HMGB-1, an ubiquitously expressed 25-KD nucleoprotein among mammals, belongs to the HMG family. Recent studies have identified that HMGB-1 is secreted by activated monocytes/macrophages via a non-classical ,vesicle-mediated secretory pathway. Extracellular HMGB-1 is an important proinflammatory cytokine. It participates in the pathogenesis of many diseases such as rheumatoid arthritis, sepsis , acute lung injury, and even leads animals death. Further studies of the mechanism and function of extracellular HMGB-1 may provide a novel strategy for the diagnosis and treatment of these diseases.

Objective To detect mutations of the RET proto-oncogene in a family with multiple endocrine neoplasia type 2A (MEN2A). Methods Nineteen family members were recruited in the study. The phenotype of the members with MEN2A were observed. PCR was performed to amplify exans 10 and 11 of the RET proto-oncogene. The PCR products were purified and a direct DNA sequence analysis was performed. Results The Cys (TGC)634Arg(CGC) missense mutation and Gly( GGT)691Ser(AGT) in exon 11 of the RET proto-oncogene were both detected in four members of the family. Only the pelymorphism Gly691Ser in exon 11 of the RET proto-oncogene was detected in one member. The results of the ultrasound examination were shown as follows: two members with bilateral thyroid, one side of parathyroid and adrenal solid lesions; one member with bilateral thyroid and one side of adrenal solid lesions; one member with bilateral thyroid and adrenal and one side of parathyroid solid lesions; and one member with multiple thyroid small nodules. Additionally, another three members with abnormal findings on ultrasound examinations had no gene mutation. Conclusion Analysis of RET gene identifies a TGC to CGC mutation at codan 634 and the polymorphism Gly691 Set in exon 11 in this family with MEN2A. Direct DNA sequencing analysis is useful in diagnosis of MEN2A at gene level.

Objective:To analyze the changes in biological characteristics including infectivity, growth and pathogenicity of Chlamydia muridarum ( Cm) after serial passage in vitro in special conditions in order to provide reference for screening attenuated live vaccines and virulence-related genes. Methods:Wild-type Cm strain (G0) was cultured for several passages using conventional cell culture method under alternate unassisted and assisted culture conditions. Then, the 28th generation (G28) of Cm was selected and compared with the parental G0 strain in terms of centrifugation dependence, attaching ability, intracellular growth curve, plaque size and fallopian tube lesions after genital tract infection in a mouse model. Results:Compared with the parental G0 strain, the G28 strain showed significantly decreased dependence on centrifugation during cell infection ( P<0.05) and increased attachment capacity to cells ( P<0.05). No significant differences were observed in the growth curves 32 h after cell infection or in the plaque sizes between the parental G0 and G28 strains. In the in vivo virulence test, fallopian tube lesions were observed in 87.5% of G0-infected mice and 37.5% of G28-infected mice ( P<0.05). Conclusions:Compared with the parental G0 strain, the G28 strain showed significantly enhanced in vitro infection ability, but decreased in vivo pathogenicity, which brought hope for further identification of virulence genes, isolation of attenuated strains with single genotype and development of live attenuated Chlamydia vaccines.