Phase Ib trial of inhaled iloprost for the prevention of lung cancer with predictive and response biomarker assessment.

Introduction: Iloprost, a prostacyclin analog, has lung cancerpreventive activity in preclinical models and improved dysplasia in former smokers in a phase IIb trial. Oral iloprost is currently unavailable. We performed a phase Ib trial of inhaled iloprost in former smokers to assess tolerance and compliance. Methods: Participants self-administered nebulized iloprost (5ug) or placebo four (QID) or two (BID) times daily. As QID dose was well tolerated and due to expiration of the placebo, the BID dosing and placebo were eliminated early on in the trial. Bronchoscopy with biopsyat six standard sites was performed at treatment initiation and two months post-iloprost, with exploratory histological analysis. Bulk RNA sequencing, single cell RNA sequencing and an in vitro assay of epithelial progenitor cell iloprost response were performed on a subset of biopsies in an exploratory investigation of response mechanisms and predictive biomarkers. Results and discussion: Thirty-four of a planned 48 participants were recruited to the trial.Inhaled iloprost was well tolerated with no adverse events > grade 2. Compliance was 67% in the QID group. The trial was not powered to detect histologic response and none was found. Bulk RNA sequencing of biopsies pre/post iloprost suggest that iloprost is immunomodulatory and downregulates cell proliferation pathways. Single cell RNA sequencing showed an increase in CD8-positive T cells with upregulation of genes in interferon γ signaling. In vitro iloprost response by epithelial progenitor cells correlated with histologic response with kappa coefficient of 0.81 (95% CI 0.47, 1.0). Inhaled iloprost was well tolerated with suboptimal compliance. Molecular analysis suggested that iloprosthas immunomodulatory and antiproliferative effects.The progenitor cell iloprost response assay may be a promising avenue to develop predictive biomarkers. Clinical trial registration: https://clinicaltrials.gov/study/NCT02237183, identifier NCT02237183.

Mutation of putative glycosyl transferases PslC and PslI confers susceptibility to antibiotics and leads to drastic reduction in biofilm formation in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic, multidrug-resistant pathogen capable of adapting to numerous environmental conditions and causing fatal infections in immunocompromised patients. The predominant lifestyle of P. aeruginosa is in the form of biofilms, which are structured communities of bacteria encapsulated in a matrix containing exopolysaccharides, extracellular DNA (eDNA) and proteins. The matrix is impervious to antibiotics, rendering the bacteria tolerant to antimicrobials. P. aeruginosa also produces a plethora of virulence factors such as pyocyanin, rhamnolipids and lipopolysaccharides among others. In this study we present the molecular characterization of pslC and pslI genes, of the exopolysaccharide operon, that code for putative glycosyltransferases. PslC is a 303 amino acid containing putative GT2 glycosyltrasferase, whereas PslI is a 367 aa long protein, possibly functioning as a GT4 glycosyltransferase. Mutation in either of these two genes results in a significant reduction in biofilm biomass with concomitant decline in c-di-GMP levels in the bacterial cells. Moreover, mutation in pslC and pslI dramatically increased susceptibility of P. aeruginosa to tobramycin, colistin and ciprofloxacin. Additionally, these mutations also resulted in an increase in rhamnolipids and pyocyanin formation. We demonstrate that elevated rhamnolipids promote a swarming phenotype in the mutant strains. Together these results highlight the importance of PslC and PslI in the biogenesis of biofilms and their potential as targets for increased antibiotic susceptibility and biofilm inhibition.

Structural analysis of novel drug targets for mitigation of Pseudomonas aeruginosa biofilms.

Pseudomonas aeruginosa is an opportunistic human pathogen responsible for acute and chronic, hard to treat infections. Persistence of P. aeruginosa is due to its ability to develop into biofilms, which are sessile bacterial communities adhered to substratum and encapsulated in layers of self-produced exopolysaccharides. These biofilms provide enhanced protection from the host immune system and resilience towards antibiotics, which poses a challenge for treatment. Various strategies have been expended for combating biofilms, which involve inhibiting biofilm formation or promoting their dispersal. The current remediation approaches offer some hope for clinical usage, however, treatment and eradication of preformed biofilms is still a challenge. Thus, identifying novel targets and understanding the detailed mechanism of biofilm regulation becomes imperative. Structure-based drug discovery (SBDD) provides a powerful tool that exploits the knowledge of atomic resolution details of the targets to search for high affinity ligands. This review describes the available structural information on the putative target protein structures that can be utilized for high throughput in silico drug discovery against P. aeruginosa biofilms. Integrating available structural information on the target proteins in readily accessible format will accelerate the process of drug discovery.

Inhibition and eradication of Pseudomonas aeruginosa biofilms by secondary metabolites of Nocardiopsis lucentensis EMB25.

Millions of people worldwide have been impacted by biofilm-associated disorders, which are impregnable owing to frequent changes in surface antigens and gene expression. Globally, about 11% of nosocomial infections, including cystic fibrosis, chronic wound infections, and post-surgical infections, are caused by Pseudomonas aeruginosa, the most prevalent Gram-negative bacterial species. Moreover, biofilms are highly resistant to the host's immune system, and exhibit increased tolerance to stress factors such as starvation, dehydration, and antimicrobials. Here, we have isolated a rare halophilic actinobacteria, Nocardiopsis lucentensis EMB25, and utilized the secondary metabolites for inhibition and eradication of P. aeruginosa biofilm. For the first time, N. lucentensis EMB25 bacteria was explored to study the anti-effect of secondary metabolites on pre-established biofilm. The secondary metabolites targeted the quorum sensing pathway and were found to bind to LasR and RhlR, as confirmed via molecular docking. Also, the reduction in virulence factors, rhamnolipids and pyocyanin further supported the study as these two are regulated by LasR and RhlR. In addition, the downregulation of various QS system genes lasA, lasB, rhlA, rhlB, and pqsA confirmed that the secondary metabolites act on two main regulators of the quorum sensing pathway, LasR, and RhlR. The findings of this study support the bioprospecting of previously unknown and extreme-condition actinobacteria as a rich source of novel bioactives against infections caused by bacterial biofilms.

Lung adenocarcinoma promotion by air pollutants.

A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development1. Here we propose that environmental particulate matter measuring ≤2.5 µm (PM2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue. Focusing on EGFR-driven lung cancer, which is more common in never-smokers or light smokers, we found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases in four within-country cohorts. Functional mouse models revealed that air pollutants cause an influx of macrophages into the lung and release of interleukin-1ß. This process results in a progenitor-like cell state within EGFR mutant lung alveolar type II epithelial cells that fuels tumorigenesis. Ultradeep mutational profiling of histologically normal lung tissue from 295 individuals across 3 clinical cohorts revealed oncogenic EGFR and KRAS driver mutations in 18% and 53% of healthy tissue samples, respectively. These findings collectively support a tumour-promoting role for  PM2.5 air pollutants  and provide impetus for public health policy initiatives to address air pollution to reduce disease burden.

Assessment of myocardial function in late preterm and term infants with transient tachypnea of the newborn using tissue Doppler imaging - a pilot observational study.

The aim of this study was to compare conventional and tissue Doppler echocardiography parameters between transient tachypnea of the newborn (TTN) and healthy control infants. This cross sectional pilot observational study was conducted in a level 3 neonatal care unit of India. Consecutively born late preterm and term infants (LPTI) with TTN were eligible for enrollment. Control group was selected from healthy LPTI. Conventional and tissue Doppler (myocardial velocities, myocardial performance index (MPI)) echocardiography was done within first 12 h (D1) and 48-72 h (D3) of life. Conventional echocardiography parameters were fractional shortening (FS), ejection fraction (EF), ventricular output, E/A ratio, fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP), and pulmonary artery acceleration to ejection time ratio (PATET). Baseline characteristics and echocardiography images were compared between TTN and control groups. Out of 60 infants enrolled, 34 from TTN and 20 from control group were finally analyzed. Mean (SD) gestational age and birth weight of the study population was 366/7(1.8) weeks and 2398(376) g respectively. Left ventricular (LV) parameters were similar between both groups. On D1, right ventricular (RV)e' was smaller (6.42(1) cm/s vs. 7.68(1.68) cm/s, p 0.022), and E/e' (7.79(1.51) vs. 6.08(2.59), p 0.037) was larger in TTN group, indicating RV diastolic dysfunction. RV MPI (0.61(0.11) vs. 0.44(0.12), p < 0.001) was also larger, signifying RV global myocardial dysfunction. Similar findings were observed on D3. PATET was lower in TTN group on both D1 (0.34 (0.05) vs. 0.42 (0.05), p < 0.001) and D3 (0.38 (0.05) vs. 0.43 (0.02), p 0.004) suggesting persistently raised pulmonary arterial pressure, although only 2 infants developed pulmonary hypertension identified by standard echocardiography.   Conclusion: Myocardial tissue Doppler imaging of TTN infants revealed occult right ventricular diastolic dysfunction secondary to persistently raised pulmonary arterial pressure. What is Known: •Transient tachypnea of the newborn may be associated with pulmonary arterial hypertension. What is New: •Tissue Doppler imaging in infants with transient tachypnea of the newborn revealed occult right ventricular diastolic dysfunction secondary to raised pulmonary arterial pressure, not detected by standard echocardiography.

Prediction of surfactant requirement in Indian preterm infants by lung ultrasound scores: a diagnostic accuracy study from a developing country.

The purpose of this study is to validate lung ultrasound score (LUS) for prediction of surfactant replacement therapy (SRT) in Indian infants of 27-336/7 weeks gestational age (GA). This prospective diagnostic accuracy study was conducted in a level 3 neonatal care unit in India. Consecutively born preterm infants with respiratory distress syndrome (RDS) were enrolled. Surfactant was administered if oxygen requirement exceeded > 30%. Baseline characteristics, respiratory parameters, and lung ultrasound images were recorded soon after admission and compared between surfactant and non-surfactant groups. Adjusted odds ratio (OR) and diagnostic accuracy of LUS were calculated for SRT. Among 78 infants with RDS included in the final analysis, 62 received surfactant (79.48%). Median time of performing lung ultrasound was 50 min of life in both groups. Median LUS in the anterior and posterior chest areas of either side as well as total LUS was significantly higher in the surfactant group. After adjusting for other confounders, LUS was found to be a significant predictor of SRT (adjusted OR (95%CI): 1.55 (1.15-2.087)). Diagnostic accuracy of LUS was determined by receiver operating characteristic (ROC) curve analysis (AUC (95% CI): 0.751 (0.64-0.842), p < 0.001). A cutoff score of ≥ 9 for LUS was considered optimal for SRT (sensitivity (95%CI): 70.97% (57.87-81.45), specificity (95%CI): 68.75% (41.48-87.87)). CONCLUSION: Lung ultrasound is a valid diagnostic tool for SRT in Indian setting with a cutoff score ≥ 9. TRIAL REGISTRATION: CTRI/2021/11/038269. WHAT IS KNOWN: • Surfactant requirement in preterm infants with RDS has been traditionally based on FiO2 criteria. • Lung ultrasound score can predict the need for surfactant although majority of the studies originated in developed countries. WHAT IS NEW: • Lung ultrasound is a valid tool for surfactant replacement therapy even in developing countries like India.

Immunomodulatory fibrous hyaluronic acid-Fmoc-diphenylalanine-based hydrogel induces bone regeneration.

AIM: To investigate the potential of an ultrashort aromatic peptide hydrogelator integrated with hyaluronic acid (HA) to serve as a scaffold for bone regeneration. MATERIALS AND METHODS: Fluorenylmethyloxycarbonyl-diphenylalanine (FmocFF)/HA hydrogel was prepared and characterized using microscopy and rheology. Osteogenic differentiation of MC3T3-E1 preosteoblasts was investigated using Alizarin red, alkaline phosphatase and calcium deposition assays. In vivo, 5-mm-diameter calvarial critical-sized defects were prepared in 20 Sprague-Dawley rats and filled with either FmocFF/HA hydrogel, deproteinized bovine bone mineral, FmocFF/Alginate hydrogel or left unfilled. Eight weeks after implantation, histology and micro-computed tomography analyses were performed. Immunohistochemistry was performed in six rats to assess the hydrogel's immunomodulatory effect. RESULTS: A nanofibrous FmocFF/HA hydrogel with a high storage modulus of 46 KPa was prepared. It supported osteogenic differentiation of MC3T3-E1 preosteoblasts and facilitated calcium deposition. In vivo, the hydrogel implantation resulted in approximately 93% bone restoration. It induced bone deposition not only around the margins, but also generated bony islets along the defect. Elongated M2 macrophages lining at the periosteum-hydrogel interface were observed 1 week after implantation. After 3 weeks, these macrophages were dispersed through the regenerating tissue surrounding the newly formed bone. CONCLUSIONS: FmocFF/HA hydrogel can serve as a cell-free, biomimetic, immunomodulatory scaffold for bone regeneration.

Molecular Engineering of Rigid Hydrogels Co-assembled from Collagenous Helical Peptides Based on a Single Triplet Motif.

The potential of ultra-short peptides to self-assemble into well-ordered functional nanostructures makes them promising minimal components for mimicking the basic ingredient of nature and diverse biomaterials. However, selection and modular design of perfect de novo sequences are extremely tricky due to their vast possible combinatorial space. Moreover, a single amino acid substitution can drastically alter the supramolecular packing structure of short peptide assemblies. Here, we report the design of rigid hybrid hydrogels produced by sequence engineering of a new series of ultra-short collagen-mimicking tripeptides. Connecting glycine with different combinations of proline and its post-translational product 4-hydroxyproline, the single triplet motif, displays the natural collagen-helix-like structure. Improved mechanical rigidity is obtained via co-assembly with the non-collagenous hydrogelator, fluorenylmethoxycarbonyl (Fmoc) diphenylalanine. Characterizations of the supramolecular interactions that promote the self-supporting and self-healing properties of the co-assemblies are performed by physicochemical experiments and atomistic models. Our results clearly demonstrate the significance of sequence engineering to design functional peptide motifs with desired physicochemical and electromechanical properties and reveal co-assembly as a promising strategy for the utilization of small, readily accessible biomimetic building blocks to generate hybrid biomolecular assemblies with structural heterogeneity and functionality of natural materials.

A Spectroscopically Observed Iron Nitrosyl Intermediate in the Reduction of Nitrate by a Surface-Conjugated Electrocatalyst.

We report an iron-based graphite-conjugated electrocatalyst (GCC-FeDIM) that combines the well-defined nature of homogeneous molecular electrocatalysts with the robustness of a heterogeneous electrode. A suite of spectroscopic methods, supported by the results of DFT calculations, reveals that the electrode surface is functionalized by high spin (S = 5/2) Fe(III) ions in an FeN4Cl2 coordination environment. The chloride ions are hydrolyzed in aqueous solution, with the resulting cyclic voltammogram revealing a Gaussian-shaped wave assigned to 1H+/1e- reduction of surface Fe(III)-OH surface. A catalytic wave is observed in the presence of NO3-, with an onset potential of -1.1 V vs SCE. At pH 6.0, GCC-FeDIM rapidly reduces NO3- to ammonium and nitrite with 88 and 6% Faradaic efficiency, respectively. Mechanistic studies, including in situ X-ray absorption spectroscopy, suggest that electrocatalytic NO3- reduction involves an iron nitrosyl intermediate. The Fe-N bond length (1.65 Å) is similar to that observed in {Fe(NO)}6 complexes, which is supported by the results of DFT calculations.

PPARgamma agonism inhibits progression of premalignant lesions in a murine lung squamous cell carcinoma model.

The N-nitroso-trischloroethylurea (NTCU)-induced mouse model of squamous lung carcinoma recapitulates human disease from premalignant dysplasia through invasive tumors, making it suitable for preclinical chemoprevention drug testing. Pioglitazone is a peroxisome proliferator-activated receptor γ (PPARγ) agonist shown to prevent lung tumors in preclinical models. We investigated pioglitazone's effect on lesion development and markers of potential preventive mechanisms in the NTCU model. Female FVB/N mice were exposed to vehicle, NTCU or NTCU + oral pioglitazone for 32 weeks. NTCU induces the appearance of basal cells in murine airways while decreasing/changing their epithelial cell makeup, resulting in development of bronchial dysplasia. H&E and keratin 5 (KRT5) staining were used to detect and grade squamous lesions in formalin fixed lungs. mRNA expression of epithelial to mesenchymal transition (EMT) markers and basal cell markers were measured by qPCR. Dysplasia persistence markers desmoglein 3 and polo like kinase 1 were measured by immunohistochemistry. Basal cell markers KRT14 and p63, club cell specific protein and ciliated cell marker acetylated tubulin were measured by immunofluorescence. Pioglitazone treatment significantly reduced squamous lesions and the presence of airway basal cells, along with increasing normal epithelial cells in the airways of NTCU-exposed mice. Pioglitazone also significantly influenced EMT gene expression to promote a more epithelial, and less mesenchymal, phenotype. Pioglitazone reduced the presence of squamous dysplasia and maintained normal airway cell composition. This work increases the knowledge of mechanistic pathways in PPARγ agonism for lung cancer interception and provides a basis for further investigation to advance this chemoprevention strategy.

A Three-Arm Randomized, Controlled Trial of Different Nasal Interfaces on the Safety and Efficacy of Nasal Intermittent Positive-Pressure Ventilation in Preterm Newborns.

OBJECTIVES: To compare the safety and efficacy of different nasal interfaces for delivering non invasive positive pressure ventilation (NIPPV) in preterm neonates. METHODS: In this three-arm parallel group stratified nonblinded randomized trial involving 210 preterm neonates the participants were randomly allocated to 'nasal mask', 'nasal prongs' and '4 hourly rotation of masks and prongs' groups in a 1:1:1 ratio. The groups were further stratified by gestational age (26-316/7 wk versus 32-366/7 wk) and indication of NIPPV (primary versus post extubation). Primary outcome was incidence of NIPPV failure within 72 h of initiation. Secondary outcomes were moderate/severe nasal injury, requirement of surfactant post randomization, total duration of respiratory support, duration of NICU stay, common neonatal morbidities and mortality. RESULTS: Primary analysis revealed that mask group was superior to prongs and rotation groups in terms of reduction in NIPPV failure within 72 h (8.6%, 24.3%, 22.8%, p = 0.033), decreased incidence of moderate/severe nasal injury (8.6%, 22.8%, 11.4% p = 0.038), decreased requirement of surfactant (20%, 38.6%, 42.8%, p = 0.01) and reduction in total duration of respiratory support [median (interquartile range)-6 (3, 10) d, 7.7 (4.9, 19.2) d, 7 (5.5, 18.5) d, p = 0.005]. Post hoc analysis confirmed that nasal mask was superior to prongs with respect to primary outcome (p = 0.012) and also reduced surfactant requirement compared to both prongs (p = 0.015) and rotation (p = 0.003) groups. Other pairwise comparisons were not statistically significant. CONCLUSIONS: Administering NIPPV by nasal mask significantly decreases the incidence of NIPPV failure within first 72 h compared to nasal prongs and also reduces the requirement of surfactant compared to both prongs and rotation groups.

Impact of Airline Secondhand Tobacco Smoke Exposure on Respiratory Health and Lung Function Decades After Exposure Cessation.

BACKGROUND: Twenty-five percent to 45% of COPD is caused by exposures other than active smoking. Secondhand tobacco smoke (SHS) has been suggested as an independent cause of COPD, based on its association with increased respiratory symptoms and a small decrease in lung function, but its impact on respiratory health and lung function after exposure cessation has not been explored. RESEARCH QUESTION: What are the consequences of airline SHS exposure on respiratory health and lung function decades after cessation? STUDY DESIGN AND METHODS: We performed a cohort study involving flight attendants because of their exposure to SHS that stopped > 20 years ago. We included subjects ≥ 50 years of age with > 1 year vs ≤ 1 year of airline SHS exposure (ie, exposed vs unexposed). Respiratory quality of life, as determined by the St. George's Respiratory Questionnaire (SGRQ), was the primary outcome for respiratory health. Key secondary outcomes included general quality of life (the Rand Corporation modification of the 36-item Short Form Health Survey Questionnaire; RAND-36), respiratory symptoms (COPD Assessment Test; CAT), and spirometry. RESULTS: The study enrolled 183 SHS-exposed and 59 unexposed subjects. Exposed subjects were 66.7 years of age, and 90.7% were female. They were hired at 23.8 years of age, were exposed to airline SHS for 16.1 years, and stopped exposure 27.5 years before enrollment. Prior SHS exposure was associated with worsened SGRQ (6.7 units; 95% CI, 2.7-10.7; P = .001), RAND-36 physical and social function, and CAT vs unexposed subjects. SHS exposure did not affect prebronchodilator spirometry or obstruction, but was associated with lower postbronchodilator FEV1 and FEV1/FVC, total lung capacity, and diffusing capacity of the lungs for carbon monoxide in a subset of subjects. Former smoking and SHS exposure synergistically worsened SGRQ (ß = 8.4; 95% CI, 0.4-16.4; P = .04). SHS exposure in people who never smoked replicated primary results and was associated with worsened SGRQ vs unexposed people (4.7 units; 95% CI, 0.7-7.0; P = .006). INTERPRETATION: Almost three decades after exposure ended, airline SHS exposure is strongly and dose-dependently associated with worsened respiratory health, but less robustly associated with airflow abnormalities used to diagnose COPD.

Electrocatalytic reduction of nitrate by in situ generated cobalt nanoparticles.

The cobalt pyridinophane complex [Co(HN4)Cl2]+ (HN4 = 3,7-diaza-1,5(2,6)-dipyridinacyclooctaphane) is converted under catalytic conditions to an electrode-adsorbed species. Aqueous Co2+ solutions similarly deposit a species under these conditions. Surface characterization reveals the formation of Co nanoparticles. These nanoparticles are active in the electrocatalytic redution of aqueous nitrate.

Effect of Antenatal Dexamethasone in Late Preterm Period on Neonatal Hypoglycemia: A Prospective Cohort Study from a Developing Country.

OBJECTIVES: This study compared the risk of hypoglycemia within 72 h of life in infants with and without exposure to antenatal dexamethasone in the late preterm period (34-366/7 week's gestational age). METHODS: This prospective cohort study was conducted in a tertiary care neonatal unit of Eastern India from May 2021 to November 2021. Babies in the exposed group received at least one dose of antenatal dexamethasone in the late preterm period between 7 days before delivery and birth. 'Complete course' of antenatal steroid was defined as four doses of injection dexamethasone at 12 h intervals and <4 doses were considered as 'Partial course'. Primary outcome was incidence of hypoglycemia within 72 h of life, defined as whole blood glucose <45 mg/dl. RESULTS: Total 298 infants (98 in control, 134 in partial and 66 in complete group) were assessed for final outcome. No significant difference in outcomes were seen in the exposed group compared to unexposed group. However, incidence of hypoglycemia within 72 h (complete vs. partial p= 0.008, complete vs. control p=0.005) and 12 h of life (complete vs. partial p=0.013, complete vs. control p=0.013) was significantly less in complete steroid group. Logistic regression analysis revealed complete course of antenatal corticosteroid significantly decreased the risk of hypoglycemia [adjusted odds ratio, 95% confidence interval (CI) 0.15 (0.03-0.69), p=0.015]. Number needed to be exposed for one additional benefit was 7 (95% CI, 6.35-22.14). CONCLUSION: Complete course of dexamethasone administered to mothers at risk of late preterm delivery reduces risk of neonatal hypoglycemia within 72 h of life.

Dynamics and control of delayed rumor propagation through social networks.

Investigation of rumor spread dynamics and its control in social networking sites (SNS) has become important as it may cause some serious negative effects on our society. Here we aim to study the rumor spread mechanism and the influential factors using epidemic like model. We have divided the total population into three groups, namely, ignorant, spreader and aware. We have used delay differential equations to describe the dynamics of rumor spread process and studied the stability of the steady-state solutions using the threshold value of influence which is analogous to the basic reproduction number in disease model. Global stability of rumor prevailing state has been proved by using Lyapunov function. An optimal control system is set up using media awareness campaign to minimize the spreader population and the corresponding cost. Hopf bifurcation analyses with respect to time delay and the transmission rate of rumors are discussed here both analytically and numerically. Moreover, we have derived the stability region of the system corresponding to change of transmission rate and delay values.