Systemic Factors Affecting Prognosis and Outcomes in Periodontal Disease.

This review delves into the effects of autoimmune conditions like rheumatoid arthritis, inflammatory disorders such as irritable bowel syndrome, cardiovascular disease, diabetes, infectious ailments like human immunodeficiency virus, and their medications on periodontal therapy outcomes. It also explores the influence of hormones. Understanding these systemic factors is crucial for optimizing periodontal health and treatment efficacy. The review underscores the necessity of considering these variables in periodontal care. Other vital systemic factors are addressed elsewhere in this special edition.

Characterization of FGF21 Sites of Production and Signaling in Mice.

Fibroblast growth factor (FGF) 21 is an endocrine hormone that signals to multiple tissues to regulate metabolism. FGF21 and another endocrine FGF, FGF15/19, signal to target tissues by binding to the co-receptor ß-klotho (KLB), which then facilitates the interaction of these different FGFs with their preferred FGF receptor. KLB is expressed in multiple metabolic tissues, but the specific cell types and spatial distribution of these cells are not known. Furthermore, while circulating FGF21 is primarily produced by the liver, recent publications have indicated that brain-derived FGF21 impacts memory and learning. Here we use reporter mice to comprehensively assess KLB and FGF21 expression throughout the body. These data provide an important resource for guiding future studies to identify important peripheral and central targets of FGFs and to determine the significance of nonhepatic FGF21 production.

"All you need is compassion?" a latent profile analysis of neglect and self-compassion on child mental health.

BACKGROUND: Neglect is a common form of child maltreatment and profoundly affects children's mental health globally. Self-compassion may help children cope with neglect but the role of self-compassion in neglect context has been understudied. This study identifies distinct patterns of self-compassion and child neglect and explores how neglect and self-compassion profiles correlate with child mental health. METHODS: The sample includes 3342 children aged 8-16 (49.6 % female) from a national survey of 29 provinces in China using a multistage sampling method. We used latent profile analysis to identify distinct profiles of self-compassion and neglect and examine their combined effects on child mental health, including both positive indicators (hope, resilience) and negative indicators (anxiety, depression, academic burnout, and peer problems). RESULTS: We identified four neglect/self-compassion profiles: Adaptable Self-Carers (average neglect/high self-compassion), Vulnerable Languishers (high neglect/low self-compassion), Stable Self-Soothers (low neglect/average self-compassion), and Opportune Thrivers (low neglect/high self-compassion). The Vulnerable Languishers group exhibited the poorest mental health outcomes, whereas the Opportune Thrivers showed the best outcomes. Adaptable Self-Carers, although experiencing more neglect than Stable Self-Soothers, had better mental health than the latter, possibly due to their greater self-compassion. LIMITATIONS: The cross-sectional design limits our ability to determine causality, and the use of self-reported measures increases response bias risk. CONCLUSIONS: More self-compassion and less neglect are associated with more positive mental health outcomes. Moreover, self-compassion is a potential protective factor against the adverse effects of neglect on child mental health. Fostering self-compassion may boost positive adjustment in children who have experienced neglect.

Microfluidics produced ATRA-loaded PLGA NPs reduced tuberculosis burden in alveolar epithelial cells and enabled high delivered dose under simulated human breathing pattern in 3D printed head models.

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), is second only to COVID-19 as the top infectious disease killer worldwide. Multi-drug resistant TB (MDR-TB) may arise because of poor patient adherence to medications due to lengthy treatment duration and side effects. Delivering novel host directed therapies (HDT), like all trans retinoic acid (ATRA) may help to improve drug regimens and reduce the incidence of MDR-TB. Local delivery of ATRA to the site of infection leads to higher bioavailability and reduced systemic side effects. ATRA is poorly soluble in water and has a short half-life in plasma. Therefore, it requires a formulation step before it can be administered in vivo. ATRA loaded PLGA nanoparticles suitable for nebulization were manufactured and optimized using a scalable nanomanufacturing microfluidics (MF) mixing approach (MF-ATRA-PLGA NPs). MF-ATRA-PLGA NPs demonstrated a dose dependent inhibition of Mtb growth in TB-infected A549 alveolar epithelial cell model while preserving cell viability. The MF-ATRA-PLGA NPs were nebulized with the Aerogen Solo vibrating mesh nebulizer, with aerosol droplet size characterized using laser diffraction and the estimated delivered dose was determined. The volume median diameter (VMD) of the MF-ATRA-PLGA NPs was 3.00 ± 0.18 µm. The inhaled dose delivered in adult and paediatric 3D printed head models under a simulated normal adult and paediatric breathing pattern was found to be 47.05 ± 3 % and 20.15 ± 3.46 % respectively. These aerosol characteristics of MF-ATRA-PLGA NPs supports its suitability for delivery to the lungs via inhalation. The data generated on the efficacy of an inhalable, scalable and regulatory friendly ATRA-PLGA NPs formulation provides a foundation on which further pre-clinical testing can be built. Overall, the results of this project are promising for future research into ATRA loaded NPs formulations as inhaled host directed therapies for TB.

Decreasing utilization for postoperative radiation therapy in locoregionally advanced medullary thyroid cancer.

BACKGROUND: Use of postoperative radiation therapy (PORT) in locoregionally advanced medullary thyroid cancer (MTC) remains controversial. The objective was to evaluate the effect of PORT on locoregional control (LRC) and overall survival (OS). METHODS: Retrospective cohort study of 346 MTC patients separated into PORT and no-PORT cohorts. Relative indications for PORT, as well as changes in patterns of treatment, were recorded. RESULTS: 49/346 (14%) received PORT. PORT was associated with worse OS; adjusted HR = 2.0 (95%CI 1.3-3.3). PORT was not associated with improved LRC, even when adjusting for advanced stage (Stage III p = 0.892; Stage IV p = 0.101). PORT and targeted therapy were not associated with improved OS compared to targeted therapy alone; adjusted HR = 1.2 (95%CI 0.3-4.1). CONCLUSIONS: Use of PORT in MTC has decreased and its indications have become more selective, coinciding with the advent of effective targeted therapies. Overall, PORT was not associated with improved LRC or OS.

Rapid, tunable, and multiplexed detection of RNA using convective array PCR.

Detection of RNA targets is typically achieved through RT-qPCR or RNAseq. RT-qPCR is rapid but limited in number and complexity of targets detected, while RNAseq is high-throughput but takes multiple days. We demonstrate simultaneous amplification and detection of 28 distinct RNA targets from a single unsplit purified RNA sample in under 40 minutes using our convective array PCR (caPCR) technology. We integrate tunable strand displacement probes into caPCR to allow detection of RNA species with programmable sequence selectivity for either a single, perfectly matched target sequence or for targets with up to 2 single-nucleotide variants within the probe-binding regions. Tunable probes allow for robust detection of desired RNA species against high homology background sequences and robust detection of RNA species with significant sequence diversity due to community-acquired mutations. As a proof-of-concept, we experimentally demonstrated detection of 7 human coronaviruses and 7 key variants of concern of SARS-CoV-2 in a single assay.

Comparison of satisfaction with penile prosthesis implantation in patients with prostate cancer radiation therapy versus radical prostatectomy.

Background: Penile prosthesis surgery (PPS) is a commonly used treatment for erectile dysfunction (ED), either as first-line therapy or in cases refractory to other treatment options. In patients with a urologic malignancy such as prostate cancer, surgical interventions like radical prostatectomy (RP) as well as non-surgical treatments such as radiation therapy can all induce ED. PPS as a treatment for ED has high satisfaction rates in the general population. Our aim was to compare sexual satisfaction in patients with prosthesis implantation for ED following RP versus ED following radiation therapy for prostate cancer. Methods: A retrospective chart review from our institutional database was conducted to identify patients who underwent PPS at our institution from 2011 to 2021. Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaire data at least 6 months from implant operative date available was required for inclusion. Eligible patients were placed in one of two groups depending on etiology of ED-following RP or prostate cancer radiation therapy. To prevent crossover confounding; patients with history of pelvic radiation were excluded from the RP group and patients with history of RP were excluded from the radiation group. Data were obtained from 51 patients in the RP group and 32 patients in the radiation therapy group. Mean EDITS scores and additional survey questions were compared between the radiation and RP groups. Results: There was a significant difference in mean survey responses for 8 of the 11 questions in the EDITS questionnaire between the RP group and the radiation group. Additional survey questions administered also found RP patients reported significantly higher rate of satisfaction with size of penis post-operatively versus the radiation group. Conclusions: These preliminary findings, while requiring large-scale follow-up, suggest that there is greater sexual satisfaction and penile prosthesis device satisfaction in patients undergoing IPP placement following RP versus radiation therapy for prostate cancer. Use of validated questionnaires should continue to be utilized in quantifying device and sexual satisfaction following PPS.

Pericardial Fluid Analysis in Diagnosis and Prognosis of Patients Who Underwent Pericardiocentesis.

In this study, we aimed to examine the diagnostic yield of pericardial fluid biochemistry and cytology and their prognostic significance in patients with percutaneously drained pericardial effusions, with and without malignancy. This is a single-center, retrospective study of patients who underwent pericardiocentesis between 2010 and 2020. Data were extracted from electronic patient records, including procedural information, underlying diagnosis, and laboratory results. Patients were grouped into those with and without underlying malignancy. A Cox proportional hazards model was used to analyze the association of variables with mortality. The study included 179 patients; 50% had an underlying malignancy. There were no significant differences in pericardial fluid protein and lactate dehydrogenase between the 2 groups. Diagnostic yield from pericardial fluid analysis was greater in the malignant group (32% vs 11%, p = 0.002); 72% of newly diagnosed malignancies had positive fluid cytology. The 1-year survival was 86% and 33% in nonmalignant and malignant groups, respectively (p <0.001). Of 17 patients who died within the nonmalignant group, idiopathic effusions were the largest group (n = 6). In malignancy, lower pericardial fluid protein and higher serum C-reactive protein were associated with increased risk of mortality. In conclusion, pericardial fluid biochemistry has limited value in determining the etiology of pericardial effusions; fluid cytology is the most important diagnostic test. Mortality in malignant pericardial effusions may be associated with lower pericardial fluid protein levels and a higher serum C-reactive protein. Nonmalignant pericardial effusions do not have a benign prognosis and close follow-up is required.

Effect of nebuliser and patient interface type on fugitive medical aerosol emissions in adult and paediatric patients.

BACKGROUND: Open circuit aerosol therapy is associated with the potential for fugitive emissions of medical aerosol. Various nebulisers and interfaces are used in respiratory treatments, including the recent consideration of filtered interfaces. This study aims to quantify fugitive medical aerosols from various nebuliser types, in conjunction with different filtered and non-filtered interfaces. METHODS: For both simulated adult and paediatric breathing, four nebuliser types were assessed including; a small volume jet nebuliser (SVN), a breath enhanced jet nebuliser (BEN), a breath actuated jet nebuliser (BAN) and a vibrating mesh nebuliser (VMN). A combination of different interfaces were used including filtered and unfiltered mouthpieces, as well as open, valved and filtered facemasks. Aerosol mass concentrations were measured using an Aerodynamic Particle Sizer at 0.8 m and 2.0 m. Additionally, inhaled dose was assessed. RESULTS: Highest mass concentrations recorded were 214 (177, 262) µg m-3 at 0.8 m over 45-minute run. The highest and lowest fugitive emissions were observed for the adult SVN facemask combination, and the adult BAN filtered mouthpiece combination respectively. Fugitive emissions decreased when using breath-actuated (BA) mode compared to continuous (CN) mode on the BAN for the adult and paediatric mouthpiece combination. Lower fugitive emissions were observed when a filtered facemask or mouthpiece was used, compared to unfiltered scenarios. For the simulated adult, highest and lowest inhaled dose were 45.1 (42.6, 45.6)% and 11.0 (10.1,11.9)% for the VMN and SVN respectively. For the simulated paediatric, highest and lowest inhaled dose were 44.0 (42.4, 44.8)% and 6.1 (5.9, 7.0)% for the VMN and BAN CN respectively. Potential inhalation exposure of albuterol was calculated to be up to 0.11 µg and 0.12 µg for a bystander and healthcare worker respectively. CONCLUSION: This work demonstrates the need for filtered interfaces in clinical and homecare settings to minimise fugitive emissions and to reduce the risk of secondary exposure to care givers.

Fibroblast growth factor-21 is required for weight loss induced by the glucagon-like peptide-1 receptor agonist liraglutide in male mice fed high carbohydrate diets.

OBJECTIVE: Glucagon-like peptide-1 receptor (GLP-1R) agonists (GLP-1RA) and fibroblast growth factor-21 (FGF21) confer similar metabolic benefits. GLP-1RA induce FGF21, leading us to investigate mechanisms engaged by the GLP-1RA liraglutide to increase FGF21 levels and the metabolic relevance of liraglutide-induced FGF21. METHODS: Circulating FGF21 levels were measured in fasted male C57BL/6J, neuronal GLP-1R knockout, ß-cell GLP-1R knockout, and liver peroxisome proliferator-activated receptor alpha knockout mice treated acutely with liraglutide. To test the metabolic relevance of liver FGF21 in response to liraglutide, chow-fed control and liver Fgf21 knockout (LivFgf21-/-) mice were treated with vehicle or liraglutide in metabolic chambers. Body weight and composition, food intake, and energy expenditure were measured. Since FGF21 reduces carbohydrate intake, we measured body weight in mice fed matched diets with low- (LC) or high-carbohydrate (HC) content and in mice fed a high-fat, high-sugar (HFHS) diet. This was done in control and LivFgf21-/- mice and in mice lacking neuronal ß-klotho (Klb) expression to disrupt brain FGF21 signaling. RESULTS: Liraglutide increases FGF21 levels independently of decreased food intake via neuronal GLP-1R activation. Lack of liver Fgf21 expression confers resistance to liraglutide-induced weight loss due to attenuated reduction of food intake in chow-fed mice. Liraglutide-induced weight loss was impaired in LivFgf21-/- mice when fed HC and HFHS diets but not when fed a LC diet. Loss of neuronal Klb also attenuated liraglutide-induced weight loss in mice fed HC or HFHS diets. CONCLUSIONS: Our findings support a novel role for a GLP-1R-FGF21 axis in regulating body weight in a dietary carbohydrate-dependent manner.

Liver Fibroblast Growth Factor 21 (FGF21) is Required for the Full Anorectic Effect of the Glucagon-Like Peptide-1 Receptor Agonist Liraglutide in Male Mice fed High Carbohydrate Diets.

Glucagon-like peptide-1 receptor (GLP-1R) agonists and fibroblast growth factor 21 (FGF21) confer similar metabolic benefits. Studies report that GLP-1RA induce FGF21. Here, we investigated the mechanisms engaged by the GLP-1R agonist liraglutide to increase FGF21 levels and the metabolic relevance of liraglutide-induced FGF21. We show that liraglutide increases FGF21 levels via neuronal GLP-1R activation. We also demonstrate that lack of liver Fgf21 expression confers partial resistance to liraglutide-induced weight loss. Since FGF21 reduces carbohydrate intake, we tested whether the contribution of FGF21 to liraglutide-induced weight loss is dependent on dietary carbohydrate content. In control and liver Fgf21 knockout (Liv Fgf21 -/- ) mice fed calorically matched diets with low- (LC) or high-carbohydrate (HC) content, we found that only HC-fed Liv Fgf21 -/- mice were resistant to liraglutide-induced weight loss. Similarly, liraglutide-induced weight loss was partially impaired in Liv Fgf21 -/- mice fed a high-fat, high-sugar (HFHS) diet. Lastly, we show that loss of neuronal ß-klotho expression also diminishes liraglutide-induced weight loss in mice fed a HC or HFHS diet, indicating that FGF21 mediates liraglutide-induced weight loss via neuronal FGF21 action. Our findings support a novel role for a GLP-1R-FGF21 axis in regulating body weight in the presence of high dietary carbohydrate content.

Structure of full-length TSH receptor in complex with antibody K1-70™.

Determination of the full-length thyroid-stimulating hormone receptor (TSHR) structure by cryo-electron microscopy (cryo-EM) is described. The TSHR complexed with human monoclonal TSHR autoantibody K1-70™ (a powerful inhibitor of TSH action) was detergent solubilised, purified to homogeneity and analysed by cryo-EM. The structure (global resolution 3.3 Å) is a monomer with all three domains visible: leucine-rich domain (LRD), hinge region (HR) and transmembrane domain (TMD). The TSHR extracellular domain (ECD, composed of the LRD and HR) is positioned on top of the TMD extracellular surface. Extensive interactions between the TMD and ECD are observed in the structure, and their analysis provides an explanation of the effects of various TSHR mutations on TSHR constitutive activity and on ligand-induced activation. K1-70™ is seen to be well clear of the lipid bilayer. However, superimposition of M22™ (a human monoclonal TSHR autoantibody which is a powerful stimulator of the TSHR) on the cryo-EM structure shows that it would clash with the bilayer unless the TSHR HR rotates upwards as part of the M22™ binding process. This rotation could have an important role in TSHR stimulation by M22™ and as such provides an explanation as to why K1-70™ blocks the binding of TSH and M22™ without activating the receptor itself.

An in vitro study of the effects of respiratory circuit setup and parameters on aerosol delivery during mechanical ventilation.

Introduction: Aerosol therapy is often prescribed concurrently during invasive mechanical ventilation (IMV). This study determines the effects of nebuliser position, circuit humidification source, and most importantly, lung health on the delivery of aerosol in simulated adult and paediatric IMV patients. Furthermore, the influence of closed suction catheters on aerosol delivery is also addressed. Methods: A vibrating mesh nebuliser was used to deliver Albuterol to simulated adult and paediatric IMV patients with differing states of lung health. Four different nebuliser positions and two types of humidification were analysed. Closed suction catheter mounts, a mainstay in IMV therapy, were incorporated into the circuits. The mean ± SD dose of aerosol (%) was assayed from a filter at the distal end of the endotracheal tube. Results: Nebuliser placement and circuit humidification source had no effect on the delivered dose (%) in adults, yet both significantly did in the simulated paediatric patients. The use of closed suction catheter mounts significantly reduced the delivered dose (%) in adults but not in paediatric patients. A simulated healthy lung state generated the largest delivered dose (%), irrespective of nebuliser position in the adult. However, different lung health and nebuliser positions yielded higher delivered doses (%) in paediatrics. Conclusion: Lung health and respiratory circuit composition significantly affect aerosol delivery in both adult and paediatric IMV patients. Nebuliser placement and respiratory circuit humidification source do not affect the delivered dose in adult but do in paediatric IMV patients.

In vitro model for investigating aerosol dispersion in a simulated COVID-19 patient during high-flow nasal cannula treatment.

The use of high-flow nasal cannula in the treatment of COVID-19 infected patients has proven to be a valuable treatment option to improve oxygenation. Early in the pandemic, there were concerns for the degree of risk of disease transmission to health care workers utilizing these treatments that are considered aerosol generating procedures. This study developed an in vitro model to examine the release of simulated patient-derived bioaerosol with and without high-flow nasal cannula at gas flow rates of 30 and 50 L/min. Aerosol dispersion was evaluated at 30 and 90 cm distances. Reduction of transmission risk was assessed using a surgical facemask on the manikin. Results indicated that the use of a facemask facilitated a 94-95% reduction in exhaled aerosol concentration at 30 cm and 22-60% reduction for 90 cm distance across both gas flow rates. This bench study confirms that this in vitro model can be used as a tool to assess the risk of disease transmission during aerosol generating procedures in a simulated patient and to test factors to mitigate the risk.

Two cases of tularemia in hunters from rural Newfoundland.

BACKGROUND: Tularemia is a rare zoonosis caused by Francisella tularensis, a small gram-negative intracellular coccobacillus. Transmission occurs through direct contact with small mammals such as hares and rabbits, exposure to ticks, or ingestion or inhalation of aerosolized particles. It is a highly variable disease with six subtypes based on clinical features. Tularemia is a very rare disease in Canada, with only 0.01 cases per 100,000 people reported in 2017. METHODS: In this case report, we describe two cases of tularemia affecting hunters from rural Newfoundland and Labrador. RESULTS: The first case describes a patient with glandular tularemia diagnosed with serology; the second describes a patient with typhoidal tularemia diagnosed on blood culture. Both patients recovered after treatment with gentamicin. DISCUSSION: These cases highlight the importance of eliciting a careful social history from patients presenting with an unexplained febrile illness. Tularemia should be considered in the differential diagnosis of fever after hunting in rural areas.

HISTORIQUE: La tularémie est une zoonose rare causée par le Francisella tularensis, un petit coccobacille intracellulaire à Gram négatif. La transmission se produit par contact direct avec des petits mammifères comme des lièvres et des lapins, l'exposition aux tiques, l'ingestion ou l'inhalation de particules aérosolisées. C'est une maladie extrêmement variable possédant six sous-types en fonction des caractéristiques cliniques. La tularémie est une maladie très rare au Canada; seulement 0,01 cas sur 100 000 habitants a été signalé en 2017. MÉTHODOLOGIE: Dans le présent rapport de cas, les auteurs décrivent deux cas de tularémie chez des chasseurs de régions rurales de Terre-Neuve-et-Labrador. RÉSULTATS: Le premier cas décrit un patient atteint de tularémie glandulaire diagnostiquée par sérologie et le deuxième, un patient atteint d'une tularémie typhoïde diagnostiquée par culture sanguine. Les deux patients se sont rétablis après avoir été traités à la gentamicine. DISCUSSION: Ces cas font ressortir l'importance d'une histoire sociale attentive des patients qui ont consulté à cause d'une maladie fébrile inexpliquée. Il faut envisager une tularémie lors du diagnostic différentiel de fièvre chez des personnes qui ont chassé dans des régions rurales.

Pharmacological FGF21 signals to glutamatergic neurons to enhance leptin action and lower body weight during obesity.

OBJECTIVE: Fibroblast growth factor 21 (FGF21) is a peripherally-derived endocrine hormone that acts on the central nervous system (CNS) to regulate whole body energy homeostasis. Pharmacological administration of FGF21 promotes weight loss in obese animal models and human subjects with obesity. However, the central targets mediating these effects are incompletely defined. METHODS: To explore the mechanism for FGF21's effects to lower body weight, we pharmacologically administer FGF21 to genetic animal models lacking the obligate FGF21 co-receptor, ß-klotho (KLB), in either glutamatergic (Vglut2-Cre) or GABAergic (Vgat-Cre) neurons. In addition, we abolish FGF21 signaling to leptin receptor (LepR-Cre) positive cells. Finally, we examine the synergistic effects of FGF21 and leptin to lower body weight and explore the importance of physiological leptin levels in FGF21-mediated regulation of body weight. RESULTS: Here we show that FGF21 signaling to glutamatergic neurons is required for FGF21 to modulate energy expenditure and promote weight loss. In addition, we demonstrate that FGF21 signals to leptin receptor-expressing cells to regulate body weight, and that central leptin signaling is required for FGF21 to fully stimulate body weight loss during obesity. Interestingly, co-administration of FGF21 and leptin synergistically leads to robust weight loss. CONCLUSIONS: These data reveal an important endocrine crosstalk between liver- and adipose-derived signals which integrate in the CNS to modulate energy homeostasis and body weight regulation.

Development of Inhalable ATRA-Loaded PLGA Nanoparticles as Host-Directed Immunotherapy against Tuberculosis.

Developing new effective treatment strategies to overcome the rise in multi-drug resistant tuberculosis cases (MDR-TB) represents a global challenge. A host-directed therapy (HDT), acting on the host immune response rather than Mtb directly, could address these resistance issues. We developed an HDT for targeted TB treatment, using All Trans Retinoic Acid (ATRA)-loaded nanoparticles (NPs) that are suitable for nebulization. Efficacy studies conducted on THP-1 differentiated cells infected with the H37Ra avirulent Mycobacterium tuberculosis (Mtb) strain, have shown a dose-dependent reduction in H37Ra growth as determined by the BACT/ALERT® system. Confocal microscopy images showed efficient and extensive cellular delivery of ATRA-PLGA NPs into THP-1-derived macrophages. A commercially available vibrating mesh nebulizer was used to generate nanoparticle-loaded droplets with a mass median aerodynamic diameter of 2.13 µm as measured by cascade impaction, and a volumetric median diameter of 4.09 µm as measured by laser diffraction. In an adult breathing simulation experiment, 65.1% of the ATRA PLGA-NP dose was inhaled. This targeted inhaled HDT could offer a new adjunctive TB treatment option that could enhance current dosage regimens leading to better patient prognosis and a decreasing incidence of MDR-TB.

Central FGF21 production regulates memory but not peripheral metabolism.

Fibroblast growth factor 21 (FGF21) is a liver-derived endocrine hormone that functions to regulate energy homeostasis and macronutrient intake. Recently, FGF21 was reported to be produced and secreted from hypothalamic tanycytes, to regulate peripheral lipid metabolism; however, rigorous investigation of FGF21 expression in the brain has yet to be accomplished. Using a mouse model that drives CRE recombinase in FGF21-expressing cells, we demonstrate that FGF21 is not expressed in the hypothalamus, but instead is produced from the retrosplenial cortex (RSC), an essential brain region for spatial learning and memory. Furthermore, we find that central FGF21 produced in the RSC enhances spatial memory but does not regulate energy homeostasis or sugar intake. Finally, our data demonstrate that administration of FGF21 prolongs the duration of long-term potentiation in the hippocampus and enhances activation of hippocampal neurons. Thus, endogenous and pharmacological FGF21 appear to function in the hippocampus to enhance spatial memory.

Troponin and short-term mortality in hospitalised patients with COVID-19 infection: a retrospective study in an inner-city London hospital.

OBJECTIVE: To investigate the association between troponin positivity in patients hospitalised with COVID-19 and increased mortality in the short term. SETTING: Homerton University Hospital, an inner-city district general hospital in East London. DESIGN: A single-centre retrospective observational study. PARTICIPANTS: All adults admitted with swab-proven RT-PCR COVID-19 to Homerton University Hospital from 4 February 2020 to 30 April 2020 (n=402). OUTCOME MEASURES: We analysed demographic and biochemical data collected from the patient record according to the primary outcome of death at 28 days during hospital admission. METHODS: Troponin positivity was defined above the upper limit of normal according to our local laboratory assay (>15.5 ng/L for females, >34 ng/L for males). Univariate and multivariate logistical regression analyses were performed to evaluate the link between troponin positivity and death. RESULTS: Mean age was 65.3 years for men compared with 63.8 years for women. A χ2 test showed survival of patients with COVID-19 was significantly higher in those with a negative troponin (p=3.23×10-10) compared with those with a positive troponin. In the multivariate logistical regression, lung disease, age, troponin positivity and continuous positive airway pressure were all significantly associated with death, with an area under the curve of 0.889, sensitivity of 0.886 and specificity of 0.629 for the model. Within this model, troponin positivity was independently associated with short-term mortality (OR 2.97, 95% CI 1.34 to 6.61, p=0.008). CONCLUSIONS: We demonstrated an independent association between troponin positivity and increased short-term mortality in COVID-19 in a London district general hospital.

Tany-Seq: Integrated Analysis of the Mouse Tanycyte Transcriptome.

The ability to maintain energy homeostasis is necessary for survival. Recently, an emerging role for ependymogial cells, which line the third ventricle in the hypothalamus in the regulation of energy homeostasis, has been appreciated. These cells are called tanycytes and are physically at the interface of brain communication with peripheral organs and have been proposed to mediate the transport of circulating hormones from the third ventricle into the parenchyma of the hypothalamus. Despite the important role tanycytes have been proposed to play in mediating communication from the periphery to the brain, we understand very little about the ontology and function of these cells due to their limited abundance and lack of ability to genetically target this cell population reliably. To overcome these hurdles, we integrated existing hypothalamic single cell RNA sequencing data, focusing on tanycytes, to allow for more in-depth characterization of tanycytic cell types and their putative functions. Overall, we expect this dataset to serve as a resource for the research community.