Performance of drug-coated balloons in coronary and below-the-knee arteries: Anatomical, physiological and pathological considerations

Below-the-knee (infrapopliteal) atherosclerotic disease, which presents as chronic limb-threatening ischemia (CLTI) in nearly 50% of patients, represents a treatment challenge when it comes to the endovascular intervention arm of management. Due to reduced tissue perfusion, patients usually experience pain at rest and atrophic changes correlated to the extent of the compromised perfusion. Unfortunately, the prognosis remains unsatisfactory with 30% of patients requiring major amputation and a mortality rate of 25% within 1 year. To date, randomized multicentre trials of endovascular intervention have shown that drug-eluting stents (DES) increase patency rate and lower target lesion revascularization rate compared to plain balloon angioplasty and bare-metal stents. The majority of these trials recruited patients with focal infrapopliteal lesions, while most patients requiring endovascular intervention have complex and diffuse atherosclerotic disease. Moreover, due to the nature of the infrapopliteal arteries, the use of long DES is limited. Following recent results of drug-coated balloons (DCBs) in the treatment of femoropopliteal and coronary arteries, it was hoped that similar effective results would be achieved in the infrapopliteal arteries. In reality, multicentre trials have failed to support the proposed hypothesis and no advantage was found in using DCBs in comparison to plain balloon angioplasty. This review aims to explore anatomical, physiological and pathological differences between lesions of the infrapopliteal and coronary arteries to explain the differences in outcome when using DCBs.

Plasma-activated liquid as a potential decontaminant in healthcare: assessment of antibacterial activity and use with cleaning cloths

BACKGROUND

Cold air plasma (CAP) can generate plasma-activated liquids (PALs) with high concentrations of reactive oxygen (ROS) and nitrogen species (RNS), e.g., nitrites, with antimicrobial properties.

AIM

We investigated the concentrations of ROS and RNS in saline PAL. We assessed planktonic bacterial inactivation by PAL and the decontamination of contaminated cleaning cloths.

METHODS

Phosphate-buffered saline (PBS) was treated with an air-driven CAP jet for 90 or 300 s to generate PAL. The ROS and RNS were measured using quantitative fluorescent (2,7-dichlorofluorescin diacetate) and colourimetric (Greiss) assays. Isolates of MRSA and Escherichia coli were incubated in PAL overnight and inactivation measured through colony forming unit (cfu) assays. Sections of cleaning cloths were incubated with MRSA and E. coli, and treated with PAL for 1 h. Bacterial inactivation was measured through resazurin reduction assays.

RESULTS

Nitrites increased from 0.1 μM in untreated PBS to 49.1 μM and to 94.0 μM in 90- and 300-s CAP-treated PAL, respectively. ROS increased from 30 μM in untreated PBS to 75 μM and to 103 μM in 90- and 300-s CAP-treated PAL, respectively. 90-s PAL reduced MRSA and E. coli viability (P<0.05) and 300-s PAL resulted in more than a 7-log reduction of both. One-hour treatment of contaminated cleaning cloths in PAL resulted in a 55% and 73% reduction in viable MRSA and E. coli, respectively (P<0.05).

CONCLUSION

Inactivation of planktonic bacteria correlated with ROS and RNS concentrations. PAL reduced bacteria contaminated cleaning cloths. PAL has potential as a hospital disinfectant, including cleaning cloths.

Realtime monitoring of thrombus formation in vivo using a self-reporting vascular access graft

BACKGROUND

Chronic kidney disease (CKD) affects 10% of the global population costing over a hundred billion dollars per annum and leading to increased risk of cardiovascular disease. Many patients with CKD require regular haemodialyses. Synthetic arteriovenous grafts (AVG) are increasingly used to provide rapid vascular connection for dialysis. Initially, they have excellent patency rates but are critically limited by neointimal hyperplasia at the venous anastomosis, which drives subsequent thrombosis, graft failure and death.

METHODS

Here, we describe a system in which electrical impedance spectroscopy sensors are incorporated circumferentially into the wall of a synthetic arteriovenous graft. This is combined with an implantable radiotelemetry system for data transmission outside the patient. The system was tested using monolayers of endothelial and smooth muscle cells as well as swine blood and clots with explanted human carotid artery plaques. Sensor testing was then performed in vitro and the device was implanted in vivo in female swine.

RESULTS

The device can wirelessly report the accumulation of biological material, both cells and blood. Differences are also detected when comparing controls with pathological atheroma. In swine differences between blockage formation in a graft were remotely obtained and wireless reported.

CONCLUSIONS

Combining electrical impedance spectroscopy and an implantable radiotelemetry system enables graft surveillance. This has the potential to be used for early detection of venous stenosis and blood clot formation in real-time in vivo. In principle, the concept could apply to other cardiovascular diseases and vascular implantable devices.

Hypertension & dementia: Pathophysiology & potential utility of antihypertensives in reducing disease burden

Dementia is a common cause of disability and dependency among the elderly due to its progressive neurodegenerative nature. As there is currently no curative therapy, it is of major importance to identify new ways to reduce its prevalence. Hypertension is recognised as a modifiable risk factor for dementia, particularly for the two most common subtypes; vascular dementia (VaD) and Alzheimer's disease (AD). From the current literature, identified through a comprehensive literature search of PubMed and Cochrane Library, this review aims to establish the stage in adulthood when hypertension becomes a risk for cognitive decline and dementia, and whether antihypertensive treatment is effective as a preventative therapy. Observational studies generally found hypertension in mid-life (age 45-64) to be correlated with an increased risk of cognitive decline and dementia incidence, including both VaD and AD. Hypertension manifesting in late life (age ≥ 65) was demonstrated to be less of a risk, to the extent that incidences of high blood pressure (BP) in the very elderly (age ≥ 75) may even be related to reduced incidence of dementias. Despite the evidence linking hypertension to dementia, there were conflicting findings as to whether the use of antihypertensives was beneficial for its prevention and this conflicting evidence and inconsistent results could be due to the methodological differences between the reviewed observational and randomised controlled trials. Furthermore, dihydropyridine calcium channel blockers and potassium-sparing diuretics were proposed to have neuroprotective properties in addition to BP lowering. Overall, if antihypertensives are confirmed to be beneficial by larger-scale homogenous trials with longer follow-up durations, treatment of hypertension, particularly in mid-life, could be an effective strategy to considerably lower the prevalence of dementia. Furthermore, greater clarification of the neuroprotective properties that some antihypertensives possess will allow for better clinical practice guidance on the choice of antihypertensive class for both BP lowering and dementia prevention.

Four Models of Wastewater-Based Surveillance for SARS-CoV-2 in Jail Settings: How Monitoring Wastewater Complements Individual Screening

Objective

To describe four unique models of implementing Wastewater Based Surveillance (WBS) for SARS-CoV-2 in jails of graduated sizes and differing architectural designs.

Methods

This study summarizes how jails of Cook County (Illinois, average daily population [ADP] 6000), Fulton County (Georgia, ADP 3000, Washington DC (ADP 1600) and Middlesex County (Massachusetts, ADP 875) initiated WBS between 2020 and 2023.

Results

Positive signal for SARS-CoV-2 via WBS can herald new onset of infection in a previously uninfected housing unit of a jail. Challenges in implementing WBS included political will and realized value, funding, understanding of the building architecture, and the need for granularity in the findings.

Conclusions

WBS has been effective for detecting outbreaks of SARS-CoV-2 in differing sized jails, both those with dorm-based and cell-based architectural design.

Policy implications

Given its effectiveness in monitoring SARS-CoV-2, WBS provides a model for population-based surveillance in carceral facilities for future infectious disease outbreaks.

The application of human reliability analysis to carpal tunnel decompression

INTRODUCTION

Many surgical procedures are prone to human error, particularly in the learning phase of skills acquisition. Task standardisation has been suggested as an approach to reducing errors, but it fails to account for the human factors associated with learning. Human reliability analysis (HRA) is a structured approach to assess human error during surgery. This study used HRA methodologies to examine skills acquisition associated with carpal tunnel decompression.

METHODS

The individual steps or subtasks required to complete a carpal tunnel decompression were identified using hierarchical task analysis (HTA). The systematic human error reduction and prediction approach (SHERPA) was carried out by consensus of subject matter experts. This identified the potential human errors at each subgoal, the level of risk associated with each task and how these potential errors could be prevented.

RESULTS

Carpal tunnel decompression was broken down into 46 subtasks, of which 21 (45%) were medium risk and 25 (55%) were low risk. Of the 46 subtasks, 4 (9%) were assigned high probability and 18 (39%) were assigned medium probability. High probability errors (>1/50 cases) included selecting incorrect tourniquet size, failure to infiltrate local anaesthetic in a proximal-to-distal direction and completion of the World Health Organization (WHO) surgical sign-out. Three (6%) of the subtasks were assigned high criticality, which included failure to aspirate before anaesthetic injection, whereas 21 (45%) were assigned medium criticality. Remedial strategies for each potential error were devised.

CONCLUSIONS

The use of HRA techniques provides surgeons with a platform to identify critical steps that are prone to error. This approach may improve surgical training and enhance patient safety.

10 ASSISTED DECISION-MAKING, THE OLDER ADULT, AND LOCUS OF CONTROL

Background

The Assisted Decision-making (Capacity) Act (ADMCA) (2015) will be fully commenced later in 2022. At its core, the legislation seeks to encourage the older adult to express their will and preferences regarding their healthcare decisions. The legislation removes healthcare decision-making powers from family members and healthcare professionals unless expressly nominated by the patient to make decisions on their behalf. However, a lack of clarity and professional uncertainty pervades this area in Ireland that is mirrored in the global research.

Methods

This qualitative study comprised 5 focus groups of hospital discharge coordinators in the South East of Ireland. It sought to examine the issues that exist for the older patient when they return home following a hospital stay. It also examined who really has responsibility for healthcare decision-making and who is responsible for providing the care? Thematic analysis was used to analyse the findings.

Results

The findings revealed a significant incongruence of beliefs among patients, family members and healthcare professionals when it comes to locus of control.

Conclusion

This study’s findings on locus of control – both in terms of where the discharge coordinators believe the locus is, and where they believe the families think it is - are the first of their kind in Irish Healthcare and are therefore highly significant in several respects. The substantive areas of disagreement in beliefs among the groups, represent real barriers to supporting ADMCA going forward.

954 Sarcoidosis Mimicking Progression of Melanoma: A Case Report

A 78-year-old lady with a history of malignant melanoma on the dorsal aspect of her left foot, presented with a new fluorodeoxyglucose positron emission tomography (FDG-PET) avid lesion in her left fibular head.

The patient had been diagnosed eight months previously with a 5.1mm Breslow thickness invasive melanoma. Following initial diagnosis, she underwent a wide local excision and sentinel lymph node biopsy (SLN). The melanoma was completely excised and SLN was negative for malignancy.

Postoperatively, she underwent radiological staging with computed tomography scans (CT) of her thorax, abdomen, and pelvis. This showed scattered pulmonary nodules, and multiple indeterminate liver lesions. A PET scan was then performed, which showed an expansile, FDG-avid, lytic lesion in the left fibular head, suspicious for bone metastasis. Following discussion at the multidisciplinary team meeting, the patient underwent an open biopsy of the fibular head. Histology revealed non-necrotising epitheloid granulomata without evidence of malignancy. Ziehl-Neelsen and periodic acid Schiff stains were negative. The findings were suggestive of sarcoidosis.

The patient revealed she had a previous diagnosis of pulmonary sarcoidosis 25 years prior, however, had no known extrapulmonary disease and was not attending a specialist. The pulmonary findings on CT were consistent with sarcoidosis.

Sarcoidosis is a systemic inflammatory disease characterised by the development of non-caseating granulomata which typically affect the lungs and lymph nodes but can affect multiple organ systems. This case highlights the diagnostic uncertainty of an FDG-avid lesion on PET, necessitating diagnostic biopsy. Sarcoidosis is an uncommon but possible differential in this setting.

An intricate interplay between stent drug dose and release rate dictates arterial restenosis

Since the introduction of percutaneous coronary intervention (PCI) for the treatment of obstructive coronary artery disease (CAD), patient outcomes have progressively improved. Drug eluting stents (DES) that employ anti-proliferative drugs to limit excess tissue growth following stent deployment have proved revolutionary. However, restenosis and a need for repeat revascularisation still occurs after DES use. Over the last few years, computational models have emerged that detail restenosis following the deployment of a bare metal stent (BMS), focusing primarily on contributions from mechanics and fluid dynamics. However, none of the existing models adequately account for spatiotemporal delivery of drug and the influence of this on the cellular processes that drive restenosis. In an attempt to fill this void, a novel continuum restenosis model coupled with spatiotemporal drug delivery is presented. Our results indicate that the severity and time-course of restenosis is critically dependent on the drug delivery strategy. Specifically, we uncover an intricate interplay between initial drug loading, drug release rate and restenosis, indicating that it is not sufficient to simply ramp-up the drug dose or prolong the time course of drug release to improve stent efficacy. Our model also shows that the level of stent over-expansion and stent design features, such as inter-strut spacing and strut thickness, influence restenosis development, in agreement with trends observed in experimental and clinical studies. Moreover, other critical aspects of the model which dictate restenosis, including the drug binding site density are investigated, where comparisons are made between approaches which assume this to be either constant or proportional to the number of smooth muscle cells (SMCs). Taken together, our results highlight the necessity of incorporating these aspects of drug delivery in the pursuit of optimal DES design.

Impact of healthcare-associated infection on length of stay

BACKGROUND

Increased length of stay (LOS) for patients is an important measure of the burden of healthcare-associated infection (HAI).

AIM

To estimate the excess LOS attributable to HAI.

METHODS

This was a one-year prospective incidence study of HAI observed in one teaching hospital and one general hospital in NHS Scotland as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. All adult inpatients with an overnight stay were included. HAI was diagnosed using European Centres for Disease Prevention and Control definitions. A multi-state model was used to account for the time-varying nature of HAI and the competing risks of death and discharge.

FINDINGS

The excess LOS attributable to HAI was 7.8 days (95% confidence interval (CI): 5.7-9.9). Median LOS for HAI patients was 30 days and for non-HAI patients was 3 days. Using a simple comparison of duration of hospital stay for HAI cases and non-cases would overestimate the excess LOS by 3.5 times (27 days compared with 7.8 days). The greatest impact on LOS was due to pneumonia (16.3 days; 95% CI: 7.5-25.2), bloodstream infections (11.4 days; 5.8-17.0) and surgical site infection (SSI) (9.8 days; 4.5-15.0). It is estimated that 58,000 bed-days are occupied due to HAI annually.

CONCLUSION

A reduction of 10% in HAI incidence could make 5800 bed-days available. These could be used to treat 1706 elective patients in Scotland annually and help reduce the number of patients awaiting planned treatment. This study has important implications for investment decisions in infection prevention and control interventions locally, nationally, and internationally.

Bed-days and costs associated with the inpatient burden of healthcare-associated infection in the UK

BACKGROUND

Healthcare-associated infection (HAI) is associated with increased morbidity and mortality resulting in excess costs.

AIM

To investigate the impact of all types of HAI on the inpatient cost of HAI using different approaches.

METHODS

The incidence, types of HAI, and excess length of stay were estimated using data collected as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. Scottish NHS reference costs were used to estimate unit costs for bed-days. Variable (cash) costs associated with infection prevention and control (IPC) measures and treatment were calculated for each HAI type and overall. The inpatient cost of HAI is presented in terms of bed-days lost, bed-day costs, and cash costs.

FINDINGS

In Scotland 58,010 (95% confidence interval: 41,730-74,840) bed-days were estimated to be lost to HAI during 2018/19, costing £46.4 million (19m-129m). The total annual cost in the UK is estimated to be £774 million (328m-2,192m). Bloodstream infection and pneumonia were the most costly HAI types per case. Cash costs are a small proportion of the total cost of HAI, contributing 2.4% of total costs.

CONCLUSION

Reliable estimates of the cost burden of HAI management are important for assessing the cost-effectiveness of IPC programmes. This unique study presents robust economic data, demonstrating that HAI remains a burden to the UK NHS and bed-days capture the majority of inpatient costs. These findings can be used to inform the economic evaluation and decision analytic modelling of competing IPC programmes at local and national level.

Epidemiology of healthcare-associated infection reported from a hospital-wide incidence study: considerations for infection prevention and control planning

BACKGROUND

The measure of disease frequency most widely used to report healthcare-associated infection (HAI) is the point-prevalence survey. Incidence studies are rarely performed due to time and cost constraints; they show which patients are affected by HAI, when and where, and inform planning and design of infection prevention and control (IPC) measures.

AIM

To determine the epidemiology of HAI within a general and a teaching hospital in Scotland.

METHODS

A prospective observational incidence study was undertaken for one year from April 2018 using data collected as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. A novel, robust approach was undertaken, using record linkage to national administrative data to provide full admission and discharge information. Cases were recorded if they met international HAI definitions.

FINDINGS

Incidence of HAI for the combined hospitals was 250 HAI cases per 100,000 acute occupied bed-days (AOBD). Highest frequency was in urinary tract (51.2 per 100,000 AOBD), bloodstream (44.7), and lower respiratory tract infection (42.2). The most frequently reported organisms were Escherichia coli, Staphylococcus aureus, and norovirus. Incidence of HAI was higher in older people and emergency cases. There was an increase in the rate of HAI in summer months (pneumonia, respiratory, surgical, and gastrointestinal infection) and in winter months norovirus gastrointestinal infection (P < 0.0001). The highest incidence specialties were intensive care, renal medicine, and cardiothoracic surgery. HAI occurred at a median of 9 days (interquartile range: 4-19) after admission. Incidence data were extrapolated to provide an annual national estimate of HAI in NHS Scotland of 7437 (95% confidence interval: 7021-7849) cases.

CONCLUSION

This study provides a unique overview of incidence of HAI and identifies the burden of HAI at the national level for the first time. Understanding the incidence in different clinical settings, at different times, will allow targeting of IPC measures to those patients who would benefit the most.

Personalized infection prevention and control: identifying patients at risk of healthcare-associated infection

BACKGROUND

Few healthcare-associated infection (HAI) studies focus on risk of HAI at the point of admission. Understanding this will enable planning and management of care with infection prevention at the heart of the patient journey from the point of admission.

AIM

To determine intrinsic characteristics of patients at hospital admission and extrinsic events, during the two years preceding admission, that increase risk of developing HAI.

METHODS

An incidence survey of adults within two hospitals in NHS Scotland was undertaken for one year in 2018/19 as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. The primary outcome measure was developing any HAI using recognized case definitions. The cohort was derived from routine hospital episode data and linkage to community dispensed prescribing data.

FINDINGS

The risk factors present on admission observed as being the most significant for the acquisition of HAI were: being treated in a teaching hospital, increasing age, comorbidities of cancer, cardiovascular disease, chronic renal failure and diabetes; and emergency admission. Relative risk of developing HAI increased with intensive care unit, high-dependency unit, and surgical specialties, and surgery <30 days before admission and a total length of stay of >30 days in the two years to admission.

CONCLUSION

Targeting patients at risk of HAI from the point of admission maximizes the potential for prevention, especially when extrinsic risk factors are known and managed. This study proposes a new approach to infection prevention and control (IPC), identifying those patients at greatest risk of developing a particular type of HAI who might be potential candidates for personalized IPC interventions.

POS0278 A MULTICENTER, OBSERVATIONAL, EXTENSION STUDY EVALUATING THE SAFETY, TOLERABILITY, AND EFFICACY OF A SINGLE LORECIVIVINT INJECTION IN KNEE OA SUBJECTS

Background:

Lorecivivint (LOR), a novel intra-articular (IA) CLK2/DYRK1A inhibitor that modulates the Wnt pathway, is in development as a knee osteoarthritis (OA) treatment.

Objectives:

Subjects from two consecutive Phase 2 trials were followed up in a 5-year, pooled, observational study that evaluated the safety and exploratory efficacy of a single LOR injection that was previously administered into the target knee joint of subjects with moderate to severe knee OA. The study was terminated in its third year, as relevant long-term safety information became limited in the absence of repeated LOR administration. The primary objective evaluated the incidence of serious adverse events (SAEs). Safety data for all doses and a post hoc efficacy analysis for the pivotal dose (0.07 mg LOR) are reported.

Methods:

This was a Phase 3, multicenter, observational, extension study of completer subjects (OA-05; NCT02951026) from two Phase 2 trials of LOR: a 12-month Phase 2a trial (OA-02; NCT02536833)1 and a 6-month Phase 2b trial (OA-04; NCT03122860)2. Subjects received a single LOR or control (placebo or vehicle) injection at their parent-study baseline visit (OA-02 or OA-04 Visit 0 in this analysis). Pooled data from clinic visits at 6, 12, 24, and 36 months contributed to the extension-study (OA-05) analysis. SAEs, knee-related adverse events (AEs), and AEs of newly diagnosed conditions requiring treatment were collected as safety outcomes. Efficacy was assessed by target knee WOMAC Pain and Function subscores and radiographic medial joint space width (mJSW). A post hoc analysis was performed for 0.07 mg LOR versus control to assess responses in a subject subgroup (unilateral symptoms, no widespread pain, 18-month post-injection radiograph at study termination). Baseline-adjusted ANCOVA was performed using data from both the current and parent studies at 0, 3, 6, 12, and 18 months.

Results:

Of 703 subjects, 119 (17%) subjects discontinued prior to study termination. Subjects had a mean age of 60.7 years and mean BMI of 29.1 kg/m2, and 61% were female. The majority of subjects had KL 3 (61.2%) OA. The safety analysis set included 495 LOR-treated subjects and 208 control subjects. There were 169 AEs reported by 110 [15.6%] subjects. Four AEs were considered to be related to study drug and were reported by 3 (0.6%) subjects across LOR groups; no subjects withdrew from the study due to a treatment-related AE. The most common AEs were osteoarthritis (28 [4.0%] subjects) and arthralgia (25 [3.6%] subjects); incidence was similar between LOR and control groups. During the study, 68 SAEs were reported by 38 (5.4%) subjects, and no SAEs were considered to be related to treatment by investigator. One death occurred in the control group. Post hoc efficacy analyses demonstrated that subjects in the 0.07 mg LOR group (n=59) showed greater improvements from baseline in both WOMAC Pain and Function at 6 and 12 months versus subjects in the control group (n=70) (Figure 1; Day 0):

6 months:Pain: -8.16, 95% CI [-15.60, -0.71], P=0.032

Function: -9.47, 95% CI [-17.09, -1.84], P=0.015

12 months:Pain: -8.51, 95% CI [-15.17, -1.85], P=0.013

Function: -9.62, 95% CI [-16.83, -2.42], P=0.009

No mJSW progression was observed in any group over 18 months.

Limitations to this analysis include 1) subjects from LOR and control groups were “completers,” therefore, more likely to be responders, and 2) subjects could have been on any medication or treatment in the extension study.

Conclusion:

From these data, LOR appeared to be safe and well tolerated. A post hoc-analyzed subset of completer subjects treated with a single 0.07 mg LOR injection reported durable symptom improvements in WOMAC Pain and Function for up to at least 12 months versus control subjects.

References:

[1]Yazici Y, et al. Arthritis Rheumatol. 2020.

[2]Yazici Y, et al. ACR meeting. 2019. Abstract L03.

Disclosure of Interests:

Ismail Simsek Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Christopher Swearingen Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Heli Ghandehari Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Sarah Kennedy Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Jeyanesh Tambiah Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Nebojsa Skrepnik Consultant of: Pfizer, Regeneron, Orthofix, Grant/research support from: Samumed, LLC

Do we really understand how drug eluted from stents modulates arterial healing?

The advent of drug-eluting stents (DES) has revolutionised the treatment of coronary artery disease. These devices, coated with anti-proliferative drugs, are deployed into stenosed or occluded vessels, compressing the plaque to restore natural blood flow, whilst simultaneously combating the evolution of restenotic tissue. Since the development of the first stent, extensive research has investigated how further advancements in stent technology can improve patient outcome. Mathematical and computational modelling has featured heavily, with models focussing on structural mechanics, computational fluid dynamics, drug elution kinetics and subsequent binding within the arterial wall; often considered separately. Smooth Muscle Cell (SMC) proliferation and neointimal growth are key features of the healing process following stent deployment. However, models which depict the action of drug on these processes are lacking. In this article, we start by reviewing current models of cell growth, which predominantly emanate from cancer research, and available published data on SMC proliferation, before presenting a series of mathematical models of varying complexity to detail the action of drug on SMC growth in vitro. Our results highlight that, at least for Sodium Salicylate and Paclitaxel, the current state-of-the-art nonlinear saturable binding model is incapable of capturing the proliferative response of SMCs across a range of drug doses and exposure times. Our findings potentially have important implications on the interpretation of current computational models and their future use to optimise and control drug release from DES and drug-coated balloons.

Epidemiology of and risk factors for mortality due to carbapenemase-producing organisms (CPO) in healthcare facilities

BACKGROUND

Carbapenemase-producing organisms (CPO) have been largely responsible for the extensive spread of carbapenem resistance, and their prevalence is increasing in many parts of the world.

AIM

To evaluate clinical and molecular epidemiology and mortality associated with CPO among patients.

METHODS

All CPO from clinical and long-term healthcare surveillance cultures across Scotland in 2003-2017 were reviewed retrospectively. Polymerase chain reaction was used to detect genes coding for carbapenemases. A generalized linear mixed model was used to identify risk factors for mortality.

FINDINGS

In total, 290 individuals with CPO were identified. The overall incidence increased over time (P<0.001) from 0.02 to 1.38 per 100,000 population between 2003 and 2017. A total of 243 distinct CPO isolates were obtained from 269 isolations in 214 individuals with available metadata. The majority of the isolates were Enterobacterales (206/243, 84.8%), and Klebsiella pneumoniae (65/206, 31.6%) and Enterobacter cloacae (52/206, 25.2%) were the most common species. VIM (75/243, 30.9%) and NDM (56/243, 23.0%) were the most common carbapenemases. The crude 30-day mortality rate was 11.8% (25/211), while the case fatality rate was 5.7% (12/211). Age >60 years [adjusted odds ratio (aOR) 3.36, 95% confidence interval (CI) 1.06-10.63; P=0.033], presence of non-fermenters (aOR 4.88, 95% CI 1.64-14.47; P=0.005), and systemic infection or organ failure (aOR 4.21, 95% CI 1.38-12.81; P=0.032) were independently associated with 30-day mortality.

CONCLUSION

The incidence of CPO in Scotland is low but increasing. Awareness is required that inpatients aged >60 years, patients with systemic infection or organ failure, and patients presenting with non-fermenters are at higher risk of death from CPO.

Comparison of transarterial bland and chemoembolization for neuroendocrine tumours: a systematic review and meta-analysis

Background

Treatment of hepatic metastases from neuroendocrine tumours improves survival and symptom relief. Hepatic arterial embolotherapy techniques include transarterial chemoembolization (tace) and bland embolization (tae). The relative efficacy of the techniques is controversial. The purpose of the present study was to use a meta-analysis and systematic review to compare tace with tae in the treatment of hepatic metastases.

Methods

A literature search identified studies comparing tace and tae for treatment of hepatic metastases. Outcomes of interest included overall survival (os), progression-free survival (pfs), radiographic response, complications, and symptom control. The hazard ratios (hrs) and odds ratios (ors) were estimated and pooled.

Results

Eight studies and 504 patients were included. No statistically significant differences between tace and tae were observed for os at 1, 2, and 5 years or for hrs [1-year or: 0.72; 95% confidence interval (ci): 0.27 to 1.94; p < 0.52; 2-year or: 0.69; 95% ci: 0.43 to 1.11; p < 0.12; 5-year or: 0.91; 95% ci: 0.37 to 2.24; p < 0.85; hr: 0.96; 95% ci: 0.73 to 1.24; p < 0.74]. No statistically significant differences between tace and tae were observed for pfs at 1, 2, and 5 years or for hrs (1-year or: 0.71; 95% ci: 0.38 to 1.55; p < 0.30; 2-year or: 0.83; 95% ci: 0.33 to 2.06; p < 0.69; 5-year or: 0. 91; 95% ci: 0.37 to 2.24; p < 0.85; hr: 0.99-1.74; 95% ci: 0.74 to 1.73; p < 0.97). Both techniques are safe and effective for symptom control.

Conclusions

No statistically significant differences between tace and tae were observed for os and pfs.

OP0188 INTEGRATED SAFETY SUMMARY OF THE NOVEL, INTRA-ARTICULAR AGENT LORECIVIVINT (SM04690), A CLK/DYRK1A INHIBITOR THAT MODULATES THE WNT PATHWAY, IN SUBJECTS WITH KNEE OSTEOARTHRITIS

Background:

Concerns over the safety of available osteoarthritis (OA) treatments have led to revision of treatment guidelines and highlight the need for new therapies. Lorecivivint (LOR; SM04690) is an intra-articular (IA), small-molecule CLK/DYRK1A inhibitor that modulates the Wnt pathway and is in development as a potential disease-modifying treatment for knee OA.1,2

Objectives:

To evaluate pooled early-phase LOR clinical data for safety, including bone health-related adverse events (AEs).

Methods:

Safety data were pooled from 3 randomized controlled trials (one Phase 1, two Phase 2) evaluating 4 doses (0.03 mg, 0.07 mg, 0.15 mg, 0.23 mg) of a single IA injection of LOR in subjects with moderately to severely symptomatic knee OA. Two trials (NCT02095548;NCT03122860) evaluated subjects for 24 weeks and one trial (NCT02536833) for 52 weeks. AEs, serious AEs (SAEs), and bone health AEs were categorized by Medical Dictionary for Regulatory Activities (MedDRA) classification. Incidences of AEs and SAEs were compared between the combined LOR-treated group (subjects who received any dose of LOR) and a control group (subjects not treated with LOR).

Results:

This analysis includes 848 LOR-treated and 360 control subjects. The incidence of AEs was similar in LOR-treated (350/848 [41.3%]) and control subjects (138/360 [38.3%]). Incidence of SAEs was 20/848 (2.4%) in LOR-treated and 4/360 (1.1%) in control subjects. The most commonly reported AE in LOR-treated subjects was arthralgia (treated 7.6%, control 7.2%) and was the only AE reported at >5% in either group (Fig. 1). Target-knee arthralgia was the most common joint-specific AE (treated 6.5%, control 5.3%) (Fig. 2). No AEs in other joints exceeded an incidence of 2% in either group. In all categories, individual AEs were reported at similar rates between groups and no SAEs were deemed related to LOR by investigators.

Figure 1.

Adverse event summary for events occurring in at least 1% of the treated population (N=1208).

Figure 2.

Joint-specific adverse event summary, subcategorized by affected joint, for events occurring in at least 1% of the treated population (N=1208).

There were 16 bone health-related AEs in 9/848 (1.1%) LOR-treated and 3/360 (0.8%) control subjects. Of the bone health AEs, 2 were osteopenia/osteoporosis in 2 LOR-treated postmenopausal women and 14 were fractures in 10 subjects (7 LOR-treated, 3 control). All fractures (3 patellar [1 target knee, 2 non-target knee], 3 vertebral, 2 foot, 2 wrist, 2 rib, 1 fibula, 1 hand) were adjudicated and determined to be caused by trauma; all healed uneventfully within the expected time frame.

Conclusion:

In exposure to date of 848 subjects, IA LOR for the treatment of knee OA appeared to be safe and well tolerated. These data support the continued evaluation of LOR as a potential treatment for knee OA.

References:

[1]Deshmukh V, et al.Osteoarthritis Cartilage. 2017.

[2]Deshmukh V, et al.Osteoarthritis Cartilage. 2019.

Disclosure of Interests:

Ismail Simsek Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Christopher Swearingen Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Sarah Kennedy Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Jeyanesh Tambiah Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Cristina Damatarca Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Grant/research support from: Bristol-Myers Squibb, Celgene, and Genentech, Consultant of: Celgene and Sanofi, Employee of: Samumed, LLC, Nancy Lane Consultant of: Samumed, LLC, Marc Hochberg: None declared

FRI0380 ITEMS DRIVING WOMAC PAIN SUBSCORE CHANGES DUE TO LORECIVIVINT, A POTENTIAL DISEASE-MODIFYING TREATMENT FOR KNEE OSTEOARTHRITIS: A POST HOC ANALYSIS OF PHASE 2B TRIAL DATA

Background:

Knee osteoarthritis (OA) is a disease characterized by pain, loss of function, and structural deformities, leading to a heterogeneous disease state that can confound patient-reported outcomes (PROs). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain subscore addresses this reporting variability by capturing multiple pain items related to ‘active’ and ‘static’ subject states. We hypothesize that measurement of these ‘active’ versus ‘static’ pain items may demonstrate differential effect sizes when assessing treatment benefit. Lorecivivint (LOR; SM04690), a small-molecule, intra-articular CLK/DYRK1A inhibitor that modulates the Wnt pathway, is currently in development as a potential disease-modifying treatment for knee OA.1,2

Objectives:

To test the hypothesis, a post hoc analysis of Pain NRS, the WOMAC Pain subscore, and individual WOMAC PROs (items A1–A5) from a Phase 2b LOR trial was performed to examine effect size (ES) changes.

Methods:

The original 24-week Phase 2b trial has been previously reported. In this study, pain was assessed using the weekly average of daily Pain NRS and WOMAC Pain subscore. In the post hoc analysis, items A1–A5 (pain walking on a flat surface? [A1], going up/downstairs? [A2], at night in bed? [A3], sitting or lying down? [A4], and while standing? [A5]) were individually analyzed for subjects treated with 0.07 mg LOR and compared with the primary study outcomes of mean Pain NRS and summed mean WOMAC Pain subscore at Week 12. Baseline-adjusted analysis of covariance for WOMAC A1–A5 scores was conducted on LOR-treated subjects compared with placebo (PBO) in 1) the Full Analysis Set (FAS) of all dosed subjects and 2) a target population of subjects with fixed baseline joint space width (JSW) [2–4] mm without widespread pain (Widespread Pain Index [WPI] ≤4, Symptom Severity Score Question 2≤2).

Results:

In this analysis, 231 subjects (KL grade 3 63.2%) were included. The primary study analysis demonstrated efficacy of LOR compared with PBO for Pain NRS and WOMAC Pain, with respective effect sizes of 0.450 and 0.293 (Figure). In the target population, Pain NRS and WOMAC A effect sizes increased (0.637 and 0.410, respectively). Each WOMAC A item showed less of an effect size than Pain NRS at Week 12. Treatment with 0.07 mg LOR compared with PBO showed significant improvements in effect sizes of WOMAC A1 (FAS: ES=0.315,P=0.028; target population: ES=0.421,P=0.035) and A2 (FAS: ES=0.392,P=0.006; target population: ES=0.510,P=0.011). A3–A5 did not show statistical improvement for LOR compared with PBO.

Figure.

Effect sizes for 0.07 mg LOR compared with PBO for the FAS and target population at Week 12.

Conclusion:

In the post hoc analysis, Pain NRS exhibited the greatest effect size of tested PROs after treatment with 0.07 mg LOR compared with PBO. These effect sizes were enhanced in the target population with fixed baseline JSW and without widespread pain for all scores relative to the FAS. WOMAC ‘active’ questions demonstrated greater effect sizes with LOR treatment than ‘static’ questions and the full WOMAC Pain domain, providing support for the hypothesized dimensional constructs in knee OA pain assessment.

References:

[1]Deshmukh V, et al.Osteoarthritis Cartilage. 2017.

[2]Deshmukh V, et al.Osteoarthritis Cartilage. 2019.

Disclosure of Interests:

Sarah Kennedy Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Christopher Swearingen Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Ismail Simsek Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Jeyanesh Tambiah Shareholder of: Samumed, LLC, Employee of: Samumed, LLC

FRI0430 THE NOVEL, INTRA-ARTICULAR CLK/DYRK1A INHIBITOR LORECIVIVINT (LOR; SM04690), WHICH MODULATES THE WNT PATHWAY, IMPROVED RESPONDER OUTCOMES IN SUBJECTS WITH KNEE OSTEOARTHRITIS: A POST HOC ANALYSIS FROM A PHASE 2B TRIAL

Background:

Lorecivivint (LOR; SM04690) is a small-molecule, intra-articular (IA) CLK/DYRK1A inhibitor that modulates the Wnt pathway1and has demonstrated some beneficial effects on patient-reported outcomes (PROs) relative to placebo (PBO) in two Phase 2 knee OA trials. With subjective measures such as PROs, meaningful benefits may be better characterized by representation as discrete threshold responses rather than by changes in mean point estimates.

Objectives:

To conduct a post hoc analysis of subjects in a 24-week Phase 2b study by measuring the proportions of subjects treated with LOR and placebo (PBO) who achieved 30%, 50%, or 70% threshold responses of improvement over baseline in Pain Numeric Rating Scale (NRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Function, and Patient Global Assessment (PtGA) at Week 12. Results from the Phase 3-selected dose of 0.07 mg LOR are presented here.

Methods:

Subjects had ACR-defined knee OA, Kellgren-Lawrence (KL) grades 2–3, and Pain NRS scores ≥4 and ≤8 in the target knee and <4 in the contralateral knee. A single 2mL IA injection of 0.03 mg, 0.07 mg, 0.15 mg, or 0.23 mg LOR, or vehicle PBO was given in the target knee at baseline. The proportion of subjects meeting 30%, 50%, or 70% threshold responses over baseline in the weekly average of daily Pain NRS [0–10], WOMAC Pain [0–100], WOMAC Function [0–100], and PtGA [0–100] at Week 12 was determined. The odds ratios (OR [95% CI]) of achieving each threshold response level were calculated and compared between LOR and PBO.

Results:

In total, 635 subjects (91.4%) completed the study (mean age 59.0±8.5 years, BMI 29.0±4.0 kg/m2, female 58.4%, KL grade 3 57.3%). At Week 12, treatment with 0.07 mg LOR significantly (P<0.05) increased the odds of a 30% threshold response in Pain NRS (OR 2.47 [1.45, 4.19]) and WOMAC Function (OR 1.86 [1.10, 3.12]) and a 50% threshold response in WOMAC Pain (OR 1.79 [1.06, 3.03]) and PtGA (OR 2.28 [1.25, 4.16]). Numerically, more (not statistically significant) subjects achieved a 70% threshold response in all PROs. All improvements were maintained through Week 24.

Conclusion:

In this post hoc analysis, LOR-treated subjects reported greater improvements in PRO threshold responses versus PBO from Week 12 through Week 24. LOR demonstrated significantly higher odds of achieving and maintaining improvements in PROs at 30% and 50% thresholds. Phase 3 studies of 0.07 mg LOR are ongoing.

References:

[1]Deshmukh V, et al.Osteoarthr Cartil. 2019.

Disclosure of Interests:

Yusuf Yazici Shareholder of: Samumed, LLC, Grant/research support from: Bristol-Myers Squibb, Celgene, and Genentech, Consultant of: Celgene and Sanofi, Employee of: Samumed, LLC, Sarah Kennedy Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Christopher Swearingen Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Jeyanesh Tambiah Shareholder of: Samumed, LLC, Employee of: Samumed, LLC

Modulation of the Wnt pathway through inhibition of CLK2 and DYRK1A by lorecivivint as a novel, potentially disease-modifying approach for knee osteoarthritis treatment

OBJECTIVES

Wnt pathway upregulation contributes to knee osteoarthritis (OA) through osteoblast differentiation, increased catabolic enzymes, and inflammation. The small-molecule Wnt pathway inhibitor, lorecivivint (SM04690), which previously demonstrated chondrogenesis and cartilage protection in an animal OA model, was evaluated to elucidate its mechanism of action.

DESIGN

Biochemical assays measured kinase activity. Western blots measured protein phosphorylation in human mesenchymal stem cells (hMSCs), chondrocytes, and synovial fibroblasts. siRNA knockdown effects in hMSCs and BEAS-2B cells on Wnt pathway, chondrogenic genes, and LPS-induced inflammatory cytokines was measured by qPCR. In vivo anti-inflammation, pain, and function were evaluated following single intra-articular (IA) lorecivivint or vehicle injection in the monosodium iodoacetate (MIA)-induced rat OA model.

RESULTS

Lorecivivint inhibited intranuclear kinases CDC-like kinase 2 (CLK2) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Lorecivivint inhibited CLK2-mediated phosphorylation of serine/arginine-rich (SR) splicing factors and DYRK1A-mediated phosphorylation of SIRT1 and FOXO1. siRNA knockdowns identified a role for CLK2 and DYRK1A in Wnt pathway modulation without affecting β-catenin with CLK2 inhibition inducing early chondrogenesis and DYRK1A inhibition enhancing mature chondrocyte function. NF-κB and STAT3 inhibition by lorecivivint reduced inflammation. DYRK1A knockdown was sufficient for anti-inflammatory effects, while combined DYRK1A/CLK2 knockdown enhanced this effect. In the MIA model, lorecivivint inhibited production of inflammatory cytokines and cartilage degradative enzymes, resulting in increased joint cartilage, decreased pain, and improved weight-bearing function.

CONCLUSIONS

Lorecivivint inhibition of CLK2 and DYRK1A suggested a novel mechanism for Wnt pathway inhibition, enhancing chondrogenesis, chondrocyte function, and anti-inflammation. Lorecivivint shows potential to modify structure and improve symptoms of knee OA.

Women's and healthcare providers' perceptions of long-term complications associated with hypertension and diabetes in pregnancy: a qualitative study

Objectives

A diagnosis of hypertensive disorders during pregnancy (HDPs) or gestational diabetes mellitus (GDM) is highly predictive of women at increased risk of developing chronic hypertension, Type 2 diabetes, and cardiovascular disease. This study investigates perceptions of women and healthcare providers in rural India regarding these long‐term risks.

Design

Qualitative study using modified grounded theory.

Setting

Two states in rural India: Haryana and Andhra Pradesh.

Population

Pregnant and postpartum women, community health workers (CHWs), primary care physicians, obstetricians, laboratory technicians, and healthcare officials.

Methods

In‐depth interviews and focus group discussions explored: (1) priorities for high‐risk pregnant women; (2) detection and management of HDPs and GDM; (3) postpartum management, and (4) knowledge of long‐term sequelae of high‐risk conditions. A thematic analysis was undertaken.

Results

Seven focus group discussions and 11 in‐depth interviews (n = 71 participants) were performed. The key priority area for high‐risk pregnant women was anaemia. Blood pressure measurement was routinely embedded in antenatal care; however, postpartum follow up and knowledge of the long‐term complications were limited. GDM was not considered a common problem, although significant variations and challenges to GDM screening were identified. Knowledge of the long‐term sequelae of GDM with regard to an increased risk of Type 2 diabetes and cardiovascular disease among doctors was minimal.

Conclusions

There is a need for improved education, standardisation of testing and postpartum follow up of HDPs and GDM in rural Indian settings.

Funding

SN is supported by an MRC Clinical Research Training Fellowship (MR/R017182/1). The George Institute for Global Health Global Women's Health programme provided financial support for the research assistant and fieldwork costs in India.

Tweetable abstract

Improved education and postpartum care of women with hypertension and diabetes in pregnancy in rural India are needed to prevent long‐term risks.

Improved education and postpartum care of women with hypertension and diabetes in pregnancy in rural India are needed to prevent long‐term risks.

Short Periods of Hypoxia Upregulate Sphingosine Kinase 1 and Increase Vasodilation of Arteries to Sphingosine 1-Phosphate (S1P) via S1P3

Sphingosine kinase [(SK), isoforms SK1 and SK2] catalyzes the formation of the bioactive lipid, sphingosine 1-phosphate (S1P). This can be exported from cells and bind to S1P receptors to modulate vascular function. We investigated the effect of short-term hypoxia on SK1 expression and the response of arteries to S1P. SK1 expression in rat aortic and coronary artery endothelial cells was studied using immunofluorescence and confocal microscopy. Responses of rat aortic rings were studied using wire myography and reversible hypoxia induced by bubbling myography chambers with 95% N₂:5% CO₂ Inhibitors were added 30 minutes before induction of hypoxia. S1P induced endothelium-dependent vasodilation via activation of S1P₃ receptors and generation of nitric oxide. Hypoxia significantly increased relaxation to S1P and this was attenuated by (2R)-1-[[(4-[[3-methyl-5-[(phenylsulfonyl)methyl] phenoxy]methyl]phenyl]methyl]-2-pyrrolidinemethanol [(PF-543), SK1 inhibitor] but not (R)-FTY720 methyl ether [(ROMe), SK2 inhibitor]. Hypoxia also increased vessel contractility to the thromboxane mimetic, 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin F2α, which was further increased by PF-543 and ROMe. Hypoxia upregulated SK1 expression in aortic and coronary artery endothelial cells and this was blocked by PF-543 and 2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole [(SKi), SK1/2 inhibitor]. The effects of PF-543 and SKi were associated with increased proteasomal/lysosomal degradation of SK1. A short period of hypoxia increases the expression of SK1, which may generate S1P to oppose vessel contraction. Under hypoxic conditions, upregulation of SK1 is likely to lead to increased export of S1P from the cell and vasodilation via activation of endothelial S1P₃ receptors. These data have significance for perfusion of tissue during episodes of ischemia.

Predisposing and protective factors influencing suicide ideation, attempt, and death in patients accessing substance use treatment: a systematic review and meta-analysis protocol

BACKGROUND

The lifetime risk of suicide in patients with substance use disorder is five to ten times the risk in the general population. Critically, up to 19% of patients continue to think about and attempt suicide even after accessing treatment. Therefore, suicidality represents a significant clinical concern in patients struggling with substance use that warrants careful investigation of the factors involved. While most previous research has relied on limited cross-sectional designs, a growing number of prospective studies are improving our understanding of the factors involved. However, a systematic study of these factors has not yet been conducted.

METHODS

The primary objective of this review and possible meta-analysis will be to identify key risk and protective factors for suicide ideation, attempt, and death in patients accessing substance use treatment, guided by current models of suicide. Secondary and tertiary objectives will be to obtain pooled effect sizes for the factors identified and to disaggregate factors for suicidality before and after treatment, and for suicidal thought versus action. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we will conduct an electronic search of the literature using the databases Embase, Medline, PsycINFO, and Web of Science. Two authors will independently screen studies based on pre-specified inclusion and exclusion criteria, extract relevant data, and assess study quality. Observational and randomized-controlled studies will be included, whereas case-studies and reviews will be excluded. We will extract data on risk and protective factors associated with suicide ideation, attempt (odds or risk ratios), and death (hazard ratio). Given sufficient data (> 5 studies), we will calculate pooled effects using comprehensive meta-analysis.

DISCUSSION

This systematic review will contribute to our knowledge of risk and protective factors for suicidality in patients before and after treatment. Understanding these factors will help define areas of research for further investigation to ultimately inform risk assessment and prevention strategies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (reference number: CRD42018076260).

Combining mathematical modelling with in vitro experiments to predict in vivo drug-eluting stent performance

In this study, we developed a predictive model of in vivo stent based drug release and distribution that is capable of providing useful insights into performance. In a combined mathematical modelling and experimental approach, we created two novel sirolimus-eluting stent coatings with quite distinct doses and release kinetics. Using readily measurable in vitro data, we then generated parameterised mathematical models of drug release. These were then used to simulate in vivo drug uptake and retention. Finally, we validated our model predictions against data on drug kinetics and efficacy obtained in a small in vivo evaluation. In agreement with the in vivo experimental results, our mathematical model predicted consistently higher sirolimus content in tissue for the higher dose stents compared with the lower dose stents. High dose stents resulted in statistically significant improvements in three key efficacy measures, providing further evidence of a basic relationship between dose and efficacy within DES. However, our mathematical modelling suggests a more complex relationship is at play, with efficacy being dependent not only on delivering an initial dose of drug sufficient to achieve receptor saturation, but also on the consequent drug release rate being tuned to ensure prolonged saturation. In summary, we have demonstrated that our combined in vitro experimental and mathematical modelling framework may be used to predict in vivo DES performance, opening up the possibility of an in silico approach to optimising the drug release profile and ultimately the effectiveness of the device.

Toxic epidermal necrolysis after acute burn injury

Toxic epidermal necrolysis is a rare, potentially fatal disorder that involves large areas of skin desquamation. Patients with toxic epidermal necrolysis are frequently referred to burn centres for expert wound management and early comprehensive critical care as this has been shown to improve patient outcome and mortality. The authors describe the first report of medication-induced toxic epidermal necrolysis occurring in a patient during acute burn management in a tertiary burn care facility. The patient sustained a 17% total body surface area flame burn to her face, chest, bilateral upper limbs and bilateral lower limbs while escaping from a wildfire. She required extensive debridement and allografting to manage burn injured areas and additional areas of epidermal loss from subsequent toxic epidermal necrolysis, amounting to a total body surface area of 90%. Definitive burn wound closure was achieved using autologous split-thickness skin grafting once donor sites healed and became suitable for harvest 3 weeks after the onset of toxic epidermal necrolysis. Grafts achieved complete take and the patient was discharged home following rehabilitation..

Requirement for sphingosine kinase 1 in mediating phase 1 of the hypotensive response to anandamide in the anaesthetised mouse

In the isolated rat carotid artery, the endocannabinoid anandamide induces endothelium-dependent relaxation via activation of the enzyme sphingosine kinase (SK). This generates sphingosine-1-phosphate (S1P) which can be released from the cell and activates S1P receptors on the endothelium. In anaesthetised mice, anandamide has a well-characterised triphasic effect on blood pressure but the contribution of SK and S1P receptors in mediating changes in blood pressure has never been studied. Therefore, we assessed this in the current study.

The peak hypotensive response to 1 and 10 mg/kg anandamide was measured in control C57BL/6 mice and in mice pretreated with selective inhibitors of SK1 (BML-258, also known as SK1-I) or SK2 ((R)-FTY720 methylether (ROMe), a dual SK1/2 inhibitor (SKi) or an S1P₁ receptor antagonist (W146). Vasodilator responses to S1P were also studied in isolated mouse aortic rings.

The hypotensive response to anandamide was significantly attenuated by BML-258 but not by ROMe. Antagonising S1P₁ receptors with W146 completely blocked the fall in systolic but not diastolic blood pressure in response to anandamide. S1P induced vasodilation in denuded aortic rings was blocked by W146 but caused no vasodilation in endothelium-intact rings.

This study provides evidence that the SK1/S1P regulatory-axis is necessary for the rapid hypotension induced by anandamide. Generation of S1P in response to anandamide likely activates S1P₁ to reduce total peripheral resistance and lower mean arterial pressure. These findings have important implications in our understanding of the hypotensive and cardiovascular actions of cannabinoids.

Molecular mechanisms regulating perivascular adipose tissue - potential pharmacological targets?

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Canagliflozin inhibits interleukin-1β-stimulated cytokine and chemokine secretion in vascular endothelial cells by AMP-activated protein kinase-dependent and -independent mechanisms

Recent clinical trials of the hypoglycaemic sodium-glucose co-transporter-2 (SGLT2) inhibitors, which inhibit renal glucose reabsorption, have reported beneficial cardiovascular outcomes. Whether SGLT2 inhibitors directly affect cardiovascular tissues, however, remains unclear. We have previously reported that the SGLT2 inhibitor canagliflozin activates AMP-activated protein kinase (AMPK) in immortalised cell lines and murine hepatocytes. As AMPK has anti-inflammatory actions in vascular cells, we examined whether SGLT2 inhibitors attenuated inflammatory signalling in cultured human endothelial cells. Incubation with clinically-relevant concentrations of canagliflozin, but not empagliflozin or dapagliflozin activated AMPK and inhibited IL-1β-stimulated adhesion of pro-monocytic U937 cells and secretion of IL-6 and monocyte chemoattractant protein-1 (MCP-1). Inhibition of MCP-1 secretion was attenuated by expression of dominant-negative AMPK and was mimicked by the direct AMPK activator, A769662. Stimulation of cells with either canagliflozin or A769662 had no effect on IL-1β-stimulated cell surface levels of adhesion molecules or nuclear factor-κB signalling. Despite these identical effects of canagliflozin and A769662, IL-1β-stimulated IL-6/MCP-1 mRNA was inhibited by canagliflozin, but not A769662, whereas IL-1β-stimulated c-jun N-terminal kinase phosphorylation was inhibited by A769662, but not canagliflozin. These data indicate that clinically-relevant canagliflozin concentrations directly inhibit endothelial pro-inflammatory chemokine/cytokine secretion by AMPK-dependent and -independent mechanisms without affecting early IL-1β signalling.

Gait evaluation in hip osteoarthritic and normal dogs using a serial force plate system

The effect of canine hip osteoarthritis (OA) on vertical force distribution was studied using a serial force platform system. This system allows simultaneous measurement of vertical and horizontal force impulses from each limb of a trotting dog. Using these measurements and novel analysis techniques a complete and precise analysis of load distribution was performed. Load distribution was compared between a group of normal dogs and a group of dogs with radiographic evidence of hip OA. Results of this study indicate that trotting dogs with hip OA redistribute vertical force primarily by shifting force between trotting pairs (side-to-side compensation) rather than within trotting pairs (hind-to-fore compensation).

High Fat Diet Attenuates the Anticontractile Activity of Aortic PVAT via a Mechanism Involving AMPK and Reduced Adiponectin Secretion

Background and aim: Perivascular adipose tissue (PVAT) positively regulates vascular function through production of factors such as adiponectin but this effect is attenuated in obesity. The enzyme AMP-activated protein kinase (AMPK) is present in PVAT and is implicated in mediating the vascular effects of adiponectin. In this study, we investigated the effect of an obesogenic high fat diet (HFD) on aortic PVAT and whether any changes involved AMPK.

Methods: Wild type Sv129 (WT) and AMPKα1 knockout (KO) mice aged 8 weeks were fed normal diet (ND) or HFD (42% kcal fat) for 12 weeks. Adiponectin production by PVAT was assessed by ELISA and AMPK expression studied using immunoblotting. Macrophages in PVAT were identified using immunohistochemistry and markers of M1 and M2 macrophage subtypes evaluated using real time-qPCR. Vascular responses were measured in endothelium-denuded aortic rings with or without attached PVAT. Carotid wire injury was performed and PVAT inflammation studied 7 days later.

Key results: Aortic PVAT from KO and WT mice was morphologically indistinct but KO PVAT had more infiltrating macrophages. HFD caused an increased infiltration of macrophages in WT mice with increased expression of the M1 macrophage markers Nos2 and Il1b and the M2 marker Chil3. In WT mice, HFD reduced the anticontractile effect of PVAT as well as reducing adiponectin secretion and AMPK phosphorylation. PVAT from KO mice on ND had significantly reduced adiponectin secretion and no anticontractile effect and feeding HFD did not alter this. Wire injury induced macrophage infiltration of PVAT but did not cause further infiltration in KO mice.

Conclusions: High-fat diet causes an inflammatory infiltrate, reduced AMPK phosphorylation and attenuates the anticontractile effect of murine aortic PVAT. Mice lacking AMPKα1 phenocopy many of the changes in wild-type aortic PVAT after HFD, suggesting that AMPK may protect the vessel against deleterious changes in response to HFD.

What is Comprehensive Geriatric Assessment (CGA)? An umbrella review

Background

Comprehensive Geriatric Assessment (CGA) is now the accepted gold standard for caring for frail older people in hospital. However, there is uncertainty about identifying and targeting suitable recipients and which patients benefit the most.

Objectives

our objectives were to describe the key elements, principal measures of outcome and the characteristics of the main beneficiaries of inpatient CGA.

Methods

we used the Joanna Briggs Institute umbrella review method. We searched for systematic reviews and meta-analyses describing CGA services for hospital inpatients in the Cochrane Database of Systematic Reviews, Database of Reviews of Effectiveness (DARE), MEDLINE and EMBASE and a range of other sources.

Results

we screened 1,010 titles and evaluated 419 abstracts for eligibility, 143 full articles for relevance and included 24 in a final quality and relevance check. Thirteen reviews, reported in 15 papers, were selected for review. The most widely used definition of CGA was: 'a multidimensional, multidisciplinary process which identifies medical, social and functional needs, and the development of an integrated/co-ordinated care plan to meet those needs'. Key clinical outcomes included mortality, activities of daily living and dependency. The main beneficiaries were people ≥55 years in receipt of acute care. Frailty in CGA recipients and patient related outcomes were not usually reported.

Conclusions

we confirm a widely used definition of CGA. Key outcomes are death, disability and institutionalisation. The main beneficiaries in hospital are older people with acute illness. The presence of frailty has not been widely examined as a determinant of CGA outcome.