Isolation of a wild-type virulent phage of Helicobacter pylori and its simulated treatments of gastrointestinal Hp in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To isolate the wild-type virulent phage of Helicobacter pylori (Hp) and simulate the treatments in vitro to investigate the methods for oral Hp-assisted penetration of the phage through the gastric barrier and offspring phage release for infection and treatment of gastrointestinal Hp.</p><p><b>METHODS</b>The Hp strain was cultured with the candle cylinder method and the virulent phage was isolated by single plate or double plate experiment. A simulated gastric juice was applied and the bactericidal effect of the phage was tested with double flats experiment.</p><p><b>RESULTS</b>After a 1.5-h treatment in simulated gastric juice, the orally derived Hp-borne phage was still capable of forming plaques while the control phage was not.</p><p><b>CONCLUSION</b>The oral Hp can help the phage resist the gastric juice and then infect the gastrointestinal Hp.</p>

Transforming of the drug resistance plasmid from Staphylococcus aureus into Escherichia coli / 南方医科大学学报

<p><b>OBJECTIVE</b>To discuss the possible mechanism of drug resistance transmission between Staphylococcus and Escherichia coli.</p><p><b>METHODS</b>The chloramphenicol resistance plasmid of Staphylococcus aureus was extracted to transform the sensitive Escherichia coli, and the drug-resistant Escherichia coli were screened by drug sensitivity test.</p><p><b>RESULTS</b>The drug-resistant Escherichia coli were successfully obtained.</p><p><b>CONCLUSION</b>Staphylococcus may have a natural shuttle plasmid of drug resistance, which can transform Escherichia coli under specific conditions.</p>

Effects of Newcastle disease virus on the expression of survivin and cell cycle in human tongue squamous carcinoma TSCCa cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of Newcastle disease virus (NDV) infection on the expression of survivin and cell cycle in human tongue squamous carcinoma TSCCa cells.</p><p><b>METHODS</b>The proliferation of TSCCa cells infected with NDV in vitro was evaluated by means of MTT assay, and survivin expression in the infected cells was detected using RT-PCR and Western blotting. Flow cytometry was performed to assess the changes in the cell apoptosis, cell cycle and cell proliferation index (PI) of the cells.</p><p><b>RESULTS</b>NDV infection resulted in decreased survivin expression and increased apoptosis of TSCCa cells, with reduced cell percentage in G2/M and S phases and lowered PI of the cells, showing significant differences from those of the negative control cells (P<0.05).</p><p><b>CONCLUSION</b>NDV infection can inhibit survivin expression, affect the cell cycle of TSCCa cells and induce their apoptosis.</p>