Implementation of a High-Level Isolation Unit Readiness Checklist in the Irish Setting.

A high-level isolation unit (HLIU) is a specially designed biocontainment unit for suspected or confirmed high-consequence infectious diseases. For most HLIUs, maintaining readiness during times of inactivity is a challenge. In this case study, we describe a checklist approach to assess HLIU readiness to rapidly operate upon activation.

Mechanistic modeling of empty-full separation in recombinant adeno-associated virus production using anion-exchange membrane chromatography.

Recombinant adeno-associated viral vectors (rAAVs) have become an industry-standard technology in the field of gene therapy, but there are still challenges to be addressed in their biomanufacturing. One of the biggest challenges is the removal of capsid species other than that which contains the gene of interest. In this work, we develop a mechanistic model for the removal of empty capsids-those that contain no genetic material-and enrichment of full rAAV using anion-exchange membrane chromatography.

Tumor-wide RNA splicing aberrations generate immunogenic public neoantigens.

T-cell-mediated immunotherapies are limited by the extent to which cancer-specific antigens are homogenously expressed throughout a tumor. We reasoned that recurrent splicing aberrations in cancer represent a potential source of tumor-wide and public neoantigens, and to test this possibility, we developed a novel pipeline for identifying neojunctions expressed uniformly within a tumor across diverse cancer types. Our analyses revealed multiple neojunctions that recur across patients and either exhibited intratumor heterogeneity or, in some cases, were tumor-wide.

HepCare Plus: Enhancing Primary Care Identification and Treatment of Hepatitis C Virus in High-Risk Individuals.

Hepatitis C Virus (HCV) disproportionately affects people who inject drugs, migrants, prisoners and the homeless. An integrated, peer-led model of care involving primary and secondary care is required to enhance the identification and treatment of HCV in these marginalised groups. HepCare Plus builds on the network and achievements of HepCare Europe (a co-funded Third Health Programme of the European Union/Health Service Executive project).

Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.

Background: Up to 37.7% of patients experience symptoms beyond 12 weeks after infection with SARS-CoV-2. To date care for people with long covid has centred around multidisciplinary rehabilitation, self care and self pacing.

Assessing the impact of COVID-19 at 1-year using the SF-12 questionnaire: Data from the Anticipate longitudinal cohort study.

Background: Few studies to date have explored the health-related quality of life (HRQoL) in patients with long COVID.

Methods: The Anticipate Study is a prospective single-centre observational cohort study. Hospitalised and nonhospitalised patients were seen at a dedicated post-COVID clinic at a 2-4 month (Timepoint 1) and 7-14 month follow-up (Timepoint 2).

Taking the Hinge off: An Approach to Effector-Less Monoclonal Antibodies.

A variety of Fc domain engineering approaches for abrogating the effector functions of mAbs exists. To address some of the limitations of the current Fc domain silencing approaches, we are exploring a less commonly considered option which relies on the deletion of the hinge. Removal of the hinge domain in humanized IgG1 and IgG4 mAbs obliterates their ability to bind to activating human Fc gamma receptors I and IIIA, while leaving their ability to engage their target antigen intact.

Rational design of peptide affinity ligands for the purification of therapeutic enzymes.

Non-mAb biologics represent a growing class of therapeutics under clinical development. Although affinity chromatography is a potentially attractive approach for purification, the development of platform technologies, such as Protein A for mAbs, has been challenging due to the inherent chemical and structural diversity of these molecules. Here, we present our studies on the rapid development of peptide affinity ligands for the purification of biologics using a prototypical enzyme therapeutic in clinical use.

QSAR models for prediction of chromatographic behavior of homologous Fab variants.

While quantitative structure activity relationship (QSAR) models have been employed successfully for the prediction of small model protein chromatographic behavior, there have been few reports to date on the use of this methodology for larger, more complex proteins. Recently our group generated focused libraries of antibody Fab fragment variants with different combinations of surface hydrophobicities and electrostatic potentials, and demonstrated that the unique selectivities of multimodal resins can be exploited to separate these Fab variants. In this work, results from linear salt gradient experiments with these Fabs were employed to develop QSAR models for six chromatographic systems, including multimodal (Capto MMC, Nuvia cPrime, and two novel ligand prototypes), hydrophobic interaction chromatography (HIC; Capto Phenyl), and cation exchange (CEX; CM Sepharose FF) resins.

Evaluation of selectivity in homologous multimodal chromatographic systems using in silico designed antibody fragment libraries.

This study describes the in silico design, surface property analyses, production and chromatographic evaluations of a diverse set of antibody Fab fragment variants. Based on previous findings, we hypothesized that the complementarity-determining regions (CDRs) constitute important binding sites for multimodal chromatographic ligands. Given that antibodies are highly diversified molecules and in particular the CDRs, we set out to examine the generality of this result.

The effect of geometrical presentation of multimodal cation-exchange ligands on selective recognition of hydrophobic regions on protein surfaces.

The effects of spatial organization of hydrophobic and charged moieties on multimodal (MM) cation-exchange ligands were examined by studying protein retention behavior on two commercial chromatographic media, Capto™ MMC and Nuvia™ cPrime™. Proteins with extended regions of surface-exposed aliphatic residues were found to have enhanced retention on the Capto MMC system as compared to the Nuvia cPrime resin. The results further indicated that while the Nuvia cPrime ligand had a strong preference for interactions with aromatic groups, the Capto MMC ligand appeared to interact with both aliphatic and aromatic clusters on the protein surfaces.

Defining the property space for chromatographic ligands from a homologous series of mixed-mode ligands.

A homologous ligand library based on the commercially-available Nuvia cPrime ligand was generated to systematically explore various features of a multimodal cation-exchange ligand and to identify structural variants that had significantly altered chromatographic selectivity. Substitution of the polar amide bond with more hydrophobic chemistries was found to enhance retention while remaining hydrophobically-selective for aromatic residues. In contrast, increasing the solvent exposure of the aromatic ring was observed to strengthen the ligand affinity for both types of hydrophobic residues.

Candida albicans stimulates IL-23 release by human dendritic cells and downstream IL-17 secretion by Vδ1 T cells.

γδ T cells expressing the Vδ1 TCR are expanded in patients with HIV infection. We show in this article that circulating Vδ1 T cell numbers are particularly high in patients with HIV and candidiasis, and that these cells expand and produce IL-17 in response to Candida albicans in vitro. Although C.

Investigation of protein selectivity in multimodal chromatography using in silico designed Fab fragment variants.

In this study, a unique set of antibody Fab fragments was designed in silico and produced to examine the relationship between protein surface properties and selectivity in multimodal chromatographic systems. We hypothesized that multimodal ligands containing both hydrophobic and charged moieties would interact strongly with protein surface regions where charged groups and hydrophobic patches were in close spatial proximity. Protein surface property characterization tools were employed to identify the potential multimodal ligand binding regions on the Fab fragment of a humanized antibody and to evaluate the impact of mutations on surface charge and hydrophobicity.

Phenylboronate chromatography selectively separates glycoproteins through the manipulation of electrostatic, charge transfer, and cis-diol interactions.

Phenylboronate chromatography (PBC) has been applied for several years, however details regarding the mechanisms of interactions between the ligand and biomolecules are still scarce. The goal of this work is to investigate the various chemical interactions between proteins and their ligands, using a protein library containing both glycosylated and nonglycosylated proteins. Differences in the adsorption of these proteins over a pH range from 4 to 9 were related to two main properties: charge and presence of glycans.

Design of peptide affinity ligands for S-protein: a comparison of combinatorial and de novo design strategies.

Design of peptide affinity ligands against biological targets is important for a broad range of applications. Here, we report on de novo and combinatorial strategies for the design of high-affinity and high-specificity peptides against S-protein as a target. The peptide libraries employed in this study contain (1) consensus motif (CM) sequences identified from high-throughput phage combinatorial screening, (2) point mutations of CM sequences, and (3) de novo sequences rationally designed based on stereo-chemical information of the complex between S-protein and its natural ligand, S-peptide.

Contribution of genetic background, traditional risk factors, and HIV-related factors to coronary artery disease events in HIV-positive persons.

Background: Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection.

Methods: In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis.

Risk-benefit analysis of pulmonary CT angiography in patients with suspected pulmonary embolus.

Objective: The objective of our study was to estimate the mortality benefit-to-risk ratio of pulmonary CT angiography (CTA) by setting (ambulatory [emergency department or outpatient] or inpatient), age, and sex.

Materials And Methods: A retrospective evaluation of 1424 consecutive pulmonary CTA examinations was performed and the following information was recorded: examination setting, patient age, patient sex, pulmonary CTA interpretation for pulmonary embolus (PE), and CT radiation exposure (dose-length product). We estimated mortality benefit of pulmonary CTA by multiplying the rate of positive pulmonary CTA examinations by published estimates of mortality of untreated PE in ambulatory and inpatient settings.

The missing left atrial appendage.

A 34 year old man underwent a transesophageal echocardiogram (TEE) prior to implantation of a biventricular ICD and DC cardioversion, to exclude left atrium and left atrial appendage thrombus. He had a history of repaired tetralogy of Fallot as a child, Stickler syndrome, atrial flutter and was status post recent mitral valve replacement, pulmonary valve replacement and tricuspid valve repair. The left atrial appendage was not visualized on TEE.

Effect of patient socioeconomic status on perceptions of first- and second-year medical students.

Background: Physician decision-making and perceptions of patients are affected by a patient's socioeconomic status (SES). We sought to determine if the perceptions of first- and second-year medical students are similarly affected. We also wanted to determine whether a student's own SES affects his or her perceptions of patients from a low or high SES background.

Hypertonic resuscitation of hemorrhagic shock upregulates the anti-inflammatory response by alveolar macrophages.

Background: Resuscitated hemorrhagic shock predisposes patients to the development of acute respiratory distress syndrome (ARDS). Hypertonic saline (HTS) has been shown to inhibit immune cell activation in response to lipopolysaccharide (LPS) in vitro and to reduce lung damage when used for resuscitation of hemorrhagic shock in vivo. We hypothesize that HTS resuscitation of hemorrhagic shock may exert this anti-inflammatory effect by modulating alveolar macrophage function leading to an altered balance between the proinflammatory and the counter-inflammatory response.