Plasma viral RNA load is widely accepted as the most relevant parameter to assess the status and progression of Simian immunodeficiency virus (SIV) infections. To accurately measure RNA levels of the virus, a one-step fluorescent quantitative assay was established based on the SYBR green Real-time reverse transcription-polymerase chain reaction (RT-PCR). The lower detection limit of the assay was 10 copies per reaction for the virus. This method was successfully applied to quantify SIVmac251 and SIVmac239 viruses produced in CEM×174 cells. Additionally, the performance of the SYBR green RT-PCR was assessed in a SIVmac251 infected rhesus macaque. The result demonstrated that the method could detect as little as 215 copies per milliliter of plasma and the dynamic pattern of viral load was highly consistent with previous results. With regard to convenience, sensitivity and accuracy our assay represents a realistic alternative to both branched-chain DNA (b-DNA) assays or real-time PCR assays based on TaqMan probes.

In order to meet the needs of contemporary society for medicine and cultivate high-quality compound medical talents, Chongqing Medical University has carried out the "organ system-centered" urogenital system integration curriculum reform. In the practice of integrated curriculum teaching, students have deepened their systematic understanding of medical knowledge, enhanced their enthusiasm and initiative in classroom learning, cultivated students' logical thinking ability, and improved students' innovative scientific research ability, by reorganizing the curriculum system, rewriting textbooks, improving the teaching environment, forming a teaching team, and reforming teaching methods, which laids the foundation for the further improvement of the medical curriculum.

Objective : To explore the antibacterial activity of epigallocatechin-3-gallate (EGCG) on P. gingivalis and the inhibitory effects on matrix metalloproteinases (MMPs) production induced by P. gingivalis. Methods: The antimicrobial effect of EGCG against planktonic cultures and biofilms of P. gingivalis was evaluated using microplate dilution assays. The microstructural changes in biofilms were studied using scanning electron microscopy (SEM). The inhibitory effect of EGCG on arginine gingipain (Rgp) and lysine gingipain (Kgp) activity of P. gingivalis was evaluated using synthetic chromogenic peptides and fluorogenic substrates. Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR analysis were used to assess MMP-1 and MMP-2 mRNA expression and secretion by human gingival fibroblasts (HGFs) stimulated with P. gingivalis in the presence or absence of EGCG, respectively. Results : The MIC and MBC of EGCG against P. gingivalis were 62.5 μg/mL and 500 μg/mL, respectively. EGCG can not only inhibit the biofilm formation of P. gingivalis but also has a scavenging effect on mature biofilms and can affect their viability. Additionally, 10 μg/mL and 50 μg/mL of EGCG inhibited the proteinase activities of Rgp and Kgp, respectively (P < 0.05). Finally, the mRNA expression and secretion of MMP-1 and MMP-2 by HGFs stimulated by P. gingivalis were significantly inhibited by 50 μg/mL of EGCG (P < 0.05). Conclusion EGCG exhibits antimicrobial effects against P. gingivalis and reduces the expression of MMPs by HGFs.