四川省鱼类寄生粘孢子虫两新种（粘孢子纲：双壳目）

本四川省鱼类寄生粘孢子虫两新种：寄生墨头鱼的宜宾两极虫,新种Ｍｙｘｉｄｉｕｍ ｙｉｂｉｎｅｎｓｅ ｓｐ．ｎｏｖ．和寄生鳙Ａｒｉｓｔｉｃｈｔｈｙｓ ｎｋｂｉｌｉｓ的鳙单尾虫,新种Ｕｎｉｃａｕｄａ ａｒｉｓｔｉｃｈｔｈｙｄｉｓ ｓｐ．ｎｏｖ。     

丁酸钠和pH值对离体蚕豆花药中小孢子有丝分裂的影响

含单核中后期至后期花粉的蚕豆离体花药,经过2mM丁酸钠24小时预处理后,再漂浮培养于pH5.8或7.0的液体培养基。以不经预处理的作为对照。结果如下: 1.培养后9天内,丁酸钠预处理和培养基pH值并不明显影响花粉退化百分率。2.培养初期,pH7.0显著促进小孢子不等分裂。3.丁酸钠预处理抑制培养初期的小孢子有丝分裂,而后又显著增加小孢子均等分裂百分率。4.丁酸钠预处理导致小孢子有丝分裂类型的趋向改变。本文还对丁酸钠导致有丝分裂类型趋向改变的可能原因,进行了讨论。     

家兔晶状体纤维的超微结构:纤维细胞的间隙连接

本文报道晶状体纤维细胞间间隙连接的形态结构。我们利用冰冻断裂技术,在不同部位的球-和-凹连结的头部以及在纤维细胞和纤维细胞之间都观察到间隙连接的存在。通过极其丰富的上述连接,可实现细胞间代谢物和离子的传递。作者认为:对正常晶状体纤维细胞之间的间隙连接的深入了解,将会为晶状体发病机制的研究提供新的线索。     

猫尾核头部前区对三叉神经尾端脊束核的抑制作用及其方式

在清醒麻痹状态下的55只猫上,观察了电刺激尾核头部前区(Cd)对三叉神经尾端脊束核(cST)中了齿槽神经(AI)伤害性刺激所诱发的放电的影响。刺激 Cd 可以抑制大多数 cST 神经元的伤害性反应,抑制持续约100—500ms。抑制时程可为静脉注射戊巴比妥钠和安定而延长,注射印防己毒素可使其缩短。马钱子素使抑制时程稍有延长。这些结果提示,Cd 对 cST神经元的抑制作用是通过突触前抑制的方式实现的。     

人工补充寄主卵对松林内卵蜂种群消长的影响

在不同生境的松林中,人工补充寄主卵都能提高寄生效果。但林地生境不同,寄生率有明显差异。在松阔混交林中补充寄主,其寄生率比对照提高5.5—16.2倍。植被稀疏的纯松林效果较差,补充的寄生率比对照提高3.0倍。 卵蜂种群消长随季节温度而变化,全年以5月中旬至6月下旬和9月中旬至10月中旬为两个寄生高峰。卵蜂种群与松毛虫种群的消长存在较明显的相依关系,卵蜂种群随着松毛虫种群的消长而消长。施药对卵蜂种群有较大影响,施药区比对照区的寄生率约降低一倍。在混交林中填充寄主卵,能促进卵蜂种群世代延续。在逐步改善林地生境的基础上,利用人工补充寄主,可以代替人工繁蜂放蜂。     

中国吻额蛛属一新种（蜘蛛目：皿蛛科：微蛛亚科）

本文描述了作者1986年采自湖北省神农架林区的吻额蛛属Aprifrontalia一新种:膨大吻额蛛,新种Aprifrontalia afflata sp.nov.。目前,除本新种外,世界仅报道过1种:Aprifrontalia mascula,本新种雄蛛最显著的特征是:其额向前突呈吻状,触肢胫节前端甚膨大。外雌器形成一斜向下方的突起。模式标本保存于白求恩医科大学生物教研室。     

Conformational changes of recombinant human granulocyte-colony stimulating factor induced bypH and guanidine hydrochloride

Fluorescence and circular dichroism were used to follow thepH-dependent conformational changes of granulocyte colony stimulating factor (G-CSF). Tryptophan fluorescence of the spectra monitored at 344 nm, or after deconvolution of the emission spectra, at 345 nm, showed a decrease in intensity on going frompH 7 to 4, with a midtransitionpH of 5.8. On the other hand, tyrosine fluorescence measured either by the ratio of intensity at 308 nm to that at 344 nm, or by the fluorescence intensity at 303 nm after deconvolution of the spectra, increased in intensity as thepH was changed from 6 to 2.5, with a midtransitionpH of 4.5. Near UV circular dichroic spectra also showed changes betweenpH 7.5 and 4.5, which correlated with the transition monitored by the tryptophan fluorescence. The guanidine hydrochloride-induced conformational changes of G-CSF at fivepH values from 2.5 to 7.5 were also studied. Circular dichroic and fluorescence spectra revealed minor conformational changes by the addition of 1 or 2 M guanidine HCl at allpH values examined, while the major conformational transition occurred between 2 and 4 M guanidine hydrochloride. The secondary structure of the protein was most stable betweenpH 3.3 and 4.5. The guanidine HCl-induced denaturation of G-CSF involved more than a two-state transition, with detectable intermediate(s) present, and the structure of the intermediate(s) appeared to depend on thepH used. These results are consistent with thepH dependence of the structure described above, and demonstrate the complex conformational properties of G-CSF.