Improvement of chemo- and stereoselectivity for phosphorothioate oligonucleotides in capillary electrophoresis by addition of cyclodextrins.

Phosphorothioate (PS) modification is one of the most widely used oligonucleotide chemical alterations in the oligonucleotide backbone. It has proven to be crucial in the field of therapeutic oligonucleotides regarding the optimization of their physicochemical and biological properties. In this study, a capillary electrophoresis (CE) method with an acidic background electrolyte (BGE) containing a combination of ß- and γ-cyclodextrins derivatives as chiral selectors is proposed for the diastereomeric separation of 5-mer oligonucleotides containing 0, 1, 2, or 3 phosphorothioate linkages (5´-TCGTG-3´). The effects of the BGE pH, organic modifier addition, and type of cyclodextrin (CD) on chemo- and stereoselectivity and resolution were studied. A mixture of 25 mM (2-hydroxy-3-N,N,N-trimethylamino)propyl-γ-CD and 10 mM carboxymethyl-ß-cyclodextrin in a pH 3 buffer was found to be the most appropriate system for the qualitative evaluation of the short oligonucleotides investigated. These phosphorothioate oligonucleotides were separated with high efficiency in less than 11 min with no capillary treatment. The suggested approach can be the basis for purity testing of this new generation of therapeutics.

Outcomes in Severe Upper GI Hemorrhage from Dieulafoy's Lesion with Monitoring of Arterial Blood Flow.

BACKGROUND: Dieulafoy's lesion (DL) is a rare but increasingly recognized cause of severe upper GI hemorrhage (SUGIH). There is little consensus regarding the endoscopic approach to management of bleeding from DL. AIMS: Our purposes were to compare 30-day outcomes of patients with SUGIH from DL with Doppler endoscopic probe (DEP) monitoring of blood flow and guided treatment versus standard visually guided hemostasis (VG). METHODS: Eighty-two consecutive DL patients with SUGIH were identified in a large CURE Hemostasis database from previous prospective cohort studies and two recent RCTs at two university-based medical centers. 30-day outcomes including rebleeding, surgery, angiography, death, and severe medical complications were compared between the two treatment groups. RESULTS: 40.2% of DL bleeds occurred in inpatients. 43.9% of patients had cardiovascular disease, and 48.7% were taking medications associated with bleeding. For the entire cohort, 41.3% (26/63) of patients treated with VG had a composite 30-day outcome as compared to 10.5% (2/19) of patients treated with DEP (p = 0.017). Rebleeding occurred within 30 days in 33.3% and 10.5% of those treated with VG and DEP, respectively (p = 0.051). After propensity score matching, the adjusted 30-day composite outcome occurred in 39.0% in the VG group compared to 2.6% in the DEP group (p < 0.001). Adjusted 30-day rebleeding occurred in 25.3% in the VG group versus 2.6% in the DEP group (p < 0.001). DISCUSSION: DL patients with SUGIH were frequently inpatients and had severe cardiovascular comorbidities and recurrent bleeding. Lesion arterial blood flow monitoring and obliteration are an effective way to treat bleeding from DL which reduces negative 30-day clinical outcomes.

Molecular epidemiology of Escherichia coli sequence type 131 and its H30/H30-Rx subclones recovered from extra-intestinal infections: first report of OXA-48 producing ST131 clone from Iran.

Multidrug-resistant (MDR) O25b-ST131 clone of Escherichia coli is well established as a significant cause of extra-intestinal infections worldwide. However, there have been no studies about the prevalence of ST131 and its H30/H30Rx subclones from Iran. The prevalence of ST131 was 29.8% among phylogroups B2, D, and F of E.coli isolates recovered from extra-intestinal infections. Fifty-seven (90.4%) and six (9.6%) of isolates belonged to serogroups O25b and O16 respectively, and exhibited high rates of MDR (98.4% and 83.3%) and extended spectrum ß-lactamase (ESBL) production (96.8% and 83.3%). The majority (56/57, 98.2%) of O25b isolates belonged to H30 lineage; of those, 24 isolates (42.8%) belonged to H30-Rx subclone. O16-ST131 isolates were H30-negative. The resistance rate values of O16-ST131subgroup were lower for fluoroquinolones/aminoglycosides and higher for carbapenems, cephalosporins, ß-lactam/ß-lactamase inhibitors and trimethoprim/sulfamethoxazole, as compared to O25b-ST131 isolates. Among H30 sub lineage and in comparison with non-Rx isolates, H30-Rx subclone showed higher resistance score and virulence genes (papA and papC), and was also associated with CTX-M group 1. bla OXA-48 carbapenemase was detected in seven O25b and one O16 isolates; of those, one O25b-ST131 isolate was carbapenem-susceptible. The ST131 isolates comprised 15 'enterobacterial repetitive intergenic consensus' (ERIC) clusters, and O16 isolates remained distributed in five groups in cluster with O25b-ST131 isolates. In conclusion, this is the first report of the presence of MDR, bla OXA-48/CTX-M-positive O25b/O16-ST131 isolates in Iran. Contrary to lower prevalence of O16-ST131 subgroup, higher resistance rates to ß-lactam antibiotics may indicate the importance of this subgroup in the spread of MDR E.coli isolates.

Severe upper gastrointestinal hemorrhage from linear gastric ulcers in large hiatal hernias: a large prospective case series of Cameron ulcers.

We report a case series of all consecutive patients hospitalized in our two tertiary referral medical centers over the past 17 years for Cameron ulcers causing severe upper gastrointestinal hemorrhage (GIH) or severe obscure GIH. Cameron ulcers were diagnosed in 25 of the 3960 screened patients with severe upper GIH or severe obscure GIH (0.6 %). Of these, 21 patients had a prospective follow-up (median time 20.4 months [interquartile range: 8.5 - 31.8]). Patients were more often elderly women with chronic anemia, always had large hiatal hernias, and were usually referred for obscure GIH. Twelve of the 21 patients (57 %) were referred for surgery while being treated with high-dose proton pump inhibitors (PPIs). The other 9 patients (43 %) continued PPIs without any rebleeding during the follow-up. Cameron ulcers in large hiatal hernias are an uncommon cause of severe upper GIH. The choice of medical vs. surgical therapy should be individualized.