scholarly journals RNA SYNTHESIS IN RAT AND MOUSE HEPATIC CELLS AS STUDIED WITH LIGHT AND ELECTRON MICROSCOPE RADIOAUTOGRAPHY

1966 ◽  
Vol 30 (3) ◽  
pp. 655-660 ◽  
Author(s):  
N. J. A. Noorduyn ◽  
J. C. H. de Man
Keyword(s):  
Electron Microscope ◽  
Rna Synthesis ◽  
Hepatic Cells

scholarly journals THE DISORGANIZATION OF HEPATIC CELL NUCLEOLI INDUCED BY ETHIONINE AND ITS REVERSAL BY ADENINE

1968 ◽  
Vol 36 (2) ◽  
pp. 313-328 ◽  
Author(s):  
Hisashi Shinozuka ◽  
Peter J. Goldblatt ◽  
Emmanuel Farber
Keyword(s):  
Electron Microscope ◽  
Nuclear Membrane ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Hepatic Cell ◽  
Short Term ◽  
Hepatic Cells ◽  
Basic Reaction ◽  
Reaction Patterns

The structure of nuclei and nucleoli of hepatic cells after short-term ethionine administration was investigated with the electron microscope. By 1½ hr after the injection, a distinct alteration occurred in the nucleoli which was characterized by the appearance of electron-opaque masses in the nucleolonema. After 6–8 hr, the nucleoli showed partial fragmentation into small, dense masses. Large aggregates of interchromatinic granules appeared in the nucleoplasm. Condensation of chromatin became prominent in the nucleoplasm particularly along the nuclear membrane. By 12 hr almost complete fragmentation of nucleoli had occurred. The administration of adenine or methionine at 4 hr prevented the development of nucleolar changes. Also, adenine administration at 8 hr after ethionine completely reversed the nucleolar lesion by 12 hr. After methionine administration at 8 hr, many nucleoli showed incomplete reconstruction with many twisted ropelike structures when viewed 4 hr later. Identical structures were found when adenine was given at 8 hr, and animals were sacrificed 2 hr later. On the basis of this observation, the simplified structures of nucleoli found 2 hr after adenine or 4 hr after methionine appeared to be precursors of the nucleolonema. It is suggested that nucleoli show at least two basic reaction patterns to inhibitors of RNA synthesis, one typified by actinomycin D and one by ethionine.

scholarly journals THE USE OF SILVER NITRATE AS A VITAL STAIN, AND ITS DISTRIBUTION IN SEVERAL MAMMALIAN TISSUES AS STUDIED WITH THE ELECTRON MICROSCOPE

1955 ◽  
Vol 1 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Edward W. Dempsey ◽  
George B. Wislocki
Keyword(s):  
Electron Microscope ◽  
Silver Nitrate ◽  
Chronic Administration ◽  
Pancreatic Acinar Cell ◽  
Basement Membranes ◽  
Metallic Silver ◽  
Hepatic Cells ◽  
Kidney Liver ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

After chronic administration of a dilute solution of silver nitrate in drinking water to rats, mice, and guinea pigs, granular deposits of metallic silver were detected in electron micrographs of the kidney, liver, thyroid, and pancreas. The silver deposits were in the form of extremely dense, angular particles with sharp outlines. They varied from aggregates a few microns in diameter down to granules at the limit of resolution of the electron microscope. The principal sites of deposition were (1) basement membranes, especially those of the renal glomeruli, proximal convoluted tubules, and various glands, and those associated with vascular endothelium, and (2) the cytoplasm of fixed and free macrophages. Both in Kupffer cells lining hepatic sinusoids and in the wandering macrophages of other tissues, the silver was segregated in discrete vacuoles. In addition, granular deposits were observed in occasional vesicular structures in the proximal convoluted tubules of the kidney, the hepatic cells, and the pancreatic acinar cell. These structures, in favorable preparations, contained an outer double layered membrane and internal folds similar to those of mitochondria, from which they appear to have been derived. The significance of these findings in heavy metal poisoning and in cellular physiology is briefly discussed.

scholarly journals LIGHT AND ELECTRON MICROSCOPIC RADIOAUTOGRAPHY OF HEPATIC CELL NUCLEOLI IN MICE TREATED WITH ACTINOMYCIN D

1967 ◽  
Vol 33 (3) ◽  
pp. 489-496 ◽  
Author(s):  
J. C. H. de Man ◽  
N. J. A. Noorduyn
Keyword(s):  
Orotic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Electron Microscopic ◽  
Granular Component ◽  
Hepatic Cells ◽  
Progressive Loss ◽  
Nucleolar Rna ◽  
Silver Grains ◽  
Electron Microscopic Radioautography

Nucleolar partition induced by actinomycin D was used to demonstrate some aspects of nucleolar RNA synthesis and release in mouse hepatic cells, with light and electron microscopic radioautography. The effect of the drug on RNA synthesis and nucleolar morphology was studied when actinomycin D treatment preceded labeling with tritiated orotic acid. Nucleolar partition, consisting of a segegration into granular and fibrillar parts was visible if a dosage of 25 µg of actinomycin D was used, but nucleolar RNA was still synthesized. After a dosage of 400 µg of actinomycin D, nucleolar RNA synthesis was completely stopped If labeling with tritiated orotic acid preceded treatment with 400 µg of actinomycin D, labeled nucleolar RNA was present 15 min after actinomycin D treatment while high resolution radioautography showed an association of silver grains with the granular component. At 30 min after actinomicyn D treatment all labeling was lost. Since labeling was associated with the granular component the progressive loss of label as a result of actinomycin D treatment indicated a release of nucleolar granules. The correlation between this release and the loss of 28S RNA from actinomycin D treated nucleoli as described in the literature is discussed.

scholarly journals THE FINE STRUCTURAL LOCALIZATION OF GLUCOSE-6-PHOSPHATASE IN RAT LIVER

1962 ◽  
Vol 10 (6) ◽  
pp. 754-762 ◽  
Author(s):  
LOIS W. TICE ◽  
RUSSELL J. BARRNETT
Keyword(s):  
Endoplasmic Reticulum ◽  
Enzyme Activity ◽  
Plasma Membrane ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Phosphatase Activity ◽  
Rat Liver ◽  
Structural Localization ◽  
Hepatic Cells ◽  
Fixed Material

Glucose-6-phosphatase activity was demonstrated histochemically in rat liver using either the Wachstein-Meisel medium or a modified Chiquoine medium, and the characteristic properties of the enzyme activity were confirmed. The distribution of activity in both unfixed and hydroxyadipaldehyde-fixed material was demonstrated with the electron microscope. Activity was found in both smooth- and rough-surfaced elements of the endoplasmic reticulum of hepatic cells, including the nuclear envelope, but was absent from the plasma membrane. These findings further implicate the endoplasmic reticulum as an organelle of transport, and in addition suggest that the nuclear envelope has functional as well as morphological continuity with the endoplasmic reticulum.

Nuclear pore number changes in Sertoli cells at different stages of the spermatogenic cycle

1990 ◽  
Vol 48 (3) ◽  
pp. 76-77
Author(s):  
Juan C. Cavicchia ◽  
Alfonsina Morales
Keyword(s):  
Electron Microscope ◽  
Sertoli Cells ◽  
Rna Synthesis ◽  
Albino Rats ◽  
Nuclear Pore ◽  
Pore Density ◽  
Nuclear Pores ◽  
Cacodylate Buffer ◽  
Dynamic Structures ◽  
Pore Number

Sertoli cell population is not functionally homogeneous along the spermatogenic cycle of the seminiferous epithelium. The maximal binding of 125 I-FSH by Sertoli cells was found at stages XIII-I where as mode rate binding occurs at stages IX-XII. Also important physiological events take place in the first mentioned stages like meiotic divisions and the initiation of RNA synthesis in haploid cells. As nuclear pores are dynamic structures whose number varies according with the cellular metabolic requirementsys we explored the nuclear pore density in Sertoli cells in stages XIII-I versus stages IX-XII. Albino rats were used. Both sets of stages were recognized and isolated by transillumination under a dissecting microscope (stages XIII-I with weak spots and IX-XII with pale absorption). Tubular segments were fixed in glutaralde-hyde-cacodylate buffer, immersed in 30% glycerol, freeze-fractured in a Balzers BAF 301 apparatus at-110°C and examined under a Seimens Elmiskope I electron microscope.

Electron Cytochemical Study of Carbon Dioxide Laser Effect on Rhesus Monkey Cornea

1974 ◽  
Vol 32 ◽  
pp. 224-225
Author(s):  
K. C. Tsou ◽  
J. Morris ◽  
P. Shawaluk ◽  
B. Stuck ◽  
E. Beatrice
Keyword(s):  
Carbon Dioxide ◽  
Electron Microscope ◽  
Rhesus Monkey ◽  
Carbon Dioxide Laser ◽  
Cytochemical Study ◽  
Laser Effect

While much is known regarding the effect of lasers on the retina, little study has been done on the effect of lasers on cornea, because of the limitation of the size of the material. Using a combination of electron microscope and several newly developed cytochemical methods, the effect of laser can now be studied on eye for the purpose of correlating functional and morphological damage. The present paper illustrates such study with CO2 laser on Rhesus monkey.

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.

Utilizing Dark Field Electron Microscopy to Produce Lantern Slides

1974 ◽  
Vol 32 ◽  
pp. 116-117
Author(s):  
J. N. Meador ◽  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Electron Microscope ◽  
Electron Micrographs ◽  
Dark Field ◽  
Limiting Factor ◽  
Clinical Laboratories ◽  
Field Electron ◽  
Time Element ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Dark Field Micrographs

The electron microscope is being utilized more and more in clinical laboratories for pathologic diagnosis. One of the major problems in the utilization of the electron microscope for diagnostic purposes is the time element involved. Recent experimentation with rapid embedding has shown that this long phase of the process can be greatly shortened. In rush cases the making of projection slides can be eliminated by taking dark field electron micrographs which show up as a positive ready for use. The major limiting factor for use of dark field micrographs is resolution. However, for conference purposes electron micrographs are usually taken at 2.500X to 8.000X. At these low magnifications the resolution obtained is quite acceptable.

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