Incorporating ecology into gene drive modelling.

Gene drive technology, in which fast-spreading engineered drive alleles are introduced into wild populations, represents a promising new tool in the fight against vector-borne diseases, agricultural pests and invasive species. Due to the risks involved, gene drives have so far only been tested in laboratory settings while their population-level behaviour is mainly studied using mathematical and computational models. The spread of a gene drive is a rapid evolutionary process that occurs over timescales similar to many ecological processes. This can potentially generate strong eco-evolutionary feedback that could profoundly affect the dynamics and outcome of a gene drive release. We, therefore, argue for the importance of incorporating ecological features into gene drive models. We describe the key ecological features that could affect gene drive behaviour, such as population structure, life-history, environmental variation and mode of selection. We review previous gene drive modelling efforts and identify areas where further research is needed. As gene drive technology approaches the level of field experimentation, it is crucial to evaluate gene drive dynamics, potential outcomes, and risks realistically by including ecological processes.

College students' virtual and in-person drinking contexts during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in pronounced changes for college students, including shifts in living situations and engagement in virtual environments. Although college drinking decreased at the onset of the pandemic, a nuanced understanding of pandemic-related changes in drinking contexts and the risks conferred by each context on alcohol use and related consequences have yet to be assessed. METHODS: Secondary data analyses were conducted on screening data from a large parent clinical trial assessing a college student drinking intervention (N = 1669). Participants across six cohorts (from Spring 2020 to Summer 2021) reported on the frequency of drinking in each context (i.e., outside the home, home alone, home with others in-person, and home with others virtually), typical amount of drinking, and seven alcohol-related consequence subscales. RESULTS: Descriptive statistics and negative binomial regressions indicated that the proportion and frequency of drinking at home virtually with others decreased, while drinking outside the home increased from Spring 2020 to Summer 2021. Limited differences were observed in the proportion or frequency of individuals drinking at home alone or at home with others in-person. Negative binomial and logistic regressions indicated that the frequency of drinking outside the home was most consistently associated with more alcohol-related consequences (i.e., six of the seven subscales). However, drinking at home was not without risks; drinking home alone was associated with abuse/dependence, personal, social, hangover, and social media consequences; drinking home with others virtually was associated with abuse/dependence and social consequences; drinking home with others in-person was associated with drunk texting/dialing. CONCLUSION: The proportion and frequency of drinking in certain contexts changed during the COVID-19 pandemic, although drinking outside the home represented the highest risk drinking context across the pandemic. Future prevention and intervention efforts may benefit from considering approaches specific to different drinking contexts.

Anopheles homing suppression drive candidates exhibit unexpected performance differences in simulations with spatial structure.

Recent experiments have produced several Anopheles gambiae homing gene drives that disrupt female fertility genes, thereby eventually inducing population collapse. Such drives may be highly effective tools to combat malaria. One such homing drive, based on the zpg promoter driving CRISPR/Cas9, was able to eliminate a cage population of mosquitoes. A second version, purportedly improved upon the first by incorporating an X-shredder element (which biases inheritance towards male offspring), was similarly successful. Here, we analyze experimental data from each of these gene drives to extract their characteristics and performance parameters and compare these to previous interpretations of their experimental performance. We assess each suppression drive within an individual-based simulation framework that models mosquito population dynamics in continuous space. We find that the combined homing/X-shredder drive is actually less effective at population suppression within the context of our mosquito population model. In particular, the combined drive often fails to completely suppress the population, instead resulting in an unstable equilibrium between drive and wild-type alleles. By contrast, otherwise similar drives based on the nos promoter may prove to be more promising candidates for future development than originally thought.

Sex and Gender Bias as a Mechanistic Determinant of Cardiovascular Disease Outcomes.

Defined as a prejudice either for or against something, biases at the provider, patient, and societal level all contribute to differences in cardiovascular disease recognition and treatment, resulting in outcome disparities between sexes and genders. Provider bias in the under-recognition of female-predominant cardiovascular disease and risks might result in underscreened and undertreated patients. Furthermore, therapies for female-predominant phenotypes including nonobstructive coronary artery disease and heart failure with preserved ejection fraction are less well researched, contributing to undertreated female patients. Conversely, women are less likely to seek urgent medical attention, potentially related to societal bias to put others first, which contributes to diagnostic delays. Furthermore, women are less likely to have discussions around risk factors for coronary artery disease compared with men, partially because they are less likely to consider themselves at risk for heart disease. Provider bias in interpreting a greater number of presenting symptoms, some of which have been labelled as "atypical," can lead to mislabelling presentations as noncardiovascular. Furthermore, providers might avoid discussions around certain therapies including thrombolysis for stroke, and cardiac resynchronization therapy in heart failure, because it is incorrectly assumed that women are not interested in pursuing options deemed more invasive. To mitigate bias, organizations should aim to increase the visibility and involvement of women in research, health promotion, and clinical and leadership endeavours. More research needs to be done to identify effective interventions to mitigate sex and gender bias and the resultant cardiovascular outcome discrepancies.

Redo Transcatheter Aortic Valve Implantation with the ALLEGRA Transcatheter Heart Valve: Insights from Bench Testing.

PURPOSE: Failure of transcatheter heart valves (THV) may potentially be treated with repeat transcatheter aortic valve implantation (redo TAVI). We assessed hydrodynamic performance, stability and pinwheeling utilizing the ALLEGRA (New Valve Technology, Hechingen, Germany) THV, a CE approved and marketed THV in Europe, inside different THVs. METHODS: Redo TAVI was simulated with the 27 mm ALLEGRA THV at three implantation depths (-4 mm, 0 mm and +4 mm) in seven different 'failed' THVs: 26 mm Evolut Pro, 25 mm Lotus, 25 mm JenaValve, 25 mm Portico, 23 mm Sapien 3, 27 mm ALLEGRA and M ACURATE neo. Hydrodynamic evaluation was performed according to International Standards Organization 5840-3:2021. RESULTS: The ALLEGRA THV was stable with acceptable performance (gradient <20 mmHg, effective orifice area >2 cm2, and regurgitant fraction <20%) in all 'failed' THVs except the Evolut Pro at -4 mm implantation depth. In this configuration, the outflow of the ALLEGRA frame was constrained by the Evolut Pro THV and the ALLEGRA leaflets were unable to fully close. Pinwheeling was severe for the ALLEGRA in Evolut Pro. The neo-skirt was higher with taller frame THVs. CONCLUSION: The ALLEGRA THV had favorable hydrodynamic performance, stability and pinwheeling in all redo TAVI samples except the Evolut Pro at low implantation depth with compromised function. The choice of initial THV may have late implications on new THV choice and function.

[Opportunities and challenges of active patient involvement in clinical research in Germany - from the perspectives of a patient representative, a clinical researcher and two staff members of research funding management]. / Chancen und Herausforderungen der aktiven Beteiligung von Patient*innen an klinischer Forschung in Deutschland ­ Eine Betrachtung aus den Perspektiven eines Patient*innenvertreters, einer klinischen Forscherin und zweier Mitarbeiterinnen des Forschungsfördermanagements.

BACKGROUND: Active involvement of patients in clinical research is increasingly demanded in Germany. It has great potential to increase the quality and relevance of research and to contribute to patient empowerment. However, patients, researchers and research funders have experienced that the implementation of patient involvement is accompanied by cultural, practical and personal challenges. The aim of this article is to discuss the opportunities and challenges of patient involvement in Germany from the perspective of the stakeholders involved. METHOD: A patient representative, a clinical researcher and two staff members from research funding management were invited to discuss the opportunities and challenges of patient involvement. Their perspectives were recorded in two written open survey rounds. The answers were analyzed using qualitative content analysis. RESULT: In the opinion of the stakeholders involved, the increasing involvement of patients in clinical research is an opportunity to promote the practical relevance of research and the implementation of studies, to increase their acceptance by the target group and to improve the uptake of research results in practice. However, the implementation of patient involvement was also perceived as challenging. They described problems with regard to the acquisition and selection of patients, the training of the patients and the specifications and support structures for the implementation of patient involvement. DISCUSSION: While patient involvement in clinical research offers great potential, the development of appropriate structures and framework conditions for its implementation is still virtually unestablished in Germany. This needs to include, among other things, creating a broader awareness of the potential of patient involvement, developing training programs for patients and researchers, providing sufficient, mainly project-independent resources and ensuring regular evaluations.

Design and analysis of CRISPR-based underdominance toxin-antidote gene drives.

CRISPR gene drive systems offer a mechanism for transmitting a desirable transgene throughout a population for purposes ranging from vector-borne disease control to invasive species suppression. In this simulation study, we assess the performance of several CRISPR-based underdominance gene drive constructs employing toxin-antidote (TA) principles. These drives disrupt the wild-type version of an essential gene using a CRISPR nuclease (the toxin) while simultaneously carrying a recoded version of the gene (the antidote). Drives of this nature allow for releases that could be potentially confined to a desired geographic location. This is because such drives have a nonzero-invasion threshold frequency required for the drive to spread through the population. We model drives which target essential genes that are either haplosufficient or haplolethal, using nuclease promoters with expression restricted to the germline, promoters that additionally result in cleavage activity in the early embryo from maternal deposition, and promoters that have ubiquitous somatic expression. We also study several possible drive architectures, considering both "same-site" and "distant-site" systems, as well as several reciprocally targeting drives. Together, these drive variants provide a wide range of invasion threshold frequencies and options for both population modification and suppression. Our results suggest that CRISPR TA underdominance drive systems could allow for the design of flexible and potentially confinable gene drive strategies.

Suppression gene drive in continuous space can result in unstable persistence of both drive and wild-type alleles.

Rapid evolutionary processes can produce drastically different outcomes when studied in panmictic population models vs. spatial models. One such process is gene drive, which describes the spread of "selfish" genetic elements through a population. Engineered gene drives are being considered for the suppression of disease vectors or invasive species. While laboratory experiments and modelling in panmictic populations have shown that such drives can rapidly eliminate a population, it remains unclear if these results translate to natural environments where individuals inhabit a continuous landscape. Using spatially explicit simulations, we show that the release of a suppression drive can result in what we term "chasing" dynamics, in which wild-type individuals recolonize areas where the drive has locally eliminated the population. Despite the drive subsequently reconquering these areas, complete population suppression often fails to occur or is substantially delayed. This increases the likelihood that the drive is lost or that resistance evolves. We analyse how chasing dynamics are influenced by the type of drive, its efficiency, fitness costs, and ecological factors such as the maximal growth rate of the population and levels of dispersal and inbreeding. We find that chasing is more common for lower efficiency drives when dispersal is low and that some drive mechanisms are substantially more prone to chasing behaviour than others. Our results demonstrate that the population dynamics of suppression gene drives are determined by a complex interplay of genetic and ecological factors, highlighting the need for realistic spatial modelling to predict the outcome of drive releases in natural populations.

[Patient and public involvement in clinical research: An introduction]. / Aktive Beteiligung von Patient*innen an klinischer Forschung ­ Eine Einführung.

Usually, patients participating in clinical trials have a passive role as test persons. This creates a risk that patients' needs and interests are not reflected in clinical research. The aim of the present paper is to give an introduction to patient involvement in clinical research. It is based on an exploratory literature research and our own experiences with patient involvement. By actively involving patients in the design, conduct and translation of clinical trials, research and healthcare can be better tailored to meet the patients' needs. Patient involvement has the potential to enhance the quality and relevance of research, support patient empowerment and contribute to the democratisation of research processes. There are different methods to involve patients in research, which are often differentiated as consultation, cooperation and user-led research. Methods, time of involvement and persons to be involved should be chosen to fit the aims of the involvement. While cultural, practical and personal barriers could hinder patient involvement, there are several strategies that enable effective involvement: defining the aims of the involvement, clarifying motivation and expectations as well as roles and the form of cooperation, offering training, planning sufficient resources, involving patients from the start and communicating the benefits of involvement.

[Older patients' involvement in research (INVOLVE-Clin): a study protocol]. / Aktive Beteiligung von älteren Patient*innen an klinischer Forschung (INVOLVE-Clin): Ein Studienprotokoll.

INTRODUCTION: Patient involvement in health research is an integral part of health care in many countries. It promotes the relevance and quality of research and increases the meaningfulness of research results. Meanwhile, the value of patient involvement has also been recognised in Germany. The lack of a common understanding of patient involvement and appropriate methods make implementation difficult. In Germany, patients are still rarely involved in the planning and conduct of health research. Vulnerable patient groups such as the elderly and the very old are considered particularly challenging for researchers in active patient involvement due to their special needs, which is why they are often neglected. Especially nursing home residents suffer from a variety of health impairments which are accompanied by a high number of prescription drugs and adverse events and can therefore make patient involvement more difficult. The present project aims to test the method of patient advisory boards for the involvement of nursing home residents. Using the design of a clinical trial to optimise medication for nursing home residents as a case study, we will assess the feasibility of the method for this target group. We will also install a patient advocate as moderator of the advisory board. The study plan is described in the present study protocol. METHODS: Two patient advisory boards with nursing home residents will be established. With a patient advocate acting as moderator, the essential elements of a clinical trial to optimise medication will be discussed and passed on to the study planning team via the patient advocate. The overall topic of the clinical trial is the optimisation of medication in cardiovascular disease. The nursing home residents are informed about the contents and ideas of the study to be planned and the interests of the researchers, respectively, and will discuss the proposals of the study planning team. Nursing home residents', the patient advocate's and the researchers' expectations and experiences will be examined in individual interviews. DISCUSSION: The study will provide a potentially suitable method to involve nursing home residents in the research process. The jointly developed study design will be incorporated into a new project proposal. The results will be used to inform the development of a German handbook on active public and patient involvement.

Performance analysis of novel toxin-antidote CRISPR gene drive systems.

BACKGROUND: CRISPR gene drive systems allow the rapid spread of a genetic construct throughout a population. Such systems promise novel strategies for the management of vector-borne diseases and invasive species by suppressing a target population or modifying it with a desired trait. However, current homing-type drives have two potential shortcomings. First, they can be thwarted by the rapid evolution of resistance. Second, they lack any mechanism for confinement to a specific target population. In this study, we conduct a comprehensive performance assessment of several new types of CRISPR-based gene drive systems employing toxin-antidote (TA) principles, which should be less prone to resistance and allow for the confinement of drives to a target population due to invasion frequency thresholds. RESULTS: The underlying principle of the proposed CRISPR toxin-antidote gene drives is to disrupt an essential target gene while also providing rescue by a recoded version of the target as part of the drive allele. Thus, drive alleles tend to remain viable, while wild-type targets are disrupted and often rendered nonviable, thereby increasing the relative frequency of the drive allele. Using individual-based simulations, we show that Toxin-Antidote Recessive Embryo (TARE) drives targeting an haplosufficient but essential gene (lethal when both copies are disrupted) can enable the design of robust, regionally confined population modification strategies with high flexibility in choosing promoters and targets. Toxin-Antidote Dominant Embryo (TADE) drives require a haplolethal target gene and a germline-restricted promoter, but they could permit faster regional population modification and even regionally confined population suppression. Toxin-Antidote Dominant Sperm (TADS) drives can be used for population modification or suppression. These drives are expected to spread rapidly and could employ a variety of promoters, but unlike TARE and TADE, they would not be regionally confined and also require highly specific target genes. CONCLUSIONS: Overall, our results suggest that CRISPR-based TA gene drives provide promising candidates for flexible ecological engineering strategies in a variety of organisms.

Local anesthetic injections with or without steroid for chronic non-cancer pain: a protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Steroids are often combined with local anesthetic (LA) and injected to reduce pain associated with various chronic non-cancer pain (CNCP) complaints. The biological rationale behind injection of a steroid solution is unclear, and it is uncertain whether the addition of steroids offers any additional benefits over injection of LA alone. We propose to conduct a systematic review and meta-analysis to summarize the evidence for using steroids and LA vs. LA alone in the treatment of CNCP. METHODS: An experienced librarian will perform a comprehensive search of EMBASE, MEDLINE, and the Cochrane Central Registry of Controlled Trials (CENTRAL) databases with search terms for clinical indications, LA, and steroid agents. We will review bibliographies of all relevant published reviews in the last 5 years for additional studies. Eligible trials will be published in English and randomly allocate patients with CNCP to treatment with steroid and LA injection therapy or injection with LA alone. We will use the guidelines published by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to inform the outcomes that we collect and present. Teams of reviewers will independently and in duplicate assess trial eligibility, abstract data, and assess risk of bias among eligible trials. We will prioritize intention to treat analysis and, when possible, pool outcomes across trials using random effects models. We will report our findings as risk differences, weighted mean differences, or standardized mean differences for individual outcomes. Further, to ensure interpretability of our results, we will present risk differences and measures of relative effect for pain reduction based on anchor-based minimally important clinical differences. We will conduct a priori defined subgroup analyses and use the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the certainty of the evidence on an outcome-by-outcome basis. DISCUSSION: Our review will evaluate both the effectiveness and the adverse events associated with steroid plus LA vs. LA alone for CNCP, evaluate the quality of the evidence using the GRADE approach, and prioritize patient-important outcomes guided by IMMPACT recommendations. Our results will facilitate evidence-based management of patients with chronic non-cancer pain and identify key areas for future research. TRIAL REGISTRATION: PROSPERO CRD42015020614.