Objective To develop a nested PCR for the detection of early syphilis and genotyping of Treponema pallidum (TP), and to investigate the distribution of genotypes of TP in Guangzhou. Methods Specimens were consecutively collected from genital ulcers of patients with suspected chancre during 2002-2004, and were detected by dark-field microscopy and nested PCR. The acidic repeat protein (arp) gene and the T. pallidum repeat (tpr) gene family were amplified with the positive specimens above. The number of repeats presented in the arp gene and the restriction fragment length polymorphism by Mse I in the tpr gene were analyzed by electrophoresis. The strains were genotyped according to Pillay's criteria. Results Out of 62 patients with suspected chancre, 33 cases (53.2%) were positive by dark-field microscopy and 54 cases (87.1%) by nested PCR. Of 47 TP-positive specimens genotyped by arp gene, 36 (76.6%) were type 14, while of 49 cases genotyped by tpr gene 39 (79.6%) were type d. By combining genotypes of arp and tpr genes, 7 genotypes were found, including 14d (31, 66.0%), 13d (5, 10.6%), 14b (4, 8.5%), 12b (3, 6.4%), 12d (2, 4.3%), 15d(l, 2.2%) and 14i (1, 2.2%). Conclusions Nested PCR shows a high sensitivity in early detection of TP. Genotype 14d seems the predominant type of TP in Guangzhou.

Bluetongue virus is an arbovirus that seriously harms ruminants such as sheep,this study aims to investigate the molecular mechanism of bluetongue virus infection and host cell interferon antiviral immune response.The study was conducted to characterize the mRNA expression of inter-feron pathway genes by real-time fluorescence quantitative PCR,as well as Western blot analysis of MDA5,TRAF3,RIG-Ⅰ,and TBK1 protein expression in BHK-21 cells induced by BTV with a multiplicity of infections(MOI)of 1 for 18,24,and 36 h.The results showed that the most pro-nounced changes in the expression of interferon signaling pathway genes were observed at 24 h of induction,the gene mRNA expression levels of the IFN-α,IFN-β,RIG-Ⅰ,TBK1,MDA5,VISA,and TRAF3 genes were upregulated.However,the mRNA expression levels of IKKε and TRAF6 genes were downregulated.At the protein level,MDA5 and TBK1 proteins were upregulated while RIG-1 and TRAF3 proteins were downregulated,which showed that BTV infection induces a typeⅠ interferon immune response in BHK-21 cells.This study lays the foundation for further exploring the antiviral immunity mechanism of IFN-Ⅰ signaling pathway regulatory genes in host cells infected with BTV infection.

China has a large, advanced, and rapidly aging population, coupled with a trend of decreasing birth rates that is exacerbating the issue of an aging society. It is expected that by 2030, China will become a hyper-aged society. As the demographic dividend gradually diminishes, the working-age population is shrinking in size and becoming increasingly older, making elderly labor force an important resource. Japan and South Korea have accumulated rich experience in promoting the healthy employment and occupational health services for the elderly workforce. It is necessary for China to thoroughly consider the issue and implement corresponding measures. This article compared and analyzed the current employment situation of aging populations in China, Japan, and South Korea, revealing that Japan and South Korea presented certain advantages in healthy employment policies, occupational health measures for the elderly, and digital economy. Taking into account the circumstances in China, we can further strengthen occupational health promotion activities, optimize employment structure, utilize new technologies such as artificial intelligence, promote active aging, ensure the sustainable development of elderly labor force resources, steadily enhance comprehensive national strength, and meet the increasing demand for better quality of life among the people.

Humans ; Asthma/drug therapy* ; Biological Therapy