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Cystic fibrosis [keywords]
- Novosphingobium and Its Potential Role in Chronic Obstructive Pulmonary Diseases: Insights from Microbiome Studies. [JOURNAL ARTICLE]
- PLoS One 2014; 9(10):e111150.
Bacterial infection of lung airways underlies some of the main complications of COPD, significantly impacting disease progression and outcome. Colonization by bacteria may further synergize, amplify, or trigger pathways of tissue damage started by cigarette smoke, contributing to the characteristic airway inflammation and alveolar destruction of COPD. We sought to elucidate the presence and types of lung bacterial populations in different stages of COPD, aimed at revealing important insights into the pathobiology of the disease. Sequencing of the bacterial small subunit ribosomal RNA gene in 55 well-characterized clinical lung samples, revealed the presence of Novosphingobium spp. (>2% abundance) in lungs of patients with GOLD 3-GOLD 4 COPD, cystic fibrosis and a subset of control individuals. Novosphingobium-specific quantitative PCR was concordant with the sequence data and high levels of Novosphingobium spp. were quantifiable in advanced COPD, but not from other disease stages. Using a mouse model of subacute lung injury due to inhalation of cigarette smoke, bronchoalveolar lavage neutrophil and macrophage counts were significantly higher in mice challenged intratracheally with N. panipatense compared to control mice (p<0.01). Frequencies of neutrophils and macrophages in lung tissue were increased in mice challenged with N. panipatense at room air compared to controls. However, we did not observe an interaction between N. panipatense and subacute cigarette smoke exposure in the mouse. In conclusion, Novosphingobium spp. are present in more severe COPD disease, and increase inflammation in a mouse model of smoke exposure.
- A prospective cohort study of the use of domiciliary intravenous antibiotics in bronchiectasis. [JOURNAL ARTICLE]
- NPJ Prim Care Respir Med 2014.:14090.
Background:We introduced domiciliary intravenous (IV) antibiotic therapy in patients with bronchiectasis to promote patient-centred domiciliary treatment instead of hospital inpatient treatment.Aim:To assess the efficacy and safety of domiciliary IV antibiotic therapy in patients with non-cystic fibrosis bronchiectasis.Methods:In this prospective study conducted over 5 years, we assessed patients' eligibility for receiving domiciliary treatment. All patients received 14 days of IV antibiotic therapy and were monitored at baseline/day 7/day 14. We assessed the treatment outcome, morbidity, mortality and 30-day readmission rates.Results:A total of 116 patients received 196 courses of IV antibiotics. Eighty courses were delivered as inpatient treatment, 32 as early supported discharge (ESD) and 84 as domiciliary therapy. There was significant clinical and quality of life improvement in all groups, with resolution of infection in 76% in the inpatient group, 80% in the ESD group and 80% in the domiciliary group. Morbidity was recorded in 13.8% in the inpatient group, 9.4% in the ESD group and 14.2% in the domiciliary IV group. No mortality was recorded in either group. Thirty-day readmission rates were 13.8% in the inpatient group, 12.5% in the ESD group and 14.2% in the domiciliary group. Total bed days saved was 1443.Conclusion:Domiciliary IV antibiotic therapy in bronchiectasis is clinically effective and was safe in our cohort of patients.
- Candida albicans Ethanol Stimulates Pseudomonas aeruginosa WspR-Controlled Biofilm Formation as Part of a Cyclic Relationship Involving Phenazines. [JOURNAL ARTICLE]
- PLoS Pathog 2014 Oct; 10(10):e1004480.
In chronic infections, pathogens are often in the presence of other microbial species. For example, Pseudomonas aeruginosa is a common and detrimental lung pathogen in individuals with cystic fibrosis (CF) and co-infections with Candida albicans are common. Here, we show that P. aeruginosa biofilm formation and phenazine production were strongly influenced by ethanol produced by the fungus C. albicans. Ethanol stimulated phenotypes that are indicative of increased levels of cyclic-di-GMP (c-di-GMP), and levels of c-di-GMP were 2-fold higher in the presence of ethanol. Through a genetic screen, we found that the diguanylate cyclase WspR was required for ethanol stimulation of c-di-GMP. Multiple lines of evidence indicate that ethanol stimulates WspR signaling through its cognate sensor WspA, and promotes WspR-dependent activation of Pel exopolysaccharide production, which contributes to biofilm maturation. We also found that ethanol stimulation of WspR promoted P. aeruginosa colonization of CF airway epithelial cells. P. aeruginosa production of phenazines occurs both in the CF lung and in culture, and phenazines enhance ethanol production by C. albicans. Using a C. albicans adh1/adh1 mutant with decreased ethanol production, we found that fungal ethanol strongly altered the spectrum of P. aeruginosa phenazines in favor of those that are most effective against fungi. Thus, a feedback cycle comprised of ethanol and phenazines drives this polymicrobial interaction, and these relationships may provide insight into why co-infection with both P. aeruginosa and C. albicans has been associated with worse outcomes in cystic fibrosis.
- [Mycobacterial lung disease in patients with cystic fibrosis - report of three cases]. [English Abstract, Journal Article]
- Pneumonol Alergol Pol 2014; 82(6):561-7.
Mycobacterial lung disease is caused by nontuberculous mycobacteria (NTM), also known as atypical mycobacteria. NTM are widely distributed in the environment, particularly in soil and water. Although generally of low pathogenicity to humans, NTM can affect patients with underlying chronic lung diseases, such as cystic fibrosis, bronchiectasis, pneumoconiosis, or healed tuberculosis. Some patients with cystic fibrosis (CF) have disease progression due to NTM, others can have NTM cultured intermittently from respiratory specimens without a significant decline in lung function. Identifying which patients will worsen from NTM and therefore need treatment remains difficult because of the similarity of symptoms in CF and NTM lung disease. The most common species of NTM isolated in CF patients are Mycobacterium avium complex (MAC) and Mycobacterium abscessus. In this paper, we present three different cases of mycobacterial lung disease in patients with cystic fibrosis.
- The Pro-Apoptotic and Pro-Inflammatory Effects of Calprotectin on Human Periodontal Ligament Cells. [JOURNAL ARTICLE]
- PLoS One 2014; 9(10):e110421.
Calprotectin, a heterodimer of S100A8 and S100A9 subunits, is associated with inflammatory disorders such as rheumatoid arthritis and cystic fibrosis. Although calprotectin levels are increased significantly in the gingival crevicular fluid (GCF) of periodontitis patients, its effects on periodontal ligament cells (PDLCs) remain largely unknown. The aim of this study was to evaluate calprotectin levels in the GCF of generalized aggressive periodontitis (AgP) patients and to investigate the effects of recombinant human calprotectin (rhS100A8/A9) and its subunits (rhS100A8 and rhS100A9) in PDLCs. Both the concentration and amount of crevicular calprotectin were significantly higher in the AgP group compared with healthy controls. In addition, the GCF calprotectin levels were correlated positively with clinical periodontal parameters including bleeding index, probing depth, and clinical attachment loss. rhS100A8/A9 promoted cell apoptosis, whereas rhS100A8 and rhS100A9 individually exerted little effect on apoptosis in PDLCs. rhS100A9 and rhS100A8/A9 increased the activation of nuclear factor-κB (NF-κB) by promoting the nuclear translocation of p65 in PDLCs, subsequently inducing expression of the pro-inflammatory cytokines IL-6, IL-8, TNFα, and COX2. Treatment with an NF-κB inhibitor partially reversed the rhS100A9- and rhS100A8/A9-induced upregulation of the pro-inflammatory cytokines. rhS100A9, and not rhS100A8, was mainly responsible for the pro-inflammatory role of calprotectin. Collectively, our results suggest that calprotectin promotes apoptosis and the inflammatory response in PDLCs via rhS100A9. These findings might help identify novel treatments for periodontitis.
- Pneumothorax in cystic fibrosis. [Journal Article, Review]
- J Thorac Dis 2014 Oct; 6(Suppl 4):S480-7.
Pneumothorax is recognized as a common and life-threatening complication in cystic fibrosis (CF) patients, especially in those who are infected with P. aeruginosa, B. cepacia or Aspergillus, need enteral feeding, are diagnosed as suffering from allergic bronchopulmonary aspergillosis (ABPA), developed massive hemoptysis, and their respiratory function is seriously compromised. Structural impairment and altered airflow dynamics in the lungs of CF patients are considered as the main predisposing factors, but also inhaled medications and non-invasive positive pressure ventilation (NIPPV) could increase the risk of pneumothorax. Clinical presentation could range from dramatic to very mild. Management of spontaneous pneumothorax occurring to patients with CF is essentially similar to that for non-CF patients. Therapeutic options include intercostal tube drainage, video-assisted thoracoscopic surgery (VATS), and medical or surgical pleurodesis. Pneumothorax increases both short- and long-term morbidity and mortality in CF patients and causes significant deterioration of their quality of life.
- MANAGEMENT OF ENDOCRINE DISEASE: Cystic fibrosis-related diabetes: novel pathogenic insights opening new therapeutic avenues. [JOURNAL ARTICLE]
- Eur J Endocrinol 2014 Oct 21.
Cystic fibrosis (CF) is a recessive genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR). CFTR is primarily present in epithelial cells of the airways, intestine and in cells with exocrine and endocrine functions. Mutations in the gene encoding the channel protein complex (CFTR) cause alterations in the ionic composition of secretions from the lung, gastrointestinal tract, liver but also the pancreas. Cystic Fibrosis-Related Diabetes (CFRD), the most common complication of CF, has a major detrimental impact on pulmonary function, nutrition and survival. Glucose derangements in CF seem to start from early infancy and, even when the pathophysiology is multifactorial, insulin insufficiency is clearly a major component. Consistently, recent evidence confirms that CFTR is an important regulator of insulin secretion by islet beta-cells. In addition, several other mechanisms were also recognized from cellular and animals models also contributing to either beta-cell mass reduction or beta-cell malfunction. Understanding such mechanisms is crucial to the development of the so-called "transformational" therapies in CF, including the preservation of insulin secretion. Innovative therapeutic approaches aim to modify specific CFTR mutant proteins or positively modulate their function. CFTR modulators recently showed in vitro capacity to enhance insulin secretion and thereby potential clinical utility in CFDR, including synergistic effects between corrector and potentiator drugs. The introduction of incretins and the optimization of exocrine pancreatic replacement complete the number of therapeutic options of CFRD besides early diagnosis and implementation of insulin therapy. This review focuses on the recently identified pathogenic mechanisms leading to CFRD relevant for the development of novel pharmacological avenues in CFRD therapy.
- Cell Wall Stress Activates Expression of a Novel Stress Response Facilitator (SrfA) Under σ22 (AlgT/U) Control in Pseudomonas aeruginosa. [JOURNAL ARTICLE]
- Microbiology 2014 Oct 21.
The ECF alternative sigma factor, sigma-22 (AlgT/U), is required for expression of the algD promoter of the operon for alginate biosynthesis in Pseudomonas aeruginosa. Alginate production promotes chronic pulmonary infections by this opportunistic pathogen in patients with cystic fibrosis and COPD. Sigma-22 is normally sequestered, but its de-regulation and activation occurs either by mutation in mucA (encoding an anti-sigma factor) or in response to envelope stress, such as inhibition of peptidoglycan synthesis. The sigma-22 stress response system includes many genes in addition to those for alginate. In the present study, we characterized an intergenic region between the open reading frames PA2559 and PA2560 in PAO1 for a sigma-22 dependent, stress responsive transcript, described here as PA2559.1. Northern analysis and transcript end mapping indicated the PA2559.1 transcript was approximately 310 nt in length. Examination of the DNA sequence upstream of +1 revealed a sigma-22 core promoter motif, GAATTT-N16-TCTGT, and site directed mutagenesis confirmed this to be a sigma-22 dependent promoter that is highly activated during cell wall stress. PA2559.1 also contained an open reading frame that demonstrated increased translational activity upon cell wall stress. As determined by mutant analysis, the PA2559.1 encoding protein was shown to play a positive role in the sigma-22 dependent activation of the algD promoter under stress in both sessile (i.e., biofilm) and planktonic conditions. Thus, it appears to act as a stress response facilitator, and so was named SrfA. The sequence of SrfA was found to be novel in nature and extremely well conserved only in P. aeruginosa, suggesting that it is of high evolutionary importance in this species.
- Detection of CFTR mutations using PCR/ARMS in a sample of Algerian population. [Journal Article]
- Ann Biol Clin (Paris) 2014 Oct 1; 72(5):549-54.
Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians. Wrongly considered as a European disease, CF is found in Algeria; but the literature data on the clinical profile and the spectrum of CFTR gene mutations are poor. In this study we investigate twenty-four unrelated Algerian families, with at least one child with CF. DNA extracts from blood samples of patients and parents were screened for CFTR gene mutations using Elucigene CF30 Kit which is based on a PCR/ARMS technique. Only five different mutations were identified. On the 48 alleles studied, most common mutations were: c.1521_1523delCTT (F508del) 18.75%, c.579+1G>T (711+1G>T) 12.5%, c.1624G>T (G542X) 10.41%, c.3909C>G (N1303K) 4%, and c.1652G>A (G551D) 2%. The Elucigene CF30 kit highlights a portion of CFTR mutations in the Algerian population. It remains important for a first screening as it reveals the most common mutations. All this information is of interest for genetic testing and genetic counseling in Algeria and in European countries where immigration from the Maghreb is common.
- Sperm-Associated Antigen 6 (SPAG6) Deficiency and Defects in Ciliogenesis and Cilia Function: Polarity, Density, and Beat. [JOURNAL ARTICLE]
- PLoS One 2014; 9(10):e107271.
SPAG6, an axoneme central apparatus protein, is essential for function of ependymal cell cilia and sperm flagella. A significant number of Spag6-deficient mice die with hydrocephalus, and surviving males are sterile because of sperm motility defects. In further exploring the ciliary dysfunction in Spag6-null mice, we discovered that cilia beat frequency was significantly reduced in tracheal epithelial cells, and that the beat was not synchronized. There was also a significant reduction in cilia density in both brain ependymal and trachea epithelial cells, and cilia arrays were disorganized. The orientation of basal feet, which determines the direction of axoneme orientation, was apparently random in Spag6-deficient mice, and there were reduced numbers of basal feet, consistent with reduced cilia density. The polarized epithelial cell morphology and distribution of intracellular mucin, α-tubulin, and the planar cell polarity protein, Vangl2, were lost in Spag6-deficient tracheal epithelial cells. Polarized epithelial cell morphology and polarized distribution of α-tubulin in tracheal epithelial cells was observed in one-week old wild-type mice, but not in the Spag6-deficient mice of the same age. Thus, the cilia and polarity defects appear prior to 7 days post-partum. These findings suggest that SPAG6 not only regulates cilia/flagellar motility, but that in its absence, ciliogenesis, axoneme orientation, and tracheal epithelial cell polarity are altered.