Size- and Dose-Dependent Antiviral Effects of Silver Nanoparticles
NCTR scientists have demonstrated both size- and dose-dependent antiviral effects of silver nanoparticles (AgNPs) in in vitro assays using feline calicivirus (FCV) as a surrogate for human norovirus. Whereas no effect was observed with 75 and 110 nm-sized AgNPs, treatment of cultures with 10 nanometer (nm)-sized AgNPs (at doses of 50 and 100 micrograms per milliliter [µg/mL]) completely inactivated FCV within 2-4 hours of exposure, resulting in:
- decrease in the viral titer
- absence of cytopathic effects in Crandell-Rees Feline Kidney cells
- reduction in viral capsid protein levels.
The use of AgNPs as antibacterial agents has increased in consumer-use products; however, its use as an antiviral agent is still an area of active research. This study is now availableonline at Foodborne Pathogens and Disease.
For additional information, please contact Sangeeta Khare, Ph.D., Division of Microbiology, FDA/NCTR.
Pediatric Anesthetic NeuroDevelopment Assessment (PANDA) Symposium
Dr. Merle Paule, Director of the Division of Neurotoxicology, NCTR, gave a presentation at the 5th PANDA Symposium held in New York, NY, on April 16-17, 2016. The presentation focused on NCTR’s nonhuman primate studies on the long-lasting cognitive deficits associated with neonatal general anesthesia and summarized data from several recent publications. The symposium, sponsored in part by the SmartTots public-private partnership between FDA and the International Anesthesia Research Society, provides a forum for presentation and discussion of clinical and preclinical anesthesia studies being conducted at multiple U.S. institutions.
For additional information, please contact Merle Paule, Ph.D., Director, Division of Neurotoxicology, FDA/NCTR.
Analyzing NGS Data With An Unusual Approach
NCTR scientists have developed a method, using concepts normally applied to computerized text analysis of publications, to identify gene-phenotype relationships and biomarkers from next generation sequencing (NGS) data. The prototype analysis successfully classifiedSalmonella enterica strains into serotypes utilizing fliC — one of the serotype-determinant genes. Theprocess can be modified to analyze other organisms.
Similar to how computerized text mining detects the relevant content- of-interest in a publication by looking at word relationships, the:
- sequence is considered the "document"
- Salmonella sequence-SNPs are considered the "words."
The serotype (or other biomarkers of interest) can be deduced by analyzingthe Salmonella sequence-SNPrelationships in the NGS data of different Salmonella strains, mirroring document-word relationships in text mining.
The method provides a new approach to perform large-scale comparative and evolutional studies from NGS data for understanding and decoding hidden genetic information that is contained in big data sets of biological and medical information.
For additional information, please contact Wen Zou, Ph.D., Division of Bioinformatics and Biostatistics, FDA/NCTR