Recurrent respiratory syncytial virus infections in allergen-sensitized mice lead to persistent airway inflammation and hyperresponsiveness

Respiratory syncytial virus (RSV) infection is considered a risk factor for bronchial asthma; however, the synergy between allergen sensitization and RSV infection in the development of pulmonary inflammation and asthma has been controversial. In this study the effects of primary and recurrent RSV infection on allergic asthma were examined in a group of control, RSV-infected, Dermatophagoides farinae (Df) allergen-sensitized, and Df allergen-sensitized plus RSV-infected BALB/c mice. Primary RSV infection in Df-sensitized mice transiently increases airway responsiveness, which is accompanied by increases in eosinophilic infiltration, the expression of ICAM-1, and macrophage inflammatory protein-1alpha (MIP-1alpha) in the lung tissue. A secondary RSV infection persistently enhances airway responsiveness in Df-sensitized mice, with a concomitant increase in MIP-1alpha and RSV Ag load in lung tissues. Bulk cultures of thoracic lymph node mononuclear cells demonstrate that acute RSV infection augments both Th1- and Th2-like cytokines, whereas secondary and tertiary infections shift the cytokine profile in favor of the Th2-like cytokine response in Df-sensitized mice. The elevated total serum IgE level in the Df-sensitized mice persists following only RSV reinfection. Thus, recurrent RSV infections in Df-sensitized mice augment the synthesis of Th2-like cytokines, total serum IgE Abs, and MIP-1alpha, which are responsible for persistent airway inflammation and hyperresponsiveness, both of which are characteristics of asthma.     

Impact of Endobronchial Ultrasound (EBUS) Training on the Diagnostic Yield of Conventional Transbronchial Needle Aspiration for Lymph Node Stations 4R and 7

BackgroundThere is sparse literature on whether training in endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) improves the diagnostic yield of conventional TBNA (cTBNA).ObjectivesThe aim of this study was to evaluate the diagnostic yield of cTBNA before and after the introduction of EBUS.MethodsThis was a retrospective analysis of patients who underwent cTBNA at our center. The study was divided into two periods, before and after the introduction of EBUS at our facility. The diagnostic yield of cTBNA was compared between the study periods. Rapid on-site cytological examination was not available.ResultsA total of 1,050 patients (61.6% men; mean age 45.6 years) underwent cTBNA during the study period (849 before EBUS; 201 after EBUS). Sarcoidosis (n = 527) followed by bronchogenic carcinoma (n = 222) formed the most common indications for performing cTBNA. There was a significant increase in both the success of obtaining a representative sample (from 71% to 85%), and the diagnostic yield (from 33% to 49.5%) of cTBNA, after the introduction of EBUS. The increase in the diagnostic yield of cTBNA after introduction of EBUS remained significant even after adjusting for years of performing cTBNA and the type of anesthesia (topical vs. sedation and topical) on a multivariate analysis.ConclusionThe diagnostic yield of cTBNA at our facility increased after the introduction of EBUS-TBNA. However, given the retrospective nature of the study, prospective studies are required to confirm our findings.     

Study on reaction mechanism of bioleaching of nickel and cobalt from lateritic chromite overburdens

Depletion of high-grade ores and presence of significant quantities of metals in low-grade oxide ores has enforced to utilize the overburdens (COB) and wastes (low-grade ores) generated during mining operations. The impact of ore mineralogy and mineral–microbe interaction during bioleaching could not be ignored. Seeking to the need, a systematic study was performed to establish the reaction mechanism involved for recovery of nickel and cobalt from chromite overburden (COB), Sukinda, Orissa using pure culture of Aspergillus niger. Mineralogical analysis reveals a complete conversion of goethite into hematite phase leading to exposure of nickel particles into the micro-pores and cracks developed in the matrix which was initially found to be intertwined in the goethite lattice. As a result, it became more susceptible to attack by the fungal bio acids which in turn accelerate the dissolution rate. Organic acids like oxalic and citric acids were detected in the culture filtrate using HPLC. TEM analysis of the leached samples shows that nickel dissolute into the solution leaving a porous space in the matrix of the hematite by forming nickel oxalate or nickel citrate. Kinetics of the nickel bioleaching was studied to support the mechanism of the reaction. It was observed that the initial rate of reaction follows the chemical control dissolution reaction where as the later part fits to shrinking core model. 18% of nickel and 37.8% of cobalt was recovered from pre-treated COB at 2.5% pulp-density with 10% (v/v) fungal inoculum at 30 °C within 25 days in shake flask while 32.5% of nickel and 86% of cobalt was recovered in bioreactor.     

Marker-assisted selection for grain number and yield-related traits of rice (Oryza sativa L.)

Physiology and Molecular Biology of Plants - Continuous rise in the human population has resulted in an upsurge in food demand, which in turn demand grain yield enhancement of cereal crops,...     

Molecular dynamics simulation of the effects of single (S221P) and double (S221P and K216E) mutations in the hemagglutinin protein of influenza A H5N1 virus: a study on host receptor specificity

Avian influenza viruses of subtype H5N1 circulating in animals continue to pose threats to human health. The binding preference of the viral surface protein hemagglutinin (HA) to sialosaccharides of receptors is an important area for understanding mutations in the receptor binding site that could be the cause for avian-to-human transmission. In the present work, we studied the effect of two receptor binding site mutations, S221P singly and in combination with another mutation K216E in the HA protein of influenza A H5N1 viruses. Docking of sialic acid ligands corresponding to both avian and human receptors and molecular dynamics simulations of the complexes for wild and mutant strains of H5N1 viruses were carried out. The H5N1 strain possessing the S221P mutation indicated decreased binding to α2,3-linked sialic acids (avian receptor, SAα2,3Gal) when compared to the binding of the wild-type strain that did not possess the HA-221 mutation. The binding to α2,6-linked sialic acids (human receptor, SAα2,6Gal) was found to be comparable, indicating that the mutant strain shows limited dual receptor specificity. On the other hand, the S221P mutation in synergism with the K216E mutation in the binding site, resulted in increased binding affinity for SAα2,6Gal when compared to SAα2,3Gal, indicative of enhanced binding to human receptors. The in-depth study of the molecular interactions in the docked complexes could explain how co-occurring mutations in the HA viral protein can aid in providing fitness advantage to the virus, in the context of host receptor specificity in emerging variants of H5N1 influenza viruses.     

Mangroves diversity and erosion mitigation performance in a low salinity soil area: case study of Vinh City,Vietnam

Wetlands Ecology and Management - This study aims to investigate the diversity of mangrove species and their soil erosion mitigation performance in Hung Hoa Mangrove Forest, Vinh City, Vietnam....     

Control of scabies in a tribal community using mass screening and treatment with oral ivermectin -A cluster randomized controlled trial in Gadchiroli,India

BackgroundScabies is often endemic in tribal communities and difficult to control. We assessed the efficacy of a community-based intervention using mass screening and treatment with oral ivermectin in controlling scabies.Methods/ FindingsIn this cluster randomised controlled trial, 12 villages were randomly selected from a cluster of 42 tribal villages in Gadchiroli district. In these villages, trained community health workers (CHWs) conducted mass screening for scabies. The diagnosis was confirmed by a physician. Six villages each were randomly allocated to the intervention and usual care arm (control arm). In the intervention arm (population 1184) CHWs provided directly observed oral ivermectin to scabies cases and their household contacts. In the usual care arm (population 1567) scabies cases were referred to the nearest clinic for topical treatment as per the standard practice. The primary outcome was prevalence of scabies two months after the treatment. Secondary outcomes were prevalence of scabies after twelve months of treatment and prevalence of impetigo after two and twelve months of treatment. Outcomes were measured by the team in a similar way as the baseline. The trial was registered with the clinical trial registry of India, number CTRI/2017/01/007704.In the baseline, 2 months and 12 months assessments 92.4%, 96% and 94% of the eligible individuals were screened in intervention villages and 91.4%, 91.3% and 95% in the usual care villages. The prevalence of scabies in the intervention and usual care arm was 8.4% vs 8.1% at the baseline, 2.8% vs 8.8% at two months [adjusted relative risk (ARR) 0.21, 95% CI 0.11–0.38] and 7.3% vs 14.1% (ARR 0.49, 95% CI 0.25–0.98) at twelve months The prevalence of impetigo in the intervention and usual care arm was 1.7% vs 0.6% at baseline, 0.6% vs 1% at two months (ARR 0.55, 95% CI 0.22–1.37) and 0.3% vs 0.7% at 12 months (ARR 0.42, 95% CI 0.06–2.74). Adverse effects due to ivermectin occurred in 12.1% of patients and were mild.ConclusionsMass screening and treatment in the community with oral ivermectin delivered by the CHWs is superior to mass screening followed by usual care involving referral to clinic for topical treatment in controlling scabies in this tribal community in Gadchiroli.