The Species Effect: Differential Sphingosine-1-Phosphate Responses in the Bone in Human Versus Mouse.

The deterioration of osteoblast-led bone formation and the upregulation of osteoclast-regulated bone resorption are the primary causes of bone diseases, including osteoporosis. Numerous circulating factors play a role in bone homeostasis by regulating osteoblast and osteoclast activity, including the sphingolipid-sphingosine-1-phosphate (S1P). However, to date no comprehensive studies have investigated the impact of S1P activity on human and murine osteoblasts and osteoclasts. We observed species-specific responses to S1P in both osteoblasts and osteoclasts, where S1P stimulated human osteoblast mineralisation and reduced human pre-osteoclast differentiation and mineral resorption, thereby favouring bone formation. The opposite was true for murine osteoblasts and osteoclasts, resulting in more mineral resorption and less mineral deposition. Species-specific differences in osteoblast responses to S1P were potentially explained by differential expression of S1P receptor 1. By contrast, human and murine osteoclasts expressed comparable levels of S1P receptors but showed differential expression patterns of the two sphingosine kinase enzymes responsible for S1P production. Ultimately, we reveal that murine models may not accurately represent how human bone cells will respond to S1P, and thus are not a suitable model for exploring S1P physiology or potential therapeutic agents.

Therapeutic avenues in bone repair: Harnessing an anabolic osteopeptide, PEPITEM, to boost bone growth and prevent bone loss.

The existing suite of therapies for bone diseases largely act to prevent further bone loss but fail to stimulate healthy bone formation and repair. We describe an endogenous osteopeptide (PEPITEM) with anabolic osteogenic activity, regulating bone remodeling in health and disease. PEPITEM acts directly on osteoblasts through NCAM-1 signaling to promote their maturation and formation of new bone, leading to enhanced trabecular bone growth and strength. Simultaneously, PEPITEM stimulates an inhibitory paracrine loop: promoting osteoblast release of the decoy receptor osteoprotegerin, which sequesters RANKL, thereby limiting osteoclast activity and bone resorption. In disease models, PEPITEM therapy halts osteoporosis-induced bone loss and arthritis-induced bone damage in mice and stimulates new bone formation in osteoblasts derived from patient samples. Thus, PEPITEM offers an alternative therapeutic option in the management of diseases with excessive bone loss, promoting an endogenous anabolic pathway to induce bone remodeling and redress the imbalance in bone turnover.

Discovery of Alternative Binding Poses through Fragment-Based Identification of DHODH Inhibitors.

Dihydroorotate dehydrogenase (DHODH) is a mitochondrial enzyme that affects many aspects essential to cell proliferation and survival. Recently, DHODH has been identified as a potential target for acute myeloid leukemia therapy. Herein, we describe the identification of potent DHODH inhibitors through a scaffold hopping approach emanating from a fragment screen followed by structure-based drug design to further improve the overall profile and reveal an unexpected novel binding mode. Additionally, these compounds had low P-gp efflux ratios, allowing for applications where exposure to the brain would be required.

Genetic analysis of late-maturity α-amylase in twelve wheat populations.

MAIN CONCLUSION: Genetic loci, particularly those with an effect in the independent panel, could be utilised to further reduce LMA expression when used with favourable combinations of genes known to affect LMA. Late maturity α-amylase (LMA) is a grain quality defect involving elevated α-amylase within the aleurone of wheat (Triticum aestivum L.) grains. The genes known to affect expression are the reduced height genes Rht-B1 (chromosome 4B) and Rht-D1 (chromosome 4D), and an ent-copalyl diphosphate synthase gene (LMA-1) on chromosome 7B. Other minor effect loci have been reported, but these are poorly characterised and further genetic understanding is needed. In this study, twelve F4-derived populations were created through single seed descent, genotyped and evaluated for LMA. LMA-1 haplotype C and the Rht-D1b allele substantially reduced LMA expression. The alternative dwarfing genes Rht13 and Rht18 had no significant effect on LMA expression. Additional quantitative trait loci (QTL) were mapped at 16 positions in the wheat genome. Effects on LMA expression were detected for four of these QTL in a large independent panel of Australian wheat lines. The QTL detected in mapping populations and confirmed in the large independent panel provide further opportunity for selection against LMA, especially if combined with Rht-D1b and/or favourable haplotypes of LMA-1.

Neonatal Outcomes after Medications for Opioid Use Disorder during Pregnancy in a State Women's Prison Facility, 2016-2019.

OBJECTIVE: Although medications for opioid use disorder improve both maternal and neonatal outcomes, little is known about opioid-exposed infants born during episodes of incarceration. The study sought to examine birth outcomes for infants born with opioid exposure during perinatal incarceration. METHODS: Participants were identified from clinic rosters in a Southeastern women's prison (2016-2019). Included infants born to pregnant people with opioid use disorder incarcerated in the study facility at the time of delivery. We abstracted hospital length of stay, neonatal opioid withdrawal syndrome (NOWS) severity, and discharge plan from hospital records and report descriptive statistics, analysis of variance F tests, and chi-square tests to compare outcomes by opioid exposure type. RESULTS: There were 125 infants born after exposure to methadone (n = 34), buprenorphine (n = 15), oxycodone (n = 22), or no opioid medication (n = 54) during prenatal incarceration. Most infants exposed to methadone or buprenorphine had difficulty with eating, sleeping, or consoling (97% and 80%), and 59% and 47% were treated with medication for NOWS, respectively. The majority with prenatal opioid exposure required intervention for NOWS symptoms after their birthing parent was discharged to the prison. The average hospital length of stay was different for infants with no opioid, methadone, buprenorphine, and oxycodone exposure during incarceration (4, 15, 12, and 9 days, respectively, P < 0.001). CONCLUSIONS: Neonatal hospitalization experiences of infants with perinatal opioid exposures during maternal incarceration mirror those of similarly exposed infants born outside the context of incarceration, except for hospital length of stay. Consideration of avoiding separation of the parent-infant dyad may be needed to improve outcomes for these infants.

Development of small molecule inhibitors of natural killer group 2D receptor (NKG2D).

Natural killer group 2D (NKG2D) is a homodimeric activating immunoreceptor whose function is to detect and eliminate compromised cells upon binding to the NKG2D ligands (NKG2DL) major histocompatibility complex (MHC) molecules class I-related chain A (MICA) and B (MICB) and UL16 binding proteins (ULBP1-6). While typically present at low levels in healthy cells and tissue, NKG2DL expression can be induced by viral infection, cellular stress or transformation. Aberrant activity along the NKG2D/NKG2DL axis has been associated with autoimmune diseases due to the increased expression of NKG2D ligands in human disease tissue, making NKG2D inhibitors an attractive target for immunomodulation. Herein we describe the discovery and optimization of small molecule PPI (protein-protein interaction) inhibitors of NKG2D/NKG2DL. Rapid SAR was guided by structure-based drug design and accomplished by iterative singleton and parallel medicinal chemistry synthesis. These efforts resulted in the identification of several potent analogs (14, 21, 30, 45) with functional activity and improved LLE.

Exploring basic science knowledge retention within a cohort of undergraduate medical students in the United Kingdom: A longitudinal study.

BACKGROUND: Clinical reasoning is reliant on students having acquired a strong foundation in the basic sciences. However, there remains uncertainty regarding whether medical students are maintaining this knowledge over the span of their degrees. Therefore, this project aimed to assess long-term retention of basic science knowledge within a cohort of students from an undergraduate medical school in the United Kingdom (UK). METHODS: This longitudinal study followed a cohort of students, from their first to final year. In their final year, participants sat a bespoke formative basic science knowledge assessment that utilised 46 single-best-answer questions. To examine for long-term attainment differences, these scores were compared with those achieved in first-year assessments. RESULTS: Of the eligible students, 40% partook in the study (n = 22). Comparing assessment scores highlighted an enhancement in overall basic science knowledge between first and final year (p < 0.01). Although most basic science domains remained unchanged between both time points, anatomy and physiology scores increased (p = 0.03 and p = 0.02, respectively), whereas biochemistry scores were the only ones to decrease (p = 0.02). DISCUSSION: This project provides insight into how well students are retaining the basic sciences during their studies. Underperforming science domains were identified, alongside pedagogical explanations for their individual shortcomings; for instance, students' perceived relevance of a domain is seen as a driver for its retention. Subsequently, a group of recommendations were derived to reinforce the most affected domains. The inclusion of more questions on the underperforming sciences, in clinically focussed assessments, is one such suggestion.

Use of N-(4-aminophenyl)piperidine derivatization to improve organic acid detection with supercritical fluid chromatography-mass spectrometry.

The analysis of organic acids in complex mixtures by LC-MS can often prove challenging, especially due to the poor sensitivity of negative ionization mode required for detection of these compounds in their native (i.e., underivatized or untagged) form. These compounds have also been difficult to measure using supercritical fluid chromatography (SFC)-MS, a technique of growing importance for metabolomic analysis, with similar limitations based on negative ionization. In this report, the use of a high proton affinity N-(4-aminophenyl)piperidine derivatization tag is explored for the improvement of organic acid detection by SFC-MS. Four organic acids (lactic, succinic, malic, and citric acids) with varying numbers of carboxylate groups were derivatized with N-(4-aminophenyl)piperidine to achieve detection limits down to 0.5 ppb, with overall improvements in detection limit ranging from 25-to-2100-fold. The effect of the derivatization group on sensitivity, which increased by at least 200-fold for compounds that were detectable in their native form, and mass spectrometric detection are also described. Preliminary investigations into the separation of these derivatized compounds identified multiple stationary phases that could be used for complete separation of all four compounds by SFC. This derivatization technique provides an improved approach for the analysis of organic acids by SFC-MS, especially for those that are undetectable in their native form.

Dual Fragmentation Isobaric Tags for Metabolomics.

Isobaric tags typically leverage an a1 type fragmentation to produce constant mass reporter ions. While this motif allows for efficient reporter formation, isobaric tags lack structural diversity, which limits the number and type of isotopes that are synthetically available. Presented here are two examples of dual fragmentation isobaric tagging. The first example mimics the typical isobaric tag structure through trimethylamine neutral loss and cyclization. Subsequent fragmentation releases a constant mass reporter with high efficiency. This provides a route to create a variety of isobaric tags with regard to both the reporter and the balancer mass. The second example is a set of six-plex isobaric, thiol-reactive tags that produce constant mass reporters by a similar sequential fragmentation mechanism. A trimethylamine neutral loss allows for the incorporation of up to 13 total isotopes in the balancer region, while minimizing deuterium retention time shifts. A subsequent C-S bond cleavage produces a constant mass reporter in the low-mass region. The thiols investigated produced an average RSD of 14% and R2 of 0.98 when analyzed as a six-plex injection. Thiol metabolism was disrupted using the glutamyl-cysteine synthetase inhibitor buthionine sulfoximine (BSO). Endothelial cells were incubated with BSO and showed significant decreases in glutathione and cysteinyl-glycine compared to control. Overall, a new method to generate constant mass reporters using a dual fragmentation scheme is presented.

Feasibility and acceptability testing of CommSense: A novel communication technology to enhance health equity in clinician-patient interactions.

Background: Quality patient-clinician communication is paramount to achieving safe and compassionate healthcare, but evaluating communication performance during real clinical encounters is challenging. Technology offers novel opportunities to provide clinicians with actionable feedback to enhance their communication skills. Methods: This pilot study evaluated the acceptability and feasibility of CommSense, a novel natural language processing (NLP) application designed to record and extract key metrics of communication performance and provide real-time feedback to clinicians. Metrics of communication performance were established from a review of the literature and technical feasibility verified. CommSense was deployed on a wearable (smartwatch), and participants were recruited from an academic medical center to test the technology. Participants completed a survey about their experience; results were exported to SPSS (v.28.0) for descriptive analysis. Results: Forty (n = 40) healthcare participants (nursing students, medical students, nurses, and physicians) pilot tested CommSense. Over 90% of participants "strongly agreed" or "agreed" that CommSense could improve compassionate communication (n = 38, 95%) and help healthcare organizations deliver high-quality care (n = 39, 97.5%). Most participants (n = 37, 92.5%) "strongly agreed" or "agreed" they would be willing to use CommSense in the future; 100% (n = 40) "strongly agreed" or "agreed" they were interested in seeing information analyzed by CommSense about their communication performance. Metrics of most interest were medical jargon, interruptions, and speech dominance. Conclusion: Participants perceived significant benefits of CommSense to track and improve communication skills. Future work will deploy CommSense in the clinical setting with a more diverse group of participants, validate data fidelity, and explore optimal ways to share data analyzed by CommSense with end-users.

Preclinical characterization of ISB 1342, a CD38 × CD3 T-cell engager for relapsed/refractory multiple myeloma.

Although treatment of multiple myeloma (MM) with daratumumab significantly extends the patient's lifespan, resistance to therapy is inevitable. ISB 1342 was designed to target MM cells from patients with relapsed/refractory MM (r/r MM) displaying lower sensitivity to daratumumab. ISB 1342 is a bispecific antibody with a high-affinity Fab binding to CD38 on tumor cells on a different epitope than daratumumab and a detuned scFv domain affinity binding to CD3ε on T cells, to mitigate the risk of life-threatening cytokine release syndrome, using the Bispecific Engagement by Antibodies based on the TCR (BEAT) platform. In vitro, ISB 1342 efficiently killed cell lines with different levels of CD38, including those with a lower sensitivity to daratumumab. In a killing assay where multiple modes of action were enabled, ISB 1342 showed higher cytotoxicity toward MM cells compared with daratumumab. This activity was retained when used in sequential or concomitant combinations with daratumumab. The efficacy of ISB 1342 was maintained in daratumumab-treated bone marrow patient samples showing lower sensitivity to daratumumab. ISB 1342 induced complete tumor control in 2 therapeutic mouse models, unlike daratumumab. Finally, in cynomolgus monkeys, ISB 1342 displayed an acceptable toxicology profile. These data suggest that ISB 1342 may be an option in patients with r/r MM refractory to prior anti-CD38 bivalent monoclonal antibody therapies. It is currently being developed in a phase 1 clinical study.

In vitro and in vivo effects of zoledronic acid on senescence and senescence-associated secretory phenotype markers.

In addition to reducing fracture risk, zoledronic acid has been found in some studies to decrease mortality in humans and extend lifespan and healthspan in animals. Because senescent cells accumulate with aging and contribute to multiple co-morbidities, the non-skeletal actions of zoledronic acid could be due to senolytic (killing of senescent cells) or senomorphic (inhibition of the secretion of the senescence-associated secretory phenotype [SASP]) actions. To test this, we first performed in vitro senescence assays using human lung fibroblasts and DNA repair-deficient mouse embryonic fibroblasts, which demonstrated that zoledronic acid killed senescent cells with minimal effects on non-senescent cells. Next, in aged mice treated with zoledronic acid or vehicle for 8 weeks, zoledronic acid significantly reduced circulating SASP factors, including CCL7, IL-1ß, TNFRSF1A, and TGFß1 and improved grip strength. Analysis of publicly available RNAseq data from CD115+ (CSF1R/c-fms+) pre-osteoclastic cells isolated from mice treated with zoledronic acid demonstrated a significant downregulation of senescence/SASP genes (SenMayo). To establish that these cells are potential senolytic/senomorphic targets of zoledronic acid, we used single cell proteomic analysis (cytometry by time of flight [CyTOF]) and demonstrated that zoledronic acid significantly reduced the number of pre-osteoclastic (CD115+/CD3e-/Ly6G-/CD45R-) cells and decreased protein levels of p16, p21, and SASP markers in these cells without affecting other immune cell populations. Collectively, our findings demonstrate that zoledronic acid has senolytic effects in vitro and modulates senescence/SASP biomarkers in vivo. These data point to the need for additional studies testing zoledronic acid and/or other bisphosphonate derivatives for senotherapeutic efficacy.

Implantation of a Sutureless Valve Into a Stented Prosthesis: An Open Salvage Procedure.

BACKGROUND: A 78-year-old male was admitted to our institute with increasing shortness of breath and decreased exercise tolerance. His increasing symptoms were not relieved with medical management. He had a complex medical history that included aortic valve replacement (AVR). Echocardiography showed a deteriorating aortic bioprosthesis with severe aortic regurgitation. METHOD: Intraoperative extraction of this prosthesis proved technically challenging and a valve in valve successfully was implanted as a salvage procedure. RESULTS: The procedure was successful, and the patient made a full recovery. CONCLUSION: Open valve in valve implantation, despite technical difficulties, may be utilized as a salvage procedure.

Supercritical Fluid Nanospray Mass Spectrometry: II. Effects on Ionization.

Nanospraying supercritical fluids coupled to a mass spectrometer (nSF-MS) using a 90% supercritical fluid CO2 carrier (sCO2) has shown an enhanced desolvation compared to traditional liquid eluents. Capillaries of 25, 50, and 75 µm internal diameter (i.d.) with pulled emitter tips provided high MS detection sensitivity. Presented here is an evaluation of the effect of proton affinity, hydrophobicity, and nanoemitter tip size on the nSF-MS signal. This was done using a set of primary, secondary, tertiary, and quaternary amines with butyl, hexyl, octyl, and decyl chains as analytes. Each amine class was analyzed individually to evaluate hydrophobicity and proton affinity effects on signal intensity. The system has shown a mass sensitive detection on a linear dynamic range of 0.1-100 µM. Results indicate that hydrophobicity has a larger effect on the signal response than proton affinity. Nanospraying a mixture of all amine classes using the 75 µm emitter has shown a quaternary amine signal not suppressed by competing analytes. Competing ionization was observed for primary, secondary, and tertiary amines. The 75 and 50 µm emitters demonstrated increased signal with increasing hydrophobicity. Surprisingly, the 25 µm i.d. emitter yielded a signal decrease as the alkyl chain length increased, contrary to conventional understanding. Nanospraying the evaporative fluid in a sub-500 nm emitter likely resulted in differences in the ionization mechanism. Results suggest that 90% sCO2 with 9.99% methanol and 0.01% formic acid yielded fast desolvation, high ionization efficiency, and low matrix effect, which could benefit complex biological matrix analysis.

Identification of small-molecule protein-protein interaction inhibitors for NKG2D.

NKG2D (natural-killer group 2, member D) is a homodimeric transmembrane receptor that plays an important role in NK, γδ+, and CD8+ T cell-mediated immune responses to environmental stressors such as viral or bacterial infections and oxidative stress. However, aberrant NKG2D signaling has also been associated with chronic inflammatory and autoimmune diseases, and as such NKG2D is thought to be an attractive target for immune intervention. Here, we describe a comprehensive small-molecule hit identification strategy and two distinct series of protein-protein interaction inhibitors of NKG2D. Although the hits are chemically distinct, they share a unique allosteric mechanism of disrupting ligand binding by accessing a cryptic pocket and causing the two monomers of the NKG2D dimer to open apart and twist relative to one another. Leveraging a suite of biochemical and cell-based assays coupled with structure-based drug design, we established tractable structure-activity relationships with one of the chemical series and successfully improved both the potency and physicochemical properties. Together, we demonstrate that it is possible, albeit challenging, to disrupt the interaction between NKG2D and multiple protein ligands with a single molecule through allosteric modulation of the NKG2D receptor dimer/ligand interface.

In vitro and in vivo effects of zoledronate on senescence and senescence-associated secretory phenotype markers.

In addition to reducing fracture risk, zoledronate has been found in some studies to decrease mortality in humans and extend lifespan and healthspan in animals. Because senescent cells accumulate with aging and contribute to multiple co-morbidities, the non-skeletal actions of zoledronate could be due to senolytic (killing of senescent cells) or senomorphic (inhibition of the secretion of the senescence-associated secretory phenotype [SASP]) actions. To test this, we first performed in vitro senescence assays using human lung fibroblasts and DNA repair-deficient mouse embryonic fibroblasts, which demonstrated that zoledronate killed senescent cells with minimal effects on non-senescent cells. Next, in aged mice treated with zoledronate or vehicle for 8 weeks, zoledronate significantly reduced circulating SASP factors, including CCL7, IL-1ß, TNFRSF1A, and TGFß1 and improved grip strength. Analysis of publicly available RNAseq data from CD115+ (CSF1R/c-fms+) pre-osteoclastic cells isolated from mice treated with zoledronate demonstrated a significant downregulation of senescence/SASP genes (SenMayo). To establish that these cells are potential senolytic/senomorphic targets of zoledronate, we used single cell proteomic analysis (cytometry by time of flight [CyTOF]) and demonstrated that zoledronate significantly reduced the number of pre-osteoclastic (CD115+/CD3e-/Ly6G-/CD45R-) cells and decreased protein levels of p16, p21, and SASP markers in these cells without affecting other immune cell populations. Collectively, our findings demonstrate that zoledronate has senolytic effects in vitro and modulates senescence/SASP biomarkers in vivo . These data point to the need for additional studies testing zoledronate and/or other bisphosphonate derivatives for senotherapeutic efficacy.

Online comic-based art workshops as an innovative patient and public involvement and engagement approach for people with chronic breathlessness.

BACKGROUND: Talking about breathlessness can be emotionally challenging. People can feel a sense of illegitimacy and discomfort in some research contexts. Comic-based illustration (cartooning) offers an opportunity to communicate in a more creative and inclusive way. We used cartooning in patient and public involvement and engagement (PPIE) work to explore symptoms of breathlessness and their impact on peoples' everyday lives. MAIN BODY: Five, 90-min cartooning workshops were delivered online to members of Breathe Easy Darlington (UK). The workshop series involved 5-10 Breathe Easy members and were facilitated by a professional cartoonist supported by three researchers. The experience of living with breathlessness was represented via illustrations of cartoon characters and ideas explored in subsequent conversations. Cartooning was fun and the majority found it a nostalgic experience. Sharing the experience helped the research team develop new understandings of breathlessness and fostered relationships with the Breathe Easy members. The illustrations showed characters leaning against objects, sweating and sitting down, demonstrating living with the sensation of not being in control. CONCLUSION: Comic-based art, as a fun and innovative PPIE approach. It facilitated the research team becoming embedded in an existing group who will act as PPIE members on a long-term research programme. Illustrations enabled storytelling and fostered novel insights into the lived experiences of people with breathlessness including sensations of a loss of control, disorientation, and unsteadiness. This will impact on work investigating balance in people with chronic obstructive pulmonary disease. This model has potential to be applied in a range of PPIE and research contexts.

Talking about breathlessness can be difficult and cause feelings of anxiety. Involving people with breathlessness in research activities can also be challenging. Research contexts can make people feel uncomfortable as they may struggle to understand and feel like they don't belong. Comic-based illustration (cartooning) offers an opportunity to communicate in a different way. Cartooning was used with members of Breathe Easy Darlington, a support group for people with breathlessness, as a way of helping the research team understand how breathlessness impacts daily lives. Five 90-min cartooning workshops were delivered online and involved 5­10 Breathe Easy members per session. The sessions were led by a professional cartoonist whilst the research team facilitated discussions about breathlessness and related issues. The experience of living with breathlessness was illustrated via cartoon characters and ideas were explored through conversations about the illustrations. People found cartooning fun and sharing the experience with the research team helped them to become part of an existing group who will support a long-term research project directly impacting research investigating balance in people with lung disease. The Breathe Easy members were able to tell their stories via illustrations allowing the research team an insight into different aspects of living with breathlessness. The illustrations showed characters leaning against trees and chairs, sweating and sitting down. The need for physical support caused embarrassment, while people struggled to appear "normal". Conversations about the illustrations revealed that the idea of "balance" aligns with a loss of control, disorientation, and unsteadiness which causes intense fear and shame.

Discovery of OICR12694: A Novel, Potent, Selective, and Orally Bioavailable BCL6 BTB Inhibitor.

B cell lymphoma 6 (BCL6), a highly regulated transcriptional repressor, is deregulated in several forms of non-Hodgkin lymphoma (NHL), most notably in diffuse large B-cell lymphoma (DLBCL). The activities of BCL6 are dependent on protein-protein interactions with transcriptional co-repressors. To find new therapeutic interventions addressing the needs of patients with DLBCL, we initiated a program to identify BCL6 inhibitors that interfere with co-repressor binding. A virtual screen hit with binding activity in the high micromolar range was optimized by structure-guided methods, resulting in a novel and highly potent inhibitor series. Further optimization resulted in the lead candidate 58 (OICR12694/JNJ-65234637), a BCL6 inhibitor with low nanomolar DLBCL cell growth inhibition and an excellent oral pharmacokinetic profile. Based on its overall favorable preclinical profile, OICR12694 is a highly potent, orally bioavailable candidate for testing BCL6 inhibition in DLBCL and other neoplasms, particularly in combination with other therapies.

Clinical characteristics and predictors for hospitalisation during the initial phases of the Delta variant COVID-19 outbreak in Sydney, Australia.

OBJECTIVES: The COVID-19 Delta variant of concern continues to pose significant challenges to health systems globally, with increased transmissibility and different patient populations affected. In Sydney, a virtual model of care was implemented in response to the COVID-19 pandemic and Special Health Accommodation (SHA) was made available for community patients with COVID-19 who could not isolate at home or needed health support. METHODS: This retrospective observational cohort study of all patients with COVID-19 Delta variant in SHA during the initial phases of the Delta variant outbreak in Sydney describes the demographic and clinical characteristics of patients with Delta variant COVID-19 and determines predictors of need for in-patient hospital admission. RESULTS: Data from 794 patients were analysed. One hundred and fifty-seven patients (19.8%) were transferred to ED. Of those, 125 were admitted to an in-patient unit (admission rate from ED 79.6%), and of these 30 (24%) went to ICU and seven were intubated. Two patients died within the follow-up period. Age >40 years, obesity, and presence of fever (temperature >37.5°C), hypoxia (oxygen saturation <95%), tachycardia or gastrointestinal symptoms on initial assessment in SHA were independent predictors of in-patient admission with an AUROC of 0.78 (95% confidence interval 0.73, 0.82). CONCLUSIONS: Initial symptoms and vital signs were just as predictive for short-term deterioration as age and pre-existing comorbidities and should be included in future risk prediction models for COVID-19. Based on this, we derive a proposed risk prediction score that incorporates these predictors with further validation required.

Isobaric 6-plex and tosyl dual tagging for the determination of positional isomers and quantitation of monounsaturated fatty acids using rapid UHPLC-MS/MS.

Isobaric labelling of fatty acids is complicated by chromatographic co-elution of double bond isomers. This produces contaminated spectra which can mask important biological changes. Here two derivatization strategies are combined to improve throughput and produce MS2 reporters which change mass depending on double bond position. A 6-plex isobaric tag is attached to the acid group, followed by the tosylation of the double bond using chloramine-T. These two derivatizations allowed for the chromatographic resolution of nearly all investigated isomers using a 3.5 minute ultrafast method. Further isomer differentiation is achieved upon fragmentation as reporter masses scale with the double bond location. This occurs by a dual-fragmentation route which reveals the isobaric labelling and fragments along the double bond of each analyte. These unique fragments allowed for accurate quantitation of co-isolated double bond isomers where traditional isobaric tags would experience ratio distortion. Saturated and monounsaturated fatty acids were characterized by this rapid 6-plex method and produced an average signal RSD of 9.3% and R2 of 0.99. The method was then used to characterize fatty acid dysregulation upon inhibition of stearoyl CoA desaturase with CAY10566.