Cystic Fibrosis

High Genomic Identity between Clinical and Environmental Strains of <em>Herbaspirillum frisingense</em> Suggests Pre-Adaptation to Different Hosts and Intrinsic Resistance to Multiple Drugs

Sat, 2021-11-27 06:00

Antibiotics (Basel). 2021 Nov 18;10(11):1409. doi: 10.3390/antibiotics10111409.

ABSTRACT

The genus Herbaspirillum is widely studied for its ability to associate with grasses and to perform biological nitrogen fixation. However, the bacteria of the Herbaspirillum genus have frequently been isolated from clinical samples. Understanding the genomic characteristics that allow these bacteria to switch environments and become able to colonize human hosts is essential for monitoring emerging pathogens and predicting outbreaks. In this work, we describe the sequencing, assembly, and annotation of the genome of H. frisingense AU14559 isolated from the sputum of patients with cystic fibrosis, and its comparison with the genomes of the uropathogenic strain VT-16-41 and the environmental strains GSF30, BH-1, IAC152, and SG826. The genes responsible for biological nitrogen fixation were absent from all strains except for GSF30. On the other hand, genes encoding virulence and host interaction factors were mostly shared with environmental strains. We also identified a large set of intrinsic antibiotic resistance genes that were shared across all strains. Unlike other strains, in addition to unique genomic islands, AU14559 has a mutation that renders the biosynthesis of rhamnose and its incorporation into the exopolysaccharide unfeasible. These data suggest that H. frisingense has characteristics that provide it with the metabolic diversity needed to infect and colonize human hosts.

PMID:34827347 | DOI:10.3390/antibiotics10111409

Categories: Literature Watch

Sub-Inhibitory Antibiotic Exposure and Virulence in <em>Pseudomonas aeruginosa</em>

Sat, 2021-11-27 06:00

Antibiotics (Basel). 2021 Nov 13;10(11):1393. doi: 10.3390/antibiotics10111393.

ABSTRACT

Pseudomonas aeruginosa is a prime opportunistic pathogen, one of the most important causes of hospital-acquired infections and the major cause of morbidity and mortality in cystic fibrosis lung infections. One reason for the bacterium's pathogenic success is the large array of virulence factors that it can employ. Another is its high degree of intrinsic and acquired resistance to antibiotics. In this review, we first summarise the current knowledge about the regulation of virulence factor expression and production. We then look at the impact of sub-MIC antibiotic exposure and find that the virulence-antibiotic interaction for P. aeruginosa is antibiotic-specific, multifaceted, and complex. Most studies undertaken to date have been in vitro assays in batch culture systems, involving short-term (<24 h) antibiotic exposure. Therefore, we discuss the importance of long-term, in vivo-mimicking models for future work, particularly highlighting the need to account for bacterial physiology, which by extension governs both virulence factor expression and antibiotic tolerance/resistance.

PMID:34827331 | DOI:10.3390/antibiotics10111393

Categories: Literature Watch

Nano- and Macroscale Imaging of Cholesterol Linoleate and Human Beta Defensin 2-Induced Changes in <em>Pseudomonas aeruginosa</em> Biofilms

Sat, 2021-11-27 06:00

Antibiotics (Basel). 2021 Oct 20;10(11):1279. doi: 10.3390/antibiotics10111279.

ABSTRACT

The biofilm production of Pseudomonas aeruginosa (PA) is central to establishing chronic infection in the airways in cystic fibrosis. Epithelial cells secrete an array of innate immune factors, including antimicrobial proteins and lipids, such as human beta defensin 2 (HBD2) and cholesteryl lineolate (CL), respectively, to combat colonization by pathogens. We have recently shown that HBD2 inhibits biofilm production by PA, possibly linked to interference with the transport of biofilm precursors. Considering that both HBD2 and CL are increased in airway fluids during infection, we hypothesized that CL synergizes with HBD2 in biofilm inhibition. CL was formulated in phospholipid-based liposomes (CL-PL). As measured by atomic force microscopy of single bacteria, CL-PL alone and in combination with HBD2 significantly increased bacterial surface roughness. Additionally, extracellular structures emanated from untreated bacterial cells, but not from cells treated with CL-PL and HBD2 alone and in combination. Crystal violet staining of the biofilm revealed that CL-PL combined with HBD2 effected a significant decrease of biofilm mass and increased the number of larger biofilm particles consistent with altered cohesion of formed biofilms. These data suggest that CL and HBD2 affect PA biofilm formation at the single cell and community-wide level and that the community-wide effects of CL are enhanced by HBD2. This research may inform future novel treatments for recalcitrant infections in the airways of CF patients.

PMID:34827217 | DOI:10.3390/antibiotics10111279

Categories: Literature Watch

Predictors of mortality in children with cystic fibrosis in India

Fri, 2021-11-26 06:00

Pediatr Pulmonol. 2021 Nov 26. doi: 10.1002/ppul.25766. Online ahead of print.

ABSTRACT

BACKGROUND: There is a lack of studies on cystic fibrosis (CF) outcomes in children from developing countries like India. Identifying risk factors for mortality may help identify the high-risk group and plan policy management of such patients. We aimed to determine the factors associated with mortality among Indian children with CF.

METHODS: In this retrospective study, we extracted demography, clinical features, laboratory and outcome data from medical records of children with CF. Bivariate and multivariate analysis was performed to identify variables associated with mortality.

RESULTS: We enrolled 178 children, and there were 32 (18.0%) deaths. Median (IQR) z-score for body mass index (BMI) at last follow up was -1.5 (-2.7, -0.2) and -2.5 (-4.0, -1.6), p-value 0.039, in survived and deceased group respectively. Mean (SD) of % predicted of FEV1/FVC and FEV1 25-75 at the time of diagnosis in survived versus diseased group was 94.7 (24.1) versus 81.5 (19.1), p-value 0.063 and 56.1 (38.9) versus 45.7 (29.9), p-value 0.347, respectively. Significant factors associated with mortality included history of neonatal complications; hazard ratio (HR): 8.5 (95% confidence interval [CI]: 3.0-23.9, p < 0.001), low Z-scores for BMI at the time of diagnosis; HR: 7.1 (95% CI: 2.3-22.0, p < 0.001), FEV1/FVC at the time of diagnosis; HR: 5.1 (95% CI: 1.65-15.4, p < 0.004), and FEV1 25-75; HR: 3.6 (95% CI: 1.1-11.8, p = 0.03).

CONCLUSIONS: Factors associated with increased mortality risk included neonatal complications, low BMI, and lower pulmonary function test results. Low BMI and low PFT indices can be improved upon by timely treatment of respiratory infections, better nutrition, early diagnosis, and treatment. A newborn screening program may help in early diagnosis and identification of the neonatal problem of CF.

PMID:34826368 | DOI:10.1002/ppul.25766

Categories: Literature Watch

Genome evolution drives transcriptomic and phenotypic adaptation in <em>Pseudomonas aeruginosa</em> during 20 years of infection

Fri, 2021-11-26 06:00

Microb Genom. 2021 Nov;7(11). doi: 10.1099/mgen.0.000681.

ABSTRACT

The opportunistic pathogen Pseudomonas aeruginosa chronically infects the lungs of patients with cystic fibrosis (CF). During infection the bacteria evolve and adapt to the lung environment. Here we use genomic, transcriptomic and phenotypic approaches to compare multiple isolates of P. aeruginosa collected more than 20 years apart during a chronic infection in a CF patient. Complete genome sequencing of the isolates, using short- and long-read technologies, showed that a genetic bottleneck occurred during infection and was followed by diversification of the bacteria. A 125 kb deletion, an 0.9 Mb inversion and hundreds of smaller mutations occurred during evolution of the bacteria in the lung, with an average rate of 17 mutations per year. Many of the mutated genes are associated with infection or antibiotic resistance. RNA sequencing was used to compare the transcriptomes of an earlier and a later isolate. Substantial reprogramming of the transcriptional network had occurred, affecting multiple genes that contribute to continuing infection. Changes included greatly reduced expression of flagellar machinery and increased expression of genes for nutrient acquisition and biofilm formation, as well as altered expression of a large number of genes of unknown function. Phenotypic studies showed that most later isolates had increased cell adherence and antibiotic resistance, reduced motility, and reduced production of pyoverdine (an iron-scavenging siderophore), consistent with genomic and transcriptomic data. The approach of integrating genomic, transcriptomic and phenotypic analyses reveals, and helps to explain, the plethora of changes that P. aeruginosa undergoes to enable it to adapt to the environment of the CF lung during a chronic infection.

PMID:34826267 | DOI:10.1099/mgen.0.000681

Categories: Literature Watch

A restructuring of microbiome niche space is associated with Elexacaftor-Tezacaftor-Ivacaftor therapy in the cystic fibrosis lung

Fri, 2021-11-26 06:00

J Cyst Fibros. 2021 Nov 22:S1569-1993(21)02131-7. doi: 10.1016/j.jcf.2021.11.003. Online ahead of print.

ABSTRACT

BACKGROUND: Elexacaftor-Tezacaftor-Ivacaftor (ETI) therapy is showing promising efficacy for treatment of cystic fibrosis (CF) and is becoming more widely available since recent FDA approval. However, little is known about how these drugs will affect lung infections, which are the leading cause of morbidity and mortality among people with CF (pwCF).

METHODS: We analyzed sputum microbiome and metabolome data from pwCF (n=24) before and after ETI therapy using 16S rRNA gene sequencing and untargeted metabolomics.

RESULTS: The sputum microbiome diversity, particularly its evenness, was increased (p=0.036) and the microbiome profiles were different between individuals before and after therapy (PERMANOVA F=1.92, p=0.044). Despite these changes, the microbiomes remained more similar within an individual than across the sampled population. No specific microbial taxa differed in relative abundance before and after therapy, but the collective log-ratio of classic CF pathogens to anaerobes significantly decreased (p=0.013). The sputum metabolome also showed changes associated with ETI (PERMANOVA F=4.22, p=0.002) and was characterized by greater variation across subjects while on treatment. Changes in the metabolome were driven by a decrease in peptides, amino acids, and metabolites from the kynurenine pathway, which were associated with a decrease in CF pathogens. Metabolism of the three small molecules that make up ETI was extensive, including previously uncharacterized structural modifications.

CONCLUSIONS: ETI therapy is associated with a changing microbiome and metabolome in airway mucus. This effect was stronger on sputum biochemistry, which may reflect changing niche space for microbial residency in lung mucus as the drug's effects take hold.

FUNDING: This project was funded by a National Institute of Allergy and Infectious Disease Grant R01AI145925.

PMID:34824018 | DOI:10.1016/j.jcf.2021.11.003

Categories: Literature Watch

Mucus threads from surface goblet cells clear particles from the airways

Fri, 2021-11-26 06:00

Respir Res. 2021 Nov 25;22(1):303. doi: 10.1186/s12931-021-01898-3.

ABSTRACT

BACKGROUND: The mucociliary clearance system driven by beating cilia protects the airways from inhaled microbes and particles. Large particles are cleared by mucus bundles made in submucosal glands by parallel linear polymers of the MUC5B mucins. However, the structural organization and function of the mucus generated in surface goblet cells are poorly understood.

METHODS: The origin and characteristics of different mucus structures were studied on live tissue explants from newborn wild-type (WT), cystic fibrosis transmembrane conductance regulator (CFTR) deficient (CF) piglets and weaned pig airways using video microscopy, Airyscan imaging and electron microscopy. Bronchoscopy was performed in juvenile pigs in vivo.

RESULTS: We have identified a distinct mucus formation secreted from the surface goblet cells with a diameter less than two micrometer. This type of mucus was named mucus threads. With time mucus threads gathered into larger mucus assemblies, efficiently collecting particles. The previously observed Alcian blue stained mucus bundles were around 10 times thicker than the threads. Together the mucus bundles, mucus assemblies and mucus threads cleared the pig trachea from particles.

CONCLUSIONS: These results demonstrate that normal airway mucus is more complex and has a more variable structural organization and function than was previously understood. These observations emphasize the importance of studying young objects to understand the function of a non-compromised lung.

PMID:34823518 | DOI:10.1186/s12931-021-01898-3

Categories: Literature Watch

The Mitochondrial Ca<sup>2+</sup> import complex is altered in ADPKD

Thu, 2021-11-25 06:00

Cell Calcium. 2021 Nov 19;101:102501. doi: 10.1016/j.ceca.2021.102501. Online ahead of print.

ABSTRACT

Mutations in either of the polycystic kidney disease genes, PKD1 or PKD2, engender the growth of cysts, altering renal function. Cystic growth is supported by major changes in cellular metabolism, some of which involve the mitochondrion, a major storage site for Ca2+ and a key organelle in cellular Ca2+ signaling. The goal here was to understand the role of components of the mitochondrial Ca2+ uptake complex in PC1-mutant cells in autosomal dominant polycystic kidney disease (ADPKD). We found that the mitochondrial Ca2+ uniporter (MCU) and voltage-dependent anion channels 1& 3 (VDAC) were down-regulated in different mouse and cell models of ADPKD along with the Ca2+-dependent enzyme, pyruvate dehydrogenase phosphatase (PDHX). The release of Ca2+ from the endoplasmic reticulum, and Ca2+ uptake by the mitochondria were upregulated in PC1(polycystin)-null cells. We also observed an enhanced staining with MitoTracker Red CMXRos in PC1-null cultured cells than in PC1-containing cells and a substantially higher increase in response to ER Ca2+ release. Increased colocalization of the Ca2+ sensitive dye, rhodamine2, with MitoTracker Green suggested an increase Ca2+ entry into the mitochondria in PC1 null cells subsequent to Ca2+ release from the ER or from Ca2+ entry from the extracellular solution. These data clearly demonstrate abnormal release of Ca2+ by the ER and corresponding alterations in Ca2+ uptake by the mitochondria in PC1-null cells. Importantly, inhibiting mitochondrial Ca2+ uptake with the specific inhibitor Ru360 inhibited cyst growth and altered both apoptosis and cell proliferation. We further show that the decrease in mitochondrial proteins and abnormally high Ca2+ signaling can be reversed by application of the cystic fibrosis (CFTR) corrector, VX-809. We conclude that enhanced Ca2+ signaling and alterations in proteins association with the mitochondrial Ca2+ uptake complex are associated with malfunction of PC1. Finally, our results identify novel therapeutic targets for treating ADPKD.

PMID:34823104 | DOI:10.1016/j.ceca.2021.102501

Categories: Literature Watch

Differentiation of Cystic Fibrosis-Related Pathogens by Volatile Organic Compound Analysis with Secondary Electrospray Ionization Mass Spectrometry

Thu, 2021-11-25 06:00

Metabolites. 2021 Nov 11;11(11):773. doi: 10.3390/metabo11110773.

ABSTRACT

Identifying and differentiating bacteria based on their emitted volatile organic compounds (VOCs) opens vast opportunities for rapid diagnostics. Secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS) is an ideal technique for VOC-biomarker discovery because of its speed, sensitivity towards polar molecules and compound characterization possibilities. Here, an in vitro SESI-HRMS workflow to find biomarkers for cystic fibrosis (CF)-related pathogens P. aeruginosa, S. pneumoniae, S. aureus, H. influenzae, E. coli and S. maltophilia is described. From 180 headspace samples, the six pathogens are distinguishable in the first three principal components and predictive analysis with a support vector machine algorithm using leave-one-out cross-validation exhibited perfect accuracy scores for the differentiation between the groups. Additionally, 94 distinctive features were found by recursive feature elimination and further characterized by SESI-MS/MS, which yielded 33 putatively identified biomarkers. In conclusion, the six pathogens can be distinguished in vitro based on their VOC profiles as well as the herein reported putative biomarkers. In the future, these putative biomarkers might be helpful for pathogen detection in vivo based on breath samples from patients with CF.

PMID:34822431 | DOI:10.3390/metabo11110773

Categories: Literature Watch

SLC26A9 is selected for endoplasmic reticulum associated degradation (ERAD) via Hsp70-dependent targeting of the soluble STAS domain

Thu, 2021-11-25 06:00

Biochem J. 2021 Nov 25:BCJ20210644. doi: 10.1042/BCJ20210644. Online ahead of print.

ABSTRACT

SLC26A9, a member of the solute carrier protein family, transports chloride ions across various epithelia. SLC26A9 also associates with other ion channels and transporters linked to human health, and in some cases these heterotypic interactions are essential to support the biogenesis of both proteins. Therefore, understanding how this complex membrane protein is initially folded might provide new therapeutic strategies to overcome deficits in the function of SLC26A9 partners, one of which is associated with Cystic Fibrosis. To this end, we developed a novel yeast expression system for SLC26A9. This facile system has been used extensively with other ion channels and transporters to screen for factors that oversee protein folding checkpoints. As commonly observed for other channels and transporters, we first noted that a substantial fraction of SLC26A9 is targeted for endoplasmic reticulum associated degradation (ERAD), which destroys folding-compromised proteins in the early secretory pathway. We next discovered that ERAD selection requires the Hsp70 chaperone, which can play a vital role in ERAD substrate selection. We then created SLC26A9 mutants and found that the transmembrane-rich domain of SLC26A9 was quite stable, whereas the soluble cytosolic STAS domain was responsible for Hsp70-dependent ERAD. To support data obtained in the yeast model, we were able to recapitulate Hsp70-facilitated ERAD of the STAS domain in human tissue culture cells. These results indicate that a critical barrier to nascent membrane protein folding can reside within a specific soluble domain, one that is monitored by components associated with the ERAD machinery.

PMID:34821356 | DOI:10.1042/BCJ20210644

Categories: Literature Watch

Consideration of height-based tobramycin dosing regimens for the treatment of adult cystic fibrosis pulmonary exacerbations

Thu, 2021-11-25 06:00

Br J Clin Pharmacol. 2021 Nov 24. doi: 10.1111/bcp.15154. Online ahead of print.

ABSTRACT

AIM: Some population pharmacokinetic models have been developed using height to explain some of the interindividual variability in tobramycin pharmacokinetics in cystic fibrosis patients. However, their predictive performance when extrapolated to other clinical centers is unclear. Therefore, the aim for this study was to externally evaluate the predictability of tobramycin population pharmacokinetic models with an independent dataset and perform simulations using previously recommended height-based dosing regimens.

METHODS: A literature search was conducted through the PubMed database to identify relevant population pharmacokinetic models. Tobramycin plasma concentration data from April 2014 to November 2019 were retrospectively collected from the Institut universitaire de cardiologie et de pneumologie de Québec, Canada. External evaluations were performed using NONMEM®️ v7.5 and RStudio®️ v1.3.1073. Monte Carlo simulations were performed to evaluate the probability of target attainment of Cmax /MIC ratios for several dosing regimens.

RESULTS: The validation dataset included 27 patients and 143 concentration samples. Three models were evaluated. Only the ones by Crass et al. and Alghanem et al. performed satisfactorily in terms of prediction-based diagnostics with MDPE and MDAPE values of -3.4% and 29.3% & 19.0 and 29.5%, respectively. In simulation-based evaluations, both pcVPC and NPDE showed no evidence of model misspecification. Our simulations suggest that patients treated with a once-daily dose of 3.4 mg/cm should produce peak and trough levels consistent with current guidelines.

CONCLUSION: Our results show that the models by Crass et al. and Alghanem et al. are appropriate for simulation-based applications to aid individualized dosing in our population and that height-based dosing regimens could be considered in cystic fibrosis patients.

PMID:34820875 | DOI:10.1111/bcp.15154

Categories: Literature Watch

ROSE: radiology, obstruction, symptoms and exposure - a Delphi consensus definition of the association of COPD and bronchiectasis by the EMBARC Airways Working Group

Thu, 2021-11-25 06:00

ERJ Open Res. 2021 Nov 22;7(4):00399-2021. doi: 10.1183/23120541.00399-2021. eCollection 2021 Oct.

ABSTRACT

INTRODUCTION: The coexistence of COPD and bronchiectasis seems to be common and associated with a worse prognosis than for either disease individually. However, no definition of this association exists to guide researchers and clinicians.

METHODS: We conducted a Delphi survey involving expert pulmonologists and radiologists from Europe, Turkey and Israel in order to define the "COPD- [bronchiectasis] BE association".A panel of 16 experts from EMBARC selected 35 statements for the survey after reviewing scientific literature. Invited participants, selected on the basis of expertise, geographical and sex distribution, were asked to express agreement on the statements. Consensus was defined as a score of ≥6 points (scale 0 to 9) in ≥70% of answers across two scoring rounds.

RESULTS: 102 (72.3%) out of 141 invited experts participated in the first round. Their response rate in the second round was 81%. The final consensus definition of "COPD-BE association" was: "The coexistence of (1) specific radiological findings (abnormal bronchial dilatation, airways visible within 1 cm of pleura and/or lack of tapering sign in ≥1 pulmonary segment and in >1 lobe) with (2) an obstructive pattern on spirometry ([forced expiratory volume in 1 s] FEV1/[forced vital capacity] FVC <0.7), (3) at least two characteristic symptoms (cough, expectoration, dyspnoea, fatigue, frequent infections) and (4) current or past exposure to smoke (10 pack-years) or other toxic agents (biomass, etc.)". These criteria form the acronym "ROSE" (Radiology, Obstruction, Symptoms, Exposure).

CONCLUSIONS: The Delphi process formulated a European consensus definition of "COPD-BE association". We hope this definition will have broad applicability across clinical practice and research in the future.

PMID:34820447 | PMC:PMC8607072 | DOI:10.1183/23120541.00399-2021

Categories: Literature Watch

Role of Non-Coding RNAs in Post-Transcriptional Regulation of Lung Diseases

Thu, 2021-11-25 06:00

Front Genet. 2021 Nov 8;12:767348. doi: 10.3389/fgene.2021.767348. eCollection 2021.

ABSTRACT

Non-coding RNAs (ncRNAs), notably microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), have recently gained increasing consideration because of their versatile role as key regulators of gene expression. They adopt diverse mechanisms to regulate transcription and translation, and thereby, the function of the protein, which is associated with several major biological processes. For example, proliferation, differentiation, apoptosis, and metabolic pathways demand fine-tuning for the precise development of a specific tissue or organ. The deregulation of ncRNA expression is concomitant with multiple diseases, including lung diseases. This review highlights recent advances in the post-transcriptional regulation of miRNAs and lncRNAs in lung diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. Further, we also discuss the emerging role of ncRNAs as biomarkers as well as therapeutic targets for lung diseases. However, more investigations are required to explore miRNAs and lncRNAs interaction, and their function in the regulation of mRNA expression. Understanding these mechanisms might lead to early diagnosis and the development of novel therapeutics for lung diseases.

PMID:34819948 | PMC:PMC8606426 | DOI:10.3389/fgene.2021.767348

Categories: Literature Watch

Physiotherapy approach after lung transplantation in a critically ill COVID-19 patient: a case report

Thu, 2021-11-25 06:00

Monaldi Arch Chest Dis. 2021 Nov 24. doi: 10.4081/monaldi.2021.2004. Online ahead of print.

ABSTRACT

This study describes the case of an 18-years-old male affected by severe COVID-19, who was receiving bilateral lung transplantation (LT), after 71 days of mechanical ventilation and 55 days of veno-venous extracorporeal membrane oxygenation. From post-operative day 2, early mobilization and physiotherapy treatments were performed. Weaning from mechanical ventilation, the use of non-invasive ventilation and tracheostomy management were included in the treatment. Forty-five days after LT the patient was discharged at home, showing improvements in terms of functional and respiratory parameters, quality of life and mood. While evidences about physiotherapy treatments in lung transplantation post severe COVID-19 remain limited, early approach and a multidisciplinary team may be considered key elements for functional recovery of these subjects.

PMID:34818884 | DOI:10.4081/monaldi.2021.2004

Categories: Literature Watch

A novel smaller β-defensin-derived peptide is active against multidrug-resistant bacterial strains

Wed, 2021-11-24 06:00

FASEB J. 2021 Dec;35(12):e22026. doi: 10.1096/fj.202002330RR.

ABSTRACT

Antibiotic resistance is becoming a severe obstacle in the fight against acute and chronic infectious diseases that accompany most degenerative illnesses from neoplasia to osteo-arthritis and obesity. Currently, the race is on to identify pharmaceutical molecules or combinations of molecules able to prevent or reduce the insurgence and/or progression of infectivity. Attempts to substitute antibiotics with antimicrobial peptides have, thus far, met with little success against multidrug-resistant (MDR) bacterial strains. During the last decade, we designed and studied the activity and features of human β-defensin analogs, which are salt-resistant, and hence active also under high salt concentrations as, for instance, in cystic fibrosis. Herein, we describe the design, synthesis, and major features of a new 21 aa long molecule, peptide γ2. The latter derives from the γ-core of the β-defensin natural molecules, a small fragment of these molecules still bearing high antibacterial activity. We found that peptide γ2, which contains only one disulphide bond, recapitulates most of the biological properties of natural human β-defensins and can also counteract both Gram-positive and Gram-negative MDR bacterial strains and biofilm formation. Moreover, it has great stability in human serum thereby enhancing its antibacterial presence and activity without cytotoxicity in human cells. In conclusion, peptide γ2 is a promising new weapon also in the battle against intractable infectious diseases.

PMID:34818435 | DOI:10.1096/fj.202002330RR

Categories: Literature Watch

Optimising the care and quality of life of people with cystic fibrosis: the influence of cystic fibrosis transmembrane conductance regulator modulators

Wed, 2021-11-24 06:00

Br J Hosp Med (Lond). 2021 Nov 2;82(11):1-6. doi: 10.12968/hmed.2021.0530. Epub 2021 Nov 22.

ABSTRACT

Cystic fibrosis is a life-limiting, inherited, multi-organ disease which affects many systems of the body. Until recently, treatments were only able to ameliorate symptoms, but the introduction of precision medications which modulate the underlying defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene has changed this. Notably improvements in nutrition and lung function, reduced use of antibiotics and reduced occupation rates for hospital beds have been seen. This article summarises the discussion of a group of healthcare professionals from different specialties and an expert patient, representing their personal views and experience of treating patients who are using CFTR modulators. The discussion was sponsored by an unrestricted grant from Chiesi Limited (Manchester, UK).

PMID:34817261 | DOI:10.12968/hmed.2021.0530

Categories: Literature Watch

Age- and sex-specific pediatric reference intervals for neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and platelet-to-lymphocyte ratio

Wed, 2021-11-24 06:00

Int J Lab Hematol. 2021 Nov 23. doi: 10.1111/ijlh.13768. Online ahead of print.

ABSTRACT

INTRODUCTION: Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) are emerging biomarkers for systemic inflammation and have been shown to predict morbidity and mortality for several diseases. However, lack of pediatric reference intervals (RIs) prevents their comprehensive use in patient care and medical research.

MATERIAL AND METHODS: We calculated reference intervals and corresponding confidence intervals for NLR, PLR, and LMR from birth to 18 years using a data-mining approach: We analyzed 232 746 blood counts from 60 685 patients performed during patient care and excluded patients with elevated C-reactive protein and procalcitonin. Test results were separated according to age and sex, and the distribution of physiological ratios was estimated using an indirect approach (refineR). Additionally, we investigated the ratios' diagnostic benefit for different inflammatory diseases (acute appendicitis, asthma, Bell's palsy, Henoch-Schonlein purpura, and cystic fibrosis) using the newly obtained reference intervals.

RESULTS: We estimated age- and sex-specific reference intervals from birth to adulthood for NLR, PLR, and LMR. Analyses in pediatric inflammatory diseases showed that PLR and LMR were poor markers to detect the examined inflammatory diseases, while NLR was significantly increased in patients with appendicitis and asthma.

CONCLUSION: We provide pediatric reference intervals for NLR, PLR, and LMR to improve the interpretation of these biomarkers in children.

PMID:34816610 | DOI:10.1111/ijlh.13768

Categories: Literature Watch

The adverse association between stimulant use for attention deficit hyperactivity disorder (ADHD) and semen parameters

Wed, 2021-11-24 06:00

Andrologia. 2021 Nov 23:e14315. doi: 10.1111/and.14315. Online ahead of print.

ABSTRACT

This study examined the relationship between stimulant medications used for the treatment of attention deficit hyperactivity disorder and semen parameters. We performed a retrospective cohort study at a large, academic institution between 2002 and 2020. We included men with a semen analysis without prior spermatotoxic medication use, empiric medical therapy exposure or confounding medical diagnoses (varicocele, Klinefelter's syndrome, cryptorchidism, cystic fibrosis, diabetes, cancer or cancer-related treatment, and azoospermia). Men were stratified by stimulant exposure (methylphenidate or amphetamines). A multivariable linear regression was fit to assess the association between individual semen parameters, age, stimulant exposure and non-stimulant medication use. Of 8,861 men identified, 106 men had active prescriptions for stimulants within 90 days prior to semen testing. After controlling for age and exposure to non-stimulant medications, stimulant use was associated with decreased total motile sperm count (β: -18.00 mil/ejaculate and standard error: 8.44, p = 0.033) in the setting of decreased semen volume (β: -0.35 ml, and standard error: 0.16, p = 0.035), but not sperm concentration, motility and morphology. These findings suggest a role for reproductive physicians and mental health providers to consider counselling men on the potential negative impact of stimulants prescribed for attention deficit hyperactivity disorder on semen volume during fertility planning.

PMID:34816465 | DOI:10.1111/and.14315

Categories: Literature Watch

Antimicrobial properties of phytohormone (gibberellins) against phytopathogens and clinical pathogens

Wed, 2021-11-24 06:00

Access Microbiol. 2021 Oct 20;3(10):000278. doi: 10.1099/acmi.0.000278. eCollection 2021.

ABSTRACT

The in vitro antimicrobial potential of physiologically active diterpenoid plant-derived gibberellins (gibberellic acids; GAs) was tested on microbial pathogens of significance to plant and human health. The racemic enantiomer GA3 produced varying inhibitory effects against a wide range of plant host disease causal agents (phytopathogens) comprising fungi, oomycetes and bacteria. The results showed that GA3 effected either strong growth arrest of phytopathogenic fungi or holistic biocidal effects on oomycete and phytopathogenic fungi at higher concentration (>10-50 mM) and increased hyphal extension growth when the concentration of GA3 was lowered (<10-0.1 mM). When human clinical pathogenic bacteria cohorts were challenged with gibberellin enantiomers, viz GA1, GA4, GA5, GA7, GA9 and GA13 (50 mM), employing Kirby-Bauer disc bioassay methods for assessment of their efficacies, no inhibitory effect was seen with gibberellin enantiomers, viz GA1, GA3, GA5 and GA13, while GA4 inhibited all human clinical bacterial organisms examined, with GA7 and GA9 showing limited activity. The antibiotic effects of enantiomeric diterpenoid phytohormones evinced in our preliminary study raise prospects for further studies to fully examine their potential therapeutic value for human healthcare and their compliance with cytotoxicity and other ethical considerations in the future.

PMID:34816094 | PMC:PMC8604178 | DOI:10.1099/acmi.0.000278

Categories: Literature Watch

A Clinician's guide to vitamin D supplementation for patients with cystic fibrosis

Wed, 2021-11-24 06:00

J Clin Transl Endocrinol. 2021 Nov 6;26:100273. doi: 10.1016/j.jcte.2021.100273. eCollection 2021 Dec.

ABSTRACT

Vitamin D deficiency is common in the general population, and even more so in patients with cystic fibrosis. Deficiency is exacerbated in cystic fibrosis patients because of a myriad of causes including malabsorption, decreased fat mass, reduced 25-hydroxylation of vitamin D, reduced exposure to sunlight, decreased vitamin D binding protein, and exposure to drugs that increase catabolism. In turn, vitamin D deficiency can contribute to poor bone health. Additionally, it may contribute to pulmonary decline in the form of worsening pulmonary function, increased colonization with pathogens, and increased pulmonary exacerbation. Because vitamin D deficiency is correlated with negative clinical effects in multiple organ systems of patients with cystic fibrosis, it is important to screen for and treat deficiency in these patients. The Cystic Fibrosis Foundation has issued guidelines for the treatment of vitamin D deficiency, targeting serum levels of 25-hydroxyvitamin D of at least 30 ng/ml. The guidelines offer age-specific escalating dose regimens depending on serum vitamin D levels, with monitoring at 12- week intervals after changing therapy. They address the literature on alternative vitamin D sources, such as UV lamps, ideal formulations (cholecalciferol in preference to ergocalciferol), and optimal vehicles of administration. Despite these detailed recommendations, most centers are still unable to achieve in-target serum vitamin D levels for many of their patients. Future research examining ideal treatment regimens to achieve serum targets and maximize clinical effects are needed. Moreover, it is unknown whether vitamin D sufficiency will be easier to achieve on new triple therapy cystic fibrosis drug combinations, and how these drugs will contribute to vitamin D-related clinical outcomes.

PMID:34815946 | PMC:PMC8593649 | DOI:10.1016/j.jcte.2021.100273

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