Kinetics of glucose oxidase catalyzed electron transfer mediated by sulfur and selenium compounds

AbstractUnusually high electron transfer rates in Aspergillus niger glucose oxidase catalyzed oxidation of glucose using 5,6:11,12-Bis(dithio)tetracene (TTT), 1,2-dimethyltetraselenafulvalene (DMTSF) and tetrathiafulvalene (TTF) were observed. At pH 7.0 oxidation rate constants (TN/Km) in the range from 1.0 · 107 to 8.7 · 107 M · s−1 were deduced from experimental data. One of the investigated mediators, DMTSF, has been used for electrocatalytical glucose oxidation on graphite at a potential of 0.3 V vs. a standard calomel electrode (SCE). The prepared bioelectrodes have a sensitivity of 1.3 μA/(cm2 · mM), a pH optimum at 6.5-7.0, and a linear range which covers the relevant range for monitoring physiological levels of glucose. The bioelectrodes are stable for more than one month

Effects of liraglutide compared with placebo on events of acute gallbladder or biliary disease in patients with type 2 diabetes at high risk for cardiovascular events in the LEADER randomized trial. Diabetes Care 2019;42:1912-1920

Skelin et al. have raised an important issue about competing risk in time-to-event analyses of acute gallbladder or biliary disease in the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial. We thank them for the opportunity to discuss the data in the light of competing risk from a lower frequency of all-cause death with liraglutide compared with placebo in LEADER

Impact of microvascular disease on cardiovascular outcomes in type 2 diabetes: Results from the LEADER and SUSTAIN 6 clinical trials

The randomized, double-blind, cardiovascular outcomes trials LEADER (NCT01179048) and SUSTAIN 6 (NCT01720446) showed cardiovascular risk reduction in patients with type 2 diabetes treated with liraglutide and semaglutide, respectively, compared with placebo. This post hoc analysis examined the impact of microvascular disease at baseline on cardiovascular outcomes in these trials, and the efficacy of liraglutide (1.8 mg) and once-weekly semaglutide (0.5-1.0 mg) in patients with and without microvascular disease. In total, 9340 patients from LEADER and 3297 patients from SUSTAIN 6 were included in this analysis; of these, 5761 and 2356 had a history of microvascular disease at baseline and 3835 and 1640 had a history of both microvascular and macrovascular disease, respectively. Patients with microvascular disease were shown to have an increased risk of major adverse cardiovascular events compared with patients without microvascular disease (hazard ratio [95% confidence interval] in LEADER: 1.15 [1.03; 1.29], P =.0136; SUSTAIN 6: 1.56 [1.14; 2.17], P =.0064). Liraglutide and semaglutide consistently reduced cardiovascular risk in patients with and without microvascular disease

Structural model of dodecameric heat-shock protein Hsp21:Flexible N-terminal arms interact with client proteins while C-terminal tails maintain the dodecamer and chaperone activity

Small heat-shock proteins (sHsps) prevent aggregation of thermosensitive client proteins in a first line of defense against cellular stress. The mechanisms by which they perform this function have been hard to define due to limited structural information; currently, there is only one high-resolution structure of a plant sHsp published, that of the cytosolic Hsp16.9. We took interest in Hsp21, a chloroplast-localized sHsp crucial for plant stress resistance, which has even longer N-terminal arms than Hsp16.9, with a functionally important and conserved methionine-rich motif. To provide a framework for investigating structure-function relationships of Hsp21 and understanding these sequence variations, we developed a structural model of Hsp21 based on homology modeling, cryo-EM, cross-linking mass spectrometry, NMR, and small-angle X-ray scattering. Our data suggest a dodecameric arrangement of two trimer-of-dimer discs stabilized by the C-terminal tails, possibly through tail-to-tail interactions between the discs, mediated through extended IXVXI motifs. Our model further suggests that six N-terminal arms are located on the outside of the dodecamer, accessible for interaction with client proteins, and distinct from previous undefined or inwardly facing arms. To test the importance of the IXVXI motif, we created the point mutant V181A, which, as expected, disrupts the Hsp21 dodecamer and decreases chaperone activity. Finally, our data emphasize that sHsp chaperone efficiency depends on oligomerization and that client interactions can occur both with and without oligomer dissociation. These results provide a generalizable workflow to explore sHsps, expand our understanding of sHsp structural motifs, and provide a testable Hsp21 structure model to inform future investigations

Occurence of First and Recurrent Major Adverse Cardiovascular Events with Liraglutide Treatment among Patients with Type 2 Diabetes and High Risk of Cardiovascular Events: A Post Hoc Analysis of a Randomized Clinical Trial

Importance: After the occurrence of nonfatal cardiovascular events, recurrent events are highly likely. Most cardiovascular outcomes trials analyze first events only; extending analyses to first and recurrent (total) events can provide clinically meaningful information. Objective: To investigate whether liraglutide is associated with reduced first and recurrent total major adverse cardiovascular events (MACE) compared with placebo among patients with type 2 diabetes and high risk of cardiovascular events. Design, Setting, and Participants: This post hoc analysis of the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) randomized, double-blind, clinical trial included data from patients with type 2 diabetes who had established or were at high risk for cardiovascular disease at 410 sites in 32 countries from August 2010, to December 2015. Data analysis was performed from August 15, 2016, to July 5, 2019. Interventions: Patients were randomized 1:1 to receive liraglutide (up to 1.8 mg per day) or placebo, both with standard care, for 3.5 to 5.0 years. Main Outcomes and Measures: Assessed outcomes were MACE (cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke), expanded MACE (primary MACE plus coronary revascularization and hospitalization for heart failure or unstable angina pectoris), and the individual end points. Results: The 9340 LEADER trial participants (6003 [64.3%] male; mean [SD] age, 64.3 [7.2] years) experienced 1605 total MACE (1302 first and 303 recurrent events; median follow-up, 3.8 years [range, 0-5.2 years]). Patients who experienced any MACE were older (1 MACE: mean [SD] age, 65.6 [8.0] years; >1 MACE: 65.7 [7.9] years) and had diabetes for longer duration (1 MACE: mean [SD] duration, 13.4 [8.3] years; >1 MACE: 14.4 [8.7] years) compared with patients without MACE (mean [SD] age, 64.1 [7.1] years; mean [SD] duration, 12.7 [7.9] years). Fewer first and recurrent MACE occurred in the liraglutide group (n = 4668; 608 first and 127 recurrent events) than in the placebo group (n = 4672; 694 first and 176 recurrent events). Liraglutide was associated with a 15.7% relative risk reduction in total MACE (hazard ratio [HR], 0.84; 95% CI, 0.76-0.93) and a 13.4% reduction in total expanded MACE (HR, 0.87; 95% CI, 0.81-0.93) compared with placebo. For most individual cardiovascular end points, liraglutide was associated with lower risk vs placebo. Conclusions and Relevance: These results suggest that liraglutide treatment is associated with reduced total MACE compared with placebo among patients with type 2 diabetes and high risk of cardiovascular events. This analysis supports the findings of an absolute benefit of liraglutide treatment with respect to the overall burden of cardiovascular events in this high-risk patient population

Applying REWIND cardiovascular disease criteria to SUSTAIN 6 and PIONEER 6: An exploratory analysis of cardiovascular outcomes with semaglutide

In the REWIND trial, dulaglutide reduced cardiovascular (CV) risk versus placebo in patients with type 2 diabetes in both the “established CV disease” (CVD) and “CV risk factor” subgroups. The SUSTAIN 6 and PIONEER 6 trials of semaglutide used different criteria for established CVD from those used in REWIND. The present post hoc analysis assessed the effect of semaglutide on major adverse CV events (MACE) in a pooled population of SUSTAIN 6 and PIONEER 6 patients, re-categorized into CV risk subgroups using the REWIND CVD criteria. In the pooled analysis (n = 6480), a lower percentage of patients were in the established CVD subgroup, when using the REWIND CVD criteria, compared with the original trial CVD criteria (66.5% vs. 83.8%, respectively). After re-categorization, the risk of MACE was significantly lower with semaglutide versus placebo in the established CVD subgroup (hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.59, 0.92) and nonsignificantly lower in the CV risk factor subgroup (HR 0.84, 95% CI 0.55, 1.28) (P-interaction = 0.60). These results suggest that the CV effects of semaglutide may extend to patients with type 2 diabetes across the CV risk continuum

On modulational instability and energy localization in anharmonic lattices at finite energy density

The localization of vibrational energy, induced by the modulational instability of the Brillouin-zone-boundary mode in a chain of classical anharmonic oscillators with finite initial energy density, is studied within a continuum theory. We describe the initial localization stage as a gas of envelope solitons and explain their merging, eventually leading to a single localized object containing a macroscopic fraction of the total energy of the lattice. The initial-energy-density dependences of all characteristic time scales of the soliton formation and merging are described analytically. Spatial power spectra are computed and used for the quantitative explanation of the numerical results.Comment: 12 pages, 7 figure

Effects of liraglutide on cardiovascular outcomes in type 2 diabetes patients with and without baseline metformin use: Post hoc analyses of the LEADER trial

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) reduce cardiovascular (CV) events among patients with type 2 diabetes and high CV risk. Because consensus professional society recommendations endorse metformin as the first-line medication for type 2 diabetes, the CV efficacy of GLP-1RAs has primarily been studied with background metformin therapy. However, the European Society of Cardiology now recommends GLP-1RAs as a first-line type 2 diabetes treatment for patients at high CV risk. These discordant recommendations raise the question of how background metformin might influence the CV benefits of GLP-1RAs. Using data from the LEADER trial,we sought to answer this question by exploring possible heterogeneity in the CV efficacy of liraglutide related to baseline metformin treatment

MethCORR modelling of methylomes from formalin-fixed paraffin-embedded tissue enables characterization and prognostication of colorectal cancer

Transcriptional characterization and classification has potential to resolve the inter-tumor heterogeneity of colorectal cancer and improve patient management. Yet, robust transcriptional profiling is difficult using formalin-fixed, paraffin-embedded (FFPE) samples, which complicates testing in clinical and archival material. We present MethCORR, an approach that allows uniform molecular characterization and classification of fresh-frozen and FFPE samples. MethCORR identifies genome-wide correlations between RNA expression and DNA methylation in fresh-frozen samples. This information is used to infer gene expression information in FFPE samples from their methylation profiles. MethCORR is here applied to methylation profiles from 877 fresh-frozen/FFPE samples and comparative analysis identifies the same two subtypes in four independent cohorts. Furthermore, subtype-specific prognostic biomarkers that better predicts relapse-free survival (HR = 2.66, 95%CI [1.67-4.22], P value < 0.001 (log-rank test)) than UICC tumor, node, metastasis (TNM) staging and microsatellite instability status are identified and validated using DNA methylation-specific PCR. The MethCORR approach is general, and may be similarly successful for other cancer types