两种海马鳃组织和消化道的黏液细胞类型及分布

运用阿新兰(AB,pH 2.6)和过碘酸雪夫氏(PAS)反应染色方法,对三斑海马(Hippocampus trimaculatus)和日本海马(H.japonicus)鳃组织与消化道中的黏液细胞类型及分布进行了研究。染色结果显示:两种海马的鳃组织和消化道中均含有黏液细胞,日本海马的鳃组织中含有Ⅰ型和Ⅳ型黏液细胞,三斑海马的鳃组织中含有Ⅰ型、Ⅲ型和Ⅳ型黏液细胞。两种海马消化道各部位的黏液细胞类型和数量有明显差异:日本海马的食道中Ⅰ型细胞最多,而三斑海马的食道中Ⅳ型细胞最多;日本海马的前肠中只含有Ⅰ型细胞,而三斑海马的前肠中含有Ⅰ型、Ⅲ型和Ⅳ型细胞,其中Ⅰ型细胞含量最多;日本海马的中肠中含有Ⅰ型、Ⅲ型和Ⅳ型细胞,其中Ⅲ型细胞含量最多,而三斑海马中肠中只含有Ⅰ型细胞;日本海马与三斑海马的后肠中都分布有Ⅰ型、Ⅱ型、Ⅲ型和Ⅳ型细胞,两者不同的是,日本海马的后肠中Ⅲ型细胞含量最多,三斑海马的后肠中Ⅳ型细胞含量最多。     

中华蟾蜍与黑斑蛙消化道黏液细胞的观察

目的：探索两栖类动物消化道黏液细胞的类型与分布规律。方法：利用阿利新蓝与过碘酸雪夫试剂染色法对中华蟾蜍（Bufo bufo gargazizans）、黑斑蛙（Rana nigromaculata）消化道黏液细胞进行石蜡切片和染色。结果与结论：黏液细胞表现为4个类型：Ⅰ型玫瑰红色;Ⅱ型蓝绿色;Ⅲ型紫红色;Ⅳ型蓝紫色。两种动物食管黏膜上皮中黏液细胞主要是杯状细胞,其中中华蟾蜍的黏液细胞主要为Ⅱ型和Ⅳ型细胞,黑斑蛙的黏液细胞主要Ⅲ型细胞。胃体柱状黏膜上皮细胞与胃腺颈细胞主要为Ⅰ型和Ⅲ型细胞,黏原颗粒主要集中在细胞的核上区。胃腺浅部有成团分布并着色较浅的黏液细胞,其中黑斑蛙胃腺黏液细胞主要为Ⅰ型和Ⅲ型细胞,中华蟾蜍胃腺黏液细胞主要为Ⅲ型和Ⅳ型细胞。小肠杯状细胞主要为Ⅲ型和Ⅳ型细胞。大肠杯状细胞主要为Ⅱ型和Ⅳ型细胞。     

金丝桃属植物叶中分泌结构的比较解剖学研究

利用整体透明法、石蜡制片法和半薄切片法,对金丝桃属9组43种l亚种1变种的植物叶分泌 结构的类型、形态、结构和分布进行了比较研究。结果表明,分泌结构是金丝桃属植物叶片普遍的结构特征,根据其分泌结构的特征,可划分为分泌细胞团、分泌囊(道)和韧皮部中分泌小管道等3种分泌结构。其中,分泌细胞团按其在叶片的分布可分为叶缘型和散生型;分泌囊按其在叶横切面中的位置可分为栅栏组织型、海绵组织型、居中型(位于栅栏组织型与海绵组织型之间)和横跨叶肉组织型。根据分泌囊和分泌细胞团在该属植物叶中的分布可划分为3种类型：(1)只有分泌囊的类型;(2)只有分泌细胞团的类型;(3)具分泌囊和分泌细胞团的类型。两种主要分泌结构的类型、分布密度、分布位置及其形态等方面在组间和种间均存在—定的差异,对金丝桃属属以下等级的区分具有一定意义。在此基础上,对该属分泌结构的形态演化以及金丝桃属各组间的亲缘关系进行了探讨。     

巴西彩龟与中华鳖消化道粘液细胞组织化学染色

利用阿利新蓝和过碘酸雪夫试剂染色对巴西彩龟、中华鳖消化道粘液细胞的类型与分布进行了观察,结果显示消化道粘液细胞表现为4种类型：Ⅰ型玫瑰红色;Ⅱ型蓝绿色;Ⅲ型紫红色;Ⅳ型蓝紫色。食道前部粘膜上皮为复层上皮,粘液细胞形态多样,Ⅰ、Ⅱ、Ⅲ、Ⅳ类型均有,食道中部与后部粘膜上皮为柱状上皮,其内有密集排列的杯状细胞,主要是Ⅱ型、Ⅲ型和Ⅳ型细胞。胃体柱状粘膜上皮细胞与胃腺颈部细胞主要为Ⅰ型和Ⅲ型,粘原颗粒主要集中在细胞的浅部。胃腺粘液细胞主要为Ⅰ型和Ⅲ型,着色较浅。小肠杯状细胞主要为Ⅲ型和Ⅳ型。大肠、泄殖腔杯状细胞主要为Ⅱ型和Ⅳ型。     

日本鬼You背鳍棘毒腺中Ⅰ,Ⅱ型毒腺细胞关系的探讨

日本鬼Ｙｏｕ背鳍棘毒腺中有两种类型毒腺细胞－－Ⅰ型细胞和Ⅱ型细胞。两咱细胞结构明显不同。本文用形态学方法探讨Ⅰ型与Ⅱ型的细胞的关系。结果表明：毒腺组织中Ⅰ型细胞光镜下有的胸质内可见浅洒点样结构,并且在不同的细胞内其浅染点状结构的多少有差异;电镜下Ⅰ型细胞腊结构差异较大,有的Ⅰ型细胞的脂质双层膜性结构清楚;有的细胞膜外侧可见膜包小泡;有的细胞内侧面也见小泡形成、融合,使脂质双层膜间隙变宽,其内可见膜     

金星蕨科16种植物叶表皮特征的研究

利用光学显微镜对金星蕨科(Thelypteridaceae)8属16种植物的叶表皮形态进行了观察和研究,为金星蕨科植物的系统演化及分类提供科学依据。结果表明:(1)16种金星蕨科植物的叶片表皮细胞为不规则型,表皮细胞垂周壁大多呈深波状。(2)气孔为下生型,多呈椭圆形;共观察到6种气孔器类型(极细胞型、腋下细胞型、聚合极细胞型、聚腋下细胞型、不规则型和聚围绕细胞型),每种植物具2~5种不同类型的气孔器。(3)金星蕨科8属植物在表皮细胞大小、垂周壁形状、气孔大小和形状、气孔密度、气孔指数和气孔器类型上存在一定的属间差异。     

蜡样芽孢杆菌主要毒素及检测方法的研究进展

蜡样芽孢杆菌(Bacillus cereus)是一种普遍存在的食源性病原菌,可造成腹泻和呕吐两种类型的食物中毒和其他类型的疾病根据蜡样芽孢杆菌引起食物中毒的症状,其毒素可分为致腹泻型肠毒素和致呕吐型肠毒素,其中溶血性肠毒素BL、非溶血性肠毒素和细胞毒素K是引起腹泻型食物中毒的3种主要毒素,cereulide为致呕吐型肠...     

海带对双歧杆菌促生长作用的研究

探讨海带对双歧杆菌生长的促进作用。选用海带以平板打洞法、试管法对青春双歧杆菌和婴儿双歧杆菌进行了体外生长促进实验。结果发现,两种双歧杆菌在含有海带汁洞口周围,菌苔生长均较为茂盛;随着离洞口的距离渐近,菌苔逐渐增厚;随着海带汁浓度的增加,菌苔茂盛程度增加,活菌数亦增多;在海带培养基中,双歧杆菌增殖１２ 小时基本达到稳定期,与对照管比较,增殖速度快而稳定。结果表明海带对双歧杆菌增殖有稳定的促进作用。     

四指马鲅稚鱼、幼鱼和成鱼消化道黏液细胞组织化学研究

采用常规石蜡组织切片及阿利新兰–高碘酸雪夫–试剂(AB-PAS,AB,p H2.5)染色方法对四指马(Eleutheronema tetradactylum)稚鱼、幼鱼和成鱼消化道中黏液细胞的组织化学特征进行观察。35日龄稚鱼消化道黏液细胞数量少,种类单一,食道含数量较多的II型黏液细胞,偶见I型黏液细胞;幽门盲囊未检测出黏液细胞的分布;前肠以I型黏液细胞为主,有少量III型黏液细胞、中肠和后肠均只有II型黏液细胞。65日龄幼鱼消化道各段黏液细胞数量明显增多,种类丰富,食道、前肠和中肠均含I、II、III、IV型4种类型的黏液细胞,其余均含至少两种类型的黏液细胞,食道黏液细胞密度最大,其次是后肠。成鱼食道、幽门盲囊均含II型和IV型黏液细胞,但后者两型黏液细胞数量都比较少;胃部含有大量I型黏液细胞,胃腺区域则以IV型黏液细胞为主;肠道只含III、IV型黏液细胞,黏液细胞密度从前到后呈递增规律。稚鱼、幼鱼、成鱼消化道黏液细胞的分布特点体现消化道结构功能逐渐发育完善的规律。     

瓦形细胞在广义锦葵科中的分布及其系统学意义

基于文献和作者的研究,该文讨论了瓦形细胞的识别、类型、变异及在广义锦葵科中的分布及其系统学意义。瓦形细胞是一种特殊射线细胞,呈不定的横列,常分散在横卧细胞之间,常无细胞内含物,其宽度远比横卧细胞为小,根据瓦形细胞与横卧细胞高度、宽度的相对大小,分为榴莲型、中间型和翅子树型3种类型,目前为止仅在广义锦葵科9个亚科中的7亚科39个现存属和5个化石属中发现;榴莲型、翅子树型和中间型瓦形细胞分别在22、20和5个属中发现,具有中间型的属同时具有榴莲型或/和翅子树型。仅翅子树型和中间型瓦形细胞在化石中发现,榴莲型可能比翅子树型古老。瓦形细胞在广义锦葵科中的分布,对研究一些类群的系统发育有意义。     

Syndecans play dual roles as cell adhesion receptors and docking receptors

Syndecan are a family of cell surface heparan sulfate proteoglycans that act as cell surface receptors. Most cell surface receptors have a limited number and type of ligand interactions, responding only to the binding of (a) specific ligand(s). In contrast, syndecans can interact with various numbers and types of ligands, and thus play more diverse roles than others. Various syndecan functions have not yet been fully classified and categorized, but we herein review previous studies suggesting that syndecans play dual function as cell surface receptors by acting as both adhesion receptors and docking receptors. Through this dual regulatory function, syndecans are capable of regulating both intra- and extracellular activities, potentially altering a variety of cell behaviors.     

Mitochondrial DNA molecules and virtual number of mitochondria per cell in mammalian cells

A new biochemical method for estimating the virtual number of mitochondria (mt) per cell was developed and used together with a plasmid probe to measure mt DNA/mitochondrion and mt DNA/cell. These methods were used in five cell types from four mammalian species. Mt DNA/mitochondrion was essentially constant in all cell types (mean 2.6 +/- 0.30 SE mitochondrial DNA molecules/mt). Mt DNA molecules/cell encompassed an eight-fold range between various cell types (low 220 +/- 6.2; high 1,720 +/- 162 mt DNA molecules/cell). Virtual mt number/cell ranged from 83 +/- 17 to 677 +/- 80 (SE) mt/cell in various cell types. All five mammalian virtual mitochondria contained the same genomic mass. The number of virtual mitochondria per cell and amount of mt DNA per cell appear to be closely regulated within a given cell type but differ widely from cell type to cell type.     

Tapping culture--an improved method for cell suspension culture.

A new culture vessel was designed for cell suspension culture. A silicone-covered magnet bar fixed by one end to the side wall of the bottle was held horizontally a short distance from the bottom. A standard type magnetic stirrer was used. In contrast to the conventional horizontal movement of "stirring" in cultures the bar moves vertically with a "tapping" motion. This improvement resulted in less cell injury, higher rate of cell proliferation and formation of fewer bubbles than in the conventional type. Nine cell types were simultaneously cultivated in tapping, stirring and stationary culture. All cell types proliferated more luxuriously in tapping cultures then in stirring cultures. Serial cultivation of cells in tapping cultures was also successful.     

Novel knowledge-based potentials for ligand docking: variational approach to the old problem

The variational approach of evaluation for knowledge-based potentials is considered for the first time. In this approach, the problem to derive knowledge-based potentials is solved as the optimization task in the multiparametric model of atom types, reference states and interaction cutoff radii. Using analogy to liquid state theory we offered four new reference states and derived corresponding knowledge-based potentials. The cutoff radii and atom types are optimized to minimize averaged root-mean square deviations (RMSD) of the ligand docked positions regarding to the experimentally determined poses. The number of atom types is varied on the developed atom type tree with 6 root (C, N, O, S, P and the halogen type) and 49 apical atom types. We showed a pronounced effect of atom type choice on docking accuracy and proved that splitting of elements C, N and O of the periodic system up to the 18 optimal atom types essentially improves docking accuracy.     

Colony stimulating factor-1 receptor as a target for small molecule inhibitors

Imatinib, dasatinib, sunitinib, CEP-701, and PKC-412, ATP-competitive small molecule inhibitors of type III receptor tyrosine kinases c-KIT and/or FLT3, were evaluated for binding to the closely related receptor, FMS, by docking into models of inactive and active conformations of the FMS kinase domain. To confirm the docking predictions, the drugs were tested for their activity and selectivity in inhibiting cell proliferation and FMS phosphorylation upon stimulation by the FMS ligand, CSF-1. All five drugs inhibited FMS activity. Imatinib, dasatinib and CEP-701 represent three different types of interactions determining drug potency and selectivity.     

Aphid-symbiotic bacteria cultured in insect cell lines

The cells and tissues of many aphids contain bacteria known as "secondary symbionts," which under specific environmental circumstances may be beneficial to the host insect. Such symbiotic bacteria are traditionally described as intractable to cultivation in vitro. Here we show that two types of aphid secondary symbionts, known informally as T type and U type, can be cultured and maintained in three insect cell lines. The identities of the cultured bacteria were confirmed by PCR with sequencing of 16S rRNA gene fragments and fluorescence in situ hybridization. In cell lines infected with bacteria derived from aphids harboring both T type and U type, the U type persisted, while the T type was lost. We suggest that the two bacteria persist in aphids because competition between them is limited by differences in tropism for insect tissues or cell types. The culture of these bacteria in insect cell lines provides a new and unique research opportunity, offering a source of unibacterial material for genomic studies and a model system to investigate the interactions between animal cells and bacteria. We propose the provisional taxon names "Candidatus Consessoris aphidicola" for T type and "Candidatus Adiaceo aphidicola" for U type.     

Skeletal muscle satellite cell diversity: satellite cells form fibers of different types in cell culture

Following skeletal muscle injury, new fibers form from resident satellite cells which reestablish the fiber composition of the original muscle. We have used a cell culture system to analyze satellite cells isolated from adult chicken and quail pectoralis major (PM; a fast muscle) and anterior latissimus dorsi (ALD; a slow muscle) to determine if satellite cells isolated from fast or slow muscles produce one or several types of fibers when they form new fibers in vitro in the absence of innervation or a specific extracellular milieu. The types of fibers formed in satellite cell cultures were determined using immunoblotting and immunocytochemistry with monoclonal antibodies specific for avian fast and slow myosin heavy chain (MHC) isoforms. We found that satellite cells were of different types and that fast and slow muscles differed in the percentage of each type they contained. Primary satellite cells isolated from the PM formed only fast fibers, while up to 25% of those isolated from ALD formed fibers that were both fast and slow (fast/slow fibers), the remainder being fast only. Fast/slow fibers formed from chicken satellite cells expressed slow MHC1, while slow MHC2 predominated in fast/slow fibers formed from quail satellite cells. Prolonged primary culture did not alter the relative proportions of fast to fast/slow fibers in high density cultures of either chicken or quail satellite cells. No change in commitment was observed in fibers formed from chicken satellite cell progeny repeatedly subcultured at high density, while fibers formed from subcultured quail satellite cell progeny demonstrated increasing commitment to fast/slow fiber type formation. Quail satellite cells cloned from high density cultures formed colonies that demonstrated a similar change in commitment from fast to fast/slow, as did serially subcloned individual satellite cell progeny, indicating that the observed change from fast to fast/slow differentiation resulted from intrinsic changes within a satellite cell. Thus satellite cells freshly isolated from adult chicken and quail are committed to form fibers of at least two types, satellite cells of these two types are found in different proportions in fast and slow muscles, and repeated cell proliferation of quail satellite cell progeny may alter satellite cell progeny to increasingly form fibers of a single type.     

The key role of atom types, reference states, and interaction cutoff radii in the knowledge-based method: new variational approach

We present a variational method to derive knowledge-based potentials. The method is based on an optimization procedure of objective variables: atom types, reference states, and interaction cutoff radii. We suggest and apply new unsymmetrical reference states. The cutoff radii and atom types are optimized to improve docking accuracy of the corresponding potentials. The atom types are varied along an atom type tree, with 6 root and 49 top atom types, and the set of 18 optimal atom types is obtained. We demonstrate strong dependence between the choice of atom types and the docking accuracy of the potentials derived with these atom types. The averaged root-mean square deviations (RMSDs) of the ligand docked positions relative to the experimentally determined positions decrease when the elements C, N, O are split into the optimal types.