黑龙江省三江平原丹顶鹤的数量分布

在地面调查的基础上,我们使用Y-11轻型飞机对黑龙江省三江平原地区的丹顶鹤的数量分布近行了调查,调查时飞行高度80米,航速140公里/小时,续航里程共3748公里。调查结果表明,丹顶鹤在三江平原主要分布在8个地区,其中嘟噜河下游、洪河自然保护区、七星河流域和兴凯湖低地是主要繁殖地,总数量共309只。     

刺激兔迷走神经引起的压抑心室纤颤作用

单个期前刺激引起急性缺血心脏能终止的心室纤颤。电刺激左侧颈迷走神经外周端可以缩短心室纤颤的持续时间。静脉注射β受体阻滞剂心得安后,刺激迷走神经对心室纤颤的作用消失。实验表示增加迷走神经的紧张性可能对终止室颤起有益作用。     

麻黄碱抑制小鼠输精管电场刺激致收缩的机制

麻黄碱(10 nmol/L~(-0.1) mmol/L)对电场刺激所致输精管收缩的浓度依赖性抑制作用可被育亨宾(0.1 μmol/L)减弱。去甲肾上腺素(0.1 nmol/L~(-10)μmol/L )和酪胺(0.1 μmol/L~(-0.1) mmol/L)也有类似麻黄碱的作用,去氧肾上腺素则缺乏此种作用。利血平处理和可卡因(10 μmol/L)可减弱麻黄碱和酪胺的抑制效应,但能增敏去甲肾上腺素的作用。高 Ca~( )和4-氨基吡啶(50 μmol/L)明显减弱甚至取消麻黄碱对电场刺激的抑制效应。以上结果提示麻黄碱抑制电场刺激所引起的输精管收缩。至少部分通过促进神经末梢释放去甲肾上腺素间接作用,后者激动突触前α_2-肾上腺素受体,从而抑制去甲肾上腺素的进一步释放。麻黄碱和其释放的去甲肾上腺素的作用,又可能与阻遏 Ca~( )内流有关。     

小麦颖果果皮绿色层内同化物的合成与分配

小麦幼嫩颖果中,果皮内侧发育出由内表皮与亚表皮组成的一薄层绿色组织。显微与亚显微结构观察表明,虽绿色层只接受到自然光照的1/4～1/8,叶绿体仍能正常发育,叶绿素含量与叶绿体数量均高出旗叶。大量胞间连丝联接相邻的绿色细胞,并在一定时期形成开放的胞间通道,显然有利于同化物的快速胞间运输。离体颖果饲喂~14CO_2试验证明,新合成的同化物从绿色细胞输向胚珠。绿色层产生的同化物可能通过合点端的珠心进入胚乳或通过珠孔直接汇聚到胚珠和分化中的原胚。     

中药玄参的化学成分

从中药玄参（ＳｃｒｏｐｈｕｌａｒｉａｎｉｎｇｐｏｅｎｓｉｓＨｅｍｓｌ．）中分离得到１个新化合物：４－Ｏ－（对甲氧基肉桂酰基）－α－Ｌ－鼠李糖［４－Ｏ－（ｐ－ｍｅｔｈｏｘｙｃｉｎｎａｍｏｙｌ）－α－Ｌ－ｒｈａｍｎｏｐｙｒａｎｏｓｅ］;同时还分离到４个已知的环烯醚萜甙：爪钧草甙（ｈａｒｐａｇｉｄｅ）,爪钩草酯甙（ｈａｒｐａｇｏｓｉｄｅ）,Ｏ－甲基梓醇（Ｏ－ｍｅｔｈｙｌｃａｔａｌｐｏｌ）,士可玄参甙Ａ（ｓｃｒｏｐｏｌｉｏｓｉｄｅＡ）和１个已知的苯丙素甙：安格洛甙Ｃ（ａｎｇｏｒｏｓｉｄｅＣ）。新化合物的结构通过化学降解和光谱分析得到证明。     

Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan province of China

mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km² in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal origins, as suggested by fossil and literature records. We think the population of horses is an amazing seed-resource pool of horses and hence deserves to be paid more attention from the view of conservation genetics. However, it is also remarkable that we did not find any typical mtDNA genetic markers which would discriminate between short horses and common domestic horses.     

湿螨属四新种记述及中华湿螨再记述：（蜱螨亚纲：湿螨科）

本文记述湿螨属水螨四种新种：郭氏湿螨Ｈｙｇｒｏｂａｔｅｓ ｇｏｕｓｉ ｓｐ．ｎｏｖ．,贵州湿螨Ｈ．ｇｕｉａｈｏｕｅｎｓｉｓ ｓｐ．ｎｏｖ．,墨缘湿螨Ｈ．ａｔｒｏｖｉｒｅｎｓ ｓｐ．ｎｏｖ．和兴义湿螨Ｈ．ｘｉｎｙｉｅｎｓｉｓ ｓｐ．ｎｏｖ．．文中扼述了它们与近似种的区别。另外。还对中华湿螨Ｈ．ｓｉｎｅｎｓｉｓ Ｕｃｈｉｄｅ Ｉｍａｍｕｒａ作了再描述。     

埃及血吸虫毛蚴表皮板的观察

埃及血吸虫毛蚴表皮板共有4排,各排数目为6:9:4:3。除第1排之外,其他各排的表皮板均由无纤毛的嵴所分隔,在第1与第2排之间的环嵴中,除第1排各板底边中央小凹处各有1感受器外,尚可见4对感受器。第2与第3排的环嵴内可见16—20个感受器。此外,于体之两侧第3排表皮板间各见1个排泄孔。顶突似六边形,于其两侧各有1个侧腺开口,其内侧可见14个感受器。本文在讨论中与前人对本虫毛蚴表皮板的描述做了简单比较。     

The inhibitory effect of transthyretin gene on growth of human hepatoma cells

Transthyretin(TTR) gene was highly expressed in normal liver and it has been found to be deleted in part of DNA samples from human hepatic cancer.Its mRNA expression was suppressed in most hepatoma samples.In order to study the biological effect of TTR gene on the growth of hepatoma cells,a recombinant vector containing TTR cDNA was constructed by pCMV,then it was transfected into hepatoma cell lines SMMC-7721 and Q3.It has been demonstrated that the inhibition of growth rate of TTR cDNA transfected hepatoma cells was about 50% in strength compared with that of the control.This inhibition was further enhanced when the transfected hepatoma cells were treated with all-trans retinoic acid.Hepatoma cells of cell lines PLC/PRF/5,SMMC-7721 and Q3 as well as hepatoma cells SMMC-7721 transfected with pCMV or pCMV-TTR were analyzed for TTR expression by Northern hybridization.The low level of TTR expression was found in both hepatoma cell lines and in SMMC-7721 cells transfected with pCMV alone.However,a remarkable TTR mRNA expression was observed in hepatoma SMMV-7721 cells transfected with pCMV-TTR.It seems possible that TTR gene might be a candidate of cancer suppressor gene for human hepatic cancer.