Efficacy and Safety of Lerodalcibep in Patients With or at High Risk of Cardiovascular Disease: A Randomized Clinical Trial.

Importance: Recent changes in national and international lipid guidelines for reducing cardiovascular events recommend additional drugs, greater reductions, and lower targets for low-density lipoprotein cholesterol (LDL-C) if not attained with statins. The achievement of these targets with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has not yet been evaluated in a randomized clinical trial. Objective: To evaluate the 52-week safety and efficacy of lerodalcibep, a small anti-PCSK9-binding protein, in patients with cardiovascular disease (CVD) or who are at very high or high risk of CVD and requiring addition LDL-C-lowering treatment. Design, Setting, and Participants: This was a randomized, double-blind, placebo-controlled phase 3 trial. The trial was conducted at 66 clinics in 11 countries between April 23, 2021, and November 15, 2023. Individuals 18 years and older taking maximally tolerated statin therapy with LDL-C of 70 mg/dL or greater with CVD or 100 mg/dL or greater if at high risk of CVD were included. Interventions: Patients were randomized 2:1 to monthly 1.2-mL subcutaneous lerodalcibep, 300 mg, or placebo for 52 weeks. Main Outcomes and Measures: The safety analysis included all randomized patients. The co-primary efficacy end points were percent change from baseline in LDL-C at week 52 and the mean of weeks 50 and 52. Secondary efficacy outcomes included additional lipid apolipoprotein measures and achievement of guideline-recommended LDL-C targets. Results: Of 922 randomized participants (mean [range] age, 64.5 [27-87] years; 414 [44.9%] female; mean [SD] baseline LDL-C, 116.2 [43.5] mg/dL), 811 (88%) completed the trial. The mean (SE) placebo-adjusted reduction in LDL-C with lerodalcibep by modified intention-to-treat (mITT) analysis was 56.2% (2.2%) at week 52 and 62.7% (1.9%) for the mean of weeks 50 and 52; 49.7% (2.4%) and 55.3% (2.2%) by ITT with imputation using a washout model, and 60.3% (2.3%) and 65.9% (1.9%) by per-protocol analysis at week 52 and the mean of weeks 50 and 52, respectively (P < .001 for all). With lerodalcibep, 555 of 615 participants (90%) achieved both a reduction in LDL-C of 50% or greater and recommended LDL-C targets during the study. Treatment-emergent adverse events were similar between lerodalcibep and placebo, except for injection site reactions. These occurred in 42 of 613 participants receiving lerodalcibep (6.9%) compared to 1 of 307 receiving placebo (0.3%), were graded mild or moderate, and did not result in higher discontinuation of treatment, at 26 of 613 (4.2%) and 14 of 307 (4.6%), respectively. Sporadic in vitro antidrug antibodies were detected, which had no impact on free PCSK9 or LDL-C-lowering efficacy. Conclusions and Relevance: In this trial, lerodalcibep, a novel anti-PCSK9 small binding protein, dosed monthly and stable at ambient temperatures significantly reduced LDL-C in patients with CVD or at high risk of atherosclerotic cardiovascular disease with a safety profile similar to placebo. These results support long-term use of lerodalcibep in patients with CVD or at high risk of CVD who are unable to achieve adequate LDL-C reduction while receiving maximal tolerated statins alone. Trial Registration: ClinicalTrials.gov Identifier: NCT04806893.

Intact natalizumab pharmacokinetics is impacted by endogenous IgG4 concentration.

BACKGROUND: Natalizumab (NAT) pharmacokinetics and pharmacodynamics are complicated by arm exchange with endogenous IgG4, resulting in a mixture of a more potent intact, bivalent form and a less potent, functionally monovalent form. Total NAT and endogenous IgG4 concentrations vary considerably across patients. This study assessed the concentration of intact NAT, and how it relates to total NAT and endogenous IgG4 levels in blood and saliva. METHODS: Paired serum and saliva samples from a small cohort of relapsing-remitting multiple sclerosis patients were measured for levels of intact NAT, total NAT, IgG and IgG4. RESULTS: Intact NAT concentration was dependent on both total NAT and endogenous IgG4 levels. Low endogenous IgG4 led to a higher ratio of intact NAT to total NAT, while the opposite was observed in subjects with high endogenous IgG4. Serum and saliva measurements show good concordance. CONCLUSIONS: Intact NAT concentration is influenced by both NAT pharmacokinetics and endogenous IgG4 levels. Patients with low IgG4 levels can have high concentrations of intact NAT even with lower levels of total NAT, which may explain cases of NAT-associated progressive multifocal leukoencephalopathy (PML) in such patients. Monitoring both forms of NAT could better guide dosing, maximizing drug efficacy and safety.

COVID-19 Pandemic on COPD Healthcare Utilization, Exacerbations and Mortality: A Population Study.

RATIONALE: Existing work suggests that patients with COPD (pwCOPD) presented less frequently to the emergency department (ED) and were less likely to be hospitalized during the COVID-19 pandemic but it is unclear if this was due to improved health and disease management or to increased barriers/avoidance of healthcare. The objective of this study is to determine the impact of the pandemic on inpatient and outpatient healthcare utilization, disease incidence, and mortality rates in pwCOPD. METHODS: A retrospective population-based analysis using linked administrative datasets from Alberta, Canada18 months before and after March 12, 2020 was conducted to measure hospitalization, ED and outpatient visits, and COPD outpatient exacerbations during these time periods. Mortality data was also analyzed pre- versus post-pandemic, taking confirmed COVID-19 infection within 30 days into account. Subgroup analysis based on COPD exacerbation risk stratification was undertaken to determine if healthcare utilization differed based on exacerbation risk. Finally, sex-based analysis of healthcare utilization during the pandemic was also completed. RESULTS: Hospitalization/ED visits and outpatient treatment for acute exacerbations of COPD dropped while total outpatient COPD visits, including both virtual and in-person, increased during the pandemic for pwCOPD. Mortality rate increased even after adjusting for COVID-19-associated deaths. Sex-based subgroup analysis showed a greater drop in acute care utilization for females but the rise in mortality was seen for both sexes with men experiencing greater rate of mortality than women. CONCLUSIONS: Overall pwCOPD accessed acute care resources less during the pandemic which may have contributed to a rise in non-COVID all-cause mortality.

Mental health services in Gauteng, South Africa: A proxy evaluation using pharmaceutical data.

Background: South African legislation advocates for equitable access to mental healthcare services integrated into general healthcare settings. Mental, neurological, and substance use (MNS) disorders are often comorbid. Pharmacoepidemiology provides indirect evidence of service provision for conditions amenable to medicine treatment. Aim: The study aims to evaluate medicine procurement for MNS disorders at different service levels in the health system. Setting: The Public health sector, Gauteng province formed the setting for the study. Method: A secondary analysis of the Gauteng pharmaceutical database was conducted using Anatomic Therapeutic Chemical (ATC) and defined daily dose (DDD) methodology. Anatomic Therapeutic Chemical classes of medicines for MNS disorders were included. Defined daily doses and costs were calculated per 1000 population served by each facility and service level. Statistical comparisons were made using chi-square testing. Results: General healthcare settings accounted for 90% (R118 638 248) and specialised hospitals for 10% (R13 685 032) of expenditure on medicines for MNS disorders, procuring 94% (n = 49 442 474) and 6% (n = 3 311 528) of DDDs, respectively. Although district clinics procured 60% of DDDs, they procured the least per 1000 population served, whereas district hospitals procured the most. For almost all ATC classes, procurement differed significantly between municipalities at every service level and between specialised hospitals. Conclusion: In Gauteng province, most medicines for MNS disorders are procured by general healthcare services, but access to care may not be equitable. While population coverage at district clinics appears low, district hospitals may experience the greatest care burden. Research regarding quality of care at each service level is recommended. Contribution: This study provides insight into service provision for MNS disorders.

Comparison of preoperative retrobulbar bupivacaine and postoperative subcutaneous liposome-encapsulated bupivacaine on postoperative analgesia in dogs undergoing enucleation.

OBJECTIVE: To compare the effectiveness of preoperative bupivacaine inferotemporal retrobulbar blocks to postoperative liposome-encapsulated bupivacaine (Nocita) line blocks for analgesia following enucleation. ANIMALS: 39 client-owned dogs (40 eyes) presenting to the Ophthalmology Service for enucleation. METHODS: Dogs were randomly assigned to receive either a preoperative inferotemporal retrobulbar block with 0.5% bupivacaine or a peri-incisional line block with liposome-encapsulated bupivacaine (Nocita) at closure. Patients underwent unilateral enucleation and were hospitalized for 24 hours after surgery. Pain scores were performed by a masked observer with the Glasgow Composite Measure Pain Scale and the University of Wisconsin Ocular Pain Scale at 0.25, 0.5, 1, 2, 4, 6, 8, and 24 hours following surgery. Intraoperative use of blood pressure and anesthetic support mediations as well as need for rescue pain control were recorded and compared between groups. RESULTS: There was no significant difference in rescue rates between treatment groups. When comparing the use of medical intraoperative heart rate, blood pressure, or anesthetic plane support, there were no significant differences in use between groups. CLINICAL RELEVANCE: Use of preoperative bupivacaine retrobulbar blocks and postoperative Nocita line blocks were equally effective at postoperative pain control with similarly low complication rates.

Tracheostomy and long-term invasive ventilation decision-making in children: A scoping review.

An increasing number of children are surviving critical illnesses requiring tracheostomy/long-term ventilation (LTV). This scoping review seeks to collate the available evidence on decision-making for tracheostomy/LTV in children. Systematic searches of electronic databases and websites were conducted for articles and reports. Inclusion criteria included: (1) children 0-18 years old; (2) described use of tracheostomy or tracheostomy/LTV; and (3) information on recommendations for tracheostomy decision-making or decision-making experiences of family-caregivers or health care providers. Articles not written in English were excluded. Of the 4463 records identified through database search and other methods, a total of 84 articles, 2 dissertations, 1 book chapter, 3 consensus statement/society guidelines, and 8 pieces of grey literature were included. Main thematic domains identified were: (1) legal and moral standards for decision-making; (2) decision-making models, roles of decision-makers, and decisional aids towards a shared decision-making model; (3) experiences and perspectives of decision-makers; (4) health system and society considerations; and (5) conflict resolution and legal considerations. A high degree of uncertainty and complexity is involved in tracheostomy/LTV decision-making. There is a need for a standardized decision-support process that is consistent with a child's best interests and shared decision-making. Strategies for optimizing communication and mechanism for managing disputes are needed.

Vesiculation in irradiated and cation-leaky-stored red blood cells.

BACKGROUND: Extracellular vesicles (EVs) are released by red blood cells (RBCs) throughout their life-span and also during hypothermic storage when they accumulate in the blood bag. We queried whether stored RBCs with increased cation permeability, either from donors with familial pseudohyperkalaemia (FP) or caused by irradiation, vesiculate more readily. STUDY DESIGN AND METHODS: Recent technical advances have revealed at least two sub-populations of MVs in RBC storage units: macrovesicles (2-6 µm) and microvesicles (1-2 µm). Using nanoparticle tracking analysis, imaging flow cytometry, and protein quantification methods, we measured and characterized vesicles released by RBCs from control and FP individuals at three different storage time-points (day 4, day 17, and day 29). The RBCs had either been stored untreated or irradiated on either day 1 or day 14 of storage. RESULTS: We found no difference in the number or size of vesicles released between cation-leaky FP RBCs and non-FP controls. Similarly, irradiated and non-irradiated RBCs showed very similar patterns of vesicle release to during cold-storage. The only significant difference in vesicle release was the increase in accumulated vesicles with length of storage time which has been reported previously. DISCUSSION: EVs in stored blood are potential contributors to adverse transfusion reactions. The number of vesicles released during 35-day hypothermic storage varies between donors and increases with storage duration. However, increased cation permeability and irradiation do not appear to affect vesicle formation during RBC cold-storage.

Mental health services in Gauteng, South Africa: A proxy evaluation using pharmaceutical data

Background: South African legislation advocates for equitable access to mental healthcare services integrated into general healthcare settings. Mental, neurological, and substance use (MNS) disorders are often comorbid. Pharmacoepidemiology provides indirect evidence of service provision for conditions amenable to medicine treatment. Aim: The study aims to evaluate medicine procurement for MNS disorders at different service levels in the health system. Setting: The Public health sector, Gauteng province formed the setting for the study. Method: A secondary analysis of the Gauteng pharmaceutical database was conducted using Anatomic Therapeutic Chemical (ATC) and defined daily dose (DDD) methodology. Anatomic Therapeutic Chemical classes of medicines for MNS disorders were included. Defined daily doses and costs were calculated per 1000 population served by each facility and service level. Statistical comparisons were made using chi-square testing. Results: General healthcare settings accounted for 90% (R118 638 248) and specialised hospitals for 10% (R13 685 032) of expenditure on medicines for MNS disorders, procuring 94% (n = 49 442 474) and 6% (n = 3 311 528) of DDDs, respectively. Although district clinics procured 60% of DDDs, they procured the least per 1000 population served, whereas district hospitals procured the most. For almost all ATC classes, procurement differed significantly between municipalities at every service level and between specialised hospitals. Conclusion: In Gauteng province, most medicines for MNS disorders are procured by general healthcare services, but access to care may not be equitable. While population coverage at district clinics appears low, district hospitals may experience the greatest care burden. Research regarding quality of care at each service level is recommended. Contribution: This study provides insight into service provision for MNS disorders.

Genetic dissection of regulation by a repressing and novel activating corrinoid riboswitch enables engineering of synthetic riboswitches.

IMPORTANCE: In addition to proteins, microbes can use structured RNAs such as riboswitches for the important task of regulating gene expression. Riboswitches control gene expression by changing their structure in response to binding a small molecule and are widespread among bacteria. Here we determine the mechanism of regulation in a riboswitch that responds to corrinoids-a family of coenzymes related to vitamin B12. We report the alternative RNA secondary structures that couple corrinoid sensing with response in a repressing and novel activating corrinoid riboswitch. We then applied this knowledge to flipping the regulatory sign by constructing synthetic riboswitches that activate expression to a higher level than the natural one. In the process, we observed patterns in which sequence, in addition to structure, impacts function in paired RNA regions. The synthetic riboswitches we describe here have potential applications as biosensors.

Unlocking the symmetric transfer of irrelevant information: gene-environment interplay and enhanced interhemispheric cross-talk.

Hemispheric specialization influences stimulus processing and behavioural control, affecting responses to relevant stimuli. However, most sensory input is irrelevant and must be filtered out to prevent interference with task-relevant behaviour, a process known as habituation. Despite habituation's vital role, little is known about hemispheric specialization for this brain function. We conducted an experiment with domestic chicks, an elite animal model to study lateralization. They were exposed to distracting visual stimuli while feeding when using binocular or monocular vision. Switching the viewing eye after habituation, we examined if habituation was confined to the stimulated hemisphere or shared across hemispheres. We found that both hemispheres learned equally to ignore distracting stimuli. However, embryonic light stimulation, influencing hemispheric specialization, revealed an asymmetry in interhemispheric transfer of the irrelevant information discarded via habituation. Unstimulated chicks exhibited a directional bias, with the right hemisphere failing to transfer distracting stimulus information to the left hemisphere, while transfer from left to right was possible. Nevertheless, embryonic light stimulation counteracted this asymmetry, enhancing communication from the right to the left hemisphere and reducing the pre-existing imbalance. This sharing extends beyond hemisphere-specific functions and encompasses a broader representation of irrelevant events.

Longer-Term Efficacy and Safety of Evinacumab in Patients With Refractory Hypercholesterolemia.

Importance: Patients with refractory hypercholesterolemia who do not achieve their guideline-defined low-density lipoprotein cholesterol (LDL-C) thresholds despite treatment with maximally tolerated combinations of lipid-lowering therapies (LLTs) have an increased risk of atherosclerotic cardiovascular disease (ASCVD). Objective: To evaluate longer-term efficacy and safety of evinacumab in patients with refractory hypercholesterolemia. Design, Setting, and Participants: This randomized clinical trial included a 2-week screening period followed by a 16-week double-blind treatment period (DBTP) for subcutaneous regimens (evinacumab, 450 mg, once weekly [QW]; evinacumab, 300 mg, QW; evinacumab, 300 mg, every 2 weeks; or placebo QW) or a 24-week DBTP for intravenous regimens (evinacumab, 15 mg/kg, every 4 weeks [Q4W]; evinacumab, 5 mg/kg, Q4W; or placebo Q4W); a 48-week open-label treatment period (OLTP) for intravenous treatment only; and a 24-week follow-up period. Patients from 85 sites across 20 countries were recruited for the study; patients with primary hypercholesterolemia (defined as heterozygous familial hypercholesterolemia or established clinical ASCVD without familial hypercholesterolemia) who entered the 48-week OLTP were included. In addition, the patients' hypercholesterolemia was refractory to maximally tolerated LLTs. Interventions: All patients entering the OLTP received evinacumab, 15 mg/kg, intravenously Q4W. Main Outcomes and Measures: Efficacy outcomes included change in LDL-C level and other lipid/lipoprotein parameters from baseline to week 72 (end of the OLTP). Safety outcomes included assessment of treatment-emergent adverse events (TEAEs). Results: A total of 96 patients (mean [SD] age, 54.4 [11.3] years; 52 female [54.2%]) entered the OLTP, of whom 88 (91.7%) completed the OLTP. Mean (SD) baseline LDL-C level was 145.9 (55.2) mg/dL. At week 72, evinacumab, 15 mg/kg, reduced mean (SD) LDL-C level from baseline by 45.5% (28.7%) in the overall cohort. Evinacumab, 15 mg/kg, reduced mean (SD) apolipoprotein B (38.0% [22.1%]), non-high density lipoprotein cholesterol (48.4% [23.2%]), total cholesterol (42.6% [17.5%]), and median (IQR) fasting triglyceride (57.2% [65.4%-44.4%]) levels at week 72 from baseline in the overall cohort. TEAEs occurred in 78 of 96 patients (81.3%). Serious TEAEs occurred in 9 of 96 patients (9.4%); all were considered unrelated to study treatment. Conclusions and Relevance: In patients with refractory hypercholesterolemia, evinacumab provided sustained reductions in LDL-C level and was generally well tolerated. Trial Registration: ClinicalTrials.gov Identifier: NCT03175367.

Knowledge of lateralized brain function can contribute to animal welfare.

The specialized functions of each hemisphere of the vertebrate brain are summarized together with the current evidence of lateralized behavior in farm and companion animals, as shown by the eye or ear used to attend and respond to stimuli. Forelimb preference is another manifestation of hemispheric lateralization, as shown by differences in behavior between left- and right-handed primates, left- and right-pawed dogs and cats, and left- and right-limb-preferring horses. Left-limb preference reflects right hemisphere use and is associated with negative cognitive bias. Positive cognitive bias is associated with right-limb and left-hemisphere preferences. The strength of lateralization is also associated with behavior. Animals with weak lateralization of the brain are unable to attend to more than one task at a time, and they are more easily stressed than animals with strong lateralization. This difference is also found in domesticated species with strong vs. weak limb preferences. Individuals with left-limb or ambilateral preference have a bias to express functions of the right hemisphere, heightened fear and aggression, and greater susceptibility to stress. Recognition of lateralized behavior can lead to improved welfare by detecting those animals most likely to suffer fear and distress and by indicating housing conditions and handling procedures that cause stress.

Genetic dissection of regulation by a repressing and novel activating corrinoid riboswitch enables engineering of synthetic riboswitches.

The ability to sense and respond to intracellular metabolite levels enables cells to adapt to environmental conditions. Many prokaryotes use riboswitches - structured RNA elements usually located in the 5' untranslated region of mRNAs - to sense intracellular metabolites and respond by modulating gene expression. The corrinoid riboswitch class, which responds to adenosylcobalamin (coenzyme B12) and related metabolites, is among the most widespread in bacteria. The structural elements for corrinoid binding and the requirement for a kissing loop interaction between the aptamer and expression platform domains have been established for several corrinoid riboswitches. However, the conformational changes in the expression platform that modulate gene expression in response to corrinoid binding remain unknown. Here, we employ an in vivo GFP reporter system in Bacillus subtilis to define alternative secondary structures in the expression platform of a corrinoid riboswitch from Priestia megaterium by disrupting and restoring base-pairing interactions. Moreover, we report the discovery and characterization of the first riboswitch known to activate gene expression in response to corrinoids. In both cases, mutually exclusive RNA secondary structures are responsible for promoting or preventing the formation of an intrinsic transcription terminator in response to the corrinoid binding state of the aptamer domain. Knowledge of these regulatory mechanisms allowed us to develop synthetic corrinoid riboswitches that convert repressing riboswitches to riboswitches that robustly induce gene expression in response to corrinoids. Due to their high expression levels, low background, and over 100-fold level of induction, these synthetic riboswitches have potential use as biosensors or genetic tools.

Understanding a constellation of eight COVID-19 disease prevention behaviours using the COM-B model and the theoretical domains framework: a qualitative study using the behaviour change wheel.

Background: The use of behavioural science and behaviour change within local authorities and public health has supported healthful change; as evidenced by its importance and contribution to reducing harm during the COVID-19 pandemic. It can provide valuable information to enable the creation of evidence-based intervention strategies, co-created with the people they are aimed at, in an effective and efficient manner. Aim: This study aimed to use the COM-B model to understand the Capability, Opportunity and Motivation of performing a constellation of eight COVID-19 disease prevention behaviours related to the slogans of 'Hands, Face, Space, Fresh Air'; 'Find, Isolate, Test, (FIT), and Vaccinate' in those employed in workplaces identified as high risk for transmission of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) to support intervention development. Methods: This qualitative study recruited twenty-three participants (16 female, 7 male), who were interviewed from three environments (schools, care homes, warehouses) across three local authorities. Semi-structured interviews were analysed using thematic analysis. Findings: Ten core themes were identified inductively; (1) knowledge and skills, (2) regulating the behaviour, (3) willingness to act, (4) necessity and concerns, (5) emotional impact, (6) conducive environment, (7) societal influence, (8) no longer united against COVID-19, (9) credible leadership, and (10) inconsistent adherence to COVID-19 prevention behaviours. Themes were then deductively mapped to the COM-B model of behaviour change and the theoretical domains framework and a logic model using the behaviour change wheel (BCW) was produced to inform intervention design. Conclusion: This study offers a novel approach to analysis that has included eight behaviours within a single thematic analysis and COM-B diagnosis. This will enable local authorities to direct limited resources to overarching priorities. Of key importance, was the need for supportive and credible leadership, alongside developing interventions collaboratively with the target audience. COVID-19 has had an emotional toll on those interviewed, however, promoting the value of disease prevention behaviours, over and above their costs, can facilitate behaviour. Developing knowledge and skills, through education, training, marketing and modelling can further facilitate behaviour. This supports guidance produced by the British Psychological Society COVID-19 behavioural science and disease prevention taskforce.

The Effectiveness of Liposome-Encapsulated Bupivacaine Compared to Standard Bupivacaine for Anesthesia of the Maxilla in Dogs.

Medical and surgical procedures involving the canine maxilla can be painful both during and for several hours post-procedure. The length of this pain may exceed the predicted duration of standard bupivacaine or lidocaine. The goal of this study was to determine the duration and efficacy of sensory blockade of the maxilla produced by liposome-encapsulated bupivacaine (LB), compared to standard bupivacaine (B) or saline (0.9% NaCl) (S), when administered as a modified maxillary nerve block in dogs. Eight maxillae were studied bilaterally from 4 healthy dogs of the same breed and similar age. This prospective, randomized, crossover, blinded study evaluated a modified maxillary nerve block using 1.3% LB at 0.1 mL/kg, 0.5% B, or S at an equivalent volume. An electronic von Frey aesthesiometer (VFA) was used to evaluate mechanical nociceptive thresholds at 4 locations on each hemimaxilla at baseline and at specific intervals up to 72-h post-treatment. Both B and LB treatments resulted in significantly higher VFA thresholds when compared to S. Dogs that received B had VFA thresholds significantly higher than S for 5 to 6 h. Dogs that received LB had thresholds significantly higher than S for 6 to 12 h depending on the site of measurement. No complications were observed. Maxillary nerve block with B provided up to 6 h, and LB 12 h, of sensory blockade depending on the site tested.

Accurate prediction of serum antibody levels from noninvasive saliva/nasal samples.

The importance of easily accessible, noninvasive samples, such as saliva, to effectively monitor serum antibody levels has been underscored by the SARS-CoV-2 (COVID-19) pandemic. Although a correlation between saliva and serum antibody titers has been observed, the ability to predict serum antibody levels from measurements in saliva is not well established. Herein, the authors demonstrate that measurements of SARS-CoV-2 antibody levels in both saliva and nasal specimens can be used to accurately determine serum levels by utilizing endogenous total IgG as an internal calibrator. They postulate that this method can be extended to the measurement of many different antibody analytes, making it of high interest for antibody therapeutic drug monitoring applications.

Structure and function of Plasmodium actin II in the parasite mosquito stages.

Actins are filament-forming, highly-conserved proteins in eukaryotes. They are involved in essential processes in the cytoplasm and also have nuclear functions. Malaria parasites (Plasmodium spp.) have two actin isoforms that differ from each other and from canonical actins in structure and filament-forming properties. Actin I has an essential role in motility and is fairly well characterized. The structure and function of actin II are not as well understood, but mutational analyses have revealed two essential functions in male gametogenesis and in the oocyst. Here, we present expression analysis, high-resolution filament structures, and biochemical characterization of Plasmodium actin II. We confirm expression in male gametocytes and zygotes and show that actin II is associated with the nucleus in both stages in filament-like structures. Unlike actin I, actin II readily forms long filaments in vitro, and near-atomic structures in the presence or absence of jasplakinolide reveal very similar structures. Small but significant differences compared to other actins in the openness and twist, the active site, the D-loop, and the plug region contribute to filament stability. The function of actin II was investigated through mutational analysis, suggesting that long and stable filaments are necessary for male gametogenesis, while a second function in the oocyst stage also requires fine-tuned regulation by methylation of histidine 73. Actin II polymerizes via the classical nucleation-elongation mechanism and has a critical concentration of ~0.1 µM at the steady-state, like actin I and canonical actins. Similarly to actin I, dimers are a stable form of actin II at equilibrium.

Nano-liter perfusion microfluidic device made entirely by two-photon polymerization for dynamic cell culture with easy cell recovery.

Polydimethylsiloxane (PDMS) has been the material of choice for microfluidic applications in cell biology for many years, with recent advances encompassing nano-scaffolds and surface modifications to enhance cell-surface interactions at nano-scale. However, PDMS has not previously been amenable to applications which require complex geometries in three dimensions for cell culture device fabrication in the absence of additional components. Further, PDMS microfluidic devices have limited capacity for cell retrieval following culture without severely compromising cell health. This study presents a designed and entirely 3D-printed microfluidic chip (8.8 mm × 8.2 mm × 3.6 mm) using two-photon polymerization (2PP). The 'nest' chip is composed of ten channels that deliver sub-microliter volume flowrates (to ~ 600 nL/min per channel) to 10 individual retrievable cell sample 'cradles' that interlock with the nest to create the microfluidic device. Computational fluid dynamics modelling predicted medium flow in the device, which was accurately validated by real-time microbead tracking. Functional capability of the device was assessed, and demonstrated the capability to deliver culture medium, dyes, and biological molecules to support cell growth, staining and cell phenotype changes, respectively. Therefore, 2PP 3D-printing provides the precision needed for nanoliter fluidic devices constructed from multiple interlocking parts for cell culture application.

Peptide Mimotope-Enabled Quantification of Natalizumab Arm Exchange During Multiple Sclerosis Treatment.

BACKGROUND: Natalizumab, a therapeutic antibody used to treat multiple sclerosis, undergoes in vivo Fab arm exchange to form a monovalent bispecific antibody. Although highly efficacious, the immunosuppressive activity of natalizumab has been associated with JC polyomavirus-driven progressive multifocal leukoencephalopathy (PML). Development of assays that can distinguish between and quantify bivalent (unexchanged) and monovalent (exchanged) forms of natalizumab in clinical samples may be useful for optimizing extended interval dosing and reducing the risk of PML. METHODS: In vitro natalizumab arm exchange was conducted, along with peptide mimotope and anti-idiotype surface capture chemistry, to enable the development of enzyme-linked immunosorbent assays. RESULTS: An assay using a unique peptide Veritope TM was developed, which can exclusively bind to bivalent natalizumab. In combination with enzyme-linked immunosorbent assays that quantifies total natalizumab, the assay system allows quantification of both natalizumab forms. CONCLUSIONS: In this article, a novel assay for the quantification of unexchanged and exchanged natalizumab variants in clinical samples was developed. This assay will enable investigations into the clinical significance of the relationship of PK/PD with the monovalent-to-bivalent ratio, as it relates to the efficacy of the drug and risk of PML.

Techno-economic Analysis of Sustainable Biofuels for Marine Transportation.

Renewable, low-carbon biofuels offer the potential opportunity to decarbonize marine transportation. This paper presents a comparative techno-economic analysis and process sustainability assessment of four conversion pathways: (1) hydrothermal liquefaction (HTL) of wet wastes such as sewage sludge and manure; (2) fast pyrolysis of woody biomass; (3) landfill gas Fischer-Tropsch synthesis; and (4) lignin-ethanol oil from the lignocellulosic ethanol biorefinery utilizing reductive catalytic fractionation. These alternative marine biofuels have a modeled minimum fuel selling price between $1.68 and $3.98 per heavy fuel oil gallon equivalent in 2016 U.S. dollars based on a mature plant assessment. The selected pathways also exhibit good process sustainability performance in terms of water intensity compared to the petroleum refineries. Further, the O and S contents of the biofuels vary widely. While the non-HTL biofuels exhibit negligible S content, the raw biocrudes via HTL pathways from sludge and manure show relatively high S contents (>0.5 wt %). Partial or full hydrotreatment can effectively lower the biocrude S content. Additionally, co-feeding with other low-sulfur wet wastes such as food waste can provide another option to produce raw biocrude with lower S content to meet the target with further hydrotreatment. This study indicates that biofuels could be a cost-effective fuel option for the marine sector. Marine biofuels derived from various feedstocks and conversion technologies could mitigate marine biofuel adoption risk in terms of feedstock availability and biorefinery economics.