ABSTRACT
Objective To develop a micro-circumstance airtight cabin for in the study of biological aerosols detection with such functions as airflow control and temperature and humidity detection .Methods Wind speed sensors , temperature and humidity sensors , electrical control valves , high efficiency filters and the vacuum pump formed the micro-circumstance regulating system .The techniques of airflow direction control , temperature compensation , air pressure control and aerosol uniformity distribution were used .Numerical simulation of aerosol concentration distribution in the airtight cabin was achieved using Fluent software .The bioaerosol concentration in different locations was tested by experiments .Results The micro-circumstance airtight cabin consisted of an airtight cabin and a control cabin .The control cabin used a single-chip microprocessor to provide air supply and exhaust air to the airtight cabin in a seaparate exhaust mode and cyclic ventilation mode.It worked under a negative pressure condition .Through numerical simulation,the aerosols were distributed through-out the cabin after five minutes of generation and the bottom airflow arrived at the top .The distribution of aerosol concentra-tion was approximately uniform .Conclusion The micro-circumstance airtight cabin is suited to various bioaerosols testing research thanks to its negative pressure working without bioaerosol leakage .
ABSTRACT
Objective To investigate the immunogenicity of mycobacteriophage D29 (phage D 29) in guinea pig models with different delivery routes,and provide information for the application of phages in tuberculosis (TB) therapy.Methods Hartley guinea pigs were administrated with phage D29 through inhalation,intranasal drop or subcutaneous injection for 6 times within 35 days.7H9 broth aerosol inhalation and 0.85 ％ NaCl solution aerosol inhalation were set as solvent and negative controls,respectively.Anti-phage D29 neutralizing antibodies in sera collected weekly were measured by phage reduction neutralizing test (PRNT) and cytokine levels (interleukin-2,interleukin-4 and interferon-γ) were detected at day 35 by enzyme linked immunosorbent assay (ELISA).The data were analyzed by ANOVA and nonparametric test.ResultsNeutralizing antibodies were both negative in two control groups,while low-titer neutralizing antibodies (below 1 ∶ 100) appeared in inhalation and intranasal drop groups only at day 7 and day 14. Nevertheless, neutralizing antibodies were continuously detected in subcutaneous injection group,which increased rapidly and reached 1∶ 16 365.6 at day 35. After 35 days of experiments,serum concentrations of interleukin-2 (x2 =2.7605,P＞0.05),interleukin-4 (F=2.17,P＞0.05) and interferon-γ(F=0.75,P＞0.05) among three treatment groups and two control groups were all not significantly different.ConclusionsThe titer of anti-phage 29 neutralizing antibodies induced by inhalation or intranasal drop administration of phage D29 are both significantly lower than subcutaneous injection.Phage D29 administration doesn’t change the levels of cytokines,which indicates that it may not break the helper T cell (Th)1/Th2 balance.
