Helicobacter Pylori Infection in Pediatric Patients Living in Europe: Results of the EuroPedHP Registry 2013 to 2016

Objectives: The aim of the study was to assess clinical presentation, endoscopic findings, antibiotic susceptibility and treatment success of Helicobacter pylori (H. pylori) infected pediatric patients. Methods: Between 2013 and 2016, 23 pediatric hospitals from 17 countries prospectively submitted data on consecutive H. pylori-infected (culture positive) patients to the EuroPedHP-Registry. Results: Of 1333 patients recruited (55.1% girls, median age 12.6 years), 1168 (87.6%) were therapy naïve (group A) and 165 (12.4%) had failed treatment (group B). Patients resided in North/Western (29.6%), Southern (34.1%) and Eastern Europe (23.0%), or Israel/Turkey (13.4%). Main indications for endoscopy were abdominal pain or dyspepsia (81.2%, 1078/1328). Antral nodularity was reported in 77.8% (1031/1326) of patients, gastric or duodenal ulcers and erosions in 5.1% and 12.8%, respectively. Primary resistance to clarithromycin (CLA) and metronidazole (MET) occurred in 25% and 21%, respectively, and increased after failed therapy. Bacterial strains were fully susceptible in 60.5% of group A, but in only 27.4% of group B. Primary CLA resistance was higher in Southern and Eastern Europe (adjusted odds ratio [ORadj] = 3.44, 95% confidence interval [CI] 2.22-5.32, P < 0.001 and 2.62, 95% CI: 1.63-4.22, P < 0.001, respectively) compared with Northern/Western Europe. Children born outside Europe showed higher primary MET resistance (ORadj = 3.81, 95% CI: 2.25-6.45, P < 0.001). Treatment success in group A reached only 79.8% (568/712) with 7 to 14 days triple therapy tailored to antibiotic susceptibility. Conclusions: Peptic ulcers are rare in dyspeptic H. pylori-infected children. Primary resistance to CLA and MET is markedly dependent on geographical regions of birth and residence. The ongoing survey will show whether implementation of the updated ESPGHAN/NASPGHAN guidelines will improve the eradication success.info:eu-repo/semantics/publishedVersio

Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17), under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO) calculations

Mechanistic Insights into Ring-Opening and Decarboxylation of 2-Pyrones in Liquid Water and Tetrahydrofuran

2-Pyrones, such as triacetic acid lactone, are a promising class of biorenewable platform chemicals that provide access to an array of chemical products and intermediates. We illustrate through the combination of results from experimental studies and first-principle density functional theory calculations that key structural features dictate the mechanisms underlying ring-opening and decarboxylation of 2-pyrones, including the degree of ring saturation, the presence of C═C bonds at the C4═C5 or C5═C6 positions within the ring, as well as the presence of a β-keto group at the C4 position. Our results demonstrate that 2-pyrones undergo a range of reactions unique to their structure, such as retro-Diels–Alder reactions and nucleophilic addition of water. In addition, the reactivity of 2-pyrones and the final products formed is shown to depend on the solvent used and the acidity of the reaction environment. The mechanistic insights obtained here provide guidance for the selective conversion of 2-pyrones to targeted chemicals.Reprinted (adapted) with permission from Journal of American Chemical Society, 135(15); 5699-5708. Doi: 10.1021/ja312075r. Copyright 2013 American Chemical Society. </p

Matrix isolation EPR study of novel radical cations from bicyclic[3.2.0] and monocyclic C7H8 and C7H10 compounds

The radical cations of bicyclo[3.2.0]hepta-2,6-diene and bicyclo[3.2.0]hept-2-ene have been obtained by γ-irradiation of the parent compounds in Freon matrices and their structures investigated by EPR spectroscopy and MNDO and INDO calculations. In a CFCl3 matrix, ring opening to the isomeric cycloheptatriene and cycloheptadiene radical cations occurred, whereas in a CF2ClCFCl2 matrix the prevalent reaction was deprotonation to the neutral bicyclo[3.2.0]hepta-2,6-dien-4-yl and bicyclo[3.2.0]hept-2-en-4-yl radicals, respectively

ESR Study of radical cations from γ-irradiation of bicyclo[3.1.0]hex-2-ene in freon matrices

Bicyclo[3.1.0]hex-2-ene radicalcation, generated by γ-irradiation of the parent compound in freon matrices at 77 K, undergoes ring opening to the 1,3-cyclohexadiene radicalcation. In CF2ClCFCl2 matrix both radicalcations also undergo deprotonation to the corresponding neutral radicals

PIAS Proteins as Repressors of Oct4 Function

The POU domain transcription factor Oct4 plays essential functions in the maintenance of pluripotent embryonic and germ cells of mammals. Molecular mechanisms of Oct4 action remain poorly understood. To isolate modulators of Oct4 activity, we performed a yeast two-hybrid screen with the Oct4 POU domain as a bait and isolated PIASy as an Oct4-interacting protein. Oct4 and PIASy interact in vivo via their POU domain and SAP-domain-containing N terminus, respectively. PIASy does not enhance Oct4 sumoylation but acts as a potent inhibitor of Oct4-mediated transcriptional activation, sequestering Oct4 protein from the vicinity of Cajal bodies and splicing speckles to the nuclear periphery. These modes of PIASy action are uncoupled from its sumoylation activity. Other PIAS family members, PIAS1 and PIAS3, can also interact with Oct4 in vivo and target Oct4 to the nuclear periphery, depending on cellular context. We propose that Oct4 inhibition, mediated by this new class of transcriptional partners, might be instrumental during mammalian development

Cooperative proton-electron transfer in a supramolecular structure of meso-1,2-bis-(4-dimethylaminophenyl)-1,2-ethanediol and bis(4-cyanobenzylidene)ethylenediamine

A supramolecular 1:1 complex of the title compounds undergoes light-induced cooperative proton-electron transfer which can be switched back by warming to 60°C. The complex (see Figure) is found to exhibit a unique from the photochromism, meaning that it could have potential in optical switching (with termal back switching) or optical data storage applications