scholarly journals STAINED PECTIN AS SEEN IN THE ELECTRON MICROSCOPE

1960 ◽  
Vol 8 (2) ◽  
pp. 501-506 ◽  
Author(s):  
Peter Albersheim ◽  
K. Mühlethaler ◽  
A. Frey-Wyssling
Keyword(s):  
Middle Lamella ◽  
Water Soluble ◽  
Hot Water ◽  
Residual Fraction ◽  
Young Plant ◽  
Pectic Substance ◽  
Electron Microscopic ◽  
Dense Deposits ◽  
Longitudinal Wall ◽  
Microscopic Studies

This paper describes electron microscopic studies on the distribution of pectin within young plant cells. Dark-grown onion roots, from 1 to 3 mm. in length, were used. In order to make the pectic substances selectively dense to electrons, they were first reacted with basic hydroxylamine. This treatment produces pectic hydroxamic acids, which in turn were treated with ferric ion to form insoluble complexes. The tissue was imbedded, sectioned, and then observed by electron microscopy. Dense deposits of iron were found in the region of the middle lamella and in a second area near the surface of the primary wall. Transverse walls of varying maturity were noted. The pectin of the more frequent, immature cross-walls, leads directly into the inner reacting layer of the axillary (longitudinal) wall. The pectin of the more mature transverse walls becomes, on the other hand, intimately associated with the middle lamella pectin of the axillary wall. It is shown that the pectin of the middle lamella represents the hot water-soluble portion of the pectic substance, while the internal layer of the axillary wall and the transverse wall pectin represent the so called residual fraction. Hot versene extraction removes essentially all electron-dense material.

scholarly journals Improvements of glycol methacrylate. I. Its use as an embedding medium for electron microscopic studies.

1977 ◽  
Vol 25 (3) ◽  
pp. 163-174 ◽  
Author(s):  
R C Spaur ◽  
G C Moriarty
Keyword(s):  
Electron Beam ◽  
Water Soluble ◽  
Cross Linking ◽  
Electron Microscopic ◽  
Glycol Methacrylate ◽  
Ultrastructural Studies ◽  
Tissue Morphology ◽  
Methacrylate Monomer ◽  
Microscopic Studies ◽  
Embedding Medium

The technique for using the water-soluble embedding medium glycol methacrylate has been improved for ultrastructural studies by the simplification of the method of formation of prepolymers used in embedding the tissue, by the addition of a cross-linking agent so that sections are stable in the electron beam, and by improving the softness of the blocks by the addition of a plasticizing agent. The preservation of tissue morphology has been improved by complete dehydration in glycol methacrylate monomer prior to infiltration with the prepolymer. Preservations of tissue morphology is further enhanced by complete dehydration in ethanols and embedding in the improved glycol methacrylate medium.

scholarly journals Complex character of the influence of polycarboxylic and phosphonic acids on the crystallization of calcium and magnesium salts in dynamic conditions

2021 ◽  
Vol 65 (2) ◽  
pp. 168-177
Author(s):  
E. V. Vorobieva ◽  
A. D. Vorobiev ◽  
I. V. Shestak ◽  
D. V. Cherednichenko ◽  
S. V. Bucha
Keyword(s):  
Induction Period ◽  
Phase Formation ◽  
Water Soluble ◽  
Electron Microscopic ◽  
Phosphonic Acids ◽  
Dynamic Conditions ◽  
Influence Of Water ◽  
Microscopic Studies ◽  
Magnesium Salts ◽  
Calcium And Magnesium

The influence of water-soluble organic compounds (adipic, polyaspartic and phosphonic acids) and their compositions on the crystallization of calcium and magnesium salts in dynamic conditions has been studied. It is found that the induction period of phase formation increases in the presence of polyaspartic and phosphonic acids 2.3–5.2 times in the range of their content from 0.05 to 0.2 ppm. The results of XRD and electron microscopic studies confirm the change in the phase composition and morphology of the crystalline precipitate that is formed. The dibasic carboxylic acid influence on the induction period, composition and structure of the precipitate is much less. It is established that the composition of organic acids also increases the induction period of phase formation. The complex inhibitor provides an increase in the critical supersaturation level in the system. The phosphonic and carboxyl groups of the inhibitor interact with calcium and magnesium ions and block the crystallization nuclei. When interacting with the dicarboxylic acid and polyacid adsorption on the surface of the formed crystals, the microcrystals dissolve.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

Electron Microscopic identification of Pre-B Lymphocytes in the Bone Marrow of a Patient with Chronic Myelocytic Leukemic in Blast Crisis

1982 ◽  
Vol 40 ◽  
pp. 346-347
Author(s):  
T. Mullin ◽  
G. Yee ◽  
M. Aheam ◽  
J. Trujillo
Keyword(s):  
Blast Crisis ◽  
Immunoglobulin M ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Transformation Theory ◽  
Electron Microscopic ◽  
Chemotherapeutic Sensitivity ◽  
Microscopic Studies ◽  
Hematopoietic Precursor ◽  
Lymphoblastic Transformation ◽  
B Lineage

There have been numerous reports in the current literature suggesting that hematopoietic precursor cells in some human chronic myelocytic leukemias (CML) undergo lymphoblastic transformation at the time of the acute blast crisis (BC) stage. The primary evidence offered in support of this transformation theory--lymphoblastic appearing morphology, increased terminal deoxynucleotidyl transferase (TdT) activity, and chemotherapeutic sensitivity to vincristine and prednisone--has been indirect, however, since these features may occur in nonlymphoid cells. More direct support for the Pre-B lineage of these cells has recently been provided by immunofluorescent light microscopic studies demonstrating the presence of intracytoplasmic immunoglobulin M (IgM) in these CML-BC cells.

Origin of Hepatic Nuclear Inclusion Bodies

1973 ◽  
Vol 31 ◽  
pp. 426-427
Author(s):  
F. G. Zaki ◽  
J. A. Greenlee ◽  
C. H. Keysser
Keyword(s):  
Inclusion Bodies ◽  
Storage Disease ◽  
Glycogen Storage ◽  
Nutritional Deficiencies ◽  
Nuclear Inclusion ◽  
Electron Microscopic ◽  
Human Liver Cells ◽  
Microscopic Studies ◽  
Per Se ◽  
Experimental Liver

Nuclear inclusion bodies seen in human liver cells may appear in light microscopy as deposits of fat or glycogen resulting from various diseases such as diabetes, hepatitis, cholestasis or glycogen storage disease. These deposits have been also encountered in experimental liver injury and in our animals subjected to nutritional deficiencies, drug intoxication and hepatocarcinogens. Sometimes these deposits fail to demonstrate the presence of fat or glycogen and show PAS negative reaction. Such deposits are considered as viral products.Electron microscopic studies of these nuclei revealed that such inclusion bodies were not products of the nucleus per se but were mere segments of endoplasmic reticulum trapped inside invaginating nuclei (Fig. 1-3).

Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

1991 ◽  
Vol 49 ◽  
pp. 34-35 ◽  
Author(s):  
P. Frayssinet ◽  
J. Hanker ◽  
D. Hardy ◽  
B. Giammara
Keyword(s):  
Hip Prosthesis ◽  
Ethanol Concentration ◽  
Bone Matrix ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Hip Prostheses ◽  
Cellular Inclusions ◽  
Microscopic Studies ◽  
Diamond Saw ◽  
Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

Dendritic cells of the human epidermis: immuno-electron microscopic studies of la antigen reactivity

1978 ◽  
Vol 36 (2) ◽  
pp. 644-645
Author(s):  
G. Rowden ◽  
M. G. Lewis ◽  
T. M. Phillips
Keyword(s):  
Dendritic Cells ◽  
Langerhans Cells ◽  
Cell Types ◽  
Cell Type ◽  
Electron Microscopic ◽  
La Antigen ◽  
Microscopic Studies ◽  
A Cell ◽  
C3 Receptors ◽  
Antigen Reactivity

Langerhans cells of mammalian stratified squamous epithelial have proven to be an enigma since their discovery in 1868. These dendritic suprabasal cells have been considered as related to melanocytes either as effete cells, or as post divisional products. Although grafting experiments seemed to demonstrate the independence of the cell types, much confusion still exists. The presence in the epidermis of a cell type with morphological features seemingly shared by melanocytes and Langerhans cells has been especially troublesome. This so called "indeterminate", or " -dendritic cell" lacks both Langerhans cells granules and melanosomes, yet it is clearly not a keratinocyte. Suggestions have been made that it is related to either Langerhans cells or melanocyte. Recent studies have unequivocally demonstrated that Langerhans cells are independent cells with immune function. They display Fc and C3 receptors on their surface as well as la (immune region associated) antigens.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Cytoplasmic Invaginations in Trophoblasts and Epithelial Cells of Rat

1971 ◽  
Vol 29 ◽  
pp. 524-525
Author(s):  
Iracema M. Baccarini
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Nuclear Inclusions ◽  
Mucous Cells ◽  
Electron Microscopic ◽  
Cervical Epithelium ◽  
Intact Membrane ◽  
Microscopic Studies ◽  
Abnormal Cells ◽  
Nuclear Features

Some morphological nuclear features (invaginations) in normal and abnormal cells have been described in several electron microscopic studies. They have been referred to by others as blebs, loops, pockets, sheets, bodies, nuclear inclusions and cytoplasmic invaginations. Identical appearing structures were found in cells of the uterine cervical epithelium, in trophoblasts of blastocysts and in trophoblasts of rat placenta.Methods. Uterine cervix (normal rats), rat placenta (9-10 days gestation) and blastocyst were placed in 3% glutarahdehyde for 3 hours. The tissue was washed in phosphate buffer for 24 hours, postfixed in 1%. buffered osmium tetroxide for 1-2 hours and embedded in epon araldite. Sections were double stained with uranyl acetate and lead citrate and viewed in E. M. Siemens 200.Observations. Nuclear invaginations were found in basal, parabasal and mucous cells of the cervix epithelium, in trophoblasts of blastocyst and in trophoblasts of placenta. An oval, round or elongated invagination contained heterogenously cytoplasm surrounded by a double intact membrane; usually several invaginations were found in the same nucleus.

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