Could a defective epithelial sodium channel lead to bronchiectasis

<p>Abstract</p> <p>Background</p> <p>Bronchiectasis is defined as a permanent dilation of the airways arising from chronic bronchial inflammation/infection. In 50% of cases, no etiology can be identified. Recently, the role of the epithelial sodium channel ENaC has been pointed out in the pathophysiology of cystic fibrosis, a disease due to mutations in the <it>CFTR </it>gene and causing bronchiectasis in the airways. Moreover, it was found that transgenic mice overexpressing <it>ENaCβ </it>present cystic fibrosis-like lung disease symptoms. Our aim was to evaluate if a defective ENaC protein could be involved in the development of bronchiectasis.</p> <p>Methods</p> <p>We extensively analysed <it>ENaCβ </it>and <it>γ </it>genes in 55 patients with idiopathic bronchiectasis and without two mutations in the coding regions of <it>CFTR</it>. Thirty-eight patients presented functional abnormalities suggesting impaired sodium transport (abnormal sweat chloride concentration or nasal potential difference measurement), and 17 had no such evidence.</p> <p>Results</p> <p>Sequencing of the exons and flanking introns of the <it>ENaCβ </it>and <it>γ </it>gene identified five different amino-acid changes (p.Ser82Cys, p.Pro369Thr, p.Asn288Ser in <it>ENaCβ </it>; and p.Gly183Ser, p.Glu197Lys in <it>ENaCγ</it>) in heterozygous state in 8 patients. The p.Ser82Cys amino-acid change was found in 3 unrelated patients who were also heterozygous for a <it>CFTR </it>mutation or variant (1 p.F508del, 1 IVS8-5T, and 1 IVS8-5T:1716G>A (p.E528E)). The other mutations were found in patients without <it>CFTR </it>mutation, the p.Glu197Lys mutation in 2 patients and the other variants in single patients. Among the 8 patients bearing an <it>ENaC </it>mutation, 5 had functional abnormalities suggesting impaired sodium transport.</p> <p>Conclusion</p> <p>Our results suggest that several variants in <it>ENaCβ </it>and <it>γ </it>genes might be deleterious for ENaC function and lead to bronchiectasis, especially in patients who are trans-heterozygotes for <it>ENaCβ/CFTR </it>mutations or variants.</p

Allozyme differentiation of two populations of the genus Neoplecostomus Eigenmann & Eigenmann, 1888 (Teleostei, Loricariidae) from the upper Paraná River basin, Brazil

Allozyme electrophoresis was used to examine 12 enzymatic systems in two populations of the genus Neoplecostomus from the Paraná River basin. Samples of Neoplecostomus sp. 1 were collected in Paraitinguinha stream of the Tietê River basin, in the municipality of Salesópolis, São Paulo State, and those of Neoplecostomus sp. 2 from São Domingos stream of the Rio Grande River basin, in the municipality of Muzambinho, Minas Gerais State. The genetic variability of the two populations was estimated by Nei’s expected heterozygosity and was considered lower than average for populations of freshwater fish. The proportion of polymorphic loci was low (only 5.26% for the locus Idh). The low frequency of heterozygosity for both populations revealed a high fixation of alleles for each locus. Homozygote excess was observed in both populations. The values of Nei’s genetic identity and the presence of loci with different allele frequencies in both populations may imply that the two populations belong to different species. The genetic variability between populations was compared to other data for loricariids

The economic burden of bronchiectasis - known and unknown:a systematic review

Abstract Background The increasing prevalence and recognition of bronchiectasis in clinical practice necessitates a better understanding of the economic disease burden to improve the management and achieve better clinical and economic outcomes. This study aimed to assess the economic burden of bronchiectasis based on a review of published literature. Methods A systematic literature review was conducted using MEDLINE, Embase, EconLit and Cochrane databases to identify publications (1 January 2001 to 31 December 2016) on the economic burden of bronchiectasis in adults. Results A total of 26 publications were identified that reported resource use and costs associated with management of bronchiectasis. Two US studies reported annual incremental costs of bronchiectasis versus matched controls of US$5681 and US$2319 per patient. Twenty-four studies reported on hospitalization rates or duration of hospitalization for patients with bronchiectasis. Mean annual hospitalization rates per patient, reported in six studies, ranged from 0.3–1.3, while mean annual age-adjusted hospitalization rates, reported in four studies, ranged from 1.8–25.7 per 100,000 population. The average duration of hospitalization, reported in 12 studies, ranged from 2 to 17 days. Eight publications reported management costs of bronchiectasis. Total annual management costs of €3515 and €4672 per patient were reported in two Spanish studies. Two US studies reported total costs of approximately US$26,000 in patients without exacerbations, increasing to US$36,00–37,000 in patients with exacerbations. Similarly, a Spanish study reported higher total annual costs for patients with > 2 exacerbations per year (€7520) compared with those without exacerbations (€3892). P. aeruginosa infection increased management costs by US$31,551 to US$56,499, as reported in two US studies, with hospitalization being the main cost driver. Conclusions The current literature suggests that the economic burden of bronchiectasis in society is significant. Hospitalization costs are the major driver behind these costs, especially in patients with frequent exacerbations. However, the true economic burden of bronchiectasis is likely to be underestimated because most studies were retrospective, used ICD-9-CM coding to identify patients, and often ignored outpatient burden and cost. We present a conceptual framework to facilitate a more comprehensive assessment of the true burden of bronchiectasis for individuals, healthcare systems and society

A 2 × 2 factorial, randomised, open-label trial to determine the clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care over 52 weeks in adults with bronchiectasis:a protocol for the CLEAR clinical trial

Background: Current guidelines for the management of bronchiectasis (BE) highlight the lack of evidence to recommend mucoactive agents, such as hypertonic saline (HTS) and carbocisteine, to aid sputum removal as part of standard care. We hypothesise that mucoactive agents (HTS or carbocisteine, or a combination) are effective in reducing exacerbations over a 52-week period, compared to usual care. Methods: This is a 52-week, 2 × 2 factorial, randomized, open-label trial to determine the clinical effectiveness and cost effectiveness of HTS 6% and carbocisteine for airway clearance versus usual care-the Clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care (CLEAR) trial. Patients will be randomised to (1) standard care and twice-daily nebulised HTS (6%), (2) standard care and carbocisteine (750 mg three times per day until visit 3, reducing to 750 mg twice per day), (3) standard care and combination of twice-daily nebulised HTS and carbocisteine, or (4) standard care. The primary outcome is the mean number of exacerbations over 52 weeks. Key inclusion criteria are as follows: Adults with a diagnosis of BE on computed tomography, BE as the primary respiratory diagnosis, and two or more pulmonary exacerbations in the last year requiring antibiotics and production of daily sputum. Discussion: This trial's pragmatic research design avoids the significant costs associated with double-blind trials whilst optimising rigour in other areas of trial delivery. The CLEAR trial will provide evidence as to whether HTS, carbocisteine or both are effective and cost effective for patients with BE. Trial registration: EudraCT number: 2017-000664-14 (first entered in the database on 20 October 2017). ISRCTN.com, ISRCTN89040295. Registered on 6 July/2018. Funder: National Institute for Health Research, Health Technology Assessment Programme (15/100/01). Sponsor: Belfast Health and Social Care Trust. Ethics Reference Number: 17/NE/0339. Protocol version: V3.0 Final_14052018

Current Status of a Model System: The Gene Gp-9 and Its Association with Social Organization in Fire Ants

The Gp-9 gene in fire ants represents an important model system for studying the evolution of social organization in insects as well as a rich source of information relevant to other major evolutionary topics. An important feature of this system is that polymorphism in social organization is completely associated with allelic variation at Gp-9, such that single-queen colonies (monogyne form) include only inhabitants bearing B-like alleles while multiple-queen colonies (polygyne form) additionally include inhabitants bearing b-like alleles. A recent study of this system by Leal and Ishida (2008) made two major claims, the validity and significance of which we examine here. After reviewing existing literature, analyzing the methods and results of Leal and Ishida (2008), and generating new data from one of their study sites, we conclude that their claim that polygyny can occur in Solenopsis invicta in the U.S.A. in the absence of expression of the b-like allele Gp-9b is unfounded. Moreover, we argue that available information on insect OBPs (the family of proteins to which GP-9 belongs), on the evolutionary/population genetics of Gp-9, and on pheromonal/behavioral control of fire ant colony queen number fails to support their view that GP-9 plays no role in the chemosensory-mediated communication that underpins regulation of social organization. Our analyses lead us to conclude that there are no new reasons to question the existing consensus view of the Gp-9 system outlined in Gotzek and Ross (2007)