OAc Groups Research Articles

Lower dose direct oral anticoagulation or warfarin in atrial fibrillation. Which one is the best when time on therapeutic range information is available?

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Helsinki and Uusimaa Hospital District (TYH2019309) and The Finnish Foundation for Cardiovascular Research Background and aims Elderly patients with atrial fibrillation (AF) and patients with renal failure – for example – are recommended to use reduced doses of direct oral anticoagulants (DOACs) to minimize risk of ischemic stroke and hemorrhagic complications. However, it is not known whether DOACs used with reduced doses are better than warfarin when the quality of warfarin treatment is available by means of time in therapeutic range (TTR). Methods The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) is a nationwide study of AF patients that combines data from several Finnish health care registers. Here all new-onset AF patients from 2011 to 2018 on reduced dose DOAC in Finland and patients on warfarin with TTR data were analyzed. Comorbidities, concomitant medications and CHA2DS2-VASc -scores were recorded until date of AF diagnosis. OAC purchases from diagnosis of AF to the end of study were analyzed. ICD-10 diagnoses for stroke (ischemic or hemorrhagic) or transient ischemic attack during OAC-use were analyzed until maximum follow-up of 730 days. Crude rates of stroke as well as weighted rates are provided. To avoid confounding by baseline characteristics as well as medications, an inverse probability of treatment weighted analysis was made. For warfarin users with sufficient laboratory data, time in therapeutic range (TTR) was calculated and patient quartiles by TTR were assigned. Results Altogether, 52 204 new-onset AF patients with OAC therapy (46.1 % male, mean age 75.7 years, 43 549 on warfarin - with mean TTR 66%, median TTR 72%) were followed for 91 549 patient-years (py). Rate of stroke among patients on lower dose DOACs was 5.2/100 patient years (py) for dabigatran (n=2 672), 4.3/100 py for apixaban (n=3 936), 3.9 /100 py for rivaroxaban (n=1 866). In the TTR-quartiles of patients on warfarin, the rates of stroke were 9.3, 7.2, 5.5 and 4.3 /100 py from the lowest (mean TTR 32%) to the highest quartile (mean TTR 90%), respectively. The weighted rates of stroke were 5.1, 3.5 and 3.1/100 py for dabigatran, apixaban and rivaroxaban, respectively and for warfarin from the lowest to the highest quartile: 8.7, 7.0, 5.4 and 4.1/100 py. Figure provides survival probabilities of the OAC groups with confidence limits. Conclusion In AF patients treated with OAC, the rates of stroke were highest among patients on warfarin at the lowest TTR quartiles, while the differences between high TTR groups and lower dose DOACs were only modest.

How good is time-in-therapeutic-range defined warfarin treatment compared to standard dose direct oral anticoagulants? Incidence of stroke in atrial fibrillation in a nationwide registry study

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): The Finnish Foundation for Cardiovascular Research, and Helsinki and Uusimaa Hospital District research fund. Background and aims Direct oral anticoagulants (DOACs) have largely replaced warfarin in patients with atrial fibrillation (AF) to reduce risk of stroke. However, it is not known whether DOACs are more efficacious in preventing stroke or safer than good-quality warfarin treatment with high time in therapeutic range (TTR). Methods The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) is a nationwide study of AF patients that combines data from several Finnish health care registers. We analyzed all new-onset AF patients in Finland from January 2011 to December 2018 with laboratory data available. Comorbidities, concomitant medications and CHA2DS2-VASc -scores were recorded until date of AF diagnosis. OAC purchases from diagnosis of AF to the end of study were analyzed. ICD-10 diagnoses for stroke (ischemic or hemorrhagic) or transient ischemic attack during OAC use were analyzed until maximum follow-up of 730 days. Confounding factors by baseline characteristics as well as medications were taken in account by use of an inverse probability of treatment weighted analysis. For warfarin users, time in therapeutic range (TTR) was calculated and patient quartiles by TTR were assigned. Rate of stroke in different TTR quartiles for warfarin users were compared to standard dose dabigatran (150 mg bd.), apixaban (5mg bd.) and rivaroxaban (20mg od.). Results Altogether, 74 008 new-onset AF patients with OAC therapy (50.4 % male, mean age 73.0 years, 43 549 on warfarin, with mean TTR 66% and median TTR 72%) were followed for 109 143 patient years (py). Rate of stroke among patients with standard dose direct oral anticoagulants was 6.0/100 py for dabigatran (n=4545), 6.2/100 py for apixaban (n=12 426) and 4.0/100 py for rivaroxaban (n=12 950). In the TTR quartiles of patients on warfarin, rates of stroke were 9.3, 7.2, 5.5 and 4.3/100 py from the lowest (mean TTR 32%) to the highest quartile (mean TTR 90%), respectively. The weighted rates of stroke were 6.3, 6.1 and 4.5/100 py for dabigatran, apixaban and rivaroxaban, respectively, and for warfarin from the lowest to the highest quartile: 8.8, 7.0, 5.5 and 4.2/100 py, respectively. The Figure provides survival probabilities (crude rates) of stroke with confidence intervals of the analysed OAC groups. Conclusion Rates of stroke were evidently the highest among patients on warfarin in the two lowest TTR quartiles, while the differences between high TTR groups and standard dose DOACs were only modest.

Choice of antithrombotic therapy for patients with atrial fibrillation undergoing carotid angioplasty and stenting: a nationwide population-based study

Nonvalvular atrial fibrillation (NVAF) and carotid stenosis are important risk factors for stroke. Carotid angioplasty and stent placement (CAS) is recommended for patients with symptomatic high-grade carotid stenosis. The optimal medical management for patients with NVAF after CAS remains unclear. We aimed to clarify this issue using real-world data from the Taiwanese National Health Insurance Research Database (NHIRD). In total, 2116 consecutive NVAF patients who received CAS between January 1, 2010, and December 31, 2016, from NHIRD were divided into groups based on post-procedure medication as follows: only antiplatelet agent (OAP, n = 587); only anticoagulation agent (OAC, n = 477); dual antiplatelet agents (DAP, n = 49); and a combination of antiplatelet and anticoagulation agents (CAPAC, n = 304). Mortality, vascular events, and major bleeding episodes were compared after matching with the Charlson comorbidity index and CHA2DS2-VASc score. The CAPAC and the OAC groups had lower mortality rates than the OAP group (P = 0.0219), with no statistical differences in major bleeding, ischemic stroke, or vascular events. Conclusively, OAC therapy after CAS appears suitable for NVAF patients. CAPAC therapy might be considered as initial therapy or when there is concern about vascular events.

Performance Advantages of Left-Handed Cricket Batting Talent.

The purpose of this study was to examine performance advantages associated with batting stance, in the form of left- vs. right-handed dominant stance, and orthodox vs. reverse stance, of talented junior cricket batters within age-restricted competitions. Data were sourced from the national male younger age competition (YAC; Under-17; n = 237) and older age competition (OAC; Under-19; n = 302), as well as female YAC (Under-15; n = 234) and OAC (Under-18; n = 260) over a 4-year period. Left-hand dominant (LHD) batters were consistently overrepresented in the male YAC (Right: 69.2%; Left: 30.8%) and OAC (Right: 68.2%; Left: 31.8%) compared with the expected general population distribution. Male LHD batters exhibited a significantly (p < 0.05) higher batting aggregate (YAC: 116.82 ± 84.75 vs. 137.84 ± 89.74; OAC: 117.07 ± 89.00 vs. 146.28 ± 95.99), scored more runs (YAC: 19.65 ± 12.32 vs. 23.96 ± 14.71; OAC: 19.27 ± 12.61 vs. 23.98 ± 14.15), spent more time batting (YAC: 45.33 ± 25.89 min vs. 54.59 ± 28.62 min; OAC: 39.80 ± 21.79 min vs. 49.33 ± 27.41 min), and scored more boundary-4s per game (YAC: 1.83 ± 1.40 vs. 2.44 ± 1.87; OAC: 1.76 ± 1.32 vs. 2.19 ± 1.83), across both YAC and OAC groups with small effect sizes. No overrepresentation was present for either female group (YAC, Right: 88.5%/Left: 11.5%; OAC, Right: 90.0%/Left: 10.0%). Female LHD batters exhibited significantly higher batting aggregate (68.97 ± 53.17 vs. 102.96 ± 73.48), batting average (13.24 ± 10.88 vs. 17.75 ± 12.28), and spent more time batting per game (25.52 ± 15.08 vs. 37.75 ± 26.76 min), but only at the OAC level with small-moderate effects sizes. Finally, there were few performance advantages identified to batting with a reverse stance, with further work needed to clarify any potential biomechanical benefits. Team selection practices may exploit the left-handed advantage by over-selecting talented left-handed junior cricketers. Practical implications for coaches include creating practice environments that negate the negative frequency-dependent selection, such as providing more practice opportunities for their players against left-handed opponents.

Apixaban role in the treatment of venous thromboembolic complications in patients with active cancer

The relationship of venous thromboembolic complications (VTEC) to cancer is well known. Modern recommendations for the treatment of VTEC in patients with cancer suggest treatment with subcutaneous injections of LMWH in the first 6 months. The emergence of evidence of comparable efficacy and safety of four OACs (dabigatran, rivaroxaban, apixaban and edoxaban) with traditional LMWH treatment and further transition to VKA led to their approval for VTEC treatment. But the efficacy and safety of OACs compared to long-term LMWH treatment in VTEC and cancer patients until recently was limited to single randomized studies (Hokusai VTE Cancer and SELECT-D), in which edoxaban and rivaroxaban were compared to dalteparin. The results were close: the recurrence rate of vTEC in oAC groups was lower than in those receiving dalteparin, but the number of bleedings was higher, mainly due to gastrointestinal bleeding. In March 2020, the results of a prospective randomized open Caravaggio study were published to demonstrate that the results of prescription of oral apixaban in order to prevent relapse of vTEC in patients with cancer-associated vTEC will not be worse than those of subcutaneous LMWH injections, and will not cause an increase in major bleedings. the study results showed that relapses of VTEC in the apixaban group were 5.6% and in the dalteparin group 7.9% (RA 0.63; 95% CI [0.371.07]; P < 0.001 for «not worse»; P = 0.09 for «better»). Heavy bleeding was observed in 3.8% of cases in the apixaban group and in 4.0% of patients receiving dalteparin (RA 0.82; 95% CI [0.40-1.69]; P = 0.60). Large gastrointestinal bleedings during treatment were recorded in 11 patients (1,9%) in the apixaban group and in 10 patients (1,7%) receiving dalteparin. oral apixaban proved to be no worse than subcutaneous dalteparin injections in the treatment of VTEC in cancer patients. Unlike studies with rivaroxaban and edoxaban, there was no increase in risk of large bleeding, including from the gastrointestinal tract, in patients receiving apixaban.

Prothrombotic Responses After Catheter Ablation for Atrial Fibrillation During Uninterrupted Oral Anticoagulant AgentAdministration.

The aim of this study was to evaluate the extent of changes in prothrombotic responses after catheter ablation for atrial fibrillation (AF) under uninterrupted oral anticoagulant agent (OAC) administration. Catheter ablation for AF has a potential risk for prothrombotic activation and silent thromboembolic events. A total of 814 patients (n=172 [warfarin], n=153 [dabigatran], n=134 [rivaroxaban], and n=301 [apixaban] patients undergoing AF ablation and a control group of 54 patients undergoing non-AF ablation) were included. Uninterrupted OACs were administered during the procedure in patients with AF. Blood samples were collected the day before and 3days after the procedure. At baseline, D-dimer levels were within normal limits (≤1.0μg/ml) in more than 90% of the patients in all groups. However, after 3days, this proportion decreased to 67%, 73%, 59%, 68%, and 65% in the warfarin, dabigatran, rivaroxaban, apixaban, and control groups, respectively (p=0.180). Changes in prothrombin fragment 1+2 levels differed (p<0.001), whereas fibrin monomer complex levels 3days after ablation at a trough were equivalent within normal ranges among the groups (p=0.146). Multivariate analysis revealed that age, CHA2DS2-VASc score, first session, and radiofrequency ablation were independent predictors of increased D-dimer levels after the procedure. Various changes in prothrombotic markers were observed between the warfarin and direct OAC groups after propensity score matching analyses. The coagulation cascade was activated after catheter ablation for AF under uninterrupted OAC administration. The changes in various prothrombotic markers differed among the OAC groups.

Outcomes of Micra leadless pacemaker implantation with uninterrupted anticoagulation.

Implantation of the MICRA Leadless pacemaker requires the use of a 27 French introducer, blunt delivery system and device fixation to the myocardium via nitinol tines. While prior studies have proven its safety, it is unclear whether performing this procedure with uninterrupted anticoagulation exposes patients to increased risks. We sought to investigate the feasibility and safety of continuing therapeutic anticoagulation during the periprocedural period. We evaluated all patients undergoing MICRA placement at our institution between April 2014 and August 2018 with complete follow-up data (n = 170). Patients were stratified into two groups: those on active anticoagulation (OAC, n = 26), defined as having an International normalized ratio >2.0 or having continued a direct oral anticoagulant, and those not anticoagulated (Off-OAC, n = 144). We evaluated for a composite outcome of all major complications, including access site complications and pericardial effusion. OAC and Off-OAC groups had similar mean age (74 ± 13 vs 75 ± 13 years; P = .914). The OAC group had a nonsignificantly lower prevalence of end-stage renal disease (8% vs 17%; P = .375) and aspirin use (27% vs 47%; P = .131). Those in the OAC group were more likely to be on warfarin than those in the Off-OAC group (81% vs 30%; P < .001). The rate of the composite endpoint was similar between the OAC and Off-OAC groups (3.8 % vs 1.4%, respectively; P = .761). Length of stay was similar between groups (1.3 ± 2.6 vs 2.3 ± 3.4 days; P = 0.108). Continuation of therapeutic anticoagulation during MICRA implantation appears to be feasible, safe and associated with shorter hospitalization among appropriately selected individuals.

A deprotection procedure using SO3H silica gel to remove non-silyl protecting groups

Protecting groups are indispensable in organic synthesis and there is a great need for a variety of deprotection methods. Here, we investigated the scope of the application of a deprotection procedure using SO3H silica gel, which we have previously reported as a desilylation procedure. Under these conditions, -OMOM, -OSEM, -OTHP, and -OAc groups and dimethyl acetal were cleaved. Pivaloyloxy, benzyloxy and methoxy carbonyl groups remained intact and selective deprotection of TBS groups in the presence of other protecting groups was accomplished. We succeeded in cleaving an acetyl group on a secondary alcohol in a highly polar nortropine derivative. Our findings here provide another deprotection option and would be helpful in the synthesis of multifunctional compounds.

Efficient Synthesis of α‐Glycosyl Chlorides Using 2‐Chloro‐1,3‐dimethylimidazolinium Chloride: A Convenient Protocol for Quick One‐Pot Glycosylation

A mild and convenient method for the synthesis of α‐glycosyl chlorides in high 80–96 % yields within 15–30 min using 2‐chloro‐1,3‐dimethylimidazolinium chloride (DMC) is disclosed. The method has a wide substrate scope and is compatible with labile OH protecting groups, including benzyl, acetyl, benzoyl, isopropylidene, benzylidene, TBDMS (tert‐butyldimethylsilyl), and TBDPS (tert‐butyldiphenylsilyl) groups. The excellent α selectivity obtained in this reaction is attributed to in‐situ isomerization of β‐glycosyl chlorides to the more stable α‐glycosyl chlorides, as demonstrated by 1H NMR spectroscopic studies. Disarmed sugars with OBz or OAc groups at C‐2 were chlorinated at a faster rate but ismomerized (β→α) at a slower rate than armed sugars with an OBn group at C‐2. More importantly, the method enables highly desirable one‐pot glycosylation reactions to take place, thus allowing efficient syntheses of disaccharides and simple O‐glycosylated sugars in high overall yields without the need for separation or purification of the α‐glycosyl chloride donors. This method will be especially useful for direct glycosylation reactions using glycosyl chloride donors that are unstable upon separation and purification.

New μ-OAC bridged dinuclear copper(II) complex with tridentate Schiff base ligand: Synthesis, characterization, crystal structure, and CuO nano-particles formation

A new (μ-acetato)-bridged dinuclear copper(II) complex [Cu2(L)2(μ-OAc)2] (I) has been synthesized by the reaction of a tridentate N2O Schiff base ligand (HL) with Cu(OAC)2 in methanol at refluxed conditions and characterized by elemental analysis (CHN) and FT-IR spectroscopy. The crystal structure of I was investigated by single-crystal X-ray diffraction (CIF file CCDC no. 1013907). X-ray results showed that two OAC groups bridge the copper(II) ions in a Cu2O2 core of a binuclear complex. Each copper(II) ion adopts a distorted square-pyramidal geometry with one imine nitrogen, one amine nitrogen and one phenolato oxygen from the tridentate Schiff base ligand, completed by two acetate oxygen atoms. Finally, the complex was thermally decomposed in order to obtain CuO nano-particles. The particles were characterized by powder X-ray diffraction, which confirmed the formation of the CuO nano-particles with the average size of 24 nm.

Comparing the efficacy of four different protocols for eradicating of Helicobacter pylori infection in Ahvaz, southwest Iran.

IntroductionHelicobacter pylori (H. pylori) is the common cause of many gastrointestinal diseases, especially peptic ulcer. Therefore, a successful treatment of this infection decreases the financial burden on health systems.AimDifferent combinations of antibiotics are used for the eradication of this bacterium worldwide. The goal of this study is to compare the efficacy of four different protocols used for this purpose in Ahvaz.Material and methodsA total number of 400 patients with H. pylori infection were randomly divided into four groups (100 in each): (1) OAC: omeprazole (20 mg/b.i.d.), amoxicillin (1000 mg/b.i.d.), clarithromycin (500 mg/b.i.d.) for 10 days. (2) OCF: omeprazole (20 mg/b.i.d.), ciprofloxacin (500 mg/b.i.d.), furazolidone (100 mg/b.i.d.) for 10 days. (3) OBAM: omeprazole (20 mg/b.i.d.), bismuth subcitrate (240 mg/b.i.d.), amoxicillin (1000 mg/b.i.d.), metronidazol (500 mg/b.i.d.) for 14 days. (4) OBTM: omeprazole (20 mg/b.i.d.), bismuth subcitrate (240 mg/b.i.d.), tetracycline (500 mg/b.i.d.), metronidazol (500 mg/b.i.d.) for 14 days. At the end the viability of the bacterium was assessed by C14 urea breath test.ResultsThe rate of H. pylori eradication was 92%, 59%, 73%, and 76% in OAC, OCF, OBAM, and OBTM groups, respectively (based on intention to treat analysis). The eradication rate was 93.9%, 62.1%, 77.7%, and 84.4% in OAC, OCF, OBAM, and OBTM groups, respectively (based on per protocol analysis). There was a statistically significant increase in eradication rate in the OAC group in comparison with the others (p < 0.001).ConclusionsStandard triple therapy (omeprazole, amoxicillin, clarithromycin) remains the most effective regimen for H. pylori eradication in Ahvaz.

The Impact of Prior Antithrombotic Status on Cerebral Infarction in Patients with Atrial Fibrillation

Anticoagulation effectively prevents cardioembolic stroke in atrial fibrillation (AF) patients, whereas it is less effective than antiplatelet therapy (AT) in noncardioembolic stroke prevention. We hypothesized that the ischemic lesion pattern and vascular patency would differ according to the antithrombotic treatment status in AF patients. The medical records of 1078 acute ischemic stroke patients with AF were retrospectively reviewed. Patients were classified according to medication at stroke onset: (1) optimal anticoagulation (OAC; international normalized ratio [INR] 1.7-3.0; n = 36); (2) suboptimal anticoagulation (SOAC; INR ≤1.7; n = 134); (3) AT (n = 285); and (4) control (no antithrombotic medication; n = 623). Imaging and clinical variables of each group were compared with that of controls. Small cortical or single subcortical infarctions were more common in the OAC group than in controls (6% vs. 1% and 22% vs. 8%, respectively; standardized residual, 2.4 and 2.8). Multicirculatory infarctions were less common in the OAC group than in controls (0% vs. 11%; standardized residual, -2.0). Obstruction of the corresponding artery was less common in the OAC group than in controls (26.5% vs. 46.5%, P = .02). Initial neurologic severity was lower in the OAC and AT groups than in controls (P = .01 and .03, respectively). OAC and AT were independently associated with favorable functional outcome at 3-months (P = .015 and <.001, respectively). Ischemic stroke can occur during OAC in AF patients. Small cortical or single subcortical lesions were more common than typical cardioembolic lesion patterns. OAC and AT were protective against severe neurologic deficit and independently associated with favorable outcome, but SOAC was not.

Hemisynthesis of Selected Embelin Analogs and Investigation of their Proapoptotic Activity Against Cancer Cells

Embelin is a natural product, inhibitor of XIAP (X-chromosome-linked Inhibitor of APoptosis) with strong proapoptotic properties on cancer cells. In order to clarify the role of two OH groups on benzoquinone core, we have prepared by hemisynthesis close analogs of embelin, where these OH groups have been replaced in a systematic manner by OMe and OAc groups. Proapoptotic activities of six embelin derivatives have been studied as single agent, or in combination with TRAIL, and their abilities to interact with XIAP have been evaluated by Surface Plasmon Biacore. Our results show that these new embelin analogs have good proapoptotic properties against selected cancer cells, often higher than the natural product itself. Further, this activity is not directly mediated by XIAP. Altogether these preliminary results demonstrate that for active embelin analogs, the two OH groups are not absolutely required for anticancer activity, opening new possibilities for the design of proapoptotic derivatives in these series.

ChemInform Abstract: Pd(II)‐Catalyzed Dehydrogenative Olefination of Vinylic C—H Bonds with Allylic Esters: General and Selective Access to Linear 1,3‐Butadienes.

This work demonstrates a general and efficient method to prepare conjugated dienes by Pd(II)-catalyzed direct olefination of unactivated alkenes with allylic esters and acrylates via vinylic C–H activation. Various aryl and heteroaryl alkenes as well as aliphatic alkenes all give the desired linear 1,3-butadienes with retention of the traditional leaving groups such as OAc and other carboxylic acid ester groups.

Pd(II)-Catalyzed Dehydrogenative Olefination of Vinylic C–H Bonds with Allylic Esters: General and Selective Access to Linear 1,3-Butadienes

This work demonstrates a general and efficient method to prepare conjugated dienes by Pd(II)-catalyzed direct olefination of unactivated alkenes with allylic esters and acrylates via vinylic C-H activation. Various aryl and heteroaryl alkenes as well as aliphatic alkenes all give the desired linear 1,3-butadienes with retention of the traditional leaving groups such as OAc and other carboxylic acid ester groups.

Double-fold C-H oxygenation of arenes using PyrDipSi: a general and efficient traceless/modifiable silicon-tethered directing group.

The efficient Pd-catalyzed double-fold C-H oxygenation of arenes into resorcinols using the newly developed 2-pyrimidyldiisopropylsilyl (PyrDipSi) directing group is described. Its use allows for the sequential introduction of OAc and OPiv groups in a one-pot manner to produce orthogonally protected resorcinol derivatives. The PyrDipSi group is superior to the previously developed 2-pyridyldiisopropylsilyl (PyDipSi) group, as it is efficient for monooxygenation of ortho-substituted arenes. Notably, the PyrDipSi group can be easily installed into arene molecules and can be easily removed or modified after the oxygenation reaction.

The Varying Impact of Geographic Distance as a Predictor of Dissatisfaction Over Facility Access

This research uses a Geographically Weighted Regression (GWR) analysis to compare perceptions of public service accessibility as captured by an attitudes survey against measures of geographical distance to those services. The 2008 Place Survey in Leicestershire, UK, captured data on respondent dissatisfaction about their access to different services and facilities. In this analysis, survey responses about access to Post Offices and libraries were summarised over census Output Areas. Road distances to the nearest facility were calculated for each Output Area. GWR was used to model the spatial variations in the relationship between facility distance and access dissatisfaction and how these relationships vary within and between different socio-economic groups (in this case OAC groups). The results show that for Post Offices, the effect of geographic distance as a predictor of access dissatisfaction is stronger than for libraries, that its effect varies spatially and that there is considerable variation within and between different socio-economic groups. For Libraries, geographic distance is a weaker predictor of dissatisfaction over access, there is little local variation in the effect of geographic distance as a predictor of library access dissatisfaction and that there is little variation within and between different socio-economic groups. These results indicate that as well as geography, other dimensions related to facility access need to be considered and that these will vary from facility to facility and from group to group.

Efficacy of Proton Pump Inhibitor-based Triple Therapy and Bismuth-based Quadruple Therapy forHelicobacter pyloriEradication in Korean Children

PurposeThe aim of this study was to assess and compare the efficacies of proton pump inhibitor-based triple therapy and bismuth-based quadruple therapy as first-line treatments for Helicobacter pylori eradication in Korean children.MethodsWe retrospectively reviewed the data of children who had been diagnosed with H. pylori infection at the Seoul National University Bundang Hospital from March 2004 to August 2012. The patients were randomly assigned to receive either triple therapy consisting of omeprazole, amoxicillin, and clarithromycin for 2 weeks (OAC group) or quadruple therapy comprising omeprazole, amoxicillin, metronidazole, and bismuth salts for 1 week (OAMB group). The patients were evaluated for eradication of H. pylori infection at 4 weeks after the completion of the treatment.ResultsOf the 129 children enrolled in this study, 118 (91.5%) were included in the final analysis. The eradication rates in OAC and OAMB groups were 67.7% (42/62) and 83.9% (47/56), respectively, which were significantly different between the 2 treatment groups (p=0.041). The eradication rates in the OAMB group during the periods 2004-2006, 2007-2009, and 2010-2012 were superior to those in the OAC group.ConclusionThis study indicated that the 1-week bismuth-based quadruple therapy, compared with the standard 2-week triple therapy, was significantly more successful in eradicating H. pylori infection in Korean children.

Anion-dependent construction of two hexanuclear 3d–4f complexes with a flexible Schiff base ligand

Two hexanuclear 3d-4f Ni-Eu and Cu-Eu complexes [Eu(4)Ni(2)L(2)(OAc)(12)(EtOH)(2)] (1) and [Eu(4)Cu(2)L(2)(OAc)(12)]·2H(2)O (2) are reported which are formed from the salen type Schiff-base ligand H(2)L (H(2)L = N,N'-bis(3-methoxysalicylidene)butane-1,4-diamine). In both complexes, four Eu(3+) cations are bridged by eight OAc(-) groups and the chain is terminated at each end by two ML (M = Ni and Cu) units. The structures of 1 and 2 were determined by single crystal X-ray crystallographic studies and the luminescence properties of the free ligand and metal complexes in solution were measured.

Free-radical hydrothiolation of glycals: a thiol-ene-based synthesis of S-disaccharides

A method for the synthesis of a new family of 1-deoxy S-disaccharides has been established via free-radical hydrothiolation of glycals by sugar thiols (thiol-ene coupling). The photoinduced coupling between four tri- O-acetyl- d-glycals and three different sugar thiols reveals that the reaction efficiency and stereoselectivity are highly dependent on the stereochemistry of the OAc groups at C3 and C4 of the glycal.