Grand Challenges at the Interface of Engineering and Medicine

Over the past two decades Biomedical Engineering has emerged as a major discipline that bridges societal needs of human health care with the development of novel technologies. Every medical institution is now equipped at varying degrees of sophistication with the ability to monitor human health in both non-invasive and invasive modes. The multiple scales at which human physiology can be interrogated provide a profound perspective on health and disease. We are at the nexus of creating "avatars" (herein defined as an extension of "digital twins") of human patho/physiology to serve as paradigms for interrogation and potential intervention. Motivated by the emergence of these new capabilities, the IEEE Engineering in Medicine and Biology Society, the Departments of Biomedical Engineering at Johns Hopkins University and Bioengineering at University of California at San Diego sponsored an interdisciplinary workshop to define the grand challenges that face biomedical engineering and the mechanisms to address these challenges. The Workshop identified five grand challenges with cross-cutting themes and provided a roadmap for new technologies, identified new training needs, and defined the types of interdisciplinary teams needed for addressing these challenges. The themes presented in this paper include: 1) accumedicine through creation of avatars of cells, tissues, organs and whole human; 2) development of smart and responsive devices for human function augmentation; 3) exocortical technologies to understand brain function and treat neuropathologies; 4) the development of approaches to harness the human immune system for health and wellness; and 5) new strategies to engineer genomes and cells.

"There should be one spot that you can go:" BRCA mutation carriers' perspectives on cancer risk management and a hereditary cancer registry

Individuals who carry BRCA1 or BRCA2 pathogenic variants are recommended to have extensive cancer prevention screening and risk-reducing surgeries. Uptake of these recommendations is variable, and there remains room for improvement in the risk management of BRCA carriers. This paper explores female BRCA carriers' experiences with the current model of care and their perspectives on (and interest in) an inherited cancer registry. Findings can inform the development of a dedicated high-risk screening and management program for these patients. Quantitative and qualitative data were gathered through a provincial descriptive survey and semi-structured qualitative interviews to assess BRCA carriers' opinions toward risk management services in the province of Newfoundland and Labrador (NL), Canada. Survey (n = 69) and interview data (n = 15) revealed continuity and coordination challenges with the current system of care of high-risk individuals. Respondents suggested an inherited cancer registry would help identify high-risk individuals and provide a centralized system of risk management for identified carriers. Respondents identified concerns about the privacy of their registry data, including who could access it. Findings suggest BRCA carriers see great value in an inherited cancer registry. Specifically, participants noted it could provide a centralized system to help improve the coordination of burdensome, life-long risk management. Important patient concerns about protecting their privacy and their health data confidentiality must be addressed in patient and public information and informed consent documents about a registry.

A latent class analysis of mental disorders, substance use, and aggressive antisocial behavior among Swedish forensic psychiatric patients

BACKGROUND

Patients in the forensic mental health services (FMHS) with a mental disorder, a co-occurring substance use disorder (SUD), and high risk of aggressive antisocial behavior (AAB) are sometimes referred to as the 'triply troubled'. They suffer poor treatment outcomes, high rates of criminal recidivism, and increased risk of drug related mortality. To improve treatment for this heterogeneous patient group, more insight is needed concerning their co-occurring mental disorders, types of substances used, and the consequent risk of AAB.

METHODS

A three-step latent class analysis (LCA) was used to identify clinically relevant subgroups in a sample of patients (n = 98) from a high-security FMHS clinic in Sweden based on patterns in their history of mental disorders, SUD, types of substances used, and AAB.

RESULTS

A four-class model best fit our data: class 1 (42%) had a high probability of SUD, psychosis, and having used all substances; class 2 (26%) had a high probability of psychosis and cannabis use; class 3 (22%) had a high probability of autism and no substance use; and class 4 (10%) had a high probability of personality disorders and having used all substances. Both polysubstance classes (1 and 4) had a significantly more extensive history of AAB compared to classes 2 and 3. Class 3 and class 4 had extensive histories of self-directed aggression.

CONCLUSIONS

The present study helps disentangle the heterogeneity of the 'triply troubled' patient group in FMHS. The results provide an illustration of a more person-oriented perspective on patient comorbidity and types of substances used which could benefit clinical assessment, treatment planning, and risk-management among patients in forensic psychiatric care.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

The Current Proposed Total Hip Arthroplasty Surgical Planning Guidelines Based on Classification of Spine Stiffness May be Flawed Due to Incorrect Assumptions

BACKGROUND

The available classifications and preoperative planning tools for total hip arthroplasty assume that: 1) there is no variation in the sagittal pelvic tilt (SPT) if the radiographs are repeated, and 2) there is no significant change in the postoperative SPT postoperatively. We hypothesized that there would be significant differences in postoperative SPT tilt as measured by the sacral slope, thus rendering the current classifications and tools flawed.

METHODS

This study was a multicenter, retrospective analysis of preoperative and postoperative (1.5-6 months) full-body imaging of 237 primary total hip arthroplasty (standing and sitting positions). Patients were categorized as 1) stiff spine (standing sacral slope sitting sacral slope < 10°) and 2) normal spine (standing sacral slope-sitting sacral slope ≥ 10°). Results were compared using the paired t-test. The posthoc power analysis showed a power of 0.99.

RESULTS

The difference in mean standing and sitting sacral slope between the preoperative and postoperative measurements was 1°. However, in standing position, this difference was more than 10° in 14.4% of patients. In the sitting position, this difference was more than 10° in 34.2% of patients and more than 20° in 9.8% of patients. Postoperatively, 32.5% of patients switched groups based on the classification, which rendered the preoperative planning suggested by the current classifications flawed.

CONCLUSION

Current preoperative planning and classifications are based on a single acquisition of preoperative radiographs without the incorporation of possible postoperative changes in SPT. Validated classifications and planning tools should incorporate repeated measurements to determine the mean and variance in SPT and consider the significant postoperative changes in SPT.

The reality of advanced airway management during out of hospital cardiac arrest; why did paramedics deviate from their allocated airway management strategy during the AIRWAYS-2 randomised trial?

Background

AIRWAYS-2 was a large multi-centre cluster randomised controlled trial investigating the effect on functional outcome of a supraglottic airway device (i-gel) versus tracheal intubation (TI) as the initial advanced airway during out-of-hospital cardiac arrest. We aimed to understand why paramedics deviated from their allocated airway management algorithm during AIRWAYS-2.

Methods

This study employed a pragmatic sequential explanatory design utilising retrospective study data collected during the AIRWAYS-2 trial. Airway algorithm deviation data were analysed to categorise and quantify the reasons why paramedics did not follow their allocated strategy of airway management during AIRWAYS-2. Recorded free text entries provided additional context to the paramedic decision-making related to each category identified.

Results

In 680 (11.7%) of 5800 patients the study paramedic did not follow their allocated airway management algorithm. There was a higher percentage of deviations in the TI group (399/2707; 14.7%) compared to the i-gel group (281/3088; 9.1%). The predominant reason for a paramedic not following their allocated airway management strategy was airway obstruction, occurring more commonly in the i-gel group (109/281; 38.7%) versus (50/399; 12.5%) in the TI group.

Conclusion

There was a higher proportion of deviations from the allocated airway management algorithm in the TI group (399; 14.7%) compared to the i-gel group (281; 9.1%). The most frequent reason for deviating from the allocated airway management algorithm in AIRWAYS-2 was obstruction of the patient's airway by fluid. This occurred in both groups of the AIRWAYS-2 trial, but was more frequent in the i-gel group.

Implementing clinical guidelines for co-occurring substance use and major mental disorders in Swedish forensic psychiatry: An exploratory, qualitative interview study with mental health care staff

INTRODUCTION

Patients with substance use disorders (SUD) and co-occurring mental disorders (COD) within forensic psychiatric care often suffer poor treatment outcomes and high rates of criminal recidivism, substance use, and psychiatric problems. This study aimed to describe the conditions for, and mental health care staff's experiences with, implementing integrated SUD-focused clinical guidelines, including assessment and treatment for patients with COD at a high-security forensic mental health services (FMHS) facility in Sweden.

METHODS

Study staff conducted nineteen semi-structured interviews with health care staff experienced in administering the new SUD assessment and treatment. The study conducted a thematic analysis to describe the health care staff's experiences with these guidelines and suggestions for improvement.

RESULTS

Most participants reported appreciation for the implementation of clinical guidelines with an SUD focus, an area they considered to have previously been neglected, but also noted the need for more practical guidance in the administration of the assessments. Participants reported the dual roles of caregiver and warden as difficult to reconcile and a similar, hindering division was also present in the health care staff's attitudes toward SUD. Participants' reports also described an imbalance prior to the implementation, whereby SUD was rarely assessed but treatment was still initiated. One year after the implementation, an imbalance still existed, but in reverse: SUD was more frequently assessed, but treatment was difficult to initiate.

CONCLUSIONS

Despite indications of some ambivalence among staff regarding the necessity of the assessment and treatment guidelines, many participants considered it helpful to have a structured way to assess and treat SUD in this patient group. The imbalance between frequent assessment and infrequent treatment may have been due to difficulties transitioning patients across the "gap" between assessment and treatment. To bridge this gap, mental health services should make efforts to increase patients' insight concerning their SUD, flexibility in the administration of treatment, and the motivational skills of the health care staff working with this patient group. Participants considered important for enhancing treatment quality a shared knowledge base regarding SUD, and increased collaboration between different professions and between in- and outpatient services.

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person.

Welfare concerns associated with captive lions (Panthera leo) and the implications for commercial lion farms in South Africa

Breeding and housing wild animals in captive environments can pose challenges for their welfare. In South Africa, thousands of lions (Panthera leo) are bred and raised at commercial captive breeding facilities, so called 'lion farms', for use in tourism, trophy hunting and traditional medicine. To gain a better understanding of the potential welfare challenges faced by lions on farms we reviewed 91 peer-reviewed articles relating to lion welfare, identified via a systematic review of the scientific literature. Across these studies, we identified 170 different terms relating to negative behaviours and physical health afflictions. The majority of these terms were associated with disease and injury (124; 73%), followed by negative behaviours (19; 11%), negative mental experiences (15; 9%), nutritional concerns (7; 4%), and environmental challenges or discomfort arising from the animal's surroundings (5; 3%). Of the 91 articles, 32 (35%) focused on data concerning captive lions. Only two studies focused specifically on data obtained from lion farms in South Africa, whilst the remainder reported on data collected from zoos, wildlife parks, sanctuaries, game reserves and private ownership. Our preliminary review of the scientific literature draws attention to some of the challenges associated with caring for lions in captivity, and outlines the potential significance of these welfare challenges for commercial lion farms. Our data highlight the apparent lack of scientific research involving captive lion welfare generally, particularly data collected at commercial breeding facilities in South Africa and the consequences this could have for the welfare of thousands of lions within the industry.

Tolerogenic Artificial Antigen Presenting Cells for Selective Tolerance in Autoimmune Disease

Autoimmune diseases like multiple sclerosis (MS) and type 1 diabetes develop when autoreactive immune cells attack healthy cells and tissues. Current treatments are non-curative and leave patients immunocompromised. As an alternative, therapies that expand regulatory T cells (Tregs) are being actively explored to establish antigen-specific tolerance. We recently showed that an IL-2 immunocytokine (IL-2_IC), a fusion of an antibody to IL-2, preferentially engages and expands Tregs over effector T cells. As a more targeted approach to tolerize the immune system towards a specific autoantigen, we explored the design and therapeutic efficacy of a microparticle bearing an IL-2_IC and an MHC II/peptide complex on its surface (TolAPC).

Microparticles composed of a blend of PLGA and PBAE were loaded with rapamycin, and then chemically conjugated with IL-2_IC and MHC II I-A(b) tetramers loaded with a peptide derived from myelin oligodendrocyte glycoprotein (MOG). Characterized TolAPC were tested in a mouse model of MS, Experimental Autoimmune Encephalomyelitis (EAE). When administered prophylactically, TolAPC delayed EAE development and reduced severity compared to unconjugated controls, with 36.4% of mice remaining asymptomatic for the duration of the study. When administered therapeutically, TolAPC reversed symptomatic EAE. Clinical improvements correlated with a nearly two-fold increase in Tregs in the brain and spinal cord of TolAPC-treated mice compared to controls six days after treatment. Furthermore, administration of additional booster doses led to sustained amelioration of the disease.

Overall, TolAPC can selectively expand Tregs and provide both protection and treatment in an autoimmune mouse model.

Supported by grants from DoD (W81XWH-18-1-0735; W81XWH-21-1-0892), NIH (R01EB029455), and JDRF (1-INO-2020-923-A-N)

A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia

The emerging understanding of gut microbiota as 'metabolic machinery' influencing many aspects of physiology has gained substantial attention in the field of psychiatry. This is largely due to the many overlapping pathophysiological mechanisms associated with both the potential functionality of the gut microbiota and the biological mechanisms thought to be underpinning mental disorders. In this systematic review, we synthesised the current literature investigating differences in gut microbiota composition in people with the major psychiatric disorders, major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ), compared to 'healthy' controls. We also explored gut microbiota composition across disorders in an attempt to elucidate potential commonalities in the microbial signatures associated with these mental disorders. Following the PRISMA guidelines, databases were searched from inception through to December 2021. We identified 44 studies (including a total of 2510 psychiatric cases and 2407 controls) that met inclusion criteria, of which 24 investigated gut microbiota composition in MDD, seven investigated gut microbiota composition in BD, and 15 investigated gut microbiota composition in SZ. Our syntheses provide no strong evidence for a difference in the number or distribution (α-diversity) of bacteria in those with a mental disorder compared to controls. However, studies were relatively consistent in reporting differences in overall community composition (β-diversity) in people with and without mental disorders. Our syntheses also identified specific bacterial taxa commonly associated with mental disorders, including lower levels of bacterial genera that produce short-chain fatty acids (e.g. butyrate), higher levels of lactic acid-producing bacteria, and higher levels of bacteria associated with glutamate and GABA metabolism. We also observed substantial heterogeneity across studies with regards to methodologies and reporting. Further prospective and experimental research using new tools and robust guidelines hold promise for improving our understanding of the role of the gut microbiota in mental and brain health and the development of interventions based on modification of gut microbiota.

STEM-07. PRC2 MAINTAINS A CANCER STEM CELL PHENOTYPE IN GLIOBLASTOMA MULTIFORME VIA CHROMATIN MODIFICATION OF H3K27me3

Multi-potent stem-like cells (i.e. cancer stem cells, CSCs) are critical determinants of tumor propagation, therapeutic resistance, and recurrence in glioblastoma (GBM). Modifications in chromatin architecture play a fundamental role in the tumor cell phenotype of GBM. The polycomb repressor complex 2 (PRC2) is a key histone modifier that supports multi-potency and oncogenesis via H3K27 trimethylation (H3K27me3). Understanding how these epigenetic modifications cooperatively drive cancer cell stemness should unveil new targets for therapeutic development in GBM. Using a combination of next-generation sequencing, bioinformatics, and molecular approaches we identified EZH2, the catalytic domain of the PRC2 complex, as a critical mediator of reprograming events in GBM cells. We found that EZH2 is highly induced in response to transgenic Oct4/Sox2 with global increases in H3K27me3. Pharmacological inhibition of EZH2 diminishes self-renewal capacity of GBM neurospheres concurrent with a reduction in gene expression levels of markers and drivers of stemness. Furthermore, we identified and validated a set of 6 putative tumor suppressor genes repressed by Oct4 and Sox2 in a PRC2-dependent manner. We identified miR-217 as an EZH2 regulator in GBM cells and miR-217 reconstitution using advanced nanoparticle formulations re-activates the PRC2-repressed tumor suppressors, inhibited tumor growth and enhanced the effects of ionizing radiation in an orthotopic model of GBM. Taken together, these data show that PRC2-mediated chromatin changes in H3K27me3 help regulate the stem-cell phenotype induced by Oct4 and Sox2 in GBM cells and predict that targeting EZH2 could have therapeutic benefit in GBM.

222 Genetic reprogramming of merkel cell carcinoma and melanoma leads to increased MHC-I expression and antitumor immune activation in vitro and in vivo

Background

Merkel cell carcinoma (MCC) is a rare skin cancer with 46% disease-associated mortality and half of patients unresponsive to immune checkpoint inhibitors.1 2 MCC and melanomas often display decreased MHC class I (MHC-I) expression on the surface of cells, which prevents antigen recognition by T cells (”signal 1”) and hampers immune activation. We therefore sought to genetically reprogram cells to express their own costimulatory molecules (”signal 2”) and immunostimulatory cytokines (”signal 3”) to increase MHC-I expression and drive a targeted immune response.

Methods

We used biodegradable poly(beta-amino ester) nanoparticles (NPs) to co-deliver plasmids encoding a signal 2 molecule (4-1BBL) and two signal 3 molecules (IL-12 and IFNγ) to cancer cells. For in vitro evaluation of NPs we used two patient-derived MCC cell lines with low baseline MHC-I expression; MCC13 and UISO. Co-culture experiments were performed with human PBMCs or primary human natural killer (NK) cells. All in vitro analysis was performed 7 days following PBMC or NK cell addition. For in vivo evaluation, subcutaneous B16F10 mouse melanoma tumors were implanted in C57BL/6J mice and NPs were administered by direct injection into the tumor with and without intraperitoneal injection of αPD1. Tumors were harvested for analysis on day 16.

Results

Transfection with particles delivering the three plasmids to MCC13 and UISO increased MHC-I expression (mean fluorescence intensity) 1.6- and 5.0-fold, respectively, and MHC-II expression increased 1.6- and 6.3-fold, respectively (figure 1). In co-culture with human PBMCs, signal 2/3 particles resulted in increased leukocyte proliferation (4.6- and 6.1-fold increase, respectively) and led to significantly reduced MCC viability (10.6 and 1.6% vs control particles)(figure 2). When MCC13 cells were co-cultured with primary human NK cells, NK cell expansion increased 355-fold with 4-1BBL/IL-12 particles compared to control particles and was accompanied by 2.5% MCC13 cell viability, indicating a potent innate immune response with signal 2/3 NP administration in vitro (figure 3). Following evaluation of NPs in vivo, assessment of MHC-I and MHC-II expression in the melanoma tumors found increased expression with signal 2/3 NPs compared to control NPs (figure 4). When signal 2/3 NPs were administered in combination with αPD1 treatment, 4-1BBL/IL-12 NPs with αPD1 demonstrated improved survival compared to αPD1 treatment with control NPs (p=0.0010) (figure 5).

Abstract 222 Figure 1

Administration of signal 2/3 NPs to MCC13 and UISO cells led to increases in MHC-I and MHC-II expression after 7 days. MHC-I expression in transfected cells (red) and MHC-II expression in transfected cells (blue) compared to untreated control (black)

Abstract 222 Figure 2

Co-culture of transfected MCC cells with human PBMCs led to increases in CD45+ cells and reduced MCC cell viability after 7 days

Abstract 222 Figure 3

Co-culture of 4-1BBL/IL-12 transfected MCC13 cells with isolated CD56+ NK cells demonstrated robust NK-cell expansion and low MCC cell viability after 7 days

Abstract 222 Figure 4

Direct intratumoral injection with signal 2 and 3 NPs led to increases in MHC-I and MHC-II in cancer cells in vivo.

Abstract 222 Figure 5

NPs were administered intratumorally ± intraperitoneal aPD1 on day 9, 11, and 13 following B16F10 melanoma tumor implantation. 4-1BBL/IL12 particles in combination with αPD1 demonstrated a significant improvement in survival compared to control particles (Luc) with αPD1 (p=0.0010)

Conclusions

Together, these results show the ability of signal 2/3 NPs to reprogram MCC and melanoma cells, leading to increased MHC-I expression in vitro and in vivo, eliciting a productive immune response against cancer cells.

References

Hughes MP, Hardee ME, Cornelius LA, Hutchins LF, Becker JC, Gao L. Merkel cell carcinoma: epidemiology, target, and therapy. Curr Dermatol 2014;46–53.

Nghiem PT, Bhatia S, Lipson EJ, Kudchadkar RR, Miller NJ, Annamalai L, Berry S, Chartash EK, Daud A, Fling SP, Friedlander PA, Kluger HM, Kohrt HE, Lundgren L, Margolin K, Mitchell A, Olencki T, Pardoll DM, Reddy SA, Shantha EM, Sharfman WH, Sharon E, Shemanski LR, Shinohara MM, Sunshine JC, Taube JM, Thompson JA, Townson SM, Yearley JH, Topalian SL, Cheever MA. PD-1 blockade with pembrolizumab in advanced merkel-cell carcinoma. N Engl J Med 2016;374:2542–2552.

Experiences of UK African-Caribbean prostate cancer survivors of discharge to primary care

Objective: Black men are three times more likely to develop prostate cancer (PCa), to do so at a younger age and to experience a more aggressive form than White men. This study aims to understand the experiences of African-Caribbean men with respect to their discharge to primary care following successful PCa treatment and the challenges associated with survivorship.Design: Eight African-Caribbean men, who had been successfully treated for PCa, were recruited through the charity BME Cancer Communities. They participated in a focus group, which took place on the premises of the charity and was audio-recorded. The recording was transcribed and the data were analysed employing thematic analysis.Results: Three overarching themes were developed: Discharge - misconceptions and uncertainties; Survivorship - challenges and ways of coping; Black men and PCa: real and potential discrimination. Participants expressed concerns regarding the lack of information and clarity about what discharge meant, the quality of follow-up care, especially the levels of specialist knowledge among GPs, and the impact of side-effects, particularly erectile dysfunction (ED). Participants linked ED with stereotypes of Black male sexuality, particularly in relation to difficulties of expressing their emotions and psychological distress. African-Caribbean men face particular challenges in dealing with the side-effects of treatment for PCa, which are linked to socially-constructed ideas of masculinity.Conclusion: There needs to be a greater focus in primary care on understanding these issues and providing individualised culturally-sensitive care. In particular, GPs should be aware of sensitivities concerning help-seeking related to culturally-mediated understandings of masculinity.

564 Freedom from Urethral Catherisation – Using QI Methodology to Improve Patient Outcome and Experiences

Aim

To reduce catheter burden on patients who could instead be free of urethral catheter and taught intermittent self-catheterisation (ISC).

Method

2 PDSA (Plan, Do, Study, Act) cycles were performed over a 21-month period from February 2018 to November 2020. Using multiple nurse-led TWOC clinics, data was extracted using nurse-completed proformas and electronic patient records to determine: TWOC rate; urethral catheter-free rate; and ISC rate. Following baseline measurement, interventions were made, such as centralisation of TWOC services, emphasis on ISC teaching and the introduction of industry-nurse led clinics.

Results

At baseline, TWOC rate, urethral catheter-free rate and ISC rate were 55.7%, 68% and 28.2%, respectively. Following centralisation of TWOC services and emphasis on ISC teaching in Cycle 1, urethral catheter-free rate rose to 77.8% whilst ISC rate fell to 25%. Cycle 2 followed the introduction of industry-nurse led clinics. Following this, urethral catheter-free rate rose further to 81.6%, with ISC rate rising dramatically to 56.3%

Conclusions

To those capable, ISC frees patients of catheter burden and its sequalae. Evidently, a greater onus on ISC training will increase the number of patients left catheter-free.

123 Supporting A Learning System in Paediatric Emergency Pathways; Using Organisational Comparisons, Serious Incidents and Near Miss Events To Improve The Diagnosis And Treatment Of Testicular Torsion

Introduction

Scrotal pain is a common presentation to the emergency department requiring prompt investigation and management to identify testicular torsion. Using national data we aim to identify key suboptimal areas in the acute diagnosis and management of testicular torsion with a view to improving outcomes.

Method

A freedom of information request was made to all Trusts in England that manage testicular torsion. Serious Incidents (SI's) were analysed to see if those with Paediatric Emergency Departments fared better than those without. In addition, a qualitative thematic analysis of the NHS England Strategic Executive Information System database from 2007-2019 was undertaken, identifying common themes associated with orchidectomies and ‘near miss’ events in children.

Results

304 serious incidents were returned with 62 Orchidectomies and 242 Near Miss Events. Misdiagnosis of symptomatic testicle was not significant when comparing ED to specialists (OR = 1.46, p = 0.3842). Atypical presentation resulting in orchidectomy was significant when comparing ED to specialists (OR = 6, p = 0.0355). Near miss events are due to a variety of factors. There was no statistical significance in incidents when comparing ED's caring for all ages with Paediatric EDs U = 807.5, z = -1.124, p = 0.261.

Conclusions

There's a need for education in ED about atypical presentation of testicular torsion and examination of scrotum in cases of lower abdominal pain. It's also vital that specialist teams are cognisant of the standard operating procedures relevant to scrotal pain. Finally, there should be a drive for annual audit in Urology and ED units with regards to testicular torsion as SI's may be under-reported.

AB0872-HPR IMPACT OF COVID-19 ON A PHYSICAL ACTIVITY FEASIBILITY PILOT STUDY: THE PIPPRA EXPERIENCE

Background:

The PIPPRA (Physiotherapist-led Intervention to Promote Physical Activity in Rheumatoid Arthritis) project is a feasibility project examining the impact of a physical activity behaviour change intervention in people who have rheumatoid arthritis (RA). The PIPPRA study recruitment commenced in October 2019, with participant assessment and intervention commencing in November 2019. In the Republic of Ireland people who have RA are categorised as high risk category for Covid-19, due to immunosuppression [1], although this categorisation contrasts with EULAR’s provisional recommendations [2].

Objectives:

To examine the impact of the Covid-19 pandemic and public health restrictions on a pilot randomised controlled feasibility study in 2020.

Methods:

Participants (aged 18 years+, diagnosis of RA, independently mobile and low levels of physical activity [3]) were recruited from a rheumatology clinic at an urban hospital. Target recruitment was four participants per month for one year (N=48). Assessments were planned at baseline, eight and twenty-four weeks (N=144). Participants were randomised to intervention group or control group. The intervention group received four 1:1 sixty minute sessions with a physiotherapist (N=96). The intervention was delivered over eight weeks. Intervention and control groups received a physical activity information leaflet.

Results:

The Covid-19 pandemic and associated public health restrictions forced the study to be formally paused in April 2020 and the study formally resumed in August 2020. N=48 participants were recruited between October 2019 and March 2020 (six months). N=20 participants have commenced in the study, N=16 are awaiting baseline assessment, N=6 withdrew and N=6 were lost to follow-up prior to baseline. Trial protocol planned for the delivery of N=55 assessments and N=36 intervention sessions for participants who had commenced in the study. N=22 assessments and N=26 intervention sessions were delivered between November 2019 and March 2020. N=5 assessments and N=6 intervention sessions were conducted between August and October 2020. No assessment or intervention delivery occurred in November-December 2020 due to participant hesitancy in attending for assessment and/or intervention with increased public health restrictions. The impact of Covid-19 restrictions resulted in N=33 (60%) deviations from assessment protocol and N=10 (27%) deviations from intervention delivery protocol (Figure 1).

Figure 1.

Deviations from assessment and intervention protocol in the PIPPRA study

Conclusion:

The Covid-19 pandemic has had a significant impact on the delivery of the PIPPRA study. Feasibility study outcomes, including participant retention rate, and study delivery as per protocol, have been affected due to the Covid-19 pandemic. Participant reluctance to attend face-to-face sessions demonstrates the need to consider alternative methods of delivery, e.g. virtual delivery of interventions, where attending in person is not acceptable to participants [4], in future studies.

References:

[1]Health Service Executive. (2019). People at higher risk from COVID-19.Accessed 5th Jan 2020 https://www2.hse.ie/conditions/coronavirus/people-at-higher-risk.html.

[2]Landewé RB et al (2020). EULAR provisional recommendations for the management of rheumatic and musculoskeletal diseases in the context of SARS-CoV-2. Annals of the Rheumatic Diseases 79:851-858.

[3]Godin, G. (2011). The Godin-Shephard leisure-time physical activity questionnaire. The Health & Fitness Journal of Canada, 4(1):18-22.

[4]Inan, OT et al. (2020). Digitizing clinical trials. npj Digit. Med. 3:10.

Disclosure of Interests:

None declared

92 Reshaping the Diagnostic Pathways for Investigation of Haematuria During and After The COVID-19 Pandemic: Diagnostic Accuracy of Strategies for Detection of Bladder Cancer from The IDENTIFY Cohort Study

Introduction

Diagnostic haematuria services have been reduced due to the COVID-19 pandemic, compromising patient care, and necessitating a more pragmatic pathway.

Method

The IDENTIFY study was an international, prospective, multicentre cohort study of over 11,000 patients referred to secondary care for investigation of haematuria. Using this data, we developed strategies using combinations of imaging and cytology as triage tests to maximise cancer detection within a pragmatic pathway.

Results

8112 patients (74·4%) received an ultrasound or a CT urogram, with or without cytology. 5737 (70·7%) patients had visible haematuria (VH) and 2375 (29·3%) had non-visible haematuria (NVH). Diagnostic test performance was used to determine optimal age cut-offs for four proposed strategies. We recommended proceeding directly to transurethral resection of bladder tumour for patients of any age with positive triage tests for cancer. Patients with negative triage tests under 35-years-old with VH, or under 50-years-old with NVH can safely be discharged without undergoing flexible cystoscopy. The remaining patients may undergo flexible cystoscopy, with a greater priority for older patients to capture high risk bladder cancer.

Conclusions

We suggest diagnostic strategies in patients with haematuria, which focus on detection of bladder cancer, whilst reducing the burden to healthcare services in a resource-limited setting.

Influence of respiratory and inflammatory parameters preceding intubation on survival of patients with COVID-19 ARDS- A single centre retrospective analysis

It remains unclear if intubation and ventilation earlier in the disease course confers a survival advantage in acute respiratory distress syndrome. Our objective was to determine whether patients with COVID-19 who died following mechanical ventilation were more advanced in their disease compared to survivors. Forty-seven patients admitted directly to our centre received ventilation, of who 26 (57%) patients died. The rate of fall in SpO₂:FiO₂ ratio (p = 0.478) and increasing respiratory rate (p = 0.948) prior to IMV were similar between survivors and non-survivors. Our data support a trial of continuous positive airway pressure prior to IMV in patients with moderate-to-severe COVID-19 ARDS.

Comprehensive evaluation of methods for small extracellular vesicles separation from human plasma, urine and cell culture medium

One of the challenges that restricts the evolving extracellular vesicle (EV) research field is the lack of a consensus method for EV separation. This may also explain the diversity of the experimental results, as co-separated soluble proteins and lipoproteins may impede the interpretation of experimental findings. In this study, we comprehensively evaluated the EV yields and sample purities of three most popular EV separation methods, ultracentrifugation, precipitation and size exclusion chromatography combined with ultrafiltration, along with a microfluidic tangential flow filtration device, Exodisc, in three commonly used biological samples, cell culture medium, human urine and plasma. Single EV phenotyping and density-gradient ultracentrifugation were used to understand the proportion of true EVs in particle separations. Our findings suggest Exodisc has the best EV yield though it may co-separate contaminants when the non-EV particle levels are high in input materials. We found no 100% pure EV preparations due to the overlap of their size and density with many non-EV particles in biofluids. Precipitation has the lowest sample purity, regardless of sample type. The purities of the other techniques may vary in different sample types and are largely dependent on their working principles and the intrinsic composition of the input sample. Researchers should choose the proper separation method according to the sample type, downstream analysis and their working scenarios.

Examining the temporality of vitamin E acetate in illicit THC-containing e-cigarette, or vaping, products from a public health and law enforcement response to EVALI - Utah, 2018-2020

BACKGROUND

In the summer of 2019, e-cigarette, or vaping, product use-associated lung injury (EVALI) was detected in the United States. Multiple agencies reported illicit tetrahydrocannabinol (THC)-containing e-cigarette, or vaping, products containing vitamin E acetate (VEA) as a substance of concern.

METHODS

As an expansion of the Utah Department of Health's response to EVALI, the Utah Public Health Laboratory and the Utah Department of Public Safety screened 170 products from 96 seizures between October 2018 and January 2020. Using Pearson's correlation coefficient, we analyzed the temporal correlation of national, and Utah specific case counts, and the percentage of seizures indicating VEA by month.

RESULTS

The findings indicate strong and significant correlations between seizures indicating VEA and both the national (r = 0.70, p = 0.002) and Utah specific (r = 0.78, p < 0.001) case counts.

CONCLUSION

These findings underscore that VEA should not be added to e-cigarettes, or vaping, products and the importance of collaboration with law enforcement when responding to outbreaks associated with illicit substances.

Maxillofacial education in the time of COVID-19: the West Midlands experience

COVID-19 has accelerated a reliance on virtual technology for the delivery of postgraduate surgical education. We sought to develop a regional teaching programme with robust quality assurance. Webinars were delivered on a weekly basis by subspecialty experts using Zoom™ augmented with interactive polling software. Trainee feedback comprised Likert item rating on content and delivery, free text comments and self-assessed confidence levels using visual analogue scale (VAS) scores. A focus group was also convened and transcripts assessed with grounded theory analysis. Likert items revealed 442 (93.2%) positive responses regarding content and 642 (96.7%) positive responses regarding trainer delivery. There were statistically significant improvements in VAS scores across all programme content. Key themes from the focus group analysis were the pragmatics of delivering online education, issues surrounding trainer interactivity in the virtual world, the identification of the FRCS as a driving factor and a desire for case-based content and pre-learning of information (the ‘flipped classroom’). We are continuing to be reactive to trainee feedback in developing our online learning programme which will also include a regional Moodle-based virtual learning environment (VLE), the subject of future educational research in our region.

The gridded retarding ion drift sensor for the petitSat cubeSat mission

The Gridded Retarding Ion Drift Sensor (GRIDS) is a small sensor that will fly on the 6 U petitSat CubeSat. It is designed to measure the three-dimensional plasma drift velocity vector in the Earth's ionosphere. The GRIDS also supplies information about the ion temperature, ion density, and the ratio of light to heavy ions present in the ionospheric plasma. It utilizes well-proven techniques that have been successfully validated by similar instruments on larger satellite missions while meeting CubeSat-compatible requirements for low mass, size, and power consumption. GRIDS performs the functions of a Retarding Potential Analyzer (RPA) and an Ion Drift Meter (IDM) by combining the features of both types of instruments in a single package. The sensor alternates RPA and IDM measurements to produce the full set of measurement parameters listed above. On the petitSat mission, GRIDS will help identify and characterize a phenomenon known as plasma blobs (or enhancements).

Lack of efficient killing of purified dormant spores of Bacillales and Clostridiales species by glycerol monolaurate in a non-aqueous gel

Inactivation of Bacillales and Clostridiales spores is of interest, since some cause food spoilage and human diseases. A recent publication (mSphere 3: e00597-1, 2018) reported that glycerol monolaurate (GML) in a non-aqueous gel (GMLg) effectively killed spores of Bacillus subtilis, Bacillus cereus and Clostridioides difficile, and Bacillus anthracis spores to a lesser extent. We now show that (i) the B. subtilis spores prepared as in the prior work were impure; (ii) if spore viability was measured by diluting spores 1/10 in GMLg, serially diluting incubations 10-fold and spotting aliquots on recovery plates, there was no colony formation from the 1/10 to 1/1000 dilutions due to GMLg carryover, although thorough ethanol washes of incubated spores eliminated this problem and (iii) GMLg did not kill highly purified spores of B. subtilis, B. cereus, Bacillus megaterium and C. difficile in 3-20 h in the conditions used in the recent publication. GMLg also gave no killing of crude B. subtilis spores prepared as in the recent publication in 5 h but gave ~1·5 log killing at 24 h. Thus, GMLg does not appear to be an effective sporicide, although the gel likely inhibits spore germination and could kill spores somewhat upon long incubations. SIGNIFICANCE AND IMPACT OF THE STUDY: Given potential deleterious effects of spores of Bacillales and Clostridiales, there is an ongoing interest in new ways of spore killing. A recent paper (mSphere 3: e00597-1, 2018) reported that glycerol monolaurate (GML) in a non-aqueous gel (GMLg) effectively killed spores of many species. We now find that (i) the Bacillus subtilis spores prepared as in the previous report were impure and (ii) GMLg gave no killing of purified spores of Bacillales and Clostridiales species in ≤5 h under the published conditions. Thus, GMLg is not an effective sporicide, though may prevent spore germination or kill germinated spores.

The ALERT-B questionnaire: A screening tool for the detection of gastroenterological late effects after radiotherapy for prostate cancer

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ALERT-B provides an effective screening tool for gastroenterological late effects.

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84.4% and 95.7% of patients demonstrated complications at 6 and 12 months post-treatment.

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ROC curves at baseline indicated an AUC of 0.867 compared to the GSRS diarrhoea subscale.

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ROC curves at baseline indicated an AUC of 0.765 compared to the EPIC bowel subscale.

There is an increasing need to measure treatment-related side effects in normal tissues following cancer therapy. The ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) questionnaire is a screening tool that is composed of four items related specifically to bowel symptoms. Those patients that respond with a “yes” to any of these items are referred on to gastroenterologist in order to improve the long-term consequences of these side effects of radiological treatment. Here we wish to test the ability of this questionnaire to identify these subsequent gastroenterological complications by tracking prostate cancer patients that were positive with respect to ALERT-B. We also carry out receiver-operator curve (ROC) analysis for baseline data for an overall ALERT-B questionnaire score with respect to subscale data for the Gastrointestinal Symptom Rating Scale (GSRS) and the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. 84.4% and 95.7% of patients identified by the ALERT-B questionnaire demonstrated complications diagnosed at 6 and 12 months post-treatment, respectively. ROC curve analysis of baseline data showed that ALERT-B detected clinically relevant levels of side effects established at baseline by the GSRS diarrhoea subscale (AUC = 0.867, 95% CI = 0.795 to 0.926) and at the minimally important level of side effects for the EPIC bowel subscale (AUC = 0.765, 95% CI = 0.617 to 0.913). These results show that ALERT-B provides a simple and effective screening tool for identifying gastroenterological complications after treatment for prostate cancer.

Longer-term effectiveness of systemic family therapy compared with treatment as usual for young people after self-harm: An extended follow up of pragmatic randomised controlled trial

BACKGROUND

Self-harm in adolescents is common and repetition frequent. Evidence for effective interventions to reduce self-harm is limited. Long term follow-up of existing studies is rare.

METHODS

Extended follow up, from 18 to at least 36-months, of the SHIFT trial: a pragmatic, multi-centre, individually-randomised, controlled trial involving young people (11-17) who had self-harmed at least twice and presented to Child & Adolescent Mental Health Services (CAMHS). SHIFT evaluated manualised family therapy (FT) versus treatment as usual (TAU) in reducing repetition of self-harm leading to hospital attendance 18 months post-randomisation.We obtained ONS mortality data, adult mental health data, and further details of hospital attendance from routine Hospital Episode Statistics (HES) data plus researcher follow-up. We assessed longer-term differences in outcome using multivariable Cox Proportional Hazards regression analysis, and assessed all-cause mortality and morbidity relating to hospital attendances for reasons other than self-harm.

STUDY REGISTRATION

ISRCTN 59793150.

OUTCOMES

The original sample of 832 were randomised between April 2010 and December 2013. Extended follow-up continued until February 2017 for a median 55·4 months (range 0-82·5 months), providing post 18-month data for 804 (96·6%) participants, of whom 785 (94·4%) had a minimum of 36-months follow-up.There was no evidence of a between-group difference in the primary outcome during the extended follow-up period (Hazard Ratio (HR) 1·03; 95% CI: 0·83, 1·28; p-value=0·78), consistent with our findings in the original trial with 18 months follow-up (HR 1·14, 95% CI 0·87, 1·49; p-value 0·33). There was a reduced rate of self-harm in older participants aged 15-17 (HR 0·7, 95% CI 0·56, 0·88), as compared with those aged 11-14; and significantly increased rates of self-harm in participants whose index episode combined self-injury and poisoning (HR 1·8, 95% CI 1·2, 2·7). Two deaths were reported during the extended follow up period.

INTERPRETATION

For adolescents referred to CAMHS after self-harm, having self-harmed at least once before, trial FT confers no benefits over TAU in reducing subsequent hospitalisation for self-harm over 18 months or 36 months.

FUNDING

NIHR HTA Reference: 07/33/01.

SCIDOT-08. CHILDREN’S BRAIN TUMOUR DRUG DELIVERY CONSORTIUM (CBTDDC)

INTRODUCTION

The brain tumour community has seen significant progress in the discovery of new therapeutic targets and anticancer drugs. Unfortunately, advances in how to deliver drugs to the brain lag behind. The blood-brain barrier restricts the entry of many small-molecule drugs and nearly all large molecule drugs that have been developed to treat brain disorders.

METHODS

Following an international CNS drug delivery workshop in 2016, we were awarded funding from Children with Cancer UK to launch the Children’s Brain Tumour Drug Delivery Consortium (CBTDDC; www.cbtddc.org; @cbtddc).

RESULTS

The CBTDDC launched in 2017 (in Europe and the US) to raise awareness of the challenge of drug delivery in childhood brain tumours, and to initiate and strengthen research collaborations to accelerate the development of drug delivery systems. We ran a Workshop on Drug Delivery to the Brain, attracting 52 delegates from the UK, Belgium, Spain and Portugal. We liaised with UK-based funders over the drug delivery agenda, and with UK policy makers. In the US, we jointly organised the SIGN2019 meeting and we are currently liaising with the leads of Project ‘All In’ DIPG about how we can lend our support to this project. As of June 2019, 150 individuals have registered with the consortium, representing researchers, clinicians, charities, patient groups and industry. These stakeholders represent 70 research institutions, covering 15 countries (France, UK, Italy, Sweden, The Netherlands, USA, Greece, Germany, Belgium, Cuba, Denmark, Spain, Portugal, Israel and Egypt). We host a freely accessible online collaborative research database, containing the details of over 70 researchers.

CONCLUSION

We believe that collaboration between clinicians and multi-disciplinary researchers is vital to solving the brain tumour drug delivery challenge. We hope to raise awareness of the CBTDDC, and to extend our invitation for collaborators to join the consortium, through SCIDOT’s unrivalled drug delivery platform.

A new energy spectrum reconstruction method for time-of-flight diagnostics of high-energy laser-driven protons

The Time-of-Flight (TOF) technique coupled with semiconductorlike detectors, as silicon carbide and diamond, is one of the most promising diagnostic methods for high-energy, high repetition rate, laser-accelerated ions allowing a full on-line beam spectral characterization. A new analysis method for reconstructing the energy spectrum of high-energy laser-driven ion beams from TOF signals is hereby presented and discussed. The proposed method takes into account the detector's working principle, through the accurate calculation of the energy loss in the detector active layer, using Monte Carlo simulations. The analysis method was validated against well-established diagnostics, such as the Thomson parabola spectrometer, during an experimental campaign carried out at the Rutherford Appleton Laboratory (UK) with the high-energy laser-driven protons accelerated by the VULCAN Petawatt laser.

The relationship between physical activity levels and symptoms of depression, anxiety and stress in individuals with alopecia Areata

Background

Alopecia Areata (AA) is an autoimmune condition that is characterised by non-scarring hair loss. Its aesthetic repercussions can lead to profound changes in psychological well-being. Although physical activity (PA) has been associated with better mental health outcomes in diverse populations, the association in individuals with AA has not been established. The aim of this study was to examine the associations between PA and mental health outcomes in individuals with AA to inform intervention strategies for this specific population.

Methods

A cross-sectional study was conducted among individuals who were diagnosed with AA. A total of 83 respondents aged (40.95 ± 13.24 years) completed a self-report questionnaire consisting of International Physical Activity Questionnaire-Short Form (IPAQ-SF) and the Depression and Anxiety Stress Scale (DASS-21). Three-way contingency Chi-square analyses were used to determine the associations between PA, mental health outcomes and participants with hair loss of more than 50% on the scalp.

Results

81.9% of the participants did not meet PA guidelines. Participants with hair loss of more than 50% on the scalp, and who did not meet PA guidelines, were significantly more likely to experience symptoms of severe depression (p = .003), moderate anxiety (p = .04) and mild stress (p = .003) than those who met guidelines

Conclusion

Findings suggest that increased PA participation in AA individuals with severe hair loss is associated with improved mental health status. Intervention efforts for this specific population should consider barriers and enablers to PA participation as they face challenges that differ from the general population.

Quality of Clinical Practice Guidelines for Management of Limb Amputations: A Systematic Review

BACKGROUND

The quality of clinical practice guidelines (CPGs) is important to ensure guideline adoption by clinicians.

PURPOSE

The aim of this review was to identify CPGs for the management of limb amputations, appraise the quality of CPGs, and synthesize recommendations from comprehensive CPGs of high quality.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, PEDro, guideline-specific websites, websites for associations or networks for people with amputations, and Google Scholar were searched from April 2007 to April 2017.

STUDY SELECTION

Publications were included if they were CPGs or consensus statements/standards endorsed by a certified organization, covered the management of limb amputations, were freely accessible, and were written in English.

DATA EXTRACTION

Two reviewers independently screened titles and abstracts for eligible CPGs and rated the quality of CPGs using the Appraisal of Guidelines Research and Evaluation (AGREE-II) instrument.

DATA SYNTHESIS

Of the 15 included CPGs, 11 were of low to moderate quality and 4 were of high quality. Mean (or median) domain scores on AGREE-II were as follows: 83% for domain 1 (scope and purpose), 61% for domain 2 (stakeholder involvement), 7% for domain 3 (rigor of development), 65% for domain 4 (clarity and presentation), 24% for domain 5 (applicability), and 21% for domain 6 (editorial independence). Strong recommendations from comprehensive and high-quality CPGs were few and focused on the development of individualized treatment plans, exercises for improving physical function and the ability to perform activities of daily living, and the assessment of physical function and prognostic factors.

LIMITATIONS

CPGs that were not written in English were excluded. Final recommendations from CPGs might differ if different criteria were used. Low domain scores on the AGREE-II might be due to poor reporting rather than poor methodology in the CPG development process.

CONCLUSIONS

Few CPGs for the management of limb amputations were of high quality, and few recommendations were strong. To improve the quality of future CPGs, guideline developers should report funding and competing interests of members, provide information to aid in the practical application of CPGs, and use a systematic approach to search for evidence and derive strength of recommendations.

Hydrogen sulfide: Therapeutic or injurious in ischemic stroke?

Hydrogen sulfide (H2S) has been identified as a vasodilatory, neuromodulatory, and anti-inflammatory gasotransmitter with antioxidant properties. Studies focused in cardiac tissue suggest H2S functions as a protective agent; however in the central nervous system (CNS) the effects of H2S during states of stress or injury, such as stroke, remain controversial. Currently, the application of H2S donors and modulators in stroke depends on the type of H2S donor and the timing of the therapy.