An Electron Microscopic study of the liver in certain marine teleosts

1990 ◽  
Vol 48 (3) ◽  
pp. 510-511
Author(s):  
V.E.C. Ooi ◽  
Linda S.M. Ooi ◽  
Shuyi Ma
Keyword(s):  
Pancreatic Tissue ◽  
Hepatic Tissue ◽  
Lates Calcarifer ◽  
Electron Microscopic ◽  
Hepatic Parenchyma ◽  
Transmission Electron ◽  
Architectural Organization ◽  
Parenchymal Cells ◽  
Siganus Javus ◽  
Lutjanus Bohar

The hepatic parenchyma of five marine teleosts (belonging to five families in the Teleostei) was investiga ted during the summer months by means of light and transmission electron microscopy. The architectural organization of the livers of these teleosts displays remarkable differences with regard to the interrelationship with the pancreatic tissue. In Lates calcarifer and Lutjanus bohar, prominent pancreatic tissue is found in the liver, following the course of portal vein and hepatic artery and surrounding the branches of these vessels. The pancreatic tissue appears less abundant in Mylio macrocephalus than in the preceding species. In Siganus javus and Gymnothorax schismatorhynchus, there are no dispersed intrahepatic pancreas. The liver lobules are defined by the presence of connective tissue strands in Lates and Siganus, but in the other three species there was no precise lobulation of the hepatic tissue.The microstructure of the livers in these teleosts is basically the same in all cases, although there are considerable variations inultrastructure of their parenchymal cells. The plates of hepatocytes which are usually two or more cells thick is in terrupted by sinusoids lined with fenestrated endothelial cells and Kupffer cells (Figs. 1, 2).

Haemorrhagic nephritis and enteritis of geese: Pathomorphological investigations and proposed pathogenesis

2005 ◽  
Vol 53 (2) ◽  
pp. 213-223 ◽  
Author(s):  
M. Dobos-Kovács ◽  
E. Horváth ◽  
A. Farsang ◽  
Edith Nagy ◽  
Andrea Kovács ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
The Body ◽  
Tissue Homogenate ◽  
New Disease ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Parenchymal Cells ◽  
Functional Deficiency

Haemorrhagic nephritis and enteritis of geese as a new disease was first described in Hungary in 1969. The authors identified the causative agent of the outbreaks occurring in 1969 as a polyomavirus by PCR in 2001. In order to study the pathogenesis of the virus, one-day-old goslings were infected with tissue homogenate that tested positive for polyomavirus by PCR. Morphological, light and transmission electron microscopic (TEM) examinations have revealed that goose haemorrhagic polyomavirus replicates in the endothelial cells of the blood vessels and capillaries of diseased birds. Infection causes damage and necrosis of the endothelial cells. The virus was not observed in the parenchymal cells. Oedema and haemorrhages found throughout the body may be due to the dysfunction or functional deficiency of endothelial cells damaged by the virus.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

An electron microscopic study of the intra-myocardial lesions in cases of acute myocardial infarction

1978 ◽  
Vol 36 (2) ◽  
pp. 484-485
Author(s):  
Masahiro Ono ◽  
Kaoru Aihara ◽  
Gompachi Yajima
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Coronary Vessels ◽  
Vascular Wall ◽  
Vascular Changes ◽  
Electron Microscopic ◽  
Main Trunk ◽  
Mechanical Destruction ◽  
Transmission Electron ◽  
Myocardial Lesions

The pathogenesis of the arteriosclerosis in the acute myocardial infarction is the matter of the extensive survey with the transmission electron microscopy in experimental and clinical materials. In the previous communication,the authors have clarified that the two types of the coronary vascular changes could exist. The first category is the case in which we had failed to observe no occlusive changes of the coronary vessels which eventually form the myocardial infarction. The next category is the case in which occlusive -thrombotic changes are observed in which the myocardial infarction will be taken placed as the final event. The authors incline to designate the former category as the non-occlusive-non thrombotic lesions. The most important findings in both cases are the “mechanical destruction of the vascular wall and imbibition of the serous component” which are most frequently observed at the proximal portion of the coronary main trunk.

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

Studies of Circular DNA Using a New Electron Microscopic Technique

1973 ◽  
Vol 31 ◽  
pp. 596-597
Author(s):  
C. N. Gordon
Keyword(s):  
Electron Microscopy ◽  
Aqueous Salt Solution ◽  
Contour Length ◽  
Cleavage Surface ◽  
Mica Substrate ◽  
Electron Microscopic ◽  
Replica Technique ◽  
Circular Dna ◽  
Transmission Electron ◽  
Electron Microscopic Technique

Gordon and Kleinschmidt have described a new preparative technique for visualizing DNA by electron microscopy. This procedure, which is a modification of Hall's “mica substrate technique”, consists of the following steps: (a) K+ ions on the cleavage surface of native mica are exchanged for Al3+ ions by ion exchange. (b) The mica, with Al3+ in the exchange sites on the surface, is placed in a dilute aqueous salt solution of DNA for several minutes; during this period DNA becomes adsorbed on the surface. (c) The mica with adsorbed DNA is removed from the DNA solution, rinsed, dried and visualized for transmission electron microscopy by Hall's platinum pre-shadow replica technique.In previous studies of circular DNA by this technique, most of the molecules seen were either broken to linears or extensively tangled; in general, it was not possible to obtain suitably large samples of open extended molecules for contour length measurements.

Determination of the phase structure of polymerblends by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 492-493
Author(s):  
Dr. G. Kaemof
Keyword(s):  
Screw Extruder ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Single Screw Extruder ◽  
Transmission Electron ◽  
The Matrix ◽  
Twin Screw ◽  
Special Case ◽  
Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

The blister of porphyria cutanea tarda: A Scanning and Transmission Electron Microscopic study

1986 ◽  
Vol 44 ◽  
pp. 334-335
Author(s):  
Veronika Burmeister ◽  
R. Swaminathan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Middle Age ◽  
Porphyria Cutanea Tarda ◽  
Minor Trauma ◽  
Electron Microscopic ◽  
Transmission Electron Microscopic Study ◽  
Transmission Electron ◽  
Transmission Electron Microscopic

Porphyria cutanea tarda (PCT) is a disorder of porphyrin metabolism which occurs most often during middle age. The disease is characterized by excessive production of uroporphyrin which causes photosensitivity and skin eruptions on hands and arms, due to minor trauma and exposure to sunlight. The pathology of the blister is well known, being subepidermal with epidermodermal separation, it is not always absolutely clear, whether the basal lamina is attached to the epidermis or the dermis. The purpose of our investigation was to study the attachment of the basement membrane in the blister by comparing scanning with transmission electron microscopy.

A transmission electron microscopic study of structural transitions in fast ionic conductors

1987 ◽  
Vol 45 ◽  
pp. 156-157
Author(s):  
R. B. Queenan ◽  
P. K. Davies
Keyword(s):  
Optical Properties ◽  
Ionic Conduction ◽  
Recent Observation ◽  
Ionic Conductivities ◽  
Sodium Aluminate ◽  
Two Dimensions ◽  
Ionic Conductors ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Trivalent Cations

Na ß“-alumina (Na1.67Mg67Al10.33O17) is a non-stoichiometric sodium aluminate which exhibits fast ionic conduction of the Na+ ions in two dimensions. The Na+ ions can be exchanged with a variety of mono-, di-, and trivalent cations. The resulting exchanged materials also show high ionic conductivities.Considerable interest in the Na+-Nd3+-ß“-aluminas has been generated as a result of the recent observation of lasing in the pulsed and cw modes. A recent TEM investigation on a 100% exchanged Nd ß“-alumina sample found evidence for the intergrowth of two different structure types. Microdiffraction revealed an ordered phase coexisting with an apparently disordered phase, in which the cations are completely randomized in two dimensions. If an order-disorder transition is present then the cooling rates would be expected to affect the microstructures of these materials which may in turn affect the optical properties. The purpose of this work was to investigate the affect of thermal treatments upon the micro-structural and optical properties of these materials.

Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

1990 ◽  
Vol 48 (3) ◽  
pp. 222-223
Author(s):  
T. Shimizu ◽  
Y. Muranaka ◽  
I. Ohta ◽  
N. Honda
Keyword(s):  
Clinical Manifestations ◽  
Quadriceps Muscle ◽  
Honeycomb Structure ◽  
Periodic Paralysis ◽  
Ultrastructural Changes ◽  
Hypokalemic Periodic Paralysis ◽  
Electron Microscopic ◽  
Tubular Aggregates ◽  
Hypokalemic Myopathy ◽  
Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

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