Critical Role of TLR4 in Human Metapneumovirus Mediated Innate Immune Responses and Disease Pathogenesis

Human metapneumovirus (hMPV) is one of the main causes of acute respiratory tract infections in children, elderly and immunocompromised patients. The mammalian Toll-like receptors (TLR) were identified as critical regulators of innate immunity to a variety of microbes, including viruses. We have recently shown that hMPV-induced cytokine, chemokine and type I interferon secretion in dendritic cells occurs via TLR4, however, its role in hMPV-induced disease is unknown. In this study, wild-type(WT) and TLR4-deficient mice (TLR4^−/−) were infected with hMPV and examined for clinical disease parameters, such as body weight loss and airway obstruction, viral clearance, lung inflammation, dendritic cell maturation, T-cell proliferation and antibody production. Our results demonstrate that absence of TLR4 in hMPV-infected mice significantly reduced the inflammatory response as well as disease severity, shown by reduced body weight loss and airway obstruction and hyperresponsiveness (AHR), compared to WT mice. Levels of cytokines and chemokines were also significantly lower in the TLR4^−/− mice. Accordingly, recruitment of inflammatory cells in the BAL, lungs, as well as in lymph nodes, was significantly reduced in the TLR4^−/− mice, however, viral replication and clearance, as well as T-cell proliferation and neutralizing antibody production, were not affected. Our findings indicate that TLR4 is important for the activation of the innate immune response to hMPV, however it does play a role in disease pathogenesis, as lack of TLR4 expression is associated with reduced clinical manifestations of hMPV disease, without affecting viral protection.     

Curdlan-like exopolysaccharide production by <Emphasis Type="Italic">Cellulomonas flavigena</Emphasis> UNP3 during growth on hydrocarbon substrates

Cellulomonas flavigena UNP3, a natural isolate from vegetable oil contaminated soil sample has been studied for growth associated exopolysaccharide (EPS) production during growth on glucose, groundnut oil and naphthalene. The EPS showed matrix formation surrounding the cells during scanning electron microscopy. Cell surface hydrophobicity and emulsifying activity studies confirmed the role of EPS as bioemulsifier. Emulsifying activity was found to increase with time (0.2 U/mg for 10 min to 0.27 U/mg for 30 min). Emulsification index, E₂₄ value increased with the increase in EPS concentration. Degradation of polyaromatic hydrocarbons was confirmed using gas chromatography analysis. FTIR analysis showed presence of characteristic absorbance at 895.10 cm⁻¹ for β-configuration of glucan. NMR studies also revealed EPS produced by C. flavigena UNP3 as a linear β-1, 3-d-glucan, and a curdlan like polysaccharide.     

Antiaflatoxigenic Potential of Cell-Free Supernatant from Lactobacillus plantarum MYS44 Against Aspergillus parasiticus

Probiotics and Antimicrobial Proteins - The study aims to evaluate the cell-free supernatant (CFS) from Lactobacillus plantarum strain MYS44 against the growth and aflatoxin production by...     

Environmental Factors Associated with High Fly Densities and Diarrhea in Vellore,India

Diarrhea causes significant morbidity and mortality in Indian children under 5 years of age. Flies carry enteric pathogens and may mediate foodborne infections. In this study, we characterized fly densities as a determinant of infectious diarrhea in a longitudinal cohort of 160 urban and 80 rural households with 1,274 individuals (27% under 5 years of age) in Vellore, India. Household questionnaires on living conditions were completed at enrollment. Fly abundance was measured during the wet and dry seasons using fly ribbons placed in kitchens. PCRs for enteric bacteria, viruses, and protozoa were performed on 60 fly samples. Forty-three (72%) fly samples were positive for the following pathogens: norovirus (50%), Salmonella spp. (46.7%), rotavirus (6.7%), and Escherichia coli (6.7%). Ninety-one episodes of diarrhea occurred (89% in children under 5 years of age). Stool pathogens isolated in 24 of 77 (31%) samples included E. coli, Shigella spp., Vibrio spp., Giardia, Cryptosporidium, and rotavirus. Multivariate log-linear models were used to explore the relationships between diarrhea and fly densities, controlling for demographics, hygiene, and human-animal interactions. Fly abundance was 6 times higher in rural than urban sites (P < 0.0001). Disposal of garbage close to homes and rural living were significant risk factors for high fly densities. The presence of latrines was protective against high fly densities and diarrhea. The adjusted relative risks of diarrheal episodes and duration of diarrhea, associated with fly density at the 75th percentile, were 1.18 (95% confidence interval [CI], 1.03 to 1.34) and 1.15 (95% CI, 1.02 to 1.29), respectively. Flies harbored enteric pathogens, including norovirus, a poorly documented pathogen on flies.     

Ultra-performance liquid chromatography-tandem mass spectrometric method for the determination of Artemisinin in rat serum and its application in pharmacokinetics

A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to quantify artemisinin in rat serum. The lower limit of quantification (LLOQ) was 4 ng/mL. The calibration curve was linear from 4 ng/mL to 10,000 ng/mL (R=0.998). The assay was based on the selected reaction monitoring (SRM) transitions at m/z 305.4-151.10 for artemisinin and m/z 335.2-163.10 for arteether (internal standard). The artemisinin and internal standard can be separated from endogenous interferences in rat serum. Inter- and intra-day assay variation was less than 15%. The extraction recoveries ranged from 80.0 to 107.3% at the three concentrations (5000, 2000, and 200 ng/mL). This method was successfully applied to pharmacokinetic studies of artemisinin after intravenous and oral administration to rats.     

A comparative proteome assay on the quality of yardlong bean pods as influenced by the organic and inorganic nourishment systems

The assumption of enhanced nutritional quality of food produced through the organic systems against the inorganic systems is under constant challenge. Changes in nutritional quality under varying methods of crop nourishment, if any, should be through the differential translation of proteins and hence should be reflected in the proteome profile. The present study was undertaken to understand the effect of organic and inorganic crop nourishments on the nutritional quality of yardlong bean, through two-dimensional proteome profiling. Yardlong beans were raised separately under organic and inorganic nourishment and the proteome of pods was profiled. The differentially expressed and upregulated proteins from immature and mature pods from both the systems were characterized through MALDI-ToF/MS. Under both the production systems, differentially expressed proteins were the contributors to antioxidant properties at different pod maturity stages and pod quality was proven to be independent of crop nourishment system. This study does not support the hypothesis that organically produced foods will be nutritionally superior.     

Rhinosporidiosis in Delhi, North India: Case Series from a Non-endemic Area and Mini-review

We report three cases of rhinosporidiosis from migrant population of Delhi. Three male patients had sino-nasopharyngeal, nasopharyngeal and nasal rhinosporidiosis, respectively. One patient gave a history of bathing in stagnant water. The diagnosis was made by clinical presentation and microscopic observation of characteristic sporangia of Rhinosporidium seebri in mycological and histopathological investigations. All the patients were successfully treated with complete surgical excision of lesions and cauterization of base. There were no recurrences.