人体小卫星DNA探针的制备

根据人体小卫星DNA核心顺序,化学合成长23碱基寡核苷酸探针,筛选人体基因组文库,旨在获得能用作遗传分析探针的小卫星顺序。结果得到15个含小卫星的阳性重组子。随机取其一(C_(35.9))作探针,试做群体分析。所有个体均可检出多条杂交带。其中某些带具有多态性。在一定检测条件下,检出的DNA图谱在有限的个体内具有个体特异性。结果表明筛选文库得到的小卫星顺序可用于小卫星多态性的检测。其它小卫星探针的筛选和应用性研究正在进行。     

Effects of traces of rare earth elements on the protozoanBlepherisma and on mice

The growth of the protozoanBlepherisma is stimulated by Lanthanum (La) at concentrations as low as 0.32 ppm. In mice Yttrium (Y) and Ytterbium (Yb) are absorbed, accumulated, and metabolized. Both rare earth elements (RE) exhibit a high affinity for teeth and bones, accumulation occurs and metabolism is slow. In the livers of RE-exposed mice, concentrations are variable. The liver is apparently capable of absorbing and discharging RE in a manner depending on metabolic activity. The main route of discharge for ingested REs is the alimentary canal. Exposure of pregnant mice to RE leads to rapid placental transfer of RE; 14.1% of the total amount of RE administered was detected in newborn mice. Young, developing organisms appear to be especially susceptible to RE accumulation.     

Microtubule and microfilament distribution and tubulin content in the cell cycle of Indian muntjac cells

Using DAPI, rabbit antitubulin antibody, FITC-labeled goat anti-rabbit IgG, and TRITC-phalloidin to stain individual cells, the microspectrophotometric analysis showed that three markers that represent the nucleus, microtubules (MT), and microfilaments (MF), respectively, could be recognized in individual cells without interference. The phase of the cell cycle was determined by DNA content. We found that in Indian muntjac (IM) cells, the amount of tubulin in G2 and M phases was about twice as much as that in G1 phase. In G2 cells, the cytoplasmic microtubule complex (CMTC) became denser than in G1 cells. The cytoplasmic MT extent in basically the same orientation as MF bundles in interphase. The regions where the MT is denser also have a denser MF distribution.     

异细胞质八倍体小黑麦的获得及其细胞遗传

改变小黑麦细胞质有可能增加减数分裂的稳定性,提高小黑麦的结实率与籽粒饱满度。作者以不同细胞质的“中国春”小麦与黑麦杂交,F_1幼苗用秋水仙素加倍获得双二倍体、或以八倍体小黑麦为父本与F_1杂交,获得异细胞质八倍体小黑麦(Triticale 8x)8个品系。实验结果表明:细胞质不同的“中国春”小麦与黑麦杂交结实率差异显著,出苗率亦不同,F_1株型多为两亲的中间型,花药不开裂,个别组合出现雄蕊雌化现象,有的组合表现生长弱性,减数分裂中期Ⅰ常出现1至数个末端交叉的棒状二价体,其数量在不同组合间差异显著,表明异细胞质对染色体配对有影响。D类细胞质对改进八倍体小黑麦的结实率可能有一定的作用。     

电离辐射后大鼠离体胰腺腺泡淀粉酶释放及M受体数量变化

我们曾观察到大鼠经γ-射线照射后胰淀粉酶活性降低和分泌减少[1],为进一步探讨照射后胰酶分泌减少的机制,本研究制备出分散的大鼠胰腺腺泡悬液并以不同浓度的~3H-二苯羟乙酸-3-喹咛环酯(~3Hquinuclidinyll benzilatc,简称~3H-QNB)进行M受体结合测定,同时观察胆碱能介质氨甲酰胆碱刺激腺泡所引起的淀粉酶释放反应。结果表明,γ-射线10Gy照射后3天,大鼠分散的胰腺腺泡在氨甲酰胆碱刺激时淀粉酶释放量减少到对照的50％,腺泡M受体与~3H-QNB最大结合量(Bmax)减少到对照的38％,伋M受体与~3H-QNB结合的解离常数(K_D)无改变,说明胰腺腺泡细胞M受体数量的减少可能是照射后胰腺腺泡分泌淀粉酶减少的原因之一。     

Interaction of opioid peptides and other drugs with multiple kappa receptors in rat and human brain. Evidence for species differences.

Previous experiments resolved four kappa binding sites in guinea pig brain termed kappa 1a, kappa 1b, and kappa 2b. The present study was undertaken to examine the occurrence of kappa receptor subtypes in rat and human brain. [3H]U69,593 and [3H]bremazocine were used to label kappa 1 and kappa 2 binding sites, respectively, present in brain membranes depleted of mu and delta binding sites by pretreatment with the irreversible ligands, BIT and FIT. Low levels of [3H]U69,593 binding precluded a detailed quantitative study of kappa 1 binding sites in these species. Quantitative examination of [3H]bremazocine binding resolved two kappa 2 binding sites in both rat and human brain whose ligand selectivity patterns differed from that of the guinea pig. These observations suggest that there may be considerable variation in the ligand recognition site of kappa receptor subtypes among mammalian species.     

人酸性成纤维细胞生长因子神经营养作用的初步研究

本实验研究了人酸性成纤维细胞生长因子(haFGF)的体外神经营养作用。结果表明,haFGF在体外能明显促进鸡胚(E-8)脊髓组织神经突起的生长,并能明显改变新生大鼠脑星形胶质细胞的形态,使扁平、多角形紧密联接的细胞转化为具有纤维样突起的胶质细胞,同时对胶质细胞DNA合成也有一定促进作用。实验还证明,haFGF可增加体外培养新生大鼠海马神经元的存活,且大大增加神经元胞体体积及突起长度。