Beta-adrenergic Agonist Research Articles

The Impact of Twice-Daily Indacaterol/Glycopyrrolate on the Components of Health-Related Quality of Life and Dyspnea in Patients with Moderate-to-Severe Chronic Obstructive Pulmonary Disease.

Chronic cough, dyspnea, and excessive sputum production, the characteristic symptoms of chronic obstructive pulmonary disease (COPD), can negatively affect patients' health-related quality of life (HRQoL). The fixed-dose combination of a long-acting beta2-adrenergic agonist and a long-acting muscarinic antagonist (LABA/LAMA) have been shown to improve HRQoL and COPD symptoms as measured by the St George's Respiratory Questionnaire (SGRQ) and the Transition Dyspnea Index (TDI) total scores. However, the impact of a LABA/LAMA on the individual components of HRQoL and dyspnea with daily activities is unknown. Secondary analysis of pooled data from 2 replicate, phase 3, 12-week, randomized, placebo, and active-controlled trials of twice-daily indacaterol/glycopyrrolate (IND/GLY) were analyzed. Change from baseline in HRQoL and dyspnea was measured by SGRQ and TDI, respectively. Total and component scores were evaluated using linear mixed models. Logistic regression was used to analyze the proportion of patients achieving minimum clinically important difference. Study outcomes were further explored in patient subgroups. A total of 2038 patients from FLIGHT1/FLIGHT2 studies were evaluated. IND/GLY significantly improved SGRQ component scores (symptoms [-7.3], activity [-3.6], and impacts [-5.0]); all P < 0.001 compared with placebo. IND/GLY also significantly improved symptoms scores compared with IND and GLY (-3.5 and -3.7, respectively; both P < 0.001). Patients treated with IND/GLY also had significant improvements in TDI component scores compared with placebo: functional impairment (0.48), magnitude of task (0.61), and magnitude of effort (0.54); all P < 0.001. All component scores were significantly higher for IND/GLY compared with IND and GLY (P ≤ 0.002 for all). Twice-daily IND/GLY significantly improved total scores as well as components of HRQoL and dyspnea in patients with COPD. These data demonstrate multiple clinical benefits of LABA/LAMA maintenance therapy in the COPD population. ClinicalTrials.gov: NCT01727141 and NCT01712516.

Pseudohyperkalemia: in vitro phenomenon or misdiagnosis. A case report

&lt;b&gt;Introduction:&lt;/b&gt; Hyperkalemia is a common electrolyte disturbance that occurs within many patients. The more often prevalence of cardiovascular or renal diseases is, the more frequent medical issue hyperkalemia will be. An increasing quantity of entities requires taking medications that affect electrolyte hemostasis. Therefore, reasons for hyperkalemia should be deeply reflected. One of them is pseudohyperkalemia. &lt;b&gt;Purpose:&lt;/b&gt; In this study diagnostics and treatment of hypokalemia were presented based on the case report of a 56-year-old man. &lt;b&gt;Case presentation:&lt;/b&gt; A 56-year-old man was admitted to the Department of Invasive Cardiology of Medical Hospital of Białystok for complaints of strong chest pain associated with palpitations, cold sweats, feelings of general weakness and anxiety. The patient had no medical history of chronic diseases and neglected to take any medications at length. The laboratory tests performed at admission showed an increased serum concentration of potassium. Through the whole hospitalization, many medications were implicated to overcome hyperkalemia (diuretics, calcium resonium, inhalation with beta2-adrenergic agonists, intravenous infusion of glucose with insulin) with no effect. Hormone test was performed, the results excluded Addison’s or pituitary disease. Differential diagnosis with arterial blood draw showed normal potassium serum concentration. &lt;b&gt;Conclusions:&lt;/b&gt; Hyperkalemia is encountered in a broad spectrum of patients. The severely elevated level of potassium could lead to life-threating conditions. Therefore, proper diagnosis making process is a matter of great importance. As clinicians, we need to base not only on laboratory but also examine the whole picture of the patient. Misdiagnosing pseudohyperkalemia might result in unnecessary medical management.

Longitudinal evaluation of SMN levels as biomarker for spinal muscular atrophy: results of a phase IIb double-blind study of salbutamol

BackgroundSpinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder, due to the loss of function of the survival motor neuron (SMN1) gene. The first treatment for the condition, recently...

269 Sustainability defined and practiced in a modern cattle feeding enterprise.

Abundant feed grains provided the opportunity for cattle feeders to create an industry that excels in developing light weight cattle produced from diverse pastureland into high quality finished beef. The collective knowledge and best management practices available to today’s commercial cattle feeding industry, developed through trial-and-error and formal research, supports a mature, competitive industry and efficient production. However, interested external groups and consumers have questioned whether cattle feeding satisfies the three pillars of sustainability: environmental, economic, and societal. The use of technology in animal agriculture faces special scrutiny from those who have idealized historical production practices. Technologies available to enhance production efficiency include those applied directly to the animal and those included in the feed. Growth promotion through hormone implants and beta-adrenergic agonists provide benefits through increased production, while ionophores improve efficiency through reducing inputs and increasing production. Reducing their use can have negative environmental impacts. In addition, antibiotic use from classes important to human medicine face pressures from many concerned about the increasing prevalence of antibiotic-resistant bacteria challenging both human and animal health. As these antibiotics are used to treat, control, and prevent disease, the most effective way to decrease use is by improving cattle health outcomes through other means. Alternative ration compositions can improve liver abscess outcomes, but result in increased feed usage and decreased HCW from each animal. Addressing Bovine Respiratory Disease in the feedyard is best accomplished through ensuring cattle are prepared prior to arrival. Finally, an effort to better understand contributions to resistance must accompany an antibiotic use strategy. Less controversial technologies support operational efficiency, data collection, and information utilization. Their challenges include demonstrating usefulness, implementation, and the possibility of discouraging skilled labor (animal husbandry) by relying on machines. Alteration of any production strategy challenges the economic status quo and introduces risk into the business.

Leptin and HPA axis activity in diabetic rats: Effects of adrenergic agonists

Type I Diabetes (T1D) is associated with reduced leptin levels and increased stress axis activity marked by elevations in norepinephrine (NE) levels in the paraventricular nucleus (PVN) of the hypothalamus. We hypothesized that leptin suppresses stress axis activity in T1D through central and peripheral mechanisms. In the first experiment, adult male Sprague Dawley rats were implanted with a cannula in the PVN and randomly divided into a non-diabetic group treated with vehicle (n = 6) and a diabetic group treated with streptozotocin (n = 13). Food intake and water intake was measured for 14 days. On the last day, a subset of diabetic rats were treated with 500 µg of leptin i.p. Rats were subjected to push-pull perfusion of the PVN and hourly blood sampling for 5 h. In the next experiment, diabetic rats were treated either with an alpha-2 adrenergic agonist, clonidine (CLON), or a beta adrenergic agonist isoproterenol (ISO), to reverse the effects of leptin. Rats were subjected to push pull perfusion and hourly blood sampling. In experiment 1, T1D increased food intake, water intake, NE release in the PVN and circulating CS levels. Leptin treatment decreased NE release modestly but produced a robust reduction in corticosterone (CS) levels. In experiment 2, CLON but not ISO was able to reverse the effect of leptin on NE levels in the PVN, however, both agonists were capable of blocking leptin’s effects on circulating CS. These results suggest that in diabetic rats, the sensitivity of the hypothalamus to beta adrenergic agonists is altered, while the adrenals remain sensitive to both alpha and beta adrenergic agonists.

Effect of Montelukast 10 mg in Elderly Patients with Mild and Moderate Asthma Compared with Young Adults. Results of a Cohort Study

Background:The clinical characteristics and physio-pathogenic mechanisms of asthma in patients older than 60 years appear to differ from the behavior described for other age groups. Therefore, the effectiveness of medications for elderly patients with asthma should not be extrapolated from studies conducted on teenagers or young adults.Objective: The study aimed to establish the clinical effect of montelukast 10 mg in elderly patients with mild and moderate asthma compared to its effect on young adults.Method:A prospective cohort study was conducted during 12 weeks of follow-up, which consecutively included the total population of adult patients attended by a group of 21 general practitioners, between July and December 2016. Young adults (18-59 years) and older adults were included (60 years or older) with mild or moderate asthma, which, according to the criteria of his treating physician, had been prescribed montelukast 10 mg/day. The variables of interest were: use of inhaled corticosteroids during the last month, use of inhaled beta-2 adrenergic agonists as a rescue in the last month, having attended the emergency service during the last month due to an asthma attack, presence of wheezing in the physical examination, the number of attacks in the last month and the number of days without symptoms in the last month.Results:A total of 126 patients entered the cohort and 104 completed the follow-up, of which 29% were older adults. On admission, 65.4% of patients (68/104) had used rescue inhaled beta2 in the last month and had been using schemes with corticosteroids. After 12 weeks of follow-up, 58.1% (43/74) of the young adults required treatment schedules with corticosteroids, while in the elderly, only 36.7% of the patients (11/30) required this treatment scheme (p-value: 0.047). Regarding the use of rescue inhaled beta-2 at 12 weeks, 55% of young adults reported using them, compared to 33.3% of older adults (p-value: 0.041).Conclusion:In this cohort of patients, treated with montelukast 10 mg/day for 12 weeks, there was a reduction of broncho-obstructive symptoms and exacerbations of the disease. In older adults compared to young adults, a greater reduction in the use of beta2 agonists rescue medications and in the concomitant use of inhaled corticosteroid schemes was documented.

Between an ugly truth and a perfect lie: Wiping off fearful memories using beta-adrenergic receptors antagonists.

Psychiatric disorders such as anxiety, phobias, and post-traumatic stress disorder are considered of high global prevalence. Currently, a therapeutic approach to treat these disorders using beta-blockers, which antagonize the beta-adrenergic receptors (B1, B2, and B3) is being studied. This approach claims that beta-blockers, such as propranolol, inhibit fear memory reconsolidation. However, there are several studies refuting such claims by discrediting their experimental design and pointing out both the drugs pharmacokinetic properties and confounding factors. In this review, we explore the different effects of central beta-adrenergic agonists and antagonists on the fear memory consolidation providing mixed-evidence, limitations, and future directions.

The Beta-adrenergic agonist, Ractopamine, increases skeletal muscle expression of Asparagine Synthetase as part of an integrated stress response gene program

Synthetic beta-adrenergic agonists (BA) have broad biomedical and agricultural application for increasing lean body mass, yet a poor understanding of the biology underpinning these agents is limiting further drug discovery potential. Growing female pigs (77 ± 7 kg) were administered the BA, Ractopamine (20 ppm in feed), or the recombinant growth hormone (GH), Reporcin (10 mg/48 hrs injected) for 1, 3, 7, 13 (n = 10 per treatment, per time point) or 27 days (n = 15 per treatment). Using RNA-sequencing and inferred pathway analysis, we examined temporal changes to the Longissimus Dorsi skeletal muscle transcriptome (n = 3 per treatment, per time point) relative to a feed-only control cohort. Gene expression changes were affirmed by quantitative-PCR on all samples (n = 164). RNA-sequencing analysis revealed that BA treatment had greater effects than GH, and that asparagine synthetase (Asns) was the 5th most significantly increased gene by BA at day 3. ASNS protein expression was dramatically increased by BA treatment at day 7 (p < 0.05). The most significantly increased gene at day 3 was activating transcription factor 5 (Atf5), a transcription factor known to regulate ASNS gene expression. Gene and protein expression of Atf4, another known regulator of Asns expression, was not changed by BA treatment. Expression of more than 20 known Atf4 target genes were increased by BA treatment, suggesting that BA treatment induces an integrated stress response (ISR) in skeletal muscle of pigs. In support of this, mRNA expression of sestrin-2 (Sesn2) and cyclin-dependant kinase 1 alpha (Cdkn1a), two key stress-responsive genes and negative regulators of cellular growth, were also strongly increased from day 3 of BA treatment. Finally, tRNA charging was the most significantly enriched pathway induced by BA treatment, suggesting alterations to the translational capacity/efficiency of the muscle. BA-mediated changes to the skeletal muscle transcriptome are highly indicative of an integrated stress response (ISR), particularly genes relating to amino acid biosynthesis and protein translational capacity.

Beta-adrenergic receptor activation increases GABA uptake in adolescent mice frontal cortex: Modulation by cannabinoid receptor agonist WIN55,212-2

GABA transporters regulate synaptic GABA levels and dysfunctions in this system might result in psychiatric disorders. The endocannabinoid system (ECS) is the main circuit breaker in the nervous system and may alter noradrenaline (NA) communication, which in turn modulates the release of GABA. However, a close relationship between these systems has not been recognized. We asked whether NA and ECS might control extracellular GABA levels in slices of frontal cortex (FC) of adolescent Swiss mice with 40 days after birth (PN40). Here we show that NA and isoproterenol (ISO), a beta-adrenergic agonist, increased [3H]-GABA uptake in mice FC, while alpha1-adrenergic agonist phenylephrine had no effect. As GAT-1 is expressed and fully functional at the FC, addition of NO-711, a GAT-1 inhibitor, dose dependently blocked [3H]-GABA uptake. The increase of [3H]-GABA uptake induced by ISO was also blocked by NO-711. [3H]-GABA release induced by 80 mM KCl was reduced by NO-711, but not by removal of Ca2+. ISO also increased cyclic AMP (cAMP) levels and addition of WIN 55,212-2, a mixed CB1/CB2 receptor agonist, inhibited the effect of ISO in GABA uptake increase, GAT-1 expression and cAMP levels compared to control. Our data show that GABA transport increased by NA and ISO is negatively regulated by cannabinoid receptor agonist WIN55,212-2.

Beta-2 Adrenergic and Glucocorticoid Receptor Agonists Modulate Ozone-Induced Pulmonary Protein Leakage and Inflammation in Healthy and Adrenalectomized Rats.

We have shown that acute ozone inhalation activates sympathetic-adrenal-medullary and hypothalamus-pituitary-adrenal stress axes, and adrenalectomy (AD) inhibits ozone-induced lung injury and inflammation. Therefore, we hypothesized that stress hormone receptor agonists (β2 adrenergic-β2AR and glucocorticoid-GR) will restore the ozone injury phenotype in AD, while exacerbating effects in sham-surgery (SH) rats. Male Wistar Kyoto rats that underwent SH or AD were treated with vehicles (saline + corn oil) or β2AR agonist clenbuterol (CLEN, 0.2 mg/kg, i.p.) + GR agonist dexamethasone (DEX, 2 mg/kg, s.c.) for 1 day and immediately prior to each day of exposure to filtered air or ozone (0.8 ppm, 4 h/day for 1 or 2 days). Ozone-induced increases in PenH and peak-expiratory flow were exacerbated in CLEN+DEX-treated SH and AD rats. CLEN+DEX affected breath waveform in all rats. Ozone exposure in vehicle-treated SH rats increased bronchoalveolar lavage fluid (BALF) protein, N-acetyl glucosaminidase activity (macrophage activation), neutrophils, and lung cytokine expression while reducing circulating lymphocyte subpopulations. AD reduced these ozone effects in vehicle-treated rats. At the doses used herein, CLEN+DEX treatment reversed the protection offered by AD and exacerbated most ozone-induced lung effects while diminishing circulating lymphocytes. CLEN+DEX in air-exposed SH rats also induced marked protein leakage and reduced circulating lymphocytes but did not increase BALF neutrophils. In conclusion, circulating stress hormones and their receptors mediate ozone-induced vascular leakage and inflammatory cell trafficking to the lung. Those receiving β2AR and GR agonists for chronic pulmonary diseases, or with increased circulating stress hormones due to psychosocial stresses, might have altered sensitivity to air pollution.

Treating Pediatric Asthma According Guidelines.

Asthma is a common chronic inflammatory disorder of the lower respiratory airways in childhood. The management of asthma exacerbations and the disease control are major concerns for clinical practice. The Global Strategy for Asthma Management and Prevention, published by GINA, updated in 2017, the British Thoracic Society/Scottish Intercollegiate Guideline Network, revised in 2016, the National Institute for Health and Care Excellence asthma guideline consultation, available in 2017, are widely accepted documents, frequently implemented, with conflicting advices, and different conclusion on asthma definition and treatment. An International Consensus on Pediatric Asthma was carried out in 2012 by a Committee with expertise in the field, to critically review differences on current guidelines. In addition, the specific issue of treating severe and difficult asthma has been recently highlighted throughout the International European Respiratory Society/American Thoracic Society guidelines on severe asthma. The aim of this paper is to describe conventional treatments and some new therapeutic approaches to pediatric asthma according to guidelines, highlighting key aspects, and differences on proposed clinical recommendations for asthma management. Age specific therapy are proposed in steps, according to clinical severity and the level of disease control. If control is not achieved within 3 months, stepping-up should be considered; otherwise, if control is achieved after 3 months, stepping down may be considered. The most used drug classes of asthma medications are beta-2 adrenergic agonists, corticosteroids, and leukotriene modifiers. Intramuscolar triamcinolone has been used for severe asthma treatment. Chromones and xanthines have been extensively used in the past, but they have shown limits related to their efficacy and safety profile. Omalizumab, a monoclonal antibody against IgE, is an immunomodulatory biological agent, used as new drug in patients with confirmed IgE-mediated allergic asthma, only for patient's specific range of total IgE level. There are low evidences in the efficacy of metotrexate, as well as macrolide antibiotics in children with asthma. Antifungal agents are also not recommended in asthmatic patients. Non-pharmacological measures that may improve patient's quality of life should also be attempted. We conclude that treatment decisions on childhood asthma management should be critically made, pondering the differences suggested by agreed international consensus documents.

Does Urodynamics Impact the Outcomes of Third-line Therapy of Refractory OAB (or Refractory Urgency Urinary Incontinence)?

Overactive bladder (OAB) is highly prevalent with increasing age. Conservative management including lifestyle adaptation, controlled fluid intake, and bladder training are considered first-line therapeutic options. Second-line options are medication such as antimuscarinics or beta-3 adrenergic receptor agonists. Therapy refractory patients should be referred to a specialist for further evaluation. It currently remains unclear if patients should undergo routine urodynamic investigation (UDI) before offering third-line therapies like sacral neuromodulation (SNM) or intradetrusor injection of onabotulinumtoxinA (IdetInBotA). The aim of this narrative review was to assess if the presence of detrusor overactivity (DO) can predict treatment success of third-line therapies for OAB. There is only limited evidence available for both IdetInBotA and SNM, but treatment success does not appear to be related to the presence of DO in baseline UDI. Hence, routine UDI is not mandatory in patients with OAB but remains an option when its outcome is likely to change the treatment strategy or to assess the risk of upper urinary tract deterioration.

The beta-adrenergic receptor agonist, terbutaline, reduces UVB-induced mechanical sensitization in humans.

Previously, we found in cultures of primary neurons and in animals that sensitized primary neurons can be desensitized by treatment with e.g. beta-adrenergic receptor agonists. We now tested whether also in human sensitization such as UVB-radiation induced sunburn-like hyperalgesia can be reduced by intradermal injection of the beta-adrenergic receptor agonist terbutaline. In our prospective randomized study, 17 participants received an individual UVB dose to cause a defined local sunburn-like erythema at four locations, two on each forearm. Twenty-four hours later, the sensitized four areas were injected intradermally with terbutaline pH 4.3, terbutaline pH 7.0, saline pH 4.3 or saline pH 7.0, respectively. Pain thresholds were examined before and after induction of UVB-sensitization, and 15, 30 and 60min after injection of the respective solution. Mechanical pain thresholds of the skin and of deeper tissues were determined by pinprick and pressure algometer measurements, respectively. UVB-irradiation decreased mechanical pain thresholds for pinprick and pressure algometer measurements demonstrating a successful sunburn-like sensitization. Intradermal injection of terbutaline pH 7.0 into the sensitized skin reduced the sensitization for all measured timepoints as determined by pinprick measurements. Pinprick measurements of sensitization were not reduced by injection of terbutaline pH 4.3, saline solution pH 7.0 or saline solution pH 4.3. Also, sensitization of deeper tissue nociceptors were not altered by any of the injections as measured with the pressure algometer. Similar to our cellular observations, also in humans beta-adrenergic agonists such as terbutaline can reduce the sensitization of primary neurons in the skin. We previously showed in model systems that beta-adrenergic stimulation can not only sensitize but also desensitize nociceptors. Our study shows that also in humans beta-adrenergic agonists desensitize if injected into UVB-sensitized skin. This indicates an analgesic activity of adrenergic agonists in addition to their vasoconstrictory function.

Abstract 426: Stress-induced Kinase Targets of Cardioprotective 3’,4’-dihydroxyflavonol in Injured Myocardium

3’,4’-dihydroxyflavonol (DiOHF) is a synthetic flavonol in a class of phytochemicals known as flavonoids can have beneficial biological properties. Previous studies revealed that intravenous administration of DiOHF immediately preceding myocardial reperfusion potently reduced infarct size in anaesthetised sheep that was comparable to ischemic preconditioning and the protective effects of DiOHF were recapitulated ex vivo during ischemia/reperfusion (I/R) of Langendorff-perfused rat hearts and in vitro on isolated cardiac myocytes. These studies highlight the therapeutic potential of DiOHF, with derivatives recently entering Phase II trials for the reduction of ventricular injury and contractile dysfunction following myocardial infarction (NCT02557217). In our current study, we confirmed potent cytoprotective effects of DiOHF in preventing apoptotic and necrotic death of primary rat cardiomyocytes. In addition, we revealed potent anti-hypertrophic effects in cardiomyocytes stimulated with alpha and beta-adrenergic agonists. In comparison with structurally similar compounds, fisetin, quercetin and dihydroxyflavone, DiOHF exhibited enhanced anti-hypertrophic and protective properties. The molecular targets of DiOHF that underpin it’s beneficial effects are of immense interest as they aid clinical development of derivative compounds, rational design of new compounds with biological activity and provide novel insights into the regulatory mechanisms that define the protected myocardium. In exploring the DiOHF mechanisms of action, we had previously reported DiOHF inhibited Ca2+/calmodulin dependent protein kinase II (CaMKII) activity in in vitro kinase assays and in cultured myoblasts. Here, we used resin-immobilized DiOHF for affinity purification from heart tissue lysates and confirmed direct drug-interaction with CaMKII/p-CaMKII from injured rat myocardium (I/R). In addition, we revealed DiOHF interaction and direct inhibition of apoptosis-signal regulated kinase (ASK1) from I/R rat hearts. Our ongoing studies will define whether flavonol inhibition of CaMKII and ASK1 defines protective benefits of DiOHF in the injured myocardium.

The β-Adrenergic Agonist Albuterol Improves Pulmonary Vascular Reserve in Heart Failure with Preserved Ejection Fraction: A Randomized Controlled Trial

Background Heart failure with preserved ejection fraction (HFpEF) is associated with pulmonary vascular dysfunction, particularly during exercise. Pulmonary vasodilators may favorably reduce pulmonary artery (PA) tone in HFpEF, but this could theoretically worsen left atrial hypertension and pulmonary congestion. Objective To evaluate whether the inhaled β-adrenergic agonist albuterol would improve PA vascular function during exercise in HFpEF. Methods We performed a randomized double blind placebo controlled trial testing the effects of inhaled albuterol on resting and exercise hemodynamics in HFpEF using high fidelity micromanometer catheters and expired gas analysis. The primary end point was pulmonary vascular resistance (PVR) during exercise. Results Subjects with HFpEF (n=30) underwent resting and exercise hemodynamic assessment and were then randomized 1:1 to inhaled, nebulized albuterol or placebo, followed by repeat assessment of rest and exercise hemodynamics. Albuterol improved the primary endpoint of exercise PVR as compared to placebo (−0.6±0.5 vs +0.1±0.7 Wood units, p=0.003). As compared to placebo, albuterol enhanced PA compliance with exercise, improved cardiac output reserve and RV-PA coupling, reduced right atrial and pulmonary artery pressures, and enhanced left ventricular transmural distending pressure during exercise (all p Conclusions Albuterol improves pulmonary vascular function and cardiac hemodynamics with exercise in patients with HFpEF. Further study is warranted to evaluate the chronic efficacy of β-agonists and other pulmonary vasoactive medicines in this population. Clinical Trial Registration: Inhaled Beta-adrenergic agonists to Treat Pulmonary Vascular Disease in Heart Failure with Preserved Ejection Fraction (BEAT HFpEF) - NCT02885636. https://clinicaltrials.gov/ct2/show/NCT02885636

Sepsis-induced myocardial dysfunction.

Sepsis leads to a complex intramyocardial inflammatory response that results in sepsis-induced myocardial dysfunction. Here, recent findings are reviewed in a physiologic context. Decreased systolic contractility during sepsis limits ventricular ejection and stroke volume. Initially, this effect is compensated for by increased diastolic filling during volume resuscitation. Reduced afterload due to arterial vasodilation also compensates so that cardiac output can be maintained or increased. Recent results recognize the importance of diastolic dysfunction, reduced ventricular diastolic compliance that impedes ventricular filling. Diastolic dysfunction becomes increasingly important as severity of septic shock increases. When impaired ventricular ejection is coupled with limited diastolic filling, stroke volume must decrease. Accordingly, diastolic dysfunction is more closely related to mortality than systolic dysfunction. Recent trials of beta-adrenergic agonists and levosimendan have been disappointing, while approaches to modulating the intramyocardial inflammatory response show promise. Sepsis-induced myocardial dysfunction is increasingly recognized as a major contributor to outcome of septic shock. Significant strides have been made in understanding the intramyocardial inflammatory response that causes myocardial dysfunction. A number of novel approaches show promise by modulating the intramyocardial inflammatory response.

Effect of sodium 4-phenylbutyrate on Clenbuterol-mediated muscle growth.

Previously, we highlighted induction of an integrated stress response (ISR) gene program in skeletal muscle of pigs treated with a beta-adrenergic agonist. Hence we tested the hypothesis that the ER-stress inhibitor, sodium 4-phenylbutyrate (PBA), would inhibit Clenbuterol-mediated muscle growth and reduce expression of genes that are known indicators of an ISR in mice. Clenbuterol (1mg/kg/day) administered to C57BL6/J mice for 21 days increased body weight (p<0.001), muscle weights (p<0.01), and muscle fibre diameters (p<0.05). Co-administration of PBA (100mg/kg/day) did not alter the Clenbuterol-mediated phenotype, nor did PBA alone have any effects compared to that of the vehicle treated mice. Clenbuterol increased skeletal muscle mRNA expression of phosphoserine amino transferase 1 (PSAT1, p<0.001) and cyclophillin A (p<0.01) at day 3, but not day 7. Clenbuterol decreased mRNA expression of activating transcription factor (ATF) 4 and ATF5 at day 3 (p<0.05) and day 7 (p<0.01), X-box binding protein 1 (XBP1) variant 2 mRNA at day 3 only (p<0.01) and DNA damage inducible transcript 3 (DDIT3/CHOP) mRNA at day 7 only (p<0.05). Co-administration of PBA had no effect on Clenbuterol-induced changes in skeletal muscle gene expression. In contrast, treatment of C2C12 myotubes with 5mM PBA (8hr) attenuated the thapsigargin-induced ISR gene program. Prolonged (24-48hr) treatment with PBA caused atrophy (p<0.01), reduced neoprotein synthesis (p<0.0001) and decreased expression of myogenin and fast myosin heavy chain genes (p<0.01), indicating an inhibition of myogenic differentiation. In summary, Clenbuterol did not induce an ISR gene program in mouse muscle. On the contrary, it reduced expression of a number of ISR genes, but it increased expression of PSAT1 mRNA. Co-administration of PBA had no effect on Clenbuterol-mediated muscle growth or gene expression in mice, whereas PBA did inhibit thapsigargin-induced ISR gene expression in cultured C2C12 cells and appeared to inhibit myogenic differentiation, independent of altering ISR gene expression.

Congenital Myasthenic Syndromes: a Clinical and Treatment Approach.

Congenital myasthenia syndromes are clinically and genetically heterogeneous but treatable conditions. Careful selection of drug therapy is paramount as the same drug can be effective, ineffective, and even harmful in different congenital myasthenia syndromes. The purpose of this article is to review current treatment options for these conditions. Next-generation sequencing has accelerated the discovery of new genes and facilitated the description of novel congenital myasthenic syndromes. Retrospective therapy data from these newly identified syndromes has provided additional insight on the management of these conditions. Cholinergic agents, β-adrenergic agonists, and open-channel blockers remain the principal treatment modalities, and their optimal use depends on an accurate genetic diagnosis and the timely clinical recognition of the disease. In particular, pyridostigmine, usually a first-line agent, should be avoided in DOK7, acetylcholinesterase deficiency, and slow-channel congenital myasthenic syndromes. Beta-adrenergic agonists have been recognized as a first-line agent for a number of congenital myasthenic syndromes, particularly DOK7 and acetylcholinesterase deficiency, whereas long-lived open-channel blockers of the acetylcholine receptor (AChR) ion channel are indicated for the slow-channel congenital myasthenic syndrome. Beta-adrenergic agonists additionally have an important adjunct treatment for congenital myasthenia syndrome due to glycosylation defects, fast channel syndrome, AChR deficiency, and choline acetyltransferase deficiency (ChaT) and therefore may be particularly important in the treatment of syndromes due to defects in motor endplate development and repair. Unlike in autoimmune myasthenia gravis, there is no role for immunotherapy in congenital myasthenic syndromes. If available, a genetic diagnosis should drive the choice for a first-line treatment agent between cholinergic agents, β-adrenergic agents, and open-channel blockers. Evaluation and supportive care at centers with experience in these rare syndromes likely are paramount in achieving optimal outcomes. Furthermore, gene discovery for congenital myasthenic syndromes has provided novel insights on the role of protein glycosylation, endplate maintenance and repair, and synaptic vesicle exocytosis in neuromuscular transmission. These insights may lead to new therapeutic strategies in both congenital and autoimmune myasthenic diseases in the future.

Rationale and design of a multicentre, randomized, placebo-controlled trial of mirabegron, a Beta3-adrenergic receptor agonist on left ventricular mass and diastolic function in patients with structural heart disease Beta3-left ventricular hypertrophy (Beta3-LVH).

AimsProgressive left ventricular (LV) remodelling with cardiac myocyte hypertrophy, myocardial fibrosis, and endothelial dysfunction plays a key role in the onset and progression of heart failure with preserved ejection fraction. The Beta3‐LVH trial will test the hypothesis that the β3 adrenergic receptor agonist mirabegron will improve LV hypertrophy and diastolic function in patients with hypertensive structural heart disease at high risk for developing heart failure with preserved ejection fraction.Methods and resultsBeta3‐LVH is a randomized, placebo‐controlled, double‐blind, two‐armed, multicentre, European, parallel group study. A total of 296 patients will be randomly assigned to receive either mirabegron 50 mg daily or placebo over 12 months. The main inclusion criterion is the presence of LV hypertrophy, that is, increased LV mass index (LVMi) or increased wall thickening by echocardiography. The co‐primary endpoints are a change in LVMi by cardiac magnetic resonance imaging and a change in LV diastolic function (assessed by the E/e′ ratio). Secondary endpoints include mirabegron's effects on cardiac fibrosis, left atrial volume index, maximal exercise capacity, and laboratory markers. Two substudies will evaluate mirabegron's effect on endothelial function by pulse amplitude tonometry and brown fat activity by positron emission tomography using 17F‐fluorodeoxyglucose. Morbidity and mortality as well as safety aspects will also be assessed.ConclusionsBeta3‐LVH is the first large‐scale clinical trial to evaluate the effects of mirabegron on LVMi and diastolic function in patients with LVH. Beta3‐LVH will provide important information about the clinical course of this condition and may have significant impact on treatment strategies and future trials in these patients.

Beta-2 Adrenergic Receptor Agonists Enhance AChR Clustering in C2C12 Myotubes: Implications for Therapy of Myasthenic Disorders.

Background:Congenital myasthenic syndromes (CMS) are a group of inherited neuromuscular transmission disorders causing fatiguable muscle weakness. ADRB2 agonists have been observed to provide therapeutic benefit where destabilisation of NMJ structures is part of the underlying pathology, such as in DOK7, COLQ and MuSK CMS as well as in slow channel syndrome. However, very little is known about the molecular mechanisms underlying the effects of ADRB2 agonists in CMS.Objective:In vitro investigation into whether an ADRB2 agonist affects the AChR clustering pathway and has the potential to increase the number and stability of AChR clusters.Methods:Cultured C2C12 mouse myotubes overexpressing the common DOK7 frameshift mutation c.1124_1127dupTGCC were incubated with salbutamol sulphate and the effect on AChR cluster numbers were investigated. Moreover, agrin-induced AChR clusters in C2C12 WT cells were left to disperse after agrin-wash-off, and the effects of incubation with salbutamol sulphate on AChR cluster numbers were explored.Results:Salbutamol sulphate induced a significant increase in the number of AChR clusters formed on C2C12 cells overexpressing c.1124_1127dupTGCC. Furthermore, significantly more clusters remained in C2C12 WT myotubes incubated with salbutamol sulphate following agrin wash-off.Conclusions:The results suggest that ADRB2 agonists directly affect proteins located at the neuromuscular junction and exert a stabilising effect on AChR clusters.