The Anti-HIV Actions of 7-and 10-Substituted Camptothecins

Camptothecin (CPT), a traditional anti-tumor drug, has been shown to possess anti-HIV-1 activity. To increase the antiviral potency, the anti-HIV activities of two CPT derivatives, 10-hydroxy-CPT and 7-hydroxymethyl-CPT, were evaluated in vitro. The therapy index (TI) of CPT, 10-hydroxy-CPT and 7-hydroxymethyl-CPT against HIV-1(IIIB) in C8166 were 24.2, 4.2 and 198.1, and against clinical isolated strain HIV-1(KM018) in PBMC were 10.3, 3.5 and 66.0, respectively. While the TI of CPT, 10-hydroxy-CPT and 7-hydroxymethyl-CPT against HIV-2(CBL-20) were 34.5, 10.7 and 317.0, respectively, and the TI of the three compounds against HIV-2(ROD) showed the similar values. However, when the antiviral mechanisms were considered, we found there was no inhibition of 7-hydroxymethyl-CPT on viral cell-to-cell transmission, and was no inhibition on reverse transcriptase, protease or integrase in cell-free systems. 7-Hydroxymethyl-CPT showed no selective killing of chronically infected cells after 3 days of incubation. In conclusion, 7-hydroxymethyl-CPT showed more potent anti-HIV activity, while 10-hydroxy-CPT had less efficient activity, compared with the parent CPT. Though the antiviral mechanisms remain to be further elucidated; the modification of -OH residues at C-7 of CPT could enhance the antiviral activity, while of -OH residues at C-10 of CPT had decreased the antiviral activity, which provides the preliminary modification strategy for anti-viral activities enhancement of this compound.

用于研究快速扫视对瞳孔光反射调制作用的新方法

瞳孔与光反射系统和快速扫视系统在解剖学和功能上都有着紧密联系，但是快速扫视系统对瞳孔的光反射系统是否有调制作用尚无报道。研究这两个系统间的调制作用，必须了解光刺激不均匀和近反应对瞳孔直径变化是否有影响。该研究以人为被试，设计了一种全新的实验方法，研究光刺激不均匀和近反应对瞳孔直径变化的影响。实验方法：将被试的一只眼用密闭的眼罩罩住给予脉冲光刺激，刺激由位于眼罩内全视野范围水平排列的一排发光二极(lightemitting diodes，LEDs)给出，被试的另一只眼用来记录眼动和瞳孔直径的变化，研究水平方向的快速扫视对瞳孔对光反射时瞳孔直径变化的影响。实验结果：比较被试注视视野内不同位置的瞳孔对光反射相对收缩率无显著差异（P=0.148, 非配对样本t 检验）。结论：该方法消除了光刺激不均匀和近反应对瞳孔直径变化的影响，可用于研究快速扫视系统对瞳孔光反射系统间的调制作用。

Molecular phylogeny of the yuhinas (Sylviidae : Yuhina): a paraphyletic group of babblers including Zosterops and Philippine Stachyris

Mitochondrial sequences (2,379 bp) from cytochrome b, ND3, 12s and 16s rRNA were analyzed in order to reconstruct the phylogenetic relationships within the yuhinas (Yuhina), including the chestnut-faced babbler Stachyris whiteheadi which is endemic to the

云南短翼蚱科一新属新种(直翅目：蚱总科)

：报道了云南短翼蚱科一新属和一新种：冠顶蚱C．a／yptraeus新属，勐腊冠顶蚱C．meng／aens／5新种。

云南高黎贡山白颌大角蟾的核型、C-带及Ag-NORs的研究

比较了云南高黎贡山地区的贡山独龙江和腾冲大蒿坪白颌大角蟾（Megophryslateralis）两个地理种群的核型、C-带和Ag-NORs结果表明，两个地理种群在核型和带型上都有差异两个地理种群的核型均为2n＝26，NF＝52染色体形态差异不明显，而次缢痕的位置完全不同，贡山独龙江标本的次缢痕位于No．2的长臂上近着丝点处，腾冲标本的次缢痕位于No．5的短臂上近着丝点的部位在腾冲标本中发现一雄性个体中有一条额外的染色体，可能是B染色体两地标本的C-带差异不太显著，贡山独龙江标本的C-带相对较为显著．贡山独龙江标本的Ag-NORs位于No．2长臂近着丝点处，与次缢痕的部位对应，两条同源染色体上大小有显著差异．腾冲标本的Ag-NORs位于No．5短臂上近着丝点处，与次缢痕的部位对应依据核型和带型的比较，对白颌大角蟾的分类和进化问题进行了讨论。

基于从头算的缬氨酸两性离子和水分子的相互作用势

首先用从头算方法计算缬氨酸两性离子同处于160种不同位置的水分子的相互作用能, 计算 时采用最小基组并进行了基组重叠修正, 最后对计算得的相互作用能Slater-Kirkwood 公式作色散能修正; 然后进行势函数的拟合, 即舍弃12个相互作用能大于5Kcal/mole或原子间距离小于1.68A的布点, 对其余148个布点进行拟合。拟合结果的标准偏差为SD=0.48Kcal/mole。图1表3参13

进化中的选择原理

该文简要介绍了在过去几十年中非平衡统计物理研究有序现象的新概念及其在探讨进化问题中的应用和意义。

中国鲤科鱼类新纪录——爪哇四须鲃

2001年7月于云南省西双版纳州勐腊县罗梭江(澜沧江的支流)中采集到2尾鱼类标本, 经鉴定为中国鲤科鱼类四须鲃属 Barbodes 的一个新纪录——爪哇四须鲃 Barbodesgonionotus. 该新纪录与本属其他种的显著区别为其臀鳍分枝鳍条有 6～7根, 而其他种有5根。

The in vivo synaptic plasticity mechanism of EGb 761-induced enhancement of spatial learning and memory in aged rats

1 It has not been uniform to date that the Ginkgo biloba extracts enhance cognitive function in aged animals, and the mechanisms of action remain difficult to elucidate. In this study, the Morris water maze task and electrophysiological methods were used