Intercellular bridges of chick blastoderm studied by scanning and transmission electron microscopy

Summary Chick blastoderms were studied by scanning and transmission electron microscopy to identify by both methods a type of thread-like structure lying on the epiblast. The structure was identified by transmission microscopy as a long telophase bridge containing mid-body and spindle remnant. It apperas to provide cytoplasmic continuity between only 2 cells.Supported by a grant from The Medical Research Council of Canada.     

The ultrastructure of the spiral notosetae ofNicomache maculata Arwidsson (Polychaeta,Maldanidae)

Summary Scanning- and transmission electron microscopy show that the long, thin notosetae ofNicomache maculata are helical over much of their length, and that their finely feathered appearance is produced by a series of minutely spiny scales. The internal structure varies considerably from one end of the seta to the other. While a helical shape could result from a rotating or asymmetrical secretion-rate gradient across the chaetoblast, we raise the possibility that the spiral represents a warp in the seta following deposition of the setal material.     

Impact of thickness of GaN buffer layer on properties of AlN/GaN distributed Bragg reflectors grown by metalorganic chemical vapor deposition

We studied the impact of the thickness of GaN buffer layer on the properties of distributed Bragg reflector (DBR) grown by metalorganic chemical vapor deposition (MOCVD). The samples were characterized by using metallographic microscope, transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray diffractometer (XRD) and spectrophoto- meter. The results show that the thickness of the GaN buffer layer can significantly affect the properties of the DBR structure and there is an optimal thickn...     

Scanning transmission electron microscopy of dendritic spines stained by the Golgi method]

Scanning transmission electron microscopy of the dendritic spines of multipolar neurons in the cat inferior Colliculus was achieved on Golgi semi-thin sections. The three basic types of dendritic spines (ST, MS, TH) were identified. Scanning transmission electron microscopy provides a reliable method for a three dimensional view of these structures at high resolution and consequently a more accurate appreciation of their size. In addition, it could prove very useful in the quantitative analysis of the dendritic spines.     

The early differentiation of the perinotochordal connective tissue. A scanning and transmission electron microscopic study on chick embryos (author's transl)]

The early differentiation of the connective tissue was investigated in the perinotochordal zone of 2-3 day-old chick embryos. After characterizing the different tissue components by transmission electron microscopy, their arrangement and distribution were examined by SEM. The results are discussed with regard to the role of the extracellular material in embryonic tissue interactions.     

Muscular and nervous systems of the cubopolyp (Cnidaria)

Summary New observations on the morphology, anatomy, asexual reproduction and metamorphosis of the formerly unknown polyp of the tropical Cubomedusae resulted in the conclusion that a new class Cubozoa must be established and positioned between the Scyphozoa and Hydrozoa. This conclusion could be confirmed by the histological investigation of the cubopolyp's muscular and nervous systems by light and transmission electron microscopy.     

Giant collagen fibres in the gonopodium of the mosquitofishHeteradria formosa,Agassiz, 1853 (Pisces,Poeciliidae)

Summary The gonopodium of the mosquitofishHeteradria formosa was studied by transmission electron microscopy. In cross-section the gonopodium shows the following structure from the outside inwards: mutilayered epidermis, basal lamina and central supporting tissue, in which vessels and nerves are embedded. At the top of the gonopodium giant collagen fibres are found, which measure up to 150 m in length and 6 m in diameter. These fibres reinforce the gonopodium.This research was supported by the Deutsche Forschungsgemeinschaft. Address for reprints: Forschungsgruppe Dermatologie der Universität Heidelberg, Im Neuenheimer Feld 324, D-6900 Heidelberg.     

Formation of coronary arteries sprouting from the primitive aortic sinus wall of the chick embryo

Summary The formation of coronary arteries in chick embryos was observed by scanning electron microscopy on injected casts as well as by transmission election microscopy. Usually, 2–4 primitive coronary arteries appear from the right aortic sinus below the level of the cusp margin, and 1–3 from the left one. As development proceeds, the arteries are generally reduced in number to form a single definitive coronary artery on each side. Canalization of the arteries seems to take place by partially degenerative changes of the primordia.Thanks are given to Prof. M. Mato, Department of Anatomy, Jichi Medical School, Tochigi for valuable suggestions, and Dr R.J. Adams for stylistic suggestions. The skillful technical assistance of MrS. Ide is acknowledged.     

Visualisation of lectin binding sites on the surface of human platelets using lectins adsorbed to gold granules

Summary Washed human platelets have been incubated with the lectins WGA, ConA and RCA₁, adsorbed to differentsized gold particles. Plasma membrane receptors for each lectin were then located by scanning and transmission electron microscopy.Acknowledgments. We would like to thank Mlle Dominique Dupuis for technical assistance. This work was supported in part by grant No. CRL 78.5.128.1 from INSERM.     

聚丙烯腈原丝在预氧化过程中的HRTEM组织演变

采用高分辨透射电子显微镜(HRTEM)研究了聚丙烯腈原丝和预氧丝横截面超薄切片的微观组织,揭示了预氧化过程中原丝组织结构的演变机理。结果表明,晶区的非晶化转变是原丝在预氧化过程中组织结构演变的主要形式;而晶面间距的逐渐变宽则是导致非晶化转变的直接原因。     

Microorganisms seen by scanning and transmission electron microscopy in Legionnaires' disease from human lung.

In addition to several anomalous structures, other general forms of definitely rod-shaped microorganisms have been found by scanning and transmission electron microscopy in the lung tissue taken at autopsy from a patient who succumbed to confirmed Legionnaires' disease with extensive necrotizing lobar pneumonia. The microorganisms were greatly varied in size and shape. They were micrographed in the act of fission. These forms have been found to some extent throughout the tissue. No nickel was demonstrated, either in the lung tissue or in the microorganisms.     

Ciliated fibroblasts and smooth muscle cells in the rat uterus

Ciliation in endometrial fibroblasts and myometrial muscle cells of the rat was examined by transmission electron microscopy. Quantification of the number of ciliated cells during the estrus cycle did not show any firm relationship between ciliation and ovarian hormonal activity. In the case of most cilia, there is a spatial relationship between their basal centrioles and the Golgi complex, so that a Golgi-cilium complex is created. A possible role of ciliation in uterine fibroblasts and smooth muscle cells is discussed.     

Location of lectin receptors on rat hepatocytes by transmission and scanning electron microscopy

Summary Rexeptors for various lectins have been located on isolated hepatocytes by transmission and scanning electron microscopy, using gold markers of variable sizes. Quantitative data indicated that binding of some lectin markers depended upon their sizes.Acknowledgments. The authors thank Miss E. Bujard and Mr. A. Isely for the rat liver perfusion and Mrs M. Weber for the photographic work.     

Ciliated fibroblasts and smooth muscle cells in the rat uterus

Summary Ciliation in endometrial fibroblasts and myometrial muscle cells of the rat was examined by transmission electron microscopy. Quantification of the number of ciliated cells during the estrus cycle did not show any firm relationship between cilation and ovarian hormonal activity. In the case of most cilia, there is a spatial relationship between their basal centrioles and the Golgi complex, so that a Golgi-cilium complex is created. A possible role of ciliation in uterine fibroblasts and smooth muscle cells is discussed.     

ArF准分子激光晶化非晶硅薄膜微结构研究

利用ArF准分子激光对非晶硅薄膜的表层进行晶化后,采用拉曼光谱(Raman)、透射电镜(TEM)、场发射扫描电子显微镜(FE-SEM)等实验方法研究不同激光能量密度下晶化层硅薄膜微结构变化。实验结果表明:随激光能量密度的增大,薄膜结晶度增大,晶化层厚度加厚;晶粒尺寸则是先增大,直到激光能量密度增大到210 mJ/cm~2后,晶粒尺寸开始减小并且均匀性逐渐变差。最佳的激光能量密度范围为120～180 mJ/cm~2,这时薄膜表面晶化层晶粒比较均匀致密,薄膜质量较好。     

Effect of vasoactive amines on Weibel-Palade bodies in capillary endothelial cells

The presence and distribution of Weibel-Palade bodies in stomach and colonic mucosal microvessels after the administration of vasoactive amines (serotonin and histamine), the serotonin depletor reserpine, and the von Willebrand factor secretagogue thrombin, was studied by transmission electron microscopy. These agents elevated the number of Weibel-Palade bodies in all microvascular endothelial cells and especially in capillaries. It is concluded that vasoactive amines enhance the synthesis and secretion of large von Willebrand protein multimers by endothelial cells.     

Effect of vasoactive amines on Weibel-Palade bodies in capillary endothelial cells

The presence and distribution of Weibel-Palade bodies in stomach and colonic mucosal microvessels after the administration of vasoactive amines (serotonin and histamine), the serotonin depletor reserpine, and the von Willebrand factor secretagogue thrombin, was studied by transmission electron microscopy. These agents elevated the number of Weibel-Palade bodies in all microvascular endothelial cells and especially in capillaries. It is concluded that vasoactive amines enhance the synthesis and secretion of large von Willebrand protein multimers by endothelial cells.     

Microorganisms seen by scanning and transmission electron microscopy in Legionnaires' disease from human lung

Summary In addition to several anomalous structures, other general forms of definitely rod-shaped microorganisms have been found by scanning and transmission electron microscopy in the lung tissue taken at autopsy from a patient who succumbed to confirmed Legionnaires' disease with extensive necrotizing lobar pneumonia. The microorganisms were greatly varied in size and shape. They were micrographed in the act of fission. These forms have been found to some extent throughout the tissue. No nickel was demonstrated, either in the lung tissue or in the microorganisms.This work has been supported in part by a Henry Ford Hospital institutional grant from the Ford Foundation and in part by the Veterans Administration Medical Center Research Funds.     

Electron probe x-ray microanalysis and cryoultramicrotomy of unstained myocardial sarcoplasmic reticulum,in situ and fragmented

Summary Myocardial sarcoplasmic reticulum of cats in situ and fragmented sarcoplasmic reticulum (FSR) were analysed using X-ray microanalysis, cryoultramicrotomy and scanning transmission electron microscopy. 2 types of FSR vesicles can be distinguished morphologically and by their different elemental composition especially by different Ca loading. The Ca content of the sarcoplasmic reticulum can also be detected in situ.Acknowledgments. We thank Drs A.V. Somlyo and A.P. Somlyo for helpful advice and valuable discussion.This work was supported by the Deutsche Forschungsgemeinschaft.     

In vitro morphological characterization of the bursal reticuloepithelial (REp) cells of chicken

Summary The REp cells of the bursa follicle medulla of chicken were isolated in vitro. Culture of the REp cells was maintained over a period of 10 days and the cells were observed at 3 and 10 days by means of transmission electron microscopy (TEM) and immunofluorescence. The use of an anticytokeratin monoclonal antibody confirmed their epithelial nature. TEM observations showed the presence of desmonsomes and tonofilaments, which are characteristic of epithelial cells. Furthermore, to some extent the cells regenerated in vitro the network they form in vivo. Though the growth rate becomes slower with time, the features of the REp cells do not significantly change.