The LDL receptor binding domain of apolipoprotein E directs the relative orientation of its C-terminal segment in reconstituted nascent HDL.

Apolipoprotein E (apoE) (299 residues) is a highly helical protein that plays a critical role in cholesterol homeostasis. It comprises a four-helix bundle N-terminal (NT) and a C-terminal (CT) domain that can exist in lipid-free and lipid-associated states. In humans, there are two major apoE isoforms, apoE3 and apoE4, which differ in a single residue in the NT domain, with apoE4 strongly increasing risk of Alzheimer's disease (AD) and cardiovascular diseases (CVD). It has been proposed that the CT domain initiates rapid lipid binding, followed by a slower NT domain helix bundle opening and lipid binding to yield discoidal reconstituted high density lipoprotein (rHDL). However, the contribution of the NT domain on the CT domain organization in HDL remains poorly understood. To understand this, we employed Cys-specific cross-linking and spatially-sensitive fluorophores in the NT and CT domains of apoE3 and apoE4, and in isolated CT domain. We noted that the helices in isolated CT domain are oriented parallel to those in the neighboring molecule in rHDL, whereas full length apoE3 and apoE4 adopt either an anti-parallel or hairpin-like organization. It appears that the bulky NT domain determines the spatial organization of its CT domain in rHDL, a finding that has significance for apoE4, which is more susceptible to proteolytic cleavage in AD brains, showing increased accumulation of neurotoxic NT and CT fragments. We envisage that the structural organization of HDL apoE would have profound functional consequences in its ability to regulate cholesterol homeostasis in AD and CVD.

Review of pharmacologic and immunologic agents in the management of COVID-19.

The novel coronavirus disease 2019 (COVID-19) is the third coronavirus outbreak in the last two decades. Emerging and re-emerging infections like COVID-19 pose serious challenges of the paucity of information and lack of specific cure or vaccines. This leaves utilisation of existing scientific data on related viral infections and repurposing relevant aetiologic and supportive therapies as the best control approach while novel strategies are developed and trialled. Many promising antiviral agents including lopinavir, ritonavir, remdesivir, umifenovir, darunavir, and oseltamivir have been repurposed and are currently trialled for the care for COVID-19 patients. Adjunct therapies for the management of symptoms and to provide support especially in severe and critically ill patients have also been identified. This review provides an appraisal of the current evidence for the rational use of frontline therapeutics in the management of COVID-19. It also includes updates regarding COVID-19 immunotherapy and vaccine development.

Supramolecular Double Helices from Small C3-Symmetrical Molecules Aggregated in Water.

Supramolecular fibers in water, micrometers long and several nanometers in width, are among the most studied nanostructures for biomedical applications. These supramolecular polymers are formed through a spontaneous self-assembly process of small amphiphilic molecules by specific secondary interactions. Although many compounds do not possess a stereocenter, recent studies suggest the (co)existence of helical structures, albeit in racemic form. Here, we disclose a series of supramolecular (co)polymers based on water-soluble benzene-1,3,5-tricarboxamides (BTAs) that form double helices, fibers that were long thought to be chains of single molecules stacked in one dimension (1D). Detailed cryogenic transmission electron microscopy (cryo-TEM) studies and subsequent three-dimensional-volume reconstructions unveiled helical repeats, ranging from 15 to 30 nm. Most remarkable, the pitch can be tuned through the composition of the copolymers, where two different monomers with the same core but different peripheries are mixed in various ratios. Like in lipid bilayers, the hydrophobic shielding in the aggregates of these disc-shaped molecules is proposed to be best obtained by dimer formation, promoting supramolecular double helices. It is anticipated that many of the supramolecular polymers in water will have a thermodynamic stable structure, such as a double helix, although small structural changes can yield single stacks as well. Hence, it is essential to perform detailed analyses prior to sketching a molecular picture of these 1D fibers.

The Postencounter Form System: Viewpoint on Efficient Data Collection Within Electronic Health Records.

Electronic health records (EHRs) offer opportunities for research and improvements in patient care. However, challenges exist in using data from EHRs due to the volume of information existing within clinical notes, which can be labor intensive and costly to transform into usable data with existing strategies. This case report details the collaborative development and implementation of the postencounter form (PEF) system into the EHR at the Road Home Program at Rush University Medical Center in Chicago, IL to address these concerns with limited burden to clinical workflows. The PEF system proved to be an effective tool with over 98% of all clinical encounters including a completed PEF within 5 months of implementation. In addition, the system has generated over 325,188 unique, readily-accessible data points in under 4 years of use. The PEF system has since been deployed to other settings demonstrating that the system may have broader clinical utility.

Prognostic significance of ischemic electrocardiographic changes with regadenoson stress myocardial perfusion imaging.

BACKGROUND: In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), the prognostic value of ischemic ST-segment depression (ST↓) and the optimal ST↓ threshold have not been studied. METHODS: A retrospective cohort study of consecutive patients referred for regadenoson stress MPI was conducted. Patients with uninterpretable ECG were excluded. Two diagnostic thresholds of horizontal or downsloping ST↓ were studied, ≥ 0.5 mm and ≥ 1.0 mm. The primary endpoint was the composite major adverse cardiac events (MACE) of cardiac death, myocardial infarction, or coronary revascularization. RESULTS: Among 8615 subjects (mean age 62 ± 13 years; 55% women), 89 (1.0%) had ST↓ ≥ 1.0 mm and 133 (1.5%) had ST↓ ≥ 0.5 mm. Regadenoson-induced ST↓ was more common in women (P < .001). Mean follow-up was 2.5 ± 2.2 years. After multivariate adjustment, ST↓ ≥ 1.0 mm was associated with a non-significant increase in MACE risk (P = .069), irrespective to whether MPI was abnormal (P = .162) or normal (P = .214). Ischemic ST↓ ≥ 0.5 mm was independently associated with MACE in the entire cohort (HR 2.14; CI 1.38-3.32; P = .001), whether MPI is normal (HR 2.07; CI 1.07-4.04; P = .032) or abnormal (HR 2.24; CI 1.23-4.00; P = .007), after adjusting for clinical and imaging covariates. An ST↓ threshold of ≥ 0.5 mm provided greater incremental prognostic value beyond clinical and imaging parameters (Δχ2 = 12.78; P < .001) than ≥ 1.0 mm threshold (Δχ2 = 3.72; P = .093). CONCLUSION: Regadenoson-induced ischemic ST↓ is more common in women and it provides a modest independent prognostic value beyond MPI and clinical parameters. ST↓ ≥ 0.5 mm is a better threshold than ≥ 1.0 mm to define ECG evidence for regadenoson-induced myocardial ischemia.

Supramolecular Copolymerization as a Strategy to Control the Stability of Self-Assembled Nanofibers.

A major challenge in supramolecular polymerization is controlling the stability of the polymers formed, that is, controlling the rate of monomer exchange in the equilibrium between monomer and polymer. The exchange dynamics of supramolecular polymers based on benzene-1,3,5-tricarboxamide (BTA) can be regulated by copolymerizing molecules with dendronized (dBTA) and linear (nBTA) ethylene glycol-based water-soluble side chains. Whereas nBTAs form long nanofibers in water, dBTAs do not polymerize, forming instead small spherical aggregates. The copolymerization of the two BTAs results in long nanofibers. The exchange dynamics of both the BTA monomers in the copolymer are significantly slowed down in the mixed systems, leading to a more stable copolymer, while the morphology and spectroscopic signature of the copolymers are identical to that of nBTA homopolymer. This copolymerization is the supramolecular counterpart of styrene/ maleic anhydride copolymerization.

Anxiety symptoms in regular school students in Mumbai City, India.

Aim: Anxiety disorders usually remain undiagnosed in school students owing to the internalized nature of their symptoms. The present study was conducted with the primary objective of evaluating the prevalence of anxiety symptoms in school students in Mumbai. A secondary objective was to assess the impact of variables (age, gender, presence of sibling, and type of school curriculum or school) on anxiety symptoms. Materials and Methods: Study cases (8-15 year olds) were recruited by nonprobability sampling from four English-medium schools. Anxiety was measured using Spence Children's Anxiety Scale (SCAS)-child self-report questionnaire. T-scores (total and subscales) were calculated and cut-off scores of> 60 were considered as significant. Results: Symptoms of overall anxiety were present in 10.8% (53/493) of the students. Older students (12-15 year olds) had greater odds of having overall anxiety symptoms (crude OR = 4.36, 95% CI 2.27 to 8.39, P < 0.0001). Symptoms of all anxiety disorders were present in the 493 participants, with obsessions/compulsions and fears of physical injury being the most common (in 29.6% and 27.2%, respectively). Older students and boys had greater odds of having obsessions/compulsions (crude OR = 2.32, 95% CI 1.56 to 3.44, P < 0.0001; and crude OR = 1.54, 95% CI 1.04 to 2.27, P= 0.035, respectively]. Students with sibling (s) had greater odds of having fears of physical injury (crude OR = 0.48, 95% CI 0.30 to 0.78, P= 0.003). Conclusions: There is an urgent need to screen school students in our city for anxiety disorders.

Aggregation Behavior of Non-ionic Twinned Amphiphiles and Their Application as Biomedical Nanocarriers.

A new class of twinned amphiphiles was developed by conjugating a pair of hydrophilic head groups from mPEG chains (Mn : 350 or 1000) and a pair of hydrophobic segments from linear alkyl chains (C11 or C18 ) through a novel spacer synthesized from glycerol and p-hydroxybenzoic acid. The aggregation phenomena of the amphiphiles were proven by DLS and fluorescence experiments, whereas size and morphology of the aggregates were evaluated by cryo-TEM. The measurements proved the formation of globular, thread-like or rod-like micelles as well as planar double-layer assemblies, depending on the amphiphile's molecular structure. The applicability of these non-ionic amphiphilic systems as nanocarriers for hydrophobic guest molecules was demonstrated by encapsulating a hydrophobic dye, Nile Red, and a hydrophobic drug, Nimodipine. The transport capacity results for both Nimodipine and Nile Red prove them as a promising candidate for drug delivery.

Perioperative death: Its implications and management.

Death to most people is a major life event. Nothing in this world prepares us to face and manage the perioperative death although the majority of anesthesiologists will be involved in an intraoperative death during the course of their careers. Whether death on the table was expected or occurred when least expected or may be even later, the anesthesiologist is most likely to be affected emotionally, physically in his personal life, and as well as will have an influence on his professional career. Anesthesiologists as perioperative physicians are likely to experience death on the operating table at some time in their careers. In case of perioperative death, meticulous record keeping including time of occurrence of event and methods and medications used during resuscitation, nature of the problem, and all sequence of events should be adopted to breaking bad news with relatives and blame game should be avoided. The anesthesiologist and the relatives of the patient should also be given emotional support to come out of this untoward event. In this article, we have highlighted the various factors and causes leading on to perioperative death and if in case such an event occurs, what are the protocols to be followed, including medicolegal aspects, giving emotional support to the concerned anesthesiologist, dealing with the relatives of the patient sympathetically, etc. We have also enumerated the various precautions to be taken to prevent perioperative mortality in this article.

Crosslinked Redox-Responsive Micelles Based on Lipoic Acid-Derived Amphiphiles for Enhanced siRNA Delivery.

Successful application of gene silencing approaches critically depends on systems that are able to safely and efficiently deliver genetic material such as small interfering RNA (siRNA). Due to their beneficial well-defined dendritic nanostructure, self-assembling dendrimers are emerging as promising nanovectors for siRNA delivery. However, these kinds of vectors are plagued with stability issues, especially when considered for in vivo applications. Therefore, in the present study, disulfide-based temporarily fixed micelles are developed that can degrade upon reductive conditions, and thus lead to efficient cargo release. In detail, lipoic acid-derived crosslinked micelles are synthesized based on small polymerizable dendritic amphiphiles. Particularly, one candidate out of this series is able to efficiently release siRNA due to its redox-responsive biodegradable profile when exposed to simulated intracellular environments. As a result, the reduction-triggered disassembly leads to potent gene silencing. In contrast, noncrosslinkable, structurally related constructs fails under the tested assay conditions, thereby confirming the applied rational design approach and demonstrating its large potential for future in vivo applications.

Is anxiety more common in school students with newly diagnosed specific learning disabilities? A cross-sectional questionnaire-based study in Mumbai, Maharashtra, India.

BACKGROUND AND OBJECTIVES: School students with specific learning disabilities (SpLDs) experience chronic academic underachievement and resultant stress. The present study aimed to determine if school students with newly diagnosed SpLD were more likely to have anxiety than their regular peers. MATERIALS AND METHODS: The study cases (aged 8-15 years) were recruited from our institute's learning disability clinic. The matched controls were recruited from four schools in Mumbai, Maharashtra, India. Anxiety was measured using the Spence Children's Anxiety Scale (SCAS)-child self-report version questionnaire. Median SCAS scores and the proportion of students with an SCAS score in the "clinical anxiety" range were compared between the groups. RESULTS: SCAS scores were significantly higher in 8-11-year-old learning-disabled male and female students (P < 0.0001 for both groups) and 12-15-year-old female students (P = 0.004), as compared with matched controls. A significantly higher number of learning-disabled students were found to have "clinical anxiety" [24.64% vs. 4.35%, crude odds ratio (OR) = 7.19, 95% confidence interval (CI) 2.91-17.78, P = 0.0001], as compared with the controls regardless of gender, age group, presence of comorbid attention-deficit/hyperactivity disorder (ADHD), or associated medical conditions. A significantly higher proportion of 8-11-year-old learning-disabled students, especially males, were found to have "clinical anxiety" as compared with 12-15-year-old learning-disabled students (crude OR = 4.38, 95% CI 1.94-9.92, P = 0.0004). Gender, presence of comorbid ADHD or associated medical conditions, and type of school attended or curriculum did not impact the prevalence of "clinical anxiety" in learning-disabled students. INTERPRETATION AND CONCLUSIONS: Students with newly diagnosed SpLD have greater odds of being "clinically anxious" relative to their regular peers. We recommend screening for anxiety in children with SpLD immediately after diagnosis so that their optimum rehabilitation can be facilitated.

Supramolecular Architectures of Dendritic Amphiphiles in Water.

Dendritic molecules are an exciting research topic because of their highly branched architecture, multiple functional groups on the periphery, and very pertinent features for various applications. Self-assembling dendritic amphiphiles have produced different nanostructures with unique morphologies and properties. Since their self-assembly in water is greatly relevant for biomedical applications, researchers have been looking for a way to rationally design dendritic amphiphiles for the last few decades. We review here some recent developments from investigations on the self-assembly of dendritic amphiphiles into various nanostructures in water on the molecular level. The main content of the review is divided into sections according to the different nanostructure morphologies resulting from the dendritic amphiphiles' self-assembly. Finally, we conclude with some remarks that highlight the self-assembling features of these dendritic amphiphiles.

Dendronylation: Residue-specific chemoselective attachment of oligoglycerol dendrimers on proteins with noncanonical amino acids.

Polyglycerol dendrimers as an important class of polymeric materials especially attractive for covalent attachment to therapeutic proteins as a useful alternative to traditional PEGylation procedures. Herein, we combine in vivo noncanonical amino acid (ncAA) incorporation and chemoselective conjugation in vitro to produce novel hybrid protein-dendrimer conjugates with the defined architectures. We incorporated Azidohomoalanine (Aha) as methionine substitute in vivo into various protein scaffolds to allow non-invasive dendrimer conjugations (dendronylation). Our approach makes recombinant proteins accessible for the design of multivalent dendrimer conjugates since it enables the preparation of many sequences with various positions for regioselective dendronylation.

Systematic adjustment of charge densities and size of polyglycerol amines reduces cytotoxic effects and enhances cellular uptake.

Excessive cationic charge density of polyplexes during cellular uptake is still a major hurdle in the field of non-viral gene delivery. The most efficient cationic vectors such as polyethylene imine (PEI) or polyamidoamine (PAMAM) can be highly toxic and may induce strong side effects due to their high cationic charge densities. Alternatives like polyethylene glycol (PEG) are used to 'shield' these charges and thus to reduce the cytotoxic effects known for PEI/PEG-core-shell architectures. In this study, we compared the ability of hyperbranched polyglycerol amines (hPG amines) with different amine densities and molecular weights as non-viral cationic vectors for DNA delivery. By adjusting the hydroxyl to amine group ratio on varying molecular weights, we were able to perform a systematic study on the cytotoxic effects caused by the effective charge density in correlation to size. We could demonstrate that carriers with moderate charge density have a higher potential for effective DNA delivery as compared to high/low charged ones independent of their size, but the final efficiency can be optimized by the molecular weight. We analyzed the physicochemical properties and cellular uptake capacity as well as the cytotoxicity and transfection efficiency of these new vector systems.

Design and implementation of a privacy preserving electronic health record linkage tool in Chicago.

OBJECTIVE: To design and implement a tool that creates a secure, privacy preserving linkage of electronic health record (EHR) data across multiple sites in a large metropolitan area in the United States (Chicago, IL), for use in clinical research. METHODS: The authors developed and distributed a software application that performs standardized data cleaning, preprocessing, and hashing of patient identifiers to remove all protected health information. The application creates seeded hash code combinations of patient identifiers using a Health Insurance Portability and Accountability Act compliant SHA-512 algorithm that minimizes re-identification risk. The authors subsequently linked individual records using a central honest broker with an algorithm that assigns weights to hash combinations in order to generate high specificity matches. RESULTS: The software application successfully linked and de-duplicated 7 million records across 6 institutions, resulting in a cohort of 5 million unique records. Using a manually reconciled set of 11 292 patients as a gold standard, the software achieved a sensitivity of 96% and a specificity of 100%, with a majority of the missed matches accounted for by patients with both a missing social security number and last name change. Using 3 disease examples, it is demonstrated that the software can reduce duplication of patient records across sites by as much as 28%. CONCLUSIONS: Software that standardizes the assignment of a unique seeded hash identifier merged through an agreed upon third-party honest broker can enable large-scale secure linkage of EHR data for epidemiologic and public health research. The software algorithm can improve future epidemiologic research by providing more comprehensive data given that patients may make use of multiple healthcare systems.

Towards engineering of self-assembled nanostructures using non-ionic dendritic amphiphiles.

Engineering nanostructures of defined size and morphology is a great challenge in the field of self-assembly. Herein we report on the formation of supramolecular nanostructures of defined morphologies with subtle structural changes for a new series of dendritic amphiphiles. Subsequently, we studied their application as nanocarriers for guest molecules.

Online monitoring the isomerization of an azobenzene-based dendritic bolaamphiphile using ion mobility-mass spectrometry.

Ion mobility-mass spectrometry was used to obtain detailed information about the kinetics of the light-induced cis/trans isomerization process of a new supramolecular azobenzene-based bolaamphiphile. Further experiments revealed that the investigated light-induced structural transition dramatically influences the aggregation behaviour of the molecule.

Dendritic core-shell systems as soft drug delivery nanocarriers.

Unimolecular micelles are covalently bound molecular architectures and therefore highly stable which makes them particularly attractive for drug delivery. Accordingly, many reports in the literature emphasize the importance of these molecular architectures for nanomedicine. This conceptual review will present some of the recent advances in the application of these dendritic core-shell systems for drug delivery. Unimolecular micelles based on hyperbranched and dendritic cores will be discussed and sorted by the nature of their core and structure.

Carbon-based cores with polyglycerol shells - the importance of core flexibility for encapsulation of hydrophobic guests.

Two core-shell nanoparticles with polyglycerol shells and sp3 carbon cores with different flexibilities (soft dendritic polyethylene and hard nanodiamond) were synthesized, their encapsulation capacities were compared, and their ability to transport into tumor cells was investigated. The nanocarrier with a soft core was superior to the hard one.