Correction: Modulation of behaviour and virulence of a high alginate expressing Pseudomonas aeruginosa strain from cystic fibrosis by oral commensal bacterium Streptococcus anginosus.

PLoS One. 2017;12(4):e0176577

Authors: Waite RD, Qureshi MR, Whiley RA

Abstract
[This corrects the article DOI: 10.1371/journal.pone.0173741.].

PMID: 28426833 [PubMed - in process]

Hydroxyurea (hydroxycarbamide) for sickle cell disease.

Cochrane Database Syst Rev. 2017 Apr 20;4:CD002202

Authors: Nevitt SJ, Jones AP, Howard J

Abstract
BACKGROUND: Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea (hydroxycarbamide), an oral chemotherapeutic drug, ameliorates some of the clinical problems of SCD, in particular that of pain, by raising fetal haemoglobin. This is an update of a previously published Cochrane Review.
OBJECTIVES: To assess the effects of hydroxyurea therapy in people with SCD (all genotypes), of any age, regardless of setting.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries.Date of the most recent search: 16 January 2017.
SELECTION CRITERIA: Randomised and quasi-randomised controlled trials, of one month or longer, comparing hydroxyurea with placebo, standard therapy or other interventions for people with SCD.
DATA COLLECTION AND ANALYSIS: Authors independently assessed studies for inclusion, carried out data extraction and assessed the risk of bias.
MAIN RESULTS: Seventeen studies were identified in the searches; eight randomised controlled trials were included, recruiting 899 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sβºthalassaemia (HbSβºthal) genotypes). Studies lasted from six to 30 months.Four studies (577 adults and children with HbSS or HbSβºthal) compared hydroxyurea to placebo; three recruited individuals with only severe disease and one recruited individuals with all disease severities. There were statistically significant improvements in terms of pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use), measures of fetal haemoglobin and neutrophil counts and fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups. There were no consistent statistically significant differences in terms of quality of life and adverse events (including serious or life-threatening events). Seven deaths occurred during the studies, but the rates by treatment group were not statistically significantly different.Two studies (254 children with HbSS or HbSβºthal also with risk of primary or secondary stroke) compared hydroxyurea and phlebotomy to transfusion and chelation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts, but more occurrences of acute chest syndrome and infections in the hydroxyurea and phlebotomy group. There were no consistent statistically significant differences in terms of pain alteration and adverse events (including serious or life-threatening events). Two deaths occurred during the studies (one in a the hydroxyurea treatment arm and one in the control arm), but the rates by treatment group were not statistically significantly different. In the primary prevention study, no strokes occurred in either treatment group but in the secondary prevention study, seven strokes occurred in the hydroxyurea and phlebotomy group (none in the transfusion and chelation group) and the study was terminated early.The quality of the evidence for the above two comparisons was judged as moderate to low as the studies contributing to these comparisons were mostly large and well designed (and at low risk of bias); however evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events and results are applicable only to individuals with HbSS and HbSβºthal genotypes.Of the remaining two studies, one (22 children with HbSS or HbSβºthal also at risk of stoke) compared hydroxyurea to observation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts but no statistically significant differences in terms of adverse events (including serious or life-threatening events).The final study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea - there was statistically significant improvement in terms of measures of fetal haemoglobin, but no statistically significant differences in terms of adverse events (including serious or life-threatening events). No participants died in either of these studies and other outcomes relevant to the review were not reported.The quality of the evidence for the above two comparisons was judged to be very low due to the limited number of participants, the lack of statistical power (as both studies were terminated early with approximately only 20% of their target sample size recruited) and the lack of applicability to all age groups and genotypes.
AUTHORS' CONCLUSIONS: There is evidence to suggest that hydroxyurea is effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anaemia of HbSS or HbSβºthal genotypes and in preventing life-threatening neurological events in those with sickle cell anaemia at risk of primary stroke by maintaining transcranial doppler velocities. However, there is still insufficient evidence on the long-term benefits of hydroxyurea, particularly in preventing chronic complications of SCD, recommending a standard dose or dose escalation to maximum tolerated dose. There is also insufficient evidence about the long-term risks of hydroxyurea, including its effects on fertility and reproduction. Evidence is also limited on the effects of hydroxyurea on individuals with HbSC genotype. Future studies should be designed to address such uncertainties.

PMID: 28426137 [PubMed - as supplied by publisher]

Antimicrobial Activity of Mesenchymal Stem Cells: Current Status and New Perspectives of Antimicrobial Peptide-Based Therapies.

Front Immunol. 2017;8:339

Authors: Alcayaga-Miranda F, Cuenca J, Khoury M

Abstract
While mesenchymal stem cells (MSCs)-based therapy appears to be promising, there are concerns regarding possible side effects related to the unwanted suppression of antimicrobial immunity leading to an increased risk of infection. Conversely, recent data show that MSCs exert strong antimicrobial effects through indirect and direct mechanisms, partially mediated by the secretion of antimicrobial peptides and proteins (AMPs). In fact, MSCs have been reported to increase bacterial clearance in preclinical models of sepsis, acute respiratory distress syndrome, and cystic fibrosis-related infections. This article reviews the current evidence regarding the direct antimicrobial effector function of MSCs, focusing mainly on the role of MSCs-derived AMPs. The strategies that might modulate the expression and secretion of these AMPs, leading to enhanced antimicrobial effect, are highlighted. Furthermore, studies evaluating the presence of AMPs in the cargo of extracellular vesicles (EVs) are underlined as perspective opportunities to develop new drug delivery tools. The antimicrobial potential of MSCs-derived EVs can also be heightened through cell conditioning and/or drug loading. Finally, improving the pharmacokinetics and delivery, in addition to deciphering the multi-target drug status of AMPs, should synergistically lead to key advances against infections caused by drug-resistant strains.

PMID: 28424688 [PubMed - in process]

Objective Measurement of Adherence to Out-Patient Airway Clearance Therapy by High-Frequency Chest Wall Compression in Cystic Fibrosis.

Respir Care. 2017 Apr 19;:

Authors: Mikesell CL, Kempainen RR, Laguna TA, Menk JS, Wey AR, Gaillard PR, Regelmann WE

Abstract
BACKGROUND: Objective measures of adherence to high-frequency chest wall compression (HFCWC, also known as high frequency chest wall oscillation, HFCWO), a form of airway clearance therapy for patients with cystic fibrosis, are lacking. We used a novel electronic monitoring device integrated into an HFCWC vest to measure adherence compared with self-reported adherence. We determined factors that influenced adherence and how adherence correlated with baseline pulmonary function and pulmonary exacerbations.
METHODS: Data were collected by direct measurement of date, time of day, and duration of HFCWC use to determine the number of daily treatments and daily duration of treatments. Chart review provided prescribed airway clearance therapy treatment and demographic and clinical information. Subject and caregiver report of the daily number of airway clearance therapy treatments was obtained by telephone interviews. Analysis used 2-sample and paired t test, analysis of variance, and linear regression.
RESULTS: Average adherence was 69%. Adherence was highest in children (82%, P = .02) and those receiving assistance with treatment (82%, P < .001). Subjects overestimated therapy duration from a mean ± SD of 127 ± 169% by adults to 19.2 ± 26.3% by parents or guardians of children. Average adherence decreased with increasing prescribed therapy time (P = .02). Average daily therapy time and adherence had significant positive associations with baseline FEV1 percent of predicted (P =.02 and P = .02, respectively) and negative associations with pulmonary exacerbations during the pre-study period and at baseline (P = .044 and P = .02, respectively).
CONCLUSIONS: Greater adherence to HFCWC measured directly by a novel recorder was associated with better baseline pulmonary function and fewer exacerbations in the pre-study and baseline period. Adherence decreased with age and prescribed therapy time and increased with therapy assistance. Self-report overestimation is large and thus not an accurate measure of adherence.

PMID: 28424226 [PubMed - as supplied by publisher]

Systematic review of the safety and efficacy of palivizumab among infants and young children with cystic fibrosis.

Pharmacotherapy. 2017 Apr 19;:

Authors: Kua KP, Lee SWH

Abstract
BACKGROUND: Respiratory syncytial virus (RSV) is a common pathogen in infants with cystic fibrosis (CF). The use of palivizumab prophylaxis for RSV infection as the standard of care for infants with CF remains controversial.
OBJECTIVE: To evaluate the efficacy of palivizumab in reducing the incidence of RSV hospitalization in children with CF who are younger than 2 years of age.
METHODS: Four electronic databases (PubMed, Embase, CINAHL, and CENTRAL) were searched from inception until January 31, 2017 for clinical studies investigating the use of palivizumab in infants with CF aged less than 2 years. The primary outcome was hospitalization rate due to RSV infection. Secondary outcomes included hospitalization for respiratory illness, length of hospital stay, safety (adverse effects), and cost-effectiveness of palivizumab prophylaxis.
RESULTS: The review included a total of ten studies (six cohort studies, two before-and-after studies, one cross-sectional study, and one randomized controlled trial) involving 3,891 patients with CF. Seven studies reported that palivizumab prophylaxis had a positive impact on the rate of RSV hospitalization. Five studies (n=3,404) reported that palivizumab prophylaxis significantly reduced the rate of hospitalization due to RSV infection compared to no prophylaxis. One study (n=5) demonstrated patients with CF who received palivizumab had no RSV hospitalization. Another study showed infants with CF receiving palivizumab (n=117) had a lower risk of hospitalization for RSV infection compared with premature infants (gestational age <35 completed weeks) who received palivizumab (n=4,880).
CONCLUSIONS: Evidence from the literature suggests that palivizumab may have a potential role in reducing RSV hospitalization in children aged less than 2 years with CF. Given the lack of overall data, additional research is warranted to better understand the efficacy and safety of prophylactic palivizumab in infants with CF. This article is protected by copyright. All rights reserved.

PMID: 28423192 [PubMed - as supplied by publisher]

Adult Onset Cystic Fibrosis Liver Disease: Diagnosis and characterization of an underappreciated entity.

Hepatology. 2017 Apr 19;:

Authors: Koh C, Sakiani S, Surana P, Zhao X, Eccleston J, Kleiner DE, Herion D, Liang TJ, Hoofnagle JH, Chernick M, Heller T

Abstract
BACKGROUND & AIMS: Cystic fibrosis liver disease (CFLD), a leading cause of death in cystic fibrosis (CF), is mostly described in pediatric populations. Adult-onset CFLD lacks sufficient characterization and diagnostic tools.
METHODS: A cohort of CF patients without CFLD during childhood were followed for up to 38 years with serologic testing, imaging, and noninvasive fibrosis markers. Historical CFLD diagnostic criteria were compared with a newly proposed CFLD criteria.
RESULTS: 36 CF patients were followed for a median of 24.5 years(IQR=15.6, 32.9). By the last follow-up, 11(31%) had died. With conventional criteria, 8(22%) patients had CFLD, and by new criterion, 17 (47%) had CFLD at a median age of 36.6 years(IQR=26.5, 43.2). By new criterion, those with CFLD had higher median ALT(42 vs 27, p=0.005), AST(26 vs 21, p=0.01), direct bilirubin(0.13 vs 0.1, p=0.01), PT(14.4 vs 12.4, p=0.002), and APRI(0.31 vs 0.23, p=0.003) over the last two years of follow-up. Subjects with a Fibroscan® >6.8kPa had higher ALT(42 vs 28U/L, p=0.02), AST(35 vs 25U/L, p=0.02), APRI(0.77 vs 0.25, p=0.0004), FIB-4(2.14 vs 0.74, p=0.0003) and lower platelet counts(205 vs 293, p=0.02). One CFLD patient had nodular regenerative hyperplasia. Longitudinally, mean platelet counts significantly declined in the CFLD group(310 to 230U/L, p=0.0005). Deceased CFLD patients had lower platelet counts than those alive with CFLD(143 vs 258 U/L, p=0.004) or those deceased with no CFLD(143 vs 327U/L, p=0.006).
CONCLUSION: Adult-onset CFLD may be more prevalent than previously described which suggests a later wave of CFLD that impacts morbidity. Routine liver tests, radiologic imaging, noninvasive fibrosis markers and fibroscan® can be utilized algorithmically to identify adult CFLD. Further evaluation in other CF cohorts should be performed for validation. This article is protected by copyright. All rights reserved.

PMID: 28422310 [PubMed - as supplied by publisher]

Resolvin D1 enhances the resolution of lung inflammation caused by long-term Pseudomonas aeruginosa infection.

Mucosal Immunol. 2017 Apr 19;:

Authors: Codagnone M, Cianci E, Lamolinara A, Mari VC, Nespoli A, Isopi E, Mattoscio D, Arita M, Bragonzi A, Iezzi M, Romano M, Recchiuti A

Abstract
Pseudomonas aeruginosa lung infection is a main cause of disability and mortality worldwide. Acute inflammation and its timely resolution are crucial for ensuring bacterial clearance and limiting tissue damage. Here, we investigated protective actions of resolvin (Rv) D1 in lung infection induced by the RP73 clinical strain of P. aeruginosa. RvD1 significantly diminished bacterial growth and neutrophil infiltration during acute pneumonia caused by RP73. Inoculum of RP73, immobilized in agar beads, resulted in persistent lung infection up to 21 days, leading to a non resolving inflammation reminiscent of human pathology. RvD1 significantly reduced bacterial titer, leukocyte infiltration, and lung tissue damage. In murine lung macrophages sorted during P. aeruginosa chronic infection, RvD1 regulated the expression of Toll-like receptors, downstream genes, and microRNA (miR)-21 and 155, resulting in reduced inflammatory signaling. In vitro, RvD1 enhanced phagocytosis of P. aeruginosa by neutrophils and macrophages, recapitulating its in vivo actions. These results unveil protective functions and mechanisms of action of RvD1 in acute and chronic P. aeruginosa pneumonia, providing evidence for its potent pro-resolution and tissue protective properties on airway mucosal tissue during infection.Mucosal Immunology advance online publication 19 April 2017; doi:10.1038/mi.2017.36.

PMID: 28422188 [PubMed - as supplied by publisher]

Susceptibility of Candida albicans from Cystic Fibrosis Patients.

Mycopathologia. 2017 Apr 18;:

Authors: Sabino R, Carolino E, Moss RB, Banaei N, Verissimo C, Stevens DA

Abstract
Candida albicans is a common microbe, colonizer and potential pathogen found in respiratory cultures of cystic fibrosis (CF) patients. Because of possible development of resistance in patient isolates resulting from residence in the abnormal milieu of CF patient airways, or from exposure to antifungals, and considering the possibility of patient-to-patient spread of microbes and reports of elevated resistance to other fungal pathogens, it was important to assay the susceptibility of isolates of Candida and compare that profile to isolates from the community. In our center, and unlike another fungal pathogen, no increase in resistance of Candida isolates of the CF cohort was found.

PMID: 28421452 [PubMed - as supplied by publisher]

In vivo and In vitro Interactions between Pseudomonas aeruginosa and Staphylococcus spp.

Front Cell Infect Microbiol. 2017;7:106

Authors: Hotterbeekx A, Kumar-Singh S, Goossens H, Malhotra-Kumar S

Abstract
The significance of polymicrobial infections is increasingly being recognized especially in a biofilm context wherein multiple bacterial species-including both potential pathogens and members of the commensal flora-communicate, cooperate, and compete with each other. Two important bacterial pathogens that have developed a complex network of evasion, counter-inhibition, and subjugation in their battle for space and nutrients are Pseudomonas aeruginosa and Staphylococcus aureus. Their strain- and environment-specific interactions, for instance in the cystic fibrosis lung or in wound infections, show severe competition that is generally linked to worse patient outcomes. For instance, the extracellular factors secreted by P. aeruginosa have been shown to subjugate S. aureus to persist as small colony variants (SCVs). On the other hand, data also exist where S. aureus inhibits biofilm formation by P. aeruginosa but also protects the pathogen by inhibiting its phagocytosis. Interestingly, such interspecies interactions differ between the planktonic and biofilm phenotype, with the extracellular matrix components of the latter likely being a key, and largely underexplored, influence. This review attempts to understand the complex relationship between P. aeruginosa and Staphylococcus spp., focusing on S. aureus, that not only is interesting from the bacterial evolution point of view, but also has important consequences for our understanding of the disease pathogenesis for better patient management.

PMID: 28421166 [PubMed - in process]

The Diverse Cellular and Animal Models to Decipher the Physiopathological Traits of Mycobacterium abscessus Infection.

Front Cell Infect Microbiol. 2017;7:100

Authors: Bernut A, Herrmann JL, Ordway D, Kremer L

Abstract
Mycobacterium abscessus represents an important respiratory pathogen among the rapidly-growing non-tuberculous mycobacteria. Infections caused by M. abscessus are increasingly found in cystic fibrosis (CF) patients and are often refractory to antibiotic therapy. The underlying immunopathological mechanisms of pathogenesis remain largely unknown. A major reason for the poor advances in M. abscessus research has been a lack of adequate models to study the acute and chronic stages of the disease leading to delayed progress of evaluation of therapeutic efficacy of potentially active antibiotics. However, the recent development of cellular models led to new insights in the interplay between M. abscessus with host macrophages as well as with amoebae, proposed to represent the environmental host and reservoir for non-tuberculous mycobacteria. The zebrafish embryo has also appeared as a useful alternative to more traditional models as it recapitulates the vertebrate immune system and, due to its optical transparency, allows a spatio-temporal visualization of the infection process in a living animal. More sophisticated immunocompromised mice have also been exploited recently to dissect the immune and inflammatory responses to M. abscessus. Herein, we will discuss the limitations, advantages and potential offered by these various models to study the pathophysiology of M. abscessus infection and to assess the preclinical efficacy of compounds active against this emerging human pathogen.

PMID: 28421165 [PubMed - in process]

The FOXM1 inhibitor RCM-1 suppresses goblet cell metaplasia and prevents IL-13 and STAT6 signaling in allergen-exposed mice.

Sci Signal. 2017 Apr 18;10(475):

Authors: Sun L, Ren X, Wang IC, Pradhan A, Zhang Y, Flood HM, Han B, Whitsett JA, Kalin TV, Kalinichenko VV

Abstract
Goblet cell metaplasia and excessive mucus secretion associated with asthma, cystic fibrosis, and chronic obstructive pulmonary disease contribute to morbidity and mortality worldwide. We performed a high-throughput screen to identify small molecules targeting a transcriptional network critical for the differentiation of goblet cells in response to allergens. We identified RCM-1, a nontoxic small molecule that inhibited goblet cell metaplasia and excessive mucus production in mice after exposure to allergens. RCM-1 blocked the nuclear localization and increased the proteasomal degradation of Forkhead box M1 (FOXM1), a transcription factor critical for the differentiation of goblet cells from airway progenitor cells. RCM-1 reduced airway resistance, increased lung compliance, and decreased proinflammatory cytokine production in mice exposed to the house dust mite and interleukin-13 (IL-13), which triggers goblet cell metaplasia. In cultured airway epithelial cells and in mice, RCM-1 reduced IL-13 and STAT6 (signal transducer and activator of transcription 6) signaling and prevented the expression of the STAT6 target genes Spdef and Foxa3, which are key transcriptional regulators of goblet cell differentiation. These results suggest that RCM-1 is an inhibitor of goblet cell metaplasia and IL-13 signaling, providing a new therapeutic candidate to treat patients with asthma and other chronic airway diseases.

PMID: 28420758 [PubMed - in process]

Modulation of TMEM16A Channel Activity by the Von Willebrand Factor Type A (VWA) domain of the Calcium-Activated Chloride Channel Regulator 1 (CLCA1).

J Biol Chem. 2017 Apr 18;:

Authors: Sala-Rabanal M, Yurtsever Z, Berry KN, Nichols CG, Brett TJ

Abstract
Calcium-activated chloride channels (CaCCs) are key players in transepithelial ion transport and fluid secretion, smooth muscle constriction, neuronal excitability, and cell proliferation. The CaCC regulator 1 (CLCA1) modulates the activity of the CaCC TMEM16A/Anoctamin 1 (ANO1) by directly engaging the channel at the cell surface, but the exact mechanism is unknown. Here, we demonstrate that the von Willebrand factor type A (VWA) domain within the cleaved CLCA1 N-terminal fragment is necessary and sufficient for this interaction. TMEM16A protein levels on the cell surface were increased in HEK293T cells transfected with CLCA1 constructs containing the VWA domain, and TMEM16A-like currents were activated. Similar currents were evoked in cells exposed to secreted VWA domain alone, and these currents were significantly knocked down by TMEM16A siRNA. VWA-dependent TMEM16A modulation was not modified by the S357N mutation, a VWA domain polymorphism associated with more severe meconium ileus in cystic fibrosis (CF) patients. VWA-activated currents were significantly reduced in the absence of extracellular Mg2+, and mutation of residues within the conserved metal ion-dependent adhesion site (MIDAS) motif impaired the ability of VWA to potentiate TMEM16A activity, suggesting that CLCA1-TMEM16A interactions are Mg2+- and MIDAS-dependent. Increase in TMEM16A activity occurred within minutes of exposure to CLCA1 or after a short treatment with nocodazole, consistent with the hypothesis that CLCA1 stabilizes TMEM16A at the cell surface by preventing its internalization. Our study hints at the therapeutic potential of the selective activation of TMEM16A by the CLCA1 VWA domain in loss-of-function chloride channelopathies, such as CF.

PMID: 28420732 [PubMed - as supplied by publisher]

Nutritional management of cystic fibrosis an update for the 21st century.

Paediatr Respir Rev. 2017 Mar 14;:

Authors: Collins S

Abstract
Nutritional management is an essential part of multidisciplinary care for infants, children and adults with cystic fibrosis (CF). In 2016 two updated nutritional consensus guidelines were published [1,2]. This review will explore some of the key points in the nutritional management of people with CF in the 21st Century.

PMID: 28420572 [PubMed - as supplied by publisher]

Dry powders for the inhalation of ciprofloxacin or levofloxacin combined with a mucolytic agent for cystic fibrosis patients.

Drug Dev Ind Pharm. 2017 Apr 19;:1-35

Authors: Akdag Cayli Y, Sahin S, Buttini F, Balducci AG, Montanari S, Vural I, Oner L

Abstract
OBJECTIVE: This study aimed to design and characterize an inhalable dry powder of ciprofloxacin or levofloxacin combined with the mucolytics acetylcysteine and dornase alfa for the management of pulmonary infections in patients with cystic fibrosis.
METHODS: Ball milling, homogenization in isopropyl alcohol, and spray drying processes were used to prepare dry powders for inhalation. Physico-chemical characteristics of the dry powders were assessed via thermogravimetric analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry, and scanning electron microscopy. The particle size distribution, dissolution rate, and permeability across Calu-3 cell monolayers were analyzed. The aerodynamic parameters of dry powders were determined using the Andersen cascade impactor (ACI).
RESULTS: After the micronization process, the particle sizes of the raw materials significantly decreased. X-ray and DSC results indicated that although ciprofloxacin showed no changes in its crystal structure, the structure of levofloxacin became amorphous after the micronization process. FT-IR spectra exhibited the characteristic peaks for ciprofloxacin and levofloxacin in all formulations. The dissolution rates of micro-homogenized and spray-dried ciprofloxacin were higher than that of untreated ciprofloxacin. ACI results showed that all formulations had a mass median aerodynamic diameter less than 5 µm; however, levofloxacin microparticles showed higher respirability than ciprofloxacin powders did. The permeability of levofloxacin was higher than those of the ciprofloxacin formulations.
CONCLUSION: Together, our study showed that these methods could suitably characterize antibiotic and mucolytic-containing dry powder inhalers.

PMID: 28420285 [PubMed - as supplied by publisher]

Infections With Biofilm Formation: Selection of Antimicrobials and Role of Prolonged Antibiotic Therapy.

Pediatr Infect Dis J. 2016 06;35(6):695-7

Authors: Beaudoin T, Waters V

PMID: 26986772 [PubMed - indexed for MEDLINE]

O-Aminobenzoyl-S-Nitrosoglutathione: a Fluorogenic, Cell Permeable, Pseudo-Substrate for S-Nitrosoglutathione Reductase.

Free Radic Biol Med. 2017 Apr 15;:

Authors: Sun BL, Palmer L, Alam SR, Adekoya I, Brown-Steinke K, Periasamy A, Mutus B

Abstract
S-nitrosoglutathione reductase (GSNOR) is a multifunctional enzyme. It can catalyze NADH-dependent reduction of S-nitrosoglutathione (GSNO); as well as NAD(+)-dependent oxidation of hydroxymethylglutathione (HMGSH; an adduct formed by the spontaneous reaction between formaldehyde and glutathione). While initially recognized as the enzyme that is involved in formaldehyde detoxification, increasing amount of research evidence has shown that GSNOR also plays a significant role in nitric oxide mediated signaling through its modulation of protein S-nitrosothiol abundance via transnitrosation reactions with GSNO. In humans, GSNOR/S-nitrosothiols have been implicated in the etiology of several diseases including lung cancer, cystic fibrosis, asthma, pulmonary hypertension, and neuronal dysfunction. Currently, it is not possible to monitor the activity of GSNOR in live cells. In this article, we present a new compound, O-aminobenzoyl-S-nitrosoglutathione (OAbz-GSNO), which acts as a fluorogenic pseudo-substrate for GSNOR with an estimated Km value of 320µM. The weak OAbz-GSNO fluorescence increases by approximately 14 fold upon reduction of its S-NO moiety. In live cell imaging studies, OAbz-GSNO is readily taken up by primary pulmonary endothelial cells and localizes to the same perinuclear region as GSNOR. The perinuclear OAbz-GSNO fluorescence increases in a time dependent manner and this increase in fluorescence is abolished by siRNA knockdown of GSNOR or by treatment with GSNOR-specific inhibitors N6022 and C3. Taken together, these data demonstrate that OAbz-GSNO can be used as a tool to monitor the activity of GSNOR in live cells.

PMID: 28419866 [PubMed - as supplied by publisher]

The magnitude of ivacaftor effects on fluid secretion via R117H-CFTR channels: Human in vivo measurements.

PLoS One. 2017;12(4):e0175486

Authors: Char JE, Dunn C, Davies Z, Milla C, Moss RB, Wine JJ

Abstract
We optically measured effects of orally available ivacaftor (Kalydeco®) on sweat rates of identified glands in 3 R117H subjects, each having a unique set of additional mutations, and compared them with 5 healthy control subjects tested contemporaneously. We injected β-adrenergic agonists intradermally to stimulate CFTR-dependent 'C-sweat' and methacholine to stimulate 'M-sweat', which persists in CF subjects. We focused on an R117H-7T/F508del subject who produced quantifiable C-sweat off ivacaftor and was available for 1 blinded, 3 off ivacaftor, and 3 on ivacaftor tests, allowing us to estimate in vivo fold-increase in sweat rates produced by ivacaftor's effect on the open probability (PO) of R117H-CFTR. Measured sweat rates must be corrected for sweat losses. With estimated sweat losses of 0.023 to 0.08 nl·gland-1·min-1, ivacaftor increased the average C-sweat rates 3-7 fold, and estimated function as % of WT were 4.1-12% off ivacaftor and 21.9-32% on ivacaftor (larger values reflect increased loss estimates). Based on single tests, an R117H-7T/ R117H-7T subject showed 6-9% WT function off ivacaftor and 28-43% on ivacaftor. Repeat testing of an R117H-5T/F508del subject detected only trace responding to ivacaftor. We conclude that in vivo, R117H PO is strongly increased by ivacaftor, but channel number, mainly determined by variable deletion of exon 10, has a marked influence on outcomes.

PMID: 28419121 [PubMed - in process]

Inhaled Heparin: Therapeutic Efficacy and Recent Formulations.

J Aerosol Med Pulm Drug Deliv. 2017 Apr 18;:

Authors: Yildiz-Pekoz A, Ozsoy Y

Abstract
Heparin is well known for its anticoagulant and anti-inflammatory properties. Inhaled heparin regimens are increasingly being used to manage lung disease. It has been used to treat cystic fibrosis, thromboembolism, and pulmonary fibrosis, as well as bronchial asthma and asthma-induced airway hypersensitivity. Several preclinical studies attained some useful effects of heparin-administered, parenterally and through inhalation, treatment of lung disease. Besides, recent clinical trials suggest that inhaled heparin for lung diseases is beneficial and safe, but such data remain to be limited. In 2005, the orphan designation was granted by the European Commission for heparin sodium (inhalation use) for the treatment of cystic fibrosis. The positive results of heparin in the pulmonary route necessitate a focus on the preparation and evaluation of heparin in advanced drug delivery systems, namely nano/microparticles and liposomes. Through this pulmonary delivery, heparin is protected from enzymatic degradation within the airway. Heparin is thus passively targeted into the lungs, and long-lasting localized treatment is achieved. On the other hand, these systems have encountered several problems as follows: (1) polymers, such as poly-L-lactide-glycolic acid, poly (lactic acid), and chitosan, used to prepare heparin-loaded microparticle/nanoparticle (MP/NP) systems have not been granted approval for lung application by the FDA and (2) liposomal and NP formulation stability is the main problem of formulation design. We propose that additional in vitro and in vivo research is necessary to assess the clinical applicability of this treatment strategy. The present article discusses heparin treatments for lung diseases and the use of heparin and/or heparin-loaded drugs in advanced delivery systems through the pulmonary route.

PMID: 28418758 [PubMed - as supplied by publisher]

Physical characterization of Tobramycin Inhalation Powder: II. State Diagram of an Amorphous Engineered Particle Formulation.

Mol Pharm. 2017 Apr 18;:

Authors: Miller D, Tan T, Nakamura J, Malcolmson R, Tarara T, Weers J

Abstract
Tobramycin Inhalation Powder (TIP) is a spray-dried engineered particle formulation used in TOBI® Podhaler®, a drug/device combination for treatment of cystic fibrosis. A TIP particle consists of two phases: amorphous, glassy tobramycin sulfate and a gel-phase phospholipid (DSPC). The objective of this work was to characterize both the amorphous and gel phases following exposure of TIP to a broad range of relative humidity and temperature. Because, in principle, changes in either particle morphology or the solid-state form of the drug could affect drug delivery or biopharmaceutical properties, understanding physical stability was critical to development and registration of this product. Studies included morphological assessments of particles, thermal analysis to measure the gel-to-liquid crystalline phase transition (Tm) of the phospholipid and the glass transition temperature (Tg) of tobramycin sulfate, enthalpy relaxation measurements to estimate structural relaxation times, and gravimetric vapor sorption to measure moisture sorption isotherms of TIP and its components. Collectively, these data enabled development of a state diagram for TIP - a map of the environmental conditions under which physical stability can be expected. This diagram shows that, at long-term storage conditions, TIP is at least 50°C below the Tg of the amorphous phase and at least 40°C below the Tm of the gel phase. Enthalpy relaxation measurements demonstrate that the characteristic structural relaxation times under these storage conditions are many orders of magnitude greater than that at Tg. These data, along with long-term physicochemical stability studies conducted during product development, demonstrate that TIP is physically stable, remaining as a mechanical solid over timescales and conditions relevant to a pharmaceutical product. This met a key design goal in the development of TIP: a room-temperature-stable formulation (three years of shelf-life) that obviates the need for refrigeration for long-term storage. This has enabled development of TOBI Podhaler - an approved inhaled drug product that meaningfully reduces the treatment burden of cystic fibrosis patients worldwide.

PMID: 28418683 [PubMed - as supplied by publisher]

Prophylactic anti-staphylococcal antibiotics for cystic fibrosis.

Cochrane Database Syst Rev. 2017 Apr 18;4:CD001912

Authors: Smyth AR, Rosenfeld M

Abstract
BACKGROUND: Staphylococcus aureus causes pulmonary infection in young children with cystic fibrosis. Prophylactic antibiotics are prescribed hoping to prevent such infection and lung damage. Antibiotics have adverse effects and long-term use might lead to infection with Pseudomonas aeruginosa. This is an update of a previously published review.
OBJECTIVES: To assess continuous oral antibiotic prophylaxis to prevent the acquisition of Staphylococcus aureus versus no prophylaxis in people with cystic fibrosis, we tested these hypotheses. Prophylaxis:1. improves clinical status, lung function and survival;2. causes adverse effects (e.g. diarrhoea, skin rash, candidiasis);3. leads to fewer isolates of common pathogens from respiratory secretions;4. leads to the emergence of antibiotic resistance and colonisation of the respiratory tract with Pseudomonas aeruginosa.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Companies manufacturing anti-staphylococcal antibiotics were contacted.Most recent search of the Group's Register: 29 September 2016.
SELECTION CRITERIA: Randomised trials of continuous oral prophylactic antibiotics (given for at least one year) compared to intermittent antibiotics given 'as required', in people with cystic fibrosis of any disease severity.
DATA COLLECTION AND ANALYSIS: The authors assessed studies for eligibility and methodological quality and extracted data.
MAIN RESULTS: We included four studies, with a total of 401 randomised participants aged zero to seven years on enrolment; one study is ongoing. The two older included studies generally had a higher risk of bias across all domains, but in particular due to a lack of blinding and incomplete outcome data, than the two more recent studies. We only regarded the most recent study as being generally free of bias, although even here we were not certain of the effect of the per protocol analysis on the study results. Evidence was downgraded based on GRADE assessments and outcome results ranged from moderate to low quality. Downgrading decisions were due to limitations in study design (all outcomes); for imprecision (number of people needing additional antibiotics); and for inconsistency (weight z score).Fewer children receiving anti-staphylococcal antibiotic prophylaxis had one or more isolates of Staphylococcus aureus (low quality evidence). There was no significant difference between groups in infant or conventional lung function (moderate quality evidence). We found no significant effect on nutrition (low quality evidence), hospital admissions, additional courses of antibiotics (low quality evidence) or adverse effects (moderate quality evidence). There was no significant difference in the number of isolates of Pseudomonas aeruginosa between groups (low quality evidence), though there was a trend towards a lower cumulative isolation rate of Pseudomonas aeruginosa in the prophylaxis group at two and three years and towards a higher rate from four to six years. As the studies reviewed lasted six years or less, conclusions cannot be drawn about the long-term effects of prophylaxis.
AUTHORS' CONCLUSIONS: Anti-staphylococcal antibiotic prophylaxis leads to fewer children having isolates of Staphylococcus aureus, when commenced early in infancy and continued up to six years of age. The clinical importance of this finding is uncertain. Further research may establish whether the trend towards more children with CF with Pseudomonas aeruginosa, after four to six years of prophylaxis, is a chance finding and whether choice of antibiotic or duration of treatment might influence this.

PMID: 28417451 [PubMed - as supplied by publisher]