[Comparative analysis on meteorological condition for persistent haze cases in summer and winter in Beijing].

Summer is another peak season for haze besides winter in Beijing area, which is different from that in South China. The data of microwave radiometer, profiler, sounding, AWS, NCEP (NCAR) and air pollution monitors were used in the analysis of two haze cases which occurred in winter and summer, respectively. Both cases lasted for 6 days. This research focused on the difference in the mechanism of the formation and persistence of haze cases in various seasons. In winter, north-westerly flow dominated Beijing at upper-levels and a few of shallow troughs passed by during persistent haze development. The main meteorological reasons for lower visibility in 6 days were: there was an inversion in the boundary layer all the time; wind was weak at surface and moisture went up gradually. The change of inversion height and humidity day and night led to the diurnal variation of PM2.5 concentration and visibility. The surface wind speed kept lower because the weak cold air could not often hit the surface during the haze case. In addition, three factors played key roles in the inversion formation in boundary layer. One was that the rapid decrease in the surface temperature after sunset due to the radiation. At the same time, there was some warm advection at upper boundary layer. The third one attributed to the temperature increase after the air flowing over the mountains and down. However, in summer, regional transportation of aerosol, sustained convective stability and high air saturation were very important factors for the haze formation. Under the sub-tropic high control, the wind direction at lower troposphere was south. The PM2.5 concentration went up when the speed of south wind increased. The south flow caused by both synoptic scale systems and mountain-valley breeze near Beijing transported the aerosol northward from higher polluted area. There was no inversion in the summer haze case. But, the convective inhibition was kept over 200 J x kG(-1). As the result, it was not favorable for the pollutant diffusion upward. Furthermore, the level of free convection also changed during the day and at the night, which had similar effect on the PM2.5 concentration and visibility as the daily variation of inversion. In conclusion, these cases in winter and summer were categorized into two different kinds of persistent haze. The main reason leading to the difference was the synoptic pattern.

[Effect of ginsenoside Rh2 on transplanted-tumor and expression of JAM in mice].

OBJECTIVE: To discuss the anti-tumor activity of ginsenoside Rh2, we observed the expressions of the junction adhesion molecul (JAM) in transplanted-tumor in mice. METHOD: The models of 40 transplanted-tumor mice that were established by subsequently injecting cancer ascite of mice (S180) with 0.2 mL per mouse into the preepipodite skin were divided into two groups. Experiment group was drenched with 2 mL ginsenoside Rh2 per mouse, equating to a dose 20 mg x kg(-1). Control group was drenched with 2 mL normal saline per mouse. The expression of JAM-1, JAM-2 in the lymphatics, blood vessels and tumours were observed by immunohistochemical staining. RESULT: The expression of JAM-1 on the cancer cells was significantly decreased in experiment group (IA 340.55) as compared with control group (IA 549.90, P<0.05). However, JAM-2 weakly expressed in both two groups. The density of blood vessels in which JAM-1, JAM-2 expressed showed 2.33 and 1.34 in control group, and 1.09 and 0.9 in experiment group respectively. Moreove, the density of lymph vessels were respectively 2.23 and 1.88 in control group compared with 0.99 and 0.79 in experiment group. The expression in blood vessels and lymph vessels in control group were significantly higher than those in experiment group, respectively (P<0.05). CONCLUSION: Ginsenoside Rh2 can affect the tumor growth, further angiogenesis and lymphangiogenesis by down-regulating JAM expression in tumor.

Morphologic features of lymphatic in periphery region of gastric carcinoma and colon carcinoma.

BACKGROUND & OBJECTIVE: Most of the studies on lymphatic metastasis mechanism of carcinoma are confined to distribution of lymphatics. This research was to observe distribution and morphologic features of the lymphatics in periphery region of carcinoma, and morphologic changes of lymphatic endothelia. METHODS: Specimens were obtained from 10 patients with gastric carcinoma and 10 patients with colon carcinoma; 20 mice models bearing colon carcinoma were established. Morphology of lymphatics and ultrastructure of lymphatic endothelia were observed under microscope. Number density and volume density of lymphatics in periphery region of carcinoma and normal region were measured using computer image analysis system; open rate and destructive rate of lymphatics were calculated. RESULTS: The lymphatics in periphery region of carcinoma were dilated; their walls were disintegrated. Lymphatic endothelia were dissolved and destroyed into broken fragments; the organellae showed pathologic changes. Number density and volume density of lymphatics were significantly higher in periphery region of colon carcinoma than in normal region [(10.2+/-1.7)/mm(2) vs. (5.1+/-0.8)/mm(2), P < 0.05û (1.5+/-0.2)% vs. (0.7+/-0.0)%, P < 0.05], and were significantly higher in periphery region of gastric carcinoma than in normal region [(8.0+/-0.9)/mm(2) vs. (3.4+/-0.6)/mm(2), P < 0.01; (1.6+/-0.3)% vs. (0.8+/-0.2)%, P < 0.05]. Open rate of lymphatics was significantly higher in periphery regions of mice model colon carcinoma, human gastric carcinoma, and colon carcinoma than in relevant normal regions (22.2% vs. 7.8%, 35.0% vs. 8.0%, and 25.8% vs. 5.0%, P < 0.05). Destructive rate of lymphatics was significantly higher in periphery regions of mice model colon carcinoma, and human gastric carcinoma than in relevant normal regions (20.1% vs. 0, and 35.3% vs. 2.0%, P < 0.05). CONCLUSION: Compare with the lymphatics in normal tissue, the lymphatics in periphery region of carcinoma tissue are dilated with disintegrated walls; the lymphatic endothelia are destroyed; the density of the lymphatics is increased.