Objective To determine the localization of histidine triad protein(Htp) on Streptococcus suis 2(S.suis 2) and the effect of disruption of sortase A(srtA) gene on the expression level of Htp.Methods Antiserum against Htp was prepared by immunizing rabbit with recombinant Htp.Bioinformatics analysis was adopted to evaluate the amino acid sequence characteristic of Htp.Flow cytometry was applied to localize Htp on S.suis 2 bacteria.Results Bioinformatics analysis demonstrated that Htp had the characteristic of cell surface protein with signal sequence and transmembrane sequence.Flow cytometry showed the localization of Htp was on the surface of S.suis 2 and the expression level of Htp on cell surface decreased by deletion of srtA.Conclusions Htp is located on the cell surface of S.suis 2.The results provide a foundation for further investigation of the role of Htp in the infection of S.suis 2.

Streptococcal superantigens play an important role in many human diseases.In this paper,we mainly discuss the progress in the researches on streptococcal superantigens in such aspects as their structures,biological and pathophysiological properties,expression regulation,and their significance in the management of tumors.

Objective To investigate the characteristics of the depression during emotional processing.Methods 24 participants with first episode of depression and healthy controls were assessed with HAMD scale,using DTI to dectect values of white matter FA,and using fMRI with pictures of emotional stimuli;thus results related with imagings were produced.The results were statistically analyzed.Results The brain areas indicating FA values deference with statistial significance in depression patients compared with the control ones included:left and right frontal lobe (left frontal lobe depression group 0.324 ± 0.090,control group 0.467 ± 0.072,P ＜ 0.01),corpus callosum knee (depression group 0.614 ±0.146,control group 0.734 ±0.063,P＜0.01),anterior cingulate gyrus (depression group 0.222 ±0.035,control group 0.343 ±0.021,P＜0.01) ;the fronal FA values in depression grop were negatively correlated with the duration of bilateral frontal white matter (r =-0.555,P ＜ 0.01).The activation of emotional brain regions stimulated by pictures includes frontal cortex-subcortical reticular system,and the hypothalamus and limbic system.There was a significant difference between two groups.Conclusion There may be abnormal emotional processing dystunction in patients with depression.It may be the pathological basis to have frontal white matter fiber tracts broken.