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1.
Summary Untreated, decalcified and trypsinized acervuli from human pineal bodies were studied with the scanning and transmission electron microscope as well as by electron probe microanalysis. The mulberry-like acervuli are composed of a various number of spherical lobes (135–800 m) between which clustered groups of globuli (4–14 urn in diameter) are observed. The acervular lobes are very probably formed by an aggregation of these globuli. Small round particles 125–500 Å in diameter are observed on the surface of the pineal concretions. These are not influenced by either decalcification or trypsin treatment. The acervular mineral corresponds morphologically to hydroxyapatite. The electron probe microanalysis reveals the existence of calcium and phosphorus as main components of the acervuli. Small quantities of magnesium and strontium were also detected.Dedicated to Professor Berta Scharrer on the occasion of her 70th birthdayWith the technical assistance of Mr. P.A. MilliquetThe author wishes to thank Mr. Bauer and Mr. Fryder (Nestec SA, La Tour de Peilz) for the use of the Cambridge Stereoscan electron microscope and Dr. T. Jalanti (C.M.E., Lausanne) for his help with the use of the X-ray microanalyser  相似文献   

2.
Summary The lateral surfaces of heart muscle cells are interconnected by a varied and extensive network of structures that exist in addition to intercalated discs. Ultrastructural images of this network are vastly improved over those from epoxy-embedded material, particularly for low density components, through the application of a method for removing the embedding matrix from thin or thick sections that are then stereoscopically analyzed with standard or high voltage transmission electron microscopy. The connections include cables, 3–20 nm in diameter, multi-strand cables, 10–40 nm-granules, meshlike mats, and sheets, all extensively interwoven. It is suggested that intercellular connections of varying strength and distribution aid in the integration of mechanical performance of the large population of myocytes during the contractile cycle of the heart.This study was supported by a grant from NIH Biotechnology Resources through the University of Colorado High Voltage E.M. Laboratory, NIH Research Grant HL 24336, a N.Y. Heart Association Grant-in-Aid, and NIH Research Career Development Award HL 00568I thank Dr. E.H. Sonnenblick for continual aid and encouragement and Dr. R. Terry, Ms. Y. Kress, and Ms. J. Fant for use of facilities. I also thank Dr. K.R. Porter for guidance in the use of the HVEM technique, Dr. J.J. Wolosewick and Dr. M. Fotino for valuable suggestions, and Ms. J. Fleming, Mr. G. Wray, and Mr. G. Charlie of HVEM staff at Boulder. I acknowledge Dr. F. Pepe for use of facilities, Dr. R. Bloodgood for comments, and Mrs. L. Cohen-Gould, Ms. T. Downey, Mr. F. Reingold, Mrs. T. Maio, and Mrs. R. Shamoon for excellent assistance  相似文献   

3.
We report the development of a novel, multi-specimen imaging system for high-throughput transmission electron microscopy. Our cartridge-based loading system, called the "Gatling", permits the sequential examination of as many as 100 specimens in the microscope for room temperature electron microscopy using mechanisms for rapid and automated specimen exchange. The software for the operation of the Gatling and automated data acquisition has been implemented in an updated version of our in-house program AutoEM. In the current implementation of the system, the time required to deliver 95 specimens into the microscope and collect overview images from each is about 13 h. Regions of interest are identified from a low magnification atlas generation from each specimen and an unlimited number of higher magnifications images can be subsequently acquired from these regions using fully automated data acquisition procedures that can be controlled from a remote interface. We anticipate that the availability of the Gatling will greatly accelerate the speed of data acquisition for a variety of applications in biology, materials science, and nanotechnology that require rapid screening and image analysis of multiple specimens.  相似文献   

4.
Summary Single crystals from adult human peritubular dentine were studied by high-resolution transmission electron microscopy. Periodic fringe patterns were obtained from which the exact shape of the inorganic crystals were deduced. The crystals were found to have a mean length of 36.00±1.87 nm, a mean width of 25.57±1.37 nm, and a mean thickness of 9.76±0.69 nm. They consisted of platelets with a mean width-to-thickness ratio of 2.61, each being a flattened hexagonal prism of hydroxyapatite. Such conclusions are based upon a) the electron diffraction patterns that we obtained, and b) our comparison of the values of the periodic, equidistant fringes seen along different planes of sectioning with the corresponding theoretical values for hydroxyapatite.  相似文献   

5.
Comparative measurements of bacterial total counts and volumes of flow cytometry (FCM), transmission electron (TEM), and epifluorescence microscopy (EFM), were undertaken during a four week mesocosm experiment. Total counts of bacteria measured by TEM, EFM, and FCM were in the range of 1 · 106−6 cells ml−1, 1 · 106−3 · 1016 cells ml−1, and 5 · 105 cells ml−1 respectively. The mean volume of the bacterial community, measured by means of EFM and TEM, increased from 0.12–0.15 μm3 at the start of the experiment to 0.39–0.53 μm3 at the end. Generally, there was good agreement between the two methods and regression analyses gave r = 0.87 (p < < 0.01) for cell volume and r = 0.97 (p < < 0.01) for cell number. DAPI stained bacteria with volumes less than 0.2 μm3 were not detected by flow cytometry and these were generally an order of magnitude lower than counts made by TEM and EFM. For samples where the mean bacterial cell volume was longer than 0.3 μm3, all three methods were in agreement both with respect to counts and volume estimates.  相似文献   

6.
Modern cell biology is reliant on light and fluorescence microscopy for analysis of cells, tissues and protein localisation. However, these powerful techniques are ultimately limited in resolution by the wavelength of light. Electron microscopes offer much greater resolution due to the shorter effective wavelength of electrons, allowing direct imaging of sub-cellular architecture. The harsh environment of the electron microscope chamber and the properties of the electron beam have led to complex chemical and mechanical preparation techniques, which distance biological samples from their native state and complicate data interpretation. Here we describe recent advances in sample preparation and instrumentation, which push the boundaries of high-resolution imaging. Cryopreparation, cryoelectron microscopy and environmental scanning electron microscopy strive to image samples in near native state. Advances in correlative microscopy and markers enable high-resolution localisation of proteins. Innovation in microscope design has pushed the boundaries of resolution to atomic scale, whilst automatic acquisition of high-resolution electron microscopy data through large volumes is finally able to place ultrastructure in biological context.  相似文献   

7.
This study reports on morphological features of hepatic portal tracts in the liver of a rhesus monkey. The light microscope shows that the number of each type of principal component comprising a portal tract varies but that there are usually one to five lymphatics, one bile ductule, one bile duct, one arteriolar and one arterial branch of the hepatic artery, and one hepatic portal vein. Bile ductules, in cross section, have 6-10 cells (mostly low pyramidal, but with a few cuboidal) bordering the lumen, an outside diameter of from about 20 to 25 microm, and a luminal diameter of from 2 to 10 microm. Bile ducts, in cross section, have more than 10 cells (about equal numbers of low pyramidal and cuboidal) bordering the lumen, an outside diameter greater than 25 microm and a luminal diameter of greater than 10 microm. The term "pyramidal" has not previously been applied to the cells of the ductules and ducts. The monkey tracts show several cytological features previously undescribed, viz., abortive cilia and basal bodies in the duct cells, abortive cilia in the ductule cells, and an occasional aggregation of ribosomes in arterial endothelial cells. They also show a major histological feature previously mentioned but not illustrated, viz., bundles of nerve processes which exhibit a preferential location, i.e., proximity to the arterioles and arteries.  相似文献   

8.
Morphological features of osteoclasts derived from a co-culture system   总被引:1,自引:0,他引:1  
The interaction between the receptor activator of NfKB (RANK) and its ligand receptor activator of NfKB ligand (RANKL) has recently been proven to be pivotal for osteoclast differentiation and activation. The influence of RANK-RANKL signaling on osteoclast formation was established by co-culturing murine osteoblasts (type CRL-12257) and murine mononuclear monocytes (RAW 264.7). The aim of the present study was to examine, by means of morphological techniques, the interaction between these two cell lines grown in the absolute absence of exogenous cytokines and other stimulating factors. Moreover, we wanted to show that our model could provide a system to analyze the bone resorption process. Mineralized matrix induced morphological changes of osteoclasts (OC) by the formation of organized ruffled-border and a large number of secondary lysosomal vesicles. On the contrary, OC grown on glass coverslips without dentin showed no organized ruffled border or secondary lysosomes. The study of the relationship between these two cell types could establish new approaches for a potential pharmacological control of these cell types and tissues in health and disease.  相似文献   

9.
Summary The scanning electron microscope has been used to investigate the surfaces of epidermis, hair follicles, fat cells, glands and blood vessels in sections of human skin. The appearances of structures associated with these surfaces have been described. The results demonstrate that this new instrument can become an important tool in the investigation of surface changes that might accompany the application of loads (extensive, compressive or torsional), or physiological or pathological abnormalities.We wish to thank Prof. R. M. Kenedi for his continued encouragement of this work. One of us (I.A.B.) is also grateful to the Science Research Council for the provision of a post-graduate student grant.  相似文献   

10.
11.
杨啸  赵奎军  王克勤  韩岚岚  杨帅 《昆虫知识》2012,49(5):1321-1326
利用扫描电镜观察了大豆食心虫Leguminivora glycinivorella Matsumura成虫的触角感器的形态和分布。结果表明,大豆食心虫成虫触角呈线型,感器包括毛型感器、耳型感器、刺型感器、腔锥型感器、栓锥形感器、鳞型感器和Bhm氏鬃毛,共7种。雌雄个体之间触角感器的分布特点基本相同,但是种类、数量有差异,存在性二型现象。  相似文献   

12.
Summary The papilla basilaris of scincid lizards is relatively long, slightly curved or bowed, and characteristically has an apical terminal expansion. A limbus-attached tectorial membrane is present but is apparently not continuous with the tectorial material covering the hair cells of the papilla. The hair cells of the apical expansion are covered by a thick spongy mass of tectorial material, while the hair cells above (dorsal to) the apical region are covered by thickened tectorial material that is in the form of uniquely sculptured, twisted or folded drape-like masses (sallets). The surface of the basal (dorsal) quarter of the papilla is unusual in that it is concave rather than convex. The expanded terminals of the hair cell kinocilia are also unusual in being arrowhead-shaped.Kinocilial orientation of the non-apical papillary hair cells is simply bidirectional; the hair cells on each side of the papillary axial midline are oriented toward the midline. Kinocilial orientation of the hair cells of the apical expansion is more complex with the peripheral neural and abneural rows both being abneurally directed, and the central rows being at first neural in orientation, but becoming abneurally oriented as the apical tip is approached. At the apical tip region, most all hair cells are abneurally oriented.I would like to thank Ms Maria Maglio for her skill in handling the technical aspects of the electron microscope, Mr. David Akers for expert photographic assistance, and Ms. Michiko Kasahara for aid in all aspects of the work. Research sponsored by United States Public Health Service Grant NS-09231.  相似文献   

13.
麻疯树柄细蛾触角及其感器的扫描电镜观察   总被引:4,自引:0,他引:4  
江南  李庆  周建华  肖银波 《昆虫知识》2010,47(2):355-359
应用扫描电镜对麻疯树柄细蛾Stomphastis thraustica Meyrick成虫触角的外部形态结构及其感器进行了观察和研究。结果表明,麻疯树柄细蛾成虫触角上存在着5种感器即毛形感器、刺形感器、腔椎形感器、锥形感器和鳞形感器。对各种感器的形态特点进行描述,其中毛形感器数量最多,并分为长毛形和短毛形2种。刺形感器也分为长刺形和短刺形2种。  相似文献   

14.
The water concentration in biological cells plays a predominant role in cellular life. Using electron energy loss spectroscopy, the feasibility to measure the water content in cells has already been demonstrated. In this paper, we present an upgrade of water measurement in hydrated cryosections by spectrum imaging mode in a medium-voltage scanning transmission electron microscope. The electron energy loss spectra are recorded in spectrum imaging mode in a 2n×2n pixels array. Each spectrum is processed in order to determine the water mass content in the corresponding pixel. Then a parametric image is obtained in which grey levels are related to water concentration. In this image, it is possible to recognize the different subcellular compartments. By averaging the water concentration over the relevant pixels, we can determine the water mass content in the concerned subcellular compartment. As an example, we present water mass content measurement at subcellular level in rat hepatocytes.  相似文献   

15.
Charge contrast imaging (CCI) is a dynamic phenomenon recently reported in insulating and semiconducting materials imaged with low vacuum or variable pressure scanning electron microscopes (SEM). Data presented in this paper illustrates that CCI can also be applied to biominerals and biological soft-tissues and that useful and unique structural information can be obtained from routine samples. Various resin-embedded samples were considered and example images from several different biomaterials are presented. Due to the diverse nature of samples that appear to exhibit charge contrast, this imaging technique has prospective application in a wide range of biological and biomedical research. This work represents the first application of CCI to biomaterials and in particular, highlights a new method for investigating the formation, structure and growth of biominerals.  相似文献   

16.
Accurate image alignment is needed for computing three-dimensional reconstructions from transmission electron microscope tilt series. So far, the best results have been obtained by using colloidal gold beads as fiducial markers. If their use has not been possible for some reason, the only option has been the automatic cross-correlation-based registration methods. However, the latter methods are inaccurate and, as we will show, inappropriate for the whole problem. Conversely, we propose a novel method that uses the actual 3D motion model but works without any fiducial markers in the images. The method is based on matching and tracking some interest points of the intensity surface by first solving the underlying geometrical constraint of consecutive images in the tilt series. The results show that our method is near the gold marker alignment in the level of accuracy and hence opens the way for new opportunities in the analysis of electron tomography reconstructions, especially when markers cannot be used.  相似文献   

17.
    
The effects of various handling procedures used in preparing specimens of human and pig respiratory mucosa for scanning electron microscopy (SEM) were studied. Using five different washing methods, the percentage area of mucosa covered with extracellular material varied from 1.5 to 53.1%. The best results were achieved when specimens were washed by gently inverting a sample 30 times in a container filled with physiological saline. Fixation and drying of the surface layer caused disorientation of cilia and made examination difficult. Mechanical damage caused loss of cilia and rupture of the cell membrane. For SEM of respiratory cilia it is important to wash the specimen in saline before fixation and to use biopsy forceps as little as possible.  相似文献   

18.
Summary The perfused large mesenteric lymph node of the dog was observed under the scanning electron microscope.The lymph sinus contains reticulum cells which mostly are two-dimensionally formed stellate plates oriented in a uniform direction. Large round macrophages are loosely fixed by the reticulum cell processes. No intermediate type between both cells has been observed. Macrophages having a few long tentacle-like projections are densely covered by clubbed cytoplasmic processes. Smaller round cells, probably plasma cells and lymphocytes also remained in the sinus.The pulp of the node is built up by reticulum cells, much smaller than those in the sinus, and by densely packed round cells including a few macrophages.The trabeculae and the reticulum of the nodal parenchyme form a continuous structure.Cordial thanks are expressed to Dr. Toshihiro Ishii, Professor of Anatomy of the Tohoku University Medical School, for his valuable advice. Thanks are also due to the kind cooperation of Mr. Akira Kubotsu of the Central Research Laboratories, Kuraray Co. Ltd.  相似文献   

19.
应用扫描电镜对瘤胫厕蝇Fannia scalaris(Fabricius)成虫触角的外部形态结构及其感受器进行了观察和研究.结果表明,瘤胫厕蝇成虫触角上存在着2类感受器:毛形感受器和锥形感受器,其中毛形感受器数量最多,分为5种.对各种感受器的形态特点进行了描述.  相似文献   

20.
The histology of the digestive tract of the amberjack ( Seriola dumerili , Risso) was studied using light and scanning electron microscopy. The anterior oesophagus mucosa displays primary and secondary folds lined with a stratified squamous epithelium with fingerprint-like microridges which is substituted, on the top of the oesogaster folds, by a simple columnar epithelium with short microvilli. Only primary folds are present in the stomach. The anterior portion is rich in simple tubular glands, whereas the oesogaster and the pyloric region are devoid of them. Pyloric caeca and anterior and middle intestine mucosa display the same pattern of folding. The dominant cell type is the enterocyte, which exhibits larger and thinner microvilli in the caeca than in the intestine. The columnar epithelium of the rectum is replaced, in the anal sphincter, by a stratified flattened epithelium. Goblet cells are numerous throughout the whole length of the tract with the exception of the initial part of the oesophagus, the oesogaster, the stomach and the anal sphincter. Mucosubstances have been shown to vary in the different regions of the gut: acid mucines are found in the oesophagus, pyloric stomach, caeca, intestine and rectum, whereas neutral mucosubstances dominate in the anterior portion of the stomach. The muscularis is well developed throughout the length of the tract: two layers of striated muscle at the oesophageal level; two layers of smooth muscle in the stomach wall and three at the intestinal level.  相似文献   

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