Numerical modeling and in situ small angle X-ray scattering characterization of ultra-small SPION magnetophoresis in a high field and gradient separator

Magnetic nanoparticles (MNPs) have recently gained significant attention in various fields, including chemical and biomedical applications, due to their exceptional properties. However, separating MNPs from solution via magnetophoresis is challenging when MNPs are smaller than 50 nm as Brownian forces become on the order of the magnetic forces. In this study, we successfully separated small MNPs (5-30 nm) by utilizing high magnetic fields and gradients generated by economical permanent magnets. In situ small angle X-ray scattering (SAXS) was used to investigate the time-dependent concentration changes in the ferrofluid, and the results validated that only the 30 nm particles experienced particle aggregation or agglomeration, indicating that dipole-dipole interactions did not play a discernable role in the separation process for particles smaller than ∼15 nm. However, numerical simulations have provided further validation that in the absence of particle-particle interactions, even MNPs with diameters less than 15 nm exhibited magnetophoresis that effectively counteracted the effects of Brownian motion.

The Effects of a Perindopril-Based Regimen in Relation to Statin Use on the Outcomes of Patients with Vascular Disease: a Combined Analysis of the ADVANCE, EUROPA, and PROGRESS Trials

PURPOSE

To study the effects of a perindopril-based regimen on cardiovascular (CV) outcomes in patients with vascular disease in relation to background statin therapy.

METHODS

A pooled analysis of the randomized ADVANCE, EUROPA, and PROGRESS trials was performed to evaluate CV outcomes in 29,463 patients with vascular disease treated with perindopril-based regimens versus placebo. The primary endpoint was a composite of CV mortality, nonfatal myocardial infarction, and stroke. Multivariable Cox regression analyses were performed to assess the effects of a perindopril-based regimen versus placebo in relation to statin use.

RESULTS

At randomization, 39.5% of the overall combined study population used statins. After a mean follow-up of 4.0 years (SD 1.0), the cumulative event-free survival was highest in the statin/perindopril group and lowest in the no statin/placebo group (91.2% vs. 85.6%, respectively, log-rank p < 0.001). In statin users (adjusted hazard ratio [aHR] 0.87, 95% confidence interval [CI] 0.77-0.98) and non-statin users (aHR 0.80, 95% CI 0.74-0.87), a perindopril-based regimen was associated with a significantly lower risk of the primary endpoint when compared to placebo. The additional treatment effect appeared numerically greater in non-statin users, but the observed difference was statistically nonsignificant.

CONCLUSION

Our data suggest that the treatment benefits of a perindopril-based regimen in patients with vascular disease are independent of statin use.

Kinetic and Parametric Analysis of the Separation of Ultra-Small, Aqueous Superparamagnetic Iron Oxide Nanoparticle Suspensions under Quadrupole Magnetic Fields

Superparamagnetic iron oxide nanoparticles (SPIONs) have gathered tremendous scientific interest, especially in the biomedical field, for multiple applications, including bioseparation, drug delivery, etc. Nevertheless, their manipulation and separation with magnetic fields are challenging due to their small size. We recently reported the coupling of cooperative magnetophoresis and sedimentation using quadrupole magnets as a promising strategy to successfully promote SPION recovery from media. However, previous studies involved SPIONs dispersed in organic solvents (non-biocompatible) at high concentrations, which is detrimental to the process economy. In this work, we investigate, for the first time, the magnetic separation of 20 nm and 30 nm SPIONs dispersed in an aqueous medium at relatively low concentrations (as low as 0.5 g·L-1) using our custom, permanent magnet-based quadrupole magnetic sorter (QMS). By monitoring the SPION concentrations along the vessel within the QMS, we estimated the influence of several variables in the separation and analyzed the kinetics of the process. The results obtained can be used to shed light on the dynamics and interplay of variables that govern the fast separation of SPIONs using inexpensive permanent magnets.

Single cell transcriptomic analysis of HPV16-infected epithelium identifies a keratinocyte subpopulation implicated in cancer

Persistent HPV16 infection is a major cause of the global cancer burden. The viral life cycle is dependent on the differentiation program of stratified squamous epithelium, but the landscape of keratinocyte subpopulations which support distinct phases of the viral life cycle has yet to be elucidated. Here, single cell RNA sequencing of HPV16 infected compared to uninfected organoids identifies twelve distinct keratinocyte populations, with a subset mapped to reconstruct their respective 3D geography in stratified squamous epithelium. Instead of conventional terminally differentiated cells, an HPV-reprogrammed keratinocyte subpopulation (HIDDEN cells) forms the surface compartment and requires overexpression of the ELF3/ESE-1 transcription factor. HIDDEN cells are detected throughout stages of human carcinogenesis including primary human cervical intraepithelial neoplasias and HPV positive head and neck cancers, and a possible role in promoting viral carcinogenesis is supported by TCGA analyses. Single cell transcriptome information on HPV-infected versus uninfected epithelium will enable broader studies of the role of individual keratinocyte subpopulations in tumor virus infection and cancer evolution.

The Unique Magnetic Signature of Sickle Red Blood Cells: A Comparison Between the Red Blood Cells of Transfused and Non-Transfused Sickle Cell Disease Patients and Healthy Donors

Sickle cell disease (SCD) is an inherited blood disorder that affects millions of people worldwide, especially in low-resource regions of the world, where a rapid and affordable test to properly diagnose the disease would be highly valued. Magnetophoresis is a technique that could simultaneously analyze, quantify, and potentially separate the patient's sickle red blood cells (RBCs) from healthy RBCs, but the magnetic characteristics of sickle RBCs have yet to be reported. In this work, we present the single cell magnetic characterization of RBCs obtained from SCD patients. Sufficient single cells are analyzed from patient samples undergoing transfusion therapy and not yet having transfusion therapy (TP and NTP, respectively), such that means and distributions of these single RBC mobilities are created in the form of histograms which facilitated comparison to RBCs from healthy donors (HD). The magnetic characterization is obtained using a technique known as Cell Tracking Velocimetry (CTV) that quantitatively characterizes the RBC response to magnetic and gravitational fields. The magnetic properties of RBCs containing oxygenated, deoxygenated hemoglobin (Hb) and methemoglobin (oxyHb-RBCs, deoxyHb-RBCs, and metHb-RBCs) are further determined. The NTP samples reported the highest magnetic character, especially when compared to oxyHb-RBCs from HD, which implies impaired oxygen binding capabilities. Also, the oxygen-Hb equilibrium curves are obtained to estimate the magnetic character of the cells under intermediate oxygen levels. Our results confirm higher magnetic moment of SCD blood (NTP) under intermediate oxygen levels. These data demonstrate the potential feasibility of magnetophoresis to identify, quantify and separate sickle RBCs from healthy RBCs.

SPIONs self-assembly and magnetic sedimentation in quadrupole magnets: Gaining insight into the separation mechanisms

Superparamagnetic iron oxide nanoparticles (SPIONs) are currently popular materials experiencing rapid development with potential application value, especially in biomedical and chemical engineering fields. Examples include wastewater management, bio-detection, biological imaging, targeted drug delivery and biosensing. While not exclusive, magnetically driven isolation methods are typically required to separate the desired entity from the media in specific applications and in their manufacture and/or quality control. However, due to the nano-size of SPIONs, their magnetic manipulation is affected by Brownian motion, adding considerable complexities. The two most common methods for SPION magnetic separation are high and low gradient magnetic separation (HGMS and LGMS, respectively). Nevertheless, the effect of specific magnetic energy fields on SPIONs, such as horizontal (perpendicular to gravity), high fields and gradients (higher than LGMS) on the horizontal magnetophoresis and vertical sedimentation of SPIONs has only recently been suggested as a way to separate very small particles (5 nm). In this work, we continue those studies on the magnetic separation of 5-30 nm SPIONs by applying fields and gradients perpendicular to gravity. The magnetic field was generated by permanent magnets arranged in quadrupolar configurations (QMS). Different conditions were studied, and multiple variables were evaluated, including the particle size, the initial SPIONs concentration, the temperature, the magnetic field gradient and the magnetic exposure time. Our experimental data show that particles are subjected to horizontal magnetic forces, to particle agglomeration due to dipole-dipole interactions, and to vertical sedimentation due to gravity. The particle size and the type of separator employed (i.e. different gradient and field distribution acting on the particle suspension) have significant effects on the phenomena involved in the separation, whereas the temperature and particle concentration affect the separation to a lesser extent. Finally, the separation process was observed to occur in less than 3 mins for our experimental conditions, which is encouraging considering the long operation time (up to days) necessary to separate particles of similar sizes in LGMS columns that also employ permanent magnets.

A comparison of structural features and vulnerability between government and nongovernment alcohol and other drug (AOD) treatment providers

OBJECTIVE

Both public (government-run), and not-for-profit (nongovernment) service providers provide alcohol and other drug (AOD) treatment services. Research has rarely studied the structural features of these providers, such as workforce characteristics, procurement arrangements, and funding security. The study reported here sought to document and analyze the differences between these two AOD treatment provider types in Australia.

METHODS

The study administered an online survey instrument targeted at managers of AOD treatment sites. The survey comprised three sections: (1) the service (e.g., treatment types); (2) workforce (e.g., total number of staff); and (3) funding and procurement arrangements (e.g., contract length). The study completed a total of 207 site surveys. The studied compared government and nongovernment services on structural features that may create a more or less sustainable or vulnerable service (funding arrangements, payment mechanisms, and contract length).

RESULTS

Government providers were more likely to provide medically oriented treatment types such as withdrawal management and pharmacotherapy, whereas nongovernment organization (NGO) providers were more likely to offer rehabilitation. Consistent with this, government services were more likely to employ medical professionals and nurses, indicative of a more medically oriented workforce, while NGO services were more likely to employ AOD workers, youth workers, peer workers, and counselors. Our data illustrate that NGO services were more likely to be subject to competitive tendering and to have shorter contract lengths, compared with government services, and overall to be more structurally vulnerable.

CONCLUSION

Despite the reliance on NGOs to provide the majority of specialist care (71% of all treatment episodes in Australia), these services are more vulnerable than their government counterparts. To ensure that a comprehensive suite of treatment services is available, procurement arrangements that support stability and security in nongovernment service providers and government service providers are essential.

A multicomponent screen for feeding behaviour and nutritional status in Drosophila to interrogate mammalian appetite-related genes

OBJECTIVE

More than 300 genetic variants have been robustly associated with measures of human adiposity. Highly penetrant mutations causing human obesity do so largely by disrupting satiety pathways in the brain and increasing food intake. Most of the common obesity-predisposing variants are in, or near, genes expressed highly in the brain, but little is known of their function. Exploring the biology of these genes at scale in mammalian systems is challenging. We sought to establish and validate the use of a multicomponent screen for feeding behaviour phenotypes, taking advantage of the tractable model organism Drosophila melanogaster.

METHODS

We validated a screen for feeding behaviour in Drosophila by comparing results after disrupting the expression of centrally expressed genes that influence energy balance in flies to those of 10 control genes. We then used this screen to explore the effects of disrupted expression of genes either a) implicated in energy homeostasis through human genome-wide association studies (GWAS) or b) expressed and nutritionally responsive in specific populations of hypothalamic neurons with a known role in feeding/fasting.

RESULTS

Using data from the validation study to classify responses, we studied 53 Drosophila orthologues of genes implicated by human GWAS in body mass index and found that 15 significantly influenced feeding behaviour or energy homeostasis in the Drosophila screen. We then studied 50 Drosophila homologues of 47 murine genes reciprocally nutritionally regulated in POMC and agouti-related peptide neurons. Seven of these 50 genes were found by our screen to influence feeding behaviour in flies.

CONCLUSION

We demonstrated the utility of Drosophila as a tractable model organism in a high-throughput genetic screen for food intake phenotypes. This simple, cost-efficient strategy is ideal for high-throughput interrogation of genes implicated in feeding behaviour and obesity in mammals and will facilitate the process of reaching a functional understanding of obesity pathogenesis.

Stratified effects of blood pressure-lowering treatment on long-term blood pressure: an individual patient-level meta-analysis involving 50 randomised trials and 334,219 participants

Background

Meta-analyses of randomised controlled trials (RCT) have shown the efficacy of pharmacologic lowering of blood pressure (BP) in reducing cardiovascular disease (CVD) risk. While efficacy has been shown across important patient characteristics, meta-analysis based on aggregate data could not fully account for potential sources of variation due to individual-level characteristics. Moreover, it is unclear if any variation in treatment effects due to patient characteristics are reflected in differential effects of BP-lowering treatment on long-term BP according to these characteristics.

Purpose

We determined the effects of BP-lowering treatment on repeated measures of blood pressure, identified trial- and participant-level sources of heterogeneity, and examined consistency of these BP-lowering effects across different patient characteristics.

Methods

We conducted an individual patient-level data meta-analysis (N=50 trials) using one-stage approach. We classified trials according to trial design: drug comparison (N=28), placebo-controlled (N=21) and BP-lowering intensity (N=8) trials. We fitted mixed models with fixed treatment effects and fixed time effect, random intercepts at trial and participant level, and a random slope for time at participant level. We adjusted for age, sex and baseline BP (except when used as stratification factor). We used likelihood ratio test and Akaike information criterion to compare models.

Results

This meta-analysis included 334,219 (42% women) participants. At baseline, mean age=65 (SD=9) years, among whom 18% were current smokers, 47% had cardiovascular disease, 29% had diabetes, and 73% were previously on BP-lowering medication. Participants had an average of 8 BP measurements over 4 years of mean follow-up. For drug comparison trials, mean differences (95% confidence interval) in systolic BP (SBP) and diastolic BP (DBP) between comparison arms were 1.3 (1.2 to 1.3) mmHg and 0.5 (0.5 to 0.5) mmHg, respectively; for placebo-controlled trials, the SBP and DBP differences were 4.2 (4.0 to 4.3) mmHg and 1.9 (1.9 to 2.0) mmHg, respectively; and for BP-lowering intensity trials, the SBP and DBP differences were 8.2 (8.0 to 8.4) mmHg and 3.7 (3.6 to 3.9) mmHg, respectively. However, BP reduction differed by duration of follow-up, type of trial. In particular, for placebo-controlled and BP-intensity trials, heterogeneity in BP reductions according to patient characteristics such as baseline BP, age, sex, prior CVD, diabetes and non-randomised anti-hypertensive use were observed.

Conclusion

This study shows the role of pharmacologic agents in effectively reducing long-term BP across individuals with a wide range of characteristics. The magnitude of BP reduction varied by several patient characteristics. This might have implications for investigation and explanation of any differential effects of BP treatment on major clinical outcomes.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): British Heart Foundation; NIHR Oxford Biomedial Research Centre

Self-rated health scores predict mortality among people with type 2 diabetes differently across three different country groupings: findings from the ADVANCE and ADVANCE-ON trials

AIMS

To explore whether there is a different strength of association between self-rated health and all-cause mortality in people with type 2 diabetes across three country groupings: nine countries grouped together as 'established market economies'; Asia; and Eastern Europe.

METHODS

The ADVANCE trial and its post-trial follow-up were used in this study, which included 11 140 people with type 2 diabetes from 20 countries, with a median follow-up of 9.9 years. Self-rated health was reported on a 0-100 visual analogue scale. Cox proportional hazard models were fitted to estimate the relationship between the visual analogue scale score and all-cause mortality, controlling for a range of demographic and clinical risk factors. Interaction terms were used to assess whether the association between the visual analogue scale score and mortality varied across country groupings.

RESULTS

The visual analogue scale score had different strengths of association with mortality in the three country groupings. A 10-point increase in visual analogue scale score was associated with a 15% (95% CI 12-18) lower mortality hazard in the established market economies, a 25% (95% CI 21-28) lower hazard in Asia, and an 8% (95% CI 3-13) lower hazard in Eastern Europe.

CONCLUSIONS

Self-rated health appears to predict 10-year all-cause mortality for people with type 2 diabetes worldwide, but this relationship varies across groups of countries.

Patients' understanding of cellulitis and views about how best to prevent recurrent episodes: mixed-methods study in primary and secondary care

BACKGROUND

Cellulitis is a common painful infection of the skin and underlying tissues that recurs in approximately one-third of cases. The only proven strategy to reduce the risk of recurrence is long-term, low-dose antibiotics. Given current concerns about antibiotic resistance and the pressure to reduce antibiotic prescribing, other prevention strategies are needed.

OBJECTIVES

To explore patients' views about cellulitis and different ways of preventing recurrent episodes.

METHODS

Adults aged ≥ 18 years with a history of first-episode or recurrent cellulitis were invited through primary care, hospitals and advertising to complete a survey, take part in an interview or both.

RESULTS

Thirty interviews were conducted between August 2016 and July 2017. Two hundred and forty surveys were completed (response rate 17%). Triangulation of quantitative and qualitative data showed that people who have had cellulitis have wide-ranging beliefs about what can cause cellulitis and are often unaware of risk of recurrence or potential strategies to prevent recurrence. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were more popular potential strategies than the use of compression stockings or long-term antibiotics. Participants expressed caution about long-term oral antibiotics, particularly those who had experienced only one episode of cellulitis.

CONCLUSIONS

People who have had cellulitis are keen to know about possible ways to prevent further episodes. Enhanced foot hygiene, applying emollients daily, exercise and losing weight were generally viewed to be more acceptable, feasible strategies than compression or antibiotics, but further research is needed to explore uptake and effectiveness in practice.

Healthcare-associated pneumonia: is there any reason to continue to utilize this label in 2019?

BACKGROUND

There is an ongoing controversy on the role of the healthcare-associated pneumonia (HCAP) label in the treatment of patients with pneumonia.

OBJECTIVE

To provide an update of the literature on patients meeting criteria for HCAP between 2014 and 2018.

SOURCES

The review is based on a systematic literature search using PubMed-Central full-text archive of biomedical and life sciences literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM).

CONTENT

Studies compared clinical characteristics of patients with HCAP and community-acquired pneumonia (CAP). HCAP patients were older and had a higher comorbidity. Mortality rates in HCAP varied from 5% to 33%, but seemed lower than those cited in the initial reports. Criteria behind the HCAP classification differed considerably within populations. Microbial patterns differed in that there was a higher incidence of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, and, to a lesser extent, enterobacteriaceae. Definitions and rates of multidrug-resistant (MDR) pneumonia also varied considerably. Broad-spectrum guideline-concordant treatment did not reduce mortality in four observational studies. The HCAP criteria performed poorly as a predictive tool to identify MDR pneumonia or pathogens not covered by treatment for CAP. A new score (Drug Resistance in Pneumonia, DRIP) outperformed HCAP in the prediction of MDR pathogens. Comorbidity and functional status, but not different microbial patterns, seem to account for increased mortality.

IMPLICATIONS

HCAP should no longer be used to identify patients at risk of MDR pathogens. The use of validated predictive scores along with implementation of de-escalation strategies and careful individual assessment of comorbidity and functional status seem superior strategies for clinical management.

Pharmacy informatics in multihospital health systems: Opportunities and challenges

PURPOSE

Challenges and opportunities in managing pharmacy-related technology in a multihospital health system are reviewed.

SUMMARY

With electronic medical record (EMR) implementations, pharmacy technology deployments, and increased numbers of hospitals merging into single health systems, opportunities and challenges for pharmacy informatics (PI) teams have grown. Pharmacy leaders must consider the implications of using technology in a multihospital health-system environment, as well as the impact of the health system's organizational structures on technology implementations and dedicated support teams. Common challenges in achieving EMR and other technology implementation and standardization initiatives in multihospital health systems include harmonization of practices across hospitals of various sizes and types and issues of platform compatibility and interoperability. PI teams must collaborate with information technology teams at the system level to identify practical strategies for making the best use of available resources to implement pharmacy automation and software to help pharmacists continue to provide safe and effective patient care. The organizational structures that affect informatics teams, pharmacy integration and standardization initiatives, formulary management practices, data management and analytics, and clinical decision support systems all must be areas of focus.

CONCLUSION

An integrated pharmacy enterprise can be well positioned to leverage operational efficiencies gained from appropriate use of technology to enhance patient care. Careful attention must be paid to the manner in which these systems are designed, implemented, and managed in order to make the best use of the technological resources used by the health system.

Identifying attributes associated with brown bear (Ursus arctos) road-crossing and roadkill sites

Habitat fragmentation caused by transportation infrastructure is an issue of growing concern worldwide. We show how secondary roads may affect landscape permeability for brown bears (Ursus arctos Linnaeus, 1758). We focused on identifying environmental variables that govern the selection of road-crossing zones by bears (crossing model). We also investigated whether variables that characterize road-crossing zones differ from those that are typical for bear–vehicle collision sites (collision model). The study area was located in north-central Slovakia. To identify road-crossing sites, we used the GPS fixes of 27 bears and identified 35 bear–vehicle collision sites from a different data set. We used mixed-effects logistic regression to model resource selection at road-crossing sites and to compare bear-crossing sites with bear-kill sites. The crossing model showed that the traffic volume with distance to forest and grassland were the most influential factors in bear selection of road-crossing sites. Results of the collision model indicated that successful road crossings by bears were located at different road sections from vehicle collisions, which differed by a traffic volume of 5000 vehicles/24 h. The outcomes of this study can facilitate improved mitigation measures on secondary roads.

The Treatment Effect of an ACE-Inhibitor Based Regimen with Perindopril in Relation to Beta-Blocker use in 29,463 Patients with Vascular Disease: a Combined Analysis of Individual Data of ADVANCE, EUROPA and PROGRESS Trials

INTRODUCTION

In everyday practice, angiotensin converting enzyme inhibitors and beta-blockers are cornerstone treatments in patients with (cardio-)vascular disease. Clear data that evaluate the effects of the combination of these agents on morbidity and mortality are lacking.

METHODS

In this retrospective pooled analysis of three large perindopril outcome trials (ADVANCE, EUROPA, PROGRESS), clinical outcomes were evaluated in 29,463 patients with vascular disease. Multivariate Cox regression analyses were performed in patients randomized to a perindopril-based regimen or placebo (treatment effect), and data were stratified according to background beta-blocker treatment. The primary endpoint was a composite of cardiovascular mortality, non-fatal myocardial infarction, and stroke.

RESULTS

The cumulative incidence of the primary endpoint over mean follow-up of 4.0 years (Sd 1.0) was significantly lower in the beta-blocker/perindopril group (9.6%; 545/5700 patients) as compared to beta-blocker/placebo (11.8%; 676/5718 patients) (p < 0.01). Adding perindopril to existing beta-blocker treatment reduced the relative risk of the primary endpoint by 20% (hazard ratio (HR) 0.80; 95% confidence interval (CI) 0.71-0.90), non-fatal myocardial infarction by 23% (HR 0.77; 95% CI 0.65-0.91), and all-cause mortality by 22% (HR 0.78; 95% CI 0.68-0.88) as compared to placebo. Significant treatment benefit was not observed for stroke (HR 0.93; 95% CI 0.75-1.15). Significance was maintained for the primary endpoint and cardiovascular endpoints when data were further stratified by baseline hypertension. However, the mortality benefit was only observed in patients with hypertension with background beta-blocker use.

CONCLUSIONS

These data suggest that the beneficial cardioprotective effects of perindopril treatment are additive to the background beta-blockers use.

Low active loading of cargo into engineered extracellular vesicles results in inefficient miRNA mimic delivery

Extracellular vesicles (EVs) hold great potential as novel systems for nucleic acid delivery due to their natural composition. Our goal was to load EVs with microRNA that are synthesized by the cells that produce the EVs. HEK293T cells were engineered to produce EVs expressing a lysosomal associated membrane, Lamp2a fusion protein. The gene encoding pre-miR-199a was inserted into an artificial intron of the Lamp2a fusion protein. The TAT peptide/HIV-1 transactivation response (TAR) RNA interacting peptide was exploited to enhance the EV loading of the pre-miR-199a containing a modified TAR RNA loop. Computational modeling demonstrated a stable interaction between the modified pre-miR-199a loop and TAT peptide. EMSA gel shift, recombinant Dicer processing and luciferase binding assays confirmed the binding, processing and functionality of the modified pre-miR-199a. The TAT-TAR interaction enhanced the loading of the miR-199a into EVs by 65-fold. Endogenously loaded EVs were ineffective at delivering active miR-199a-3p therapeutic to recipient SK-Hep1 cells. While the low degree of miRNA loading into EVs through this approach resulted in inefficient distribution of RNA cargo into recipient cells, the TAT TAR strategy to load miRNA into EVs may be valuable in other drug delivery approaches involving miRNA mimics or other hairpin containing RNAs.

Comprehensive toxicity and immunogenicity studies reveal minimal effects in mice following sustained dosing of extracellular vesicles derived from HEK293T cells

Extracellular vesicles (EVs) are under evaluation as therapeutics or as vehicles for drug delivery. Preclinical studies of EVs often use mice or other animal models to assess efficacy and disposition. However, as most EVs under evaluation are derived from human cells, they may elicit immune responses which may contribute to toxicities or enhanced EV clearance. Furthermore, EVs from different cell sources or EVs comprising various cargo may differ with respect to immunogenicity or toxicity. To assess EV-induced immune response and toxicity, we dosed C57BL/6 mice with EVs intravenously and intraperitoneally for 3 weeks. EVs were harvested from wild type or engineered HEK293T cells which were modified to produce EVs loaded with miR-199a-3p and chimeric proteins. Blood was collected to assess hematology, blood chemistry, and immune markers. Spleen cells were immunophenotyped, and tissues were harvested for gross necropsy and histopathological examination. No signs of toxicity were observed, and minimal evidence of changes in immune markers were noted in mice dosed with engineered, but not with wild type EVs. This study provides a framework for assessment of immunogenicity and toxicity that will be required as EVs from varying cell sources are tested within numerous animal models and eventually in humans.

The impact of level of education on vascular events and mortality in patients with type 2 diabetes mellitus: Results from the ADVANCE study

AIMS

The relationship between educational level and the risk of all-cause mortality is well established, whereas the association with vascular events in individuals with type 2 diabetes is not well described. Any association may reflect a link with common cardiovascular or lifestyle-based risk factors.

METHODS

The relationships between the highest level of educational attainment and major cardiovascular events, microvascular complications and all-cause mortality were explored in a cohort of 11,140 individuals with type 2 diabetes. Completion of formal education before the age of 16 was categorized as a low level of education. Regional differences between Asia, East Europe and Established Market Economies were also assessed.

RESULTS

During a median of 5years of follow up, 1031 (9%) patients died, 1147 (10%) experienced a major cardiovascular event and 1136 (10%) a microvascular event. After adjustment for baseline characteristics and risk factors, individuals with lower education had an increased risk of cardiovascular events (hazard ratio (HR) 1.31, 95% CI 1.16-1.48, p<0.0001), microvascular events (HR 1.23, 95% CI 1.08-1.39, p=0.0013) and all-cause mortality (HR 1.34, 95% CI 1.18-1.52, p<0.0001). In regional analyses the increased risk of studied outcomes associated with lower education was weakest in Established Market Economies and strongest in East Europe.

CONCLUSIONS

A low level of education is associated with an increased risk of vascular events and death in patients with type 2 diabetes, independently of common lifestyle associated cardiovascular risk factors. The effect size varies between geographical regions.

Inaccurate risk perceptions contribute to treatment gaps in secondary prevention of cardiovascular disease

BACKGROUND

All patients with cardiovascular disease (CVD) are at high risk of recurrent events. Despite strong evidence, large treatment gaps exist in CVD secondary prevention. We hypothesise that patients' self-perception and general practitioner's (GP) assessment of future cardiovascular (CV) risk may influence secondary prevention behaviours.

AIM

To examine in patients with known CVD the perceived risk of future CV events and its relationship with use of secondary prevention medications and risk factor control.

METHODS

We examined patient and practitioner's perceived risk and its relationship with the uptake of secondary prevention recommendations in adults with CVD participating in the Australian Hypertension and Absolute Risk Study.

RESULTS

Among the 1453 participants, only 11% reported having a high absolute risk and 29% reported high relative risk of recurrent events. The GP categorised only 30% as having a 5-year risk ≥15%. After adjusting for covariates, hospitalisation within the preceding 12 months was the only significant predictor of patients' accurate risk perception. Conventional CV risk factors were predictive of the GP's risk estimates. Patients who accurately understood their risk reported higher smoking cessation rates (7 vs 3%, P = 0.003) and greater use of antiplatelet, blood pressure lowering therapy and statins (P ≤ 0.01). However, there was no relationship between GP's risk perception and secondary prevention treatments.

CONCLUSION

Both patients and GP have optimistic bias and underestimate the risk of future CV events. Patients' accurate self-perception, but not GP risk perception, was associated with improved secondary preventative behaviours. This suggests that helping patients to understand their risk may influence their motivation towards secondary prevention. Providing support to GP or programmes to help patients better understand their risks could have potential benefit on secondary prevention behaviours.

A functional mechanistic study of the effect of emollients on the structure and function of the skin barrier

BACKGROUND

Preventing relapses of atopic dermatitis (AD) through the regular use of topical products to repair the skin barrier defect is an emerging concept. It is still unclear if some commonly used emollients exert a positive effect on the skin barrier.

OBJECTIVES

To determine the skin barrier effects of emollients commonly prescribed in the U.K.

MATERIALS AND METHODS

Two cohorts of volunteers with quiescent AD undertook observer-blind forearm-controlled studies. The first cohort (18 volunteers) treated the volar side of one forearm with two fingertip units of Doublebase^™ gel twice daily for 4 weeks. The second cohort (19 volunteers) undertook the same regimen using Diprobase^® cream. Transepidermal water loss (TEWL), stratum corneum integrity and hydration, skin surface pH and redness were determined at the test sites before and after treatment.

RESULTS

Neither Diprobase^® cream nor Doublebase^™ gel significantly affected the underlying skin barrier function. Both emollients were associated with significantly increased skin surface pH immediately after application (by 0·8 ± 0·19 and 1·0 ± 0·18 units, respectively), and no erythema. Diprobase^® cream artificially and transiently (6 h) improved permeability barrier function by 2·9-3·1 g m^-2  h^-1 TEWL and increased skin hydration by 6·0-6·2 units. Doublebase^™ gel, containing humectants, was associated with a greater (between 10·1 and 13·0 units during the first 6 h) and more sustained increase in hydration, lasting more than 12 h following repeated use.

CONCLUSIONS

Diprobase^® cream and Doublebase^™ gel are not associated with skin barrier harm and appear to be appropriate for AD treatment. While displaying emollient properties, neither formulation displayed an ability to actively improve sustained skin barrier function.

Variations in all Cause and Cardiovascular Mortality by Country of Birth in Scotland, 1997-2003

Background and Aims

Country of birth provides a proxy for ethnic group for recent migrants. Major differences in mortality by country of birth have been demonstrated in England and Wales, but similar published data for Scotland are lacking. We aimed to examine variations in mortality by country of birth for Scottish residents.

Methods

We calculated standardised mortality ratios by country of birth for Scottish residents aged 25 years and over between January 1997 and March 2003.

Results and Conclusion

Comparisons with England and Wales showed high allcause, coronary heart disease (CHD) and stroke mortality among Scottish residents born in Scotland, Northern Ireland, the Republic of Ireland, India and Hong Kong. However, most country of birth groups had similar or lower mortality than the Scottish born. These are the first data on mortality by country of birth in Scotland and they demonstrate major variations. Comparisons within the Scottish population might be interpreted as reassuring, since they do not show the excesses in CHD mortality by country of birth reported in England and Wales. However, the use of England and Wales as a comparison group shows a substantial excess of CHD risk among South Asians in Scotland, comparable to that reported in England and Wales.

Prediction of 10-year vascular risk in patients with diabetes: the AD-ON risk score

AIMS

To formulate a combined cardiovascular risk score in diabetes that could be useful both to physicians and healthcare funders.

METHODS

Data were derived from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation Observational (ADVANCE-ON) study, a randomized controlled trial (mean duration 5 years) with a post-randomization follow-up (mean 4.9 years), that included 11 140 high-risk patients with diabetes. The outcome analysed was the occurrence of either fatal or non-fatal macrovascular or renal disease. A Cox regression model was used to determine weightings in the risk score. The resultant score was recalibrated to each of three major global regions, as covered by the ADVANCE-ON study.

RESULTS

Over a median of 9.9 years, 1145 patients experienced at least one component of the combined outcome event. The resultant score, the AD-ON risk score, incorporated 13 demographic or clinical variables. Its discrimination was modest [c-statistic = 0.668 (95% confidence interval 0.651, 0.685)] but its calibration was excellent (predicted and observed risks coincided well, within disparate global regions). In terms of the integrated discrimination improvement index, its performance was marginally superior, over a 10-year risk horizon, to existing risk scores in clinical use, from a restricted version of the same data, for macrovascular and renal disease separately.

CONCLUSIONS

The AD-ON risk score has advantages over the existing vascular risk scores in diabetes that used data from the original ADVANCE trial, which treat macrovascular and renal diseases separately. These advantages include its simplicity of use and global application.

Use of antidiabetic and antidepressant drugs is associated with increased risk of myocardial infarction: a nationwide register study

AIMS

To explore the gender- and age-specific risk of developing a first myocardial infarction in people treated with antidiabetic and/or antidepressant drugs compared with people with no pharmaceutical treatment for diabetes or depression.

METHODS

A cohort of all Swedish residents aged 45-84 years (n = 4 083 719) was followed for a period of 3 years. Data were derived from three nationwide registers. The prescription and dispensing of antidiabetic and antidepressant drugs were used as markers of disease. All study subjects were reallocated according to treatment and the treatment categories were updated every year. Data were analysed using a Cox regression model with a time-dependent variable. The outcome of interest was first fatal or non-fatal myocardial infarction.

RESULTS

During follow-up, 42 840 people had a first myocardial infarction, 3511 of which were fatal. Women aged 45-64 years, receiving both antidiabetic and antidepressant drugs had a hazard ratio for myocardial infarction of 7.4 (95% CI 6.3-8.6) compared with women receiving neither. The corresponding hazard ratio for men was 3.1 (95% CI 2.8-3.6).

CONCLUSIONS

The combined use of antidiabetic and antidepressant drugs was associated with a higher risk of myocardial infarction compared with use of either group of drugs alone. The increase in relative risk was greater in middle-aged women than in middle-aged men.