Genetic characterization and authentication of Dimocarpus longan Lour. using an improved RAPD technique

Dimocarpus longan Lour. is an edible and traditional herb in China, commonly referred to as longon. An improved randomly amplified polymorphic DNA (RAPD) protocol was here developed in order to determine the geographical origins of D. longan samples collected from 5 provinces in the southern and southwestern areas of China, including Sichuan, Hainan, Fujian, Guangdong, and Guangxi. Generally, the improved RAPD method generated good fingerprinting of the 5 samples using the selected 17 primers. In particular, primers SBS-A5, SBS-A13, SBS-I9, SBS-I20, SBS-M1, and SBS-Q12 produced distinguishable bands that clearly separated all 5 cultivars, suggesting that there are variations in RAPD genetic sites among the samples. The similarity index ranged from 0.69 to 0.76. The Sichuan and Hainan clades clustered together with a 0.73 similarity index. The Guangxi and Fujian clades clustered together with a 0.76 similarity index, and they formed the sister clade to the Sichuan/Hainan clade with a 0.71 similarity index. The Guangdong clade was in a basal polytomy with a 0.70 similarity index. Based on the abundant DNA polymorphisms, these longan accessions are distinguishable using our improved RAPD technique. Therefore, RAPD analysis is an effective technique in distinguishing the geographical origins of D. longan. Moreover, the improved method could also be employed for a variety of applications including genetic diversity and fingerprinting analyses.

[An animal experiment and clinical investigation on the protective effect of selenium on the microcirculation induced by free radical damaged RBCs]

Fluorescent labeling image analysis was used to evaluate the changes in cerebral arteriole and veinlet diameters (D), circulation velocities (FV) and permeability (VP) in rats; while in clinics, a laser-doppler device was used for assessing changes of skins and muscles microcirculation. The results show that in control rats, equal volume perfusion of free radical damaged RBCs resulted in decreases of D and FV significantly but VP was increased, whereas in the case when free radical damaged RBCs were perfused together with selenium, no disturbances in the D and VP were observed with FV even improved. In the human control group, either average skin microcirculative perfusions (ASMP) at 25 degrees C or maximal skin microcirculative perfusions (MSMP) at 42 degrees C were evidently decreased during myocardial ischemia/reperfusion period, while ASMP at 24th hour of post-surgery was kept reducing. At the same time, the changes in muscles microcirculative perfusions (MMP) tended to be similar to the skin, but overloaded than the pre-surgery levels at 24th hour of post-surgery period. In the selenium group before surgery, the ratio of MSMP to ASMP was obviously increased than the control group (3.95 in Se group vs 1.74 in control group, P < 0.05), but did not have significantly differences in ASMP, MSMP and MMP between the two groups during surgery period. RBC deformabilities were not changed. At 24th hour post-surgery, the ASMP were almost restored to pre-surgery levels. However, MMP were still lower than the pre-surgery levels.

CONCLUSIONS

(1) free radical damaged RBC perfusion leads to damage of microcirculation; (2) selenium is highly efficient in protecting microcirculation from free radical damaged RBC disturbance; and (3) Oral administration of selenium may improve pre-surgery maximal skin microcirculative perfusion and promote recovery of the worsened skin microcirculation in addition to prevent the occurrence of RBC deformability.

Cerebral microcirculatory disturbances of stroke prone spontaneously hypertensive rats with acute stroke and mechanism of treatment

Cerebral microcirculatory behavior of stroke prone spontaneously hypertensive rats (SHRSP) suffering from acute stroke (WKY as control group) was studied with laser Doppler flowmetry in vivo. The pharmacological effects of Dextran 40, nimodipine and the combined use of both drugs (40:1 volume ratio) on cerebral microvessels were measured. The results of the experiment have shown that SHRSP had a serious cerebral microcirculatory disturbance when the acute stroke occurred. Both Dextran 40 and nimodipine could improve the cerebral microcirculatory disturbance, but the combined usage presented far more satisfactory effects. Hopefully it will decrease the mortality of patients with acute stroke.

[Angiogenesis induced by SP2/0 and HeLa tumor cells]

Cheek pouches of Syrian golden hamsters and transparent access chambers of BALB/C mice were implanted with SP2/0 and HeLa tumor cells separately. Observation was done by continual photo and video from D 1 through the D 10 after implantation. It was found by the development of angiogenesis and the density of microvessels that both kinds of tumor cells could induce angiogenesis. On D 2 after implantation, there appeared leakage and hemorrhage from the microvessels near the tumor cells. On D 3 and D 4, there was an increased density of new capillaries which formed a very fine, tortuous and basketlike vascular plexus of irregular diameter. Most of the new microvessels came from the venules on the edge of the implant mass and they grew toward the tumor cells to penetrate the tumor tissue on D 4 to D 5. On D 7, the density of new microvessels reached the maximum and they began to extend outside the tumor which was surrounded by dense new capillaries. Compound 36 has been proved an effective substance against some tumors in clinical applications in this country. Also proved by our experiments, a drug effective in inhibition of angiogenesis induced by SP2/0 tumor cells.

The study of spectra and X-ray crystal structure of a novel bionics insecticide--(CH3)2NHCH(CH2S2O3)2Na X H2O

IR and NMR spectra of novel bionics insecticide--C5NS4O6H12Na X H2O have been studied. The molecular and crystal structures of the compound also have been determined. The compound crystallizes in the monoclinic space group C5(2)h-P21/n with a = 8.0972(9)A, b = 16.262(4)A, c = 10.370(3)A, beta = 94.26(2)degrees and z = 4. The result shows that N atom in this compound captures a proton to form HN+ group, Na+ is in statistical disorder. Therefore, the structural formula of the compound is (CH3)2HN+-CH(CH2S2O3-)2 X 1/2(Na+)2 X H2O.