白腹锦鸡,红腹锦鸡,中国雉鸡SC组型的比较研究

以微铺展—硝酸银染色技术制备三种鸡的SC标本,进行电镜观察。结果表明:三种鸡的SC组非常相似,即2n=82,ZZ/ZW型性别决定,雄性为ZZ。除1号SC和Z-SC为中着丝粒外,其余均为端着丝粒。Z-SC的相对长度有明显的细胞间差异;平均相对长度度介于第3和第4号SC之间。三者SC组型上的差异主要表现在相应SC长度上的不同。并对其亲缘关系及在鸟类进化中的可能地位进行了讨论。此外,在微铺展法制备的锦鸡精母细胞SC标本中还发现了巨大中心粒,这在高等动物尚属首次。     

中国雉鸡减数分裂SC组型和有丝分裂染色体组型的比较研究

以微铺展-硝酸银染色技术制备中国雉鸡SC标本。电镜的定量SC组型分析表明:中国雉鸡的SG组型和有丝分裂染色体组型有良好的一致性。并对个别SC与其相应的有丝分裂染色体在长度、形态上的差异以及SC组型分析在鸟类细胞遗传学研究中的可能意义进行了讨论。     

豚鼠精母细胞联会复合体的电镜观察

以微铺展法制备豚鼠精母细胞联会复合体标本,经硝酸银染色后作电镜观察,建立了SC组型．与有丝分裂染色体组型比较,发现二者有良好的一致性．在粗线期,X,Y轴的配对区很短,配对区的X轴和Y轴没有明显变细．未发现银染SC具有着丝粒,并对可能的原因作了分析讨论．     

中华鳖精母细胞联会复合体的研究

本文以微铺展技术制备中华鳖精母细胞联会复合体标本,经硝酸银染色后电镜观察,分析了SC组型.并与有丝分裂染色体组型相比较,发现二者有着良好的一致性,而且微小染色体的SC结构和着丝粒清晰,未发现形态上有分化的性染色体.中华鳖SC的研究为其细胞遗传学及性别决定机制提供了重要的依据.     

中国雄鸡减数分裂SC组型和有丝分裂染色体组型的比较研究

以微铺展一硝酸银染色技术制备中国准鸡sc标本。电镜的定量SC组型分析表明：中国难鸡的so 组型和有丝分裂染色体组型有良好的一致性。并对个别SC与其相应的有丝分裂染色休在长度、形态士 的差异以及sc组型分析在鸟类细胞遗传学研究中的可能意义进行了讨论。     

生物材料表面蛋白质微图形对人体软骨细胞形态及蛋白表达的影响

主要研究采用微接触印刷术在生物材料表面制备的细胞外基质蛋白微图形对人体软骨细胞粘附、铺展以及蛋白质表达等细胞行为的影响．研究结果表明,蛋白质微图形表面对细胞的粘附、铺展、排列以及细胞蛋白质表达具有明显的影响．细胞优先粘附在微图形蛋白区域,微图形形状以及尺度明显影响细胞的粘附形态以及铺展程度,同时也影响细胞生长过程中的Ⅱ型与Ⅵ型胶原蛋白的表达,细胞的铺展行为与细胞的蛋白质表达具有一定的正相关性,铺展较好的细胞表现出更好的Ⅱ型与Ⅵ型胶原蛋白表达．结果表明,通过在材料表面制备细胞外基质蛋白微图形可以有效调控人体软骨细胞的生长行为与功能．     

普通小麦联会复合体发育过程的电镜观察

以改进的去污剂微铺展技术制备普通小麦减数分裂联会复合体标本,并对联会复合体发育的全过程作了详细的电镜观察和描述。结果表明,小麦SC以多点式起始方式于偶线期开始形成;随SC的发育,新的SC形成和已有SC片断的延伸并存;此外,在同一核内不同二价体之间,染色体配对和SC形成并不同步;SC成熟于粗线期,而以破碎方式解体,消失于双线期。在偶线期还观察到由同祖配对形成的多价体,但在随后阶段中这些多价体消失。对Ph基因的可能作用机制作了分析和讨论。     

褐斑大蠊精母细胞联会复合体研究

采用表面铺展法结合银染技术制备联会复合体标本,在光镜、电镜下进行观察。发现褐斑大蠊精母细胞联会复合体(SC)的结构及演变符合一般规律;SC的相对长度与有丝分裂染色体的相对长度之间存在着良好的吻合性;电镜下可观察到SC侧线本身的双股结构;分类描述了核内的几种颗粒,并对相关的一些问题进行了讨论。     

褐斑大蠊精母细胞联会复合体研究

采用表面铺展法结合银染技术制备联会复合体标本,再光镜、电镜下进行观察。发现褐斑大蠊精母细胞连会复合体(SC)的结构及演变符合一般规律;SC的相对长度与有丝分裂染色体的相对长度之间存在着良好的吻合性;电镜下可观察到SC侧线本身的双股结构;分类描述了核内的几种颗粒并对相关的一些问题进行了讨论。     

减数分裂联会复合体的制备技术

在生物减数分裂制片中 ,镜下只能看到同源染色体 ,而联会同源染色体的 SC却无法看到 ,本室改进后的微铺展——硝酸银染色技术制备的 SC片 ,在光镜下可以清晰地观察到 SC这一特殊结构。现以小白鼠精母细胞 SC样品制备为例 ,方法如下 :取性成熟的昆明种雄性小鼠 ,颈椎断离处死 ,取两侧睾丸 ,用 2 .2 %柠檬酸钠洗去脂肪等污物 ,去除白膜 ,在 0 .9%的生理盐水中剪碎 ,制成细胞悬液 ,在一牙科蜡 (或涂有石蜡的平面 )上滴加一直径约 1cm的 0 .4 %KCl液珠。取少量细胞悬液滴加在液珠面上 ,在表面张力的作用下 SC则铺展开 ,用涂有 0 .3% Formv…     

In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation

The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous system. SC-selective genetic manipulation in living animals is a powerful technique for studying the molecular and cellular mechanisms of SC myelination and demyelination in vivo. While knockout/knockin and transgenic mice are powerful tools for studying SC biology, these methods are costly and time consuming. Viral vector-mediated transgene introduction into the sciatic nerve is a simpler and less laborious method. However, viral methods have limitations, such as toxicity, transgene size constraints, and infectivity restricted to certain developmental stages. Here, we describe a new method that allows selective transfection of myelinating SCs in the rodent sciatic nerve using electroporation. By applying electric pulses to the sciatic nerve at the site of plasmid DNA injection, genes of interest can be easily silenced or overexpressed in SCs in both neonatal and more mature animals. Furthermore, this in vivo electroporation method allows for highly efficient simultaneous expression of multiple transgenes. Our novel technique should enable researchers to efficiently manipulate SC gene expression, and facilitate studies on SC development and function.     

Silver staining of synaptonemal complexes in surface spreads for light and electron microscopy

Synaptonemal complexes (SCs), axes of the X and Y chromosomes, and nucleoli in surface-spread preparations of spermatocytes are selectively stained for both light and electron microscopy by ammoniacal silver. Combined with a simple technique for transferring material from glass slides to grids, sequential light and electron microscopic analysis of full SC complements is possible with no further preparation. This new method has potential for both basic and clinical cytogenetic research.     

Application of Y chromosomal repetitive sequences to sexing mouse embryos

Identification of sex is often necessary to evaluate genetic or teratogenetic effects on embryonic development. A simple molecular technique to identify the sex of mouse embryos was studied using a Y chromosomal repetitive sequence (designated 145SC5). Since this technique does not require purification of DNA, it is particularly suitable for processing many embryos. Furthermore, 145SC5 detects 1% contamination of male DNA in a male-female DNA mixture. These results suggest that 145SC5 is a powerful molecular tool in a variety of studies on mouse development.     

Effect on scrotal circumference of trucking beef bulls medium and long distances

Scrotal circumference (SC) was measured both before and after 2- to 3-yr-old beef bulls were trucked either medium (138 km) or long (565 km) distances. Two SC measurement techniques were used, one recommended by the Society for Theriogenology and the “slip-off” technique. No differences (P > 0.05) were observed between pre-and post- trucking SC measurements using the Theriogenology technique when bulls were trucked either medium (n = 12; 35.9 ± 0.8 vs 35.8 ± 0.7 cm) or long (n = 16; 36.5 ± 0.5 vs 36.6 ± 0.4 cm) distances. However, when the SC of the same bulls was measured using the “slip-off” technique, there was a small, but significant (P < 0.05), reduction in SC for bulls trucked medium (38.0 ± 0.7 vs 37.5 ± 0.7 cm) and long (38.9 ± 0.4 vs 38.6 ± 0.4 cm) distances. Bulls having SC at or below the recommended minimum standard reacted no differently to the stress of trucking than did bulls having a SC well above the standard. Errors in measurement technique, severe weather conditions and testicular degeneration over an extended interval are discussed in terms of their potential contribution to the reduction in SC observed by some cattlemen. These data support the use of the SC measurement technique recommended by the Society for Theriogenology because its accuracy is not affected by trucking of bulls. The suggested implementation of an adjustment period between the trucking of beef bulls and measurement of their SC using the Theriogenology technique is not supported.     

Where intestinal epithelial stem cells are localized? About molecular markers

Using stem cells as an example the review considers a new history and methodology of search for stem cells (SC), found in tissues of adult Homo sapiens and Drosophila melanogaster organisms. These studies of SC resulted in several original hypotheses explaining their unusual features. Impressive progress recently achieved in this direction (2008–2010) is associated with employment of new methods of somatic recombination for long-term registration of various strains of differentiated cells, early and distant SC progeny. 1) Although anatomic localization of intestinal epithelium cells lacking marked morphological and biochemical differentiation markers (the lower third of intestinal and colon crypts) is known for about 40 years results of their experimental identification, isolation and detection of their functional characteristics still represent the subject for discussions. Particularly, it remains unclear, which SC are involved in crypt regeneration: the same as those involved into homeostatic renewal or their various subpopulations or early SC progenies acquired stem features by reprogramming? 2) In addition, most detected biochemical markers of potential SC are common for SC from other tissues of embryonic and mature organisms so it is possible to apply method developed for intestinal epithelium for their isolation. 3) Data on induction of intestinal epithelium polyps and neoplasias by mutations in genes encoding SC markers and identification of biochemical characteristics of potential SC in these tumors support the hypothesis of stem tumor cell origination from normal SC or their earliest progeny. In general, facts considered in this review may be useful for both development of optimal methods for the use of SC in cell therapy (as the source of humoral factors), regenerative medicine (as the source of differentiated cells for restoration of injured tissue), and also for targeted search of antitumor drugs (SC as the target) and preparations modifying genetic and epigenetic reactions of SC to genotoxic and stress treatments.     

Use of the tape stripping technique for directly quantifying esterase activities in human stratum corneum

The enzymes secreted in the intercellular spaces of stratum corneum (SC), the outermost layer of the epidermis, are thought to be involved in normal desquamation and skin barrier function. Their activity can barely be measured due to the difficulty in isolating enough biological material. Human SC layers were obtained from the forearm of healthy volunteers by the tape stripping technique. Assays for esterase activities were carried out in specially designed plates which contained the SC blotted on tape strips, using various fluorescent methylumbelliferone acyl esters as substrates. Triacylglycerol hydrolase activities were also studied by this method. By using radiolabeled triolein and fluorescent 4-methylumbelliferyl 7-oleate as substrates, true lipase activities could be detected and quantitated in SC at pH 5.5 and 7.5. These activities were shown to be strongly inhibited by tetrahydrolipstatin while this was not the case with 4-methylumbelliferyl 7-heptanoate. The method described here combines the painless tape stripping technique with a sensitive plate assay analysis. Since the whole process needs little manipulation, this method can permit rapid quantitation of multiple enzyme activities from a single strip. Therefore, it will permit the study of the involvement of enzyme activities in epidermis aging and skin pathologies.     

Purification of Schwann cells from adult rats by differential detachment

Differential detachment by collagenase treatment is a new and efficient method for Schwann cell (SC) purification. As its effect on adult animals remains unclear, we have investigated the possibility of SC purification from adult rats. To avoid any systematic bias, Schwann cell purity before and after purification were compared by morphology, immunostaining of P75^NTR and S100 and flow cytometric analysis. The final SC purities reached 99% as confirmed by three independent analyses SC purity and the cell yields were above 10⁶ cells after two rounds of purification. The method of differential detachment is also suitable for SC purification in adult rats and could be useful for research and clinical applications.     

Two new methods for preparing a unique stratum corneum substitute

Stratum corneum lipids play an important role in the barrier function of the skin. An in vitro permeation model consisting of synthetic lipids has previously been developed to replace human stratum corneum (SC) in permeation studies. This model is referred to as the stratum corneum substitute (SCS). In order to improve its reproducibility and to increase the efficiency in preparing the SCS, two new preparation methods are developed. Subsequently the properties of the SCS prepared by the various methods, i.e. the manual airbrush method, the rotor airbrush method and the linomat method, are investigated. The results show that the SCS prepared with the various methods share the properties of a uniform lipid composition and lipid distribution. Furthermore, irrespective of the preparation method, the lipids form crystalline lamellar phases, mimicking the lipid organization and orientation in human SC. As a result, permeation profiles of benzoic acid through SCS are very similar to human SC. The rotor method increases the efficiency and reproducibility of the manual airbrush method, while the linomat method reduces the lipid loss during preparation and results in SCS with a more uniform membrane thickness. In conclusion, the linomat method was chosen as the preferred method for preparing the substitute.     

小鼠精母细胞联会复合体RNA组分的电镜研究

本文运用常规染色和Bernhard染色方法对切片标本中小鼠粗线期精母细胞联会复合体(SC)的超微结构和电镜细胞化学特点进行了研究。经常规染色后,可见SC由侧生组分(LE)、中央组分(CE)和L-C纤维组成;SC宽约210nm,LE宽约60nm,中央间隔区宽约90nm。在Bernhard染色标本中,SC的LE、CE和L-C纤维着色较深,说明其中含有RNA;SC各结构组分的宽度和形态特点与常规染色标本中的基本一致。本文讨论了SC中存在有RNA等问题。     

Low-flux electron diffraction study on body site dependence of stratum corneum structures in human skin

For analysis of the structure of human skin stratum corneum (SC), we introduced low-flux electron diffraction (ED) and developed a new statistical analysis method for obtained ED intensity profiles. By use of this method we compared the differences in the intercellular lipid organization on the SC corneocytes collected at human forehead, cheek, and forearm by the grid-stripping method. As a result, we found a significant regional difference in the distribution of lipid hydrocarbon chain packing domains in the SC; the ring-type ED pattern with orthorhombic symmetry was more often observed in the forearm SC than in the forehead and cheek SCs. We also found that the dependence of the background electron diffraction intensity on the modulus of the scattering vector differed significantly among them. The present method for the analysis of a large number of ED patterns of noninvasively obtained SC samples could be a powerful tool to scrutinize the structural difference between the SCs under various experimental conditions.