Effect of the level of ATP and of the state of spectrin on osmotic properties of bovine erythrocytes

The effect of the intracellular level of ATP and of the state of spectrin on the critical cell volume of bovine erythrocyte was studied. The state of spectrin was changed by thermal denaturation, which for the bovine red cell took place at similar temperature as for the human erythrocyte. The increase of the ATP level and the spectrin denaturation increased the critical cell volume, while metabolic starvation decreased it. The changes of the ATP level did not influence the critical volume after the denaturation of spectrin. The results suggest that the ATP-dependent effect on the critical cell volume was caused by an alteration of the membrane extensibility due to the change of the membrane skeleton-lipid bilayer interaction(s).     

榉树叶片解剖构造和叶肉细胞超微结构的观察

对取自不同季节的榉树(Zelkova schneideriana hand.-Mazz.)叶的解剖构造和叶肉细胞超微结构进行了观察。榉树叶表面被密集锥状单细胞毛,幼叶则还有头状腺毛。气孔多分布在叶下表面,为不规则型。上表皮细胞外壁具有明显的角质层加厚,局部上表皮由2层细胞组成。叶肉细胞分化为栅栏组织和海绵组织;栅栏组织1—2层细胞;海绵组织发达,常与气孔相连。叶肉有含晶细胞存在。叶脉的维管束鞘明显,是厚壁细胞。成熟叶肉细胞细胞器丰富,有8-9个周壁叶绿体,为巨大的长椭圆形,基粒片层清晰,有淀粉粒,少量脂滴。叶片开始转变颜色时,叶绿体由长椭圆形变得趋于圆形;基粒片层逐渐变得杂乱至模糊不清;脂滴数目增多。秋季叶色不同的榉树叶片解剖构造存在一定差异。     

铜锈环棱螺肝脏的显微与超微结构观察

应用组织切片、光学显微镜及透射电子显微镜技术,对铜锈环棱螺肝脏进行观察研究。结果表明,铜锈环棱螺肝脏为复管泡状腺,由许多肝小叶组成,每个肝小叶管壁由单层上皮细胞构成,分3种细胞：消化细胞、排泄细胞、钙细胞。光镜显示,肝小叶多球形或近球形,横切面管腔呈星射状裂隙,纵切面可见上皮细胞呈柱状,核靠近基膜,上皮细胞极性明显。消化细胞构成腺上皮的主体,染色较淡。排泄细胞和钙细胞染色较深。肝腺管之间有不规则圆形的网状细胞,结缔组织填充在肝小叶之间及小叶与导管之间。电镜显示,消化细胞和排泄细胞顶端都具微绒毛,消化细胞主要特征为具有溶酶体囊泡系统,参与细胞内消化过程。排泄细胞中粗面内质网、线粒体等细胞器含量丰富,细胞内还散布着大量脂滴。钙细胞锥体形,主要特征为细胞内具钙粒子,也含有大量细胞器。     

Molecular-genetic basis of regulation of the synthesis of individual types of hemoglobin

The data on the control of ontogenetic hemoglobin type synthesis were analyzed in normal and pathological human and animal organisms. The assumption is made that such control depends on the level of erythroid cell differentiation and erythropoetic factors activity. The latters act as a trigger in switching of qualitative hemoglobin production.     

平疣桑椹石磺精子结构观察

通过电光学显微镜和透射电子显微镜观察了平疣桑椹石磺精子的形态及其超微结构。平疣桑椹石磺成熟精子属于进化型,由头部、中段和末段组成。头部由顶体和精核构成,顶体长约0.7μm,呈细奶嘴状,内含物分布均匀,电子密度稍低于细胞核。顶体基部与精核前端紧密相连,无间隙。精核长约3.8μm,宽约1.0μm,核质高度浓缩,电子密度高,无核泡,纵切似辣椒状,核后端内凹形成核后窝。中段加长,结构复杂,线粒体演化成线粒体鞘,螺旋状包绕轴丝。精子末段由轴丝及包绕轴丝的质膜组成,轴丝为典型的“9＋2”结构。比较了平疣桑椹石磺精子与相关腹足类精子结构的异同,进一步证实了腹足纲贝类精子结构之间的区别主要在于顶体有无及形态,精核的长短与外形、中段线粒体的数目及其排列方式等。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

Characterization of the Lipids of Six Strains of Bacteroides ruminicola

The lipids of six strains of Bacteroides ruminicola were characterized. The nonpolar lipid accounted for 6 to 24% of the total lipid and was composed of diglycerides, triglycerides, and free fatty acids. The phospholipid fraction contained phosphatidylethanolamine, phosphosphingolipids, and trace quantities of phosphatidic acid. In three strains the phosphosphingolipid fraction made up more than half of the total lipid. The fatty acids in the nonpolar, acyl- and phosphosphingolipid consisted of a homologous series of branched and normal chains from 12 to 19 carbons. The long-chain base isolated from the phosphosphingolipids consisted of a homologous series of branched and normal chains from 14 to 24 carbons.     

植物学(被子植物分类部分) 教材中若干问题的商榷

本文对《植物学(被子植物分类部分)》教材(吴国芳等,1992)中如下问题与同行商榷：(1)关于克朗奎斯特(Cronquist)的被子植物分类系统;(2)关于金鱼藻科(Ceratophyllaceae)的分类位置;(3)关于被子植物分类原则;(4)关于插图与特征描述是否一致的问题;(5)关于分类群特征描述中的若干问题。     

Testing Equality of Coefficients of Variation of Two Populations

The test statistics are proposed for testing the equality of the coefficients of variation of two normal populations based on independent samples. The asymptotic distributions of the statistics are approximated by well-known distributions. The empirical sizes and powers of these statistics are computed and compared.     

Incorporation of neurons of transplants of embryonal rat neocortex in the achievement of sensory function of the cerebral cortex of the recipient

The barrelfield of the adult rats was removed by suction and embryonic tissue of the somatosensory neocortex was transplanted into the cavity. Spontaneous and evoked activity of the grafted neurones was investigated extracellularly 2-3 months after the grafting. The light microscopy of the grafts revealed the presence of normal neuronal cells, but their distribution was diffuse, and they were not organized into barrels as in intact neocortex. The background activity of grafted neurones depended upon the level of the recipient's anaesthesia. The response types of the grafted neurones to vibrissae deflection and to tactile stimulation of the host body surfaces, their latencies and lability did not differ from such of the intact somatosensory cortex, but the receptive fields of the grafted neurones were larger. There was also substantial convergence of inputs from other surfaces upon the grafted neurones. The effectiveness of stimulation of the various skin areas was determined by the proximity of their neocortical representations to the graft.     

Composition of cell walls of 2 mutant strains of Streptomyces chrysomallus

The cell walls and peptidoglycans of two mutant strains, Streptomyces chrysomallus var. carotenoides and Streptomyces chrysomallus var. macrotetrolidi, were studied. The strains are organisms producing carotenes and antibiotics of the macrotetrolide group. By the qualitative composition of the peptidoglycans the mutants belong to Streptomyces and are similar. Their glycan portion consists of equimolar quantities of N-acetyl glucosamine and muramic acid. The peptide subunit is presented by glutamic acid, L, L-diaminopimelic acid, glycine and alanine. The molar ratio of alanine is 1.2-1.3. The mutant strains differ in the content of carbohydrates, total phosphorus and phosphorus belonging to teichoic acids. Teichoic acids of the cell walls of the both strains are of the ribitolhosphate nature. The cell walls of the mutants contain polysaccharides differing from teichoic acids and consisting of glucose, galactose, arabinose and fucose. The influence of the cell wall composition of the mutant strains on their morphology and metabolism and comparison of the data relative to the mutant strains with those relative to the starting strain are discussed.     

中华花龟五种器官组织学观察

利用石蜡切片法对中华花龟的心脏、肝脏、脾脏、肺和肾脏等组织器官进行了组织学观察.结果显示心肌的特点是暗带较窄,心肌纤维束状排列.肝脏分3叶,肝实质内结缔组织少,肝小叶分界不清楚.脾脏分被膜和实质两部分,实质由白髓和红髓构成,白髓包括椭球周围淋巴鞘(PELS)和动脉周围淋巴鞘(PALS),红髓由脾索和脾窦组成,未发现淋巴小结和生发中心.肺一对,为长形扁平囊,肺泡囊状,肺泡内可见管壁的结节状膨大.肾脏由肾小体、颈段、近曲小管、中间段、远曲小管和收集管6部分构成,肾小体由肾小球和肾小囊组成,在肾小体附近可见致密斑样结构.     

Results of cytogenetic studies of the consequences of the Chernobyl accident

The selected results of the cytogenetic studies of the Chernobyl accident consequences were summarised. The chromosomal aberrations were used as a method of biodosimetry for a dose assessment for victims during the initial period after the Chernobyl accident. A good correlation between doses calculated based on chromosomal aberrations (dicentrics) and severity of acute radiation syndrome observed in clinic was found. The biodosimetry based on conventional cytogenetic technique (dicentrics) has been unsuccessful for various groups (rehabilitation workers, evacuees, inhabitants of contaminated areas) sampled long time after the Chernobyl accident. The possible reasons of the failure are analysed. The original results of multiaberration cell yield observed in different cohorts of the Chernobyl victims are presented. The problems related to the phenomena are discussed.     

异丁香酚的生物转化及香兰素的合成

利用粘质沙雷氏菌菌株AB 90027产生的离体酶催化异丁香酚进行生物转化,结合TLC、GC、UV-VISI、R等测试手段对异丁香酚的转化途径进行了探讨,借助薄层扫描法对不同反应体系下产物香兰素的产率作了比较,并研究了可催化异丁香酚合成香兰素的酶在细胞的存在位置。结果表明:在酶的作用下,异丁香酚分别经过阿魏酸和香兰素两条途径开环降解成小分子,中间产物香兰素产率可达10.90%,催化合成香兰素的酶主要是胞外酶。     

Compartmentalization of metabolism of spatially-delimiting amino acid pools of yeast cells

The spatially different amino acid pools (i.e. cytoplasmic, vacuolar and mitochondrial) of yeast cells are metabolically compartmentalized. The accumulation of amino acids in these pools occurs at different rates; the highest rates are observed for glutamate and alanine. The former is predominantly accumulated in the cytoplasm, the latter--in the vacuoles. The renewal rates of the amino acid pools are also different. Each of them contains at least two subpools, readily convertible and relatively stable ones. The readily convertible subpools of the cytoplasmic and mitochondrial pools predominantly contain glutamate, aspartate, valine and alanine; that of the vacuolar pool--alanine. The bulk of the readily convertible alanine subpool (67%) is localized in the vacuoles, that of glutamate and aspartate (85 and 68%, respectively)--in the cytoplasm.     

F肌动蛋白作为胞间连丝组分的结构与生理学证据

以蒜 (AlliumsativumL .)瓣鞘外表皮为材料 ,利用荧光特异探针与共焦镜检术 ,结合透射电镜与免疫金标记对表皮细胞间胞间联络的性质、结构进行了系统观察。结果表明 ,加厚壁上的通道是由狭长的管状胞质和初生纹孔场上成束的胞间连丝衔接组成 ,前者实为原生质体的一部分。单个胞间连丝的孔径为 6 0～ 70nm ,属正常胞间连丝范围 ,它们乃相邻细胞间共质联系的所在。荧光探针TRITC_Phalloidin (TRITC_Ph)标记的结果显示 ,整个通道上呈现红色荧光的纤索在接近初生纹孔场处明显变窄 ,与超微结构观察中所见的结构特点相吻合 ,共焦镜下观察到的初生壁上的荧光亮斑乃初生纹孔场中成束胞间连丝被标记的反映 ,从而有效地证实了F肌动蛋白在常态胞间连丝上的存在。免疫金标记实验显示在管状胞质中和胞间连丝上有金颗粒分布 ,这一结果为证实荧光标记物具肌动蛋白性质提供了有说服力的补充。     

Current status of the problem of quantitative estimation of cytogenetic effects of low doses of radiation

The results of the author's own experimental studies and the literature on the cytogenetic effects in human lymphocyte culture induced by low-level radiation are presented. The quantitative regularities of the occurrence of structural chromosome damages in the genome of human somatic cells under the effect of low doses differ from those induced by high doses of ionizing radiation. The adequacy of extrapolating the risk of harmful after-effects from high-to low-level radiation is discussed.     

Age-related features of the metabolism of fatty acid components of phospholipids of the cell nuclei of rat liver under the effect of dietetic factors

The metabolism of nuclear phospholipid acyl components of liver in uneven-aged rats was studied in vitro under different dietary fat implications. The activity of phospholipases A1 and A2 in the nuclei was found to sharply increase in animals pretreated with excess of fat. The incorporation of labelled palmitic, oleic, linoleic and arachidonic acid into nuclear phospholipids is under control of age and diet manipulations. The observed changes in the level of fatty acids metabolism are more pronounced in cell nuclei of the young rat liver. The lipid composition of cell nuclei in the test 3-month old animals does not differ from that of the control animals. At the same time dietary implications induce deep changes in the composition of nuclear lipids in 24-months old animals.     

瘤背石磺的精子结构

用光学显微镜和透射电子显微镜技术研究了瘤背石磺精子的结构特点,分析了其生理生态适应性以及在肺螺亚纲系统演化中的意义。瘤背石磺的精子由头部、中段和末段组成。头部由奶嘴形的顶体和长圆筒状的细胞核构成。顶体包括顶体囊和顶体构架体两部分;两者的内含物都分布均匀,电子密度稍低于细胞核;顶体基部平整,与核前端之间有一空隙,内含物电子密度极低。细胞核由电子密度高的均匀颗粒物质组成,并出现核泡;核的后端有一"杯形"的凹陷,称为核后窝。中段结构复杂,主要包括一对位于核后窝内的中心粒、轴丝、质膜、线粒体及由线粒体衍生的糖原质螺旋体、基质层和类晶体层等。末段由"9 2"结构的轴丝及外包的质膜组成,无糖原质螺旋体和其它线粒体衍生物。比较瘤背石磺精子与肺螺亚纲其它物种的精子结构,我们认为该物种的精子属于"进化型",是一类在进化地位中比基眼目高等的动物。