Structural Basis for a Cork-Up Mechanism of the Intra-Molecular Mesaconyl-CoA Transferase.

Mesaconyl-CoA transferase (Mct) is one of the key enzymes of the 3-hydroxypropionate (3HP) bi-cycle for autotrophic CO2 fixation. Mct is a family III/Frc family CoA transferase that catalyzes an unprecedented intra-molecular CoA transfer from the C1-carboxyl group to the C4-carboxyl group of mesaconate at catalytic efficiencies >106 M-1 s-1. Here, we show that the reaction of Mct proceeds without any significant release of free CoA or the transfer to external acceptor acids. Mct catalyzes intra-molecular CoA transfers at catalytic efficiencies that are at least more than 6 orders of magnitude higher compared to inter-molecular CoA transfers, demonstrating that the enzyme exhibits exquisite control over its reaction. To understand the molecular basis of the intra-molecular CoA transfer in Mct, we solved crystal structures of the enzyme from Chloroflexus aurantiacus in its apo form, as well as in complex with mesaconyl-CoA and several covalently enzyme-bound intermediates of CoA and mesaconate at the catalytically active residue Asp165. Based on these structures, we propose a reaction mechanism for Mct that is similar to inter-molecular family III/Frc family CoA transferases. However, in contrast to the latter that undergo opening and closing cycles during the reaction to exchange substrates, the central cavity of Mct remains sealed ("corked-up") by the CoA moiety, strongly favoring the intra-molecular CoA transfer between the C1 and the C4 position of mesaconate.

Enhancing the Substrate Specificity of Clostridium Succinyl-CoA Reductase for Synthetic Biology and Biocatalysis.

Succinyl-CoA reductase (SucD) is an acylating aldehyde reductase that catalyzes the NADPH-dependent reduction of succinyl-CoA to succinic semialdehyde. The reaction sequence from succinate to crotonyl-CoA is of particular interest for several new-to-nature CO2-fixation pathways, such as the crotonyl-CoA/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle, in which SucD plays a key role. However, pathways like the CETCH cycle feature several CoA-ester intermediates, which could be potentially side substrates for this enzyme. Here, we show that the side reaction for most CETCH cycle metabolites is relatively small (<2%) with the exception of mesaconyl-C1-CoA (16%), which represents a competing substrate in this pathway. We addressed this promiscuity by solving the crystal structure of a SucD of Clostridium kluyveri in complex with NADP+ and mesaconyl-C1-CoA. We further identified two residues (Lys70 and Ser243) that coordinate mesaconyl-C1-CoA at the active site. We targeted those residues with site-directed mutagenesis to improve succinyl-CoA over mesaconyl-C1-CoA reduction. The best resulting SucD variant, K70R, showed a strongly reduced side activity for mesaconyl-C1-CoA, but the substitution also reduced the specific activity for succinyl-CoA by a factor of 10. Transferring the same mutations into a SucD homologue from Clostridium difficile similarly decreases the side reaction of this enzyme for mesaconyl-C1-CoA from 12 to 2%, notably without changing the catalytic efficiency for succinyl-CoA. Overall, our structure-based engineering efforts provided a highly specific enzyme of interest for several applications in biocatalysis and synthetic biology.

Impact of baseline symptoms and health status on COPD exacerbations in the FLAME study.

BACKGROUND: COPD is a heterogeneous disease and patients may respond differently to therapies depending on baseline symptom burden. METHODS: This post-hoc analysis from the 52-week FLAME study investigated the impact of baseline symptom burden in terms of health status, dyspnoea, bronchitis status, eosinophil levels and smoking status on the subsequent risk of moderate or severe exacerbations. Health status was measured by St. George's Respiratory Questionnaire (SGRQ) score (higher ≥46.6 and lower < 46.6) and COPD Assessment Test (CAT) score (higher ≥17 and lower < 17); dyspnoea and bronchitis were assessed via an electronic diary (eDiary). Differential response to once-daily indacaterol/glycopyrronium (IND/GLY) 110/50 µg versus twice-daily salmeterol/fluticasone (SFC) 50/500 µg was assessed. RESULTS: Data from 3354 patients was analysed. The risk of exacerbations was lower in patients who had less severe health impairment (rate ratio [RR] [95% CI]): SGRQ-C, (0.88 [0.78, 0.99]); CAT, 0.85 [0.75, 0.96]) and lower dyspnoea (0.79 [0.69, 0.90]) at baseline versus those with more severe health impairment and higher dyspnoea, respectively. Compared with SFC, IND/GLY led to better prevention of moderate-to-severe exacerbations in the majority of groups studied. CONCLUSION: Patients with more severe health status impairment and greater symptom burden at baseline subsequently experienced more exacerbations in the FLAME study. IND/GLY was overall more effective in preventing exacerbations versus SFC, regardless of baseline symptom burden. Our results suggest that future studies on novel exacerbation therapies should consider targeting patients with higher symptom burden at baseline. CLINICAL TRIAL IDENTIFIER: NCT01782326.

Long-Term Triple Therapy De-escalation to Indacaterol/Glycopyrronium in Patients with Chronic Obstructive Pulmonary Disease (SUNSET): A Randomized, Double-Blind, Triple-Dummy Clinical Trial.

RATIONALE: There are no studies on withdrawal of inhaled corticosteroids in patients on long-term triple therapy in the absence of frequent exacerbations. OBJECTIVES: To evaluate the efficacy and safety of direct de-escalation from long-term triple therapy to indacaterol/glycopyrronium in nonfrequently exacerbating patients with chronic obstructive pulmonary disease (COPD). METHODS: This 26-week, randomized, double-blind, triple-dummy study assessed the direct change from long-term triple therapy to indacaterol/glycopyrronium (110/50 µg once daily) or continuation of triple therapy (tiotropium [18 µg] once daily plus combination of salmeterol/fluticasone propionate [50/500 µg] twice daily) in nonfrequently exacerbating patients with moderate-to-severe COPD. Primary endpoint was noninferiority on change from baseline in trough FEV1. Moderate or severe exacerbations were predefined secondary endpoints. MEASUREMENTS AND MAIN RESULTS: A total of 527 patients were randomized to indacaterol/glycopyrronium and 526 to triple therapy. Inhaled corticosteroids withdrawal led to a reduction in trough FEV1 of -26 ml (95% confidence interval, -53 to 1 ml) with confidence limits exceeding the noninferiority margin of -50 ml. The annualized rate of moderate or severe COPD exacerbations did not differ between treatments (rate ratio, 1.08; 95% confidence interval, 0.83 to 1.40). Patients with ≥300 blood eosinophils/µl at baseline presented greater lung function loss and higher exacerbation risk. Adverse events were similar in the two groups. CONCLUSIONS: In patients with COPD without frequent exacerbations on long-term triple therapy, the direct de-escalation to indacaterol/glycopyrronium led to a small decrease in lung function, with no difference in exacerbations. The higher exacerbation risk in patients with ≥300 blood eosinophils/µl suggests that these patients are likely to benefit from triple therapy. Clinical trial registered with www.clinicaltrials.gov (NCT 02603393).

Engineering a new-to-nature cascade for phosphate-dependent formate to formaldehyde conversion in vitro and in vivo.

Formate can be envisioned at the core of a carbon-neutral bioeconomy, where it is produced from CO2 by (electro-)chemical means and converted into value-added products by enzymatic cascades or engineered microbes. A key step in expanding synthetic formate assimilation is its thermodynamically challenging reduction to formaldehyde. Here, we develop a two-enzyme route in which formate is activated to formyl phosphate and subsequently reduced to formaldehyde. Exploiting the promiscuity of acetate kinase and N-acetyl-γ-glutamyl phosphate reductase, we demonstrate this phosphate (Pi)-based route in vitro and in vivo. We further engineer a formyl phosphate reductase variant with improved formyl phosphate conversion in vivo by suppressing cross-talk with native metabolism and interface the Pi route with a recently developed formaldehyde assimilation pathway to enable C2 compound formation from formate as the sole carbon source in Escherichia coli. The Pi route therefore offers a potent tool in expanding the landscape of synthetic formate assimilation.

Long-term effectiveness and safety of omalizumab in pediatric and adult patients with moderate-to-severe inadequately controlled allergic asthma.

Omalizumab is recommended as an add-on therapy in patients aged ≥6 years with inadequately controlled, moderate-to-severe persistent allergic asthma. The efficacy and safety of omalizumab treatment in allergic asthma clinical trials and its effectiveness in the real world have been reported in numerous studies. In this review, we examine clinical evidence in pediatric and adult patients with allergic asthma who received omalizumab treatment for at least 2 years, to assess its effectiveness, durability, and trajectory of response over time as well as safety. We performed a literature search from inception until March 2022 in PubMed using the keywords "omalizumab" and "allergic asthma" to retrieve articles examining the effects of omalizumab in patients with allergic asthma, aged ≥6 years. Only articles that evaluated the effectiveness of omalizumab for at least 2 years were included. Data from case reports were excluded. Our review confirmed the long-term effectiveness and safety of omalizumab, demonstrating reduced rate of exacerbations, improved lung function, asthma control, and quality of life, decreased health care resource utilization, and use of corticosteroids (oral/inhaled) with a favorable safety and tolerability profile for up to 9 years in adult patients with moderate-to-severe allergic asthma. Similar results were also observed in the pediatric population with up to 7.5 years of omalizumab treatment. This review highlights and confirms the sustained clinical benefits of omalizumab over long periods of treatment in pediatric and adult populations with allergic asthma.

On the flexibility of the cellular amination network in E coli.

Ammonium (NH4+) is essential to generate the nitrogenous building blocks of life. It gets assimilated via the canonical biosynthetic routes to glutamate and is further distributed throughout metabolism via a network of transaminases. To study the flexibility of this network, we constructed an Escherichia coli glutamate auxotrophic strain. This strain allowed us to systematically study which amino acids serve as amine sources. We found that several amino acids complemented the auxotrophy either by producing glutamate via transamination reactions or by their conversion to glutamate. In this network, we identified aspartate transaminase AspC as a major connector between many amino acids and glutamate. Additionally, we extended the transaminase network by the amino acids ß-alanine, alanine, glycine, and serine as new amine sources and identified d-amino acid dehydrogenase (DadA) as an intracellular amino acid sink removing substrates from transaminase reactions. Finally, ammonium assimilation routes producing aspartate or leucine were introduced. Our study reveals the high flexibility of the cellular amination network, both in terms of transaminase promiscuity and adaptability to new connections and ammonium entry points.

Nitrogen is an essential part of many of the cell's building blocks, including amino acids and nucleotides, which form proteins and DNA respectively. Therefore, nitrogen has to be available to cells so that they can survive and grow. In nature, some microorganisms convert the gaseous form of nitrogen into ammonium, which then acts as the nitrogen source of most organisms, including bacteria, plants and animals. Once cells take up ammonium, it is 'fixed' by becoming part of an amino acid called glutamate, which has a so-called 'amine group' that contains a nitrogen. Glutamate then becomes the central source for passing these amines on to other molecules, distributing nitrogen throughout the cell. This coupling between ammonium fixation and glutamate production evolved over millions of years and occurs in all organisms. However, the complete metabolic network that underlies the distribution of amines remains poorly understood despite decades of research. Furthermore, it is not clear whether ammonium can be fixed in a way that is independent of glutamate. To answer these questions, Schulz-Mirbach et al. used genetic engineering to create a strain of the bacterium E. coli that was unable to make glutamate. These mutant cells could only grow in the presence of certain amino acids, which acted as alternative amine sources. Schulz-Mirbach et al. found that enzymes called transaminases, and one called AspC in particular, were required for the cells to be able to produce glutamate using the amine groups from other amino acids. Notably, Schulz-Mirbach et al. showed that AspC, which had previously been shown to use an amino acid called aspartate as a source of amine groups, is indispensable if the cell is to use the amine groups from other amino acids ­ including histidine, tyrosine, phenylalanine, tryptophan, methionine, isoleucine and leucine. Schulz-Mirbach et al. also discovered that if they engineered the E. coli cells to produce transaminases from other species, the repertoire of molecules that the cells could use as the source of amines to generate glutamate increased. In a final set of experiments, Schulz-Mirbach et al. were able to engineer the cells to fix ammonium by producing aspartate and leucine, thus entirely bypassing the deleted routes of glutamate synthesis. These data suggest that fixing ammonium and distributing nitrogen in E. coli can be very flexible. The results from these experiments may shed light on how cells adapt when there is not a lot of ammonium available. Moreover, this study could advance efforts at metabolic engineering, for example, to create molecules through new pathways or to boost the production of amino acids needed for industrial purposes.

Real-World Effectiveness of Omalizumab in Severe Allergic Asthma: A Meta-Analysis of Observational Studies.

BACKGROUND: Assessment of clinical outcomes in the real-world corroborates findings from randomized controlled trials (RCTs). OBJECTIVE: This meta-analysis evaluated real-world data of omalizumab on treatment response, lung function, exacerbations, oral corticosteroid (OCS) use, patient-reported outcomes (PROs), health care resource utilization (HCRU), and school/work absenteeism at 4, 6, and 12 months after treatment. METHODS: Observational studies in patients with severe allergic asthma (≥6 years) treated with omalizumab for ≥16 weeks, published from January 2005 to October 2018, were retrieved from PubMed, Embase, and Cochrane. A random-effects model was used to assess heterogeneity. RESULTS: In total, 86 publications were included. Global evaluation of treatment effectiveness (GETE) was good/excellent in 77% patients at 16 weeks (risk difference: 0.77; 95% confidence interval [CI]: 0.70-0.84; I2 = 96%) and in 82% patients at 12 months (0.82, 0.73-0.91; 97%). The mean improvement in forced expiratory volume in 1 second was 160, 220, and 250 mL at 16 weeks, 6 months, and 12 months, respectively. There was a decrease in Asthma Control Questionnaire score at 16 weeks (-1.14), 6 months (-1.56), and 12 months (-1.13) after omalizumab therapy. Omalizumab significantly reduced annualized rate of severe exacerbations (risk ratio [RR]: 0.41, 95% CI: 0.30-0.56; I2 = 96%), proportion of patients receiving OCS (RR: 0.59, 95% CI: 0.47-0.75; I2 = 96%), and number of unscheduled physician visits (mean difference: -2.34, 95% CI: -3.54 to -1.13; I2 = 98%) at 12 months versus baseline. CONCLUSION: The consistent improvements in GETE, lung function, and PROs, and reductions in asthma exacerbations, OCS use, and HCRU with add-on omalizumab in real-life confirm and complement the efficacy data of RCTs.

Engineering a Highly Efficient Carboligase for Synthetic One-Carbon Metabolism.

One of the biggest challenges to realize a circular carbon economy is the synthesis of complex carbon compounds from one-carbon (C1) building blocks. Since the natural solution space of C1-C1 condensations is limited to highly complex enzymes, the development of more simple and robust biocatalysts may facilitate the engineering of C1 assimilation routes. Thiamine diphosphate-dependent enzymes harbor great potential for this task, due to their ability to create C-C bonds. Here, we employed structure-guided iterative saturation mutagenesis to convert oxalyl-CoA decarboxylase (OXC) from Methylobacterium extorquens into a glycolyl-CoA synthase (GCS) that allows for the direct condensation of the two C1 units formyl-CoA and formaldehyde. A quadruple variant MeOXC4 showed a 100 000-fold switch between OXC and GCS activities, a 200-fold increase in the GCS activity compared to the wild type, and formaldehyde affinity that is comparable to natural formaldehyde-converting enzymes. Notably, MeOCX4 outcompetes all other natural and engineered enzymes for C1-C1 condensations by more than 40-fold in catalytic efficiency and is highly soluble in Escherichia coli. In addition to the increased GCS activity, MeOXC4 showed up to 300-fold higher activity than the wild type toward a broad range of carbonyl acceptor substrates. When applied in vivo, MeOXC4 enables the production of glycolate from formaldehyde, overcoming the current bottleneck of C1-C1 condensation in whole-cell bioconversions and paving the way toward synthetic C1 assimilation routes in vivo.

Artificial Intelligence/Machine Learning in Respiratory Medicine and Potential Role in Asthma and COPD Diagnosis.

Artificial intelligence (AI) and machine learning, a subset of AI, are increasingly used in medicine. AI excels at performing well-defined tasks, such as image recognition; for example, classifying skin biopsy lesions, determining diabetic retinopathy severity, and detecting brain tumors. This article provides an overview of the use of AI in medicine and particularly in respiratory medicine, where it is used to evaluate lung cancer images, diagnose fibrotic lung disease, and more recently is being developed to aid the interpretation of pulmonary function tests and the diagnosis of a range of obstructive and restrictive lung diseases. The development and validation of AI algorithms requires large volumes of well-structured data, and the algorithms must work with variable levels of data quality. It is important that clinicians understand how AI can function in the context of heterogeneous conditions such as asthma and chronic obstructive pulmonary disease where diagnostic criteria overlap, how AI use fits into everyday clinical practice, and how issues of patient safety should be addressed. AI has a clear role in providing support for doctors in the clinical workplace, but its relatively recent introduction means that confidence in its use still has to be fully established. Overall, AI is expected to play a key role in aiding clinicians in the diagnosis and management of respiratory diseases in the future, and it will be exciting to see the benefits that arise for patients and doctors from its use in everyday clinical practice.

Maximizing Adherence and Gaining New Information For Your Chronic Obstructive Pulmonary Disease (MAGNIFY COPD): Study Protocol for the Pragmatic, Cluster Randomized Trial Evaluating the Impact of Dual Bronchodilator with Add-On Sensor and Electronic Monitoring on Clinical Outcomes.

BACKGROUND: Poor treatment adherence in COPD patients is associated with poor clinical outcomes and increased healthcare burden. Personalized approaches for adherence management, supported with technology-based interventions, may offer benefits to patients and providers but are currently unproven in terms of clinical outcomes as opposed to adherence outcomes. METHODS: Maximizing Adherence and Gaining New Information For Your COPD (MAGNIFY COPD study), a pragmatic cluster randomized trial, aims to evaluate the impact of an adherence technology package (interventional package), comprising an adherence review, ongoing provision of a dual bronchodilator but with an add-on inhaler sensor device and a connected mobile application. This will compare time to treatment failure and other clinical outcomes in patients identified at high risk of exacerbations with historic poor treatment adherence as measured by prescription collection to mono/dual therapy over one year (1312 patients) versus usual care. Treatment failure is defined as the first occurrence of one of the following: (1) moderate/severe COPD exacerbation, (2) prescription of triple therapy (inhaled corticosteroid/long-acting ß2-agonist/long-acting muscarinic antagonist [ICS/LABA/LAMA]), (3) prescription of additional chronic therapy for COPD, or (4) respiratory-related death. Adherence, moderate/severe exacerbations, respiratory-related healthcare resource utilization and costs, and intervention package acceptance rate will also be assessed. Eligible primary care practices (N=176) participating in the Optimum Patient Care Quality Improvement Program will be randomized (1:1) to either adherence support cluster arm (suitable patients already receiving or initiated Ultibro® Breezhaler® [indacaterol/glycopyrronium] will be offered interventional package) or the control cluster arm (suitable patients continue to receive usual clinical care). Patients will be identified and outcomes collected from anonymized electronic medical records within the Optimum Patient Care Research Database. On study completion, electronic medical record data will be re-extracted to analyze outcomes in both study groups. REGISTRATION NUMBER: ISRCTN10567920. CONCLUSION: MAGNIFY will explore patient benefits of technology-based interventions for electronic adherence monitoring.

Fixed-dose combination of indacaterol/glycopyrronium/mometasone furoate once-daily versus salmeterol/fluticasone twice-daily plus tiotropium once-daily in patients with uncontrolled asthma: A randomised, Phase IIIb, non-inferiority study (ARGON).

BACKGROUND: The efficacy and safety of once-daily (o.d.) fixed-dose combination of indacaterol (IND), glycopyrronium (GLY) and mometasone furoate (MF) via Breezhaler® versus concurrent administration of salmeterol/fluticasone (SAL/FLU) twice-daily (b.i.d.) via Accuhaler®+Tiotropium (TIO) o.d. via Respimat® was evaluated in patients with uncontrolled asthma. METHODS: Patients (aged ≥18 years), symptomatic (Asthma Control Questionnaire [ACQ]-7 ≥1.5) despite treatment with long-acting ß2-agonist/inhaled corticosteroid medium- or high-dose, received IND/GLY/MF high- (150/50/160 µg) or medium-dose (150/50/80 µg) o.d. or SAL/FLU high-dose (50/500 µg) b.i.d.+Tio 5 µg o.d. for 24 weeks. The primary objective was to confirm the non-inferiority of either dose of IND/GLY/MF to SAL/FLU high dose + TIO in terms of Asthma Quality of Life Questionnaire (AQLQ). Additional endpoints: ACQ-7, lung function, health status (St George's Respiratory Questionnaire [SGRQ]), exacerbations, and safety after 24 weeks. RESULTS: IND/GLY/MF high- and medium-dose met the primary endpoint, confirming non-inferiority to SAL/FLU high dose + TIO for AQLQ (least square mean treatment difference [Δ]: 0.073 and -0.038, respectively; both p < 0.001). IND/GLY/MF high-dose improved ACQ-7 (Δ: -0.124; p = 0.004), trough FEV1 (Δ: 96 mL; p < 0.001), peak expiratory flow (morning [Δ: 9.56 L/min; p = 0.005], evening [Δ: 9.15 L/min; p = 0.006]) and SGRQ (Δ: -2.00; p = 0.04) versus SAL/FLU high dose + TIO. Improvements in these endpoints were comparable for IND/GLY/MF medium-dose and SAL/FLU high dose + TIO. Adverse events were generally comparable across treatments. CONCLUSIONS: IND/GLY/MF high- and medium-dose o.d. via a single inhaler were non-inferior to SAL/FLU high-dose b.i.d. + TIO o.d. via two inhalers for AQLQ. IND/GLY/MF high-dose o.d. improved lung function, asthma control and health status versus SAL/FLU high dose + TIO, while IND/GLY/MF medium-dose had comparable efficacy but at a corresponding lower steroid dose.

Early Clinically Important Improvement (ECII) and Exacerbation Outcomes in COPD Patients.

Background: Chronic obstructive pulmonary disease (COPD) exacerbations are difficult outcomes to measure in clinical trials. It would be valuable to be able to predict which patients are likely to benefit in terms of exacerbation prevention based on their early response in lung function and symptoms. Methods: This was a post-hoc analysis from the 52-week, randomized, double-blind, double-dummy, non-inferiority FLAME trial. Early clinically important improvement (ECII) was defined as achievement of minimal clinically important difference in trough forced expiratory volume in 1 second (FEV1; ≥100 mL increase) and one patient-reported outcome (PRO): either St. George's Respiratory Questionnaire for COPD (≥4-unit reduction; D1), or COPD assessment test (≥2-point reduction; D2) at Week 4 or 12. Results: Approximately 18-20% of patients achieved ECII at Week 4 or 12 post-randomization according to any of the two definitions. The rate of subsequent exacerbations was lower in patients who achieved ECII at Week 4 (D1: ratio of rates [95% CI], 0.85 [0.74 to 0.98]; D2, 0.88 [0.77 to 1.00]) or at Week 12 (D1, 0.85 [0.74 to 0.98]; D2, 0.86 [0.75 to 1.00]) versus patients not achieving ECII. Patients who achieved ECII experienced longer time-to-first exacerbation between Week 4 or 12 to end of study. More patients achieved ECII with indacaterol/glycopyrronium versus salmeterol/fluticasone according to both definitions at Week 4 (D1, odds ratio [95% CI], 1.69 [1.40 to 2.04]; D2, 1.61 [1.34 to 1.93]), and 12 (D1, 2.01 [1.66 to 2.44]; D2, 1.80 [1.48 to 2.18]). Conclusion: ECII is a novel composite endpoint, based on clinically relevant improvement in lung function and PROs in the early phase of treatment intervention that may predict subsequent exacerbation risk and may be used in clinical trials.

Everolimus inhibits monocyte/macrophage migration in vitro and their accumulation in carotid lesions of cholesterol-fed rabbits.

Monocytes/macrophages recruited into the arterial wall during atherogenesis are crucial in the initiation and progression of atherosclerosis and play a fundamental role in the destabilization process that is the main causal event of acute coronary syndromes. In the present study, we investigated the effect of the mammalian target of rapamycin inhibitor everolimus on macrophage accumulation within carotid lesions elicited by perivascular collar placement in cholesterol-fed rabbits. Everolimus (1.5 mg/kg given 1 day before collaring followed by 1 mg/kg/day for 14 days, administered by oral gavage) markedly decreased lesion macrophage content as compared with vehicle control (-65%; p < 0.01). This effect was associated with a reduction in intimal thickening and occurred in the absence of changes in plasma cholesterol concentrations. To gain insights on the potential mechanism(s) underlying this effect, we investigated the influence of everolimus on chemoattractant-induced migration of human monocytes in vitro. Pretreatment with therapeutic concentrations of everolimus (10 nM) significantly lowered monocyte chemotaxis in response to various chemotactic factors (i.e., monocyte chemoattractant protein-1/CCL2, fractalkine/CX3CL1, interleukin-8/CXCL8, complement fragment 5a, or N-formyl-Met-Leu-Phe) without inducing monocyte cell death. These results suggest that everolimus may favorably influence the atherosclerotic process by affecting the recruitment of monocytes into early lesions.

Omalizumab as alternative to chronic use of oral corticosteroids in severe asthma.

Systemic/oral corticosteroids (OCS) have been used for decades in the management of acute asthma exacerbations and chronically in patients with uncontrolled severe asthma. However, while OCS are effective at treating acute exacerbations, there is only empirical evidence regarding the efficacy of OCS at reducing the rate of exacerbations. Evidence, although scarce, is suggestive of high exacerbation rates in severe asthma patients even when receiving maintenance treatment with OCS. In addition, use of OCS is associated with undesirable effects. Despite all this, physicians have continued to use OCS for managing severe asthma and acute exacerbation due to the lack of availability of effective alternatives. Fortunately, in the last decade several biologics have been proven safe and effective for patients with uncontrolled severe asthma. This has led to the Global Initiative for Asthma (GINA) recommending the use of biologics, instead of maintenance OCS, in patients with severe asthma (GINA Step 5). These include one biologic targeting immunoglobulin E (IgE) (omalizumab), and different biologics targeting interleukin-5 (IL-5), the IL-5 receptor (IL-5R) or IL-4 receptor α-unit (IL-4R α), including mepolizumab (subcutaneous), reslizumab (intravenous), benralizumab (subcutaneous) and dupilumab (subcutaneous). Omalizumab for the treatment of severe allergic asthma reduces exacerbations, irrespective of blood eosinophil levels. Anti-IL-5/IL-5R biologics are indicated in patients with severe eosinophilic asthma and repetitive exacerbations, irrespective of the presence or absence of allergy. Recently, an anti-IL4Rα biologic has been approved by the FDA for eosinophilic phenotype or oral corticosteroid-dependent asthma. Finally, physicians should consider using biologics as an alternative to chronic OCS therapy.

IgE-Mediated Multimorbidities in Allergic Asthma and the Potential for Omalizumab Therapy.

Allergic asthma often coexists with different pathological conditions, called multimorbidities, that are mostly of allergic nature and share a common underlying inflammatory pathophysiological mechanism. Multimorbidities of allergic asthma may influence asthma control, its severity, and patients' response to treatment, and contribute to the overall socioeconomic burden of the disease. Immunoglobulin E (IgE) is known to play a central role in the pathogenesis of various allergic diseases, including asthma. Thus, IgE-mediated immunologic pathways present an attractive target for intervention in asthma and multimorbidities. In this review, we discuss the most frequently reported IgE-mediated multimorbidities in allergic asthma, including allergic rhinitis, rhinoconjunctivitis, atopic dermatitis, vernal keratoconjunctivitis, chronic rhinosinusitis with nasal polyps, food allergies, and allergic bronchopulmonary aspergillosis. Omalizumab is a recombinant humanized monoclonal antibody against IgE and has been in use to treat allergic asthma for more than a decade. We comprehensively review the clinical evidence for omalizumab in the treatment of the aforementioned multimorbidities in allergic asthma.

Surface-textured PEG-based hydrogels with adjustable elasticity: Synthesis and characterization.

Poly(ethylene glycol)-dimethacrylate (PEGDMA)-based hydrogels with adjustable shear modulus within the range of 10kPa to 1MPa and precisely predefinable surface textures on a micro-scale were made. It was observed that the volume of all hydrogels after preparation almost exactly matched the volume of the precursor solution and that there were only slight volume changes upon equilibration in excess solvent. This characteristic swelling behavior enables the preparation of textures on the hydrogel's surface with precisely predefinable dimensions. The behavior can be modeled with the Flory-Huggins theory assuming a concentration-dependent polymer-solvent interaction parameter. Additionally, activation of the hydrogels by electrophilic oxirane groups creates reactive sites that will enable the later grafting of the hydrogel's surface with various specific nucleophiles, e.g. biomolecules. Thus, these hydrogels are particularly suitable as biomaterials for systematic investigations of cellular response to surface topography and elasticity of the substrate, both in vivo and in vitro.

MR imaging of the temporomandibular joint: comparison between acquisitions at 7.0 T using dielectric pads and 3.0 T.

OBJECTIVES: To qualitatively and quantitatively compare MRI of the temporomandibular joint (TMJ) at 7.0 T using high-permittivity dielectric pads and 3.0 T using a clinical high-resolution protocol. METHODS: Institutional review board-approved study with written informed consent. 12 asymptomatic volunteers were imaged at 7.0 and 3.0 T using 32-channel head coils. High-permittivity dielectric pads consisting of barium titanate in deuterated suspension were used for imaging at 7.0 T. Imaging protocol consisted of oblique sagittal proton density weighted turbo spin echo sequences. For quantitative analysis, pixelwise signal-to-noise ratio maps of the TMJ were calculated. For qualitative analysis, images were evaluated by two independent readers using 5-point Likert scales. Quantitative and qualitative results were compared using t-tests and Wilcoxon signed-rank tests, respectively. RESULTS: TMJ imaging at 7.0 T using high-permittivity dielectric pads was feasible in all volunteers. Quantitative analysis showed similar signal-to-noise ratio for both field strengths (mean ± SD; 7.0 T, 13.02 ± 3.92; 3.0 T, 14.02 ± 3.41; two-sample t-tests, p = 0.188). At 7.0 T, qualitative analysis yielded better visibility of all anatomical subregions of the temporomandibular disc (anterior band, intermediate zone and posterior band) than 3.0 T (Wilcoxon signed-rank tests, p < 0.05, corrected for multiple comparisons). CONCLUSIONS: MRI of the TMJ at 7.0 T using high-permittivity dielectric pads yields superior visibility of the temporomandibular disc compared with 3.0 T.