scholarly journals Hepatocyte innervation in primates.

1977 ◽  
Vol 74 (1) ◽  
pp. 299-313 ◽  
Author(s):  
W G Forssmann ◽  
S Ito

The efferent innervation and some characteristics of nerve fibers of the liver lobule in the tree shrew, a primate, are described. Nerve endings on hepatocytes were encountered regularly and were determined to be efferent adrenergic nerves. Transmission electron microscopy revealed nerve endings and varicosities in close apposition to the hepatocytes adjacent to the connective tissue of the triads as well as within the liver lobule in the space of Disse. Fluorescence microscopy indicated the existence of adrenergic nerves with a similar distribution. Autoradiography of the avid uptake of exogenous [3H]norepinephrine indicated that all intralobular nerves are potentially norepinephrinergic (adrenergic). Chemical sympathectomy with 6-OH-dopamine resulted in the degeneration of all intralobular liver nerve fibers as revealed by fluorescence microscopy and electron microscopy. Substantial regeneration occurred after 60-90 days but was not completed by that time. Some nerves were also observed in close association with von Kupffer cells and endothelial cells. The functional significance of the efferent liver innervation is discussed.

2010 ◽  
Vol 16 (2) ◽  
pp. 153-165 ◽  
Author(s):  
Samuel Clarke ◽  
Randall E. Mielke ◽  
Andrea Neal ◽  
Patricia Holden ◽  
Jay L. Nadeau

AbstractFew simple labeling methods exist for simultaneous fluorescence and electron microscopy of bacteria and biofilms. Here we describe the synthesis, characterization, and application of fluorescent nanoparticle quantum dot (QD) conjugates to target microbial species, including difficult to label Gram-negative strains. These QD conjugates impart contrast for both environmental scanning electron microscopy (ESEM) and fluorescence microscopy, permitting observation of living and fixed bacteria and biofilms. We apply these probes for studying biofilms extracted from perennial cold springs in the Canadian High Arctic, which is a particularly challenging system. In these biofilms, sulfur-metabolizing bacteria live in close association with unusual sulfur mineral formations. Following simple labeling protocols with the QD conjugates, we are able to image these organisms in fully-hydrated samples and visualize their relationship to the sulfur minerals using both ESEM and fluorescence microscopy. We then use scanning transmission electron microscopy to observe precipitated sulfur around individual cells and within the biofilm lattice. All combined, this information sheds light on the possible mechanisms of biofilm and mineral structure formation. These new QD conjugates and techniques are highly transferable to many other microbiological applications, especially those involving Gram-negative bacteria, and can be used for correlated fluorescence and electron microscopy.


1987 ◽  
Vol 96 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Takemoto Shin ◽  
Shun Watanabe ◽  
Shigeru Wada ◽  
Tadatsugu Maeyama

This study was conducted in order to investigate the structure of sensory nerve endings of the human epiglottis and substance P immunoreactive nerve fibers of the canine epiglottis in relationship to physiologic functions of the larynx. The human epiglottis was observed by light microscopy (silver impregnation) and electron microscopy, and the canine epiglottis was studied by peroxidase-anti-peroxidase (PAP) immunohistochemistry. The results are summarized as follows: (1) In the membranes of the epiglottis, we observed free endings of simple or complex tree shape, corpuscle endings with glomerular patterns, and taste-bud-like structures, and (2) electron microscopic studies revealed varicosity of the terminal axon with processes that contained small, clear and large, dense cored vesicles. Substance P was observed in these structures, and it was suggested that substance P was related to perception in the larynx.


Author(s):  
J. P. Brunschwig ◽  
R. M. McCombs ◽  
R. Mirkovic ◽  
M. Benyesh-Melnick

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.


Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.


1953 ◽  
Vol 98 (3) ◽  
pp. 269-276 ◽  
Author(s):  
E. De Robertis ◽  
C. M. Franchi

A technique has been developed for the extrusion of axon material from myelinated nerve fibers. This material is then compressed and prepared for observation with the electron microscope. All the stages of preparation and purification of the axon material can be checked microscopically and in the present paper they are illustrated with phase contrast photomicrographs. Observation with the electron microscope of the compressed axons showed the presence of the following components: granules, fibrils, and a membranous material. Only the larger granules could be seen with the ordinary microscope. A considerable number of dense granules were observed. Of these the largest resemble typical mitochondria of 250 mµ by 900 mµ. In addition rows or small clusters of dense granules ranging in diameter from 250 to 90 mµ were present. In several specimens fragments of a membrane 120 to 140 A thick and intimately connected with the axon were found. The entire axon appeared to be constituted of a large bundle of parallel tightly packed fibrils among which the granules are interspersed. The fibrils are of indefinite length and generally smooth. They are rather labile structures, less resistant in the rat than in the toad nerve. They varied between 100 and 400 A in diameter and in some cases disintegrated into very fine filaments (less than 100 A thick). The significance is discussed of the submicroscopic structures revealed by electron microscopy of the material prepared in the way described.


1974 ◽  
Vol 14 (2) ◽  
pp. 253-261
Author(s):  
J. JACOB ◽  
KATHERINE GILLIES ◽  
D. MACLEOD ◽  
K. W. JONES

The feasibility of in situ hybridization in tissue sections prepared for electron microscopy has been examined using mouse satellite DNA-complementary RNA and mouse L cells. The results obtained are encouraging, although certain technical aspects require further clarification. In interphase cells, hybrid-forming sites occur in chromatin patches positioned along the nuclear envelope. It is also confirmed that satellite DNA occurs in nucleolus-associated chromatin. The results suggest that satellite sequences are present in intranucleolar and peri-nucleolar chromatin. A similar distribution is indicated for ribosomal cistrons.


2021 ◽  
Vol 15 ◽  
Author(s):  
Gyeong Tae Kim ◽  
Sangkyu Bahn ◽  
Nari Kim ◽  
Joon Ho Choi ◽  
Jinseop S. Kim ◽  
...  

Critical determinants of synaptic functions include subcellular locations, input sources, and specific molecular characteristics. However, there is not yet a reliable and efficient method that can detect synapses. Electron microscopy is a gold-standard method to detect synapses due to its exceedingly high spatial resolution. However, it requires laborious and time-consuming sample preparation and lengthy imaging time with limited labeling methods. Recent advances in various fluorescence microscopy methods have highlighted fluorescence microscopy as a substitute for electron microscopy in reliable synapse detection in a large volume of neural circuits. In particular, array tomography has been verified as a useful tool for neural circuit reconstruction. To further improve array tomography, we developed a novel imaging method, called “structured illumination microscopy on the putative region of interest on ultrathin sections”, which enables efficient and accurate detection of synapses-of-interest. Briefly, based on low-magnification conventional fluorescence microscopy images, synapse candidacy was determined. Subsequently, the coordinates of the regions with candidate synapses were imaged using super-resolution structured illumination microscopy. Using this system, synapses from the high-order thalamic nucleus, the posterior medial nucleus in the barrel cortex were rapidly and accurately imaged.


1963 ◽  
Vol 39 (3) ◽  
pp. 39-53 ◽  
Author(s):  
Ryohei Honjin ◽  
Toshiki Kosaka ◽  
Ikuo Takano ◽  
Kyoichi Hiramatsu

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