Combination of carvedilol with variceal band ligation in prevention of first variceal bleed in Child-Turcotte-Pugh B and C cirrhosis with high-risk oesophageal varices: the 'CAVARLY TRIAL'.

OBJECTIVES: Beta-blockers and endoscopic variceal band ligation (VBL) have been preferred therapies for primary prophylaxis of variceal bleeding. However, the choice of therapy in patients with advanced liver disease with high-risk varices is not clear. A comparison of these therapies alone or in combination to prevent the first variceal bleed in advanced cirrhosis patients was carried out. DESIGN: 330 Child-Turcotte-Pugh (CTP) B and C cirrhosis patients, with 'high-risk' varices were prospectively enrolled (n=110 per group) to receive carvedilol (group A), VBL (group B) or combination (group C). Primary endpoint was reduction in the incidence of first variceal bleed at 12 months. The secondary endpoints included overall mortality, bleed-related mortality, new-onset decompensation, change in hepatic vein pressure gradient (HVPG) and treatment-related adverse events. RESULTS: The patients were predominantly males (85.2%), aged 51.4±10.5 years with CTP score of 8.87±1.24, MELD score 15.17±3.35 and HVPG-16.96±3.57 mm Hg. The overall incidence of variceal bleed was 23.8% (n=78) at 1 year. Intention-to-treat analysis showed that the combination arm (group C) significantly reduced the incidence of first variceal bleed by 62.9% as compared with group B (HR 0.37, 95% CI 0.192 to 0.716, p<0.003) and by 69.3% as compared with group A (HR 0.31, 95% CI 0.163 to 0.578, <0.001). The overall mortality was 13.6% (45/330). The 1-year mortality in group C was lowest among the three groups (A, B, C=20%, 14.5%, 6.3%, p=0.012). Reduction in HVPG (20.8% vs 25.1%, p=0.54) and the rate of non-response to carvedilol (53.4% vs 41.25%, p=0.154) were not different between group A and C patients. The incidence of new-onset ascites, spontaneous bacterial peritonitis, shock, and acute kidney injury and postbleed organ failure was also comparable between the groups. CONCLUSION: In CTP B and C cirrhosis patients with high-risk varices, combination of carvedilol and VBL is more effective than either therapy alone, for primary prevention of variceal bleeding. TRIAL REGISTRATION NUMBER: NCT03069339.

Metabolomics of repetitive myocardial stunning in chronic multivessel coronary artery stenosis: Effect of non-selective and selective ß1-receptor blockers.

Chronic coronary artery stenosis can lead to regional myocardial dysfunction in the absence of myocardial infarction by repetitive stunning, hibernation or both. The molecular mechanisms underlying repetitive stunning-associated myocardial dysfunction are not clear. We used non-targeted metabolomics to elucidate responses to chronically stunned myocardium in a canine model with and without ß-adrenergic blockade treatment. After development of left ventricular systolic dysfunction induced by ameroid constrictors on the coronary arteries, animals were randomized to 3 months of placebo, metoprolol or carvedilol. We compared these two ß-blockers with their different ß-adrenergic selectivities on myocardial function, perfusion and metabolic pathways involved in tissue undergoing chronic stunning. Control animals underwent sham surgery. Dysfunction in stunned myocardium was associated with reduced fatty acid oxidation and enhanced ketogenic amino acid metabolism, together with alterations in mitochondrial membrane phospholipid composition. These changes were consistent with impaired mitochondrial function and were linked to reduced nitric oxide and peroxisome proliferator-activated receptor signalling, resulting in a decline in adenosine monophosphate-activated protein kinase. Mitochondrial changes were ameliorated by carvedilol more than metoprolol, and improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. In summary, repetitive myocardial stunning commonly seen in chronic multivessel coronary artery disease is associated with adverse metabolic remodelling linked to mitochondrial dysfunction and specific signalling pathways. These changes are reversed by ß-blockers, with the non-selective inhibitor having a more favourable impact. This is the first investigation to demonstrate that ß-blockade-associated improvement of ventricular function in chronic myocardial stunning is associated with restoration of mitochondrial function. KEY POINTS: The mechanisms responsible for the metabolic changes associated with repetitive myocardial stunning seen in chronic multivessel coronary artery disease have not been fully investigated. In a canine model of repetitive myocardial stunning, we showed that carvedilol, a non-selective ß-receptor blocker, ameliorated adverse metabolic remodelling compared to metoprolol, a selective ß1-receptor blocker, by improving nitric oxide synthase and adenosine monophosphate protein kinase function, enhancing calcium/calmodulin-dependent protein kinase, probably increasing hydrogen sulphide, and suppressing cyclic-adenosine monophosphate signalling. Mitochondrial fatty acid oxidation alterations were ameliorated by carvedilol to a larger extent than metoprolol; this improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. Both ß-blockers improved the cardiac energy imbalance by reducing metabolites in ketogenic amino acid and nucleotide metabolism. These results elucidated why metabolic remodelling with carvedilol is preferable to metoprolol when treating chronic ischaemic left ventricular systolic dysfunction caused by repetitive myocardial stunning.

The ß-Blocker Carvedilol and Related Aryloxypropanolamines Promote ERK1/2 Phosphorylation in HEK293 Cells with K A Values Distinct From Their Equilibrium Dissociation Constants as ß 2-Adrenoceptor Antagonists: Evidence for Functional Affinity.

The determination of affinity by using functional assays is important in drug discovery because it provides a more relevant estimate of the strength of interaction of a ligand to its cognate receptor than radioligand binding. However, empirical evidence for so-called, "functional affinity" is limited. Herein, we determined whether the affinity of carvedilol, a ß-adrenoceptor antagonist used to treat heart failure that also promotes extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation, differed between these two pharmacological activities. Four structurally related ß-adrenoceptor antagonists (alprenolol, carazolol, pindolol, propranolol) that also activated ERK1/2 were included as comparators to enhance our understanding of how these drugs work in the clinical setting. In HEK293 cells stably expressing the human ß 2-adrenoceptor carvedilol and related aryloxypropanolamines were partial agonists of ERK1/2 phosphorylation with potencies ([A]50s) that were lower than their equilibrium dissociation constants (K Bs) as ß 2-adrenoceptor antagonists. As the [A]50 of a partial agonist is a good approximation of its K B, then these data indicated that the affinities of carvedilol and related ligands for these two activities were distinct. Moreover, there was a significant negative rank order correlation between the [A]50 of each ligand to activate ERK1/2 and their intrinsic activities (i.e., as intrinsic activity for ERK1/2 phosphorylation increased, so did affinity). Genome editing revealed that the transducer that coupled the ß 2-adrenoceptor to ERK1/2 phosphorylation in response to carvedilol and other ß 2-adrenoceptor antagonists was Gαs. Collectively, these data support the concept of "functional affinity" and indicate that the ability of the ß 2-adrenoceptor to recruit Gαs may influence the affinity of the activating ligand. SIGNIFICANCE STATEMENT: In HEK293 cells overexpressing the human ß2-adrenoceptor carvedilol and four related aryloxypropanolamines behaved as ß2-adrenoceptor antagonists and partial agonists of ERK1/2 phosphorylation with rank orders of affinity that were distinct. These data imply that carvedilol and other ß-blockers can stabilize the ß2-adrenoceptor in different affinity conformations that are revealed when functionally distinct responses are measured. This is the basis for the pharmacological concept of "functional affinity."

Sentinel lymph node biopsy for breast cancer during pregnancy: A comprehensive update.

BACKGROUND: Pregnant patients diagnosed with breast cancer (PrBC) may receive substantially different treatments compared to general population, considering that certain treatment options cannot be applied during pregnancy due to their potential harmful effects to the foetus. Regarding the use of sentinel lymph node biopsy (SLNB) in pregnant patients, potential concerns include foetal harm from radiation exposure, possible teratogenic effects of blue dyes and maternal anaphylaxis to isosulfan. OBJECTIVE: The main objective of the present systematic review is to summarize and present current knowledge and up-to-date evidence about the safety and efficacy of SLNB in PABC. METHODS: MEDLINE, Google Scholar and UpToDate databases were searched up to 22 January 2023. Articles studying the safety and effectiveness of SLNB in patients for PrBC were eligible for inclusion in the present review. RESULTS: In total, 63 articles that met the inclusion criteria were included in this study. Forty-seven articles were strongly in favour of performing SLNB in PABC, 4 articles were partially in favour, 10 articles were strongly against and 2 articles were partially against performing SLNB in PABC. Sub-categorization based on type of study showed that the majority of studies in favour were of higher level of evidence than those against. Furthermore, there were overall 12 studies reporting on outcomes. There were overall 382 women with PrBC that underwent SLNB. Full data were reported for 237 cases. Overall live birth rate was 95.8%, while overall neonatal complication rate was 3.4%. No case of maternal side effects or anaphylactic reaction, maternal death, stillbirth and neonatal death was reported (0%). CONCLUSIONS: Sentinel lymph node biopsy seems to be safe and effective technique for breast cancer during pregnancy.

Survival in pregnancy-associated breast cancer patients compared to non-pregnant controls.

BACKGROUND: Pregnancy-associated breast cancer (PABC) is a rare entity whose prognosis has previously been studied and is subject to controversy. METHODS: Survival of patients with PABC diagnosed between 2009 and 2021 with breast cancer during pregnancy or until 1 year after childbirth was compared with non-pregnant patients with breast cancer from the same period at La Paz University Hospital. Cox proportional hazards regression was used to compare disease-free (DFS) and overall (OS) survival between the groups, adjusting for grade and pathologic stage. RESULTS: Among the 89 included patients with breast cancer, 34 were diagnosed during pregnancy, and 55 were not pregnant. The pregnant patients were more likely to have grade 3 tumors (61.3% vs 37%, p = 0.023) and an advanced stage (pathologic stage III-IV: 44.1% vs 17.6%, p = 0.008). Median follow-up was 47 months for the pregnant group and 46 months for the control group. After adjustments for tumor grade and pathologic stage, OS was comparable between the groups (HR 2.03; 95% CI 0.61 to 6.79; P = 0.25). CONCLUSIONS: The outcome of women diagnosed with PABC is comparable to young non-pregnant controls. However, it should be taken into account that PABC has a more aggressive phenotype.

Enteroids to Study Pediatric Intestinal Drug Transport.

Intestinal maturational changes after birth affect the pharmacokinetics (PK) of drugs, having major implications for drug safety and efficacy. However, little is known about ontogeny-related PK patterns in the intestine. To explore the accuracy of human enteroid monolayers for studying drug transport in the pediatric intestine, we compared the drug transporter functionality and expression in enteroid monolayers and tissue from pediatrics and adults. Enteroid monolayers were cultured of 14 pediatric [median (range) age: 44 weeks (2 days-13 years)] and 5 adult donors, in which bidirectional drug transport experiments were performed. In parallel, we performed similar experiments with tissue explants in Ussing chamber using 11 pediatric [median (range) age: 54 weeks (15 weeks-10 years)] and 6 adult tissues. Enalaprilat, propranolol, talinolol, and rosuvastatin were used to test paracellular, transcellular, and transporter-mediated efflux by P-gp and breast cancer resistance protein (BCRP), respectively. In addition, we compared the expression patterns of ADME-related genes in pediatric and adult enteroid monolayers with tissues using RNA sequencing. Efflux transport by P-gp and BCRP was comparable between the enteroids and tissue. Efflux ratios (ERs) of talinolol and rosuvastatin by P-gp and BCRP, respectively, were higher in enteroid monolayers compared to Ussing chamber, likely caused by experimental differences in model setup and cellular layers present. Explorative statistics on the correlation with age showed trends of increasing ER with age for P-gp in enteroid monolayers; however, it was not significant. In the Ussing chamber setup, lower enalaprilat and propranolol transport was observed with age. Importantly, the RNA sequencing pathway analysis revealed that age-related variation in drug metabolism between neonates and adults was present in both enteroids and intestinal tissue. Age-related differences between 0 and 6 months old and adults were observed in tissue as well as in enteroid monolayers, although to a lesser extent. This study provides the first data for the further development of pediatric enteroids as an in vitro model to study age-related variation in drug transport. Overall, drug transport in enteroids was in line with data obtained from ex vivo tissue (using chamber) experiments. Additionally, pathway analysis showed similar PK-related differences between neonates and adults in both tissue and enteroid monolayers. Given the challenge to elucidate the effect of developmental changes in the pediatric age range in human tissue, intestinal enteroids derived from pediatric patients could provide a versatile experimental platform to study pediatric phenotypes.

Rerouting cardiovascular management following gastric bypass surgery: Dose optimization of carvedilol using population-based analysis.

AIMS: A population-based pharmacokinetic (PK) modeling approach (PopPK) was used to investigate the impact of Roux-en-Y gastric bypass (RYGB) on the PK of (R)- and (S)-carvedilol. We aimed to optimize carvedilol dosing for these patients utilizing a pharmacokinetic/pharmacodynamic (PK/PD) link model. METHODS: PopPK models were developed utilizing data from 52 subjects, including nonobese, obese, and post- RYGB patients who received rac- carvedilol orally. Covariate analysis included anthropometric and laboratory data, history of RYGB surgery, CYP2D6 and CYP3A4 in vivo activity, and relative intestinal abundance of major drug- metabolizing enzymes and transporters. A direct effect inhibitory Emax pharmacodynamic model was linked to the PK model of (S)- carvedilol to simulate the changes in exercise- induced heart rate. RESULTS: A 2-compartmental model with linear elimination and parallel first-order absorptions best described (S)-carvedilol PK. RYGB led to a twofold reduction in relative oral bioavailability compared to nonoperated subjects, along with delayed absorption of both enantiomers. The intestinal ABCC2 mRNA expression increases the time to reach the maximum plasma concentration. The reduced exposure (AUC) of (S)-carvedilol post-RYGB corresponded to a 33% decrease in the predicted area under the effect curve (AUEC) for the 24-hour ß-blocker response. Simulation results suggested that a 50-mg daily dose in post-RYGB patients achieved comparable AUC and AUEC to 25-mg dose in nonoperated subjects. CONCLUSION: Integrated PK/PD modeling indicated that standard dosage regimens for nonoperated subjects do not provide equivalent ß-blocking activity in RYGB patients. This study highlights the importance of personalized dosing strategies to attain desired therapeutic outcomes in this patient cohort.

MRI of the Lactating Breast.

The breasts undergo marked physiologic changes during lactation that can make conventional imaging evaluation with mammography and US challenging. MRI can be a valuable diagnostic aid to differentiate physiologic and benign processes from malignancy in patients who are lactating. In addition, MRI may allow more accurate delineation of disease involvement than does conventional imaging and assists in locoregional staging, screening of the contralateral breast, assessment of response to neoadjuvant chemotherapy, and surgical planning. Although the American College of Radiology recommends against patients undergoing contrast-enhanced MRI during pregnancy because of fetal safety concerns, contrast-enhanced MRI is safe during lactation. As more women delay childbearing, the incidence of pregnancy-associated breast cancer (PABC) and breast cancer in lactating women beyond the 1st year after pregnancy is increasing. Thus, MRI is increasingly being performed in lactating women for diagnostic evaluation and screening of patients at high risk. PABC is associated with a worse prognosis than that of non-PABCs, with delays in diagnosis contributing to an increased likelihood of advanced-stage disease at diagnosis. Familiarity with the MRI features of the lactating breast and the appearance of various pathologic conditions is essential to avoid diagnostic pitfalls and prevent delays in cancer diagnosis and treatment. The authors review clinical indications for breast MRI during lactation, describe characteristic features of the lactating breast at MRI, and compare MRI features of a spectrum of benign and malignant breast abnormalities. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chikarmane in this issue.

Potent drug delivery enhancement of betulinic acid and NVX-207 into equine skin in vitro - a comparison between a novel oxygen flow-assisted transdermal application device and microemulsion gels.

BACKGROUND: Gray horses are predisposed to equine malignant melanoma (EMM) with advancing age. Depending on the tumor's location and size, they can cause severe problems (e.g., defaecation, urination, feeding). A feasible therapy for EMM has not yet been established and surgical excision can be difficult depending on the location of the melanoma. Thus, an effective and safe therapy is needed. Naturally occurring betulinic acid (BA), a pentacyclic triterpene and its synthetic derivate, NVX-207 (3-acetyl-betulinic acid-2-amino-3-hydroxy-2-hydroxymethyl-propanoate) are known for their cytotoxic properties against melanomas and other tumors and have already shown good safety and tolerability in vivo. In this study, BA and NVX-207 were tested for their permeation potential into equine skin in vitro in Franz-type diffusion cell (FDC) experiments after incubation of 5 min, 30 min and 24 h, aiming to use these formulations for prospective in vivo studies as a treatment for early melanoma stages. Potent permeation was defined as reaching or exceeding the half maximal inhibitory concentrations (IC50) of BA or NVX-207 for equine melanoma cells in equine skin samples. The active ingredients were either dissolved in a microemulsion (ME) or in a microemulsion gel (MEG). All of the formulations were transdermally applied but the oil-in-water microemulsion was administered with a novel oxygen flow-assisted (OFA) applicator (DERMADROP TDA). RESULTS: All tested formulations exceeded the IC50 values for equine melanoma cells for BA and NVX-207 in equine skin samples, independently of the incubation time NVX-207 applied with the OFA applicator showed a significant time-dependent accumulation and depot-effect in the skin after 30 min and 24 h (P < 0.05). CONCLUSIONS: All tested substances showed promising results. Additionally, OFA administration showed a significant accumulation of NVX-207 after 30 min and 24 h of incubation. Further in vivo trials with OFA application are recommended.

The role of esmolol in sepsis: a meta-analysis based on randomized controlled trials.

BACKGROUND: Sepsis is associated with a high incidence and mortality and poses a significant challenge to the treatment. Although esmolol has shown promise in sepsis treatment, its efficacy and safety remain contentious. This meta-analysis aims to clarify the role of esmolol in sepsis management. METHODS: PubMed, Embase, Web of Science, Cochrane library, clinicaltrials.gov and the Chinese Clinical Trial Registry were searched and references of relevant reviews and meta-analysis were also screened for appropriate studies. Keywords and free words of 'sepsis', 'esmolol' and 'randomized controlled trials' were used for search. Meta-analysis was performed using RevMan 5.3 software. RESULTS: Fifteen studies involving 1100 patients were included. Compared with the control group, patients receiving esmolol exhibited significantly decreased 28-day mortality (RR, 0.69; 95% CI, 0.60 to 0.81; P < 0.0001), heart rate (HR) (SMD, -1.15; 95% CI, -1.34 to -0.96; P < 0.0001), cardiac troponin I levels (cTnI) (SMD, -0.88; 95% CI, -1.13 to -0.64; P < 0.0001), length of intensive care unit (ICU) stay (SMD, -0.46; 95% CI, -0.62 to -0.3; P < 0.0001) and duration of mechanical ventilation (SMD, -0.28; 95% CI, -0.48 to -0.09; P = 0.004) and significantly increased central venous oxygen saturation (ScvO2) (SMD, 0.66; 95% CI, 0.44 to 0.88; P < 0.0001).While, esmolol had no significant influence on norepinephrine dosage (SMD, 0.08; 95% CI, -0.13 to 0.29; P = 0.46), mean arterial pressure (MAP) (SMD, 0.17; 95% CI, -0.07 to 0.4; P = 0.16), central venous pressure (CVP) (SMD, 0.16; 95% CI, -0.04 to 0.35; P = 0.11) and left ventricular ejection fraction (LVEF) (SMD, 0.21; 95% CI, -2.9 to 0.7; P = 0.41). CONCLUSION: Esmolol reduces 28-day mortality, length of ICU stay and duration of mechanical ventilation in sepsis patients. Furthermore, esmolol improves oxygen metabolism, mitigates myocardial injury and decreases heart rate without significantly affecting hemodynamic parameters. TRIAL REGISTRATION: This study was registered on the PROSPERO website (registration number: CRD42023484884).

Developmental and reproductive toxicity hazard characterization of 2-amino-2-methyl-1-propanol (AMP).

2-Amino-2-methyl-1-propanol (AMP™) is a widely used pH stabilizer in personal care products (PCPs); thus, the safety implications of dermal AMP exposure remain of interest. We have previously reported that exposure to AMP in PCPs when used as intended is not anticipated to result in an increased risk of hepatotoxicity (primarily steatosis and altered phospholipid homeostasis). The current study focuses on AMP in PCP's potential for developmental and reproductive toxicity (DART) in humans, based on data from animal studies. Animal studies suggest that exposure to AMP can result in post-implantation loss. However, such effects occur at maternally toxic doses, posing a challenge for determining appropriate hazard classifications in the context of relevant consumer use scenarios. Our assessment concluded that human exposure to AMP in PCPs is not anticipated to result in DART at non-maternally toxic doses. Further, mode of action (MOA) analysis elucidated the potential biological pathways underlying DART effects observed in high-dose animal studies, such that perturbation of uterine choline synthesis was the most well-supported MOA hypothesis. Downstream uterine effects might reflect choline-dependent changes in epigenetic control of pathways important for implantation maintenance and uterine cell energetics. Since AMP-induced post-implantation loss occurs at doses higher than pathology related to liver toxicity, maintaining AMP exposures from exceeding the onset dose for maternal liver effects will also be protective of DART effects. Furthermore, dermal exposure to AMP expected from the use of PCPs is highly unlikely to result in toxicologically significant systemic AMP concentrations; thus, DART is not anticipated.

Early Intravenous Beta-Blockade with Esmolol in Adults with Severe Traumatic Brain Injury (EBB-TBI): Protocol for a Phase 2a Intervention Design Study.

Traumatic brain injury is a leading cause of death and disability worldwide. Interventions that mitigate secondary brain injury have the potential to improve outcomes for patients and reduce the impact on communities and society. Increased circulating catecholamines are associated with worse outcomes and there are supportive animal data and indications in human studies of benefit from beta-blockade after severe traumatic brain injury. Here, we present the protocol for a dose-finding study using esmolol in adults commenced within 24 h of severe traumatic brain injury. Esmolol has practical advantages and theoretical benefits as a neuroprotective agent in this setting, but these must be balanced against the known risk of secondary injury from hypotension. The aim of this study is to determine a dose schedule for esmolol, using the continual reassessment method, that combines a clinically significant reduction in heart rate as a surrogate for catecholamine drive with maintenance of cerebral perfusion pressure. The maximum tolerated dosing schedule for esmolol can then be tested for patient benefit in subsequent randomized controlled trials.Trial registration ISRCTN, ISRCTN11038397, registered retrospectively 07/01/2021 https://www.isrctn.com/ISRCTN11038397.

Perioperative effects of different hypotensive anesthesia techniques in orthognathic surgery.

BACKGROUND: This study aimed to investigate the effectiveness of combining sevoflurane with remifentanil, esmolol, or nitroglycerin for hypotensive anesthesia and determine the suitable hypotensive anesthesia method for orthognathic surgery. MATERIAL AND METHODS: This retrospective study included 60 patients who underwent orthognathic surgery for developmental malocclusion. They were divided into three groups based on the hypotensive agent preferences: Group 1 (n = 20), sevoflurane and remifentanil; Group 2 (n = 20), sevoflurane and esmolol; Group 3 (n = 20), sevoflurane and nitroglycerin. Bleeding volume, heart rate, systolic, diastolic, and mean arterial blood pressure were recorded at certain times during the perioperative period, including at stages with increased stress levels in the body, such as incision and osteotomy. The patients' blood pressure, analgesic consumption and pain level were recorded in the postoperative period. RESULTS: Bleeding volume, surgery satisfaction related to bleeding, and total operation time did not differ significantly between groups. Intraoperatively, heart rates were significantly higher in Group 3 than in Groups 1 and 2 (p = 0.001). However, hemodynamic stability was similar in Groups 1 and 2. Postoperatively, analgesic consumption, pain levels, and blood pressure dynamics did not differ significantly between groups (p > 0.05). CONCLUSIONS: Based on this study's results, it was concluded that infusing remifentanil, esmolol, or nitroglycerin with sevoflurane during orthognathic surgery successfully achieved the targeted hypotensive anesthesia and can be considered alternative methods. The decision on which method to use should consider the patient's overall health status and additional medical conditions.

Relationship of Inotropic Effects of Stimulation of ß1- and ß2-Adrenergic Receptors of Isolated Myocardial Fragments with Echocardiography Parameters in Coronary Heart Disease.

We studied the relationship of inotropic responses of the isolated myocardium to stimulation of ß1-and ß2-adrenergic receptors (ß-AR) with echocardiography parameters in 28 patients with coronary heart disease (CHD). Myocardial fragments (trabeculae of the right atrial appendage) were obtained during coronary artery bypass surgery. The inotropic response of the trabeculae was assessed in an isometric mode. Stimulation of ß1-and ß2-AR with agonists was performed against the background of preliminary α-AR blockade. In case of preserved ejection fraction, significant inotropic response of the trabeculae (135 (112; 154)% from the initial contraction amplitude) was observed after ß1-AR stimulation, while in reduced ejection fraction, its significant increase was observed after ß1-AR stimulation (126 (112; 170)% from the initial contraction amplitude). In patients with preserved and reduced ejection fraction, the correlations between the inotropic responses of the trabeculae to ß1-and ß2-AR stimulation and echocardiography parameters were different. The revealed differences reflect the degree of cardiac remodeling under condition of the studied pathology.

Kinetics of Strand Displacement Reaction with Acyclic Artificial Nucleic Acids.

Toehold-mediated strand displacement (TMSD) reaction, one of the DNA nanotechnologies, has great potential as s biological programmable platform in the cellular environment. Various artificial nucleic acids have been developed to improve stability and affinity for biological applications. However, the lack of understanding of the kinetics of TMSD reaction among artificial nucleic acids has limited their applications. We herein systematically characterized the kinetics of TMSD reactions with acyclic xeno nucleic acids (XNAs): serinol nucleic acid (SNA), acyclic D-threoninol nucleic acid (D-aTNA), and acyclic L-threoninol nucleic acid (L-aTNA). We found that the strand displacement reactions by D-aTNA and by L-aTNA were highly dependent on temperature. D-aTNA and L-aTNA systems were orthogonal to each other, and chirality of the input can be switched by using SNA as an interface. We also applied TMSD reactions of XNAs to a seesaw gate amplification system which utilizes the orthogonality. This work will contribute to the developments of thermoresponsive and bioorthogonal nucleic acid circuits.

Mechanism of intracellular allosteric ß2AR antagonist revealed by X-ray crystal structure.

G-protein-coupled receptors (GPCRs) pose challenges for drug discovery efforts because of the high degree of structural homology in the orthosteric pocket, particularly for GPCRs within a single subfamily, such as the nine adrenergic receptors. Allosteric ligands may bind to less-conserved regions of these receptors and therefore are more likely to be selective. Unlike orthosteric ligands, which tonically activate or inhibit signalling, allosteric ligands modulate physiologic responses to hormones and neurotransmitters, and may therefore have fewer adverse effects. The majority of GPCR crystal structures published to date were obtained with receptors bound to orthosteric antagonists, and only a few structures bound to allosteric ligands have been reported. Compound 15 (Cmpd-15) is an allosteric modulator of the ß2 adrenergic receptor (ß2AR) that was recently isolated from a DNA-encoded small-molecule library. Orthosteric ß-adrenergic receptor antagonists, known as beta-blockers, are amongst the most prescribed drugs in the world and Cmpd-15 is the first allosteric beta-blocker. Cmpd-15 exhibits negative cooperativity with agonists and positive cooperativity with inverse agonists. Here we present the structure of the ß2AR bound to a polyethylene glycol-carboxylic acid derivative (Cmpd-15PA) of this modulator. Cmpd-15PA binds to a pocket formed primarily by the cytoplasmic ends of transmembrane segments 1, 2, 6 and 7 as well as intracellular loop 1 and helix 8. A comparison of this structure with inactive- and active-state structures of the ß2AR reveals the mechanism by which Cmpd-15 modulates agonist binding affinity and signalling.

Hospital-based health technology assessment of innovative medical devices: insights from a nationwide survey in France.

OBJECTIVES: To better understand the process of hospital acquisition of innovative medical devices (MDs) and the hospital-based health technology assessment (HB-HTA) pathways in France, an in-depth study based on a quantitative approach is needed. The aim of the present study was to assess through a national survey how HB-HTA is currently implemented in French hospitals and to identify its level of formalization. METHODS: A quantitative online survey was conducted among hospitals performing HB-HTA in France, with a focus on the acquisition of innovative MDs for individual use. The survey, conducted between March and June 2022, was developed by a scientific board composed of members of the French-speaking Society for HB-HTA. RESULTS: Sixty-seven out of 131 surveyed hospitals with HB-HTA activities responded, including 29 university hospitals, 24 nonprofit private hospitals, and 14 local hospitals. Sixty-one respondents (91 percent) reported the existence of a process dedicated to evaluating innovative MDs; of these, 16 declared that their hospitals had a formalized unit with HB-HTA activity. These units were more frequently found in larger hospitals with more than 500 inpatient beds (n = 16, p = 0.0160) and in university hospitals (n = 12, p = 0.0158). No hospital reported any collaboration with HAS, the French national HTA agency. CONCLUSION: A diverse range of HB-HTA organizations with different structural levels exist in France for MD procurement linked to the category of hospitals. The study highlights the need for recognition of HB-HTA activity at the regulatory level in France and for direct collaboration between HTA activities performed at local and national levels.

Population Pharmacokinetic-Pharmacodynamic Modeling of Carvedilol to Evaluate the Effect of Cytochrome P450 2D6 Genotype on the Heart Rate Reduction.

BACKGROUND: Carvedilol is a beta-adrenergic receptor antagonist primarily metabolized by cytochromes P450 (CYP) 2D6. This study established a carvedilol population pharmacokinetic (PK)-pharmacodynamic (PD) model to describe the effects of CYP2D6 genetic polymorphisms on the inter-individual variability of PK and PD. METHODS: The PK-PD model was developed from a clinical study conducted on 21 healthy subjects divided into three CYP2D6 phenotype groups, with six subjects in the extensive metabolizer (EM, *1/*1, *1/*2), seven in the intermediate metabolizer-1 (IM-1, *1/*10, *2/*10), and eight in the intermediate metabolizer-2 (IM-2, *10/*10) groups. The PK-PD model was sequentially developed, and the isoproterenol-induced heart rate changes were used to establish the PD model. A direct effect response and inhibitory Emax model were used to develop a carvedilol PK-PD model. RESULTS: The carvedilol PK was well described by a two-compartment model with zero-order absorption, lag time, and first-order elimination. The carvedilol clearance in the CYP2D6*10/*10 group decreased by 32.8% compared with the other groups. The inhibitory concentration of carvedilol estimated from the final PK-PD model was 16.5 ng/mL regardless of the CYP2D6 phenotype. CONCLUSION: The PK-PD model revealed that the CYP2D6 genetic polymorphisms were contributed to the inter-individual variability of carvedilol PK, but not PD.

Indicators of haemodynamic instability and left ventricular function in a porcine model of esmolol induced negative inotropy.

To investigate if the Hypotension Prediction Index was an early indicator of haemodynamic instability in a negative inotropy porcine model, and to assess the correlation of commonly measured indicators of left ventricular systolic function. Eight anaesthetised pigs were volume resuscitated and then underwent an incremental infusion of esmolol hydrochloride (0-3000 mg/hr), following which it was then reduced in a stepwise manner. Full haemodynamic measurements were taken at each stage and measurements of left ventricular systolic function including left ventricular stroke work index, ejection fraction and peripheral dP/dT were obtained. At an infusion rate of 500 mg/hr of esmolol there were no significant changes in any measured variables. At 1000 mg/hr MAP was on average 11 mmHg lower (95% CI 1 to 11 mmHg, p = 0.027) with a mean of 78 mmHg, HPI increased by 33 units (95% CI 4 to 62, p = 0.026) with a mean value of 63. No other parameters showed significant change from baseline values. Subsequent increases in esmolol showed changes in all parameters except SVV, SVR and PA mean. Correlation between dP/dt and LVSWI was 0.85 (95% CI 0.77 to 0.90, p < 0.001), between LVEF and dP/dt 0.39 (95% CI 0.18 to 0.57, p < 0.001), and between LSWI and LVEF 0.41 (95% CI 0.20 to 0.59, p < 0.001). In this model haemodynamic instability induced by negative inotropy was detected by the HPI algorithm prior to any clinically significant change in commonly measured variables. In addition, the peripheral measure of left ventricular contractility dP/dt correlates well with more established measurements of LV systolic function.

Divergent splanchnic sympathetic efferent nerve pathways regulate interleukin-10 and tumour necrosis factor-α responses to endotoxaemia.

The efferent branches of the splanchnic sympathetic nerves that enhance interleukin-10 (IL-10) and suppress tumour necrosis factor-α (TNF) levels in the reflex response to systemic immune challenge were investigated in anaesthetized, ventilated rats. Plasma levels of TNF and IL-10 were measured 90 min after intravenous lipopolysaccharide (LPS, 60 µg/kg). Splanchnic nerve section, ganglionic blockade with pentolinium tartrate or ß2 adrenoreceptor antagonism with ICI 118551 all blocked IL-10 responses. Restoring plasma adrenaline after splanchnic denervation rescued IL-10 responses. TNF responses were disinhibited by splanchnic denervation or pentolinium treatment, but not by ICI 118551. Splanchnic nerve branches were cut individually or in combination in vagotomized rats, ruling out any vagal influence on results. Distal splanchnic denervation, sparing the adrenal nerves, disinhibited TNF but did not reduce IL-10 responses. Selective adrenal denervation depressed IL-10 but did not disinhibit TNF responses. Selective denervation of either spleen or liver did not affect IL-10 or TNF responses, but combined splenic and adrenal denervation did so. Finally, combined section of the cervical and lumbar sympathetic nerves did not affect cytokine responses to LPS. Together, these results show that the endogenous anti-inflammatory reflex is mediated by sympathetic efferent fibres that run in the splanchnic, but not other sympathetic nerves, nor the vagus. Within the splanchnic nerves, divergent pathways control these two cytokine responses: neurally driven adrenaline, acting via ß2 adrenoreceptors, regulates IL-10, while TNF is restrained by sympathetic nerves to abdominal organs including the spleen, where non-ß2 adrenoreceptor mechanisms are dominant. KEY POINTS: An endogenous neural reflex, mediated by the splanchnic, but not other sympathetic nerves, moderates the cytokine response to systemic inflammatory challenge. This reflex suppresses the pro-inflammatory cytokine tumour necrosis factor-α (TNF), while enhancing levels of the anti-inflammatory cytokine interleukin-10 (IL-10). The reflex enhancement of IL-10 depends on the splanchnic nerve supply to the adrenal gland and on ß2 adrenoreceptors, consistent with mediation by circulating adrenaline. After splanchnic nerve section it can be rescued by restoring circulating adrenaline. The reflex suppression of TNF depends on splanchnic nerve branches that innervate abdominal tissues including, but not restricted to, spleen: it is not blocked by adrenal denervation or ß2 adrenoreceptor antagonism. Distinct sympathetic efferent pathways are thus responsible for pro- and anti-inflammatory cytokine components of the reflex regulating inflammation.