P.TYR1381X: Are We Facing a New Mutation of CFTR in a Patient With Severe Cystic Fibrosis?

Arch Bronconeumol. 2019 Aug 10;:

Authors: Pereiro-Brea T, Palacios-Bartolomé A, Lourido-Cebreiro T, Casal-Mouriño A, Barros-Angueira F, Pérez Del Molino ML, Valdés L

PMID: 31409507 [PubMed - as supplied by publisher]

A paper-based length of stain analytical device for naked eye (readout-free) detection of cystic fibrosis.

Anal Chim Acta. 2019 Nov 08;1080:138-145

Authors: Taghizadeh-Behbahani M, Hemmateenejad B, Shamsipur M, Tavassoli A

Abstract
The test of sweat chloride is routinely performed as a worldwide newborn screening (NBS) to the diagnosis of cystic fibrosis (CF) in infants. However, the available methods for measurement of chloride in sweat suffer from such limitations as either low selectivity and/or requiring relatively large sample size. In this work, we have designed an analytical ruler that can measure chloride ion in sweat and hence can be used for the diagnosis of cystic fibrosis. This micro-pad (μ-PAD) device is fabricated by making hydrophilic micro-channel on a filter paper impregnated with silver dichromate. After addition of chloride ion-containing sweat sample, it moves through the channel, leading to the formation of an AgCl sediment, which deposits as a white color stain, the length of which in the channel being proportional to the amount of chloride ion in sweat. A well-defined linear relation was observed between the length of white color stain and the concentration of chloride ion in the sample solutions with a relative standard deviation of 3.6% (n = 3) for an artificial sweat sample containing 100 mM chloride ion. The possible interfering effects of several different cations and anions on the detection of chloride ion were investigated and the results well-confirmed the selectivity of the proposed method. With the use of only 2.0 μL of the sample solution, the μPAD was able to measure the chloride content of sweat over a concentration range of 20.0-100.0 mM, which covers both the healthy range (˂ 40 mM) and the risky range (˃60 mM) of chloride ion. Analysis of chloride content of sweat samples by the μPAD agreed well with those obtained by a standard electrochemical method (with relative errors of lower than 10%).

PMID: 31409463 [PubMed - in process]

Health-resource use and quality of life in children with bronchiectasis: a multi-center pilot cohort study.

BMC Health Serv Res. 2019 Aug 13;19(1):561

Authors: Lovie-Toon YG, Grimwood K, Byrnes CA, Goyal V, Busch G, Masters IB, Marchant JM, Buntain H, O'Grady KF, Chang AB

Abstract
BACKGROUND: Bronchiectasis in children is an important, but under-researched, chronic pulmonary disorder that has negative impacts on health-related quality of life. Despite this, it does not receive the same attention as other chronic pulmonary conditions in children such as cystic fibrosis. We measured health resource use and health-related quality of life over a 12-month period in children with bronchiectasis.
METHODS: We undertook a prospective cohort study of 85 children aged < 18-years with high-resolution chest computed-tomography confirmed bronchiectasis undergoing management in three pediatric respiratory medical clinics in Darwin and Brisbane, Australia and Auckland, New Zealand. Children with cystic fibrosis or receiving cancer treatment were excluded. Data collected included the frequency of healthcare attendances (general practice, specialists, hospital and/or emergency departments, and other), medication use, work and school/childcare absences for parents/carers and children respectively, and both parent/carer and child reported quality of life and cough severity.
RESULTS: Overall, 951 child-months of observation were completed for 85 children (median age 8.7-years, interquartile range 5.4-11.3). The mean (standard deviation) number of exacerbations was 3.3 (2.2) per child-year. Thirty of 264 (11.4%) exacerbation episodes required hospitalization. Healthcare attendance and antibiotic use rates were high (30 and 50 per 100 child-months of observation respectively). A carer took leave from work for 53/236 (22.5%) routine clinic visits. Absences from school/childcare due to bronchiectasis were 24.9 children per 100 child-months. Quality of life scores for both the parent/carer and child were highly-correlated with one another, remained stable over time and were negatively associated with cough severity.
CONCLUSIONS: Health resource use in this cohort of children is high, reflecting their severe disease burden. Studies are now needed to quantify the direct and societal costs of disease and to evaluate interventions that may reduce disease burden, particularly hospitalizations.

PMID: 31409413 [PubMed - in process]

Patient-reported outcomes in patients with cystic fibrosis with a G551D mutation on ivacaftor treatment: results from a cross-sectional study.

BMC Pulm Med. 2019 Aug 13;19(1):146

Authors: Bell SC, Mainz JG, MacGregor G, Madge S, Macey J, Fridman M, Suthoff ED, Narayanan S, Kinnman N

Abstract
BACKGROUND: Clinical studies demonstrate that ivacaftor (IVA) improves health-related quality of life (HRQoL) in patients aged ≥6 years with cystic fibrosis (CF). The real-world impact of IVA and standard of care (SOC) in groups of patients with G551D and F508del mutations, respectively, was assessed using a survey comprising disease-specific and generic HRQoL measures.
METHODS: Patients with CF aged ≥12 years, or aged 6-11 years with caregiver support, with either (1) a G551D mutation and receiving IVA (G551D/IVA) for ≥3 months, or (2) homozygous for F508del and receiving SOC before lumacaftor/IVA availability (F508del/SOC), were eligible to participate in a cross-sectional survey. Demographic and clinical characteristics, and HRQoL measures were compared between patient groups, and multiple regression analyses were conducted.
RESULTS: After differences in patient demographic and clinical characteristics were controlled for, significantly better scores were observed in the G551D/IVA group than in the F508del/SOC group on multiple domains of the validated Cystic Fibrosis Questionnaire-Revised and the EuroQol 5-dimensions 5-level questionnaire.
CONCLUSIONS: G551D/IVA patients reported better HRQoL than F508del/SOC patients on generic and disease-specific measures in a real-world setting.

PMID: 31409396 [PubMed - in process]

A Latent Class Approach to Modeling Trajectories of Health Care Cost in Pediatric Cystic Fibrosis.

Med Decis Making. 2019 Aug 13;:272989X19859875

Authors: Levy JF, Rosenberg MA

Abstract
Introduction. Estimating costs of medical care attributable to treatments over time is difficult due to costs that cannot be explained solely by observed risk factors. Unobserved risk factors cannot be accounted for using standard econometric techniques, potentially leading to imprecise prediction. The goal of this work is to describe methodology to account for latent variables in the prediction of longitudinal costs. Methods. Latent class growth mixture models (LCGMMs) predict class membership using observed risk factors and class-specific distributions of costs over time. Our motivating example models cost of care for children with cystic fibrosis from birth to age 17. We compare a generalized linear mixed model (GLMM) with LCGMMs. Both models use the same covariates and distribution to predict average costs by combinations of observed risk factors. We adopt a Bayesian estimation approach to both models and compare results using the deviance information criterion (DIC). Results. The 3-class LCGMM model has a lower DIC than the GLMM. The LCGMM latent classes include a low-cost group where costs increase slowly over time, a medium-cost group with initial higher costs than the low-cost group and with more rapidly increasing costs at older ages, and a high-cost group with a U-shaped trajectory. The risk profile-specific mixtures of classes are used to predict costs over time. The LCGMM model shows more delineation of costs by age by risk profile and with less uncertainty than the GLMM model. Conclusions. The LCGMM approach creates flexible prediction models when using longitudinal cost data. The Bayesian estimation approach to LCGMM presented fits well into cost-effectiveness modeling where the estimated trajectories and class membership can be used for prediction.

PMID: 31409187 [PubMed - as supplied by publisher]

Inhaled Corticosteroids for Cystic Fibrosis: A Review of Clinical Effectiveness

Book. 2019 03 12

Authors: Peprah K, McCormack S

Abstract
Cystic fibrosis (CF) is a rare chronic genetic disease that affects multiple systems in the body including the respiratory tract, pancreas, gastro-intestinal tract and liver.1,2 The disorder is caused by mutations of the CF transmembrane conductance regulator (CFTR) gene. Approximately, one in 25 Canadians carries an abnormal CFTR gene, and CF occurs in children who inherit two abnormal genes, one from each parent.3 It is estimated that one in every 3,600 children born in Canada has CF, with more than 4,300 Canadian children, adolescents, and adults with CF attending specialized CF clinics.3 The disease has no cure at present, and it is the most common fatal genetic disease affecting Canadian children and young adults3 Lung disease is the most prominent manifestation of CF, and it is reported to account for nearly 85% of deaths.4 Respiratory tract abnormalities in CF patients cause mucus plugging of the airways, bronchial wall thickening due to inflammation, increased susceptibility to respiratory tract infection, and airway destruction.1,2 Much of the pulmonary damage begins with lung inflammation.5 Although a normal inflammatory response is beneficial to host defence mechanisms, and helps to prevent the spread of infection, the excessive inflammation seen in CF patients is harmful as it contributes to the disease and associated death.1 One of the goals in the treatment of cystic fibrosis is to reduce lung inflammation.4 Corticosteroids are potent anti-inflammatory drugs which have been widely used in the treatment of a variety of diseases with underlying inflammation including asthma and chronic obstructive pulmonary disease (COPD).1,4 They exert direct inhibitory effects on many inflammatory cells, and regular use of inhaled corticosteroids (ICS) has been reported to reduce the number of mast cells within the airways, decrease airway microvascular leakage, and lessen mucus production.4 Although benefit of its use in CF has not been proven, ICS has been widely prescribed as anti-inflammatory agents to treat children and adults with CF empirically.1,4,5 The objective of this report is to summarize the evidence regarding the clinical effectiveness of ICS for the treatment of CF.

PMID: 31411842

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The role of endothelial cells in cystic fibrosis.

J Cyst Fibros. 2019 Aug 07;:

Authors: Declercq M, Treps L, Carmeliet P, Witters P

Abstract
Cystic fibrosis (CF) is an autosomal recessive disease caused by the loss of function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein which primarily acts as a chloride channel. CFTR has mainly been studied in epithelial cells although it is also functional and expressed in other cell types including endothelial cells. The present review summarizes current knowledge on the role of the endothelium in CF. More specifically, this review highlights the role of endothelial cells in CF in acting as a semipermeable barrier, as a key regulator of angiogenesis, coagulation, the vascular tone and the inflammatory responses. It could contribute to different aspects of the disease including cardiovascular symptoms, excessive blood vessel formation, pulmonary and portal hypertension and CF-related diabetes. Despite the important role of vascular endothelium in many biological processes, it has largely been under investigated in CF.

PMID: 31401006 [PubMed - as supplied by publisher]

Benzyloxycarbonyl-proline-prolinal (ZPP): Dual complementary roles for neutrophil inhibition.

Biochem Biophys Res Commun. 2019 Aug 07;:

Authors: Russell DW, Hardison M, Genschmer KR, Szul T, Bratcher PE, Abdul Roda M, Xu X, Viera L, Blalock JE, Gaggar A, Noerager BD

Abstract
Neutrophil influx and activation contributes to organ damage in several major lung diseases. This inflammatory influx is initiated and propagated by both classical chemokines such as interleukin-8 and by downstream mediators such as the collagen fragment cum neutrophil chemokine Pro-Gly-Pro (PGP), which share use of the ELR + CXC receptor family. Benzyloxycarbonyl-proline-prolinal (ZPP) is known to suppress the PGP pathway via inhibition of prolyl endopeptidase (PE), the terminal enzyme in the generation of PGP from collagen. However, the structural homology of ZPP and PGP suggests that ZPP might also directly affect classical glutamate-leucine-arginine positive (ELR+) CXC chemokine signaling. In this investigation, we confirm that ZPP inhibits PE in vitro, demonstrate that ZPP inhibits both ELR + CXC and PGP-mediated chemotaxis in human and murine neutrophils, abrogates neutrophil influx induced by murine intratracheal challenge with LPS, and attenuates human neutrophil chemotaxis to sputum samples of human subjects with cystic fibrosis. Cumulatively, these data demonstrate that ZPP has dual, complementary inhibitory effects upon neutrophil chemokine/matrikine signaling which make it an attractive compound for clinical study of neutrophil inhibition in conditions (such as cystic fibrosis and chronic obstructive pulmonary disease) which evidence concurrent harmful increases of both chemokine and matrikine signaling.

PMID: 31400851 [PubMed - as supplied by publisher]

Distribution and outcomes of infection of Mycobacterium avium complex species in cystic fibrosis.

J Cyst Fibros. 2019 Aug 06;:

Authors: Azar M, Zimbric M, Shedden K, Caverly LJ

Abstract
BACKGROUND: The majority of nontuberculous mycobacterial (NTM) pulmonary infections in people with cystic fibrosis (CF) are caused by Mycobacterium avium complex (MAC) species. Data on MAC species distribution and outcomes of infection in CF are lacking.
METHODS: This was a single center, retrospective study. MAC isolates had species identification with MLSA of rpoB and the 16S23S ITS region. Clinical data were compared between species.
RESULTS: Twenty-three people with CF and 57 MAC isolates were included. Infection with M. avium was the most common (65.2%). M. intracellulare was associated with higher rates of NTM disease, younger age, and steeper decline in lung function prior to infection.
CONCLUSIONS: We observed worse clinical outcomes in people with M. intracellulare infection relative to other MAC species. Further investigation of clinical outcomes of MAC infection among CF patients is warranted to better define the utility of species-level identification of MAC isolates in CF.

PMID: 31399327 [PubMed - as supplied by publisher]

[Prenatal diagnosis and postnatal outcome of isolated intra-abdominal calcifications: a 10-year experience from a referral fetal medicine center].

Gynecol Obstet Fertil Senol. 2019 Aug 06;:

Authors: Maisonneuve E, Debain L, Garel C, Hervieux E, Lafon B, Dhombres F, Kayem G, Jouannic JM

Abstract
INTRODUCTION: Intra-abdominal calcifications (iAC) detected during fetal ultrasound examinations are characterized by their isolated or associated nature, as well as their location. Our objective was to describe all cases of isolated iAC along with their etiological investigations and neonatal outcome, during a 10-year practice in a referral center.
METHODS: We conducted a retrospective descriptive monocentric study on neonates diagnosed with isolated iAC after antenatal expert ultrasound scan and referred to the Multidisciplinary Center for Prenatal Diagnosis at Trousseau Hospital and born between January 1st, 2008 and June 30th, 2018. The exclusion criteria were: retroperitoneal calcifications, iAC associated with other digestive abnormalities or with congenital malformations.
RESULTS: The 32 isolated iAC cases accounted for 46% of all iAC. Nine cases were excluded for missing neonatal data. Among the 23 remaining isolated iAC cases, we observed 15 intra-hepatic calcifications, 5 peri-hepatic and two peritoneal calcifications. One fetus had both intra- and peri-hepatic calcifications. The majority of iAC remained stable throughout pregnancy. No cases of aneuploidy, fetal infection, or cystic fibrosis were detected. The neonatal outcome was favorable in all cases.
CONCLUSIONS: In case of isolated and stable iAC after expert ultrasound scan, after having ruled out infectious diseases of the fetus and looked for the most frequent mutations of cystic fibrosis in the parents, the prognosis is favorable. Fetal karyotyping is recommended when additional structural anomalies are present.

PMID: 31398445 [PubMed - as supplied by publisher]

Inhalable combination powder formulations of phage and ciprofloxacin for P. aeruginosa respiratory infections.

Eur J Pharm Biopharm. 2019 Aug 06;:

Authors: Lin Y, Chang RYK, Britton WJ, Morales S, Kutter E, Li J, Chan HK

Abstract
Recently we showed that nebulized ciprofloxacin and phage PEV20 in combination had a synergistic bactericidal effect against antibiotic-resistant Pseudomonas aeruginosa isolates from patients with cystic fibrosis. Compared to nebulization, dry powders for inhalation may improve patient handling characteristics and compliance. In the present study, we co-spray dried ciprofloxacin and phage PEV20 using L-leucine with or without lactose as excipients. Two formulations were identified for testing in this study. The mass ratios were set at 1:1:1 for ciprofloxacin, lactose and L-leucine (Formulation A) or 2:1 for ciprofloxacin and L-leucine without lactose (Formulation B). Concentrations of PEV20 were set at 108 and 109 PFU/mL for two clinical P. aeruginosa strains FADD1-PA001 and JIP865, respectively. Formulations A and B were characterized as partially crystalline and the powders recrystallized at >40% relative humidity (RH). Both formulations exhibited strong synergistic antimicrobial killing effect on the two strains. Formulations A and B maintained bactericidal synergy after dispersion using both low and high resistance OsmohalerTM. Powder aerosol performance was examined by next generation impactor (NGI) in low resistance inhaler at 100 L/min and by multi-stage liquid impinger (MSLI) in high resistance inhaler at 60 L/min.Fine particle fractions (FPF) obtained by NGI were 64.3 ± 2.9% and 59.7 ± 2.1% for A and B, respectively. FPF obtained by MSLI were 71.0 ± 3.4% and 73.3 ± 5.0%, respectively. In conclusion, it is feasible to prepare stable and inhalable combination powder formulations of phage PEV20 and ciprofloxacin for potential treatment of respiratory infections caused by multi-drug resistant (MDR) P. aeruginosa.

PMID: 31398437 [PubMed - as supplied by publisher]

Prevention of chronic infection with Pseudomonas aeruginosa infection in cystic fibrosis.

Curr Opin Pulm Med. 2019 Aug 07;:

Authors: Zemanick ET, Bell SC

Abstract
PURPOSE OF REVIEW: This review provides an update on definitions of chronicity of infection, approaches to airway sampling to detect infection, strategies for Pseudomonas aeruginosa eradication, impact of cystic fibrosis transmembrane regualtor protein (CFTR) modulators and future challenges for clinical trials.
RECENT FINDINGS: Rates of P. aeruginosa have decreased over the past two decades with establishment of effective eradication protocols. Definitions of chronic P. aeruginosa infection have required adaptation for healthier populations. Although molecular (PCR) approaches to early P. aeruginosa detection are sensitive, to date, earlier diagnosis has not impacted on clinical outcomes. Despite eradication regimens, some people with early P. aeruginosa fail to clear their infection. Most people also experience a recurrence and eventual transition to chronic infection. Several recent studies sought to address this gap. CFTR modulators (predominantly ivacaftor) demonstrated reduced P. aeruginosa density, although infection may persist or recur demonstrating the need for continued antiinfective therapies in the modulator era.
SUMMARY: Future studies of approaches to P. aeruginosa eradication will be complex due to expanded availability and ongoing competitive clinical trials of CFTR modulators. Studies to address optimal eradication therapy, particularly in adults, will be required, though adequate recruitment to power these studies may prove challenging.

PMID: 31397692 [PubMed - as supplied by publisher]

On the self-triggering Cox model for recurrent event data.

Stat Med. 2019 Aug 08;:

Authors: Kim JI, Lin FC, Fine JP

Abstract
Recurrent event data frequently occur in longitudinal studies when subjects experience more than one event during the observation period. Often, the occurrence of subsequent events is associated with the experience of previous events. Such dependence is commonly ignored in the application of standard recurrent event methodology. In this paper, we utilize a Cox-type regression model with time-varying triggering effect depending on the number and timing of previous events to enhance both model fit and prediction. Parameter estimation and statistical inference is achieved via the partial likelihood. A statistical test procedure is provided to assess the existence of the triggering effects. We demonstrate our approach via comprehensive simulation studies and a real data analysis on chronic pseudomonas infections in young cystic fibrosis patients. Our model provides significantly better predictions than standard recurrent event models.

PMID: 31396988 [PubMed - as supplied by publisher]

Inspiration for the Future: The Role of Inspiratory Muscle Training in Cystic Fibrosis.

Sports Med Open. 2019 Aug 08;5(1):36

Authors: Shei RJ, Dekerlegand RL, Mackintosh KA, Lowman JD, McNarry MA

Abstract
Cystic fibrosis (CF) is an inherited, multi-system, life-limiting disease characterized by a progressive decline in lung function, which accounts for the majority of CF-related morbidity and mortality. Inspiratory muscle training (IMT) has been proposed as a rehabilitative strategy to treat respiratory impairments associated with CF. However, despite evidence of therapeutic benefits in healthy and other clinical populations, the routine application of IMT in CF can neither be supported nor refuted due to the paucity of methodologically rigorous research. Specifically, the interpretation of available studies regarding the efficacy of IMT in CF is hampered by methodological threats to internal and external validity. As such, it is important to highlight the inherent risk of bias that differences in patient characteristics, IMT protocols, and outcome measurements present when synthesizing this literature prior to making final clinical judgments. Future studies are required to identify the characteristics of individuals who may respond to IMT and determine whether the controlled application of IMT can elicit meaningful improvements in physiological and patient-centered clinical outcomes. Given the equivocal evidence regarding its efficacy, IMT should be utilized on a case-by-case basis with sound clinical reasoning, rather than simply dismissed, until a rigorous evidence-based consensus has been reached.

PMID: 31396726 [PubMed]

Immunopathology of Airway Surface Liquid Dehydration Disease.

J Immunol Res. 2019;2019:2180409

Authors: Lewis BW, Patial S, Saini Y

Abstract
The primary purpose of pulmonary ventilation is to supply oxygen (O2) for sustained aerobic respiration in multicellular organisms. However, a plethora of abiotic insults and airborne pathogens present in the environment are occasionally introduced into the airspaces during inhalation, which could be detrimental to the structural integrity and functioning of the respiratory system. Multiple layers of host defense act in concert to eliminate unwanted constituents from the airspaces. In particular, the mucociliary escalator provides an effective mechanism for the continuous removal of inhaled insults including pathogens. Defects in the functioning of the mucociliary escalator compromise the mucociliary clearance (MCC) of inhaled pathogens, which favors microbial lung infection. Defective MCC is often associated with airway mucoobstruction, increased occurrence of respiratory infections, and progressive decrease in lung function in mucoobstructive lung diseases including cystic fibrosis (CF). In this disease, a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene results in dehydration of the airway surface liquid (ASL) layer. Several mice models of Cftr mutation have been developed; however, none of these models recapitulate human CF-like mucoobstructive lung disease. As an alternative, the Scnn1b transgenic (Scnn1b-Tg+) mouse model overexpressing a transgene encoding sodium channel nonvoltage-gated 1, beta subunit (Scnn1b) in airway club cells is available. The Scnn1b-Tg+ mouse model exhibits airway surface liquid (ASL) dehydration, impaired MCC, increased mucus production, and early spontaneous pulmonary bacterial infections. High morbidity and mortality among mucoobstructive disease patients, high economic and health burden, and lack of scientific understanding of the progression of mucoobstruction warrants in-depth investigation of the cause of mucoobstruction in mucoobstructive disease models. In this review, we will summarize published literature on the Scnn1b-Tg+ mouse and analyze various unanswered questions on the initiation and progression of mucobstruction and bacterial infections.

PMID: 31396541 [PubMed - in process]

A putative enoyl-CoA hydratase contributes to biofilm formation and the antibiotic tolerance of Achromobacter xylosoxidans.

NPJ Biofilms Microbiomes. 2019;5:20

Authors: Cameron LC, Bonis B, Phan CQ, Kent LA, Lee AK, Hunter RC

Abstract
Achromobacter xylosoxidans has attracted increasing attention as an emerging pathogen in patients with cystic fibrosis. Intrinsic resistance to several classes of antimicrobials and the ability to form robust biofilms in vivo contribute to the clinical manifestations of persistent A. xylosoxidans infection. Still, much of A. xylosoxidans biofilm formation remains uncharacterized due to the scarcity of existing genetic tools. Here we demonstrate a promising genetic system for use in A. xylosoxidans; generating a transposon mutant library which was then used to identify genes involved in biofilm development in vitro. We further described the effects of one of the genes found in the mutagenesis screen, encoding a putative enoyl-CoA hydratase, on biofilm structure and tolerance to antimicrobials. Through additional analysis, we find that a fatty acid signaling compound is essential to A. xylosoxidans biofilm ultrastructure and maintenance. This work describes methods for the genetic manipulation of A. xylosoxidans and demonstrated their use to improve our understanding of A. xylosoxidans pathophysiology.

PMID: 31396394 [PubMed - in process]

A Novel in situ Approach to Studying Pancreatic Ducts in Mice.

Front Physiol. 2019;10:938

Authors: Gál E, Dolenšek J, Stožer A, Pohorec V, Ébert A, Venglovecz V

Abstract
Introduction: The tissue slice technique offers several benefits compared to isolated cells and cell clusters that help us understand the (patho)physiology of several organs in situ. The most prominent features are preserved architecture and function, with intact homotypic and heterotypic interactions between cells in slices. In the pancreas, this technique has been utilized successfully to study acinar and endocrine islet cells. However, it has never been used to investigate ductal function. Since pancreatic ductal epithelial cells (PDECs) play an essential role in the physiology of the pancreas, our aim was to use this technique to study PDEC structure and function in situ. Materials and methods: Eight- to sixteen weeks old C57BL/6 mice were used for preparation of pancreas tissue slices. Low melting point agarose was injected into the common bile duct and the whole organ was extracted. For morphological studies, pieces of tissue were embedded in agarose and cryosectioned to obtain 15 μm thick slices. In order to visualize pancreatic ducts, (i) the Giemsa dye was added to the agarose and visualized using light microscopy or (ii) immunostaining for the cystic fibrosis transmembrane conductance regulator (CFTR) was performed. For functional characterization, agarose-embedded tissue was immediately cut to 140 μm thick tissue slices that were loaded with the cell permeant form of the Oregon Green 488 BAPTA-1 dye and used for confocal calcium imaging. Results: Giemsa staining has shown that the injected agarose reaches the head and body of the pancreas to a greater extent than the tail, without disrupting the tissue architecture. Strong CFTR expression was detected at the apical membranes of PDECs and acinar cells, whereas islet cells were completely negative for CFTR. Stimulation with chenodeoxycholic acid (CDCA, 1 mM) resulted in a robust transient increase in intracellular calcium concentration that was readily visible in >40 ductal cells per slice. Conclusion: Our results confirm that the acutely-isolated pancreas tissue slice technique is suitable for structural and functional investigation of PDECs and their relationship with other cell types, such as acini and endocrine cells in situ. In combination with different genetic, pharmacological or dietary approaches it could become a method of choice in the foreseeable future.

PMID: 31396104 [PubMed]

Burkholderia multivorans Exhibits Antibiotic Collateral Sensitivity.

Microb Drug Resist. 2019 Aug 08;:

Authors: Flanagan JN, Kavanaugh L, Steck TR

Abstract
Burkholderia multivorans is a member of the Burkholderia cepacia complex whose members are inherently resistant to many antibiotics and can cause chronic lung infections in patients with cystic fibrosis. A possible treatment for chronic infections arises from the existence of collateral sensitivity (CS)-acquired resistance to a treatment antibiotic results in a decreased resistance to a nontreatment antibiotic. Determining CS patterns for bacteria involved in chronic infections may lead to sustainable treatment regimens that reduce development of multidrug-resistant bacterial strains. CS has been found to occur in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Here, we report that B. multivorans exhibits antibiotic CS, as well as cross-resistance (CR), describe CS and CR networks for six antibiotics (ceftazidime, chloramphenicol, levofloxacin, meropenem, minocycline, and trimethoprim-sulfamethoxazole), and identify candidate genes involved in CS. Characterization of CS and CR patterns allows antibiotics to be separated into two clusters based on the treatment drug to which the evolved strain developed primary resistance, suggesting an antibiotic therapy strategy of switching between members of these two clusters.

PMID: 31393205 [PubMed - as supplied by publisher]

Home videos of cystic fibrosis patients using tobramycin inhalation powder: Relation of flow and cough.

Pediatr Pulmonol. 2019 Aug 08;:

Authors: Meerburg JJ, Albasri M, van der Wiel EC, Andrinopoulou ER, van der Eerden MM, Majoor CJ, Arets HGM, Heijerman HGM, Tiddens HAWM

Abstract
BACKGROUND: Many cystic fibrosis (CF) patients chronically infected with Pseudomonas aeruginosa are on maintenance tobramycin inhalation therapy. Cough is reported as a side effect of tobramycin inhalation powder (TIP) in 48% of the patients. Objectives of this study were to investigate the association between the inspiratory flow of TIP and cough and to study the inhalation technique. We hypothesized that cough is related to a fast inhalation.
MATERIALS AND METHODS: In this prospective observational study, CF patients ≥ 6 years old on TIP maintenance therapy from four Dutch CF centers were visited twice at home. Video recordings were obtained and peak inspiratory flow (PIF) was recorded while patients inhaled TIP. Between the two home visits, the patients made three additional videos. CF questionnaire-revised, spirometry data, and computed tomography scan were collected. Two observers scored the videos for PIF, cough, and mistakes in inhalation technique. The associations between PIF and cough were analyzed using a logistic mixed-effects model accounting for FEV1 % predicted and capsule number.
RESULTS: Twenty patients were included, median age 22 (18-28) years. No significant associations were found between PIF and cough. The risk of cough was highest after inhalation of the first capsule when compared to the second, third, and fourth capsule (P ≤ .015). Fourteen patients (70%) coughed at least once during TIP inhalation. A breath-hold of less than 5 seconds after inhalation and no deep expiration before inhalation were the most commonly observed mistakes.
CONCLUSION: PIF is not related to cough in CF patients using TIP.

PMID: 31393073 [PubMed - as supplied by publisher]