The 8-hydroxyquinoline derivative, clioquinol, is an alpha-1 adrenoceptor antagonist.

Clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) is an antimicrobial agent whose actions as a zinc or copper ionophore and an iron chelator revived the interest in similar compounds for the treatment of fungal and bacterial infections, neurodegeneration and cancer. Recently, we reported zinc ionophores, including clioquinol, cause vasorelaxation in isolated arteries through mechanisms that involve sensory nerves, endothelium and vascular smooth muscle. Here, we report that clioquinol also uniquely acts as a competitive alpha-1 (α1) adrenoceptor antagonist. We employed ex vivo functional vascular contraction and pharmacological techniques in rat isolated mesenteric arteries, receptor binding assays using stabilized solubilized α1 receptor variants, or wild-type human α1-adrenoceptors transfected in COS-7 cells (African green monkey kidney fibroblast-like cells), and molecular dynamics homology modelling based on the recently published α1A adrenoceptor cryo-EM and α1B crystal structures. At higher concentrations, all ionophores including clioquinol cause a non-competitive antagonism of agonist-mediated contraction due to intracellular zinc delivery, as reported previously. However, at lower concentration ranges, clioquinol has an additional mechanism of competitively inhibiting α1-adrenoceptors that contributes to decreasing vascular contractility. Molecular dynamic simulation showed that clioquinol binds stably to the orthosteric binding site (Asp106) of the receptor, confirming the structural basis for competitive α1-adrenoceptor antagonism by clioquinol.

Mechanisms by which the cystic fibrosis transmembrane conductance regulator may influence SARS-CoV-2 infection and COVID-19 disease severity.

Patients with cystic fibrosis (CF) exhibit pronounced respiratory damage and were initially considered among those at highest risk for serious harm from SARS-CoV-2 infection. Numerous clinical studies have subsequently reported that individuals with CF in North America and Europe-while susceptible to severe COVID-19-are often spared from the highest levels of virus-associated mortality. To understand features that might influence COVID-19 among patients with cystic fibrosis, we studied relationships between SARS-CoV-2 and the gene responsible for CF (i.e., the cystic fibrosis transmembrane conductance regulator, CFTR). In contrast to previous reports, we found no association between CFTR carrier status (mutation heterozygosity) and more severe COVID-19 clinical outcomes. We did observe an unexpected trend toward higher mortality among control individuals compared with silent carriers of the common F508del CFTR variant-a finding that will require further study. We next performed experiments to test the influence of homozygous CFTR deficiency on viral propagation and showed that SARS-CoV-2 production in primary airway cells was not altered by the absence of functional CFTR using two independent protocols. On the contrary, experiments performed in vitro strongly indicated that virus proliferation depended on features of the mucosal fluid layer known to be disrupted by absent CFTR in patients with CF, including both low pH and increased viscosity. These results point to the acidic, viscous, and mucus-obstructed airways in patients with cystic fibrosis as unfavorable for the establishment of coronaviral infection. Our findings provide new and important information concerning relationships between the CF clinical phenotype and severity of COVID-19.

Liposomal Bupivacaine Versus Continuous Nerve Block: Liposomal Bupivacaine May be Non-inferior and More Cost Effective.

BACKGROUND: Regional anesthesia with adductor canal block has become the standard of care for pain management after total knee arthroplasty (TKA). We hypothesized that liposomal bupivacaine (LB) may be noninferior to continuous nerve block with a pain pump in terms of average pain scores, 30- and 90-day readmissions, and emergency department (ED) visits while reducing cost. METHODS: A retrospective chart review was performed on primary TKA patients from 2015 to 2020 by 23 orthopaedic surgeons at a single institution. The inclusion criteria was treatment with LB or a pain pump, and exclusion criteria was receipt of both anesthetics and revision surgery. A total of 2,378 patients met the inclusion criteria with 1,640 patients treated with LB and 738 treated with the pain pump. Demographic differences were not statistically significant. Primary outcomes were average pain scores, 30- and 90-day readmissions, and ED visits. Secondary outcomes were average milligram morphine equivalents per admission, hospital lengths of stay , and costs. RESULTS: There was no significant difference in pain scores on postoperative days 0, 1, 2, or 3 (P = .77, .86, 0.08, and 0.40, respectively), 30- or 90- day readmissions (P = .527 and P = .374), ED visits (P = .129 and P = .108), milligram morphine equivalents utilizations (P = .194), or average hospital LOS (P = .348). We estimated a potential cost savings of $95 per patient and $155,800 over the course of the study. CONCLUSION: LB was found to be noninferior to a pain pump, and the transition to this medication was associated with cost savings.

Bone marrow necrosis and fat embolism syndrome in sickle cell disease during COVID-19 infection treated successfully with sequential red cell and plasma exchange.

Fat embolism syndrome (FES) is a rare life-threatening condition that is particularly seen in milder forms of sickle cell disease (SCD). Widespread systemic fat emboli are generated in the context of extensive bone marrow necrosis. Multi-organ failure with a high morbidity and mortality may quickly develop. Infection with Parvovirus B19 is a common precipitant. Here, the authors report the case of a 35-year-old Afro-Caribbean man with HbSC disease who presented with FES having tested positive for SARS-COV-2. He rapidly became critically ill and required admission to the intensive care unit for organ support. He was treated with red cell exchange and plasma exchange and made a good recovery to leave hospital at week 7.

Role of Phospholipases A2 in Vascular Relaxation and Sympatholytic Effects of Five Australian Brown Snake, Pseudonaja spp., Venoms in Rat Isolated Tissues.

Human envenoming by Australian brown snakes (Pseudonaja spp.) may result in potentially life-threatening hypotension and subsequent cardiovascular collapse. There have been relatively few studies of the cardiovascular and sympathetic effects of Pseudonaja spp. venoms. In this study, we have examined the effects of venom from five brown snake species-P. affinis, aspidorhyncha, inframacula, nuchalis, and textilis-on cardiac inotropic and chronotropic responses, vascular tone, and sympathetic nerve-induced vascular contractions in rat isolated tissues. The role of phospholipases A2 (PLA2s) in venom-induced effects was assessed with the sPLA2 inhibitor varespladib. In rat isolated left and right atria, there were no physiologically relevant effects of Pseudonaja venoms (0.1-30 µg/ml) on left atrial force of contraction (inotropy) or right atrial rate (chronotropy). In contrast, in isolated small mesenteric arteries precontracted with a thromboxane mimetic, each of the five brown snake venoms (at 30 µg/ml) caused marked vasorelaxation (-60 to -90% of contractile tone). Pretreatment with varespladib (1 µM) significantly inhibited the vasorelaxation caused by P. aspidorhyncha, P. nuchalis, and P. textilis venoms. Electrically induced sympathetic nerve-mediated contractions of mesenteric arteries were significantly attenuated by only P. textilis, and P. affinis venoms (30 µg/ml) and these sympatholytic effects were inhibited by varespladib (1 µM). Based on their inhibition with the sPLA2 inhibitor varespladib, we conclude that PLA2 toxins in P. aspidorhyncha, P. nuchalis, and P. textilis venoms are involved in brown snake venom-induced vasorelaxation and the sympatholytic effects of P. affinis, and P. textilis venoms. Our study supports the promising potential role of varespladib as an initial (pre-referral) and/or adjunct (in combination with antivenom) therapeutic agent for brown snake envenoming.

Pharmacological characterisation of the CB1 receptor antagonist activity of cannabidiol in the rat vas deferens bioassay.

Cannabidiol is increasingly considered for treatment of a wide range of medical conditions. Binding studies suggest that cannabidiol binds to CB1 receptors. In the rat isolated vas deferens bioassay, a single electrical pulse causes a biphasic contraction from nerve-released ATP and noradrenaline. WIN 55,212-2 acts on prejunctional CB1 receptors to inhibit release of these transmitters. In this bioassay, we tested whether cannabidiol and SR141716 were acting as competitive antagonists of this receptor. Monophasic contractions mediated by ATP or noradrenaline in the presence of prazosin or NF449 (P2X1 inhibitor), respectively, were measured to a single electrical pulse delivered every 30 min. Following treatment with cannabidiol (10-100 µM) or SR141716 (0.003-10 µM), cumulative concentrations of WIN 55,212-2 (0.001-30 µM) were applied followed by a single electrical pulse. The WIN 55,212-2 concentration-contraction curve EC50 values were applied to global regression analysis to determine the pKB. The antagonist potency of cannabidiol at the CB1 receptor in the rat vas deferens bioassay matched the reported receptor binding affinity. Cannabidiol was a competitive antagonist of WIN 55,212-2 with pKB values of 5.90 when ATP was the effector transmitter and 5.29 when it was noradrenaline. Similarly, SR141716 was a competitive antagonist with pKB values of 8.39 for ATP and 7.67 for noradrenaline as the active transmitter. Cannabidiol's low micromolar CB1 antagonist pKB values suggest that at clinical blood levels (1-3 µM) it may act as a CB1 antagonist at prejunctional neuronal sites with more potency when ATP is the effector than for noradrenaline.

Zinc drives vasorelaxation by acting in sensory nerves, endothelium and smooth muscle.

Zinc, an abundant transition metal, serves as a signalling molecule in several biological systems. Zinc transporters are genetically associated with cardiovascular diseases but the function of zinc in vascular tone regulation is unknown. We found that elevating cytoplasmic zinc using ionophores relaxed rat and human isolated blood vessels and caused hyperpolarization of smooth muscle membrane. Furthermore, zinc ionophores lowered blood pressure in anaesthetized rats and increased blood flow without affecting heart rate. Conversely, intracellular zinc chelation induced contraction of selected vessels from rats and humans and depolarized vascular smooth muscle membrane potential. We demonstrate three mechanisms for zinc-induced vasorelaxation: (1) activation of transient receptor potential ankyrin 1 to increase calcitonin gene-related peptide signalling from perivascular sensory nerves; (2) enhancement of cyclooxygenase-sensitive vasodilatory prostanoid signalling in the endothelium; and (3) inhibition of voltage-gated calcium channels in the smooth muscle. These data introduce zinc as a new target for vascular therapeutics.

Developing an Embedded Nursing Service within a Homeless Shelter: Client's Perspectives.

This phenomenological case study of a newly developed nursing service, embedded within a homeless shelter in the South East of England, uses semi-structured to elicit experiences and perceptions of clients within the service. Participants (n = 6) were interviewed using a semi-structured approach and identified three broad themes: impact of previous healthcare experiences, benefits of embedding healthcare within the shelter, and future service development. The study illuminates the diversity and complexity of healthcare needs of homeless people, as well as offers a unique insight into the service user's perception of the service.

Cannabidiol selectively inhibits the contraction of rat small resistance arteries: Possible role for CGRP and voltage-gated calcium channels.

The pharmacology of cannabidiol, the non-psychoactive major component of Cannabis sativa, is of growing interest as it becomes more widely prescribed. This study aimed to examine the effects of cannabidiol on a wide range of contractile agents in rat small resistance arteries, in comparison with large arteries, and to explore its mechanism of action. The vascular actions of cannabidiol were also contrasted with effects on the contractions of bronchial, urogenital, cardiac and skeletal muscles. Isolated small or large arteries were incubated with cannabidiol (0.3-3 µM) or vehicle and concentration-contraction response curves were completed to various agents, including endothelin-1, arginine vasopressin, methoxamine, 5-HT, α-methyl 5-HT and U46619. In small arteries, the effects of cannabidiol were tested in the presence of antagonists of CB1 or CB2 receptors, calcitonin gene-related peptide (CGRP), nitric oxide synthase, cyclooxygenase, PPARγ or a combination. The role of L-type voltage-operated calcium channels was also assessed. Cannabidiol 1-3 µM significantly inhibited the contraction of small resistance arteries to all tested agents through a combination of mechanisms that include CGRP and L-type calcium channels. However, large arteries were insensitive to cannabidiol. Cannabidiol (10-100 µM) was largely without effect in bronchi, atria and hemidiaphragm, but 100 µM attenuated maximum contractions in vasa deferentia. Cannabidiol's effects in the clinical range (1-3 µM) appear to be specific to small resistance arteries. This high sensitivity of the resistance arterial circulation to cannabidiol may offer a therapeutic opportunity in peripheral vascular disease that excludes off-target sites such as the heart and non-vascular smooth muscle.

The ß2-adrenoceptor agonist bronchodilators terbutaline and orciprenaline are also weak α1-adrenoceptor antagonists.

Recently, the ß2-adrenoceptor agonist terbutaline was shown to have α1-adrenolytic activity in mouse isolated pulmonary arteries in vitro and to lower pulmonary artery pressure in anaesthetised mice. The aim of our study was to determine the α1-adrenoceptor antagonist activity of terbutaline and its structurally close resorcinol, orciprenaline, in rat isolated small mesenteric arteries set up for myography. Their α1-adrenoceptor antagonist potency was then compared with their potency as ß2-adrenoceptor agonists. Concentration-response curves to methoxamine were competitively antagonised by terbutaline (30-300 µM) or orciprenaline (30-300 µM) with a pKB of 4.70 ± 0.09 or 4.79 ± 0.17, respectively. Both terbutaline and orciprenaline fulfilled the criteria for simple, silent competitive antagonism. Terbutaline (30-300 µM) had no effect on endothelin-1 concentration-contraction curves. Our findings suggest that after oral dosing of terbutaline, the maximum plasma levels would NOT reach levels to show α1-adrenoceptor antagonist activity. In conclusion, our work has provided additional quantitative evidence that terbutaline and orciprenaline are weak competitive α1-adrenoceptor antagonists, but this additional property is probably not therapeutically important in the clinical treatment of asthma or pulmonary artery hypertension with these more potent ß2-adrenoceptor agonists.

Estimation of the vascular resistance amplifier in the renal vascular bed in conscious hypertensive rabbits: comparison with the total peripheral vasculature.

OBJECTIVES: The vascular amplifier in hypertension is a result of structural changes in resistance arteries. We estimated the vascular amplifier hypertensive:normotensive (H:N) ratio in the renal bed compared with the total peripheral bed in conscious rabbits during infusion of vasoconstrictor and vasodilator stimuli. METHODS: Rabbits were subjected to bilateral renal cellophane wrap or sham operation. A perivascular ultrasonic flow probe was implanted on the left renal artery to measure renal blood flow. A catheter was inserted into the thoracic aorta for agonist administration. Blood pressure, heart rate and renal blood flow were measured on three separate days in conscious rabbits with intact effectors, ganglionic block or neurohumoral block. Dose-response curves were constructed to intra-arterial infusion of noradrenaline, angiotensin II, adenosine and acetylcholine. RESULTS: Resting renal vascular resistance in hypertensive rabbits was markedly decreased by ganglionic block and further by neurohumoral block. With effectors intact, ganglionic block or neurohumoral block, the H:N ratio for renal vascular resistance was 2.32, 1.72 or 1.72, respectively. The ratio was generally maintained during the infusion of constrictor and dilator drugs although distortions occurred at higher concentrations of constrictor or dilator drugs. CONCLUSIONS: Estimation of the renal resistance amplifier in renal wrap hypertension with neurohumoral block accords with our earlier estimates of the total peripheral resistance amplifier (1.79). This vascular resistance amplifier is consistent with a decrease in internal radius through structural remodelling in the renal vascular bed as is reflected in the total arterial circulation in hypertension.

Clinical outcomes of self-expandable vs. balloon-expandable TAVI for severe aortic stenosis.

Background: Transcatheter aortic valve implantation (TAVI) is an established therapy for patients with severe aortic stenosis (AS). There is limited data exploring differences in outcomes post-TAVI SEV vs. BEV. This study compared procedural success and 30-d clinical outcomes self-expandable valves (SEV), vs. balloon-expandable valves (BEV) for patients with severe AS.Methods: Retrospective analysis was undertaken of patients receiving TAVI at St Vincent's Hospital, Melbourne between August 2009 and May 2018. The primary endpoints included procedural success, clinical outcomes and complication rates at 30-d.Results: Out of 151 patients undergoing TAVI, 70 received (46.3%) SEV (Medtronic CoreValve & Evolut-R) and 81 (53.6%) BEV (Edwards SAPIEN-XT & S3). The mean Society of Thoracic Surgery (STS) risk score did not differ between the groups, SEV (83.6 ± 4.9 years, STS 4.4 ± 3.8) compared to BEV (82.3 ± 5.8 years, STS 4.9 ± 4.9). Procedural success was similar SEV 67 (95.7%) vs. BEV 78 (96.3%). Rates of ≥ moderate paravalvular aortic regurgitation (PAR) at 30-d were significantly higher in SEV compared to BEV (6.7 vs. 0.0%; p = .02). SEV patients had higher rates of pacemaker insertion (36.4 vs. 9.5%; p = .001) and stroke rates (12.4 vs. 1.4%; p = .04) compared to BEV patients. The difference in 30-d mortality between the two groups was similar (SEV 4.6% vs. BEV 1.3%; p = .23).Conclusions: This real-world retrospective analysis demonstrates higher rates of ≥ moderate PAR, stroke and pacemaker insertion with SEV compared to BEV at 30 d post-TAVI for severe symptomatic AS.

The effects of varying Mg2+ ion concentrations on contractions to the cotransmitters ATP and noradrenaline in the rat vas deferens.

The vas deferens responds to a single electrical pulse with a biphasic contraction caused by cotransmitters ATP and noradrenaline. Removing Mg2+ (normally 1.2 mM) from the physiological salt solution (PSS) enhances the contraction. This study aimed to determine the effect of Mg2+ concentration on nerve cotransmitter-mediated contractions. Rat vasa deferentia were sequentially bathed in increasing (0, 1.2, 3 mM) or decreasing (3, 1.2, 0 mM) Mg2+ concentrations. At each concentration a single field pulse was applied, and the biphasic contraction recorded. Contractions to exogenous noradrenaline 10 µM and ATP 100 µM were also determined. The biphasic nerve-mediated contraction was elicited by ATP and noradrenaline as NF449 (10 µM) and prazosin (100 nM) completely prevented the respective peaks. Taking the contractions in normal PSS (Mg2+ 1.2 mM) as 100%, lowering Mg2+ to 0 mM enhanced the ATP peak to 170 ±â€¯7% and raising Mg2+ to 3 mM decreased it to 39 ±â€¯3%; the noradrenaline peak was not affected by lowering Mg2+ to 0 mM (97 ±â€¯3%) but was decreased to 63 ±â€¯4% in high Mg2+ (3 mM). Contractions to exogenous ATP, but not noradrenaline, were increased in Mg2+ 0 mM and both were inhibited with Mg2+ 3 mM. Changing Mg2+ concentration affects the contractions elicited by the cotransmitters ATP and noradrenaline. The greatest effects were to potentiate the contraction to ATP in Mg2+ 0 mM and to inhibit the contraction to both ATP and noradrenaline in high Mg2+. Future publications should clearly justify any decision to vary the magnesium concentration from normal (1.2 mM) values.

Role of endothelin-1 clearance in the haemodynamic responses to endothelin-1 in the pulmonary and hindquarter vasculature of anaesthetised rats.

In the pulmonary vasculature there is clearance of endothelin-1 from the circulation mediated by endothelin ETB receptors. This study explored the haemodynamic effects of endothelin-1 and its clearance in the pulmonary and hindquarter vasculature in anaesthetised rats. Carotid and pulmonary artery pressures and pulmonary and hindquarter blood flows were measured. In each rat, a single endothelin-1 or sarafotoxin S6C cumulative dose-response curve was generated with or without antagonist pretreatment (i.v.). Endothelin-1 caused an acute fall in MAP and rise in hindquarter vascular conductance (HVC) followed by a marked increase in MAP at 5 min with falls in HVC and pulmonary vascular conductance (PVC). Bosentan (10, 20 & 30 mg/kg) pretreatment caused dose-dependent inhibition of the MAP increase as well as PVC and HVC decreases to endothelin-1. Similarly, macitentan (30 mg/kg) or ambrisentan (10 mg/kg) caused significant block of responses to endothelin-1. Sarafotoxin S6C caused acute falls in MAP and increases in HVC and then small falls in PVC and HVC, all prevented by pretreatment with ETB antagonist BQ788 (1 mg/kg). Pretreatment with BQ788 enhanced endothelin-1 potency by 2.5-fold in PVC and 2.4-fold in HVC. With BQ788 and bosentan, the fall in HVC response was completely blocked, but there were residual MAP rises and PVC falls at the highest endothelin-1 dose. Our work confirms the role of ETB receptors in the pulmonary vasculature that decrease the circulating levels of endothelin-1. This has important consequences in selecting an appropriate ETA and ETB dual receptor antagonist to effectively block endothelin-1-mediated pulmonary vasoconstriction.

Transcatheter aortic valve implantation for severe aortic stenosis in the Australian regional population.

OBJECTIVE: To compare clinical and functional outcomes of regional and urban patients after transcatheter aortic valve implantation for severe aortic stenosis. METHODS: Data were collected at patient follow-up post-transcatheter aortic valve implantation at 30 days and 12 months. Patients were stratified by residential postcodes into remoteness areas using the Australian Statistical Geography Standard. DESIGN: Retrospective cohort study. SETTING: Single-centre tertiary referral hospital. PARTICIPANTS: Patients undergoing transcatheter aortic valve implantation (n = 142) from 2009 to 2018 were analysed, with 77 patients (54.2%) residing in regional Victoria and New South Wales. MAIN OUTCOME MEASURES: Procedural success, adverse event rates, readmission rates, mortality rates, loss to follow-up and functional improvement. RESULTS: Patients residing in regional areas had a lower mean age (81.8 vs 83.7 years) and proportion of Stage 4 or 5 chronic kidney disease (1.3% vs 9.2%), compared with urban patients. Procedural characteristics and immediate post-procedural outcomes were similar between both groups. There was no statistically significant difference in mortality, readmission rates or loss to follow-up between the two cohorts. Regional patients demonstrated poorer rates of functional improvement at 30 days (50.7% vs 67.7%); however, this difference was not sustained at 12 months (79.2% vs 71.0%). Frailty was demonstrated to be an independent predictor of poor 30-day functional improvement. CONCLUSION: Regional patients treated with transcatheter aortic valve implantation for severe aortic stenosis have non-inferior 30-day and 12-month outcomes, when compared with urban patients. Frailty is a predictor of poor functional improvement post-transcatheter aortic valve implantation.

Outcomes of incidental findings on multi-detector computed tomography for transcatheter aortic valve implantation assessment: A single-centre study and review of the literature.

INTRODUCTION: Patients with severe aortic stenosis (AS) require multi-detector computed tomography (MDCT) when considered for transcatheter aortic valve implantation (TAVI). Incidental findings on MDCT are common given the age group and region imaged. Our aim was to evaluate the frequency and outcome of incidental findings (IF) identified on MDCT and the impact on survival. METHODS: This single-centre analysis retrospectively reviewed severe AS patients who underwent MDCT during TAVI workup. MDCT reports were reviewed for any IF and defined into three categories: IF of no relevant clinical significance (IF-NoCS), IF of non-immediate clinical significance (IF-NICS) and IF of immediate clinical significance (IF-ICS). Demographics, follow-up of IF and survival were calculated from MDCT date. RESULTS: Two hundred and sixty-five patients underwent MDCT for TAVI suitability (mean age 83 ± 6 years, 52% male). The majority proceeded to TAVI (65%). Renal lesions (25%) and lung nodules (18%) were the most common IF. Fifty-nine patients (22%) had IF-NICS; 39% (23/59) were benign, 59% were not further investigated and one patient had suspected lung cancer. Six patients (2.3%) had IF-ICS and all were diagnosed with lung cancer. During a median follow-up of 272 days, there was no survival difference between patients with IF-ICS or IF-NICS versus patients without IF or IF-NoCS in the overall cohort (P = 0.44) or in TAVI patients (P = 0.88). CONCLUSION: Incidental findings on MDCT are common with one-quarter having IF-ICS or IF-NCIS. Most patients with IF-NICS did not undergo further investigation. Standardized reporting of MDCT may assist in clarifying the need for further investigation which will in turn influence decision and timing to proceed with TAVI.

UBC9 Mutant Reveals the Impact of Protein Dynamics on Substrate Selectivity and SUMO Chain Linkages.

SUMO, a conserved ubiquitin-like protein, is conjugated to a multitude of cellular proteins to maintain genomic integrity and resist genotoxic stress. Studies of the SUMO E2 conjugating enzyme mutant, UBC9P123L, suggested that altered substrate specificity enhances cell sensitivity to DNA damaging agents. Using nuclear magnetic resonance chemical shift studies, we confirm that the mutation does not alter the core globular fold of UBC9, while 15N relaxation measurements demonstrate mutant-induced stabilization of distinct chemical states in residues near the active site cysteine and substrate recognition motifs. We further demonstrate that the P123L substitution induces a switch from the preferential addition of SUMO to lysine residues in unstructured sites to acceptor lysines embedded in secondary structures, thereby also inducing alterations in SUMO chain linkages. Our results provide new insights regarding the impact that structural dynamics of UBC9 have on substrate selection and specifically SUMO chain formation. These findings highlight the potential contribution of nonconsensus SUMO targets and/or alternative SUMO chain linkages on DNA damage response and chemotherapeutic sensitivity.

Enhanced psychological care in cardiac rehabilitation services for patients with new-onset depression: the CADENCE feasibility study and pilot RCT.

BACKGROUND: Around 19% of people screened by UK cardiac rehabilitation programmes report having moderate or severe symptoms of depression. These individuals are at an increased risk of cardiac mortality and morbidity, reduced quality of life and increased use of health resources compared with their non-depressed counterparts. Maximising psychological health is a goal of cardiac rehabilitation, but psychological care is patchy. OBJECTIVE(S): To examine the feasibility and acceptability of embedding enhanced psychological care (EPC) within cardiac rehabilitation, we tested the feasibility of developing/implementing EPC and documented the key uncertainties associated with undertaking a definitive evaluation. DESIGN: A two-stage multimethods study; a feasibility study and a qualitative evaluation, followed by an external pilot cluster randomised controlled trial (RCT) with a nested qualitative study. SETTING: UK comprehensive cardiac rehabilitation teams. PARTICIPANTS: Adults eligible for cardiac rehabilitation following an acute coronary syndrome with new-onset depressive symptoms on initial nurse assessment. Patients who had received treatment for depression in the preceding 6 months were excluded. INTERVENTIONS: The EPC intervention comprised nurse-led mental health-care co-ordination and behavioural activation within cardiac rehabilitation. The comparator was usual cardiac rehabilitation care. MAIN OUTCOME MEASURES: Measures at baseline, and at the 5- (feasibility and pilot) and 8-month follow-ups (pilot only). Process measures related to cardiac team and patient recruitment, and participant retention. Outcomes included depressive symptoms, cardiac mortality and morbidity, anxiety, health-related quality of life and service resource use. Interviews explored participant and nurses' views and experiences. RESULTS: Between September 2014 and May 2015, five nurses from four teams recruited participants into the feasibility study. Of the 203 patients screened, 30 were eligible and nine took part (the target was 20 participants). At interview, participants and nurses gave valuable insights into the EPC intervention design and delivery. Although acceptable, the EPC delivery was challenging for nurses (e.g. the ability to allocate sufficient time within existing workloads) and the intervention was modified accordingly. Between December 2014 and February 2015, 8 out of 20 teams approached agreed to participate in the pilot RCT [five were randomised to the EPC arm and three were randomised to the usual-care (UC) arm]. Of the 614 patients screened, 55 were eligible and 29 took part (the target was 43 participants). At baseline, the trial arms were well matched for sex and ethnicity, although the EPC arm participants were younger, from more deprived areas and had higher depression scores than the UC participants. A total of 27 out of 29 participants were followed up at 5 months. Interviews with 18 participants (12 in the EPC arm and six in the UC arm) and seven nurses who delivered EPC identified that both groups acknowledged the importance of receiving psychological support embedded within routine cardiac rehabilitation. For those experiencing/delivering EPC, the intervention was broadly acceptable, albeit challenging to deliver within existing care. LIMITATIONS: Both the feasibility and the pilot studies encountered significant challenges in recruiting patients, which limited the power of the pilot study analyses. CONCLUSIONS: Cardiac rehabilitation nurses can be trained to deliver EPC. Although valued by both patients and nurses, organisational and workload constraints were significant barriers to implementation in participating teams, suggesting that future research may require a modified approach to intervention delivery within current service arrangements. We obtained important data informing definitive research regarding participant recruitment and retention, and optimal methods of data collection. FUTURE RESEARCH: Consideration should be given to the delivery of EPC by dedicated mental health practitioners, working closely with cardiac rehabilitation services. TRIAL REGISTRATION: Current Controlled Trials ISRCTN34701576. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 30. See the NIHR Journals Library website for further project information.

Distortion of KB estimates of endothelin-1 ETA and ETB receptor antagonists in pulmonary arteries: Possible role of an endothelin-1 clearance mechanism.

Dual endothelin ETA and ETB receptor antagonists are approved therapy for pulmonary artery hypertension (PAH). We hypothesized that ETB receptor-mediated clearance of endothelin-1 at specific vascular sites may compromise this targeted therapy. Concentration-response curves (CRC) to endothelin-1 or the ETB agonist sarafotoxin S6c were constructed, with endothelin receptor antagonists, in various rat and mouse isolated arteries using wire myography or in rat isolated trachea. In rat small mesenteric arteries, bosentan displaced endothelin-1 CRC competitively indicative of ETA receptor antagonism. In rat small pulmonary arteries, bosentan 10 µmol L-1 left-shifted the endothelin-1 CRC, demonstrating potentiation consistent with antagonism of an ETB receptor-mediated endothelin-1 clearance mechanism. Removal of endothelium or L-NAME did not alter the EC50 or Emax of endothelin-1 nor increase the antagonism by BQ788. In the presence of BQ788 and L-NAME, bosentan displayed ETA receptor antagonism. In rat trachea (ETB ), bosentan was a competitive ETB antagonist against endothelin-1 or sarafotoxin S6c. Modeling showed the importance of dual receptor antagonism where the potency ratio of ETA to ETB antagonism is close to unity. In conclusion, the rat pulmonary artery is an example of a special vascular bed where the resistance to antagonism of endothelin-1 constriction by ET dual antagonists, such as bosentan or the ETB antagonist BQ788, is possibly due to the competition of potentiation of endothelin-1 by blockade of ETB -mediated endothelin-1 clearance located on smooth muscle and antagonism of ETA - and ETB -mediated contraction. This conclusion may have direct application for the efficacy of endothelin-1 antagonists for treating PAH.