The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was perf...The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients.Eight patients with head and neck cancers were involved in this study.For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy.A total of 147 232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis,representing 3 460 species level operational taxonomic units(OTUs) and 140 genus level taxa.Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics.Moreover,the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves.This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.展开更多
Aim The purpose of this study was to develop a mathe-matical model to quantitatively describe the passive trans-port of macromolecules within dental biofilms. Methodology Fluorescently labeled dextrans with different ...Aim The purpose of this study was to develop a mathe-matical model to quantitatively describe the passive trans-port of macromolecules within dental biofilms. Methodology Fluorescently labeled dextrans with different molecular mass （3 kD,10 kD,40 kD,70 kD,2 000 kD） were used as a series of diffusion probes. Streptococcus mutans,Streptococcus sanguinis,Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope. Results Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function,not only the relationship between average concentration of steady-state and molecule weights can be analyzed,but also that between penetrative time and molecule weights. Conclusion This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Further-more,an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.展开更多
基金supported by a grant from the National Natural Science Foundation(No.81070826/30872886) of Chinapartly sponsored by Shanghai Rising-Star Program(No.12QH1401400)funded by the Shanghai Jiao Tong University(Grant No.YG2011MS67)
文摘The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients.Eight patients with head and neck cancers were involved in this study.For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy.A total of 147 232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis,representing 3 460 species level operational taxonomic units(OTUs) and 140 genus level taxa.Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics.Moreover,the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves.This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.
基金supported by a grant from the National Natural Science Foundation of China (NSFC) No. 81070826/30872886/30400497Sponsored by Shanghai Rising-Star Program No. 09QA1403700+1 种基金funded by Shanghai Leading Academic Discipline Project (Project Number: S30206)the Science and Technology Commission of Shanghai (08DZ2271100)
文摘Aim The purpose of this study was to develop a mathe-matical model to quantitatively describe the passive trans-port of macromolecules within dental biofilms. Methodology Fluorescently labeled dextrans with different molecular mass （3 kD,10 kD,40 kD,70 kD,2 000 kD） were used as a series of diffusion probes. Streptococcus mutans,Streptococcus sanguinis,Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope. Results Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function,not only the relationship between average concentration of steady-state and molecule weights can be analyzed,but also that between penetrative time and molecule weights. Conclusion This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Further-more,an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.
