Publications by authors named "James Gilbert"

177 Publications

The von Willebrand Factor A-1 domain binding aptamer BT200 elevates plasma levels of VWF and Factor VIII: a first-in-human trial.

Haematologica 2021 Nov 25. Epub 2021 Nov 25.

Department of Clinical Pharmacology.

Von Willebrand Factor (VWF) and Factor VIII (FVIII) circulate in a noncovalent complex in blood and promote primary haemostasis and clotting respectively. A new VWF A1-domain binding aptamer, BT200, demonstrated good subcutaneous bioavailability and a long half-life in non-human primates. This first-in-human, randomised, placebo-controlled, double-blind trial tested the hypothesis that BT200 is well tolerated and has favourable pharmacokinetic and pharmacodynamic effects in 112 volunteers. Participants received one of the following: Single ascending dose of BT200 (0.18-48mg) subcutaneously, an intravenous dose, BT200 with concomitant desmopressin or multiple doses. Pharmacokinetics were characterised, and the pharmacodynamic effects were measured by VWF levels, FVIII clotting activity, ristocetin induced aggregation, platelet function under high shear rates, and thrombin generation. Mean half-lives ranged from 7-12 days and subcutaneous bioavailability increased dosedependently exceeding 55% for doses of 6-48 mg. By blocking free A1 domains, BT200 dose-dependently decreased ristocetin-induced aggregation, and prolonged collagenadenosine diphosphate and shear-induced platelet plug formation times. However, BT200 also increased VWF antigen and FVIII levels 4-fold (p.
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http://dx.doi.org/10.3324/haematol.2021.279948DOI Listing
November 2021

Considerations in the Management of a Kidney Transplant Patient With HIV.

Cureus 2021 Oct 13;13(10):e18744. Epub 2021 Oct 13.

Medical Sciences, University of Oxford, Oxford, GBR.

In the wake of highly active antiretroviral therapy (HAART), kidney transplantation has become common practice in HIV-positive recipients. However, management is more complex than that of a seronegative recipient in the pre-operative, peri-operative, and post-operative periods. Although the standard HAART regimen is often modified to improve outcomes and reduce interactions with the post-transplant immunosuppressive regimen, kidney transplantation in HIV-positive individuals is feasible, with high graft survival rates comparable to those in their seronegative counterparts. There is also increasing interest in the possibility of HIV-positive kidney donation, which could increase the donor pool in seropositive patients with end-stage renal disease. This report highlights considerations in the management of a seropositive kidney recipient, reviewing the evidence that underpins current treatment guidelines and highlighting the role of HAART in the dramatic change in attitude towards transplantation in this population. It also addresses studies from multiple countries which have shown favourable outcomes in transplants from HIV-positive donors. This warrants further investigation into seropositive-to-seropositive transplantation as a potential therapeutic option.
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http://dx.doi.org/10.7759/cureus.18744DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8513352PMC
October 2021

Assisted dying: society and parliament to decide the particular circumstances.

Authors:
James Gilbert

BMJ 2021 10 15;375:n2494. Epub 2021 Oct 15.

University of Exeter, Exeter, UK.

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http://dx.doi.org/10.1136/bmj.n2494DOI Listing
October 2021

First Clinical Results of the Merit WRAPSODY™ Cell-Impermeable Endoprosthesis for Treatment of Access Circuit Stenosis in Haemodialysis Patients.

Cardiovasc Intervent Radiol 2021 Dec 12;44(12):1903-1913. Epub 2021 Sep 12.

General Hospital of Athens "G.Gennimatas", Athens, Greece.

Purpose: This prospective, observational first in human study evaluated the safety and effectiveness of WRAPSODY Cell-impermeable Endoprosthesis (Merit Medical Systems, Inc.) in the treatment of arteriovenous fistula and arteriovenous graft access circuit stenosis.

Materials And Methods: Investigators conducted a prospective analysis of 46 patients with access circuit stenosis from three centres. Treatment sites included the peripheral outflow veins (e.g. cephalic arch, basilic vein swing point; 16 fistula and 10 graft patients); the graft-vein anastomosis (9 patients); and the central veins (up to, but not including the SVC; 11 patients). Primary outcome measures included 30-day freedom from access circuit-related safety events and 30-day target lesion primary patency. Secondary outcome measures included procedural success; device- and procedure-related adverse events; target lesion primary patency; access circuit primary patency; and secondary patency. In-person follow-up was scheduled at 1, 3, 6, and 12 months. An independent data monitoring/clinical event committee adjudicated all reinterventions and device/procedure-relatedness for adverse events.

Results: All initial procedures were successful. All but one patient was free from safety events through the first 30 days (97.8% (45/46)). This event was not device-related. Over the remainder of the study, one adverse event was adjudicated as possibly device-related. Six- and 12-month target lesion primary patency rates were 97.7% (42/43) and 84.6.% (33/39), respectively. Six- and 12-month access circuit primary patency rates were 84.4% (38/45) and 65.9% (29/44), respectively.

Conclusion: Results suggest that the study device is safe and effective for treatment of stenoses in the peripheral and central veins of arteriovenous access circuits.

Level Of Evidence: Level 2b, cohort study.
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http://dx.doi.org/10.1007/s00270-021-02953-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8626397PMC
December 2021

A UK Expert Consensus Approach for Managing Symptomatic Arteriovenous Fistula (AVF) Stenosis in Haemodialysis Patients.

Cardiovasc Intervent Radiol 2021 Nov 6;44(11):1736-1746. Epub 2021 Jul 6.

King's College Hospital NHS Foundation Trust, London, UK.

Purpose: Stenoses in mature arteriovenous fistulas (AVFs) are common and can negatively impact on the quality of haemodialysis, the longevity of the AVF and lead to debilitating symptoms. Multiple treatment options exist; however, management can vary between different centres. We aimed to establish multidisciplinary consensus on the optimal stepwise application of interventions based on evidence and consensus.

Methods: A modified Delphi process was conducted with 13 participants from hospitals across the UK, all of whom have high-volume dialysis access practice.

Results: The usual intervention to rectify de novo stenoses of mature AVFs is fistuloplasty, although surgery for inflow segment stenoses is also clinically acceptable. Appropriate first-line interventions include plain old balloon angioplasty or high-pressure balloon angioplasty; if these fail during the fistuloplasty, consider upsizing the balloon, prolonged balloon inflation or using alternative interventions, such as cutting or scoring balloons and ultra-high-pressure balloons. Alternative or subsequent interventions vary by anatomical site and may require additional multidisciplinary team input. For a stenoses recurring between 3 and 12 months, it is appropriate to consider interventions used de novo, but with a lower threshold for using drug-coated balloons (DCBs) in all regions and for using stent grafts in all regions but inflow segment. Recurrence after 12 months should be treated as a de novo lesion, with DCBs considered if they have been used successfully during previous interventions.

Conclusions: These recommendations aim to provide a practical guide to multidisciplinary teams in order to optimise the use of multiple interventions for rectifying AVF stenoses and provide unified evidence-based practice guidelines.
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http://dx.doi.org/10.1007/s00270-021-02875-5DOI Listing
November 2021

Exploring real-world evidence to uncover unknown drug benefits and support the discovery of new treatment targets for depressive and bipolar disorders.

J Affect Disord 2021 07 2;290:324-333. Epub 2021 May 2.

Janssen Research & Development, LLC., Neuroscience, San Diego, CA, USA.

Background: Major depressive and bipolar disorders are associated with impaired quality of life and high economic burden. Although progress has been made in our understanding of the underlying pathophysiology and the development of novel pharmacological treatments, a large unmet need remains for finding effective treatment options. The purpose of this study was to identify potential new mechanisms of actions or treatment targets that could inform future research and development opportunities for major depressive and bipolar disorders.

Methods: A self-controlled cohort study was conducted to examine associations between 1933 medications and incidence of major depressive and bipolar disorders across four US insurance claims databases. Presence of incident depressive or bipolar disorders were captured for each patient prior to or after drug exposure and incident rate ratios were calculated. Medications that demonstrated ≥50% reduction in risk for both depressive and bipolar disorders within two or more databases were evaluated as potential treatment targets.

Results: Eight medications met our inclusion criteria, which fell into three treatment groups: drugs used in substance use disorders; drugs that affect the cholinergic system; and drugs used for the management of cardiovascular-related conditions.

Limitations: This study was not designed to confirm a causal association nor inform current clinical practice. Instead, this research and the methods employed intended to be hypothesis generating and help uncover potential treatment pathways that could warrant further investigation.

Conclusions: Several potential drug targets that could aid further research and discovery into novel treatments for depressive and bipolar disorders were identified.
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http://dx.doi.org/10.1016/j.jad.2021.04.096DOI Listing
July 2021

RTP801 regulates motor cortex synaptic transmission and learning.

Exp Neurol 2021 08 11;342:113755. Epub 2021 May 11.

Department of Biomedicine, Faculty of Medicine, University of Barcelona, Catalonia, Spain; Institut de Neurociències, University of Barcelona, 08036, Catalonia, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, 08036, Catalonia, Spain. Electronic address:

Background: RTP801/REDD1 is a stress-regulated protein whose upregulation is necessary and sufficient to trigger neuronal death in in vitro and in vivo models of Parkinson's and Huntington's diseases and is up regulated in compromised neurons in human postmortem brains of both neurodegenerative disorders. Indeed, in both Parkinson's and Huntington's disease mouse models, RTP801 knockdown alleviates motor-learning deficits.

Results: We investigated the physiological role of RTP801 in neuronal plasticity and we found RTP801 in rat, mouse and human synapses. The absence of RTP801 enhanced excitatory synaptic transmission in both neuronal cultures and brain slices from RTP801 knock-out (KO) mice. Indeed, RTP801 KO mice showed improved motor learning, which correlated with lower spine density but increased basal filopodia and mushroom spines in the motor cortex layer V. This paralleled with higher levels of synaptosomal GluA1 and TrkB receptors in homogenates derived from KO mice motor cortex, proteins that are associated with synaptic strengthening.

Conclusions: Altogether, these results indicate that RTP801 has an important role modulating neuronal plasticity and motor learning. They will help to understand its role in neurodegenerative disorders where RTP801 levels are detrimentally upregulated.
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http://dx.doi.org/10.1016/j.expneurol.2021.113755DOI Listing
August 2021

eDNAir: proof of concept that animal DNA can be collected from air sampling.

PeerJ 2021 31;9:e11030. Epub 2021 Mar 31.

School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.

Environmental DNA (eDNA) is one of the fastest developing tools for species biomonitoring and ecological research. However, despite substantial interest from research, commercial and regulatory sectors, it has remained primarily a tool for aquatic systems with a small amount of work in substances such as soil, snow and rain. Here we demonstrate that eDNA can be collected from air and used to identify mammals. Our proof of concept successfully demonstrated that eDNA sampled from air contained mixed templates which reflect the species known to be present within a confined space and that this material can be accessed using existing sampling methods. We anticipate this demonstration will initiate a much larger research programme in terrestrial airDNA sampling and that this may rapidly advance biomonitoring approaches. Lastly, we outline these and potential related applications we expect to benefit from this development.
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http://dx.doi.org/10.7717/peerj.11030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019316PMC
March 2021

Taste dysfunction following radiotherapy to the head and neck: A systematic review.

Radiother Oncol 2021 04 3;157:130-140. Epub 2021 Feb 3.

Head and Neck Unit, The Royal Marsden London, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.

Background: An intact sense of taste provides pleasure, supports sustenance and alerts the body to toxins. Head and neck cancer (HNC) patients who receive radiotherapy (RT) are high-risk for developing radiation-induced taste dysfunction. Advances in RT offer opportunities for taste-preserving strategies by reducing dose to the gustatory organs-at-risk.

Methods: PubMed, Medline and EMBASE were searched for publications reporting on taste, RT and HNC. Randomised trials, cohort studies and cross-sectional studies were included.

Results: 31 studies were included in this review. Meta-analysed prevalence of acute taste dysfunction following RT was approximately 96% (95% CI 64 to 100%) by objective measures and 79% (95% CI 65 to 88%) by subjective measures, with the majority of patients showing at least partial recovery. Long-term dysfunction was seen in ~25% of patients. Taste dysfunction was associated with sequalae including weight loss and reduced quality-of-life (QoL). Taste dysfunction was more common when the oral cavity, and specifically the anterior two-thirds of the tongue, was irradiated, suggesting a dose constraint for taste preservation might be feasible. Proton beam therapy and customised bite blocks reduced dose to the gustatory field and subsequent loss of taste.

Conclusions: Taste dysfunction following RT is common and negatively affects patients' nutritional status and QoL. Decisions about treatment strategies, including choice of RT modality, dose distribution across the gustatory field and the use of adjuncts like bite blocks may be beneficial. However, evidence is limited. There is a pressing need for randomised studies or large prospective cohort studies with sufficient adjustment for confounders.
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http://dx.doi.org/10.1016/j.radonc.2021.01.021DOI Listing
April 2021

The aptamer BT200 blocks von Willebrand factor and platelet function in blood of stroke patients.

Sci Rep 2021 02 4;11(1):3092. Epub 2021 Feb 4.

Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.

The effect of conventional anti-platelet agents is limited in secondary stroke prevention, and their effects are blunted under high shear stress in the presence of increased levels of circulating von Willebrand factor (VWF). VWF is critically involved in thrombus formation at sites of stenotic extracranial/intracranial arteries. A third generation anti-VWF aptamer (BT200) has been generated which could be useful for secondary stroke prevention. To characterize the effects of BT200 in blood of patients with large artery atherosclerosis stroke (LAA). Blood samples were obtained from 33 patients with acute stroke or transient ischemic attack to measure inhibition of VWF activity and VWF-dependent platelet function. Patients who received clopidogrel or dual antiplatelet therapy did not differ in VWF dependent platelet function tests from aspirin treated patients. Of 18 patients receiving clopidogrel with or without aspirin, only 3 had a prolonged collagen adenosine diphosphate closure time, and none of the patients had ristocetin induced aggregation in the target range. BT200 concentration-dependently reduced median VWF activity from 178 to < 3%, ristocetin induced platelet aggregation from 40U to < 10U and prolonged collagen adenosine diphosphate closure times from 93 s to > 300 s. Baseline VWF activity correlated (r = 0.86, p < 0.001) with concentrations needed to reduce VWF activity to < 20% of normal, indicating that BT200 acts in a target concentration-dependent manner. Together with a long half-life supporting once weekly administration, the safety and tolerability observed in an ongoing phase I trial, and the existence of a reversal agent, BT200 is an interesting drug candidate.
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http://dx.doi.org/10.1038/s41598-021-82747-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862663PMC
February 2021

The relationship between individual phenotype and the division of labour in naked mole-rats: it's complicated.

PeerJ 2020 29;8:e9891. Epub 2020 Sep 29.

School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.

Background: The naked mole-rat ( is among the most social mammals on the planet, living in eusocial groups of up to 300 individuals that contain a single reproductive female and up to three reproductive males. A critical aspect of their complex social system is the division of labour that allows non-breeders to form an effective workforce. Age- or weight-based polyethisms are widely cited as explanations for how labour is divided, but evidence in support of these hypotheses has been equivocal.

Methods: To assess the extent to which individual working behaviour is determined by sex, age, weight and social rank, we studied the behaviours of 103 animals from eight captive colonies. We performed focal sampling and ran mixed-effects models to assess which factors explained variation in working behaviour during six ten-minute observation periods per individual.

Results: Contrary to widely-held beliefs, we found that working behaviour did not decrease linearly with weight, although polynomial regressions indicated younger and medium-sized individuals worked most frequently, while high-ranking individuals worked for the shortest periods of time. Working behaviour and its relationship with individual characteristics also varied between colonies.

Conclusions: While age- or size-based polyethisms may have some influence on working behaviour, we argue that other characteristics of the individual and colony are also important. In particular, the interactions of individual, social and environmental factors must be considered in order to understand the emergence and effectiveness of the division of labour that is so critical to many social organisms.
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http://dx.doi.org/10.7717/peerj.9891DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7531346PMC
September 2020

The novel use of the Haemodialysis reliable outflow graft (HeRo) in intestinal failure patients with end-stage vascular access.

J Vasc Access 2021 Nov 30;22(6):1021-1025. Epub 2020 Sep 30.

Oxford Transplant Centre, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK.

Intestinal failure (IF) patients are dependent on central venous access to receive parenteral nutrition. Longstanding central venous catheters are associated with life-threatening complications including infections and thromboses resulting in multiple line exchanges and the development ofprogressive central venous stenosis or occlusion. The Haemodialysis Reliable Outflow (HeRO) graft is an arterio-venous device that has been successfully used in haemodialysis patients with 'end-stage vascular access'. We describe a case series of HeRO graft use in patients with IF and end-stage vascular access. Four HeRO grafts were inserted into IF patients with end-stage vascular access to facilitate or support intestinal transplantation. In all patients the HeRO facilitated immediate vascular access, supporting different combinations of parenteral nutrition, intravenous medications, fluids or renal replacement therapy with no bloodstream infections. In a highly complex group of IF patients with central venous stenosis/occlusion limiting conventional venous access or at risk of life-threatening catheter-related complications, a HeRO graft can be a feasible alternative.
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http://dx.doi.org/10.1177/1129729820961972DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641026PMC
November 2021

Genome-wide CRISPR screens of oral squamous cell carcinoma reveal fitness genes in the Hippo pathway.

Elife 2020 09 29;9. Epub 2020 Sep 29.

Head and Neck Cancer Research Team, Cancer Research Malaysia, Head and Neck Cancer Research Team, Subang Jaya, Selangor, Malaysia.

New therapeutic targets for oral squamous cell carcinoma (OSCC) are urgently needed. We conducted genome-wide CRISPR-Cas9 screens in 21 OSCC cell lines, primarily derived from Asians, to identify genetic vulnerabilities that can be explored as therapeutic targets. We identify known and novel fitness genes and demonstrate that many previously identified OSCC-related cancer genes are non-essential and could have limited therapeutic value, while other fitness genes warrant further investigation for their potential as therapeutic targets. We validate a distinctive dependency on YAP1 and WWTR1 of the Hippo pathway, where the lost-of-fitness effect of one paralog can be compensated only in a subset of lines. We also discover that OSCCs with WWTR1 dependency signature are significantly associated with biomarkers of favorable response toward immunotherapy. In summary, we have delineated the genetic vulnerabilities of OSCC, enabling the prioritization of therapeutic targets for further exploration, including the targeting of YAP1 and WWTR1.
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http://dx.doi.org/10.7554/eLife.57761DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7591259PMC
September 2020

von Willebrand Factor Predicts Mortality in ACS Patients Treated with Potent P2Y12 Antagonists and is Inhibited by Aptamer BT200 Ex Vivo.

Thromb Haemost 2020 Sep 17;120(9):1282-1290. Epub 2020 Jul 17.

Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.

Background:  von Willebrand factor (VWF) is crucial for arterial thrombosis and its plasma levels are increased in acute coronary syndromes (ACSs). The effects of conventional platelet inhibitors are compromised by elevated VWF under high shear rates. BT200 is a third-generation aptamer that binds and inhibits the A1 domain of human VWF. This article aims to study whether VWF is a predictor of mortality in ACS patients under potent P2Y12 blocker therapy and to examine the effects of a VWF inhibiting aptamer BT200 and its concentrations required to inhibit VWF in plasma samples of patients with ACS.

Methods:  VWF activity was measured in 320 patients with ACS, and concentration effect curves of BT200 were established in plasma pools containing different VWF concentrations.

Results:  Median VWF activity in patients was 170% (interquartile range % confidence interval [CI]: 85-255) and 44% of patients had elevated (> 180%) VWF activity. Plasma levels of VWF activity predicted 1-year (hazard ratio [HR]: 2.68; 95% CI: 1.14-6.31;  < 0.024) and long-term (HR: 2.59; 95% CI: 1.10-6.09) mortality despite treatment with potent platelet inhibitors (dual-antiplatelet therapy with aspirin and prasugrel or ticagrelor). Although half-maximal concentrations were 0.1 to 0.2 µg/mL irrespective of baseline VWF levels, increasing concentrations (0.42-2.13 µg/mL) of BT200 were needed to lower VWF activity to < 20% of normal in plasma pools containing increasing VWF activity ( < 0.001).

Conclusion:  VWF is a predictor of all-cause mortality in ACS patients under contemporary potent P2Y12 inhibitor therapy. BT200 effectively inhibited VWF activity in a target concentration-dependent manner.
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http://dx.doi.org/10.1055/s-0040-1713888DOI Listing
September 2020

The aptamer BT200 effectively inhibits von Willebrand factor (VWF) dependent platelet function after stimulated VWF release by desmopressin or endotoxin.

Sci Rep 2020 07 7;10(1):11180. Epub 2020 Jul 7.

Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.

Von Willebrand factor (VWF) plays a major role in arterial thrombosis. Antiplatelet drugs induce only a moderate relative risk reduction after atherothrombosis, and their inhibitory effects are compromised under high shear rates when VWF levels are increased. Therefore, we investigated the ex vivo effects of a third-generation anti-VWF aptamer (BT200) before/after stimulated VWF release. We studied the concentration-effect curves BT200 had on VWF activity, platelet plug formation under high shear rates (PFA), and ristocetin-induced platelet aggregation (Multiplate) before and after desmopressin or endotoxin infusions in healthy volunteers. VWF levels increased > 2.5-fold after desmopressin or endotoxin infusion (p < 0.001) and both agents elevated circulating VWF activity. At baseline, 0.51 µg/ml BT200 reduced VWF activity to 20% of normal, but 2.5-fold higher BT200 levels were required after desmopressin administration (p < 0.001). Similarly, twofold higher BT200 concentrations were needed after endotoxin infusion compared to baseline (p < 0.011). BT200 levels of 0.49 µg/ml prolonged collagen-ADP closure times to > 300 s at baseline, whereas 1.35 µg/ml BT200 were needed 2 h after desmopressin infusion. Similarly, twofold higher BT200 concentrations were necessary to inhibit ristocetin induced aggregation after desmopressin infusion compared to baseline (p < 0.001). Both stimuli elevated plasma VWF levels in a manner representative of thrombotic or pro-inflammatory conditions such as arterial thrombosis. Even under these conditions, BT200 potently inhibited VWF activity and VWF-dependent platelet function, but higher BT200 concentrations were required for comparable effects relative to the unstimulated state.
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http://dx.doi.org/10.1038/s41598-020-68125-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341806PMC
July 2020

Hybridization Liquid Chromatography-Tandem Mass Spectrometry: An Alternative Bioanalytical Method for Antisense Oligonucleotide Quantitation in Plasma and Tissue Samples.

Anal Chem 2020 08 17;92(15):10548-10559. Epub 2020 Jul 17.

Drug Metabolism and Pharmacokinetics, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States.

Quantitative bioanalysis in plasma and tissues samples is required to study the pharmacokinetic and pharmacodynamic properties of antisense oligonucleotides (ASOs). To overcome intrinsic drawbacks in specificity, sensitivity, and throughput of traditional ligand-binding assay (LBA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods, an alternative bioanalytical method was developed by combining oligonucleotide hybridization and LC-MS/MS technologies. Target ASOs were extracted from biological samples by hybridization with biotinylated sense-strand oligonucleotides coupled to streptavidin magnetic beads. Using ion-pairing chromatography and tandem mass spectrometry, this method demonstrated high sensitivity (0.5 ng/mL using 100 μL of plasma), high specificity, wide linear range, complete automation, and generic applications in tests with multiple ASOs. The typical challenge of sensitivity drop in traditional ion-pairing LC-MS/MS was for the first time overcome by the introduction of a ternary pump system. Due to the high specificity, quantitation in various biological matrixes was achieved using calibration standards in plasma, largely improving efficiency and consistency. Another major advantage was the capability of simultaneous quantitation of ASO metabolites. The hybridization LC-MS/MS was considered an improved alternative for quantitation of ASOs and metabolites in plasma and tissue samples, showing a great potential to replace traditional LBA and LC-MS/MS methods.
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http://dx.doi.org/10.1021/acs.analchem.0c01382DOI Listing
August 2020

Molecular Design of a Highly Stable Single-Ion Conducting Polymer Gel Electrolyte.

ACS Appl Mater Interfaces 2020 Jul 29;12(26):29162-29172. Epub 2020 May 29.

Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States.

Single-ion conducting (SIC) polymer electrolytes with a high Li transference number () have shown the capability to enable enhanced battery performance and safety by avoiding liquid-electrolyte leakage and suppressing Li dendrite formation. However, issues of insufficient ionic conductivity, low electrochemical stability, and poor polymer/electrode interfacial contact have greatly hindered their commercial use. Here, a Li-containing boron-centered fluorinated SIC polymer gel electrolyte (LiBFSIE) was rationally designed to achieve a high and high electrochemical stability. Owing to the low dissociation energy of the boron-centered anion and Li, the as-prepared LiBFSIE exhibited an ionic conductivity of 2 × 10 S/cm at 35 °C, which is exclusively contributed by Li ions owing to a high of 0.93. Both simulation and experimental approaches were applied to investigate the ion diffusion and concentration gradient in the LiBFSIE and non-cross-linked dual-ion systems. Typical rectangular Li stripping/plating voltage profiles demonstrated the uniform Li deposition assisted by LiBFSIE. The interfacial contact and electrolyte infiltration were further optimized with an UV-vis-initiated polymerization method together with the electrode materials. By virtue of the high electrochemical stability of LiBFSIE, the cells achieved a promising average Coulombic efficiency of 99.95% over 200 cycles, which is higher than that of liquid-electrolyte-based cells. No obvious capacity fading was observed, indicating the long-term stability of LiBFSIE for lithium metal batteries.
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http://dx.doi.org/10.1021/acsami.0c03363DOI Listing
July 2020

Viral contamination in biologic manufacture and implications for emerging therapies.

Nat Biotechnol 2020 05 27;38(5):563-572. Epub 2020 Apr 27.

Novartis, Basel, Switzerland.

Recombinant protein therapeutics, vaccines, and plasma products have a long record of safety. However, the use of cell culture to produce recombinant proteins is still susceptible to contamination with viruses. These contaminations cost millions of dollars to recover from, can lead to patients not receiving therapies, and are very rare, which makes learning from past events difficult. A consortium of biotech companies, together with the Massachusetts Institute of Technology, has convened to collect data on these events. This industry-wide study provides insights into the most common viral contaminants, the source of those contaminants, the cell lines affected, corrective actions, as well as the impact of such events. These results have implications for the safe and effective production of not just current products, but also emerging cell and gene therapies which have shown much therapeutic promise.
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http://dx.doi.org/10.1038/s41587-020-0507-2DOI Listing
May 2020

Potent and rapid reversal of the von Willebrand factor inhibitor aptamer BT200.

J Thromb Haemost 2020 07 10;18(7):1695-1704. Epub 2020 Jun 10.

Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.

Background: BT200, a pegylated form of the aptamer BT100, inhibits binding of von Willebrand factor (VWF) to platelet glycoprotein GPIb, preventing arterial thrombosis in cynomolgus monkeys. It is being developed for secondary prevention of arterial thrombosis such as stroke or myocardial infarction. Inhibition of thrombogenesis by BT200 is expected to provide a therapeutic benefit. However, there may be unexpected bleeding (eg, incidental trauma) in which a reversal agent is required. To address this need, BT101, a complementary aptamer, has been developed to specifically inhibit BT100 and BT200 function.

Objectives: To characterize the effects of BT101 both in vitro and in vivo.

Methods: The direct interaction between BT101 and the core aptamer BT100 was evaluated using polyacrylamide gel electrophoresis. The binding of BT200 to purified human VWF and inhibition of VWF activity was further characterized using enzyme-linked immunosorbent assay. VWF-dependent platelet function was measured by the platelet function analyzer and aggregometry in whole blood. In addition, both the in vivo pharmacokinetic profile of BT101 as well as its ability to reverse BT200 activity, were evaluated in cynomolgus monkeys.

Results: BT101 bound to the core aptamer BT100 at a 1:1 ratio, inhibited BT200 binding to purified human VWF, and reversed BT200-induced inhibition of both VWF activity and VWF-dependent platelet function in vitro. After intravenous injection to monkeys, BT101 reversed BT200-induced effects on VWF activity and platelet function within minutes, without causing any adverse effects.

Conclusions: The results of this study demonstrate that BT101 is an effective reversal agent for BT200.
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http://dx.doi.org/10.1111/jth.14822DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7384040PMC
July 2020

Inhibition of complement C1s in patients with cold agglutinin disease: lessons learned from a named patient program.

Blood Adv 2020 03;4(6):997-1005

Division of Hematology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria.

Cold agglutinin disease (CAD) causes predominantly extravascular hemolysis and anemia via complement activation. Sutimlimab is a novel humanized monoclonal antibody directed against classical pathway complement factor C1s. We aimed to evaluate the safety and efficacy of long-term maintenance treatment with sutimlimab in patients with CAD. Seven CAD patients treated with sutimlimab as part of a phase 1B study were transitioned to a named patient program. After a loading dose, patients received biweekly (once every 2 weeks) infusions of sutimlimab at various doses. When a patient's laboratory data showed signs of breakthrough hemolysis, the dose of sutimlimab was increased. Three patients started with a dose of 45 mg/kg, another 3 with 60 mg/kg, and 1 with a fixed dose of 5.5 g every other week. All CAD patients responded to re-treatment, and sutimlimab increased hemoglobin from a median initial level of 7.7 g/dL to a median peak of 12.5 g/dL (P = .016). Patients maintained near normal hemoglobin levels except for a few breakthrough events that were related to underdosing and which resolved after the appropriate dose increase. Four of the patients included were eventually treated with a biweekly 5.5 g fixed-dose regimen of sutimlimab. None of them had any breakthrough hemolysis. All patients remained transfusion free while receiving sutimlimab. There were no treatment-related serious adverse events. Overlapping treatment with erythropoietin, rituximab, or ibrutinib in individual patients was safe and did not cause untoward drug interactions. Long-term maintenance treatment with sutimlimab was safe, effectively inhibited hemolysis, and significantly increased hemoglobin levels in re-exposed, previously transfusion-dependent CAD patients.
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http://dx.doi.org/10.1182/bloodadvances.2019001321DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094024PMC
March 2020

Single-centre experience of an early cannulation graft for haemodialysis access.

J Vasc Access 2020 Nov 6;21(6):883-891. Epub 2020 Mar 6.

Oxford Transplant Centre, Oxford University Hospitals NHS Foundation Trust, Churchill Hospital, Oxford, UK.

Introduction: As the demographics of the population changes, increasing challenges are being faced in providing reliable access for dialysis. This article reports on the outcomes from the largest series to date using the early cannulation graft Flixene in a single centre.

Methods: Between May 2012 and March 2018, 141 Flixene grafts were placed for dialysis access. The outcomes of the arteriovenous grafts were reviewed retrospectively from electronically held records and imaging.

Results: In 75 patients, placement of Flixene graft was performed on an emergency basis and in 66 patients on a planned elective list. The 12-month primary, assisted primary and secondary patency rates were 48.7%, 56.6% and 83.6%, respectively. Eight (5.7%) patients developed infections of the graft during the follow-up period.

Conclusion: In our experience, we have found the use of the early cannulation graft Flixene to be safe with a low complication rate and favourable patency rates. We believe these early cannulation grafts provide a useful addition for vascular access surgeons preventing the use of tunnelled lines and providing more flexibility in the timing of placing a graft for dialysis.
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http://dx.doi.org/10.1177/1129729820909026DOI Listing
November 2020

Integrated Hydrologic Modeling to Untangle the Impacts of Water Management During Drought.

Ground Water 2020 05 11;58(3):377-391. Epub 2020 Apr 11.

Hydrologic Science and Engineering Program, Integrated Groundwater Modeling Center, Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO, 80401, USA.

Over the past century, groundwater levels in California's San Joaquin Valley have dropped by more than 30 m in some areas mostly due to excessive groundwater extraction used to irrigate agricultural lands and sustain a growing population. Between 2012 and 2015, California experienced the worst drought in its recorded history, depleting surface water supplies and further exacerbating groundwater depletion in the region. Due to a lack of groundwater regulation, exact quantities of extracted groundwater in California are unknown and hard to quantify. Recent adoption of the Sustainable Groundwater Management Act has intensified efforts to identify sustainable groundwater use. However, understanding sustainable use in a highly productive agricultural system with an extremely complex surface water allocation system, variable groundwater use, and spatially extensive and diverse irrigation practices is no easy task. Using an integrated hydrologic model coupled with a land surface model, we evaluated how water management activities, specifically a suite of irrigation and groundwater pumping scenarios, impact surface water-groundwater fluxes and storage components and how those activities and the relationships between them change during drought. Results showed that groundwater pumping volume had the most significant impact on long-term water storage changes. A comparison with total water storage anomaly (TWSA) estimates from NASA's Gravity Recover and Climate Experiment (GRACE) provided some insight regarding which combinations of pumping and irrigation matched the GRACE TWSA estimates, lending credibility to these scenarios. In addition, the majority of long-term water storage changes during the recent drought occurred in groundwater storage in the deeper subsurface.
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http://dx.doi.org/10.1111/gwat.12995DOI Listing
May 2020

Rates of increase in gray seal () pupping at recolonized sites in the United States, 1988-2019.

J Mammal 2020 Feb 13;101(1):121-128. Epub 2019 Dec 13.

University of Maine, Department of Wildlife, Fisheries and Conservation Biology, Orono, ME, USA.

Gray seals were historically distributed along the northeastern coast of the United States, but bounties and lack of protection reduced numbers and they were rarely observed for most of the 20th century. Once protections were enacted, the population started to rebound. Here, we describe the recolonization and recovery of gray seals in the United States, focusing on the re-establishment of pupping sites. We fit individual generalized linear models to various time series (1988-2019) to estimate rates of increase in observed pup counts at four of the more data-rich sites. Annual rate of increase at individual sites ranged from -0.2% (95% : -2.3-1.9%) to 26.3% (95% : 21.6-31.4%). The increase in sites and number of pups born in the United States is driven by population growth and immigration from Canadian colonies and is part of a larger recovery of the Northwest Atlantic population. Wildlife protection, a healthy source population, habitat availability, and species traits that allow for dispersal and high productivity were all important factors in this recovery.
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http://dx.doi.org/10.1093/jmammal/gyz184DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035213PMC
February 2020

The development and characterization of a long acting anti-thrombotic von Willebrand factor (VWF) aptamer.

J Thromb Haemost 2020 05 5;18(5):1113-1123. Epub 2020 Mar 5.

Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.

Background: Thrombus formation involves coagulation proteins and platelets. The latter, referred to as platelet-mediated thrombogenesis, is predominant in arterial circulation. Platelet thrombogenesis follows vascular injury when extracellular von Willebrand factor (VWF) binds via its A3 domain to exposed collagen, and the free VWF A1 domain binds to platelet glycoprotein Ib (GPIb).

Objectives: To characterize the antiplatelet/antithrombotic activity of the pegylated VWF antagonist aptamer BT200 and identify the aptamer VWF binding site.

Methods: BT100 is an optimized aptamer synthesized by solid-phase chemistry and pegylated (BT200) by standard conjugation chemistry. The affinity of BT200 for purified human VWF was evaluated as was VWF inhibition in monkey and human plasma. Efficacy of BT200 was assessed in the monkey FeCl femoral artery thrombosis model.

Results: BT200 bound human VWF at an EC of 5.0 nmol/L and inhibited VWF A1 domain activity in monkey and human plasma with mean IC values of 183 and 70 nmol/L. BT200 administration to cynomolgus monkeys caused a time-dependent and dose-dependent effect on VWF A1 domain activity and inhibited platelet function as measured by collagen adenosine diphosphate closure time in the platelet function analyzer. BT200 demonstrated a bioavailability of ≥77% and exhibited a half-life of >100 hours after subcutaneous injection. The treatment effectively prevented arterial occlusion in an FeCl -induced thrombosis model in monkeys.

Conclusions: BT200 has shown promising inhibition of human VWF in vitro and prevented arterial occlusion in non-human primates. These data including a long half-life after subcutaneous injections provide a strong rationale for ongoing clinical development of BT200.
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http://dx.doi.org/10.1111/jth.14755DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7317574PMC
May 2020

Thyroid disease assessment and management: summary of NICE guidance.

BMJ 2020 01 29;368:m41. Epub 2020 Jan 29.

University of Birmingham, Birmingham, UK.

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http://dx.doi.org/10.1136/bmj.m41DOI Listing
January 2020

An analysis of the association between older recipient age and outcomes after whole-organ pancreas transplantation - a single-centre, retrospective study.

Transpl Int 2020 05 7;33(5):529-535. Epub 2020 Feb 7.

Oxford Transplant Centre, Oxford, UK.

Older people are increasingly being referred for consideration for pancreas transplantation (PT). We investigated the outcomes after PT in our older recipient cohort. A prospectively maintained database was interrogated. The cohort was analysed for associations between outcome and older recipient age. A total of 444 transplants were performed in patients aged 23-54 years and 83 transplants in patients aged 55-67 years. There was no difference in death-censored pancreas or kidney graft survival between the groups. Patient death was associated with older recipient age (HR 1.63 per 10-year increase). In multivariate Cox regression, risk of mortality was also associated with post-transplant myocardial infarction (HR 7.25, P = 0.006), pancreas failure (HR 1.91, P = 0.003) and kidney failure (HR 3.55, P < 0.001). About 40% of recipients who died in the first year post-transplant suffered early graft loss. Those alive at a year post-transplant had inferior survival if they had lost their kidney graft (P < 0.001). Mortality is higher in older patients and is strongly associated with pancreas and kidney graft failure. This suggests that pancreas transplantation is feasible in older recipients, and careful selection of donor organs is important to optimize survival.
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http://dx.doi.org/10.1111/tri.13575DOI Listing
May 2020

Increased expression of schizophrenia-associated gene C4 leads to hypoconnectivity of prefrontal cortex and reduced social interaction.

PLoS Biol 2020 01 14;18(1):e3000604. Epub 2020 Jan 14.

Department of Biology, Boston University, Boston, Massachusetts, United States of America.

Schizophrenia is a severe mental disorder with an unclear pathophysiology. Increased expression of the immune gene C4 has been linked to a greater risk of developing schizophrenia; however, it is not known whether C4 plays a causative role in this brain disorder. Using confocal imaging and whole-cell electrophysiology, we demonstrate that overexpression of C4 in mouse prefrontal cortex neurons leads to perturbations in dendritic spine development and hypoconnectivity, which mirror neuropathologies found in schizophrenia patients. We find evidence that microglia-mediated synaptic engulfment is enhanced with increased expression of C4. We also show that C4-dependent circuit dysfunction in the frontal cortex leads to decreased social interactions in juvenile and adult mice. These results demonstrate that increased expression of the schizophrenia-associated gene C4 causes aberrant circuit wiring in the developing prefrontal cortex and leads to deficits in juvenile and adult social behavior, suggesting that altered C4 expression contributes directly to schizophrenia pathogenesis.
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http://dx.doi.org/10.1371/journal.pbio.3000604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6959572PMC
January 2020

A Novel Inside-out Access Approach for Hemodialysis Catheter Placement in Patients With Thoracic Central Venous Occlusion.

Am J Kidney Dis 2020 04 29;75(4):480-487. Epub 2019 Nov 29.

Department of Nephrology, Medical University of Vienna, Vienna, Austria.

Rationale & Objective: Left-sided internal jugular and all subclavian central venous catheters (CVCs) cause thoracic central vein occlusions (TCVOs) more often than right-sided internal jugular catheters. To enable right-sided CVC placement in patients with TCVO, an inside-out access (IOA) approach was established at 3 vascular access centers in Europe involving use of a novel IOA device advanced from the right femoral vein. In the current analysis, we assessed the eligibility and success rate of this IOA approach in a cohort of patients with TCVO requiring a tunneled dialysis catheter.

Study Design: Retrospective multicenter observational study.

Setting & Participants: 36 patients with TCVO treated in Vienna, Austria; Oxford, England; or Cologne, Germany, who required hemodialysis access between July 2016 and June 2018.

Exposure: Application of the IOA approach to gain vascular access.

Outcome: The primary end point was the success rate of passing the TCVO to gain dialysis access using the IOA approach. Secondary end points were catheter patency at 3 months and procedure-related complications (early infections, bleeding, hematoma, and pericardial effusions).

Analytical Approach: Descriptive statistics to characterize eligibility, success rate, and complications of the IOA approach.

Results: 36 patients with TCVO and history of multiple CVCs and arteriovenous fistulas were referred to the participating centers for vascular access. 32 (89%) patients were eligible for the IOA approach. 39 treatments were performed, with 7 patients undergoing the IOA procedure a second time more than 3 months after initial CVC placement. Dialysis access was established successfully in 38 of 39 (97%) implementations of the IOA procedure. Median intervention time was 43 minutes. No complications occurred.

Limitations: No comparison to other methods to place CVCs and the observational study design.

Conclusions: The IOA approach is a promising method to enable rapid access to the right jugular vein in the setting of pre-existing TCVO. Additional experience is needed to understand the generalizability of these observations.
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http://dx.doi.org/10.1053/j.ajkd.2019.08.024DOI Listing
April 2020
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