Economic Evaluation of Tobramycin Inhalation Powder for the Treatment of Chronic Pulmonary Pseudomonas aeruginosa Infection in Patients with Cystic Fibrosis.

Clin Drug Investig. 2017 Jun 22;:

Authors: Panguluri S, Gunda P, Debonnett L, Hamed K

Abstract
BACKGROUND: Chronic lung infection with Pseudomonas aeruginosa occurs in approximately 50% of patients with cystic fibrosis (CF). This infection further compromises lung function, and significantly contributes to the increased healthcare costs.
OBJECTIVES: Inhaled tobramycin, used to manage P. aeruginosa infection in CF patients, is available as powder (tobramycin inhalation powder, TIP) and solution (tobramycin inhalation solution, TIS). Evidence suggests increased adherence with the use of TIP over TIS. Hence, this analysis aimed to evaluate the potential pharmacoeconomic benefit of increased adherence with TIP over TIS in the US setting.
METHODS: A patient-level simulation model was developed to compare TIP with TIS. Both costs and benefits were predicted over a 10-year time horizon from a payer's perspective, and were discounted annually at 3%. All costs were presented in 2016 US dollars.
RESULTS: TIP was associated with greater quality-adjusted life-years (by 0.27) and lower total costs (by US$36,168) as compared with TIS over a 10-year time horizon. TIP-treated patients experienced a decreased mean number of exacerbations than TIS-treated patients (39.24 vs 50.20). Furthermore, administration of TIP via the T-326 Inhaler was associated with significant cost savings per patient, because of the nebulizer required for administering TIS (by US$1596) and exacerbation costs (by US$76,531). Probabilistic sensitivity analysis showed that TIP was dominant over TIS in 100% of the simulations.
CONCLUSION: TIP is likely to be a more cost-effective treatment than TIS, and therefore may reduce the economic burden of CF.

PMID: 28643178 [PubMed - as supplied by publisher]

Structure of O-Antigen and Hybrid Biosynthetic Locus in Burkholderia cenocepacia Clonal Variants Recovered from a Cystic Fibrosis Patient.

Front Microbiol. 2017;8:1027

Authors: Hassan AA, Maldonado RF, Dos Santos SC, Di Lorenzo F, Silipo A, Coutinho CP, Cooper VS, Molinaro A, Valvano MA, Sá-Correia I

Abstract
Burkholderia cenocepacia is an opportunistic pathogen associated with chronic lung infections and increased risk of death in patients with cystic fibrosis (CF). In this work, we investigated the lipopolysaccharide (LPS) of clinical variants of B. cenocepacia that were collected from a CF patient over a period of 3.5 years, from the onset of infection until death by necrotizing pneumonia (cepacia syndrome). We report the chemical structure of the LPS molecule of various sequential isolates and the identification of a novel hybrid O-antigen (OAg) biosynthetic cluster. The OAg repeating unit of the LPS from IST439, the initial isolate, is a [→2)-β-D-Ribf-(1→4)-α-D-GalpNAc-(1→] disaccharide, which was not previously described in B. cenocepacia. The IST439 OAg biosynthetic gene cluster contains 7 of 23 genes that are closely homologous to genes found in B. multivorans, another member of the Burkholderia cepacia complex. None of the subsequent isolates expressed OAg. Genomic sequencing of these isolates enabled the identification of mutations within the OAg cluster, but none of these mutations could be associated with the loss of OAg. This study provides support to the notion that OAg LPS modifications are an important factor in the adaptation of B. cenocepacia to chronic infection and that the heterogeneity of OAgs relates to variation within the OAg gene cluster, indicating that the gene cluster might have been assembled through multiple horizontal transmission events.

PMID: 28642745 [PubMed - in process]

Cellular distribution and function of ion channels involved in transport processes in rat tracheal epithelium.

Physiol Rep. 2017 Jun;5(12):

Authors: Hahn A, Faulhaber J, Srisawang L, Stortz A, Salomon JJ, Mall MA, Frings S, Möhrlen F

Abstract
Transport of water and electrolytes in airway epithelia involves chloride-selective ion channels, which are controlled either by cytosolic Ca(2+) or by cAMP The contributions of the two pathways to chloride transport differ among vertebrate species. Because rats are becoming more important as animal model for cystic fibrosis, we have examined how Ca(2+)- dependent and cAMP- dependent Cl(-) secretion is organized in the rat tracheal epithelium. We examined the expression of the Ca(2+)-gated Cl(-) channel anoctamin 1 (ANO1), the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel, the epithelial Na(+) channel ENaC, and the water channel aquaporin 5 (AQP5) in rat tracheal epithelium. The contribution of ANO1 channels to nucleotide-stimulated Cl(-) secretion was determined using the channel blocker Ani9 in short-circuit current recordings obtained from primary cultures of rat tracheal epithelial cells in Ussing chambers. We found that ANO1, CFTR and AQP5 proteins were expressed in nonciliated cells of the tracheal epithelium, whereas ENaC was expressed in ciliated cells. Among nonciliated cells, ANO1 occurred together with CFTR and Muc5b and, in addition, in a different cell type without CFTR and Muc5b. Bioelectrical studies with the ANO1-blocker Ani9 indicated that ANO1 mediated the secretory response to the nucleotide uridine-5'-triphosphate. Our data demonstrate that, in rat tracheal epithelium, Cl(-) secretion and Na(+) absorption are routed through different cell types, and that ANO1 channels form the molecular basis of Ca(2+)-dependent Cl(-) secretion in this tissue. These characteristic features of Cl(-)-dependent secretion reveal similarities and distinct differences to secretory processes in human airways.

PMID: 28642338 [PubMed - in process]

Cystic fibrosis: Current aspects and perspectives.

Presse Med. 2017 Jun;46(6 Pt 2):e85-e86

Authors: Burgel PR, Fajac I

PMID: 28641709 [PubMed - in process]

Transmembrane helical interactions in the CFTR channel pore.

PLoS Comput Biol. 2017 Jun 22;13(6):e1005594

Authors: Das J, Aleksandrov AA, Cui L, He L, Riordan JR, Dokholyan NV

Abstract
Mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene affect CFTR protein biogenesis or its function as a chloride channel, resulting in dysregulation of epithelial fluid transport in the lung, pancreas and other organs in cystic fibrosis (CF). Development of pharmaceutical strategies to treat CF requires understanding of the mechanisms underlying channel function. However, incomplete 3D structural information on the unique ABC ion channel, CFTR, hinders elucidation of its functional mechanism and correction of cystic fibrosis causing mutants. Several CFTR homology models have been developed using bacterial ABC transporters as templates but these have low sequence similarity to CFTR and are not ion channels. Here, we refine an earlier model in an outward (OWF) and develop an inward (IWF) facing model employing an integrated experimental-molecular dynamics simulation (200 ns) approach. Our IWF structure agrees well with a recently solved cryo-EM structure of a CFTR IWF state. We utilize cysteine cross-linking to verify positions and orientations of residues within trans-membrane helices (TMHs) of the OWF conformation and to reconstruct a physiologically relevant pore structure. Comparison of pore profiles of the two conformations reveal a radius sufficient to permit passage of hydrated Cl- ions in the OWF but not the IWF model. To identify structural determinants that distinguish the two conformations and possible rearrangements of TMHs within them responsible for channel gating, we perform cross-linking by bifunctional reagents of multiple predicted pairs of cysteines in TMH 6 and 12 and 6 and 9. To determine whether the effects of cross-linking on gating observed are the result of switching of the channel from open to close state, we also treat the same residue pairs with monofunctional reagents in separate experiments. Both types of reagents prevent ion currents indicating that pore blockage is primarily responsible.

PMID: 28640808 [PubMed - as supplied by publisher]

Multisystem Imaging Findings of Cystic Fibrosis in Adults: Recognizing Typical and Atypical Patterns of Disease.

AJR Am J Roentgenol. 2017 Jul;209(1):3-18

Authors: Averill S, Lubner MG, Menias CO, Bhalla S, Mellnick VM, Kennedy TA, Pickhardt PJ

Abstract
OBJECTIVE: There is an expanding and increasingly heterogeneous population of adult patients with cystic fibrosis (CF). Although CF is usually diagnosed in children with progressive multisystem involvement, up to 7% of CF cases are currently diagnosed de novo in adults with subtle manifestations distinct from the typical features of classic CF. The purpose of this article is to present the wide spectrum of CF in adults, including both classic and nonclassic variants, with an emphasis on the nonclassic imaging findings.
CONCLUSION: Recurrent pancreatitis, chronic sinusitis, and congenital bilateral absence of the vas deferens (CBAVD) are several of the ways in which CF is identified in adult patients with relatively rare mutations and with overall milder manifestations. It is important for radiologists to recognize the wide spectrum of CF to optimally monitor disease progression and response to therapeutic interventions in distinct adult patient populations.

PMID: 28639921 [PubMed - in process]

Enzymatic Mechanisms Involved in Evasion of Fungi to the Oxidative Stress: Focus on Scedosporium apiospermum.

Mycopathologia. 2017 Jun 21;:

Authors: Staerck C, Vandeputte P, Gastebois A, Calenda A, Giraud S, Papon N, Bouchara JP, Fleury MJJ

Abstract
The airways of patients with cystic fibrosis (CF) are frequently colonized by various filamentous fungi, mainly Aspergillus fumigatus and Scedosporium species. To establish within the respiratory tract and cause an infection, these opportunistic fungi express pathogenic factors allowing adherence to the host tissues, uptake of extracellular iron, or evasion to the host immune response. During the colonization process, inhaled conidia and the subsequent hyphae are exposed to reactive oxygen species (ROS) and reactive nitrogen species (RNS) released by phagocytic cells, which cause in the fungal cells an oxidative stress and a nitrosative stress, respectively. To cope with these constraints, fungal pathogens have developed various mechanisms that protect the fungus against ROS and RNS, including enzymatic antioxidant systems. In this review, we summarize the different works performed on ROS- and RNS-detoxifying enzymes in fungi commonly encountered in the airways of CF patients and highlight their role in pathogenesis of the airway colonization or respiratory infections. The potential of these enzymes as serodiagnostic tools is also emphasized. In addition, taking advantage of the recent availability of the whole genome sequence of S. apiospermum, we identified the various genes encoding ROS- and RNS-detoxifying enzymes, which pave the way for future investigations on the role of these enzymes in pathogenesis of these emerging species since they may constitute new therapeutics targets.

PMID: 28639066 [PubMed - as supplied by publisher]

Inflammation and Oxidation Biomarkers in Patients with Cystic Fibrosis: The Influence of Azithromycin.

Eurasian J Med. 2017 Jun;49(2):118-123

Authors: Olveira C, Padilla A, Dorado A, Contreras V, Garcia-Fuentes E, Rubio-Martin E, Porras N, Doña E, Carmona A, Olveira G

Abstract
OBJECTIVE: In addition to their antibiotic effect, macrolides appear to modulate the inflammatory response in cystic fibrosis (CF) and could influence oxidative stress. The objective of this study was to assess oxidation biomarkers and levels of inflammation and to determine whether there is an association between these parameters and the intake of macrolides.
MATERIALS AND METHODS: The subjects included in this cross-sectional study were, on the one hand, clinically stable patients with CF and, on the other, healthy controls. The following serum and plasma inflammatory and oxidative stress biomarkers were measured: interleukin-6 (IL-6), reactive C protein (RCP), tumor necrosis alpha (TNF-α), glutathione peroxidase (GPx), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD), together with markers of lipid peroxidation (8-isoprostanes and thiobarbituric acid reactive substances [TBARS]). Clinical, anthropometric, lung function, radiological, and analytical variables (albumin, prealbumin, vitamins, and zinc) were also recorded.
RESULTS: We studied 36 adults with CF and 41 controls. No differences were observed in age, gender, or anthropometric variables. The patients had significantly higher levels of IL-6, TNF-α, RCP, TBARS, and isoprostanes, and lower levels of SOD than the controls. Twenty-three of the patients were treated with azithromycin, and they had more severe clinical and radiological parameters than those who were not but nevertheless presented significantly lower levels of TNF-α. No differences were observed in the markers of oxidation.
CONCLUSION: Inflammation and oxidation biomarkers were increased in patients with CF compared with controls. The use of azithromycin was associated with reduced TNF-α levels and did not influence oxidation parameters.

PMID: 28638254 [PubMed - in process]

Dietary Salt Exacerbates Experimental Colitis.

J Immunol. 2017 Jun 21;:

Authors: Tubbs AL, Liu B, Rogers TD, Sartor RB, Miao EA

Abstract
The Western diet is characterized by high protein, sugar, fat, and low fiber intake, and is widely believed to contribute to the incidence and pathogenesis of inflammatory bowel disease (IBD). However, high sodium chloride salt content, a defining feature of processed foods, has not been considered as a possible environmental factor that might drive IBD. We set out to bridge this gap. We examined murine models of colitis on either a high salt diet (HSD) or a low salt diet. We demonstrate that an HSD exacerbates inflammatory pathology in the IL-10-deficient murine model of colitis relative to mice fed a low salt diet. This was correlated with enhanced expression of numerous proinflammatory cytokines. Surprisingly, sodium accumulated in the colons of mice on an HSD, suggesting a direct effect of salt within the colon. Similar to the IL-10-deficient model, an HSD also enhanced cytokine expression during infection by Salmonella typhimurium This occurred in the first 3 d of infection, suggesting that an HSD potentiates an innate immune response. Indeed, in cultured dendritic cells we found that high salt media potentiates cytokine expression downstream of TLR4 activation via p38 MAPK and SGK1. A third common colitis model, administration of dextran sodium sulfate, was hopelessly confounded by the high sodium content of the dextran sodium sulfate. Our results raise the possibility that high dietary salt is an environmental factor that drives increased inflammation in IBD.

PMID: 28637899 [PubMed - as supplied by publisher]

Modeling and Simulation of Mucus Flow in Human Bronchial Epithelial Cell Cultures - Part I: Idealized Axisymmetric Swirling Flow.

PLoS Comput Biol. 2016 Aug;12(8):e1004872

Authors: Vasquez PA, Jin Y, Palmer E, Hill D, Forest MG

Abstract
A multi-mode nonlinear constitutive model for mucus is constructed directly from micro- and macro-rheology experimental data on cell culture mucus, and a numerical algorithm is developed for the culture geometry and idealized cilia driving conditions. This study investigates the roles that mucus rheology, wall effects, and HBE culture geometry play in the development of flow profiles and the shape of the air-mucus interface. Simulations show that viscoelasticity captures normal stress generation in shear leading to a peak in the air-mucus interface at the middle of the culture and a depression at the walls. Linear and nonlinear viscoelastic regimes can be observed in cultures by varying the hurricane radius and mean rotational velocity. The advection-diffusion of a drug concentration dropped at the surface of the mucus flow is simulated as a function of Peclet number.

PMID: 27494700 [PubMed - indexed for MEDLINE]

Lentiviral Vector Gene Therapy Protects XCGD Mice From Acute Staphylococcus aureus Pneumonia and Inflammatory Response.

Mol Ther. 2016 Oct;24(10):1873-1880

Authors: Farinelli G, Jofra Hernandez R, Rossi A, Ranucci S, Sanvito F, Migliavacca M, Brombin C, Pramov A, Di Serio C, Bovolenta C, Gentner B, Bragonzi A, Aiuti A

Abstract
Chronic granulomatous disease (CGD) is a primary immunodeficiency due to a deficiency in one of the subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. CGD patients are characterized by an increased susceptibility to bacterial and fungal infections, and to granuloma formation due to the excessive inflammatory responses. Several gene therapy approaches with lentiviral vectors have been proposed but there is a lack of in vivo data on the ability to control infections and inflammation. We set up a mouse model of acute infection that closely mimic the airway infection in CGD patients. It involved an intratracheal injection of a methicillin-sensitive reference strain of S. aureus. Gene therapy, with hematopoietic stem cells transduced with regulated lentiviral vectors, restored the functional activity of NADPH oxidase complex (with 20-98% of dihydrorhodamine positive granulocytes and monocytes) and saved mice from death caused by S. aureus, significantly reducing the bacterial load and lung damage, similarly to WT mice even at low vector copy number. When challenged, gene therapy-treated XCGD mice showed correction of proinflammatory cytokines and chemokine imbalance at levels that were comparable to WT. Examined together, our results support the clinical development of gene therapy protocols using lentiviral vectors for the protection against infections and inflammation.

PMID: 27456061 [PubMed - indexed for MEDLINE]

ATS-NHLBI Asthma COPD Overlap (ACO) Workshop Report.

Am J Respir Crit Care Med. 2017 Jun 21;:

Authors: Woodruff PG, van den Berge M, Boucher RC, Brightling C, Burchard EG, Christenson SA, Han MK, Holtzman MJ, Kraft M, Lynch DA, Martinez FD, Reddel HK, Sin DD, Washko GR, Wenzel SE, Punturieri A, Freemer MM, Wise RA

Abstract
Asthma and COPD are highly prevalent chronic obstructive lung diseases with an associated high burden of disease. Asthma, which is often allergic in origin, frequently begins in infancy or childhood with variable airflow obstruction and intermittent wheezing, cough, and dyspnea. Patients with COPD, in contrast, are usually current or former smokers who present after the age of 40 years with symptoms (often persistent), including dyspnea and a productive cough. Based on age and smoking history, it is often easy to distinguish between asthma and COPD. However, some patients have features compatible with both diseases. Because clinical studies typically exclude these patients, their underlying disease mechanisms and appropriate treatment remain largely uncertain. To explore the status of and opportunities for research in this area, the National Heart, Lung, and Blood Institute (NHLBI) in partnership with the American Thoracic Society (ATS) convened a workshop of investigators in San Francisco (CA) on May 14, 2016. At the workshop, current understanding of Asthma-COPD overlap was discussed among clinicians, pathologists, radiologists, epidemiologists, and investigators with expertise in asthma and COPD. They considered knowledge gaps in our understanding of Asthma-COPD overlap and identified strategies and research priorities that will advance its understanding. This report summarizes those discussions.

PMID: 28636425 [PubMed - as supplied by publisher]

On the importance of accurate quantification of individual volatile metabolites in exhaled breath.

J Breath Res. 2017 Jun 21;:

Authors: Smith D, Spanel P

Abstract
It is argued that shortcomings of certain approaches to breath analysis research based on superficial interpretation of non-quantitative data are inadvertently inhibiting the progression of non-invasive breath analysis into clinical practice. The objective of this perspective is to suggest more clinically profitable approaches to breath research. Thus, following a discourse on the challenges and expectations in breath research, a brief indication is given of the analytical techniques currently used for the analysis of very humid exhaled breath. The seminal work that has been carried out using GC-MS revealed that exhaled breath comprises large numbers of trace volatile organic compounds, VOCs. Unfortunately, analysis of these valuable GC-MS data is mostly performed using chemometrics to distinguish the VOC content of breath samples collected from patients and healthy controls, and reliable quantification of the VOCs is rarely deemed necessary. This limited approach ignores the requirements of clinically acceptable biomarkers and misses the opportunity to identify relationships between the concentrations of individual VOCs and certain related physiological or metabolic parameters. Therefore, a plea is made for more effort to be directed towards the positive identification and accurate quantification of individual VOCs in exhaled breath, which are more physiologically meaningful as best exemplified by the quantification of breath nitric oxide, NO. Support for the value of individual VOC quantification is illustrated by the SIFT-MS studies of breath hydrogen cyanide, HCN, a biomarker of Pseudomonas aeruginosa infection, breath acetic acid as an indicator of airways acidification in cystic fibrosis patients, and n-pentane as a breath biomarker of inflammation in idiopathic bowel disease patients. These single VOCs could be used as non-invasive monitors of the efficacy of therapeutic intervention. The increase of breath methanol following the ingestion of a known amount of the sweetener aspartame impressively shows that accurate breath analysis is a reliable indicator of blood.

PMID: 28635619 [PubMed - as supplied by publisher]

Heparin: new life for an old drug.

Nanomedicine (Lond). 2017 Jun 21;:

Authors: Aláez-Versón CR, Lantero E, Fernàndez-Busquets X

Abstract
Heparin is one of the oldest drugs, which nevertheless remains in widespread clinical use as an inhibitor of blood coagulation. The history of its identification a century ago unfolded amid one of the most fascinating scientific controversies turning around the distribution of credit for its discovery. The composition, purification and structure-function relationship of this naturally occurring glycosaminoglycan regarding its classical role as anticoagulant will be dealt with before proceeding to discuss its therapeutic potential in, among other, inflammatory and infectious disease, cancer treatment, cystic fibrosis and Alzheimer's disease. The first bibliographic reference hit using the words 'nanomedicine' and 'heparin' is as recent as 2008. Since then, nanomedical applications of heparin have experienced an exponential growth that will be discussed in detail, with particular emphasis on its antimalarial activity. Some of the most intriguing potential applications of heparin nanomedicines will be exposed, such as those contemplating the delivery of drugs to the mosquito stages of malaria parasites.

PMID: 28635544 [PubMed - as supplied by publisher]

Psl Produced by Mucoid Pseudomonas aeruginosa Contributes to the Establishment of Biofilms and Immune Evasion.

MBio. 2017 Jun 20;8(3):

Authors: Jones CJ, Wozniak DJ

Abstract
Despite years of research and clinical advances, chronic pulmonary infections with mucoid Pseudomonas aeruginosa remain the primary concern for cystic fibrosis patients. Much of the research on these strains has focused on the contributions of the polysaccharide alginate; however, it is becoming evident that the neutral polysaccharide Psl also contributes to biofilm formation and the maintenance of chronic infections. Here, we demonstrate that Psl produced by mucoid strains has significant roles in biofilm structure and evasion of immune effectors. Though mucoid strains produce less Psl than nonmucoid strains, the Psl that is produced is functional, since it mediates adhesion to human airway cells and epithelial cell death. Additionally, Psl protects mucoid bacteria from opsonization and killing by complement components in human serum. Psl production by mucoid strains stimulates a proinflammatory response in the murine lung, leading to reduced colonization. To determine the relevance of these data to clinical infections, we tested Psl production and biofilm formation of a panel of mucoid clinical isolates. We demonstrated three classes of mucoid isolates, those that produce Psl and form robust biofilms, those that did not produce Psl and have a poor biofilm phenotype, and exopolysaccharide (EPS) redundant strains. Collectively, these experimental results demonstrate that Psl contributes to the biofilm formation and immune evasion of many mucoid strains. This is a novel role for Psl in the establishment and maintenance of chronic pulmonary infections by mucoid strains.IMPORTANCE Cystic fibrosis patients are engaged in an ongoing battle against chronic lung infections by the bacterium Pseudomonas aeruginosa One key factor contributing to the maintenance of chronic infections is the conversion to a mucoid phenotype, where the bacteria produce copious amounts of the polysaccharide alginate. Once the bacteria become mucoid, existing treatments are poorly effective. We proposed that mucoid bacteria produce an additional polysaccharide, Psl, which is important for their establishment and maintenance of chronic infections. This work demonstrates that Psl enhances attachment of mucoid bacteria to lung surfaces and leads to inflammation and damage in the lung. Additionally, we find that 50% of mucoid bacteria isolated from patients with chronic infections rely on Psl for the structure of their biofilm communities, suggesting that treatments against Psl should be investigated to enhance the success of current therapies.

PMID: 28634241 [PubMed - in process]

A Comparison of 2 Respiratory Devices for Sputum Clearance in Adults With Non-Cystic Fibrosis Bronchiectasis.

Respir Care. 2017 Jun 20;:

Authors: Silva YR, Greer TA, Morgan LC, Li F, Farah CS

Abstract
BACKGROUND: Airway clearance techniques are a vital part of routine care for patients with bronchiectasis. There is no clear superior modality. The Flutter combines oscillations (6-20Hz) and positive expiratory pressure; the Lung Flute combines positive expiratory pressure and low frequency acoustic waves (18-22Hz), to augment clearance. This project aimed to compare these devices.
METHODS: This was a randomized crossover study of adult subjects with stable non-cystic fibrosis bronchiectasis (expectorating >25 mL/d). Subjects attended 2 separate out-patient visits, 1 week apart, and completed a supervised sputum clearance regime and Lickert scale (8 questions regarding subjects' perception of the experience using each device). Total sputum expectorated during supervised intervention (T1) and after 30 min from the end of T1 (T2) was recorded as wet sputum weight. Total wet sputum weight desiccated in a microwave (10 min at 300 watts), allowed measurement of total dry sputum weight. Data were compared using paired t test.
RESULTS: We recruited 40 subjects with a mean ± SD age of 63 ± 16y. Overall, there was no significant difference in wet sputum weight (Flutter, 5.78 ± 6.47 g; Lung Flute, 5.75 ± 0.22g) and dry sputum weight (Flutter, 0.40 ± 0.86g; Lung Flute, 0.22 ± 0.21g). At T1, wet sputum weight was higher for the Flutter (5.10 ± 6.26g) compared with the Lung Flute (3.74 ± 3.44g) (P = .038). At T2, wet sputum weight was higher for the Lung Flute (2.02 ± 3.01g) compared with the Flutter (0.68 ± 0.75g) (P = .001). Subjects perceived the Flutter as being significantly better at clearing secretions (P = .01), easy to understand (P = .03), and simple to use (P = .01) compared with the Lung Flute.
CONCLUSIONS: Both devices were well-tolerated and successfully augmented secretion clearance. Most subjects preferred the Flutter because of increased speed of secretion clearance, and greater ease of use.

PMID: 28634173 [PubMed - as supplied by publisher]

Population Pharmacokinetics of Tobramycin Inhalation Solution in Pediatric Patients with Cystic Fibrosis.

J Pharm Sci. 2017 Jun 17;:

Authors: Wang X, Koehne-Voss S, Anumolu SS, Yu J

Abstract
Tobramycin inhalation solution (TOBI) given as a twice-daily inhalation of nebulized aerosols of 300 mg is approved for the treatment of Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients over 6 years of age. To investigate tobramycin pharmacokinetics (PK) after inhalation of TOBI in pediatric CF patients below 7 years, a population PK approach was used to evaluate tobramycin PK data in patients 6 months to 44 years of age from four clinical studies. The final model used a two-compartmental, first-order absorption model with effect of body mass index on the apparent central volume of distribution. Relative bioavailability in patients between 6 months and 7 years increased with age by a linear relationship, and was modeled as a ratio to that of patients over 7 years. Simulation showed steady-state concentrations of tobramycin are lower in pediatric patients 6 months to 6 years than those in patients over 6 years. However, systemic exposure is not predictive of clinical efficacy due to direct dosing at the infection site. Pseudomonas aeruginosa eradication rate and safety profile in patients less than 7 years of age were similar to patients older than 6 years, therefore no dose adjustment is warranted in the younger pediatric patients.

PMID: 28634121 [PubMed - as supplied by publisher]

Identification of intestinal ion transport defects in microvillus inclusion disease.

Am J Physiol Gastrointest Liver Physiol. 2016 Jul 01;311(1):G142-55

Authors: Kravtsov DV, Ahsan MK, Kumari V, van Ijzendoorn SC, Reyes-Mugica M, Kumar A, Gujral T, Dudeja PK, Ameen NA

Abstract
Loss of function mutations in the actin motor myosin Vb (Myo5b) lead to microvillus inclusion disease (MVID) and death in newborns and children. MVID results in secretory diarrhea, brush border (BB) defects, villus atrophy, and microvillus inclusions (MVIs) in enterocytes. How loss of Myo5b results in increased stool loss of chloride (Cl(-)) and sodium (Na(+)) is unknown. The present study used Myo5b loss-of-function human MVID intestine, polarized intestinal cell models of secretory crypt (T84) and villus resembling (CaCo2BBe, C2BBe) enterocytes lacking Myo5b in conjunction with immunofluorescence confocal stimulated emission depletion (gSTED) imaging, immunohistochemical staining, transmission electron microscopy, shRNA silencing, immunoblots, and electrophysiological approaches to examine the distribution, expression, and function of the major BB ion transporters NHE3 (Na(+)), CFTR (Cl(-)), and SLC26A3 (DRA) (Cl(-)/HCO3 (-)) that control intestinal fluid transport. We hypothesized that enterocyte maturation defects lead villus atrophy with immature secretory cryptlike enterocytes in the MVID epithelium. We investigated the role of Myo5b in enterocyte maturation. NHE3 and DRA localization and function were markedly reduced on the BB membrane of human MVID enterocytes and Myo5bKD C2BBe cells, while CFTR localization was preserved. Forskolin-stimulated CFTR ion transport in Myo5bKD T84 cells resembled that of control. Loss of Myo5b led to YAP1 nuclear retention, retarded enterocyte maturation, and a cryptlike phenotype. We conclude that preservation of functional CFTR in immature enterocytes, reduced functional expression of NHE3, and DRA contribute to Cl(-) and Na(+) stool loss in MVID diarrhea.

PMID: 27229121 [PubMed - indexed for MEDLINE]

Multi-electrode system for measurement of transmembrane ion-fluxes through living epithelial cells.

Bioelectrochemistry. 2017 Jun 13;117:65-73

Authors: Zając M, Lewenstam A, Dolowy K

Abstract
Cystic Fibrosis (CF) is the most common fatal human genetic disease. It is caused by the defect in a single anion channel protein which affects ion and water transport across the epithelial tissue. A flat multi-electrode platform of diameter 12mm, allowing for measurement of four ions: sodium, potassium, hydrogen and chloride by exchangeable/replaceable ion-selective electrodes is described. The measurement is possible owing to the architecture of the platform which accommodates all the electrodes and inlets/outlets. The platform fits to the cup and operates in a small volume of the solution bathing the living epithelial cell layer (membrane) deposited on a porous support of the cup, which allows for effective monitoring of ion concentration changes. By applying two multi-electrode platforms, it is possible to measure the ion transmembrane fluxes. The inlet and outlet tubes in the platforms allow for on-fly change of the calibrants, ion-concentration changes and ion channel blockers. Using different ion-concentration gradients and blockers of ion-transporting molecules we show for the first time that sodium ions flow from the basolateral to apical face of the cell monolayer via a paracellular route and return also via a transcellular one, while chloride anions are transported back and forth exclusively via a transcellular route.

PMID: 28633068 [PubMed - as supplied by publisher]

Drug Hypersensitivity and Desensitizations: Mechanisms and New Approaches.

Int J Mol Sci. 2017 Jun 20;18(6):

Authors: de Las Vecillas Sánchez L, Alenazy LA, Garcia-Neuer M, Castells MC

Abstract
Drug hypersensitivity reactions (HSRs) are increasing in the 21st Century with the ever expanding availability of new therapeutic agents. Patients with cancer, chronic inflammatory diseases, cystic fibrosis, or diabetes can become allergic to their first line therapy after repeated exposures or through cross reactivity with environmental allergens. Avoidance of the offending allergenic drug may impact disease management, quality of life, and life expectancy. Precision medicine provides new tools for the understanding and management of hypersensitivity reactions (HSRs), as well as a personalized treatment approach for IgE (Immunoglobuline E) and non-IgE mediated HSRs with drug desensitization (DS). DS induces a temporary hyporesponsive state by incremental escalation of sub-optimal doses of the offending drug. In vitro models have shown evidence that IgE desensitization is an antigen-specific process which blocks calcium flux, impacts antigen/IgE/FcεRI complex internalization and prevents the acute and late phase reactions as well as mast cell mediator release. Through a "bench to bedside" approach, in vitro desensitization models help elucidate the molecular pathways involved in DS, providing new insights to improved desensitization protocols for all patients. The aim of this review is to summarize up to date information on the drug HSRs, the IgE mediated mechanisms of desensitization, and their clinical applications.

PMID: 28632196 [PubMed - in process]