姬松茸与双孢蘑菇不同菌株的RAPD扩增研究

以4个姬松茸菌株和2个双孢蘑菇菌株为材料，用20个随机引物对它们进行RAPD扩增，通过对供试菌株遗传相似系数的估算和系统聚类分析，构建姬松茸和双孢蘑菇遗传相关树状聚类图谱，结果表明，进行RAPD扩增的20个随机引物中，有12个能产生三种带型，当遗传相似系数升至0.8713时，这6个菌株被分为3类，第一类为菌株18和26，第二类为菌株13和12，第三类为菌株33和45。     

黄瓜无毛突变体的生理特性研究

 黄瓜无毛突变体与普通黄瓜相比, 幼苗的各种性状均没有明显变化; 成株矮化明显, 雌花数降低, 产量明显下降, 但雌花节率没有明显变化, 蒸腾速率、气孔导度较高, 其他光合作用指标没有明显变化。遗传研究表明, 无毛性状是由一对核基因控制的隐性性状。     

粉蕉、大蕉和龙牙蕉的AFLP分类研究

 应用AFLP 技术, 对32 个粉蕉、大蕉、龙牙蕉品种进行了遗传多样性分析及分类研究。在分子水平上, 可将供试品种聚为6 个独立群体, 其中包括3 个分别由单一品种组成的群体(群体Ⅳ: 酸大蕉;群体Ⅴ: 孟变; 群体Ⅵ: 千旁培) ; 可以将群体Ⅰ (大蕉) 和群体Ⅱ (粉蕉) 分别划分为3 个品种群, 将群体Ⅲ (龙牙蕉) 划分为2个品种群。参照Simmonds 的形态学分类方法, 研究结果显示粉蕉、大蕉以及龙牙蕉各个品种之间存在丰富的遗传多样性, 将其划分为AAB 或ABB 等类型, 不能反映品种间的亲缘关系; 粉蕉与大蕉两个类群之间遗传距离差异明显, 将其简单的归为ABB 类型是不妥当的。     

果树种质资源离体保存研究进展

综述了国内外果树种质离体保存方面的研究进展,简单介绍了种子保存,常规的细胞、组织和器官保存方法。超低温保存是一项长期稳定保存种质的方法,能减慢细胞代谢和完全抑制生长,概述了超低温保存的原理、技术要点和主要优点,以及影响超低温保存的因素:包括植物材料的性质、预处理、冰冻保护剂种类、降温方法、解冻方法以及解冻后处理等,并对今后果树种质保存提出了一些建议。     

Changes of K+ channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity

AIM:To study the changes of K⁺ channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity. METHODS:Auditory brainstem responses (ABR) and whole-cell patch clamp techniques were used.RESULTS:(1) The body weight of guinea pigs with streptomycin ototoxicity decreased significantly; (2) The ABR threshold markedly increased in streptomycin group (Ⅱ,Ⅲ);(3)The number of dissociated outer hair cells of guinea pigs (Ⅱ,Ⅲ) was lower than that of control (Ⅰ); (4) Streptomycin decreased the Ca²⁺-sensitive K⁺ currents and delayed outward K⁺ currents distinctly; (5) There was no significant difference of K⁺ currents between Ⅰ and Ⅱ/Ⅲ. CONCLUSION:These results suggest that the inhibition of K⁺ channels is the basis of streptomycin ototoxicity, but not the direct reason for cell death.     

Role of angiotensin II and angiotensin II receptors in vascular smooth muscle cells migration

AIM:To determine the effects of Angiotensin II(AngII) on migration of rat smooth muscle cells and to investigate the mechanisms underlying Ang II action in the development of injured vascular disease. METHODS:VSMCs isolated from aortic media of Wistar rats and cultured by the modified explant method were adopted. In prersence and absence of AngII, the expression of AngII receptor and reorganization of the actin cytoskeleton of VSMCs were studied by immunocytochemistry technique, fluorocytochemistry technique. The migration assays were performed by a modified Boyden's chamber. And the effects of AT₁R antagonist (CV-11974), AT₂R antagonist (PD123319) on aforementioned target were studied.RESULTS:VSMCs migration was stimulated by addition of AngII. The dynamic reorganization of actin cytoskeleton may be an important mechanism by which AngII facilitates VSMC motility. The expression of AT₁R in VSMCs can be upregulated after treatment with AngII initially, then decreased gradually. The expression of AT₁R was downregulated by AT₁R antagonist. The effect of AngII on VSMCs migration was mediated by AT₁R, while AT₂R had no significant effect.CONCLUSION:The dynamic reorganization of actin cytoskeleton is required for AngII-induced VSMC migration, and this effect is mediated by AT₁R .     

Effects of external counterpulsation on renin-angiotensin system and hemodynamics in dogs with myocardial ischemia

AIM:To examine the effect of external counterpulsation(ECP) on renin-angiotensin system(RAS) and hemodynamics in dogs with myocardial ischemia and their relationship. METHODS:Acute myocardial ischemia was induced by occluding the left anterior descending of the dogs. The local renin activity, angiotensin Ⅱ(AngⅡ) level, angiotension-converting enzyme(ACE) activity were tested by biochemical methods and hemodynamics was recorded by a 8-channel physiological recorder.RESULTS:Ischemia could actiivate renin,ACE and AngⅡ in cardiovasculature and ECP reduced them except for renin in ischemic myocardium. Ischemia also could activate RAS in lung and kidney, which play an important role on circulating RAS, and ECP reduced them. Furthermore, ECP could improve hemodynamics and there existed a close relationship between local AngⅡlevel and hemodynamics. CONCLUSION:ECP can reduce local RAS and improve hemodynamics in dogs with myocardial ischemia, which might be one of mechanisms underlying the protective effect of ECP on ischemic myocardium.     

Effect of Jiawei Sini Decoction on glucocorticoid receptor in thymocytes of chronic psychological stress rats

AIM: To observe the effect of Jiawei Sini Decoction (JWSND) on glucocorticoid receptor (GCR) in thymocytes of chronic psychological stress rats. METHODS: The rats were randomly divided into 4 groups, control group (C), model group (M), group treated by JWSND C₁, group treated by ginsenosides C₂. The number of thymocyte GCR sites and the GCR nuclear thanslocation rate were detected by radioimmunoassay. RESULTS: Compared with the control group, in the model group, the thymocyte weight index lowered significantly ( P<0.05 ), and the GCR nuclear thanslocation rate was increased significantly ( P<0.01 ), but the number of thymocyte GCR sites was unchanged. Compared with the model group, thymus gland weight indexes of C₁ and C₂ were increased significantly ( P<0.05 ), while the GCR nuclear thanslocation rate lowered significantly ( P<0.01 ). Moreover, no significant difference was found in all indexes between C₁ and control group. CONCLUSION: The inhibitory effect of glucocorticoid on the thymus could be significantly reversed by JWSND via suppressing the thanslocation of GCR from cytoplasm to nucleus in chronic psychological stress rats.     

Effects of platelet-derived growth factor on DNA and collagen protein synthesis in human vascular fibroblasts

AIM: To investigate the effects of platelet-derived growth factor on DNA and collagen protein synthesis in human vascular fibroblasts. METHODS: In the present experiment, the human vascular fibroblasts were cultured and effects of platelet-derived growth factor-BB on DNA and collagen protein synthesis in human vascular fibroblasts were observed by using [³H]-TdR incorporation and [³H]-proline incorporation in vitro. RESULTS: Platelet-derived growth factor-BB significantly promoted NDA synthesis and collagen protein synthesis of quiescent human vascular fibroblasts, with a maximal response at a concentration of 30μg·L^-1at 24 h and 36 h, respectively. CONCLUSION: Platelet-derived growth factor-BB promotes DNA and collagen protein synthesis in cultured human vascular fibroblasts.     

松毛虫CPV、B.t.林间防治第一代马尾松毛虫试验初报

用松毛虫CPV和B.t.进行喷雾防治马尾松毛虫试验，试验表阴：药后18d两种生物药剂的防治效果均在70%以上，B.t.达86．98％，CPV与B.t.的混合使用防效达85．04％。