plant cell. Here, we use the highly polarized cells of the moss Physcomitrella patens to show that myosin XI and F‐actin localize, in vivo, at the same apical domain and that both signals fluctuate. Surprisingly, phase analysis shows that increase in myosin XI anticipates that of F‐actin; in contrast, myosin XI levels at the tip fluctuate in identical phase with a vesicle marker. Pharmacological analysis using a low concentration of the actin polymerization inhibitor latrunculin B showed that the F‐actin at the tip can be significantly diminished while myosin XI remains elevated in this region, suggesting that a mechanism exists to cluster myosin XI‐associated structures at the cell's apex. In addition, this approach uncovered a mechanism for actin polymerization‐dependent motility in the moss cytoplasm, where myosin XI‐associated structures seem to anticipate and organize the actin polymerization machinery. From our results, we inferred a model where the interaction between myosin XI‐associated vesicular structures and F‐actin polymerization‐driven motility function at the cell's apex to maintain polarized cell growth. We hypothesize this is a general mechanism for the participation of myosin XI and F‐actin in tip growing cells.     

WAPL-Mediated Removal of Cohesin Protects against Segregation Errors and Aneuploidy

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Tetraspanin CD9 links junctional adhesion molecule-A to αvβ3 integrin to mediate basic fibroblast growth factor–specific angiogenic signaling

Junctional adhesion molecule-A (JAM-A) is a member of the immunoglobulin family with diverse functions in epithelial cells, including cell migration, cell contact maturation, and tight junction formation. In endothelial cells, JAM-A has been implicated in basic fibroblast growth factor (bFGF)-regulated angiogenesis through incompletely understood mechanisms. In this paper, we identify tetraspanin CD9 as novel binding partner for JAM-A in endothelial cells. CD9 acts as scaffold and assembles a ternary JAM-A-CD9-αvβ3 integrin complex from which JAM-A is released upon bFGF stimulation. CD9 interacts predominantly with monomeric JAM-A, which suggests that bFGF induces signaling by triggering JAM-A dimerization. Among the two vitronectin receptors, αvβ3 and αvβ5 integrin, which have been shown to cooperate during angiogenic signaling with bFGF and vascular endothelial growth factor (VEGF), respectively, CD9 links JAM-A specifically to αvβ3 integrin. In line with this, knockdown of CD9 blocks bFGF- but not VEGF-induced ERK1/2 activation. JAM-A or CD9 knockdown impairs endothelial cell migration and tube formation. Our findings indicate that CD9 incorporates monomeric JAM-A into a complex with αvβ3 integrin, which responds to bFGF stimulation by JAM-A release to regulate mitogen-activated protein kinase (MAPK) activation, endothelial cell migration, and angiogenesis. The data also provide new mechanistic insights into the cooperativity between bFGF and αvβ3 integrin during angiogenic signaling.     

Prognostic value of rising mean platelet volume during hospitalization in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Background

The prognostic significance of changes in mean platelet volume (MPV) during hospitalization in ST segment elevation myocardial infarction (STEMI) patients underwent primary percutaneous coronary intervention (pPCI) has not been previously evaluated. The aim of this study was to determine the association of in-hospital changes in MPV and mortality in these patients.

Methods

Four hundred eighty consecutive STEMI patients were enrolled in this retrospective study. The patients were grouped as survivors (n?=?370) or non-survivors (n?=?110). MPV at admission, and at 48–72?h was evaluated. Change in MPV (MPV at 48–72?h minus MPV on admission) was defined as ΔMPV.

Results

At follow-up, long-term mortality was 23%. The non-survivors had a high ΔMPV than survivors (0.37 (??0.1–0.89) vs 0.79 (0.30–1.40) fL, p?<? 0.001). A high ΔMPV was an independent predictor of all cause mortality ((HR: 1.301 [1.070–1.582], p?=?0.008). Morever, for long-term mortality, the AUC of a multivariable model that included age, LVEF, Killip class, and history of stroke/TIA was 0.781 (95% CI:0.731–0.832, p?<? 0.001). When ΔMPV was added to a multivariable model, the AUC was 0.800 (95% CI: 0.750–0.848, z?=?2.256, difference p?=?0.0241, Fig. 1). Also, the addition of ΔMPV to a multivariable model was associated with a significant net reclassification improvement estimated at 24.5% (p?=?0.027) and an integrated discrimination improvement of 0.014 (p?=?0.0198).

Conclusions

Rising MPV during hospitalization in STEMI patients treated with pPCI was associated with long-term mortality.

     

Enantioselective recognition of carboxylic acids by novel fluorescent triazine‐based thiazoles

Hydrogen bonding and π‐π interactions take special part in the enantioselectivity task. In this regard, because of having both hydrogen acceptor and hydrogen donor groups, melamine derivatives become more of an issue for enantioselectivity. In the light of such information, triazine‐based chiral, fluorescence active novel thiazole derivatives L1 and L2 were designed and synthesized from (S)‐(?)‐2‐amino‐1‐butanol and (1S,2R)‐(+)‐2‐amino‐1,2‐diphenylethanol. The structural establishment of these compounds was made by spectroscopic methods such as FTIR, ¹H, and ¹³C NMR. While the solution of these compounds in DMSO did not show any fluorescence emission, it was observed that the emission increased 44‐fold for L1 and 55‐fold for L2 in 95% water, similar to the aggregation‐induced emission (AIE) characterized compounds. In this regard, enantioselective capabilities of these compounds against carboxylic acids were tested, and in experiments carried out at a ratio of 40/60 DMSO/H₂O, it was determined that R‐2ClMA increased the fluorescence emission of L1 chiral receptor by 2.59 times compared to S‐isomer.     

Protective effect of ginkgo biloba against gossypol-induced apoptosis in human lymphocytes

Ginkgo biloba (EGb 761) is a well-defined plant extract that directly scavenges hydroxyl radicals. It is a potent antioxidant that inhibits apoptosis in cultured cells and is effective in treating mild-to-moderate dementia in Alzheimer patients. Apoptosis is an active process of cell destruction and it plays an important role in pathological processes. The aim of this study is to investigate the anti-apoptotic effect of EGb 761 in gossypol-treated human lymphocytes. Pretreatment of lymphocytes with 10 microg/ml EGb 761 for 30 min or 1h decreased the percentage of apoptosis to 17.5% and 20%, respectively. EGb 761 treatment (25-150 microg/ml) decreased the level of apoptosis to a plateau between 8 and 10% of the control values. We conclude that EGb 761 reduces gossypol-induced apoptosis in human lymphocytes.