Cystic Fibrosis

Lung Inflammatory Environments Differentially Alter Mesenchymal Stromal Cell Behavior.

Thu, 2019-09-26 06:11

Lung Inflammatory Environments Differentially Alter Mesenchymal Stromal Cell Behavior.

Am J Physiol Lung Cell Mol Physiol. 2019 Sep 25;:

Authors: Abreu SC, Enes SR, Dearborn J, Goodwin M, Coffey A, Borg ZD, Dos Santos CC, Wargo MJ, Cruz FF, Loi R, DeSarno M, Ashikaga T, Antunes MA, Rocco PRM, Liu KD, Lee JW, Matthay MA, McKenna DH, Weiss DJ

Abstract
Mesenchymal stromal (stem) cells (MSCs) are increasingly demonstrated to ameliorate experimentally-induced lung injuries through disease-specific anti-inflammatory actions, thus suggesting that different in vivo inflammatory environments can influence MSC actions. To determine the effects of different representative inflammatory lung conditions, human bone marrow-derived MSCs (hMSCs) were exposed to in vitro culture conditions from bronchoalveolar lavage fluid (BALF) samples obtained from patients with either the acute respiratory distress syndrome (ARDS) or with other lung diseases including acute respiratory exacerbations of cystic fibrosis (CF) (non-ARDS). hMSCs were subsequently assessed for time- and BALF concentration-dependent effects on mRNA expression of selected pro- and anti-inflammatory mediators, and for overall patterns of gene and mRNA expression. Both common and disease specific-patterns were observed in gene expression of different hMSC mediators, notably interleukin (IL)-6. Conditioned media obtained from non-ARDS BALF-exposed hMSCs was more effective in promoting an anti-inflammatory phenotype in monocytes than was conditioned media from ARDS BALF-exposed hMSCs. Neutralizing IL-6 in the conditioned media promoted generation of anti-inflammatory monocyte phenotype. These results demonstrated that different lung inflammatory environments differentially alter hMSC behavior. Further identification of these interactions and the driving mechanisms may influence clinical use of MSCs for treating lung diseases.

PMID: 31553626 [PubMed - as supplied by publisher]

Categories: Literature Watch

Genomic and phenotypic comparison of environmental and patient-derived isolates of Pseudomonas aeruginosa suggest that antimicrobial resistance is rare within the environment.

Thu, 2019-09-26 06:11

Genomic and phenotypic comparison of environmental and patient-derived isolates of Pseudomonas aeruginosa suggest that antimicrobial resistance is rare within the environment.

J Med Microbiol. 2019 Sep 25;:

Authors: Ramsay KA, Wardell SJT, Patrick WM, Brockway B, Reid DW, Winstanley C, Bell SC, Lamont IL

Abstract
Patient-derived isolates of the opportunistic pathogen Pseudomonas aeruginosa are frequently resistant to antibiotics due to the presence of sequence variants in resistance-associated genes. However, the frequency of antibiotic resistance and of resistance-associated sequence variants in environmental isolates of P. aeruginosa has not been well studied. Antimicrobial susceptibility testing (ciprofloxacin, ceftazidime, meropenem, tobramycin) of environmental (n=50) and cystic fibrosis (n=42) P. aeruginosa isolates was carried out. Following whole genome sequencing of all isolates, 25 resistance-associated genes were analysed for the presence of likely function-altering sequence variants. Environmental isolates were susceptible to all antibiotics with one exception, whereas patient-derived isolates had significant frequencies of resistance to each antibiotic and a greater number of likely resistance-associated genetic variants. These findings indicate that the natural environment does not act as a reservoir of antibiotic-resistant P. aeruginosa, supporting a model in which antibiotic susceptible environmental bacteria infect patients and develop resistance during infection.

PMID: 31553303 [PubMed - as supplied by publisher]

Categories: Literature Watch

Pepsin Triggers Neutrophil Migration Across Acid Damaged Lung Epithelium.

Thu, 2019-09-26 06:11
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Pepsin Triggers Neutrophil Migration Across Acid Damaged Lung Epithelium.

Sci Rep. 2019 Sep 24;9(1):13778

Authors: Hurley BP, Jugo RH, Snow RF, Samuels TL, Yonker LM, Mou H, Johnston N, Rosen R

Abstract
Pepsin represents a potential biomarker for extraesophageal reflux disease when detected in airways, however a direct role for pepsin in lung dysfunction has not been clearly established. Children experiencing gastroesophageal and extraesophageal reflux are often prescribed proton pump inhibitors (PPIs) to reduce gastric acid associated damage to esophageal and airway mucosa. The potential of pepsin and gastric fluid, from children that were either on or off PPI therapy, to cause inflammation and damage using a human in vitro co-culture model of the airway mucosa was evaluated herein. Exposure of the airway model to acidic solutions caused cellular damage and loss of viability, however, acid alone did not disrupt barrier integrity or instigate neutrophil trans-epithelial migration without pepsin. Gastric fluid from patients on PPI therapy exhibited only a slightly higher pH yet had significantly higher concentrations of pepsin and elicited more barrier disruption and neutrophil trans-epithelial migration compared to gastric fluid from patients off PPIs. Inflammatory and damaging responses observed with gastric fluid from patients on PPIs were largely driven by pepsin. These results indicate the potential for PPI usage to raise concentrations of pepsin in gastric fluid, which may enhance the pathological impact of micro-aspirations in children with extraesophageal reflux.

PMID: 31551494 [PubMed - in process]

Categories: Literature Watch

Short-term consequences of F508del-CFTR thermal instability on CFTR-dependent transepithelial currents in human airway epithelial cells.

Thu, 2019-09-26 06:11
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Short-term consequences of F508del-CFTR thermal instability on CFTR-dependent transepithelial currents in human airway epithelial cells.

Sci Rep. 2019 Sep 24;9(1):13729

Authors: Froux L, Coraux C, Sage E, Becq F

Abstract
Loss-of-function mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) channel in human airway epithelial cells are responsible for Cystic Fibrosis. A deleterious impact of physiological temperature on CFTR plasma membrane expression, residence and channel activity is characteristic of the most common and severe CF mutation, F508del. Using primary human F508del-airway epithelial cells and CF bronchial epithelial CFBE41o- cell lines expressing F508del- or WT-CFTR, we examined the effects of temperature (29 °C-39 °C) on the amplitude and stability of short-circuit CFTR-dependent currents over time and the efficiency of pharmacological strategies to stably restore F508del-CFTR function. We show that F508del-CFTR functional instability at 37 °C is not prevented by low temperature or VX-809 correction, genistein and VX-770 potentiators, nor by the combination VX-809/VX-770. Moreover, F508del-CFTR-dependent currents 30 minutes after CFTR activation at 37 °C did not significantly differ whether a potentiator was used or not. We demonstrate that F508del-CFTR function loss is aggravated at temperatures above 37 °C while limited by a small decrease of temperature and show that the more F508del-CFTR is stimulated, the faster the current loss happens. Our study highlights the existence of a temperature-dependent process inhibiting the function of F508del-CFTR, possibly explaining the low efficacy of pharmacological drugs in clinic.

PMID: 31551433 [PubMed - in process]

Categories: Literature Watch

Noninvasive Prenatal Diagnosis for Cystic Fibrosis: Implementation, Uptake, Outcome, and Implications.

Thu, 2019-09-26 06:11
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Noninvasive Prenatal Diagnosis for Cystic Fibrosis: Implementation, Uptake, Outcome, and Implications.

Clin Chem. 2019 Sep 24;:

Authors: Chandler NJ, Ahlfors H, Drury S, Mellis R, Hill M, McKay FJ, Collinson C, Hayward J, Jenkins L, Chitty LS

Abstract
BACKGROUND: Noninvasive prenatal diagnosis (NIPD) for monogenic disorders has a high uptake by families. Since 2013, our accredited public health service laboratory has offered NIPD for monogenic disorders, predominantly for de novo or paternally dominantly inherited mutations. Here we describe the extension of this service to include definitive NIPD for a recessive condition, cystic fibrosis (CF).
METHODS: Definitive NIPD for CF was developed using next-generation sequencing. Validation was performed on 13 cases from 10 families before implementation. All cases referred for CF NIPD were reviewed to determine turnaround times, genotyping results, and pregnancy outcomes.
RESULTS: Of 38 referrals, 36 received a result with a mean turnaround of 5.75 days (range, 3-11 days). Nine cases were initially inconclusive, with 3 reported unaffected because the low-risk paternal allele was inherited and 4 cases in which the high-risk paternal allele was inherited, receiving conclusive results following repeat testing. One case was inconclusive owing to a paternal recombination around the mutation site, and one case was uninformative because of no heterozygosity. Before 2016, 3 invasive referrals for CF were received annually compared with 38 for NIPD in the 24 months since offering a definitive NIPD service.
CONCLUSIONS: Timely and accurate NIPD for definitive prenatal diagnosis of CF is possible in a public health service laboratory. The method detects recombinations, and the service is well-received as evidenced by the significant increase in referrals. The bioinformatic approach is gene agnostic and will be used to expand the range of conditions tested for.

PMID: 31551312 [PubMed - as supplied by publisher]

Categories: Literature Watch

SPINK1, PRSS1, CTRC, and CFTR Genotypes Influence Disease Onset and Clinical Outcomes in Chronic Pancreatitis.

Thu, 2019-09-26 06:11
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SPINK1, PRSS1, CTRC, and CFTR Genotypes Influence Disease Onset and Clinical Outcomes in Chronic Pancreatitis.

Clin Transl Gastroenterol. 2018 11 12;9(11):204

Authors: Zou WB, Tang XY, Zhou DZ, Qian YY, Hu LH, Yu FF, Yu D, Wu H, Deng SJ, Lin JH, Zhao AJ, Zhao ZH, Wu HY, Zhu JH, Qian W, Wang L, Xin L, Wang MJ, Wang LJ, Fang X, He L, Masson E, Cooper DN, Férec C, Li ZS, Chen JM, Liao Z

Abstract
OBJECTIVES: Rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes have been strongly associated with a risk of developing chronic pancreatitis (CP). However, their potential impact on the age of disease onset and clinical outcomes, as well as their potential interactions with environmental risk factors, remain unclear. These issues are addressed here in a large Chinese CP cohort.
METHODS: We performed targeted next-generation sequencing of the four CP-associated genes in 1061 Han Chinese CP patients and 1196 controls. To evaluate gene-environment interactions, the patients were divided into three subgroups, idiopathic CP (ICP; n = 715), alcoholic CP (ACP; n = 206), and smoking-associated CP (SCP; n = 140). The potential impact of rare pathogenic variants on the age of onset of CP and clinical outcomes was evaluated using the Kaplan-Meier model.
RESULTS: We identified rare pathogenic genotypes involving the SPINK1, PRSS1, CTRC, and/or CFTR genes in 535 (50.42%) CP patients but in only 71 (5.94%) controls (odds ratio = 16.12; P < 0.001). Mutation-positive patients had significantly earlier median ages at disease onset and at diagnosis of pancreatic stones, diabetes mellitus and steatorrhea than mutation-negative ICP patients. Pathogenic genotypes were present in 57.1, 39.8, and 32.1% of the ICP, ACP, and SCP patients, respectively, and influenced age at disease onset and clinical outcomes in all subgroups.
CONCLUSIONS: We provide evidence that rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes significantly influence the age of onset and clinical outcomes of CP. Extensive gene-environment interactions were also identified.

PMID: 30420730 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Epidemiology of bronchiectasis in the UK: Findings from the British lung foundation's 'Respiratory health of the nation' project.

Wed, 2019-09-25 11:52

Epidemiology of bronchiectasis in the UK: Findings from the British lung foundation's 'Respiratory health of the nation' project.

Respir Med. 2019 Sep 17;158:21-23

Authors: Snell N, Gibson J, Jarrold I, Quint JK

Abstract
Key findings of this national survey of non-cystic fibrosis bronchiectasis epidemiology were that its prevalence, incidence and mortality have all increased over recent years; we estimate that around 212,000 people are currently living with bronchiectasis in the UK, very much higher than commonly quoted figures. Bronchiectasis is more common in females than males; 60% of diagnoses are made in the over-70 age group. Regional differences in prevalence, incidence, mortality, and hospital admission were identified. An intriguing finding was that bronchiectasis is more commonly diagnosed in the least deprived sections of the population, in contrast to other respiratory disorders.

PMID: 31550642 [PubMed - as supplied by publisher]

Categories: Literature Watch

Efficacy of Glutathione for Patients With Cystic Fibrosis: A Meta-analysis of Randomized-Controlled Studies.

Wed, 2019-09-25 11:52

Efficacy of Glutathione for Patients With Cystic Fibrosis: A Meta-analysis of Randomized-Controlled Studies.

Am J Rhinol Allergy. 2019 Sep 24;:1945892419878315

Authors: Zhao J, Huang W, Zhang S, Xu J, Xue W, He B, Zhang Y

PMID: 31550169 [PubMed - as supplied by publisher]

Categories: Literature Watch

Practice variation of genetic counselor engagement in the cystic fibrosis newborn screen-positive diagnostic resolution process.

Wed, 2019-09-25 11:52

Practice variation of genetic counselor engagement in the cystic fibrosis newborn screen-positive diagnostic resolution process.

J Genet Couns. 2019 Sep 24;:

Authors: Langfelder-Schwind E, Raraigh KS, Parad RB

Abstract
Families of infants with a positive newborn screen for cystic fibrosis (CFNBS+) have well-characterized genetic counseling needs, including understanding the implications of diagnostic categorization. However, degree of involvement of genetic counselors (GCs) in the CFNBS+ diagnostic resolution process varies. This project explored GC engagement with US CF care centers in the diagnostic resolution process for CFNBS+ infants. Surveys were emailed to 713 Cystic Fibrosis Foundation-accredited CF center directors and clinic coordinators and 4,517 GCs. Respondents from institutions providing CFNBS+ diagnostic resolution were categorized by level of engagement between the CF center and GC: GC is part of or embedded in CF center (GC-engaged); GC is independent of CF center but receives CFNBS+ referrals (GC-referral); GC is uninvolved (non-engaged)] in CF center or CFNBS+ diagnostic resolution process. Responses from 125 CF center directors and clinic coordinators (17.5%) and 174 GCs (3.8%) were received. Analysis targeted responses from 84 center directors and clinic coordinators and 52 GCs, estimated to represent 24%-48% and 29% of 175 pediatric CF care centers, respectively. Nearly 40% of CF center directors or clinic coordinators never refer CFNBS+ infants to GCs. Respondents from GC-engaged CF centers reported that GCs provide unique and valuable services, understand CF at a high level, improve efficiency of the CFNBS+ diagnostic resolution process, and should be part of the CF care team; respondents from non-engaged CF centers reported negative views of GCs' value and knowledge (all p < .05). GCs engaged with CF centers were more likely to report that their services were valued by and accessible to CF centers (both p < .05). At all levels of engagement with CF centers, GCs were comfortable discussing CF genotype-phenotype correlation, variants of unknown significance, quality of life, and therapies. These results highlight a need to address practice variation in CFNBS+ genetic counseling and improve access to GCs' services.

PMID: 31550062 [PubMed - as supplied by publisher]

Categories: Literature Watch

Fungal biofilm morphology impacts hypoxia fitness and disease progression.

Wed, 2019-09-25 11:52
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Fungal biofilm morphology impacts hypoxia fitness and disease progression.

Nat Microbiol. 2019 Sep 23;:

Authors: Kowalski CH, Kerkaert JD, Liu KW, Bond MC, Hartmann R, Nadell CD, Stajich JE, Cramer RA

Abstract
Microbial populations form intricate macroscopic colonies with diverse morphologies whose functions remain to be fully understood. Despite fungal colonies isolated from environmental and clinical samples revealing abundant intraspecies morphological diversity, it is unclear how this diversity affects fungal fitness and disease progression. Here we observe a notable effect of oxygen tension on the macroscopic and biofilm morphotypes of the human fungal pathogen Aspergillus fumigatus. A hypoxia-typic morphotype is generated through the expression of a subtelomeric gene cluster containing genes that alter the hyphal surface and perturb interhyphal interactions to disrupt in vivo biofilm and infection site morphologies. Consequently, this morphotype leads to increased host inflammation, rapid disease progression and mortality in a murine model of invasive aspergillosis. Taken together, these data suggest that filamentous fungal biofilm morphology affects fungal-host interactions and should be taken into consideration when assessing virulence and host disease progression of an isolated strain.

PMID: 31548684 [PubMed - as supplied by publisher]

Categories: Literature Watch

Validity and Reliability of Pediatric Nutrition Screening Tools for Hospital, Outpatient, and Community Settings: A 2018 Evidence Analysis Center Systematic Review.

Wed, 2019-09-25 11:52
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Validity and Reliability of Pediatric Nutrition Screening Tools for Hospital, Outpatient, and Community Settings: A 2018 Evidence Analysis Center Systematic Review.

J Acad Nutr Diet. 2019 Sep 20;:

Authors: Becker PJ, Gunnell Bellini S, Wong Vega M, Corkins MR, Spear BA, Spoede E, Hoy MK, Piemonte TA, Rozga M

Abstract
BACKGROUND: Nutrition screening tools are used to identify risk of malnutrition or change in risk of malnutrition. However, it is unclear which tools have demonstrated high validity, reliability, and agreement.
OBJECTIVE: Our aim was to conduct a systematic review of valid and reliable pediatric nutrition screening tools for identifying malnutrition risk (under- or overnutrition), and to determine whether there are differences in validity and reliability according to users of the tools.
METHODS: A literature search using Medline, Embase, and CINAHL databases was conducted to identify relevant research published between 1995 and May 2017 examining validity and reliability of nutrition screening tools in the pediatric population. A multidisciplinary workgroup developed eligibility criteria, data were extracted and summarized, risk of bias was assessed, and evidence strength was graded, according to a standard process.
RESULTS: Twenty-nine studies met inclusion criteria. Thirteen pediatric nutrition screening tools designed for various settings were included in the review (seven inpatient/hospital, three outpatient or specialty setting, and three community). The most frequently examined tools were the Screening Tool for the Assessment of Malnutrition in Pediatrics, Screening Tool for Risk on Nutritional Status and Growth (13 studies each), and Paediatric Yorkhill Malnutrition Score (nine studies). No tools demonstrated high validity. Reliability and agreement were reported infrequently.
CONCLUSIONS: Nutrition screening tools with good/strong or fair evidence and moderate validity included the Screening Tool for the Assessment of Malnutrition in Pediatrics, Screening Tool for Risk on Nutritional Status and Growth, and Paediatric Yorkhill Malnutrition Score in the inpatient setting and Nutrition Risk Screening Tool for Children and Adolescents with Cystic Fibrosis in the specialty setting. No tools in the community setting met these criteria. While differences in validity and reliability measures among tool users were found, the significance of these findings is unclear. Limitations included few studies examining each tool, heterogeneity between studies examining a common tool, and lack of tools that included currently recommended indicators to identify pediatric malnutrition.

PMID: 31547992 [PubMed - as supplied by publisher]

Categories: Literature Watch

The Effect of 2-Thiocyanatopyridine Derivative 11026103 on Burkholderia Cenocepacia: Resistance Mechanisms and Systemic Impact.

Wed, 2019-09-25 11:52
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The Effect of 2-Thiocyanatopyridine Derivative 11026103 on Burkholderia Cenocepacia: Resistance Mechanisms and Systemic Impact.

Antibiotics (Basel). 2019 Sep 21;8(4):

Authors: Nunvar J, Hogan AM, Buroni S, Savina S, Makarov V, Cardona ST, Drevinek P

Abstract
Bacteria of the Burkholderia cepacia complex (Bcc) are associated with significant decline of lung functions in cystic fibrosis patients. Bcc infections are virtually impossible to eradicate due to their irresponsiveness to antibiotics. The 2-thiocyanatopyridine derivative 11026103 is a novel, synthetic compound active against Burkholderia cenocepacia. To characterize mechanisms of resistance to 11026103, B. cenocepacia was subjected to chemical mutagenesis, followed by whole genome sequencing. Parallel mutations in resistant isolates were localized in a regulatory protein of the efflux system Resistance-Nodulation-Division (RND)-9 (BCAM1948), RNA polymerase sigma factor (BCAL2462) and its cognate putative anti-sigma factor (BCAL2461). Transcriptomic analysis identified positive regulation of a major facilitator superfamily (MFS) efflux system BCAL1510-1512 by BCAL2462. Artificial overexpression of both efflux systems increased resistance to the compound. The effect of 11026103 on B. cenocepacia was analyzed by RNA-Seq and a competitive fitness assay utilizing an essential gene knockdown mutant library. 11026103 exerted a pleiotropic effect on transcription including profound downregulation of cluster of orthologous groups (COG) category "Translation, ribosomal structure, and biogenesis". The competitive fitness assay identified many genes which modulated susceptibility to 11026103. In summary, 11026103 exerts a pleiotropic cellular response in B. cenocepacia which can be prevented by efflux system-mediated export.

PMID: 31546596 [PubMed]

Categories: Literature Watch

Evaluation of hospitalization data for the CFFPR-PHIS linked data set.

Tue, 2019-09-24 08:17
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Evaluation of hospitalization data for the CFFPR-PHIS linked data set.

Pediatr Pulmonol. 2019 Sep 22;:

Authors: Cogen JD, Faino AV, Onchiri F, Hall M, Fink AK

PMID: 31544363 [PubMed - as supplied by publisher]

Categories: Literature Watch

Does partitioning the subcomponents of the ventilatory equivalent for carbon dioxide slope provide evidence that ventilatory efficiency is retained in cystic fibrosis?

Tue, 2019-09-24 08:17
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Does partitioning the subcomponents of the ventilatory equivalent for carbon dioxide slope provide evidence that ventilatory efficiency is retained in cystic fibrosis?

Pediatr Pulmonol. 2019 Sep 23;:

Authors: Van Iterson EH, Snyder EM

PMID: 31544352 [PubMed - as supplied by publisher]

Categories: Literature Watch

Differential effects of membrane sphingomyelin and cholesterol on agonist-induced bitter taste receptor T2R14 signaling.

Sun, 2019-09-22 07:32
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Differential effects of membrane sphingomyelin and cholesterol on agonist-induced bitter taste receptor T2R14 signaling.

Mol Cell Biochem. 2019 Sep 20;:

Authors: Shaik FA, Chelikani P

Abstract
Membrane lipids regulate the structure and function of G protein-coupled receptors (GPCRs). Previously we have shown that membrane cholesterol regulates the signaling of two human bitter taste receptors (T2Rs), T2R4 and T2R14. Another major plasma membrane lipid known to influence the function of membrane proteins including GPCRs is sphingomyelin. The role of sphingomyelin in T2R function is unexplored thus far. In this work, we examined the significance of sphingomyelin in T2R14 signaling. Results suggest that unavailability of membrane sphingomyelin did not affect the agonist-promoted T2R14 Ca2+ signaling in heterologous expression system and also in primary airway smooth muscle cells (HASM cells). In addition, T2R14 mediated downstream AMPK activation was also unaffected in sphingomyelin-depleted condition; however, cholesterol depletion impaired the T2R14-mediated AMPK activation. Angiotensin II type1A receptor (AT1R) expressed in HASM cells and signals through Ca2+ and AMPK was used as a control. Results suggest that similar to T2R14, membrane sphingomyelin depletion did not affect AT1R signaling. However, membrane cholesterol depletion impaired AT1R mediated Ca2+ signaling and AMPK activation. Interestingly, amino acid sequence analysis revealed the presence of putative sphingolipid binding motif in both T2R14 and AT1R suggesting that the presence of a motif alone might not be suggestive of sphingomyelin sensitivity. In conclusion, these results demonstrate that in contrast to membrane cholesterol, sphingomyelin does not affect the agonist-induced T2R14 signaling, however it may play a role in other aspects of T2R14 function.

PMID: 31541354 [PubMed - as supplied by publisher]

Categories: Literature Watch

RNA-based qPCR as a tool to quantify and to characterize dual-species biofilms.

Sun, 2019-09-22 07:32
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RNA-based qPCR as a tool to quantify and to characterize dual-species biofilms.

Sci Rep. 2019 Sep 20;9(1):13639

Authors: Magalhães AP, França Â, Pereira MO, Cerca N

Abstract
While considerable research has focused on studying individual-species, we now face the challenge of determining how interspecies interactions alter bacterial behaviours and pathogenesis. Pseudomonas aeruginosa and Staphylococcus aureus are often found to co-infect cystic-fibrosis patients. Curiously, their interaction is reported as competitive under laboratory conditions. Selecting appropriate methodologies is therefore critical to analyse multi-species communities. Herein, we demonstrated the major biases associated with qPCR quantification of bacterial populations and optimized a RNA-based qPCR able not only to quantify but also to characterize microbial interactions within dual-species biofilms composed by P. aeruginosa and S. aureus, as assessed by gene expression quantification. qPCR quantification was compared with flow-cytometry and culture-based quantification. Discrepancies between culture independent and culture dependent methods could be the result of the presence of viable but not-cultivable bacteria within the biofilm. Fluorescence microscopy confirmed this. A higher sensitivity to detect viable cells further highlights the potentialities of qPCR approach to quantify biofilm communities. By using bacterial RNA and an exogenous mRNA control, it was also possible to characterize bacterial transcriptomic profile, being this a major advantage of this method.

PMID: 31541147 [PubMed - in process]

Categories: Literature Watch

Cigarette Smoke Exposure Induces Retrograde Trafficking of CFTR to the Endoplasmic Reticulum.

Sun, 2019-09-22 07:32
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Cigarette Smoke Exposure Induces Retrograde Trafficking of CFTR to the Endoplasmic Reticulum.

Sci Rep. 2019 Sep 20;9(1):13655

Authors: Marklew AJ, Patel W, Moore PJ, Tan CD, Smith AJ, Sassano MF, Gray MA, Tarran R

Abstract
Chronic obstructive pulmonary disease (COPD), which is most commonly caused by cigarette smoke (CS) exposure, is the third leading cause of death worldwide. The cystic fibrosis transmembrane conductance regulator (CFTR) is an apical membrane anion channel that is widely expressed in epithelia throughout the body. In the airways, CFTR plays an important role in fluid homeostasis and helps flush mucus and inhaled pathogens/toxicants out of the lung. Inhibition of CFTR leads to mucus stasis and severe airway disease. CS exposure also inhibits CFTR, leading to the decreased anion secretion/hydration seen in COPD patients. However, the underlying mechanism is poorly understood. Here, we report that CS causes CFTR to be internalized in a clathrin/dynamin-dependent fashion. This internalization is followed by retrograde trafficking of CFTR to the endoplasmic reticulum. Although this internalization pathway has been described for bacterial toxins and cargo machinery, it has never been reported for mammalian ion channels. Furthermore, the rapid internalization of CFTR is dependent on CFTR dephosphorylation by calcineurin, a protein phosphatase that is upregulated by CS. These results provide new insights into the mechanism of CFTR internalization, and may help in the development of new therapies for CFTR correction and lung rehydration in patients with debilitating airway diseases such as COPD.

PMID: 31541117 [PubMed - in process]

Categories: Literature Watch

The identification of loci that encode potentially active compounds against drug resistant pathogens amidst a decreasing pool of novel antibiotics.

Sun, 2019-09-22 07:32
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The identification of loci that encode potentially active compounds against drug resistant pathogens amidst a decreasing pool of novel antibiotics.

Appl Environ Microbiol. 2019 Sep 20;:

Authors: Basalla J, Chatterjee P, Burgess E, Khan M, Verbrugge E, Wiegmann DD, LiPuma J, Wildschutte H

Abstract
Since the discovery of penicillin, microbes have been a source of antibiotics that inhibit the growth of pathogens. However, with the evolution of multi-drug resistant (MDR) strains, it remains unclear if there is an abundant or limited supply of natural products to be discovered that are effective against MDR isolates. To identify strains that are antagonistic to pathogens, we examined a set of 471 globally derived environmental Pseudomonas strains (env-Ps) for activity against a panel of 65 pathogens including Achromobacter spp., Burkholderia spp., Pseudomonas aeruginosa, and Stenotrophomonas spp. isolated from the lungs of cystic fibrosis (CF) patients. From more than 30,000 competitive interactions, 1,530 individual inhibitory events were observed. While strains from water habitats were not proportionate in antagonistic activity, MDR CF-derived pathogens (CF-Ps) were less susceptible to inhibition by env-Ps, suggesting that fewer natural products are effective against MDR strains. These results advocate for a directed strategy to identify unique drugs. To facilitate antibiotic discovery against the most resistant pathogens, we developed a workflow in which phylogenetic and antagonistic data were merged to identify strains that inhibit MDR CF-Ps and subjected those env-Ps to transposon mutagenesis. Six different biosynthetic gene clusters (BGCs) were identified from four strains whose products inhibited pathogens including carbapenem-resistant P. aeruginosa BGCs were rare in databases suggesting the production of novel antibiotics. This strategy can be utilized to facilitate the discovery of needed antibiotics that are potentially active against the most drug resistant pathogens.Importance Carbapenem-resistant P. aeruginosa is difficult to treat and has been deemed by the World Health Organization as a priority one pathogen for which antibiotics are most urgently needed. Although metagenomics and bioinformatic studies suggest natural bacteria remain a source of novel compounds, the identification of genes and their products specific to activity against MDR pathogens remains problematic. Here, we examine water-derived pseudomonads and identify gene clusters whose compounds inhibit CF-derived MDR pathogens including carbapenem-resistant P. aeruginosa.

PMID: 31540982 [PubMed - as supplied by publisher]

Categories: Literature Watch

Variations in prenatal screening in a US federal healthcare system: Same coverage, different options.

Sat, 2019-09-21 07:02
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Variations in prenatal screening in a US federal healthcare system: Same coverage, different options.

J Genet Couns. 2019 Sep 19;:

Authors: Thagard AS, Foglia LM, Staat BL, Lutgendorf MA

Abstract
The Military Health System (MHS) is a federally funded organization that provides care to active duty service members and their beneficiaries. Our objective was to determine what methods of prenatal screening are used by military treatment facilities (MTFs), assess variations between institutions, and determine how practice patterns align with national recommendations. We surveyed all MTFs offering comprehensive prenatal care (n = 49). Departments were asked about aneuploidy screening options, availability of diagnostic testing, and carrier screening. In all, 43 MTFs (88%) completed the survey. Most (39/43) patients were stratified based on risk (predominantly maternal age at delivery and history). The most commonly offered test was combined 1st/2nd trimester screening (59%). Sixty percent routinely offered diagnostic testing, though less than half routinely offered microarrays. The majority offered universal carrier screening for cystic fibrosis (98%) and complete blood count with screening for thalassemias and hemoglobinopathies (88%). At the time of data collection, only five facilities (12%) had implemented spinal muscular atrophy carrier screening. Considerable heterogeneity exists in prenatal aneuploidy testing and carrier screening within the MHS. Standardized guidelines, protocols, and laboratory support would improve processes across the system. Additional resources including genetic counseling support and provider education are needed.

PMID: 31538382 [PubMed - as supplied by publisher]

Categories: Literature Watch

Guidance for computed tomography (CT) imaging of the lungs for patients with cystic fibrosis (CF) in research studies.

Sat, 2019-09-21 07:02
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Guidance for computed tomography (CT) imaging of the lungs for patients with cystic fibrosis (CF) in research studies.

J Cyst Fibros. 2019 Sep 16;:

Authors: van Straten M, Brody AS, Ernst C, Guillerman RP, Tiddens HAWM, Nagle SK

Abstract
Numerous issues must be addressed when developing standard operating procedures for clinical research studies involving chest computed tomography of lung disease in patients with cystic fibrosis (CF). Study success depends on the provision of adequate funding and the identification of personnel with the necessary expertise to conduct the study, along with clear guidelines that detail the CT operating procedure at each site, including breathing maneuvers, and image reconstruction. Close coordination of the quality assurance process between sites and the central review organization is required to maintain protocol adherence. The data transfer process must ensure the integrity and security of the data to comply with patient privacy regulations, and study outcome measures are best assessed with a scoring system or other structured method of imaging data analysis. The recommendations provided are designed to serve as a valuable reference guide for planning clinical research studies of patients with CF involving chest CT.

PMID: 31537430 [PubMed - as supplied by publisher]

Categories: Literature Watch

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