Is there a role for biogenic amine receptors in mediating ß-phenylethylamine and RO5256390-induced vascular contraction?

BACKGROUND: Substantial evidence indicates trace amines can induce vasoconstriction independently of noradrenaline release. However, the mechanism underlying noradrenaline-independent vasoconstrictor responses to trace amines has not yet been established. This study evaluates the role of trace amine-associated receptor 1 (TAAR1) and other biogenic amine receptors in mediating ß-phenylethylamine and the TAAR-1 selective agonist RO5256390-induced vasoconstriction. METHODS: Vasoconstrictor responses to ß-PEA and the TAAR1-selective agonist, RO5256390 were assessed in vitro in endothelium-denuded aortic rings and third-order mesenteric arteries of male Sprague Dawley rats. RESULTS: ß-PEA and RO5256390 induced concentration-dependent vasoconstriction of aortic rings but not third-order mesenteric arteries. Vasoconstrictor responses in aortic rings were insensitive to antagonists of 5-HT. The murine-selective TAAR1 antagonist, EPPTB, had no effect on either ß-PEA or RO5256390-induced vasoconstriction. The α1-adrenoceptor antagonist, prazosin, and the α2-adrenoceptor antagonist, yohimbine, induced a shift of the ß-PEA concentration response curve too small to be ascribed to antagonism of α1-or α2-adrenoceptors, respectively. The α2-adrenoceptor antagonist atipamezole had no effect on ß-PEA or RO5256390-induced vasoconstriction. CONCLUSION: Vasoconstrictor responses to trace amines are not mediated by classical biogenic amine neurotransmitter receptors. Insensitivity of ß-PEA vasoconstrictor responses to EPPTB, may be explained by its low affinity for rat rather than murine TAAR1. Therefore, TAAR1 remains the most likely candidate receptor mediating vasoconstrictor responses to trace amines and that prazosin and yohimbine have low affinity for TAAR1.

More Than Under-Eye Bags: Treatment of Formidable Festoons.

A 64-year-old male with no medical care over the last decade was transferred from his local emergency room to a level 1 trauma center following an unwitnessed fall. Upon ophthalmic evaluation, he was noted to have significant lethargy and bilateral large festoons with secondary ectropion. Laboratory workup revealed severe hypothyroidism, consistent with myxedema coma, and his lethargy improved with medical treatment. The festoons were surgically removed to address the ectropion, and the patient was satisfied with the results following a single procedure. This case report features the largest reported festoons to date in the literature and emphasizes the importance of balancing cosmesis with function during surgical excision and correction of ectropion.

THE GODINA PRINCIPLE IN THE 21ST CENTURY: FREE FLAP TIMING AFTER ISOLATED LOWER EXTREMITY TRAUMA IN A RETROSPECTIVE NATIONAL COHORT.

BACKGROUND: The timing of free flap reconstruction after lower extremity trauma has been a controversial debate since Marko Godina's original 72 hour recommendation. Recent advances in microsurgery warrant an evaluation of the optimal time to reconstruction. METHODS: The Nationwide Readmission Database (2014-2019) was used to identify patients undergoing free flap reconstruction after lower extremity trauma. Risk-adjusted statistical methods were used to identify optimal time where risk of infectious and microsurgical complications increase and to quantify the risk associated with time delays. RESULTS: One-thousand and thirty patients undergoing reconstruction were identified. The mean time to flap coverage was 24.3 days. Thirty-three percent were performed within 72 hours, 24% from 72 hours-10 days, 18% from 10-30 days, and 24% after 30 days. Flaps performed after 10 days were associated with increased risk of surgical site infection, osteomyelitis, and other wound complications, compared to those performed within 72 hours. There was no increased risk in the period of 72 hours to 10 days. Revision amputation and microsurgical complications were not increased after 10 days. The predicted optimal cutoff was 9.5 days for microsurgical complications and 14.5 days for infectious complications. CONCLUSIONS: Advances in microsurgery may be responsible for extending the time in which definitive soft tissue coverage is required for wounds resulting from lower extremity trauma. Although it appears the original 72-hour time window can be safely extended, efforts should be made to refer patients to specialty limb salvage centers in a timely fashion.

PuCl3{CoCp[OP(OEt)2]3}: transuranic elements entering the field of heterometallic molecular chemistry.

Recent advances enabled the discovery of heterometallic molecules for many metals: main group, d-block, lanthanides, and some actinides (U, Th). These complexes have at least two different metals joined by bridging ligands or by direct metal-metal bonding interactions. They are attractive because they can enable chemical cooperativity between metals from different parts of the periodic table. Some heterometallics provide access to unique reactivity and others exhibit physical properties that cannot be accessed by homometallic species. We envisioned that transuranic heterometallics might similarly enable new transuranic chemistry, though synthetic routes to such compounds have yet to be developed. Reported here is the first synthesis of a molecular transuranic complex that contains plutonium (Pu) and cobalt (Co). Our analyses of PuCl3{CoCp[OP(OEt)2]3} showed Pu(iv) and Co(iii) were present and suggested that the Pu(iv) oxidation state was stabilized by the electron donating phosphite ligands. This synthetic method - and the demonstration that Pu(iv) can be stabilized in a heterobimetallic molecular setting - provides a foundation for further exploration of transuranic multimetallic chemistry.

Impact of Vertex Functionalization on Flexibility of Porous Organic Cages.

Efficient carbon capture requires engineered porous systems that selectively capture CO2 and have low energy regeneration pathways. Porous liquids (PLs), solvent-based systems containing permanent porosity through the incorporation of a porous host, increase the CO2 adsorption capacity. A proposed mechanism of PL regeneration is the application of isostatic pressure in which the dissolved nanoporous host is compressed to alter the stability of gases in the internal pore. This regeneration mechanism relies on the flexibility of the porous host, which can be evaluated through molecular simulations. Here, the flexibility of porous organic cages (POCs) as representative porous hosts was evaluated, during which pore windows decreased by 10-40% at 6 GPa. POCs with sterically smaller functional groups, such as the 1,2-ethane in the CC1 POC resulted in greater imine cage flexibility relative to those with sterically larger functional groups, such as the cyclohexane in the CC3 POC that protected the imine cage from the application of pressure. Structural changes in the POC also caused CO2 adsorption to be thermodynamically unfavorable beginning at ∼2.2 GPa in the CC1 POC, ∼1.1 GPa in the CC3 POC, and ∼1.0 GPa in the CC13 POC, indicating that the CO2 would be expelled from the POC at or above these pressures. Energy barriers for CO2 desorption from inside the POC varied based on the geometry of the pore window and all the POCs had at least one pore window with a sufficiently low energy barrier to allow for CO2 desorption under ambient temperatures. The results identified that flexibility of the CC1, CC3, or CC13 POCs under compression can result in the expulsion of captured gas molecules.

Proximal lateral insertion portal of an intra-articular arthroscopic stifle lever: A cadaveric study.

OBJECTIVE: To (1) Describe the proximal lateral insertion portal for the placement of an intra-articular distraction lever. (2) Assess for associated damage with the insertion of the lever and (3) evaluate the impact of duration of lever use on articular cartilage damage. STUDY DESIGN: Ex vivo canine cadaveric experimental study. ANIMALS: Paired canine stifles from seven cadavers (14 stifles from dogs weighing >20 kg). METHODS: A separate 0.5 cm proximal lateral portal was established adjacent to the lateral scope portal. A standard Ventura stifle thrust lever (VSTL) was inserted without removing the arthroscope. In Group A, the VSTL was placed in distraction for 5 min while in Group B the VSTL was placed for 10 min. The stifle joints were disarticulated and evaluated for associated damage to the long digital extensor tendon and iatrogenic articular cartilage injury (IACI) via India ink assay. RESULTS: No damage to the long digital extensor tendon was noted in any of the specimens during dissection. Superficial IACI was present in all specimens. There were no differences between groups when assessing for overall IACI. CONCLUSION: A proximal lateral portal and insertion of a standard VSTL can be performed without removing the arthroscope. CLINICAL SIGNIFICANCE: The use of a proximal lateral lever portal without repositioning the arthroscope was repeatable without damaging the long digital extensor tendon. A duration of up to 10 min in which the thrust lever was engaged did not result in increased visual cartilage damage.

Increased Patient Age as a Risk Factor Following Free Flap Reconstruction after Breast Cancer: A Single Institutional Review of 2,598 Cases.

BACKGROUND: Autologous breast reconstruction (ABR) after mastectomy is increasing due to benefits over implant-based reconstruction. However, free flap reconstruction is not universally offered to patients of advanced age due to perceived increased perioperative risk. METHODS: Patients undergoing free flap breast reconstruction at our institution from 2005 to 2018 were included. Risk-adjusted logistic regression models were fit while controlling for demographic and comorbid characteristics to determine the association of age with the probability of venous thromboembolism (VTE), delayed healing, skin necrosis, surgical site infection (SSI), seroma, hematoma, hernia, and flap loss. Linear predictions from risk-adjusted logistic regression models were used to create spline curves and determine the risk of outcomes associated with age. RESULTS: A cohort of 2,598 patients underwent free flap breast reconstruction in the period examined. The median age was 51 with approximately 9% of patients being 65 or older. Increased age was associated with a greater risk of delayed healing, skin necrosis, and hematoma after surgery. There was no increased risk of medical complications such as VTE or complications such as flap loss, seroma, or SSI. CONCLUSION: A set age cutoff for patients undergoing free flap breast reconstruction does not appear warranted. There is no difference in major surgical complications such as flap loss with increasing age. However, older age does predispose patients to specific wound complications such as hematoma, skin necrosis, and delayed wound healing, which should guide preoperative counseling. Further, medical complications do not increase with advanced age. Overall, however, the safety of ABR in older patients appears uncompromised.

Intramuscular diacylglycerol accumulates with acute hyperinsulinemia in insulin-resistant phenotypes.

Elevated skeletal muscle diacylglycerols (DAGs) and ceramides can impair insulin signaling, and acylcarnitines (acylCNs) reflect impaired mitochondrial fatty acid oxidation, thus, the intramuscular lipid profile is indicative of insulin resistance. Acute (i.e., postprandial) hyperinsulinemia has been shown to elevate lipid concentrations in healthy muscle and is an independent risk factor for type 2 diabetes (T2D). However, it is unclear how the relationship between acute hyperinsulinemia and the muscle lipidome interacts across metabolic phenotypes, thus contributing to or exacerbating insulin resistance. We therefore investigated the impact of acute hyperinsulinemia on the skeletal muscle lipid profile to help characterize the physiological basis in which hyperinsulinemia elevates T2D risk. In a cross-sectional comparison, endurance athletes (n = 12), sedentary lean adults (n = 12), and individuals with obesity (n = 13) and T2D (n = 7) underwent a hyperinsulinemic-euglycemic clamp with muscle biopsies. Although there were no significant differences in total 1,2-DAG fluctuations, there was a 2% decrease in athletes versus a 53% increase in T2D during acute hyperinsulinemia (P = 0.087). Moreover, C18 1,2-DAG species increased during the clamp with T2D only, which negatively correlated with insulin sensitivity (P < 0.050). Basal muscle C18:0 total ceramides were elevated with T2D (P = 0.029), but not altered by clamp. Acylcarnitines were universally lowered during hyperinsulinemia, with more robust reductions of 80% in athletes compared with only 46% with T2D (albeit not statistically significant, main effect of group, P = 0.624). Similar fluctuations with acute hyperinsulinemia increasing 1,2 DAGs in insulin-resistant phenotypes and universally lowering acylcarnitines were observed in male mice. In conclusion, acute hyperinsulinemia elevates muscle 1,2-DAG levels with insulin-resistant phenotypes. This suggests a possible dysregulation of intramuscular lipid metabolism in the fed state in individuals with low insulin sensitivity, which may exacerbate insulin resistance.NEW & NOTEWORTHY Postprandial hyperinsulinemia is a risk factor for type 2 diabetes and may increase muscle lipids. However, it is unclear how the relationship between acute hyperinsulinemia and the muscle lipidome interacts across metabolic phenotypes, thus contributing to insulin resistance. We observed that acute hyperinsulinemia elevates muscle 1,2-DAGs in insulin-resistant phenotypes, whereas ceramides were unaltered. Insulin-mediated acylcarnitine reductions are also hindered with high-fat feeding. The postprandial period may exacerbate insulin resistance in metabolically unhealthy phenotypes.

Myths and Methodologies: Standardisation in Human Physiology Research-Should We Control the Controllables?

The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.

Myths and Methodologies: Standardisation in human physiology research-should we control the controllables?

The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.

Extracorporeal Membrane Oxygenation-Associated Compartment Syndrome: Review of a National Database.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO)-associated compartment syndrome (CS) is a rare complication seen in critically ill patients. The epidemiology and management of ECMO-associated CS in the upper extremity (UE) and lower extremity (LE) are poorly defined in the literature. We sought to determine the epidemiology and characterize treatment and outcomes of UE-CS compared to LE-CS in the setting of ECMO therapy. METHODS: Adult patients undergoing ECMO therapy were identified in the Nationwide Readmission Database (2015-2019) and followed up for 6 months. Patients were stratified based on UE-CS versus LE-CS. Primary outcomes were fasciotomy and amputation. All-cause mortality and length of stay were also collected. Risk-adjusted modeling was performed to determine patient- and hospital-level factors associated with differences in the management UE-CS versus LE-CS while controlling for confounders. RESULTS: A total of 24,047 cases of ECMO during hospitalization were identified of which 598 were complicated by CS. Of this population, 507 cases were in the LE (84.8%), while 91 (15.5%) were in the UE. After multivariate analysis, UE-CS patients were less likely to undergo fasciotomy (50.5 vs. 70.9; P = 0.013) and were less likely to undergo amputation of the extremity (3.3 vs. 23.7; P = 0.001) although there was no difference in mortality (58.4 vs. 65.4; P = 0.330). CONCLUSIONS: ECMO patients with CS experience high mortality and morbidity. UE-CS has lower rates of fasciotomy and amputations, compared to LE-CS, with similar mortality. Further studies are needed to elucidate the reasons for these differences.

Factors associated with late surgical correction of craniosynostosis: A decade-long review of the United States nationwide readmission database.

Late-repair craniosynostosis (LRC), defined as craniosynostosis surgery beyond 1 year of age, is often associated with increased complexity and potential complications. Our study analyzed data from the 2010-2019 Nationwide Readmissions Database to investigate patient factors related to LRC. Of 10 830 craniosynostosis repair cases, 17% were LRC. These patients were predominantly from lower-income families and had more comorbidities, indicating that socioeconomic status could be a significant contributor. LRC patients were typically treated at teaching hospitals and privately owned investment institutions. Our risk-adjusted analysis revealed that LRC patients were more likely to belong to the lowest-income quartile, receive treatment at privately owned investment hospitals, and use self-payment methods. Despite these challenges, the hospital stay duration did not significantly differ between the two groups. Interestingly, LRC patients faced a higher predicted mean total cost compared with those who had surgery before turning 1. This difference in cost did not translate to a longer length of stay, further emphasizing the complexity of managing LRC. These findings highlight the urgent need for earlier intervention in craniosynostosis cases, particularly in lower-income communities. The medical community must strive to improve early diagnosis and treatment strategies in order to mitigate the socioeconomic and health disparities observed in LRC patients.

Sendaway capillary NT-proBNP in pulmonary hypertension.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a biomarker of cardiac ventricular wall stress that is incorporated into pulmonary hypertension (PH) risk stratification models. Sendaway sampling may enable patients to perform NT-proBNP tests remotely. This UK-wide study aimed to assess the agreement of sendaway NT-proBNP with standard venous NT-proBNP and to assess the effect of delayed processing. METHODS: Reference venous NT-proBNP was collected from PH patients. Samples for capillary and venous sendaway tests were collected contemporaneously, mailed to a reference laboratory and processed at 3 and 7 days using a Roche Cobas e411 device. Differences in paired measurements were analysed with Passing-Bablok regression, percentage difference plots and the % difference in risk strata. RESULTS: 113 patients were included in the study. 13% of day 3 capillary samples were insufficient. Day 3 capillary samples were not equivalent to reference samples (Passing Bablok analysis slope of 0.91 (95% CI 0.88 to 0.93) and intercept of 6.0 (95% CI 0.2 to 15.9)). The relative median difference was -7% and there were acceptable limits of agreement. Day 3 capillary NT-proBNP accurately risk stratified patients in 93.5% of cases. By comparison, day 3 venous results accurately risk stratified patients in 90.1% of cases and were equivalent by Passing-Bablok regression. Delayed sampling of sendaway tests led to an unacceptable level of agreement and systematically underestimated NT-proBNP. CONCLUSIONS: Sendaway NT-proBNP sampling may provide an objective measure of right ventricular strain for virtual PH clinics. Results must be interpreted with caution in cases of delayed sampling.

A single bout of vigorous intensity exercise enhances the efficacy of rituximab against human chronic lymphocytic leukaemia B-cells ex vivo.

Chronic lymphocytic leukaemia (CLL) is characterised by the clonal proliferation and accumulation of mature B-cells and is often treated with rituximab, an anti-CD20 monoclonal antibody immunotherapy. Rituximab often fails to induce stringent disease eradication, due in part to failure of antibody-dependent cellular cytotoxicity (ADCC) which relies on natural killer (NK)-cells binding to rituximab-bound CD20 on B-cells. CLL cells are diffusely spread across lymphoid and other bodily tissues, and ADCC resistance in survival niches may be due to several factors including low NK-cell frequency and a suppressive stromal environment that promotes CLL cell survival. It is well established that exercise bouts induce a transient relocation of NK-cells and B-cells into peripheral blood, which could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab in blood. In this pilot study, n = 20 patients with treatment-naïve CLL completed a bout of cycling 15 % above anaerobic threshold for âˆ¼ 30-minutes, with blood samples collected pre-, immediately post-, and 1-hour post-exercise. Flow cytometry revealed that exercise evoked a 254 % increase in effector (CD3-CD56+CD16+) NK-cells in blood, and a 67 % increase in CD5+CD19+CD20+ CLL cells in blood (all p < 0.005). NK-cells were isolated from blood samples pre-, and immediately post-exercise and incubated with primary isolated CLL cells with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab-mediated cell lysis increased by 129 % following exercise (p < 0.001). Direct NK-cell lysis of CLL cells - independent of rituximab - was unchanged following exercise (p = 0.25). We conclude that exercise improved the efficacy of rituximab-mediated ADCC against autologous CLL cells ex vivo and propose that exercise should be explored as a means of enhancing clinical responses in patients receiving anti-CD20 immunotherapy.

A Comprehensive Allele Specific Expression Resource for the Equine Transcriptome.

Background: Allele-specific expression (ASE) analysis provides a nuanced view of cis-regulatory mechanisms affecting gene expression. Results: In this work, we introduce and highlight the significance of an equine ASE analysis, containing integrated long- and short-read RNA sequencing data, along with insight from histone modification data, from four healthy Thoroughbreds (2 mares and 2 stallions) across 9 tissues. Conclusions: This valuable publicly accessible resource is poised to facilitate investigations into regulatory variation in equine tissues and foster a deeper understanding of the impact of allelic imbalance in equine health and disease at the molecular level.

Protocol to reveal the binding partner of secreted housekeeping enzymes in Listeria monocytogenes via in silico prediction to in vivo validation.

Numerous interacting protein partners exist without recognized interactive domains, necessitating a standardized methodology to decipher more in-depth interaction profiles. Here, we present a protocol to reveal the binding partner of a secreted housekeeping enzyme, alcohol acetaldehyde dehydrogenase (Listeria adhesion protein), in Listeria monocytogenes through in silico modeling and in vivo experiments. We describe steps for target protein modeling, biophysical profiling, ClusPro docking optimization, protein variant modeling, and docking comparison. We then provide detailed procedures for in vitro and in vivo protein binding validation. For complete details on the use and execution of this protocol, please refer to Liu et al.1.

Quasiparticle Poisoning of Superconducting Qubits from Resonant Absorption of Pair-Breaking Photons.

The ideal superconductor provides a pristine environment for the delicate states of a quantum computer: because there is an energy gap to excitations, there are no spurious modes with which the qubits can interact, causing irreversible decay of the quantum state. As a practical matter, however, there exists a high density of excitations out of the superconducting ground state even at ultralow temperature; these are known as quasiparticles. Observed quasiparticle densities are of order 1 µm^{-3}, tens of orders of magnitude greater than the equilibrium density expected from theory. Nonequilibrium quasiparticles extract energy from the qubit mode and can induce dephasing. Here we show that a dominant mechanism for quasiparticle poisoning is direct absorption of high-energy photons at the qubit junction. We use a Josephson junction-based photon source to controllably dose qubit circuits with millimeter-wave radiation, and we use an interferometric quantum gate sequence to reconstruct the charge parity of the qubit. We find that the structure of the qubit itself acts as a resonant antenna for millimeter-wave radiation, providing an efficient path for photons to generate quasiparticles. A deep understanding of this physics will pave the way to realization of next-generation superconducting qubits that are robust against quasiparticle poisoning.

The clinical utility of PET/CT scan and tissue biopsy in the management and follow-up of paediatric Hodgkin lymphoma in South Africa.

BACKGROUND: In low- to middle-income countries (LMICs) like South Africa, there is a need to understand the clinical practices surrounding diagnosis and surveillance of paediatric Hodgkin lymphoma (HL) to reduce the burden on health systems. Understanding the clinical utility of PET/CT scans may decrease repeated tissue biopsies during disease surveillance. METHODS: This is a retrospective cohort study of patients aged less than 18 years treated for HL at Chris Hani Baragwanath Academic Hospital from 1 January 2009 to 31 December 2018. RESULTS: Fifty-four patients were included in the study; male-to-female ratio was 5:1 with a mean age of 9 years. Seventy per cent of patients (n = 38) received a PET/CT and tissue biopsy during their initial diagnostic workup, whereas 20.4% (n = 11) of patients received a PET/CT and tissue biopsy during surveillance. Tissue biopsy and PET/CT showed slight agreement (κ = 0.14) in diagnosing relapsed disease during surveillance. The false negative rate for tissue biopsy during surveillance was 42.9%. Surveillance PET/CT showed a positive predictive value (PPV) of 66.7% and negative predictive value (NPV) of 100% when compared to tissue biopsy. CONCLUSION: This study is the first cohort to explore the clinical utility of PET/CT scans and tissue biopsies in a lowresourced setting. Our findings showed slight agreement between the modalities in diagnosing relapsed disease during surveillance. A portion of this discordance can be attributed to false negative tissue biopsy results. While the sample is limited, our findings are consistent with the high NPV of PET/CT scans of > 95% as is reported in the literature.