Objective To compare the effect of three methods in diagnosis of plague by detecting of Yersina pestis F1 antigen. Methods In natural foci of plague, wild animal samples, such as blood, liver, spleen,and lymphoid tissue were collected, and the three methods of enzyme linked immunosorbent assay (ELISA),reverse indirect hemagglutination assay(RIHA) and gold-immunochromatography assay(GICA) were employed to detect F1 antigen of Yersina pestis. Results Total of 414 infused organ samples of natural death and captured wild animals in natural foci of plague were determined. Positive samples detected by GICA and ELISA were the same,the positive rates were 5.31%(22/414), both positive and negative coincidence rates were consistently 100%. Only 18 samples were positive by retrial in 186 samples with more than 2 holes aggregation by preliminary examination of RIHA, with nonspecific agglutination rate of 40.6% (168/414) and positive rate of 4.35% (18/414). The positive coincidence rate was 81.82% (18/22) between RIHA with GICA and ELISA, and negative coincidence rate was statistically significant(t = 4.379, P ＜ 0.01). Conclusions ELISA, RIHA and GICA can be used for early diagnosis of plague by detecting F1 antigen. The results of RIHA have quantitative significance, with higher non-specific agglutination rate, and heavy workload of re-examination; GICA and ELISA has the same specificity and sensitivity, but the results of GICA is only qualitative. ELISA excluded the defect of RIHA and GICA, and combines the advantages of both methods.

Objective To analyse the feasibility of detecting F1 antibody to Yersinia pestis in flushing fluid of heart blood of Rhombomys opimus with enzyme linked immunosorbent assay(ELISA) method and its application value in surveillance of the disease. Methods Serum, flushing fluid of heart blood and infusion fluid of liver and spleen of Rhombomys opimus, which were caught by capture in the plague focus of Zunger basin in 2007, were taken to carry out detection for F1 antibodies to Yersinia pestis with ELISA method. The data were processed with SPSS 17.0. Results Positive rate and average titer of serum were 12.35%(11/162) and 25.35, of flushing fluid of heart blood were 10.49%(17/162) and 23.75 and of the infusion fluid of liver and spleen 6.79%(17/162) and 2240,respectively. No statistical difference was found in positive detection rate when it was compared between serum and flushing fluid of heart blood(χ2 = 1.333, P ＞ 0.05), but it was obviously different between serum and infusion fluid of liver and spleen(χ2 = 7.111, P ＜ 0.01 ) and between flushing fluid of heart blood and infusion fluid of liver and spleen(x2 = 6.250, P ＜ 0.05). There was a significant difference in average titer between serum, flushing fluid of heart blood and infusion fluid of liver and spleen(t = 2.290, 3.612, P ＜ 0.05 or ＜ 0.01 ). The plague F1 antibody positive coincidence rate of serum and flushing fluid of heart blood was 85.0%(17/20), of serum and infusion fluid of liver and spleen was 55.0% (11/20), and of flushing fluid of heart blood and infusion fluid of liver and spleen was 64.7%(11/17). Conclusions The ELISA method can detect Fl antibody in flushing fluid of heart blood,and the method is feasible in plague surveillance.

Objective To investigate the process of electrical activities when human brain deals with the facial sexual information. Methods Forty healthy college students in March 2005 were selected from Southern Medical University. All subjects participating in the experiment vohmtarily were right-handed with normal or corrected sight and never suffered from family history of mental disorder. 360 pictures of real human face (balf females and half males) strange to all participants, were used as the stimulus presented once one by one in randomized order on the screen with a stimulus duration of 800 ms and a stimulus onset asynchrony (SOA) of 1200 ms. Half subjects were asked to press the left button of a game-pad immediately after female face presentation and the right for male, the other half reversed. Event-related electroencephalogram (EEG) was recorded by 19 channels of international 10-20 system with linked earlobes as reference. EEG epochs from 100 ms before to 800 ms after stimulus were amplified by means of an ERPs system developed in our lab, digitized with sampling frequency of 1000 Hz, bandwidth of [0.1, 30] Hz and a notch of 50 Hz. Electrode impedance was less than 5 kΩ. Trial contaminated with ocular, muscular or any other type of artifacts were inspected visually and rejected. Each 60 stimuli of the same gender faces worked as an overlaying unit (the real overlay number was about 45-50 with bad epochs rejected). Three female and 3 male subjects were excluded owing to the bad ERP record quality and thus 34x6 epochs came from the rest ones. Results (1) The possible difference trend (but P>0.05) between male and female facial stimuli appeared at the frontal area in 40-100 ms after stimuli; (2) The significant difference between male and female appeared at the occipital in 140-160 ms after stimuli (P<0.05); (3) The significant difference between male and female appeared at the large frontal and occipital area in 200-260 ms after stimuli (P<0.05); (4) The significant difference between male and female appeared at the large central parietal in 280-300 ms after stimuli (P<0.05); (5) The significant difference or trend between male and female appeared at several areas in different time after 360 ms. Conclusion In different stage, different brain areas are activated for the facial sexual feature processing. Thus, our brain works as a network.