Severe Asthma Network Italy Definition of Clinical Remission in Severe Asthma: A Delphi Consensus

Severe asthma affects about 10% of the population with asthma and is characterized by low lung function and a high count of blood leukocytes, mainly eosinophils. Various definitions are used in clinical practice and in the literature to identify asthma remission: clinical remission, inflammatory remission, and complete remission. This work highlights a consensus for asthma remission using a Delphi method. In the context of the Severe Asthma Network Italy, which accounts for 57 severe asthma centers and more than 2,200 patients, a board of six experts drafted a list of candidate statements in a questionnaire, which has been revised to minimize redundancies and ensure clear and consistent wording for the first round (R1) of the analysis. Thirty-two statements were included in the R1 questionnaire and then submitted to a panel of 80 experts, which used a 5-point Likert scale to measure agreement regarding each statement. Then, an interim analysis of R1 data was performed, and items were discussed and considered to produce a consistent questionnaire for round 2 (R2) of the analysis. Then, the board set the R2 questionnaire, which included only important topics. Panelists were asked to vote on the statements in the R2 questionnaire afterward. During R2, the criteria of complete clinical remission (the absence of the need for oral corticosteroids, symptoms, exacerbations or attacks, and pulmonary function stability) and those of partial clinical remission (the absence of the need for oral corticosteroids, and two of three criteria: the absence of symptoms, exacerbations or attacks, and pulmonary stability) were confirmed. This Severe Asthma Network Italy Delphi analysis defined a valuable and independent tool that is easy to use, to test the efficacy of different treatments in patients with severe asthma enrolled into the SANI registry.

Understanding the Importance of Capsules in Dry Powder Inhalers

Pulmonary drug delivery is currently the focus of research and development because of its potential to produce maximum therapeutic benefit to patients by directing the drug straight to the lung disease site. Among all the available delivery options, one popular, proven and convenient inhaler device is the capsule-based dry powder inhaler (cDPI) for the treatment of an increasingly diverse range of diseases. cDPIs use a hard capsule that contains a powder formulation which consists of a mixture of a micronized drug and a carrier usually the lactose, known for its good lung tolerance. The capsule is either inserted into the device during manufacturer or by the patient prior to use. After perforating, opening or cut the capsule in the device, patients take a deep and rapid breath to inhale the powder, using air as the vector of drug displacement. The system is simple, relatively cheap and characterized by a lower carbon footprint than that of pressurized metered dose inhalers. This article reviews cDPI technology, focusing particularly on the importance of capsule characteristics and their function as a drug reservoir in cDPIs.

Flow injection analysis with diode array absorbance detection and dynamic surface tension detection for studying denaturation and surface activity of globular proteins

In this article, a multidimensional dynamic surface tension detector (DSTD), in a parallel configuration with a UV-visible diode array absorbance detector, is presented in a novel flow injection analysis (FIA) application to study the effects of chemical denaturants urea, guanidinium hydrochloride (GdmHCl), and guanidinium thyocyanate (GdmSCN) on the surface activity of globular proteins at the liquid-air interface. The DSTD signal is obtained by measuring the changing pressure across the liquid-air interface of 4-mul drops repeatedly forming at the end of a capillary using FIA. The sensitivity and selectivity of the DSTD signal is related to the surface-active protein concentration in aqueous solution combined with the thermodynamics and kinetics of protein interaction at a liquid-air drop interface. Rapid on-line calibration and measurement of dynamic surface tension is applied, with the surface tension converted into surface pressure results. Continuous surface tension measurement throughout the entire drop growth is achieved, providing insight into kinetic behavior of protein interactive processes at the liquid-air drop interface. Specifically, chemical denaturation of 12 commercial globular proteins-chicken egg albumin, bovine serum albumin, human serum albumin, alpha-lactalbumin (alpha-Lac), myoglobin, cytochrome c, hemoglobin, carbonic anhydrase, alpha-chymotrypsinogen A, beta-lactoglobulin (beta-LG), lysozyme, and glyceraldehyde-3-phosphate-dehydrogenase-is studied in terms of surface pressure (i.e., surface activity) after treatment with increasing concentrations of urea, GdmHCl, and GdmSCN in the 0-8, 0-6, and 0-5 M ranges, respectively. For several of these proteins, the spectroscopic absorbance changes are monitored simultaneously to provide additional information prior to drop formation. Results show that surface pressure of proteins generally increases as the denaturant concentration increases and that effectiveness is GdmSCN > GdmHCl > urea. Protein unfolding curves obtained by plotting surface pressure as a function of denaturant concentration are presented and compared with respect to unfolding curves obtained by using UV absorbance and literature data. Kinetic information relative to the protein adsorption to the air-liquid interface of two proteins, alpha-Lac and beta-LG (chosen as representative proteins for comparison), denatured by the three denaturants is also studied and discussed.

High-Throughput Screening of Protein Surface Activity via Flow Injection Analysis-pH Gradient-Dynamic Surface Tension Detection

Using flow injection analysis (FIA), a pH gradient is blended in real time with a protein sample as the pH-dependent protein surface activity is measured by a dynamic surface tension detector (FIA-pH-DSTD). This instrumental system was developed as a high-throughput method for the screening of protein surface activity at the air/liquid interface as a function of pH. This method utilizes the continuous flow, drop-based dynamic surface tension detector in combination with flow injection sample introduction and blending of a steady-state concentration of protein sample with a pH gradient ranging from pH 2.0 to pH 11.5. Dynamic surface tension is measured through the differential pressure across the air/liquid interface of repeatedly growing and detaching drops. Continuous surface tension measurement is achieved for each eluting drop of 2-s length (2 muL), providing insight into both the kinetic and thermodynamic behaviors of molecular orientation processes at the liquid/air interface. Three-dimensional data are obtained, with surface tension first converted to surface pressure, which is collected as a function of elution time versus drop time. In FIA-pH-DSTD, a commercial pH probe is used to measure pH during elution time, enabling surface pressure throughout drop time to be subsequently plotted as a function of eluting pH. An automated DSTD calibration procedure and data analysis method is applied, which allows simultaneous use of two different solvents, permitting real-time dynamic surface tension data to be obtained. The method was applied to the analysis of 14 commercial purified proteins, yielding characteristic features of surface activity as a function of pH. The reproducibility of the measurement and selectivity advantage of the DSTD was shown for the analysis of serum albumins from various mammalian sources. Several applications were also suggested and discussed in order to show the potential of the method for protein and food chemistry studies and in the study of protein-polymer interactions.