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。     

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.     

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。     

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).     

SARS病毒的种型变异之比较及其PCR的分子诊断技术应用

概述了SARS-CoV冠状病毒的基因组结构与功能,比较了它与其它冠状病毒的种型变异,并以生物信息学的方法 探讨PCR技术在进行SARS病毒早期诊断上的应用。     

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。     

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.     

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.     

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.     

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.     

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.     

Analysis of Headspace of Root of Levisticum officinale

The headspace of root of Levistlcum officinale was subjected to adsorb by means of XAD 4. The chemical components of the headspace obtained were analysed by GC/MS and GC/FTIR. 64 compounds have been seperated, of which 20 compounds were identified. The main compounds were monc, terpenoids and sesquiterpenoids, such as β-phellandrens (16.47%), citronellal (12.85%) and ligustilide (20.94%) etc.     

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。     

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.     

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.     

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.     

Spectrum of risk of malignancy in subcategories of 'atypia of undetermined significance'

Objective: To determine if focal 'nuclear atypia' or 'microfollicular architecture' portends a higher risk of malignancy than other subcategories of atypia of undetermined significance (AUS) in thyroid fine-needle aspirations (FNAs). Study Design: The frequencies of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) categories were calculated from 3,956 thyroid FNAs interpreted over a 26-month period at The Johns Hopkins Hospital after adoption of TBSRTC. TBSRTC criteria were applied strictly. The risk of malignancy, specifically for AUS subcategories, was analyzed by cyto-histo correlation. Results: Of the 133 cases diagnosed as AUS, 32% were found to have stageable carcinoma (not incidental microcarcinoma) on resection. When the subset of AUS with 'nuclear atypia' (AUS-N) was separated from other AUS cases, 48% (30/62) of them had stageable carcinoma on resection; of the AUS subset with 'microfollicular architecture' (AUS-F), 27% (8/30) were malignant on resection. The 'suspicious for papillary thyroid carcinoma' (SPTC) group maintained a higher risk of malignancy versus AUS-N (relative risk, RR 1.57; 95% CI 1.23-1.81). Conclusion: The subcategory of 'nuclear atypia' within AUS indicates a higher risk of malignancy than other subcategories of AUS but has a lower risk of malignancy than SPTC does. Thus, it is an important distinction with potential clinical implications.     

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.     

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.