[Real-time detection of mast cell degranulation in anaphylactoid reaction].

OBJECTIVE: To establish a new, real time, dynamic and direct optical detection method for mast cell degranulation caused by anaphylactoid reaction. METHOD: A CD63-GFP plasmid was constructed and introduced steadily into rat basophilic leukemia (RBL-2H3) cells. The movements of CD63-GFP, which was located on both the granule membranes and the plasma membranes of RBL cells stimulated by Compound 48/80, were studied by confocal laser scanning microscope (CLSM) and total internal reflection fluorescence microscope (TIRFM) both inside and on the surface of living RBL-2H3 cells. RESULT: Before antigen stimulation, most granules with CD63-GFP hardly moved in RBL cells. However, after antigen stimulation, the granules moved dramatically. They reached the plasma membranes in a few minutes and fused with them instantaneously. The velocity of the granule movement toward the plasma membranes on antigen stimulation was calculated to be 0.05 micron x s(-1). CONCLUSION: Analysis of the movement of each granule provided a new insight into the elementary process of degranulation. The method is rapid, sensitive and reliable, which could be used as a new detection method for anaphylactoid reaction in vitro.

Anti-biofilm activity of TanReQing, a Traditional Chinese Medicine used for the treatment of acute pneumonia.

AIM OF THE STUDY: TanReQing (TRQ) is a Traditional Chinese Medicine used to treat biofilm related upper respiratory infections. However, its anti-biofilm mechanism remains unknown. The aim of this study is to investigate the anti-biofilm activity of TRQ and to compare it with penicillin in vitro. MATERIALS AND METHODS: The effect of TRQ and penicillin on free state, biofilm formation and mature biofilms of Staphylococcus aureus was studied using the crystal violet and the XTT reduction assays. Confocal Laser Scanning Microscopy was used to generate the 3D-transmission-fluorescence images of drug treated Staphylococcus aureus biofilms. RESULTS: The in vitro data showed that TRQ is less effective than penicillin in eradicating the planktonic bacteria. However, the anti-biofilm activity of TRQ is different from that of penicillin. TRQ not only does inhibit the formation of the Staphylococcus aureus biofilm, but also kills the viable cells embed in Staphylococcus aureus biofilm matrix. CONCLUSIONS: This study shows for the first time that TRQ possesses an antibiotic activity against biofilm bacteria. This activity is different from that of penicillin. The evaluation system applied in this study can be utilized for identifying new anti-biofilm products from Traditional Chinese Medicine.