Regioselective Glycosylation Strategies for the Synthesis of Group Ia and Ib Streptococcus Related Glycans Enable Elucidating Unique Conformations of the Capsular Polysaccharides

Group B Streptococcus serotypes Ia and Ib capsular polysaccharides are key targets for vaccine development. In spite of their immunospecifity these polysaccharides share high structural similarity. Both are composed of the same monosaccharide residues and differ only in the connection of the Neu5Acα2-3Gal side chain to the GlcNAc unit, which is a β1-4 linkage in serotype Ia and a β1-3 linkage in serotype Ib. We described development of efficient regioselective routes for GlcNAcβ1-3[Glcβ1-4)]Gal synthons giving access to different GBS Ia and Ib repeating unit frameshifts. These glycans were used to probe the conformation and molecular dynamics of the two polysaccharides, highlighting the different presentation of the protruding Neu5Acα2-3Gal moieties on the polysaccharide backbones and a higher flexibility of Ib polymer compared to Ia which can impact epitope exposure.Bio-organic Synthesi

Metabolic syndrome detection with biomarkers in childhood cancer survivors

Purpose: Augmented survival of childhood nephroblastoma and neuroblastoma has increased long-term side effects such as metabolic syndrome (MetS). Risk stratification is difficult after abdominal radiation because waist circumference underestimates adiposity. We aimed to develop a strategy for determining MetS in irradiated survivors using an integrated biomarker profile and vascular ultrasonography. Methods: The NCEP-ATPIII MetS-components, 14 additional serum biomarkers and 9 vascular measurements were assessed in a single-centre cohort of childhood nephroblastoma (n = 67) and neuroblastoma (n = 36) survivors and controls (n = 61). Multivariable regression models were used to study treatment effects. Principal component analysis (PCA) was used to study all biomarkers in a combined analysis, to identify patterns and correlations. Results: After 27.5 years of follow-up, MetS occurred more often in survivors (14%) than controls (3%). Abdominal radiotherapy and nephrectomy, to a lesser extent, were associated with MetS and separate components and with several biomarker abnormalities. PCA of biomarkers revealed a pattern on PC1 from favourable lipid markers (HDL-cholesterol, adiponectin) towards unfavourable markers (triglycerides, LDL-cholesterol, apoB, uric acid). Abdominal radiotherapy was associated with the unfavourable biomarker profile (β = 1.45, P = 0.001). Vascular measurements were not of added diagnostic value. Conclusions: Long-term childhood nephro-and neuroblastoma survivors frequently develop MetS. Additional assessment of biomarkers identified in PCA – adiponectin, LDL, apoB, and uric acid – may be used especially in abdominally irradiated survivors, to classify MetS as alternative for waist circumference. Vascular ultrasonography was not of added value

The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke

Objective: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. Methods: A JBA was defined as an area of pixels with a grayscale value <25 adjacent to the lumen without a visible echogenic cap after image normalization. The size of a JBA was measured in the carotid plaque images of 1121 patients with asymptomatic carotid stenosis 50% to 99% in relation to the bulb (Asymptomatic Carotid Stenosis and Risk of Stroke study); the patients were followed for up to 8 years. Results: The JBA had a linear association with future stroke rate. The area under the receiver-operating characteristic curve was 0.816. Using Kaplan-Meier curves, the mean annual stroke rate was 0.4% in 706 patients with a JBA <4 mm 2, 1.4% in 171 patients with a JBA 4 to 8 mm2, 3.2% in 46 patients with a JBA 8 to 10 mm2, and 5% in 198 patients with a JBA >10 mm2 (P <.001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (<4 mm2, 4-8 mm2, >8 mm2) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was <1% in 734 patients, 1% to 1.9% in 94 patients, 2% to 3.9% in 134 patients, 4% to 5.9% in 125 patients, and 6% to 10% in 34 patients. Conclusions: The size of a JBA is linearly related to the risk of stroke and can be used in risk stratification models. These findings need to be confirmed in future prospective studies or in the medical arm of randomized controlled studies in the presence of optimal medical therapy. In the meantime, the JBA may be used to select asymptomatic patients at high stroke risk for carotid endarterectomy and spare patients at low risk from an unnecessary operation

Effectiveness of medication withdrawal in older fallers: Results from the improving medication prescribing to reduce risk of falls (IMPROveFALL) trial

Objectives: to investigate the effect of withdrawal of fall-risk-increasing-drugs (FRIDs) versus 'care as usual' on reducing falls in community-dwelling older fallers. Design: randomised multicentre trial. Participants: six hundred and twelve older adults who visited an Emergency Department (ED) because of a fall. Interventions: withdrawal of FRIDs. Main Outcomes and Measures: primary outcome was time to the first self-reported fall. Secondary outcomes were time to the second self-reported fall and to falls requiring a general practitioner (GP)-consultation or ED-visit. Intention-to-treat (primary) and a per-protocol (secondary) analysis were conducted. The hazard ratios (HRs) for time-to-fall were calculated using a Cox-regression model. Differences in cumulative incidence of falls were analysed using Poisson regression. Results: during 12 months follow-up, 91 (34%) control and 115 (37%) intervention participants experienced a fall; 35% of all attempted interventions were unsuccessful, either due to recurrence of the initial indication for prescribing, additional medication for newly diagnosed conditions or non-compliance. Compared to baseline, the overall percentage of users of =3 FRIDs at 12 months did not change in either the intervention or the control group. Our intervention did not have a significant effect on time to first fall (HR 1.17; 95% confidence interval 0.89-1.54), time to second fall (1.19; 0.78-1.82), time to first fall-related GP-consultation (0.66; 0.42-1.06) or time to first fall-related ED-visit (0.85; 0.43-1.68). Conclusion: in this population of complex multimorbid patients visiting an ED because of a fall, our single intervention of FRIDs-withdrawal was not effective in reducing falls

Crystal Structures and DFT calculations of new chlorido-dimethylsulfoxide-M(III) (M= Ir, Ru, Rh) complexes with the N-pyrazolyl pyrimidine donor ligand: kinetic vs. thermodynamic isomers

[eng] New chlorido-dimethylsulfoxide-iridium(III), ruthenium(III) and rhodium(III) complexes with the 2-(1H-pyrazol-1-yl)-pyrimidine (pyrapyr) ligand (OC-6-N1)-[RhIIICl3(DMSO-κS)(pyrapyr)] (1a, N = 3 and 1b, N = 4); (OC-6-N1)-[RuIIICl3(DMSO-κS)(pyrapyr)] (2a, N = 3 and 2b, N = 4) and (OC-6-N1)-[IrIIICl3(DMSO-κS)(pyrapyr)] (3a, N = 3 and 3b, N = 4) have been synthesized and characterized by spectroscopic techniques and by single crystal X-ray diffraction studies (1a, 1b, 2a, 2b, a disordered crystal 3a/3b and a cocrystal 3a·3b). In all cases, the metal centers show octahedral geometry coordinated to three chloride ligands and one S coordinated dimethylsulfoxide (DMSO-κS). The coordination sphere of the metal is completed by the pyrapyr molecule. Two different coordination modes are observed: (i) the DMSO-κS is opposite to the pyrimidinic N atom (IUPAC nomenclature is OC-6-31 denoted herein as trans); (ii) DMSO-κS is opposite to the pyrazolic N atom (IUPAC nomenclature is OC-6-41 denoted as cis). For Rh(III) the kinetic product (cis) yields the thermodynamic (trans) upon heating a solution of the kinetic product and both isomers have been X-ray characterized. Conversely for Ru(III), both kinetic and thermodynamic complexes have been obtained by using different procedures. Both isomers have been characterized by X-ray crystallography and the kinetic product does not yield the thermodynamic upon heating a solution of the former. Furthermore, the Ir(III) behaves differently, since both isomers are energetically equivalent and both isomers co-crystallize in the solid state. The kinetic/thermodynamic mechanism that yields the different isomers has been studied by using theoretical DFT calculations for each metal. Finally, two Ru(II) complexes (OC-6-N1)-[RuIICl2(DMSO-κS)2(pyrapyr)] (4a, N = 3 and 4b, N = 4) are also described and X-ray characterized. They were obtained as minor products during the synthesis of 2a

Effectiveness of medication withdrawal in older fallers: Results from the improving medication prescribing to reduce risk of falls (IMPROveFALL) trial

Objectives: to investigate the effect of withdrawal of fall-risk-increasing-drugs (FRIDs) versus 'care as usual' on reducing falls in community-dwelling older fallers. Design: randomised multicentre trial. Participants: six hundred and twelve older adults who visited an Emergency Department (ED) because of a fall. Interventions: withdrawal of FRIDs. Main Outcomes and Measures: primary outcome was time to the first self-reported fall. Secondary outcomes were time to the second self-reported fall and to falls requiring a general practitioner (GP)-consultation or ED-visit. Intention-to-treat (primary) and a per-protocol (secondary) analysis were conducted. The hazard ratios (HRs) for time-to-fall were calculated using a Cox-regression model. Differences in cumulative incidence of falls were analysed using Poisson regression. Results: during 12 months follow-up, 91 (34%) control and 115 (37%) intervention participants experienced a fall; 35% of all attempted interventions were unsuccessful, either due to recurrence of the initial indication for prescribing, additional medication for newly diagnosed conditions or non-compliance. Compared to baseline, the overall percentage of users of =3 FRIDs at 12 months did not change in either the intervention or the control group. Our intervention did not have a significant effect on time to first fall (HR 1.17; 95% confidence interval 0.89-1.54), time to second fall (1.19; 0.78-1.82), time to first fall-related GP-consultation (0.66; 0.42-1.06) or time to first fall-related ED-visit (0.85; 0.43-1.68). Conclusion: in this population of complex multimorbid patients visiting an ED because of a fall, our single intervention of FRIDs-withdrawal was not effective in reducing falls