A nasal cell atlas reveals heterogeneity of tuft cells and their role in directing olfactory stem cell proliferation.

The olfactory neuroepithelium serves as a sensory organ for odors and forms part of the nasal mucosal barrier. Olfactory sensory neurons are surrounded and supported by epithelial cells. Among them, microvillous cells (MVCs) are strategically positioned at the apical surface, but their specific functions are enigmatic, and their relationship to the other specialized epithelial cells is unclear. Here, we establish that the family of MVCs comprises tuft cells and ionocytes in both mice and humans. Integrating analysis of the respiratory and olfactory epithelia, we define the distinct receptor expression of TRPM5+ tuft-MVCs compared with Gɑ-gustducinhigh respiratory tuft cells and characterize a previously undescribed population of glandular DCLK1+ tuft cells. To establish how allergen sensing by tuft-MVCs might direct olfactory mucosal responses, we used an integrated single-cell transcriptional and protein analysis. Inhalation of Alternaria induced mucosal epithelial effector molecules including Chil4 and a distinct pathway leading to proliferation of the quiescent olfactory horizontal basal stem cell (HBC) pool, both triggered in the absence of olfactory apoptosis. Alternaria- and ATP-elicited HBC proliferation was dependent on TRPM5+ tuft-MVCs, identifying these specialized epithelial cells as regulators of olfactory stem cell responses. Together, our data provide high-resolution characterization of nasal tuft cell heterogeneity and identify a function of TRPM5+ tuft-MVCs in directing the olfactory mucosal response to allergens.

Self-Employed Canadians' Experiences with Cancer and Work: A Qualitative Study.

Self-employed individuals with cancer face unique challenges that have not been fully explored in previous research. For example, while some studies conducted in Europe have suggested that self-employed workers with cancer experience more adverse health and work-related outcomes compared to salaried workers, the specific manners in which cancer affects the health, work, and businesses of self-employed individuals remain inadequately understood. This lack of understanding represents a crucial gap in the literature, as self-employed individuals make up a significant portion of the workforce in many countries, including Canada. To address this gap, a qualitative interpretive description study was undertaken to explore the experiences of 23 self-employed Canadians diagnosed with cancer from six provinces, with the aim of generating insights into the unique challenges faced by this population. The interviews were conducted in the language chosen by the participants from the two official languages of Canada, namely English and French. Using reflexive thematic analysis, four major themes and twelve subthemes were generated from the participants' shared accounts that reflected the impact of cancer on self-employed Canadians' physical, cognitive, and psychological function, affecting their work ability and their ability to maintain their business and financial well-being. Participants in the study also shared strategies they used to continue working and maintain their business during their cancer experience. This study sheds light on the impact of cancer on self-employed individuals and provides insight into the experiences of self-employed individuals with cancer that can inform the development of interventions to support this population.

Novel Multidisciplinary Vascular Access Team Helps to Improve ICU Workflow Amidst Covid-19 Pandemic.

OBJECTIVE: The surge in critically ill patients has pressured hospitals to expand their intensive care unit capacities and critical care staff. This was difficult given the country's shortage of intensivists. This paper describes the implementation of a multidisciplinary central line placement team and its impact in reducing the vascular access workload of ICU physicians during the height of the COVID-19 pandemic. METHODS: Vascular surgeons, interventionalists, and anesthesiologists, were redeployed to the ICU Access team to place central and arterial lines. Nurses with expertise in vascular access were recruited to the team to streamline consultation and assist with line placement. RESULTS: While 51 central and arterial lines were placed per 100 ICU patients in 2019, there were 87 central and arterial lines placed per 100 COVID-19 ICU patients in the sole month of April, 2020. The ICU Access Team placed 107 of the 226 vascular access devices in April 2020, reducing the procedure-related workload of ICU treating teams by 46%. CONCLUSIONS: The ICU Access Team was able to complete a large proportion of vascular access insertions without reported complications. Given another mass casualty event, this ICU Access Team could be reassembled to rapidly meet the increased vascular access needs of patients.

Tuft cell-produced cysteinyl leukotrienes and IL-25 synergistically initiate lung type 2 inflammation.

Aeroallergen sensing by airway epithelial cells triggers pathogenic immune responses leading to type 2 inflammation, the hallmark of chronic airway diseases such as asthma. Tuft cells are rare epithelial cells and the dominant source of interleukin-25 (IL-25), an epithelial cytokine, and cysteinyl leukotrienes (CysLTs), lipid mediators of vascular permeability and chemotaxis. How these two mediators derived from the same cell might cooperatively promote type 2 inflammation in the airways has not been clarified. Here, we showed that inhalation of the parent leukotriene C4 (LTC4) in combination with a subthreshold dose of IL-25 led to activation of two innate immune cells: inflammatory type 2 innate lymphoid cell (ILC2) for proliferation and cytokine production, and dendritic cells (DCs). This cooperative effect led to a much greater recruitment of eosinophils and CD4+ T cell expansion indicative of synergy. Whereas lung eosinophilia was dominantly mediated through the classical CysLT receptor CysLT1R, type 2 cytokines and activation of innate immune cells required signaling through CysLT1R and partially CysLT2R. Tuft cell­specific deletion of Ltc4s, the terminal enzyme required for CysLT production, reduced lung inflammation and the systemic immune response after inhalation of the mold aeroallergen Alternaria; this effect was further enhanced by concomitant blockade of IL-25. Our findings identified a potent synergy of CysLTs and IL-25 downstream of aeroallergen-trigged activation of airway tuft cells leading to a highly polarized type 2 immune response and further implicate airway tuft cells as powerful modulators of type 2 immunity in the lungs.

LATERAL ORGAN BOUNDARIES DOMAIN 25 functions as a key regulator of haustorium development in dodders.

Parasitic plants reduce crop yield worldwide. Dodder (Cuscuta campestris) is a stem parasite that attaches to its host, using haustoria to extract nutrients and water. We analyzed the transcriptome of six C. campestris tissues and identified a key gene, LATERAL ORGAN BOUNDARIES DOMAIN 25 (CcLBD25), as highly expressed in prehaustoria and haustoria. Gene coexpression networks from different tissue types and laser-capture microdissection RNA-sequencing data indicated that CcLBD25 could be essential for regulating cell wall loosening and organogenesis. We employed host-induced gene silencing by generating transgenic tomato (Solanum lycopersicum) hosts that express hairpin RNAs to target and down-regulate CcLBD25 in the parasite. Our results showed that C. campestris growing on CcLBD25 RNAi transgenic tomatoes transited to the flowering stage earlier and had reduced biomass compared with C. campestris growing on wild-type (WT) hosts, suggesting that parasites growing on transgenic plants were stressed due to insufficient nutrient acquisition. We developed an in vitro haustorium system to assay the number of prehaustoria produced on strands from C. campestris. Cuscuta campestris grown on CcLBD25 RNAi tomatoes produced fewer prehaustoria than those grown on WT tomatoes, indicating that down-regulating CcLBD25 may affect haustorium initiation. Cuscuta campestris haustoria growing on CcLBD25 RNAi tomatoes exhibited reduced pectin digestion and lacked searching hyphae, which interfered with haustorium penetration and formation of vascular connections. The results of this study elucidate the role of CcLBD25 in haustorium development and might contribute to developing parasite-resistant crops.

Limb Laterality Recognition Score: A Reliable Clinical Measure Related to Phantom Limb Pain.

Objective: To explore the usefulness of the limb laterality recognition score as a clinical measure of phantom limb pain, regarding test-retest reliability and association of limb laterality recognition scores with phantom limb pain measures. Design: Retrospective cohort. Setting: Community support group. Subjects: Eleven adults who averaged 4.8 years since lower limb amputation due to vascular pathologies (N = 9), trauma (N = 1), and cancer (N = 1). Methods: Subjects self-reported amputated limb pain using the sensation subsection of the Prosthetic Evaluation Questionnaire and back and sound limb pain. Using numbered iPads that corresponded to the self-reports, subjects played the Recognise Foot game to assess limb laterality recognition ability. Subjects identified the laterality of 20 foot images, within two seconds each. The software collected accuracy and speed scores in basic, vanilla, and context conditions for two rounds in random order. Basic showed feet against black backgrounds, vanilla showed feet with various monochromatic backgrounds, and context showed feet in clothed or environmental contexts. So that greater accuracy in less time meant a better score, accuracy scores were divided by completion speed. Intraclass correlation coefficient (ICC)3,1 assessed test-retest reliability. Correlations between accuracy/speed and phantom limb pain measures were assessed with Spearman's rho (categorical) and Pearson coefficients (continuous). Results: Accuracy/speed test-retest reliability was strong (ICC = 0.72) and inversely associated with phantom limb pain frequency (context rho = 0.72). Conclusions: Limb laterality recognition accuracy/speed in the context condition had good test-retest reliability and correlated strongly with phantom limb pain frequency. Accuracy/speed limb laterality recognition ability relates to phantom limb pain and may be a valid clinical or research measure.