The in vitro generation of human cardiomyocytes derived from induced pluripotent stem cells (iPSC) is of great importance for cardiac disease modeling, drug-testing applications and for regenerative medicine. Despite the development of various cultivation strategies, a sufficiently high degree of maturation is still a decisive limiting factor for the successful application of these cardiac cells. The maturation process includes, among others, the proper formation of sarcomere structures, mediating the contraction of cardiomyocytes. To precisely monitor the maturation of the contractile machinery, we have established an imaging-based strategy that allows quantitative evaluation of important parameters, defining the quality of the sarcomere network. iPSC-derived cardiomyocytes were subjected to different culture conditions to improve sarcomere formation, including prolonged cultivation time and micro patterned surfaces. Fluorescent images of α-actinin were acquired using super-resolution microscopy. Subsequently, we determined cell morphology, sarcomere density, filament alignment, z-Disc thickness and sarcomere length of iPSC-derived cardiomyocytes. Cells from adult and neonatal heart tissue served as control. Our image analysis revealed a profound effect on sarcomere content and filament orientation when iPSC-derived cardiomyocytes were cultured on structured, line-shaped surfaces. Similarly, prolonged cultivation time had a beneficial effect on the structural maturation, leading to a more adult-like phenotype. Automatic evaluation of the sarcomere filaments by machine learning validated our data. Moreover, we successfully transferred this approach to skeletal muscle cells, showing an improved sarcomere formation cells over different differentiation periods. Overall, our image-based workflow can be used as a straight-forward tool to quantitatively estimate the structural maturation of contractile cells. As such, it can support the establishment of novel differentiation protocols to enhance sarcomere formation and maturity.

Keywords: Maturation; Sarcomere network; Super resolution microscopy; iPSC cardiomyocytes.

Introduction: We define a designated data analytics workflow for the evaluation of stability experiments, which takes all data situations into account. This complements the evaluation described by the CLSI EP25 [1] guideline by including a targeted exception handling algorithm and thus allows one to automatically evaluate stability data based on linear regression analysis.

Description: The evaluation of stability experiments based on regression analysis requires the calculation of the confidence interval of the regression line. The stability time is estimated at the intersection of the confidence interval with the acceptance criterion. This approach results in solving a quadratic equation, with factors that depend on the estimated intercept, slope, the measurement variability and the chosen timepoints. When defining an automated data analytics workflow for this problem, the different cases for the solutions of the quadratic equation must be considered. For some data situations there might be no solution at all, other data situations result in a negative and a positive solution and finally there might be even two positive solutions. All these cases have to be considered for the choice of the right solution to become the estimated stability time. The CLSI EP25 [1] guideline on stability evaluation of in vitro diagnostic reagents addresses this problem only superficially and might even lead to incorrect results for some specific data scenarios.

Results: We evaluate all possible data scenarios and provide examples for each. Based on the gained theoretical insights, we define a designated data analytics workflow and visualize it with a flowchart. By following this flowchart one can implement an automated analysis workflow, targeting all data scenarios with the appropriate exception handling.

Discussion: We deduce that the description for obtaining stability times according to CLSI EP25 is not fully adequate, as it addresses only best-case scenarios. However, for automated data analytics workflows all possible data situations have to be considered. With the here presented workflow one can program automated data analytics pipelines, which ensure that the right stability time is obtained, in case it exists. In addition all exceptions, where no stability times are present, are addressed in the right way and it provides hints as to the failure reason.

Keywords: CLSI EP25; CLSI, Clinical and Laboratory Standards Institute; Data analytics workflow; EFLM, European Federation of Clinical Chemistry and Laboratory Medicine; ICH, International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use; IVD, In-Vitro Diagnostic; QC, Quality Control; Reagent stability; Sample stability; Stability studies; Var(Residual), Residual Variance.

Giant-cell tumor of bone is a rare, locally aggressive and rarely metastasizing primary bone tumor. The mainstay of treatment remains controversial and is decided by the balance between adequate surgical margin and sufficient adjacent joint function. Although curettage with a high-speed burr and local adjuvants can maintain normal joint function, many reports have revealed a high local recurrence rate. Conversely, en bloc resection and reconstruction with prostheses for highly aggressive lesions have reportedly lower local recurrence rates and poorer functional outcomes. Denosumab-a full human monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand-was approved by the Food and Drug Authority in 2013 for use in surgically unresectable or when resection is likely to result in severe morbidity for skeletally mature adolescents and adults with giant-cell tumor of bone. However, subsequent studies have suggested that the local recurrence rate would be increased by preoperative use of denosumab. In systematic reviews of the local recurrence rate after preoperative use of denosumab, conclusions vary due to the small sample sizes of the studies reviewed. Therefore, controversy regarding the treatment of giant-cell tumor of bone is ongoing. Here, this review elucidates the management of giant-cell tumor of bone, especially with the local adjuvant and neoadjuvant use of denosumab, and presents the current, evidence-based treatment for giant-cell tumor of bone.

Keywords: bone tumors; denosumab; giant-cell tumor of bone; surgery.

According to the definition that the European Commission (2001) offered us, corporate social responsibility is a set of measures that an organization can adapt, to improve the well-being of its stakeholders and promote the balance of economic, social, and environmental performance. The stakeholder theory clarifies that this decision-making must take into consideration all groups of people, being the only way of having a proportional benefit. Based on this premise, in this study, we intend to unravel the main determinants of corporate social responsibility in 63 Portuguese companies. To accomplish that, we used panel data, withdrawn from the SABI database, in the period comprehended between 2008 and 2018, applying the Probit model and the dynamic GMM for robustness check. The sample is composed of 42 companies that find themselves listed in the Portuguese stock exchange and 21 that do not. We can verify that the outcomes allow the analyses of nine variables, among them, only the audit, the asset rotation ratio, the debt ratio, the size, age, and financial autonomy show themselves as statistically positive in the implementation of corporate social responsibility practices. Even though the outcomes were not what we initially predicted, they revealed the positive impact of such practices. We consider them necessary and a reality that companies should pursue, even for the gains of capital that it might represent. We firmly believe that being socially responsible constitutes an essential practice from which all of us can benefit, contributing to life improvement in the community and for environmental sustainability.

Keywords: Corporate social responsibility; Financial performance; Panel data; Portugal; Probit model.

Despite the advances in single-cell transcriptomics, the reconstruction of gene regulatory networks remains challenging. Both the large amount of zero counts in experimental data and the lack of a consensus preprocessing pipeline for single-cell RNA sequencing (scRNA-seq) data make it hard to infer networks. Imputation can be applied in order to enhance gene-gene correlations and facilitate downstream analysis. However, it is unclear what consequences imputation methods have on the reconstruction of gene regulatory networks. To study this, we evaluate the differences on the performance and structure of reconstructed networks before and after imputation in single-cell data. We observe an inflation of gene-gene correlations that affects the predicted network structures and may decrease the performance of network reconstruction in general. However, within the modest limits of achievable results, we also make a recommendation as to an advisable combination of algorithms while warning against the indiscriminate use of imputation before network reconstruction in general.

Keywords: gene regulation; imputation; network inference; network reconstruction; single-cell RNA-seq; single-cell data analysis.

The VUV photoionisation and photofragmentation of cyclo-alanine-alanine (cAA) has been studied in a joint experimental and theoretical work. The photoelectron spectrum and the photoelectron-photoion coincidence (PEPICO) measurements, which enable control of the energy being deposited, combined with quantum chemistry calculations, provide direct insight into the cAA molecular stability after photoionisation. The analysis of the ion-neutral coincidence experiments with the molecular dynamics simulations and the exploration of the potential energy surface allows a complete identification of the fragmentation pathways. It has been found that the fragmentation always starts with the ring opening through the C-C bond cleavage, followed by release of neutral CO or HNCO moieties.

Motivation: The wealth of protein structures collected in the Protein Data Bank enabled large-scale studies of their function and evolution. Such studies, however, require the generation of customized data sets combining the structural data with miscellaneous accessory resources providing functional, taxonomic, and other annotations. Unfortunately, the functionality of currently available tools for the creation of such data sets is limited and their usage frequently requires laborious surveying of various data sources and resolving inconsistencies between their versions.

Results: To address this problem, we developed localpdb, a versatile Python library for the management of protein structures and their annotations. The library features a flexible plugin system enabling seamless unification of the structural data with diverse auxiliary resources, full version control, and powerful functionality of creating highly customized data sets. The localpdb can be used in a wide range of bioinformatic tasks, in particular those involving large-scale protein structural analyses and machine learning.

Availability: localpdb is freely available at https://github.com/labstructbioinf/localpdb. Documentation along with the usage examples can be accessed at https://labstructbioinf.github.io/localpdb/.

Circulating phospholipids have been considered as biomarkers and therapeutic targets in multiple disorders. Atopic dermatitis (AD) is the most common inflammatory skin disease. Although there are numerous studies having addressed stratum corneum lipids in the context of epidermal barrier, little is known about the circulating lipids in patients with AD. In this study, we explored the changes of serum phospholipids in AD using liquid chromatography coupled to tandem mass spectrometry and sought serum lipids' contribution to clinical status. Several serum levels of phospholipids were altered in the AD group (n = 179) compared with that in healthy controls (n = 47) and patients without AD with atopic comorbidities (n = 22); lipids exhibiting the apparent changes included increased sphingosine, multiple variants of phosphatidylcholine, and decreased ceramide (16:0) in patients with AD. Moreover, serum levels of sphingosine correlated with the severity of AD, and sphingosine and ceramide(16:0) were also detected as the risk-increasing effect and risk-reduction effect of AD, respectively. In summary, alterations in the serum concentration of phospholipids are seen in patients with AD. Although more detailed investigations will be needed to evaluate the significance of the changes in circulating lipids in AD, these findings can provide, to our knowledge, previously unreported insight into AD's pathogenesis and therapeutic strategies.

Keywords: AD, atopic dermatitis; Cer, ceramide; EASI, eczema area and severity index; LPC, lysophosphatidylcholine; LPE, lysophosphatidylethanolamine; PC, phosphatidylcholine; S1P, sphingosine-1-phosphate; Sph, sphingosine.

Francis Crick advanced two distinct but interrelated fundamental principles of molecular biology: (1) the Sequence Hypothesis and (2) the Central Dogma. The Sequence Hypothesis defines biological information transfer as the residue-by-residue transfer of sequence information between nucleic acids and to proteins. This is commonly summarized as DNA ➔ RNA ➔ protein and is colloquially referred to as the Central Dogma. More specifically, however, the Central Dogma expounded by Crick included a critical restriction, stipulating that "once sequential information has passed into protein it cannot get out again." Under this definition, the Central Dogma has stood the test of time despite challenges. In principle, a violation of the Central Dogma could transpire through synthetic biology or by natural occurrence. To address these possibilities, we draw insights from existing modes of information transfer in protein synthesis and from synthetic Clustered Regularly-Interspaced Short Palindromic Repeats (CRISPR) gene-editing. We introduce a three-part evaluation scheme, which we apply to the CRISPR/Cas9 system and the more recent CRISPR prime editing system. Potential mechanisms by which engineered sequence editing systems might violate the Central Dogma are considered. We conclude that although information transfer in protein synthesis and CRISPR gene-editing remain within the bounds of the Central Dogma, the underlying mechanisms point toward an avenue of synthetic biology that could directly violate the Central Dogma. Finally, we speculate on some of the theoretical and practical implications of a protein-derived information transfer system. This article is categorized under: RNA Evolution and Genomics > Ribonomics RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Mechanisms.

Keywords: CRISPR; central dogma; protein synthesis; synthetic biology.

The classical theory of safety-efficiency trade-off is a common theme in plant sciences. Despite safety and efficiency partly compensating for each other physiologically (namely, there is a compensation effect, CE, among traits from the "whole" organism perspective), they are always mathematically described as a trade-off against one another. However, the compensation effect has never been defined and quantified, let alone its role in the xylem water transport and subsequently photosynthesis. Here, we developed an alternative theory to define the CE as a positive relationship between safety and efficiency, and further define a new trade-off index, SETO, that is expressed as CE multiplied by a trade-off factor (differing from the classical average trade-off value). Then, we tested SETO- and CE-photosynthetic rate relationships across different levels based on a common garden experiment using nine conifers and published data for gymnosperms. The results demonstrated that the compensation effect in xylem functions was the dominant force in facilitating photosynthetic rates from species- to phylum-scale. By integrating the compensation effect into the xylem hydraulic functional strategy, our study clearly indicated that the compensation effect is the evolutionary basis for the coordination of xylem hydraulic and photosynthesis physiology.

Objective: To describe a minimally invasive approach to the parathyroid gland for the treatment of primary hyperparathyroidism.

Study design: Surgical technique description and clinical case report.

Animals: Five canine cadavers and 5 client-owned dogs with primary hyperparathyroidism.

Methods: A surgical technique for minimally invasive video-assisted parathyroidectomy (MIVAP), described for humans, was adapted for dogs. With the dog in dorsal recumbency, a 15 mm incision was made on the midline, 1 finger width caudal to the cricoid cartilage of the larynx. A 5 mm 30° rigid endoscope was inserted into the peritracheal space with the aid of a blunt suction dissector, and fine elevators. The parathyroid was subsequently removed using electrocautery and blunt and sharp dissection. The technique was refined in 5 cadaver dogs to assess feasibility, and was subsequently performed in 5 clinical cases.

Results: A minimally invasive approach to the parathyroid gland was possible and allowed successful removal of a parathyroid mass in 5 dogs without complication. The use of fluid ingress was trialed in 1 cadaver and not found to be helpful. The use of a blunt suction dissector greatly facilitated dissection of the peritracheal space.

Conclusion: Minimally invasive video-assisted parathyroidectomy is feasible in dogs and was not associated with complications in 5 clinical cases.

Clinical significance: Minimally invasive techniques tend to reduce morbidity and are popular with pet owners. This study demonstrates that a minimally invasive technique may be considered for parathyroidectomy in dogs.

Motivation: Protein-protein interactions (PPI) play important roles in cellular activities. Due to the technical difficulty and high cost of experimental methods, there are considerable interests towards the development of computational approaches, such as protein docking, to decipher PPI patterns. One of the important and difficult aspects in protein docking is recognizing near-native conformations from a set of decoys, but unfortunately traditional scoring functions still suffer from limited accuracy. Therefore, new scoring methods are pressingly needed in methodological and/or practical implications.

Results: We present a new deep learning-based scoring method for ranking protein-protein docking models based on a three-dimensional (3D) RepVGG network, named TRScore. To recognize near-native conformations from a set of decoys, TRScore voxelizes the protein-protein interface into a 3D grid labeled by the number of atoms in different physicochemical classes. Benefiting from the deep convolutional RepVGG architecture, TRScore can effectively capture the subtle differences between energetically favorable near-native models and unfavorable non-native decoys without needing extra information. TRScore was extensively evaluated on diverse test sets including protein-protein docking benchmark 5.0 update set, DockGround decoy set, as well as realistic CAPRI decoy set, and overall obtained a significant improvement over existing methods in cross validation and independent evaluations.

Availability: Codes available at: https://github.com/BioinformaticsCSU/TRScore.

Motivation: RNA sequencing and other high-throughput technologies are essential in understanding complex diseases, such as cancers, but are susceptible to technical factors manifesting as patterns in the measurements. These batch patterns hinder the discovery of biologically relevant patterns. Unbiased batch effect correction in heterogeneous populations currently requires special experimental designs or phenotypic labels, which are not readily available for patient samples in existing datasets.

Results: We present POIBM, an RNA-seq batch correction method, which learns virtual reference samples directly from the data. We use a breast cancer cell line dataset to show that POIBM exceeds or matches the performance of previous methods, while being blind to the phenotypes. Further, we analyze The Cancer Genome Atlas RNA-seq data to show that batch effects plague many cancer types; POIBM effectively discovers the true replicates in stomach adenocarcinoma; and integrating the corrected data in endometrial carcinoma improves cancer subtyping.

Availability: https://bitbucket.org/anthakki/poibm/ (archived at https://doi.org/10.5281/zenodo.6122436).

Bovine milk is rich in extracellular vesicles (mEVs) which have been suggested as a possible drug delivery vehicle with oral bioavailability. As the digestive fluids contain many lipid- and protein-degrading enzymes, we explored whether mEVs given sublingually could be taken up systemically. mEVs were isolated using three different protocols, which were 120 nm in diameter and carried bovine CD81. Fluorescently stained mEVs given by sublingual route were detected in the circulation, whereas mEVs given by gavage were detected at 2-Log lower concentrations. As proof of the concept, we loaded mEVs with the antidiabetic drug Liraglutide (LRT-EV), which reduced blood glucose levels when given by the sublingual route but showed no efficacy via gavaging. This study suggests that mEV may be an efficient delivery vehicle for drugs that are not orally bioavailable, and LRT-loaded EVs have the potential as the next-generation drug delivery platform for the treatment of chronic diseases, including diabetes.

Keywords: Nanomedicine; Pharmacokinetics; drug delivery; exosome; extracellular vesicle.

Chlormethine is a bifunctional cytotoxic alkylating agent that binds to DNA, resulting in cell death (apoptosis). Chlormethine (also known as mechlorethamine) gel (CL gel) was approved in the European Union in 2017 and was first used in 2019. The aim of the study is to examine evidence regarding the efficacy and safety of chlormethine gel in everyday clinical experience from a cutaneous lymphoma centre. Twenty-three patients with stage IA-IIB mycosis fungoides received chlormethine gel between September 2020 and May 2021. All patients started by applying the gel daily and were monitored every month. At 1, 3, 6 and 9 months, 0%, 43.47%, 56.52% and 65.22% of patients, respectively, achieved an overall response. Five out of 23 patients (21.73%) achieved near complete response at a mean time of 6 months. Chlormethine gel was given as monotherapy in 12 patients (52.17%), and in addition to systemic treatments (methotrexate and peginterferon alpha-2a) in 11 patients (47.82%). Adverse events (AE) were recorded in 43.47% of patients, but only 3 discontinued treatment, due to dermatitis. Scale down of the treatment to application 3-times per week led to better patient compliance. This study shows that chlormethine gel is effective and safe in patients with mycosis fungoides with different types of skin lesions.

Methods that increase sensitivity are a constant topic in research. To increase the sensitivity for high-performance liquid chromatography (HPLC) a continuous injection method with a sinusoidal analyte concentration profile was developed. The sinusoidal analyte concentration profile is obtained by a sinusoidal variation of the relative volume contents between two solvent reservoirs, one containing a pure solvent and the other an analyte stock solution prepared with the same solvent. Discrete Fourier transformation enables the analyte-specific phase angle shift to be calculated from the chromatograms. The proposed method is established and evaluated for size exclusion chromatography (SEC). Accordingly, the phase angle shift is used for molecular weight determination by establishing a molecular weight calibration using different narrowly distributed polystyrene (PS) calibration standards. In a comparison with conventional SEC, the Signal-to-Noise ratio (S/N), normalized to the square root of the time of the evaluated data set, increases by a factor of approximately 50.

Objective: Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency, characterized by micro-thrombocytopenia, recurrent infections, and eczema. This study aims to describe common oral manifestations and evaluate oral microbioma of WAS patients.

Material and methods: In this cohort study, 11 male WAS patients and 16 male healthy controls were evaluated in our Center between 2010 and 2018. Data about clinical history, oral examination, Gingival Index (GI) and Plaque Index (PI) were collected from both groups. Periodontal microbiological flora was evaluated on samples of the gingival sulcus.

Results: WAS subjects presented with premature loss of deciduous and permanent teeth, inclusions, eruption disturbance, and significantly worse GI and PI. They also showed a trend toward a higher total bacterial load. Fusobacterium nucleatum, reported to contribute to periodontitis onset, was the most prevalent bacteria, together with Porphyromonas gingivalis and Tannerella forsythia.

Conclusions: Our data suggest that WAS patients are at greater risk of alterations in the oral cavity. The statistically higher incidence of periodontitis and the trend to higher prevalence of potentially pathological bacterial species in our small cohort, that should be confirmed in future in a larger population, underline the importance of dentistry monitoring as part of the multidisciplinary management of WAS patients.

Keywords: Wiskott-Aldrich syndrome; microbiota; periodontitis; primary immunodeficiencies.

Successful social communication is complex; it relies on effectively deploying and continuously revising one's behavior to fit the needs of a given conversation, partner, and context. For example, a skilled conversationalist may instinctively become less talkative with a quiet partner and more talkative with a chattier one. Prior research suggests that behavioral flexibility across social contexts can be a particular challenge for individuals with autism spectrum condition (ASC), and that difficulty adapting to the changing needs of a conversation contributes to communicative breakdowns and poor social outcomes. In this study, we examine whether reduced conversational adaptation, as measured by talkativeness, differentiates 48 verbally fluent children and teens with ASC from 50 neurotypical (NT) peers matched on age, intelligence quotient, and sex ratio. Participants completed the Contextual Assessment of Social Skills with two novel conversation partners. The first acted interested in the conversation and talked more (Interested condition), while the second acted bored and talked less (Bored condition). Results revealed that NT participants emulated their conversation partner's behavior by being more talkative in the Interested condition as compared to the Bored condition (z = 9.92, p < 0.001). In contrast, the ASC group did not differentially adapt their behavior to the Bored versus Interested context, instead remaining consistently talkative in both (p = 0.88). The results of this study have implications for understanding social communication and behavioral adaptation in ASC, and may be valuable for clinicians interested in improving conversational competence in verbally fluent individuals with autism. LAY SUMMARY: Social communication-including everyday conversations-can be challenging for individuals on the autism spectrum. In successful conversations, people tend to adjust aspects of their language to be more similar to their partners'. In this study, we found that children and teens with autism did not change their own talkativeness in response to a social partner who was more or less talkative, whereas neurotypical peers did. These findings have clinical implications for improving conversational competence in verbally fluent individuals with autism.

Keywords: autism spectrum condition; autism spectrum disorder; conversational adaptation; language; social behavior; social communication.

The effects of inflammatory responses and polymorphisms of the genes encoding cytochrome P450 (CYP) (CYP2C19 and CYP3A5), flavin-containing monooxygenase 3 (FMO3), pregnane X receptor (NR1I2), constitutive androstane receptor (NR1I3), and CYP oxidoreductase (POR) on the ratio of voriconazole (VRCZ) N-oxide to VRCZ (VNO/VRCZ) and steady-state trough concentrations (C_0h ) of VRCZ were investigated. A total of 56 blood samples were collected from 36 Japanese patients. Results of multiple linear regression analyses demonstrated that the presence of the extensive metabolizer CYP2C19 genotype, the dose per administration, and the presence of the NR1I2 rs3814057 C/C genotype were independent factors influencing the VNO/VRCZ ratio in patients with CRP levels of less than 40 mg/L (standardized regression coefficients (SRC) = 0.448, -0.301, and 0.390, respectively; all p < .05). With regard to the concentration of VRCZ itself, in addition to the above factors, the presence of the NR1I2 rs7643645 G/G and rs3814055 T/T genotypes were found to be independent factors influencing the VRCZ C_0h in these patients (SRC = -0.430, 0.424, -0.326, 0.406 and -0.455, respectively; all p < .05). On the contrary, in patients with CRP levels of at least 40 mg/L, no independent factors were found to affect VNO/VRCZ and VRCZ C_0h . Inflammatory responses, and CYP2C19 and NR1I2 polymorphisms may be useful information for the individualization of VRCZ dosages.

Keywords: CRP; CYP2C19; NR1I2 polymorphism; voriconazole; voriconazole N-oxide.

Lathyrus sativus, commonly known as grass pea, is a nutrient-rich pulse crop with remarkable climate-resilient attributes. However, wide use of this nutritious crop is not adopted owing to the presence of a non-protein amino acid β-N-oxalyl-l-α,β-diaminopropionic acid (β-ODAP), which is neurotoxic if consumed in large quantities. We conducted a de novo transcriptomic profiling of two ODAP contrasting cultivars, Pusa-24 and its somaclonal variant Ratan, to understand the genetic changes leading to and associated with β-ODAP levels. Differential gene expression analysis showed that a variety of genes are downregulated in low β-ODAP cultivar Ratan and include genes involved in biotic/abiotic stress tolerance, redox metabolism, hormonal metabolism, and sucrose, and starch metabolism. Several genes related to chromatin remodeling are differentially expressed in cultivar Ratan. β-ODAP biosynthetic genes in these cultivars showed differential upregulation upon stress. ODAP content of these cultivars varied differentially upon stress and development. Physiological experiments indicate reduced relative water content and perturbed abscisic acid levels in the low ODAP cultivar. Altogether, our results suggest that the low ODAP cultivar may have a reduced stress tolerance. The dataset provides insight into the biological role of ODAP and will be helpful for hypothesis-driven experiments to understand ODAP biosynthesis and regulation.

Introduction: Medical assistance in dying (MAiD) was legalized in Canada in 2016. Cancer accounts for 60% to 65% of MAiD cases. Lung cancer, the most common cause of cancer death, is expected to makeup a large number of MAiD cases. Lung cancer treatment has advanced in recent years; however, involvement of oncology specialists and use of systemic therapy in patients who receive MAiD are unknown.

Methods: All patients with lung cancer referred to the Champlain Regional MAiD Program from June 17, 2016, to November 30, 2020, were reviewed. Baseline demographics, diagnostic, referral, and treatment details were collected by retrospective review. Coprimary end points were the proportion of patients who met a medical oncologist or who received systemic therapy.

Results: During the study period, 255 patients with cancer underwent MAiD. Of these, 45 (17.6%) had lung cancer, comprising our final study population. Baseline characteristics: median age 72 years, 64% female, 85% former or current smoking history, 82% non-small cell, 4% small cell, and 13% clinical diagnosis without biopsy. Most patients (78%) were seen by a medical oncologist, though only 16 (36%) received systemic therapy for advanced disease. In subpopulations of interest, 45% of patients with programmed death-ligand 1 greater than or equal to 50% received immunotherapy and 75% with an oncogenic driver mutation received targeted therapy. There were 26 patients (58%) who had a documented discussion with their oncologist regarding the transition to best supportive care.

Conclusions: Most patients with lung cancer are assessed by an oncology specialist before MAiD, though less than half received systemic therapy. Among patients with more treatable forms of lung cancer, many patients still undergo MAiD without accessing, or in some cases being assessed for, these treatment options.

Keywords: Assisted suicide; Canada; End of life care; Lung cancer.

Introduction: During a health crisis, hospitals must prioritize activities and resources, which can compromise clerkship-based learning. We explored how health crises affect clinical clerkships using the COVID-19 pandemic as an example.

Methods: In a constructivist qualitative study, we conducted 22 semi-structured interviews with key stakeholders (i.e., medical students and doctors) from two teaching hospitals and ten different departments. We used thematic analysis to investigate our data and used stakeholder theory as a sensitising concept.

Results: We identified three themes: (1) emotional triggers and reactions; (2) negotiation of legitimacy; and (3) building resilience. Our results suggest that the health crisis accentuated already existing problems in clerkships, such as students' feelings of low legitimacy, constant negotiation of roles, inconsistencies navigating rules and regulations, and low levels of active participation. Medical students and doctors adapted to the new organizational demands by developing increased resilience. Students responded by reaching out for guidance and acceptance to remain relevant in the clinical clerkships. Doctors developed a behaviour of closing in and focused on managing themselves and their patients. This created tension between these two stakeholder groups.

Conclusion: A health crisis can critically disrupt the hierarchical structure within the clinical clerkships and exacerbate existing conflicts between stakeholder groups. When medical students are not perceived as legitimate stakeholders in clinical clerkships during a health crisis, their attendance is perceived as unnecessary or even a nuisance. Despite increased student proactiveness and resilience, their roles inevitably shift from being doctors-to-be to students-to-be-managed.