bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporation of computer-assisted analytical diagnostic electron microscopy in clinical pathology—a critical technical assessment
Authors: Hirohata Yasuhisa , Aihara Kaoru , Suzuki Katsuya , Hata Toshio , Kurokawa Taneomi , Son Teijun
Published: June 2020

Purpose: It is generally accepted that the incorporation of the transmi ssion and scanning electron microscopy is very virsatile in giving informations for diagnostic and therapeutic purposes.However,in the view point that the electron microscopy usually require very pain taking procedures for tissue preparation and limitation in the sizes of observation, there are admittingly existing some controversy if this could stand for the standard technology in medical investigative methods. In this sense, lack of quantitative or culumative electron microscopic methodology should be responsible to some extent. For establishing the standarized methodology for diagnostic biological electron microscopy, the laboratories has been undertaken an extensive survey for analytical diagnostic electron microscopy in virtue of the computer-assisted statistical methodology. The present investigation is dealing with the trial technological assessment of this systematized methodology.

Materials and methods:

The materials: Various types of the biopsied materials of kidney, liver and inherited metabolic diseases or tumorous conditions have been used for the investigation. However, for simplication and modulation or simulated study only the kidney diseases are discussed in this series of investigation.
Deposition and fabrication of specimen by means of ion beam sputtering
Authors: Hojou Kiichi , Kimura Toshiaki , Adachi Koichi , Kishi Shinichi , Arakawa Noboru , Kanaya Koichi
Published: June 2020

The apparatus used in the experiment consists of a modified duoplasma- tron source in which the ion beam with 1-20 kV is collimated and focused by an electrostatic lens onto the target.

For deposition purposes as when shadowing or coating a specimen, the beam of atoms emerging from the target with about 10 eV energy, is collimated by means of 0.5-1.0 mm slit in a metal shield placed close to the specimen. The shadowing angle ø can be varied from about 10-90° with the vacuum chamber at 10-6 Torr. Secondary electrons emitted from the target are trapped by a potential applied to the collimating slit. Usually the target is cooled by water.
Cis-dichloro-diammine platinum (II): a stain for electron microscopic preparations
Authors: Heinen Ernst
Published: June 2020

We have previously reported that cis-dichloro-diammine platinum (II) (cis-Pt), an antimitotic agent discovered by Rosenberg and coworkers, can be used to contrast ultrathin sections. It was interesting to tend to increase the contrast given by this cis-Pt staining and to establish to which radicals cis-Pt binds in the cell.

We have analysed various cell types (fibroblasts and Ehrlich tumour cells cultivated in vitro or various tissues : liver, pancreas, heart muscle, epididyme, intestine, etc.) fixed in glutaraldehyde, embedded in Epon and stained by immersion in a cis-Pt solution (1 mg/ml, 37°C, 2 or 3 days, in darkness).

In all cases chromatin, especially heterochromatin, presents a very high contrast after cis-Pt staining and can easily be distinguished from the nucleolus (fig.). In the cytoplasm only ribosomes are well contrasted. The other organites are generally poorly stained, in some mitochondria, dense granules or filaments are apparent. Secretory granules containing proteins or mucopolysaccharides (basigranular or goblet cells of the intestine, mastocytes, pancreatic cells, etc.) are faintly stained by cis-Pt. In the heart muscle actin and myosin are only poorly contrasted. Cis-Pt suits thus for contrasting nucleic acids especially for differentiating DNA from RNA containing structures.
Ultrastructural details as revealed by stereo transmission electron microscopy of high resolution, pre-shadowed surface snd freeze-etch replicas: sample— the drosophila eye
Authors: Steere Russell L.
Published: June 2020

Whereas SEM is useful for studying the surface of objects such as an insect eye at relatively low magnifications, TEM of pre-shadowed replicas has advantages for visualization of the ultrastructural details of surfaces, and freeze-fractured, or freeze-etched specimens.

For surface replica studies, fruit flies (Drosophila melanogaster) were glued with glycerol onto a solid copper cap which was then placed on the stage of the Denton freezeetch module. Specimens were frozen by flowing liquid nitrogen into the specimen tube. When specimen temperature reached -105°C, the chamber was evacuated and the shroud cooled to -196°C. With a vacuum of 5 x 10-6 mm Hg, the specimen was warmed to -95°C for 3 to 5 minutes to allow sublimation of any ice which might have condensed on its surface. Specimen temperature was then lowered to -150°C and specimen was shadowed with Pt and coated with carbon.
Particle clustering in secretory granule membranes induced by centrifugation: freeze-fracture analysis using different cryofixations
Authors: Schuler G. , Plattner H. , Aberer W. , Winkler H.
Published: June 2020

Bovine chromaffin granules (BCG) were isolated by the method of sucrose density gradient centrifugation. Subsequently they were resuspended in isotonic (a) calcium-magnesium-free phosphate-buffered saline (CMF-PBS) pH 7, (b) CMF-PBS + sucrose, (c) Tris-Cl buffer + NaCl or (d) sucrose. Processing for freeze-fracturing was done without prefixation or antifreeze treatments in the following ways: (A) BCG were processes as a su spension which was pipetted onto golden Balzers specimen supports (“standard” freezing); (B) aliquots were frozen in suspension with much higher cooling rates using “spray-freezing” (Bachmann et al. 1972); (C) other samples were re-centrifuged (12,000 g x 25 min) and mounted with a spatula on Balzers supports as firm pellets, i.e. without stirring during sample transfer. Samples (A, C) on Balzers holders were “standard” frozen by dipping into liquid Freon 22; propane was used for spray-freezing.
Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy
Authors: Stöffler G. , Bald R.W. , Dieckhoff J. , Eckhard H. , Lührmann R. , Tesche B. , Tischendorf G.W.
Published: June 2020

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.

The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).
Molecular weight and ultrastructure of an oligomeric and a small monomeric protein molecule determined in the stem
Authors: Engel A. , van Driel R.
Published: June 2020

We have used our STEM (Vacuum Generators HB-5) and digital data acquisition and display system to explore the experimental limits of electron microscopic MW determination of macromolecules. Two proteins have been used as test objects: (i) protein P23, which is the major structural protein of the phage T4 head precursor and has a MW of 58k daltons. P23 has been isolated as described elsewhere. Over a broad range of conditions P23 occurs in an oligomeric state, sedimenting at 11 S (van Driel, unpublished). (ii) Herring sperm protamine (protamine sulfate from Mann Res. Lab., New York), which has previously been used for exploring the limits of conventional and scanning darkfield electron microscopy on biological specimens; it has a MW of 4.2k daltons.

P23 oligomers (0.3 mg/ml) in 0.1 M phosphate, pH7, were fixed in glutaraldehyde and dialized against distilled water. Protamine sulfate (0.1 mg/ml) was dissolved in distilled water. The proteins were absorbed on hydrophilic 2 nm thin carbon films.
Protamine-DNA interaction
Authors: Bazett-Jones D.P. , Ottensmeyer F.P.
Published: June 2020

Dark field electron microscopy has been used for the study of the structure of individual macromolecules with a resolution to at least the 5Å level. The use of this technique has been extended to the investigation of structure of interacting molecules, particularly the interaction between DNA and fish protamine, a class of basic nuclear proteins of molecular weight 4,000 daltons.

Protamine, which is synthesized during spermatogenesis, binds to chromatin, displaces the somatic histones and wraps up the DNA to fit into the small volume of the sperm head. It has been proposed that protamine, existing as an extended polypeptide, winds around the minor groove of the DNA double helix, with protamine's positively-charged arginines lining up with the negatively-charged phosphates of DNA. However, viewing protamine as an extended protein is inconsistent with the results obtained in our laboratory.
Visualization of native chromatin fibers in different embedding media
Authors: Muñoz-Guerra Sebastian , Subirana Juan A.
Published: June 2020

The influence of the embedding medium is of critical importance in the observation of nucleoprotein structures in thin sections. The use of conventional epoxi media requires dehydratation, impregnation and subsequent polymerization, which may produce drastic alterations in the fine structure of chromatin. The use of water soluble embedding media may lead to improvements in the preservation of ultrastructure. In this paper we explore the differences which may be detected in nucleohistone fibers embedded in different media.

Spermatozoa from Holothuria polii were subjected to moderate lysis in either 0.15M NaCl, ImM Tris-HCl, 0.4mM CaCl2, pH 8.0 (a) or 0.25M sucrose, 0.4mM CaCl2 (b) and then fixed by addition of 2 % glutaralde- hyde. Embedding was carried out as described in the literature in the following media: araldite-epon mixture (AREPO), glycol methacrylate (GMA, 1), hydroxipropyl methacrylate (HPMA, 2) and bovine serum albumin (BSA, 3) or histones.
Observation of DNA by negative staining: phage t7 DNA-capsid complexes
Authors: Serwer Philip
Published: June 2020

A technique has been developed for observing extended nucleic acids in specimens negatively stained with uranyl acetate. This technique has been used to characterize bacteriophage T7 DNA-capsid complexes obtained by: a) disruption of T7 phage using glutaraldehyde treatment; b) isolation from Xysates of bacteriophage T7-infected E. coli. The latter complexes may be in the DNA packaging pathway of T7.

A sample of circular, duplex bacteriophage ØX174 DNA (.2 μg/ml) in. 1 M NaCl,
.01 M Tris-Cl,. 001 M EDTA, pH 7.4, was mixed with an equal volume of cytochrome c (200 μg/ml) and was incubated for five minutes. This mixture was incubated with a carbon-coated grid for one minute; the grid was washed and was negatively stained with 1% uranyl acetate. An accumulation of negative stain around the DNA-bound cytochrome c reveals the presence of DNA circles (Figure 1). The cytochrome c bound to DNA is observed as an electron transparent region, 40-65 Å in diameter, within the negative stain.
Microtubules in optic nerves of temperature acclimated goldfish
Authors: Matheson D.F. , Diocee M.S. , Hussain S.T. , Roots B.I.
Published: June 2020

The phenomenon of “fast axonal transport” whereby macromolecules and other material are transported rapidly down the axon has been extensively documented. Structural candidates which have been considered to be responsible for facilitating this fast axonal transport include mitochondria, microtubules and possibly neurofilaments. Few attempts have been made to define these structural entities quantitatively. This is particularly true for the goldfish optic system, a system for which much biochemical data on axonal transport exists.

Goldfish were acclimated to 5° and 25°C for one month on a 12 h dark 12 h light photoperiod. Optic nerves were fixed in situ with 4% glutaraldehyde in either EGTA and PIPES or Millonig's phosphate buffer for 2 min, excised and immersed in fresh fixative for 24 h. They were post-fixed in 1% osmium tetroxide in the appropriate buffer for 1 1/2 h, dehydrated with ethanol and embedded in Spurr's medium.
On the ultrastructural localization of cell surface sialyl residues versus anionic sites
Authors: Skutelsky E. , Hoglund S. , Morein B. , Bayer E.A.
Published: June 2020

Membrane-associated sialic acids(SA) are considered to have an important role in a variety of cell sur ace interactions. Visualization of SA sites and their ultrastructural quantitative evaluation have heverally been based on the coulombic interaction between anionic sites of sialyl carboxyl groups with polycationic,electron dense markers, e.g. colloidal ferric hydroxide or cationized ferritin(CF). We have recently demonstrated an alternative method, whereby periodate-induced biotinylation (PIB) of unfixed cells can be used for specific localization of SA in thin sections by ferritin-conjugated avidin (FAv). It was further shown that PIB does not affect the surface anionic charge, since the latter is still available to CF-staining. In order to determine the role of anionic sites on the distribution and configuration of cell surface sialoglycoproteins and or sialoglycolipids, we have compared the topographic distribution of attached FAv or CF particles on normal and pathological blood cells,following successive treatment with sodium periodate and biotin hydrazide.
Detection of glycoconjugates by lectins and glycosylated ferritin in the ciliary membrane of the quail oviduct
Authors: Sandoz Daniel , Boisvieux-Ulrich Emmanuelle , Chailley Bernadette
Published: June 2020

The freeze-fractures of ciliary membrane show very few intramembrane particles except'for the ciliary necklace, located at the base of the organelle, which is composed of several sinuous arrays of particles (Fig.a). In the quail oviduct, it is also possible to distinguish these particles in thin sections, they appear as beads on the external surface of the ciliary membrane (Fig.b).

Glycosylated ferritin allows the detection with a good resolution of the lectin binding sites of the plasma membrane.

Pieces of quail oviduct (magnum) were incubated, after glutaralde- hyde fixation,either with Concanavaline A (major affinity : mannosyl or glucosyl residues), or wheat germ lectin (WGA)(major affinity : N-acetyl- glucosamine or N-acety1-neuraminic acid residues). The bound Con A molecules were visualized by Mannosyl-Ferritin. Control specimens were incubated directly with Mannosyl-Ferritin without prior incubation with Con A or with Con A in presence of 0-methyl-α -D-mannosyl-pyranoside.
Cell membrane permeability defects demonstrated with colloidal lanthanum early in ischemic cell injury in dog heart
Authors: Haskins H.K. , Sharov V.G. , Jennings R.B.
Published: June 2020

Lanthanum hydoxide, an electron-dense colloid with a nominal average particle size of 20 A, has been used for many years to label the extracellular space as a tracer applied during aldehyde fixation. If ischemic cell injury were to produce large defects in the sarcolemma, lanthanum would be expected to enter the cell. We studied the distribution of various preparations of lanthanum in thin free-hand slices of dog posterior papillary muscle after 0, 15, 40 or 240 minutes of severe ischemia caused by surgical occlusion of the circumflex coronary artery. Cell death regularly develops after 40 or more minutes of severe ischemia. Ionic lanthanum, lanthanum hydroxide according to Revel and Karnovsky and lanthanum silicate were used with and without pretreatment with alcian blue. Best results were obtained with freshly made solutions of La (NO)3 titrated carefully to pH 7.8, to prepare a clear fixative approximately 1% in lanthanum and 4%, in buffered glutaraldehyde.
Tight junction assembly in human adenocarcinoma cell line: relations to cytoskeletal elements
Authors: Polak-Charcon Sylvie , Ben-Shaul Yehuda
Published: June 2020

Human colon adenocarcinoma cell line HT29 was found to be a favorable system for the study of junctions assembly. Using scanning electron microscopy (SEM), thin sectioning (TEM) and freeze fracturing, we were able to demonstrate that HT29 cells grown to confluency have desmosomes but clearly lack tight or gap junctions. When treated with trypsin, cells were rounded up, made contacts, and within 15 min formed tight and gap junctions. The desmosomes, however, were split to hemi-desmosomes. These findings agree with results obtained for other experimental systems.

In this work we have used cytochalasin B (CB), colchicine (C) and CB + C, drugs known to interfere with microfilaments and microtubules, in order to determine to what extent these structures are involved with the assembly of tight junctions in HT29 cells treated with trypsin. The drugs were added to confluent monolayered cells (CB:20 μg/ml - 1 h; C: 10-4 M - 3 h; CB:20 μg/ml + C: 10-4 M/ml - 3 h), then trypsin was added to a final concentration of 0. 25% for 15 min.
Structure of the macromolecular surface arrays on the bacteriumsporosarcina urea: isolation, purification, and reassembly
Authors: Beveridge T. J.
Published: June 2020

Sporosarcina ureais a unique bacterium that grows under alkaline conditions which would normally limit bacterial viability. It possesses a gram-positive wall which contains little phosphate, suggestive that teichoic polymers are absent, and a surface layer (Fig. 1A) which exhibited a predilection for heavy metal stains in thin section (Fig. 1B). Negative stains (Fig. 2) and freeze-etchings of this layer demonstrated it to be composed of a macromolecular tetragonal array (C-C = 120Å) and when these images were subjected to optical diffraction, substructure at ca. 15 Å was revealed (Fig. 3). This layer was sensitive to more acid conditions (pH ⋜6. 0) which negated the use of high contrasting agents such as uranyl acetate.

Isolation of this regularly structured (RS) layer was accomplished by shearing a suspension of the bacteria (in 0. 05 M HEPES buffer pH 8. 2) in a French pressure cell and harvesting the wall fragments by centrifugation. Sequential treatment with 2% Triton X - 100 and 100 μg lysozyme per ml resulted in the solubilization of adherent plasma membrane and digestion of the wall proper.
Chemical modification of the bacterial wall to determine sites of metal deposition
Authors: Beveridge T. J.
Published: June 2020

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.

Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.
Immune electron microscopic study of interactions between measles virus nucleocapsids and antibodies from sera of patients with SSPE
Authors: Cohen-Forterre L. , Rousset S. , Lebon P.
Published: June 2020

Subacute sclerosing panencephalitis(SSPE)is a progressive degenerative disease of the central nervous system. This disease is generally associated with a chronic infection with measles virus. If measles virus is clearly involved however additional factors must determine the onset of SSPE. Hall and Ter Meulen reported that if “all the genetic information of measles virus is contained in SSPE virus, the latter apparently contain an additional 10% information”. They thought that “if a recombination occurs with another second virus, then it is with the intact genome of measles virus and a defective genome of the second virus ”. Previously Lebon et al. report ed the presence in sera/from patients with SSPE of antibodies able to precipitate an antigen of canine distemper virus. Antibodies of this type have not been detected inhuman sera with confirmed measles antibodies.
Ultrastructural studies of an aquatic bacterium, seliberia stellata
Authors: Swafford J. R. , Schmidt J. M.
Published: June 2020

Seliberia stellata is a bacterium first isolated from tundra soil and described as a spirally twisted rod having one subpolar flagellum and reproducing by fission or budding. The cells stick at their poles forming a rosette or star form. Although this procaryotic organism has been noted in aquatic environments such as fresh water ponds and laboratory distilled water, strains from these habitats have apparently not been obtained in pure culture. We have isolated the bacteria from two fresh water sources and maintained them as pure cultures in dilute peptone-yeast extract broth or 1% agar media.

Isolation of two strains of these organisms was achieved by enriching water samples with 0. 005% peptone. Enrichment culture surfaces were evaluated for the presence of bacteria by placing carbon-stabilized formvar grids onto the unbroken surface film followed by immediate removal and staining with 0. 25 or 0. 5% potassium phosphotungstate for TEM. The occurrence of Seliberia-like cells in these enrichments was rare (approximately 1/1000).
Freeze substitution for ion localisation studies
Authors: Wilson A. J.
Published: June 2020

The radial pathways by which water and various solutes are transported across plant roots have not yet been clearly delineated. A number of investigations have been made into one possible alternative, - the apoplastic continuum, - which can be regarded morphologically as the entire cell wall complex together with the xylem vessels. These have been carried out using ions or molecules with a low toxicity at low concentration, and a high electron scattering capacity, such as lanthanum or uranyl salts. Some of these investigations have indicated that the tracer never crosses the plasmalemma into the cytolasm, while at least one other has found lanthanum and uranyl tracers in the cytoplasm, albeit as an included form in membrane-bound vesicles, (possibly endocytotic). Clearly, good ultrastructural preservation of the tissue is essential in such an investigation, for a clear understanding of the process by which the tracer may be transported into the cell.
An ultrastructural study of vegetative incompatibility in plants
Authors: Moore Randy
Published: June 2020

Cell and tissue interactions are a basic aspect of eukaryotic growth and development. While cell-to-cell interactions involving recognition and incompatibility have been studied extensively in animals, there is no known antigen-antibody reaction in plants and the recognition mechanisms operating in plant grafts have been virtually neglected.

An ultrastructural study of the Sedum telephoides/Solanum pennellii graft was undertaken to define possible mechanisms of plant graft incompatibility. Grafts were surgically dissected from greenhouse grown plants at various times over 1-4 weeks and prepared for EM employing variations in the standard fixation and embedding procedure. Stock and scion adhere within 6 days after grafting. Following progressive cell senescence in both Sedum and Solanum, the graft interface appears as a band of 8-11 crushed cells after 2 weeks (Fig. 1, I). Trapped between the buckled cell walls are densely staining cytoplasmic remnants and residual starch grains, an initial product of wound reactions in plants.
Ultrastructural study of the early development of the gregarine parasite grebneckiella nixellae misra
Authors: Dass C. M. S. , Singotam L.
Published: June 2020

Eugregarines, amongst all the sporozoans are unique in that the trophozoite shows the differentiation of the body into three distinct zones a. epimerite, b. protomerite and c. deutomerite. G. pixellae. which is a parasite in the midgut of the common centipede Scolopendra marsitans. is a typical example of eugregarines and was used in this study to trace the ultrastructural features of the various zones of the trophozoite as well as the development of these structures during the early (intra-cellular) part of the life cycle.

Sporozoite which is released from the spore in the midgut of the host, has an ellipsoid shape and a very simple organization. The body, enveloped by a typical plasma membrane, contains a centrally placed nucleus, a few mitochondria and a large number of electron dense granules. The sporozoites make their way into the epithelial cells lining the midgut and start intracellular development. The sporozoite become oval and increase in size.
Distribution of cationic tracer substances in kidney capillary wall in experimental immunocomplex diseases
Authors: Kerjaschki D. , Förster O. , Boltz G. , Scheiner W. , Albini B.
Published: June 2020

Negatively charged macromolecules constitute a part of the barrier imposed by the kidney glomerular capillary wall to proteins larger than MW 70 000. Charged groups are present within the basement membrane (BM), and the surface coats of both endothelial and especially epithelial cells. By various electron dense cationic tracer substances, (lysocyme, cationic ferritin (cat. F), protamin sulfate) a reticular pattern of tracer granules is visualized in the lamina rara externa (LRE) of the BM. In experimental immunocomplex diseases (autologous Heymann-nephritis, chronic BSA-induced serum sickness) immunoglobulin containing deposits form in the LRE, and the BM becomes permeable to albumin (i. e. proteinuric). Since reduction of polianions in the capillary wall is sometimes paralleled by proteinuria (Puromycin-nephrosis, late phase of Heymann-nephritis), we study their distribution at an ultrastructural level in Heymann-nephritis and chronic serum sickness by the use of policationic ferritin (cat. F, MW 460 000, IP 8, 7), cationic horse radish peroxidase (cat. HRP, MW 40 000, IP 10, 3), and cationic cytochrome C (cat. CC, MW 14 OOO, IP 11).
Electron microscopic radioautographic study of glycoprotein biosynthesis and renewal in the renal glomeruli of the rat
Authors: Haddad A. , Lachat J-J. , Gonçalves R. P.
Published: June 2020

Biosynthesis, migration and renewal of glycoproteins were studied by radioautography in the renal glomeruli after administering L-3H-fucose to rats which were killed at several time intervals after injection, by perfusion of glutaraldehyde through the abdominal aorta. Small pieces of the kidney were post fixed in 0s04, dehydrated and embedded in Epon 812. Semithin and thin sections of the renal cortex were processed for light and electron microscopic radioautography, respectively. At the light microscope level (Fig. 1) it was observed that the main site of incorporation of 3H-fucose into glycoproteins was the paranuclear region of the visceral epithelial cells (podocytes). Weak paranuclear radioautographic reactions were also observed in endothelial and mesangial cells at 10 minutes after injection. At the longer time intervals these paranuclear reactions disappeared and the silver grains were mostly overlying the several components of the capillary wall. Silver grain counts showed that the peak of the silver grain density over the glomeruli occurred at 4 hours after injection; by 14 days the radioautographic reactions were almost negligible.
An ultrastructural study of the pathogenesis of the arteriosclerotic lesions in the spontaneous hypertensive (SHR) rat strain
Authors: Yajima G. , Kurihara S. , Ida M. , Aihara K. , Asano G. , Sohn T. J. , Kwon H. Y.
Published: June 2020

The spontaneous hypertensive rats are the strain which was isolated by Okamoto et al and is known to cause high frequency of spontaneous hypertension in later stage of life. Some of them are also recongnized to have high frequency of the cerebro-vascular accident and is also designated as apoplexy prone strain. The genetic and etiological factors of this spontaneous hypertension are the matters of the extensive survey of the investigators, however, the morphological aspects of this specific strain of causing the hypertension still await further confirmation in future. In this viewpoint, the authors have undertaken the electron microscopic and cytochemical electron microscopic studies of the various arteries in a rather extensive manner.

The spontaneous hypertensive rats were supplied from the animal room of the University of Kyoto by courtesy of Drs. Okamoto and Yamori. The rats were kept on the commericially available solid diet and sytolic blood pressure was measured and scored daily.
Electronmicroscopic and biochemical studies on surfactant of fetal newborn and adult rat lungs
Authors: Yasuda Hiromoto , Toida Suzuko , Kosakai Mamoru , Ueda Nobuo , Takahashi Ichiro
Published: June 2020

Materials and methods:

Pulmonary surfactant from lung homogenates of fetal, newborn and adult S. D. strain rats, prepared using differential and discontinuous density gradient of Nacl solution(Katyal, et. al., 1977), were fixed with 2. 5% glutal aldehyde with 2% tannic acid (Kalina, M., et. al. 1977), for 2 hours and post-fixed with 1% OsO4 solution for 2 hours.

The other part of surfactant of same materials fixed with 2. 5% glutal aldehyde, added with 30% glyserol for prevention of ice crystal formation, were chilled by liquid nitrogen and placed in the HUS-5GB with block type freeze-fracture apparatus.

Thin film of carbon replicae were made with shadowed by Pt. and Pd., mounted on copper grids. Lung tissues prepared for usual electron microscope studies were in one part, embedded in Epon 812, and, the others, also made thin film of carbon replica for freeze-fracture study. Surfactant from lung homogenates, and lung tissues prepared for usual electronmicroscopic studies were dehydrated by gradual alcohol series, embedded in Epon 812, sectioned by MT-2(Porter type), or Reichert type ultramicrotomes, mounted on copper grids, and stained with uranyl acetate and lead citrate.
Phagocytosis of particles by alveolar macrophages
Authors: Chao J. , Tausch J. , Biggar W. D. , Sturgess J. M.
Published: June 2020

The alveolar macrophage plays a key role in pulmonary defense. It functions in the clearance of particles from the peripheral lung, although the cellular mechanisms and factors which influence its function are poorly understood. In the lung, macrophages vary in size and distribution in peripheral airways and in the alveoli where they are closely associated with the alveolar wall.

The mechanism of phagocytosis has been investigated with rat alveolar macrophages in vitro, comparing two different particle types: a large particle (zymosan) and a smaller, bacterial particle (Staphylococcus aureus). Alveolar macrophages were isolated from rat lung by bronchial lavage and incubated in vitro in two culture systems: one with cells in suspension and one with cells adherent to a glass substrate. The cells were then challenged with non-opsonised or opsonised particles for various time intervals. The interaction of particles with the cell surface, their ingestion and, for bacterial particles, killing was examined, correlated and quantitated by scanning and transmission electron microscopy and by bacteriological assays.
Cytological criteria for a histogenetic classification of bronchogenic carcinomas
Authors: Hess Frederick G.
Published: June 2020

Although pulmonary cytology has been quite successful in the diagnosis of well differentiated epidermoid carcinomas (wdEC) and well differentiated adenocarcinomas, cytological accuracy is very poor for various forms of poorly differentiated epidermoid carcinomas (pdEC) and poorly differentiated adenocarcinomas (pdAC) as well as large cell carcinomas (LCC), giant cell carcinomas (GCC), and undifferentiated carcinomas (UC). Using routine light microscopic descriptions based mainly upon cellular form and size, human and hamster pulmonary tumors have been previously classified illogically, with little reference to their histogenesis. A new classification of lung carcinomas, based upon cell of origin, utilizes specific morphological features of various tumor types at the cellular level. Ultrastructural and histochemical techniques reveal that the majority of lung tumors are derived from mucous and/or basal cells. Studies in our laboratories on the histogenesis of epidermoid metaplasia, carcinoma in situ, and regeneration have shown the transformation of mucous cells to nonkeratinizing squamous metaplastic cells which may undergo keratinization.
Ultrastructural localization of carbonic anhydrase in mouse gastric parietal cells
Authors: Sugai N. , Ito S.
Published: June 2020

The histochemical localization of carbonic anhydrase in parietal cells has been described by a number of investigators and its presence in these cells at the ultrastructural level has been also reported. However the precise distribution of this enzyme is not clear and there are some questions regarding the validity of the histochemical reaction. In the present study, various modifications of the technique were explored and it was found that tissues fixed in buffered formaldehyde, glutaraldehyde with trinitrocresol or picric acid retained good reaction product localization of this enzyme. Cryostat sections of the fixed tissues were treated with solutions recommended by Hannson. Incubation times that were most favorable 5 to 10 min for light microscopy and 8 to 15 min for electron microscopy. For ultrastructural observations of thin sections, it was found to be important that the reacted tissue sections were post osmicated with 1% osmium tetroxide in 1. 5% potassium ferrocyanide or with aqueous 1% 0s04 for only 3 to 5 min.
Giardia lamblia in human duodenum and bile
Authors: Watson J. H. L. , Goodwin J. , Rajan K. S.
Published: June 2020

The increasing frequency of sporadic Giardia lamblia in the human population of the Detroit metropolitan area has provided unexpected opportunity for scanning electron microscopy of the trophozoite in its natural human environment. Sixty-five cases of giardiasis have been diagnosed here in the last four years. The bile and duodenal biopsies of ten of these were studied by light microscopy. In addition, three of the biopsies were processed for scanning electron microscopy not only to determine ultrastructural details of the protozoan itself and of the duodenal surface in giardiasis but to study the possible mechanisms of the infestation as it acts to interfere with the intenstinal absorption process. Two normal duodenal biopsies were studied as controls. Small biopsy samples of duodenum were fixed immediately for electron microscopy in cacodylate buffered 2. 5% glutaraldehyde. After fixation these were dehydrated in graded ethanols, passed through amyl acetate and critical point dried with CO2.
Fine structure of human sperm entry into zona-free hamster oocyte
Authors: Barros C. , González J. , Herrera E. , Bustos-Obregón E.
Published: June 2020

Zona-free mammalian oocytes have been observed to fuse, under in vitro conditions, With non-homologous spermatozoa. Taking advantage of this heterologous gamete fusion, we designed a bioassay to test -by means of zona-free hamster oocytes- the fertile ability of human spermatozoa, from semen samples of patients attending an Infertility Clinic. To further validate our bioassay, which Was reported elsewhere, we studied the behavior of gamete membranes during fusion at the ultrastructural level.

Zona-free hamster oocytes were mixed in vitro with human spermatozoa. At different times after the start of incubation, oocytes were fixed in 1% glutaraldehyde in 0. 25M cacodylate buffer pH 7. A and post-fixed in 196 osmium tetroxide. After dehydration in acetone, they were embedded in a low viscosity epoxy resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Phillips 300 electron microscope.
Types of intercellular junctions in teleost ovarian follicles (plecoglossus altivelis)
Authors: Toshimori K. , Ōura C , Yasuzumi F
Published: June 2020

In animal ovarian follicles, many investigators have reported various types of intercellular junctions such as desmosome (macula adherens), gap junction (nexus) and tight junction (zonula occludens). Between adjacent follicle cells, though both desmosomes and gap junctions were clearly presented, no tight junctions were ellucidated by electron microscope excepting Adams and Hertig (guinea pig;1964) and Espey and Stutts (rabbit;1972). On the other hand, between the oocyte and follicle cells, though desmosmes or desmosome-like areas were shown, no gap junctions were recognized to exist excepting Amsterdam et al. (1976) who suggested the presence of small gap junctions on rat oocyte surfaces and Anderson and Albertini (1976) who showed the presence of aggregations of intramembraneous particles on the oocyte surfaces in mouse, rat, rabbit and monkey. Types of intercellular junctions in animal ovarian follicles were not completely understood, because few workers applied freeze-fracture technique to demonstrate junctions excepting Anderson and Albertini (1976).
Characterization of mammary cells from the lactating rat by electron microscopy
Authors: Sadhukhan P. , Chakraborty J. , Soloff M. S. , Wieder M. H. , Senitzer D.
Published: June 2020

The means to identify cells isolated from the mammary gland of the lactating rat as a prerequisite for cell purification have been developed.

The cells were isolated from mammary tissue with 0. 1% collagenase, and they were visualized by scanning and transmission electron microscopy and by alkaline phosphatase cytochemistry.

The milk-secreting cells have surface microvilli, whereas the surface of the myoepithelial cells is smooth (Fig. 1). The two isolated epithelial cell types are readily distinguishable by transmission electron microscopy (Fig. 2). The secretory cells contain vacuoles and a relatively extensive rough endoplasmic reticulum, whereas the myoepithelial cells contain a more osmiophilic cytoplasm, contractile filaments (Fig. 3) and elongate processes. These features are consistent with the appearance of the two cell types in situ.

Incubation of isolated cells with oxytocin prior to glutaraldehyde fixation resulted in the contraction of the myoepithelial cell processes (Figs. 4 & 5). This physiological response to oxytocin shows that the isolated myoepithelial cells were intact. The appearance of isolated secretory cells was unchanged by the presence of oxytocin.
An electron histochemical study of the invading pattern of the trophoblasts in implanted site of the placental tissue
Authors: Hata Toshio , Ohkawa Kimiyasu
Published: June 2020

Regarding to the biological mechanism of the invading pattern of the trophoblasts into the decidual tissue, it is understood that the analysis is mandatory for the further critical evaluation of the abortion, malformation, sterility and metastatic mechanism of the chorionic tumors. In the literature, importance of the fibrinoid zone which lies between the trophoblasts and decidual tissue(Kirby), cell coat on the trophoblasts(Currie), junctional complexes(Martinek, Ender et al) have placed the emphasis on this aspect. However, the constitutional cells in the implanted site reveal the extrmely variable morphologic figures as they are undergoing various process of proliferation, differentiation and degeneration, therefore, it is required to establish the definite morphologic criteria for differentiation between them. In this view point, the authors have made an investigation for evaluating the ultrastractural feature of each cell in the feto-maternal junctional zone. in this connection, the cytochemical electron microscopic investigation has been applied.
Fine structure of the spermatozoon of Proteocephalus longicollis (Cestoda proteocephalidea)
Authors: Swiderski Z. , Eklu-Natey R. D.
Published: June 2020

The spermatozoon of the proteocephalid cestode Proteocephalus longicollis (Zeder, 1800) is a very elongate, thread-shaped cell, about 300 μ m long and 0, 1 - 0, 9 pm in diameter, with no differentiation into head, midpiece and tail.

The spermatozoon body (Figs. A-K) consists of: (a) two axonemes of the unique “9+1“ pattern, (b) an elongate nucleus, (c) numerous electron-dense, glycogen-like granules of different sizes and shapes and (d) cortical, cytoplasmic microtubules associated with the limiting plasma membrane. The total lack of acrosome and mitochondria is a remarkable and unusual finding which seems to be characteristic for all cestode spermatozoa examined so far.

The nucleus of the spermatozoon, narrow and rod-shaped in its anterior part, becomes progressively enlarged and flattened toward the posterior end. The nuclear envelope is relatively thick and composed of two wavy membranes (Figs. G and H). The nucleoplasm is very loose and consists of fine filaments and granules of chromatin.
Some aspects of the fine structure of goldfish optic tectum
Authors: Roots Betty I.
Published: June 2020

In teleosts the optic tectum is the major integrative centre in the brain. The cyto- and fibre architecture of the optic tectum have been studied extensively and a well-defined laminar pattern has been described. Here some aspects of the fine structure of the optic tectum of the goldfish, Carassius auratus, will be described and discussed. Goldfish which had been kept at a temperature of 15°C were fixed by perfusion with 2. 5% glutaraldehyde in a phosphate buffer. After fixation pieces of the optic tectum from both dorsal and ventral regions, cut so that their original orientation in the tectum could be determined by their shape, were removed. They were post-fixed in 1% osmium tetroxide in the same buffer for 1 1/2 h, dehydrated, stained in 2% uranyl acetate and embedded in epon. Sections were stained with lead citrate.

Lining the ventrical is the ependyma consisting of epithelial-like cells which are 5. 4 μm in diameter, are ciliated, and joined by both desmosomes and tight junctions between their somata.
Effects of temperature on coated vesicle formation within pre-synaptic terminals in cat sympathetic ganglia stimulated in vitro
Authors: Kadota Tomoko , Kadota Ken
Published: June 2020

Many workers have shown the depletion of synaptic vesicles following nerve stimulation but there is a discrepancy among data regarding the appearance of coated vesicles attendant on the decrease in the number of synaptic vesicles (Heuser and Reese, 1973; Ceccarelli et al., 1973; Pysh and Wiley, 1974). The present experiment was an attempt to investigate the effect of temperature on stimulation dependent coated vesicle formation.

Dissected cat superior cervical ganglia were incubated in Krebs solution at 10°C and 37°C respectively. Preganglionic nerves were stimulated with the electrical parameters consisting of 1 msec square pulses of 20 V at 10 Hz for 30 min. After stimulation the ganglia were fixed with 2 % 0s04 (lh). To examine the participation of the coated endocytosis on recovery processes some ganglia were stimulated at 37°C for 30 min and then rested either at 37°C or 10°C for 5 and 15 min before fixation. The fixed material were then processed for electron microscopy with conventional method consisting of uranyl acetate block stain (30 min), dehydration with ethanol series, and embedding in Epon 812.
Ultrastructural localization of neuropeptides in the rat brain
Authors: Van Leeuwen F.W.
Published: June 2020

In order to obtain specific and optimal ultrastructural localization of vasopressin and oxytocin in the hypothalamo-neurohypophyseal system of the rat, 2 staining procedures and several tissue treatments were evaluated using neurohypophyseal tissue. It appeared from these studies that post-embedding staining with the unlabeled antibody enzyme method developed by Sternberger allows greater dilution of the first antibody (anti-vasopressin, 1:4800) than the indirect procedure (1:320) using a peroxidase conjugate as second antibody. Immersion fixation with 4% formalin during 24 hours gave better results (general ultrastructure, immunoreactivity) than those obtained by perfusion fixation with 2.5% glutaraldehyde-1% paraformaldehyde or freeze substitution.

Since no reliable specificity tests were performed at the electron microscopical level, tests were developed for antibodies against both vasopressin and oxytocin. For anti-vasopressin plasma neural lobes of homozygous Brattleboro rats, that are lacking vasopressin by a genet- ical defect, were used. For antibodies against both hormones serial sections were used that were alternately incubated with the antibodies.
Electron microscopic studies of the brain edema after local brain injury in animals with changed immunological reactivity
Authors: Gannushkina I. V. , Sukhorukova L. I.
Published: June 2020

It is well established at present that the course of pathological processes in local brain trauma depends on immunological reactivity of the organism and to a great extent on its sensitization to brain antigens.

This study was undertaken to clarify the early ultrastructural changes of the nervous tissue in perifocal area of local brain wound in normal rabbits, those sensitized to brain antigens or desensitized by brain antigens after preliminary sensitization. In addition, the influence of sensitization and desensitization per se on brain tissue ultrastructure was studied. The animals were sensitized and desensitized with intravenous and intraperitoneal 20% water-salt extract of homologous brain tissue. The immunological state of the animals was checked by using the complement fixation test. The fixation of antibrain antibodies in perifocal area of the wound was studied by the direct Coons immunofluorescence method.
Low sulphur content in atrophied human skeletal muscle: an electron probe X-ray microanalytical study
Authors: Wróblewski R. , Gremski W. , Roomans G. M. , Nordemar R. , Edström L.
Published: June 2020

Many diseases of the human skeletal muscle involve an atrophy of the muscle fibres. In some cases mainly one of the fibre types is affected. The fibre typing system used in this study is that of Padykula and Herman, 1955 and distinguishes between type I fibres which presumably correspond to the slow-twitch fibres and type II fibres which are the fast-twitch fibres. The type II fibres can be divided into type II A, II B and II C fibres. Recent advances in instrumentation and tissue preparation have permitted an investigation of the elemental composition of individual muscle fibres of known fibre type with the aim of comparing healthy and atrophied muscle fibres.

In this study we have examined ten patients suffering from rheumatoid arthritis, two patients suffering from Parkinson's disease and two patients with upper motor lesions. As a control group we have examined muscles from eight healthy controls of the same age.