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Marella CE van Ruissen,1,2 Sebastiaan JW van Kraaij,1,2 Pim Gal,1,2 Wouter A Bakker,1,2 Hemme J Hijma,1,2 Geert Jan Groeneveld,1,2 Marieke L de Kam,1 Jacobus Burggraaf,1,2 Matthijs Moerland1,2 1Center for Human Drug Research, Leiden, The Netherlands; 2Leiden University Medical Center, Leiden, The NetherlandsCorrespondence: Matthijs Moerland, Center for Human Drug Research, Zernikedreef 8, Leiden, 2333CL, The Netherlands, Tel +31 71 524 6400, Fax +31 71 5246 499, Email mmoerland@chdr.nlAbstract: Dermal allyl isothiocyanate (AITC) administration and whole-body heat stress (WBHS) are two challenge models that are used to evaluate physiological mechanisms of vasodilation and pharmacological activity in humans. Their exact vasodilatory mechanisms in humans are not fully elucidated but are likely to be nitric oxide (NO)-mediated. This study aimed to evaluate whether there is overlap in the vasodilatory pathways of dermal AITC application and WBHS by combining the challenges. In this open-label interventional study, healthy volunteers underwent dermal administration of AITC twice: under basal conditions and during WBHS. Dermal blood flow (DBF) was non-invasively measured using laser speckle contrast imaging four times, once in each of the following situations: baseline, WBHS only, AITC only, and WBHS combined with AITC. A total of 12 male volunteers, aged 18– 61 years, participated in the study. Compared to baseline, following AITC application, their DBF increased by 63.43 AU (baseline: 32.55, 95% CI [17.78, 47.31] AU, AITC only: 95.97, 95% CI [81.21, 110.7] AU, p < 0.0001). During WBHS, the increase in DBF after AITC was 42.76 AU (WBHS only: 87.25, 95% CI [72.49, 102.0] AU, WBHS+AITC: 130.0, 95% CI [115.2, 144.8] AU, p < 0.0001). The combination of WBHS and AITC resulted in a lower DBF than the sum of the DBF responses to AITC and WBHS when applied separately (ED 20.67, 95% CI [− 3.532, 44.88], p = 0.0916). This might point towards the presence of an interaction in the vasodilatory mechanism of AITC application and WBHS, possibly indicating overlap in their NOS-driven vasodilatory pathways.Keywords: clinical study, vasodilatory pathways, laser speckle contrast imaging, pharmacological challenge models

Background: Polyesters are applied in high-end products in many industrial applications, including resins and powder-coating applications. The characterization of the chemical heterogeneities within a polyester is of utmost interest to develop new products or improve existing applications. Unfortunately, characterization is a difficult task, as polyesters may feature distributions in end-group functionality, molecular weight, chemical composition, and degree of branching. Currently, no analytical method can characterize all these interdependent distributions in a single analysis., Results: We report the use of comprehensive normal-phase liquid chromatography × size-exclusion chromatography hyphenated with ultraviolet-light spectroscopy and high-resolution mass spectrometry in parallel (NPLC × SEC-UV/HRMS) to characterize polyesters according to their end-group-functionality and molecular-weight distributions. The chemical composition can be measured with HRMS, while relative quantitation can be performed with UV detection. A supercharging agent was used during ionization allowing to extend the molecular-weight range of the detected chemical species., Significance: The presented platform allows characterization of polyesters with varying fractions of carboxyl or hydroxyl end-group functionalities and varying distributions of molecular weight, degree of branching, and chemical compositions. The number-average and weight-average molar masses are obtained in the same analysis. This information cannot be obtained by any one-dimensional technique. The developed NPLC × SEC-UV/HRMS platform is a valuable tool for characterizing polyesters in an industrial setting., Competing Interests: Declaration of competing interest “The authors declare that they have no known competing financial interest or personal relationship that could have appeared to influence the work reported in this paper.”, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: The potential benefit of convalescent plasma (CP) therapy for coronavirus disease 2019 (COVID-19) is highest when administered early after symptom onset. Our objective was to determine the effectiveness of CP therapy in improving the disease course of COVID-19 among high-risk outpatients., Methods: A multicentre, double-blind randomized trial was conducted comparing 300 mL of CP with non-CP. Patients were ≥50 years, were symptomatic for <8 days, had confirmed RT-PCR or antigen test result for COVID-19 and had at least one risk factor for severe COVID-19. The primary endpoint was the highest score on a 5-point ordinal scale ranging from fully recovered (score = 1) or not (score = 2) on day 7, over hospital admission (score = 3), intensive care unit admission (score = 4) and death (score = 5) in the 28 days following randomization. Secondary endpoints were hospital admission, symptom duration and viral RNA excretion., Results: After the enrolment of 421 patients and the transfusion in 416 patients, recruitment was discontinued when the countrywide vaccination uptake in those aged >50 years was 80%. Patients had a median age of 60 years, symptoms for 5 days, and 207 of 416 patients received CP therapy. During the 28 day follow-up, 28 patients were hospitalized and two died. The OR for an improved disease severity score with CP was 0.86 (95% credible interval, 0.59-1.22). The OR was 0.58 (95% CI, 0.33-1.02) for patients with ≤5 days of symptoms. The hazard ratio for hospital admission was 0.61 (95% CI, 0.28-1.34). No difference was found in viral RNA excretion or in the duration of symptoms., Conclusions: In patients with early COVID-19, CP therapy did not improve the 5-point disease severity score., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when <20% of recruitment target was achieved. A Bayesian-adaptive individual patient data meta-analysis was implemented. Outpatients aged ≥50 years and symptomatic for ≤7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with ≤5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution., Trial Registration: Clinicaltrials.gov NCT04621123 and NCT04589949., Registration: NCT04621123 and NCT04589949 on https://www., Clinicaltrials: gov., (© 2022. The Author(s).)

Comprehensive two-dimensional liquid chromatography (LC × LC) is an attractive separation technique that allows achieving high peak capacities and information on chemical correlations. Unfortunately, its application in industrial practice is still not widespread due to limiting factors such as complex method development, tedious method optimization and solvent-incompatibility (such as solvent-strength mismatch or immiscibility experienced during fraction transfer). A severe case of solvent-incompatibility is encountered in the comprehensive coupling of normal-phase LC and reversed-phase LC (NPLC × RPLC). NPLC × RPLC is considered a desirable LC × LC system, especially for the characterization of synthetic polymers, due to the high orthogonality of the two retention mechanisms. However, its experimental realization often suffers from solvent-injection effects in the RPLC dimension, such as peak-deformation, peak-splitting, or even unretained elution ("breakthrough") of sample components. Such a decrease in performance or loss of retention is highly dependent on the types of solvents used. To explore the boundaries of solvent compatibility, we applied large-volume injections (LVI) of reference analytes (e.g. alkyl benzenes; ethoxylate and propoxylate polymers) dissolved in water-immiscible sample solvents, such as dichloromethane, n-hexane, and isooctane in fast water-based gradient RPLC separations (using methanol or acetonitrile as eluent). It was found that, when using highly aqueous initial gradient conditions, hydrophobic sample diluents were retained and eluted during the applied gradient. Depending on the relative retention of the retained diluent and the sample analytes, good chromatograms for LVI of immiscible solvents were obtained, comparable with injections under ideal conditions. The conclusions from injection experiments in aqueous RPLC were verified by coupling an NPLC system with a gradient from isooctane to tetrahydrofuran and an RPLC system with a gradient from water to acetonitrile in an online comprehensive NPLC × RPLC separation of a mixture of propoxylate polymers. The separation provided separation of the polymers based on their number of hydroxyl end-groups (NPLC) and oligomer chain-length (RPLC), without suffering from significant band-broadening effects due to solvent-mismatch upon injection in the second-dimension RPLC system., Competing Interests: Declaration of Competing Interest Statement: “The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”, (Copyright © 2022. Published by Elsevier B.V.)

Understanding the relation between chemical characteristics and properties of synthetic polymers is one of the challenges faced by analytical chemists in industry. This is a complex task, as polymers are not synthesized as single molecule, but are populations of chemically similar compounds with distributions over several properties. The latter include, for example, molecular weight, nature of end-groups (functionality), and chemical composition. In this paper, comprehensive two-dimensional liquid chromatography was used to determine the combined functionality-type and molecular-weight distributions of hydroxy‑functionalized propoxylates. Propoxylates derived from different initiators (one up to eight terminal hydroxyl groups) were separated in the first dimension using a gradient normal-phase LC separation (NPLC). In the second dimension ultra-high pressure size-exclusion chromatography separation (UHPSEC), further speciating distributions based on molecular size. The developed NPLC × SEC method with evaporative light-scattering detection can be used for the fast screening (< 30 min) of mutually dependent functionality-type and molecular-weight distributions of unknown propoxylates., Competing Interests: Declaration of Competing Interest Statement: “The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”, (Copyright © 2021. Published by Elsevier B.V.)