Clinical course and treatment interventions for adolescents who vaped during the COVID-19 pandemic.

Vaping nicotine and marijuana have been increasing among adolescents in the past 5 years. Tetrahydrocannabinol is the psychoactive cannabinoid in marijuana. The COVID-19 pandemic created gaps in healthcare access and visits, making it difficult to collect accurate data on adolescent vaping, willingness to quit and methods used to quit. In addition, the literature lacks information regarding effective evidence-based treatment measures for adolescents who vape. In this report, we seek to address this using two patient cases and detailing the interventions a managed care organisation enacted during this timeframe. Our investigation revealed a relationship between social stressors and vaping among teens. Addressing these underlying stressors and eliciting and treating mental health symptoms and polysubstance use appears to be critical to curbing vaping.

Isolation and characterization of ZK002, a novel dual function snake venom protein from Deinagkistrodon acutus with anti-angiogenic and anti-inflammatory properties.

Introduction: Pathological angiogenesis, the abnormal or excessive generation of blood vessels, plays an important role in many diseases including cancer, diabetic retinopathy, psoriasis, and arthritis. Additionally, increasing evidence supports the close linkage between angiogenesis and inflammation. Snake venoms are a rich natural source of biologically active molecules and carry rich potential for the discovery of anti-angiogenic and anti-inflammatory modulators. Methods: Here, we isolated and purified a novel protein, ZK002, from the venom of the snake Deinagkistrodon acutus, and investigated its anti-angiogenic and anti-inflammatory activities and mechanisms. Results: ZK002 was identified as a 30 kDa heterodimeric protein of α and ß chains, which exhibited anti-angiogenic activity in various in vitro assays. Mechanistically, ZK002 inhibited activation of VEGF signaling and related mediators including eNOS, p38, LIMK, and HSP27. ZK002 also upregulated the metalloproteinase inhibitor TIMP3 and inhibited components of the VEGF-induced signaling cascade, PPP3R2 and SH2D2A. The anti-angiogenic activity of ZK002 was confirmed in multiple in vivo models. ZK002 could also inhibit the in vitro expression of pro-inflammatory cytokines, as well as in vivo inflammation in the carrageenin-induced edema rat model. Conclusion: Our findings highlight the potential for further development of ZK002 as a dual function therapeutic against diseases with involvement of pathogenic angiogenesis and chronic inflammation.

Mapping the cellular and molecular landscape of cardiac non-myocytes in murine diabetic cardiomyopathy.

Diabetes is associated with a significantly elevated risk of heart failure. However, despite extensive efforts to characterize the phenotype of the diabetic heart, the molecular and cellular protagonists that underpin cardiac pathological remodeling in diabetes remain unclear, with a notable paucity of data regarding the impact of diabetes on non-myocytes within the heart. Here we aimed to define key differences in cardiac non-myocytes between spontaneously type-2 diabetic (db/db) and healthy control (db/h) mouse hearts. Single-cell transcriptomic analysis revealed a concerted diabetes-induced cellular response contributing to cardiac remodeling. These included cell-specific activation of gene programs relating to fibroblast hyperplasia and cell migration, and dysregulation of pathways involving vascular homeostasis and protein folding. This work offers a new perspective for understanding the cellular mediators of diabetes-induced cardiac pathology, and pathways that may be targeted to address the cardiac complications associated with diabetes.

Novel AT2R agonist, ß-Pro7Ang III, is cardio- and vaso-protective in diabetic spontaneously hypertensive rats.

Stimulation of the angiotensin II type 2 receptor (AT2R) evokes protective effects in various cardiovascular diseases. Thus, this study aimed to investigate the effects of AT2R stimulation, with or without AT1R blockade, in a model of hypertension with concomitant type 1 diabetes mellitus (T1DM). Spontaneously hypertensive rats (SHRs) were given either citrate or a single dose of streptozotocin (STZ; 55 mg/kg, i.p.) to induce diabetes. After 4 weeks of diabetes, animals were administered either a vehicle (saline), AT2R agonist, ß-Pro7Ang III (0.1 mg/kg/day via osmotic mini-pump), AT1R blocker, candesartan (2 mg/kg/day via drinking water), or a combination of both for a further 8 weeks. ß-Pro7Ang III treatment had no effect on blood pressure, but attenuated the significant increase in cardiac interstitial collagen and protein expression of fibrotic and inflammatory markers, and superoxide levels that was evident in diabetic SHRs. These effects were not observed with candesartan, despite its blood pressure lowering effects. Although ß-Pro7Ang III had no effect on aortic fibrosis, it significantly attenuated MCP-1 protein expression and superoxide levels when compared to both the non-diabetic and diabetic SHRs, to a similar extent as candesartan. In both the heart and vasculature, the effects of ß-Pro7Ang III in combination with candesartan were similar to those of ß-Pro7Ang III alone, and superior to candesartan alone. It was concluded that in hypertension with concomitant diabetes, AT2R stimulation with a novel ligand alone, or in combination with AT1R blockade, improved the cardiac and vascular structural changes that were strongly associated with inflammation and oxidative stress, independent of blood pressure regulation.

Validation of the Critical-Care Pain Observation Tool (CPOT) in pediatric patients undergoing orthopedic surgery.

Background: Postoperative pain cannot be measured accurately among many children with intellectual and developmental disabilities, resulting in underrecognition or delay in recognition of pain. The Critical-Care Pain Observation Tool (CPOT) is a pain assessment tool that has been widely validated in critically ill and postoperative adults. Aims: The objective of this study was to validate the CPOT for use with pediatric patients able to self-report and undergoing posterior spinal fusion surgery. Methods: Twenty-four patients (10-18 years old) scheduled to undergo surgery were consented to this repeated-measure, within-subject study. To examine discriminative and criterion validation, CPOT scores and patients' self-reports of pain intensity were collected prospectively by a bedside rater before, during, and after a nonnociceptive and nociceptive procedure on the day following surgery. Patients' behavioral reactions were video recorded at the bedside and retrospectively viewed by two independent video raters to examine interrater and intrarater reliability of CPOT scores. Results: Discriminative validation was supported with higher CPOT scores during the nociceptive procedure than during the nonnociceptive procedure. Criterion validation was supported with a moderate positive correlation between the CPOT scores and the patients' self-reported pain intensity during the nociceptive procedure. A CPOT cutoff score of ≥2 was associated with the maximum sensitivity (61.3%) and specificity (94.1%). Reliability analyses revealed poor to moderate agreement between bedside and video raters and moderate to excellent consistency within video raters. Conclusions: These findings suggest that the CPOT may be a valid tool to detect pain in pediatric patients in the acute postoperative inpatient care unit after posterior spinal fusion.

Contexte: La douleur postopératoire ne peut pas être mesurée avec précision chez de nombreux enfants atteints de déficience intellectuelle et développementale, entraînant ainsi une méconnaissance ou un retard dans la reconnaissance de la douleur. Le Critical-Care Pain Observation Tool (CPOT) est un outil d'évaluation de la douleur qui a été largement validé chez les adultes gravement malades et postopératoires.Objectifs: L'objectif de cette étude était de valider le CPOT pour une utilisation auprès de patients pédiatriques capables d'autoévaluation et subissant une chirurgie de fusion vertébrale postérieure.Méthodes: Dans le cadre d'une étude intra-sujet, un consentement à cette mesure répétée a été obtenu pour vingt-quatre patients (10­18 ans) devant subir une intervention chirurgicale. Pour examiner la validation discriminante et de critère, les scores CPOT et les autoévaluations des patients concernant l'intensité de la douleur ont été collectés de manière prospective par un évaluateur au chevet du patient avant, pendant et après une procédure non nociceptive et nociceptive le lendemain de la chirurgie. Les réactions comportementales des patients ont été enregistrées sur vidéo au chevet du patient et visionnées rétrospectivement par deux des évaluateurs vidéo indépendants pour examiner la fiabilité des scores CPOT inter-évaluateurs et intra-évaluateurs.Résultats: La validation discriminante a été confirmée par l'obtention de scores plus élevés à l'échelle CPOT pendant la procédure nociceptive que pendant la procédure non nociceptive. La validation de critère a été confirmée par une corrélation positive modérée entre les scores sur l'échelle CPOT et l'intensité de la douleur autoévaluée par les patients pendant la procédure nociceptive. Un score-seuil ≥ 2 sur l'échelle CPOT a été associé à la sensibilité et la spécificité maximales (61,3 % et 94,1 %, respectivement). Les analyses de fiabilité ont révélé une concordance faible à modérée entre les évaluateurs de chevet et les évaluateurs vidéo, et une cocordance modérée à excellente parmi les évaluateurs vidéo.Conclusions: Ces résultats indiquent que le CPOT peut être un outil valide pour détecter la douleur chez les enfants patients de l'unité de soins hospitaliers postopératoires aigus après une fusion rachidienne postérieure.

A high-sucrose diet exacerbates the left ventricular phenotype in a high fat-fed streptozotocin rat model of diabetic cardiomyopathy.

Left ventricular (LV) dysfunction is an early, clinically detectable sign of cardiomyopathy in type 2 diabetes mellitus (T2DM) that precedes the development of symptomatic heart failure. Preclinical models of diabetic cardiomyopathy are essential to develop therapies that may prevent or delay the progression of heart failure. This study examined the molecular, structural, and functional cardiac phenotype of two rat models of T2DM induced by a high-fat diet (HFD) with a moderate- or high-sucrose content (containing 88.9 or 346 g/kg sucrose, respectively), plus administration of low-dose streptozotocin (STZ). At 8 wk of age, male Sprague-Dawley rats commenced a moderate- or high-sucrose HFD. Two weeks later, rats received low-dose STZ (35 mg/kg ip for 2 days) and remained on their respective diets. LV function was assessed by echocardiography 1 wk before end point. At 22 wk of age, blood and tissues were collected postmortem. Relative to chow-fed sham rats, diabetic rats on a moderate- or high-sucrose HFD displayed cardiac reactive oxygen species dysregulation, perivascular fibrosis, and impaired LV diastolic function. The diabetes-induced impact on LV adverse remodeling and diastolic dysfunction was more apparent when a high-sucrose HFD was superimposed on STZ. In conclusion, a high-sucrose HFD in combination with low-dose STZ produced a cardiac phenotype that more closely resembled T2DM-induced cardiomyopathy than STZ diabetic rats subjected to a moderate-sucrose HFD.NEW & NOTEWORTHY Left ventricular dysfunction and adverse remodeling were more pronounced in diabetic rats that received low-dose streptozotocin (STZ) and a high-sucrose high-fat diet (HFD) compared with those on a moderate-sucrose HFD in combination with STZ. Our findings highlight the importance of sucrose content in diet composition, particularly in preclinical studies of diabetic cardiomyopathy, and demonstrate that low-dose STZ combined with a high-sucrose HFD is an appropriate rodent model of cardiomyopathy in type 2 diabetes.

Association of intraoperative dexmedetomidine use with postoperative hypotension in unilateral hip and knee arthroplasties: a historical cohort study.

PURPOSE: Dexmedetomidine is frequently used as a sedative agent for orthopedic surgery patients undergoing total hip or knee arthroplasty. Although the benefits of dexmedetomidine are well described in the literature, there is also potential for harm, especially regarding the hemodynamic effects of dexmedetomidine in the postoperative setting. METHODS: This historical cohort study included all primary unilateral total hip or knee arthroplasties conducted from April 2017 to February 2020 in a single, university-affiliated, tertiary care centre (Jewish General Hospital, Montreal, QC, Canada). We used multivariable logistic regression to analyze the predictors for postoperative hypotension, defined as a systolic blood pressure < 90 mm Hg or any systolic blood pressure while on a vasopressor infusion in the postanesthesia care unit. Models were validated using calibration and discrimination with bootstrapping technique. RESULTS: One thousand five hundred and eighty-eight patients were included in this study. Postoperative hypotension occurred in 413 (26%) patients. Statistically significant predictors for postoperative hypotension included female sex (adjusted odds ratio [aOR], 3.24; 95% confidence interval [CI], 2.29 to 4.58), a history of transient ischemic attack or cerebrovascular accident (aOR, 1.97; 95% CI, 1.04 to 3.72), and intraoperative dexmedetomidine use (aOR, 2.61; 95% CI, 1.99 to 3.42). Moreover, the risk of postoperative hypotension was approximately two times higher than baseline, with a total intraoperative dexmedetomidine dose above 50 µg (relative risk, 1.99; 95% CI, 1.63 to 2.44; P < 0.001). A higher preoperative systolic blood pressure (aOR, 0.98; 95% CI, 0.97 to 0.99) was a protective factor for postoperative hypotension. CONCLUSION: In this historical cohort study, dexmedetomidine was a strong risk factor for postoperative hypotension in total hip or knee arthroplasty patients. Dexmedetomidine, and particularly at high cumulative doses above 50 µg, should be administered judiciously in high-risk surgical patients to minimize the risk of postoperative hypotension.

RéSUMé: OBJECTIF: La dexmédétomidine est fréquemment utilisée comme agent sédatif pour les patients en chirurgie orthopédique bénéficiant d'une arthroplastie totale de la hanche ou du genou. Bien que les avantages de la dexmédétomidine soient bien décrits dans la littérature, il existe également un potentiel de préjudice, en particulier en ce qui touche aux effets hémodynamiques de la dexmédétomidine dans un contexte postopératoire. MéTHODE: Cette étude de cohorte historique comprenait toutes les arthroplasties totales unilatérales primaires de la hanche ou du genou réalisées entre avril 2017 et février 2020 dans un seul centre de soins tertiaires universitaire (Hôpital général juif, Montréal, QC, Canada). Nous avons utilisé la régression logistique multivariable pour analyser les prédicteurs d'hypotension postopératoire, définie comme une tension artérielle systolique < 90 mmHg ou toute tension artérielle systolique pendant une perfusion de vasopresseurs en salle de réveil. Les modèles ont été validés à l'aide de l'étalonnage et de la discrimination avec une technique d'auto-amorçage. RéSULTATS: Mille cinq cent quatre-vingt-huit patients ont été inclus dans cette étude. Une hypotension postopératoire est survenue chez 413 (26 %) patients. Les prédicteurs statistiquement significatifs d'une hypotension postopératoire comprenaient le sexe féminin (rapport de cotes ajusté [RCA], 3,24; intervalle de confiance [IC] à 95 %, 2,29 à 4,58), des antécédents d'accident ischémique transitoire ou d'accident vasculaire cérébral (RCA, 1,97; IC 95 %, 1,04 à 3,72) et l'utilisation peropératoire de dexmédétomidine (RCA, 2,61; IC 95 %, 1,99 à 3,42). De plus, le risque d'hypotension postopératoire était environ deux fois plus élevé que la valeur initiale, avec une dose peropératoire totale de dexmédétomidine supérieure à 50 µg (risque relatif, 1,99; IC 95 %, 1,63 à 2,44; P < 0,001). Une tension artérielle systolique préopératoire plus élevée (RCA, 0,98; IC 95 %, 0,97 à 0,99) était un facteur protecteur contre l'hypotension postopératoire. CONCLUSION: Dans cette étude de cohorte historique, la dexmédétomidine était un facteur de risque important d'hypotension postopératoire chez les patients bénéficiant d'une arthroplastie totale de la hanche ou du genou. La dexmédétomidine, et en particulier à des doses cumulatives élevées supérieures à 50 µg, devrait être administrée judicieusement chez les patients chirurgicaux à haut risque afin de minimiser le risque d'hypotension postopératoire.

Experience and Management of the Adverse Effects of Analgesics After Surgery: A Pediatric Patient Perspective.

After surgery, the adverse effects (AEs) of analgesics are common and critical factors influencing the postoperative experience of pediatric patients. Inadequate management of AEs has been found to prolong hospital stay, increase readmission rates and decrease satisfaction with care. The aim of this qualitative descriptive study was to better understand the AEs of analgesics from the perspective of adolescent patients with idiopathic scoliosis after spinal surgery. A total of 7 patients participated in the study. Semistructured interviews were conducted at discharge and 1 week after discharge. Transcribed data were analyzed using qualitative content analysis and themes were identified. Overall, participants most frequently reported gastrointestinal and cognitive AEs, with constipation being the most persistent and bothersome. The pediatric participants used a combination of 3 strategies to mitigate analgesic AEs, namely pharmacologic, nonpharmacologic, and reduction of analgesic intake. Participants demonstrated a lack of understanding of AEs and involvement in their own care. Future studies should be conducted to evaluate the efficacy of nonpharmacological strategies in managing analgesic AEs for pediatric patients after surgery.

Cardioprotective actions of nitroxyl donor Angeli's salt are preserved in the diabetic heart and vasculature in the face of nitric oxide resistance.

BACKGROUND AND PURPOSE: The risk of fatal cardiovascular events is increased in patients with type 2 diabetes mellitus (T2DM). A major contributor to poor prognosis is impaired nitric oxide (NO•) signalling at the level of tissue responsiveness, termed NO• resistance. This study aimed to determine if T2DM promotes NO• resistance in the heart and vasculature and whether tissue responsiveness to nitroxyl (HNO) is affected. EXPERIMENTAL APPROACH: At 8 weeks of age, male Sprague-Dawley rats commenced a high-fat diet. After 2 weeks, the rats received low-dose streptozotocin (two intraperitoneal injections, 35 mg·kg-1 , over two consecutive days) and continued on the same diet. Twelve weeks later, isolated hearts were Langendorff-perfused to assess responses to the NO• donor diethylamine NONOate (DEA/NO) and the HNO donor Angeli's salt. Isolated mesenteric arteries were utilised to measure vascular responsiveness to the NO• donors sodium nitroprusside (SNP) and DEA/NO, and the HNO donor Angeli's salt. KEY RESULTS: Inotropic, lusitropic and coronary vasodilator responses to DEA/NO were impaired in T2DM hearts, whereas responses to Angeli's salt were preserved or enhanced. Vasorelaxation to Angeli's salt was augmented in T2DM mesenteric arteries, which were hyporesponsive to the relaxant effects of SNP and DEA/NO. CONCLUSION AND IMPLICATIONS: This is the first evidence that inotropic and lusitropic responses are preserved, and NO• resistance in the coronary and mesenteric vasculature is circumvented, by the HNO donor Angeli's salt in T2DM. These findings highlight the cardiovascular therapeutic potential of HNO donors, especially in emergencies such as acute ischaemia or heart failure.

In vitro assessment and phase I randomized clinical trial of anfibatide a snake venom derived anti-thrombotic agent targeting human platelet GPIbα.

The interaction of platelet GPIbα with von Willebrand factor (VWF) is essential to initiate platelet adhesion and thrombosis, particularly under high shear stress conditions. However, no drug targeting GPIbα has been developed for clinical practice. Here we characterized anfibatide, a GPIbα antagonist purified from snake (Deinagkistrodon acutus) venom, and evaluated its interaction with GPIbα by surface plasmon resonance and in silico modeling. We demonstrated that anfibatide interferds with both VWF and thrombin binding, inhibited ristocetin/botrocetin- and low-dose thrombin-induced human platelet aggregation, and decreased thrombus volume and stability in blood flowing over collagen. In a single-center, randomized, and open-label phase I clinical trial, anfibatide was administered intravenously to 94 healthy volunteers either as a single dose bolus, or a bolus followed by a constant rate infusion of anfibatide for 24 h. Anfibatide inhibited VWF-mediated platelet aggregation without significantly altering bleeding time or coagulation. The inhibitory effects disappeared within 8 h after drug withdrawal. No thrombocytopenia or anti-anfibatide antibodies were detected, and no serious adverse events or allergic reactions were observed during the studies. Therefore, anfibatide was well-tolerated among healthy subjects. Interestingly, anfibatide exhibited pharmacologic effects in vivo at concentrations thousand-fold lower than in vitro, a phenomenon which deserves further investigation.Trial registration: Clinicaltrials.gov NCT01588132.

Slounase, a Batroxobin Containing Activated Factor X Effectively Enhances Hemostatic Clot Formation and Reducing Bleeding in Hypocoagulant Conditions in Mice.

Uncontrolled bleeding associated with trauma and surgery is the leading cause of preventable death. Batroxobin, a snake venom-derived thrombin-like serine protease, has been shown to clot fibrinogen by cleaving fibrinopeptide A in a manner distinctly different from thrombin, even in the presence of heparin. The biochemical properties of batroxobin and its effect on coagulation have been well characterized in vitro. However, the efficacy of batroxobin on hemostatic clot formation in vivo is not well studied due to the lack of reliable in vivo hemostasis models. Here, we studied the efficacy of batroxobin and slounase, a batroxobin containing activated factor X, on hemostatic clot composition and bleeding using intravital microcopy laser ablation hemostasis models in micro and macro vessels and liver puncture hemostasis models in normal and heparin-induced hypocoagulant mice. We found that prophylactic treatment in wild-type mice with batroxobin, slounase and activated factor X significantly enhanced platelet-rich fibrin clot formation following vascular injury. In heparin-treated mice, batroxobin treatment resulted in detectable fibrin formation and a modest increase in hemostatic clot size, while activated factor X had no effect. In contrast, slounase treatment significantly enhanced both platelet recruitment and fibrin formation, forming a stable clot and shortening bleeding time and blood loss in wild-type and heparin-treated hypocoagulant mice. Our data demonstrate that, while batroxobin enhances fibrin formation, slounase was able to enhance hemostasis in normal mice and restore hemostasis in hypocoagulant conditions via the enhancement of fibrin formation and platelet activation, indicating that slounase is more effective in controlling hemorrhage.

Predicting Acute Postoperative Pain Trajectories and Long-Term Outcomes of Adolescents after Spinal Fusion Surgery.

Objectives: Acute pain trajectories are associated with long-term outcomes such as persistent pain and functional disability in adults. However, there are limited data on acute postoperative pain trajectories in the pediatric population. The aims of this study were to investigate acute postoperative pain trajectories, their predictors, and their impact on long- term outcomes in adolescents with idiopathic scoliosis. Methods: We evaluated the preoperative pain intensity, use of analgesics, psychosocial measures and physical functioning of adolescents scheduled to undergo spinal fusion, and their average 6-hour self-reported pain intensity scores for their entire hospital stay. Six months after surgery, baseline variables were reassessed. We used growth mixture modeling to conduct acute postoperative pain trajectory analysis and to identify predictors of pain trajectories. Generalized linear models were conducted to determine whether acute pain trajectories predict long-term outcomes. Results: One hundred and six patients were included in the best-fitted acute pain trajectory model that included four classes that differed in initial pain intensity and rates of change over time. Preoperative pain catastrophizer status and use of analgesics significantly predicted pain trajectory membership. Furthermore, at the 6-month follow-up, patients experiencing moderate-to-severe pain in the acute postoperative period were more likely to report higher levels of pain severity, use pain medication, and miss a greater number of school/work days due to back pain in the last three months. Discussion. Preoperative assessment and analyzing the progression of pain in the acute postoperative period can help identify those at risk of negative long-term outcomes after surgery.

Improving the throughput of immunoaffinity purification and enzymatic digestion of therapeutic proteins using membrane-immobilized reagent technology.

Continued interest in protein therapeutics has motivated the development of improved bioanalytical tools to support development programs. LC-MS offers specificity, sensitivity, and multiplexing capabilities without the need for target-specific reagents, making it a valuable alternative to ligand binding assays. Immunoaffinity purification (IP) and enzymatic digestion are critical, yet extensive and time-consuming components of the "gold standard" bottom-up approach to LC-MS-based protein quantitation. In the present work, commercially available technology, based on membrane-immobilized reagents in spin column and plate format, is applied to reduce IP and digestion times from hours to minutes. For a standard monoclonal antibody, the lower limit of quantitation was 0.1 ng µL-1 compared to 0.05 ng µL-1 for the standard method. A pharmacokinetics (PK) study dosing Herceptin in rat was analyzed by both the membrane and the standard method with a total sample processing time of 4 h and 20 h, respectively. The calculated concentrations at each time point agreed within 8% between both methods, and PK values including area under the curve (AUC), half-life (T1/2), mean residence time (MRT), clearance (CL), and volume of distribution (Vdss) agreed within 6% underscoring the utility of the membrane methodology for quantitative bioanalysis workflows.

Depression and disclosure behavior via social media: A study of university students in China.

Severe stress and depression constitute serious challenges to people in both personal and public health. Numerous university students suffer from depression each year while only fractions of them receive proper and competent treatments. Following the trends of the era, social media has been prevalent among university students and become a new platform to disclose depression references. The purpose of this study is to examine the effects of various stressors and the "Big Five" personality traits towards the intention of disclosing depression. Addition to the disclosure intention, this study also explores if respondents have presented their depression via social media profiles. Over 200 WeChat users were surveyed on their experiences from psychological stress factors under four categories - academy, relationship and practical issues.

The Novel Small-molecule Annexin-A1 Mimetic, Compound 17b, Elicits Vasoprotective Actions in Streptozotocin-induced Diabetic Mice.

The formyl peptide receptor (FPR) family are a group of G-protein coupled receptors that play an important role in the regulation of inflammatory processes. It is well-established that activation of FPRs can have cardioprotective properties. Recently, more stable small-molecule FPR1/2 agonists have been described, including both Compound 17b (Cmpd17b) and Compound 43 (Cmpd43). Both agonists activate a range of signals downstream of FPR1/2 activation in human-engineered FPR-expressing cells, including ERK1/2 and Akt. Importantly, Cmpd17b (but not Cmpd43) favours bias away from intracellular Ca2+ mobilisation in this context, which has been associated with greater cardioprotection in response to Cmpd17b over Cmpd43. However, it is unknown whether these FPR agonists impact vascular physiology and/or elicit vasoprotective effects in the context of diabetes. First, we localized FPR1 and FPR2 receptors predominantly in vascular smooth muscle cells in the aortae of male C57BL/6 mice. We then analysed the vascular effects of Cmpd17b and Cmpd43 on the aorta using wire-myography. Cmpd17b but not Cmpd43 evoked a concentration-dependent relaxation of the mouse aorta. Removal of the endothelium or blockade of endothelium-derived relaxing factors using pharmacological inhibitors had no effect on Cmpd17b-evoked relaxation, demonstrating that its direct vasodilator actions were endothelium-independent. In aortae primed with elevated K+ concentration, increasing concentrations of CaCl2 evoked concentration-dependent contraction that is abolished by Cmpd17b, suggesting the involvement of the inhibition of Ca2+ mobilisation via voltage-gated calcium channels. Treatment with Cmpd17b for eight weeks reversed endothelial dysfunction in STZ-induced diabetic aorta through the upregulation of vasodilator prostanoids. Our data indicate that Cmpd17b is a direct endothelium-independent vasodilator, and a vasoprotective molecule in the context of diabetes.

Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries.

Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 µmol/L) and apamin (1 µmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 µmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 µmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 µmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.

Annexin-A1 deficiency exacerbates pathological remodelling of the mesenteric vasculature in insulin-resistant, but not insulin-deficient, mice.

BACKGROUND AND PURPOSE: Arterial stiffness, a characteristic feature of diabetes, increases the risk of cardiovascular complications. Potential mechanisms that promote arterial stiffness in diabetes include oxidative stress, glycation and inflammation. The anti-inflammatory protein annexin-A1 has cardioprotective properties, particularly in the context of ischaemia. However, the role of endogenous annexin-A1 in the vasculature in both normal physiology and pathophysiology remains largely unknown. Hence, this study investigated the role of endogenous annexin-A1 in diabetes-induced remodelling of mouse mesenteric vasculature. EXPERIMENTAL APPROACH: Insulin-resistance was induced in male mice (AnxA1+/+ and AnxA1-/- ) with the combination of streptozotocin (55mg/kg i.p. x 3 days) with high fat diet (42% energy from fat) or citrate vehicle with normal chow diet (20-weeks). Insulin-deficiency was induced in a separate cohort of mice using a higher total streptozocin dose (55mg/kg i.p. x 5 days) on chow diet (16-weeks). At study endpoint, mesenteric artery passive mechanics were assessed by pressure myography. KEY RESULTS: Insulin-resistance induced significant outward remodelling but had no impact on passive stiffness. Interestingly, vascular stiffness was significantly increased in AnxA1-/- mice when subjected to insulin-resistance. In contrast, insulin-deficiency induced outward remodelling and increased volume compliance in mesenteric arteries, regardless of genotype. In addition, the annexin-A1 / formyl peptide receptor axis is upregulated in both insulin-resistant and insulin-deficient mice. CONCLUSION AND IMPLICATIONS: Our study provided the first evidence that endogenous AnxA1 may play an important vasoprotective role in the context of insulin-resistance. AnxA1-based therapies may provide additional benefits over traditional anti-inflammatory strategies for reducing vascular injury in diabetes.

Nitric Oxide Resistance, Induced in the Myocardium by Diabetes, Is Circumvented by the Nitric Oxide Redox Sibling, Nitroxyl.

Aim: Impairment of tissue responsiveness to exogenous and endogenous nitric oxide (NO•), known as NO• resistance, occurs in many cardiovascular disease states, prominently in diabetes and especially in the presence of marked hyperglycemia. In this study, we sought to determine in moderate and severe diabetes (i) whether NO• resistance also occurs in the myocardium, and (ii) whether the NO• redox sibling nitroxyl (HNO) circumvents this. Results: The spectrum of acute NO• effects (induced by diethylamine-NONOate), including vasodilation, and enhanced myocardial contraction and relaxation were impaired by moderately diabetic rats ([blood glucose] ∼20 mM). In contrast, acute HNO effects (induced by isopropylamine-NONOate) were preserved even in more severe diabetes ([blood glucose] >28 mM). Intriguingly, the positive inotropic effects of HNO were significantly enhanced in diabetic rat hearts. Further, progressive attenuation of soluble guanylyl cyclase (sGC) contribution to myocardial NO• responses occurred with increasing severity of diabetes. Nevertheless, activation of sGC by HNO remained intact in the myocardium. Innovation: Diabetes is associated with marked attenuation of vascular and myocardial effects of NO and NO donors, and this NO• resistance is circumvented by HNO, suggesting potential therapeutic utility for HNO donors in cardiovascular emergencies in diabetics. Conclusion: These results provide the first evidence that NO• resistance occurs in diabetic hearts, and that HNO largely circumvents this problem. Further, the positive inotropic and lusitropic effects of HNO are enhanced in a severely diabetic myocardium, a finding that warrants further mechanistic interrogation. The results support a potential role for therapeutic HNO administration in acute treatment of ischemia and/or heart failure in diabetics.

Acute postoperative opioid consumption trajectories and long-term outcomes in pediatric patients after spine surgery.

Background: The days following surgery are a critical period where the use of opioids predicts long-term outcomes in adults. It is currently unknown as to whether opioid consumption throughout the acute postoperative period is associated with long-term outcomes in pediatric patients. The aims of this study were to characterize opioid consumption trajectories in the acute postoperative period, identify predictors of trajectory membership and determine associations between opioid consumption trajectories and long-term patient outcomes. Materials and methods: Medication use, pain and mental health status were assessed at baseline in adolescents with idiopathic scoliosis who were scheduled for spinal fusion surgery. Cumulative 6-hr opioid consumption was recorded for up to 5 days after spinal surgery. At 6 months after surgery, medication use, pain and functional activity were evaluated. Growth mixture modeling was used to identify opioid trajectories. Results: One hundred and six patients were included in the study. Mean cumulative 6-hr opioid consumption in the acute postoperative period was 13.23±5.20 mg/kg. The model with the best fit contained 5 acute postoperative trajectories and a quadratic term (AIC =6703.26, BIC =6767.19). Two types of patient behaviors were identified: high opioid consumers (trajectories 4 and 5) and low opioid consumers (trajectories 1, 2 and 3). Intraoperative intrathecal morphine dose was a predictor of trajectory membership (p=0.0498). Opioid consumption during the acute postoperative period was not significantly associated with pain, functional activity or pain medication use at 6 months after surgery. Conclusion: In pediatric patients, intraoperative intrathecal morphine dose predicts opioid consumption in the acute postoperative period. Importantly, opioid consumption during this period does not affect long-term outcomes in pediatric patients after a spine surgery.