bluuebunny/crossref_metadata_2025 huggingface dataset:
Butyrylcholinesterase in the Adult Rabbit Heart
Authors: Hagopian M. , Tennyson V.M.
Published: June 2020

The papillary muscle of the adult rabbit heart was studied by a modification of the copper thiocholine technique for the localization of cholinesterase activity. At the ultrastructural level the muscle shows evidence of butyrylcholinesterase (BuChE) in view of the fact that an electron-opaque reaction product, a copper thiocholine complex, forms when butyrylthiocholine (BuThCh) is used as substrate. The deposition of the reaction product was abolished by preincubation with iso-OMPA (tetraisopropyl pyrophosphortetramide) which specifically inhibits BuChE, but not by BW284C51 (1,5-bis [4-allyldimethylammoniumphenyl] penta-3-one dibromide) which inhibits acetylcholinesterase (AChE). When acetylthiocholine (AThCh) was used as substrate, no end product was found.

BuChE activity is seen primarily in the terminal sacs of the sarcoplasmic reticulum (SR) in the region adjacent to the T system (Fig. 1), within the subsarcolemmal vesicles or tubules, and in the endoplasmic reticulum (Fig. 2) of the perinuclear zone. The reaction sites are found occasionally in some areas of the longitudinal elements of the SR, on the nuclear envelope (Fig.2), and in the cisterns which are associated with the intercalated disc. The discs are always negative.
Electron Microscopy of Human Gallstones
Authors: Wolpers C. , Blaschke R.
Published: June 2020

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.

Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.
Ultrastructure of Liver in Lactosyl Ceramidosis
Authors: Hruban Z. , Esterly J. R. , Dawson G. , Stein A. O.
Published: June 2020

Samples of a surgical liver biopsy from a patient with lactosyl ceramidosis were fixed in paraformaldehyde and postfixed in osmium tetroxide. Hepatocytes (Figs. 1, 2) contained 0.4 to 2.1 μ inclusions (LCI) limited by a single membrane containing lucid matrix and short segments of curved, lamellated and circular membranous material (Fig. 3). Numerous LCI in large connective tissue cells were up to 11 μ in diameter (Fig. 2). Heterogeneous dense bodies (“lysosomes”) were few and irregularly distributed. Rough cisternae were dilated and contained smooth vesicles and surface invaginations. Close contact with mitochondria was rare. Stacks were small and rare. Vesicular rough reticulum and glycogen rosettes were abundant. Smooth vesicular reticulum was moderately abundant. Mitochondria were round with few cristae and rare matrical granules. Golgi complex was seen rarely (Fig. 1). Microbodies with marginal plates were usual. Multivesicular bodies were very rare. Neutral lipid was rare. Nucleoli were small and perichromatin granules were large. Small bile canaliculi had few microvilli (Fig. 1).
Timed Sequential Ultrastructural Changes of Canine Kidneys Unflushed and After Flushing with Plasma
Authors: Osborne D. G. , Magnusson M. O. , Kiser W. S. , Hawk W. A.
Published: June 2020

Several methods and solutions have been used to preserve kidneys for transplantation. Among these are Collins C4; Ringer's Lactate and by perfusion by the (Belzer) LI-400 preservation system using plasma. In this experiment we hope to demonstrate ultrastructural changes of kidneys which were flushed with plasma, compared to kidneys which were unflushed.

Eight dogs were used in our experiments. Each dog was anesthesized, the kidneys exposed, biopsied and then removed. Four dogs were sacrificed. One kidney from each dog was flushed with 150 ml of cold plasma, the other was left unflushed. They were then immersed in iced saline and kept at 0° to 4°C for the duration of the experiment. Biopsy times were 0, 1/2, 1, 2, 4, 8, 16 and 24 hours. The kidneys of the four remaining dogs were autografted at various intervals to compare ultrastructural changes with viability. All biopsy specimens were prepared for electron microscopy.
Studies of the Penetration of Bdellovibrio into Host Cells
Authors: Abram Dinah , Chou David
Published: June 2020

The sequence of events in the infectious cycle of the endoparasite Bdello-vibrio bacteriovorus, from its attachment to the host surface to the release of progeny from lysed host are well established. However, the mechanisms involved in the parasite entry through a pore in the host cell wall into its periplasm have been topics for speculations but are not fully understood.

Escherichia coli, Pseudomonas fluorescens and Spirillum serpens were infected by several Bdellovibrio strains (109, D and 6-5-S) in mixtures containing 109 to 1010 host cells/ml and host-parasite in ratios of 1:2 to 1:3, and were incubated at 30 C with shaking for 4 hr. At intervals specimens were prepared for electron microscopy and wet mounts were examined by phase optics.
Metastatic Nodules of Human Breast Cancer Following Prolonged Estrogen Therapy: A Model for Ultrastructural Study
Authors: Swedo John L. , Watson John H. L. , Talley R. W.
Published: June 2020

Most of the models in the studies of breast cancer use murine tissues. Data from these studies, based on the “milk factor” theory, promoted the discovery of the mammary tumor virus (MTV). Electron microscopy of murine tissues, both in vivo and in vitro, and fractions of milk from tumor bearing mice confirmed and described the MTV entity at the ultrastructural level. Application of information obtained from studies of the murine model to the human problem has been difficult in the past for technological reasons, or more importantly, a lack of consistent or controlled sources of human materials. With technological improvements, studies of human material of a more controlled nature, based on population statistics, have been accomplished. The source of tissues studied in this presentation are recurring metastatic nodules from patients who had been treated for breast cancer. Easily accessible nodules from both estrogen treated and untreated patients were compared in this study. No differences were found. Recent reports of virus particles or virus-like particles, particularly of the B type variety, have promoted the search for them in human tissues.
Morphogenesis of an Arbovirus as Seen by Freeze-Etching
Authors: Brown Dennis T. , Waite Marilynn R. , Pfefferkorn Elmer R.
Published: June 2020

The freeze-etch technique, as introduced by Steer and modified by Moor provides a method for examining cell systems under conditions which minimize ultrastructural alterations during processing. This technique is particularly valuable for morphological studies of membranes and membrane associated structures as fracture lines tend to preferentially expose such surfaces. These factors indicate that the freeze etch technique might be of value in studying the morphogenesis of a cell membrane associated virus. The Group A arbovirus Sindbis is an enveloped virion the maturation of which is dependent upon a specific interaction with host cell membranes. The envelope of the Group A arboviruses have been shown by negative staining to consist of spike or fiber like structures of about 110Å length. This fibrous envelope is obtained as the viral nucleocapsid buds through plasma on vacuolar membranes. It has been suggested that the cell membrane is specifically modified at the point of viral exit to provide the “spiked” morphology of the envelope.
An Investigation of the Pyroantimonate Reaction for Sodium Localisation Using the Analytical Electron Microscope, EMMA-4
Authors: Herman L. , Sato T. , Weavers B. A.
Published: June 2020

The analytical electron microscope, EMMA-4, is designed specifically to perform x-ray microanalysis of conventional transmission electron microscope specimens.

The analysis facilities consist of two fully focussing crystal spectrometers each of which can be tuned to collect x-rays emitted from elements of atomic number greater than 11. In addition to the two crystal spectrometers there is a non-dispersive detector which can be used to monitor the total x-ray emission of the specimen and adds the facility for determination of the “continuum” radiation for quantitative analysis. The exact area of analysis is always located by direct observation of the viewing screen.
Glass Knife Geometry as Seen by the SEM
Authors: Black J. Temple
Published: June 2020

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.
The Ultrastructure of Secretory Cells in Endometrial Cups of Pregnant Mares
Authors: González-Angulo A. , Hernández-Jáuregui P.
Published: June 2020

Male and female differentiated fetal gonads of Equus caballus at the age of three to ten months of gestation are made up for the most part by large numbers of interstitial cells. This is in keeping with the well known fact that fetal gonads are increased in size during the above mentioned period of gestation. The gonads decrease in volume to attain a much smaller size shortly before birth. Although pregnant mare serum gonadotrophins (P.M.S.G.) determinations yielded negative results in fetal sera, the fine structure of interstitial cells is that of a hormone stimulated cell as seen in the experimental animal. At present the site of production and the way the P.M.S.G. reaches both the fetus and the mare serum is unknown. The purpose of the present paper is to postulate on morphological grounds that specialized endometrial cells present in the cups of pregnant uterus may be the site of P.M.S.G. production.
Smooth Muscular Cells in the Mammalian Ovary
Authors: Fumagalli Z. , Motta P. , Calvieri S.
Published: June 2020

The presence of smooth muscular cells was demonstrated with the electron microscope in different areas of the ovary of cats, mice and rabbits. The myocytes were arranged in fascicles, small groups, or most frequently appeared isolated. They were scattered in the ovarian stroma, related to the interstitial cells, in the periphery of the corpora lutea (rarely between luteal cells) in the middle of the gland. Smooth muscular cells were seldom observed between cells of the theca interna and externa of developing follicles and in the middle of atresic follicles. Some smooth muscular cells were found in the cortical area of the ovaries.

Each smooth muscular cell showed typical filaments, free ribosomes, lipid droplets and at times glycogen particles. Mitochondria were vesicular; the (Golgi) vesicular complex was often related to two centrioles (frequently in a process of ciliogenesis). The granular endoplasmic reticulum was moderately developed. The plasma membrane presented invaginations and micropinocytotic vesicles as well as tight junctions between adjacent cells. The nucleus was elongated and its envelope formed wide perinuclear cisternae.
Osmotic Shock, A New Technique to Spread Eukaryotic Nuclear Chromatin
Authors: Abdel-Hameed Fathi
Published: June 2020

While Langmuir trough has been used successfully by many investigators for spreading nuclear contents into monolayer films, certain cell types do not spread readily. For example, chicken nucleated erythrocytes and human sperm heads do not spread in the Langmuir trough (Fig. 1) while those of amphibian erythrocytes and grasshopper sperms spread well. Apparently the former possess a rather rigid membrane system. Removing the membranes of human or bull sperm heads by alkaline thioglycolate exposes their nuclei and gives adequate chromatin spreading.

In these cell types, the application of osmotic shock technique eliminates the necessity for removing cytoplasmic membranes by chemical digestions. Disruption of both cytoplasmic and nuclear membranes is achieved by employing adequate differences in osmotic pressures between the hypo- and hyperphase solutions. Less than 0.1 ml of embryonic or adult chicken venous blood is mixed with equal volume of chilled isotonic anticoagulant solution (20 g. sodium citrate + 4.2 g. sodium chloride in a liter of distilled water). The erythrocytes are suspended to a final concentration of about l05/ml in a hyperphase solution of 1.0 ammonium acetate, 0.5% neutralized formaldehyde and 0.1% cytochrome C. A volume of 0.01 ml of well mixed chilled hyperphase is poured down an inclined wet glass slide into a petri dish containing chilled hypophase solution of 0.1 M ammonium acetate and 0.5% neutralized formaldehyde.
Positive Staining of (Pectin) Carboxyl Groups for Electron Microscopy
Authors: Leeper George F.
Published: June 2020

The demonstration of pectic acid elementary fibrils by negative staining has prompted an attempt to demonstrate such structures by positive staining. Positive staining of specific reactive groups could give insight into elementary fibril organization as well as cell wall morphology.

Because pectin staining based on esterified groups is insensitive to pectic acid, and pectin esterification is rarely total, attempts were made to stain free carboxyl groups. The formation of heavy metal salts or unsaturated esters with subsequent osmification are two methods for imparting electron density to carboxyl groups.

The labile nature of pectin in water is probably responsible for amorphous configurations observed after formation of heavy metal pectates in aqueous systems. Morphology can be maintained by rapid dehydration of pectin solutions in organic solvents followed by salt formation using silver acetate dissolved in the organic solvent. Attempts to form uranyl pectates under these conditions resulted in large amorphous regions presumably because of molecular cross-linking by the divalent uranyl ion.
Organized Intraglomerular Deposits in NZB Mouse Disease
Authors: Comerford Francis R. , Cohen Alan S.
Published: June 2020

Mice of the inbred NZB strain develop a spontaneous disease characterized by autoimmune hemolytic anemia, positive lupus erythematosus cell tests and antinuclear antibodies and nephritis. This disease is analogous to human systemic lupus erythematosus. In ultrastructural studies of the glomerular lesion in NZB mice, intraglomerular dense deposits in mesangial, subepithelial and subendothelial locations were described. In common with the findings in many examples of human and experimental nephritis, including many cases of human lupus nephritis, these deposits were amorphous or slightly granular in appearance with no definable substructure.

We have recently observed structured deposits in the glomeruli of NZB mice. They were uncommon and were found in older animals with severe glomerular lesions by morphologic criteria. They were seen most commonly as extracellular elements in subendothelial and mesangial regions. The deposits ranged up to 3 microns in greatest dimension and were often adjacent to deposits of lipid-like round particles of 30 to 250 millimicrons in diameter and with amorphous dense deposits.
Merkel Tactile Cells of the Human Embryo Nail
Authors: Hashimoto K.
Published: June 2020

The Merkel tactile cell of the human skin has mainly been described in association with the Haarscheibe (hair disc) in the part of the body where lanugo hairs are present. In the present survey a number of Merkel cells were found in the nail matrix of 15-18 weeks old human embryos (figs. 1,2). Dorsal matrix contained more cells than the ventral half. It was also found in the perivascular spaces of the finger of the same embryos (fig. 3). In both locations nerve endings rich in mitochondria and synaptic vesicles were in direct contact with the Merkel cell (figs. 1-3). In the nail matrix the Merkel cell was most commonly found within or just above the basal layer. Less frequently, they were present in the upper dermis. Such dermal Merkel cells were completely covered with basal lamina suggesting that they were projecting downward from the basal layer. Occasionally, two cells with centrioles were seen side by side suggesting that one of them was produced from the other by mitosis (fig. 1).
High Oxygen Pressures as a Contributing Factor in Retinal Detachments
Authors: Philpott Delbert E.
Published: June 2020

Retinal detachment results from a number of causes and has received attention since 1904 when Gonin postulated the entry of vitreous fluid into the pigment area after a hole occurred in the retina. A symposium on retinal detachment held in 1952 summarized the current information and concluded that breaks in the retina are the most essential factor in the production of detachments and listed three main causes for such breaks: l) localized atrophying processes; 2) localized vitreous pull and 3) trauma. Recent work in our laboratory with tissue culture cells and animals exposed to 100% oxygen has suggested another mechanism.

Mouse fibroblast L-929 and Don Chinese Hamster tissue culture cells were exposed for 3, 6 and 12 hours to 100% oxygen at one atmosphere while the rats and rabbits were exposed to the same conditions for 12, 24, 36, 48 and 72 hours. The tissue culture cells were fixed in situ to reduce any mechanical damage and the animals were fixed by perfusion to prevent any movement of the retina before fixation. Conventional methods of dehydration, embedding and sectioning were used.
Mitochondrial Changes in the Adrenal Glands Following the Administration of 7,12-Dimethylbenzanthracene
Authors: Murad T. M. , Leibach J. R. , von Haam E.
Published: June 2020

Adrenal cortical necrosis and apoplexy have been described by Huggins and Morii to follow single or multiple intravenous injections of 7,12-dimethyl-benzanthracene into female Sprague-Dawley rats. This phenomenon is species- and strain-specific and occurs within a few days after DMBA administration. The mechanism by which the chemical exerts its damaging effect on the adrenals is not known although it has been suggested that the 7-hydroxymethyl derivative produced in the liver is the responsible agent. The adrenal cortical necrosis is dose-related and can be prevented by pre-treatment of the animals with 3-methylcholanthrene or Sudan III.

In the present study the adrenal glands from 31 animals which had developed breast tumors after treatment with 7,12-DMBA were studied by light and electron microscopy. Five animals were injected with DMBA and five weeks later were injected with tritiated thymidine three hours before sacrifice. The adrenals from these animals were studied by autoradiography.
High-Voltage Scanning Electron Microscopy
Authors: Cowley J. M.
Published: June 2020

The comparison of scanning transmission electron microscopy (STEM) with conventional transmission electron microscopy (CTEM) can best be made by means of the Reciprocity Theorem of wave optics. In Fig. 1 the intensity measured at a point A’ in the CTEM image due to emission from a point B’ in the electron source is equated to the intensity at a point of the detector, B, due to emission from a point A In the source In the STEM. On this basis it can be demonstrated that contrast effects In the two types of instrument will be similar. The reciprocity relationship can be carried further to include the Instrument design and experimental procedures required to obtain particular types of information. For any. mode of operation providing particular information with one type of microscope, the analagous type of operation giving the same information can be postulated for the other type of microscope. Then the choice between the two types of instrument depends on the practical convenience for obtaining the required Information.
Fundamental Limitations on Electron Molecular Microscopy
Authors: Trammell George T. , Breedlove James R.
Published: June 2020

We consider the feasibility of an electron “molecular microscope” which could be used to determine the structure of a biological molecule by forming an image in which its individual atoms are resolved.

Each atom which is imaged must scatter at least one electron. (This is true irrespective of the imaging technique so long as the images of neighboring atoms are resolved.) While we may ignore the effects of the elastically scattered electrons on the molecular structure, inelastic collisions will lead (with a certain probability) to molecular dissociation or rearrangement. The “image” formed will thus be a composite picture of the molecule over the history of its irradiation and may bear little relation to the original molecular structure, and this is a fundamental “Limitation on molecular microscopy.
Morphology of Apollo 11 and 12 Soil Samples and the Quest for Biogenic Forms
Authors: Philpott Delbert E. , Turnbill Charles
Published: June 2020

The Apollo 11 and 12 missions to the moon returned valuable samples for scientific study. The morphology of the loose sediment and breccia from Apollo 11 have been studied extensively in our laboratory using light microscopy, electron microscopy, scanning electron microscopy and the electron probe. The Apollo 12 sample is now undergoing similar treatment.

Even though conditions on the moon, especially on the surface, are known to be extremely hostile to life as we know it, an extensive search was carried out for evidence of past life. Since numerous reports exist purporting evidence of life forms in carbonaceous chondrites coming to the Earth from outer space, such material would also be expected to be embedded in the lunar surface. Enders calculates about 2% carbonaceous chondrites on the lunar surface and Keil had measured nickel iron meteoritic ratios in his sample as about 1%. Thus influx to the surface and undetermined past history add interest to the search. However, an estimated turnover rate of 120 million years for a few inches of lunar soil does mean long exposure of this material to radiation, severe temperature changes, high vacuum, etc.
Ultrastructure of Eosinophilic Leucocyte Granules of Dog Blood
Authors: Hung Kuen-Shan , Scott Earl B.
Published: June 2020

The presence of crystalloid material in the core of granules was a common characteristic of eosinophilic leucocytes of the cat, mouse, rat, guinea pig, and human. This crystalloid interior was not seen in eosinophil granules of the horse. Another electron microscopic study of leucocytes of canine blood concluded that dog eosinophil granules lacked this crystalloid and, were different from that of other species. We found crystalloid material present in granules of blood eosinophils of a group of five adult dogs.

Approximately 10 ml of blood was withdrawn in a heparinized syringe. The blood was centrifuged at 4000 rpm for 15 minutes. The buffy coat was fixed in cold 0.1M phosphate buffered 2.5% glutaraldehyde for 10 minutes, minced and fixed in same glutaraldehyde for an additional hour, and post-fixed in cold 1.33% osmic acid in s-collidine buffer for 2 hours.
The Influence of Ammonium Molybdate, Silicotungstic Acid and Phosphotungstic Acid on Function and Structure of Mitochondria
Authors: Mergner W. J. , Pendergrass R. , Trump B. F.
Published: June 2020

A negative stain should produce no structural change in the specimen. Our results indicate that this is not the case with at least two negative stains. There is a spectrum of changes which depends on the stain used. The negative stain also causes functional alterations which involve three basic functional characteristics of the mitochondria: 1) oxidative phosphorylation, 2) electron transport and 3) ion permeability. Rat kidney mitochondria were resuspended in the negative stain for 15 minutes (except for kinetic studies). For electron microscopy they were: 1) directly applied to grids; 2) fixed with glutaraldehyde and OSO4 and embedded in Epon; and 3) prepared by freeze fracturing. Mitochondria stained with ammonium molybdate (AM) revealed two types of profiles. They had either a dense inner compartment without penetration of negative stain displaying the commonly observed image (Fig. 3 and 4). With penetration the inner membrane was studded with spheres, but the spheres were not on discernible stalks (Fig. #5).
Fine Structural Alterations in the Cardiac Myofibres of Senescent Houseflies
Authors: Sohal R. S. , Allison Venita F.
Published: June 2020

Cytologic changes in the terminal phase of the life of cardiac myofibres in the vertebrates are little understood due to the difficulty in distinguishing between the changes arising primarily from aging and those brought on secondarily by the blood vessel changes. Some invertebrates such as insects are devoid of a vasculature as the oxygen is carried directly to the tissues by a network of tracheal tubes. Consequently, temporal alterations in the structure of the insect heart can be considered to be age-related. There is physiological evidence that insect heart undergoes regressive functional changes with age. The present report is concerned with the fine structural alterations in the heart of the housefly, Musca domestica, with age.
Ultrastructure of the Intestinal Absorptive Cells of Fed and Fasted Tadpoles
Authors: Giaquinta Robert , Hayat M. A.
Published: June 2020

The ultrastructural changes that occur in the intestinal absorptive cells during amphibian metamorphosis have been reported (Bonneville, 1963). These changes accompany a change in diet (from an herbivorous to a carnivorous state) during metamorphosis. Little information is available, however, on the ultrastructural changes in the absorptive cells of amphibians in relation to the state of feeding. This report describes the differences in the fine structure of these cells in the tadpole stage of Rana pipiens during periods of food absorption and fasting.

Rana pipiens at tadpole stages were fed an herbivorous diet, and after a period of 48 hr, the animal was dissected and segments of the small intestine were collected for electron microscopy. A second group of tadpoles was fasted for 7 days, and segments of the small intestine were collected. The tissue specimens were immersed in phosphate-buffered glutaraldehyde (3%) for 1 hr at 4C and postfixed with phosphate-buffered osmium tetroxide (2%) for 1 hr at 4C.
Organization of the Pellicle and the Muciferous Glands in Euglena Gracilis
Authors: Mollenhauer Hilton H. , Evans W.
Published: June 2020

The pellicular structure of Euglena gracilis consists of a series of relatively rigid strips (Fig. 1) composed of ridges and grooves which are helically oriented along the cell and which fuse together into a common junction at either end of the cell. The strips are predominantly protein and consist in part of a series of fibers about 50 Å in diameter spaced about 85 Å apart and with a secondary periodicity of about 450 Å. Microtubules are also present below each strip (Fig. 1) and are often considered as part of the pellicular complex. In addition, there may be another fibrous component near the base of the pellicle which has not yet been very well defined.

The pellicular complex lies underneath the plasma membrane and entirely within the cell (Fig. 1). Each strip of the complex forms an overlapping junction with the adjacent strip along one side of each groove (Fig. 1), in such a way that a certain amount of sideways movement is possible between one strip and the next.
Some Morphologic Features of Axial Fibers and Body Fibrils of Treponemata
Authors: Jones Ronald H. , Yoshii Zensaku , Carver Oscar J.
Published: June 2020

Four strains (Reiter, Kazan 2,4,5) of treponemata were cultivated at 37° C for 3-7 days in standard media containing complement inactivated rabbit serum (Cannefax, Spirolate) and in a defined medium devised by Johnson and his associates (unpublished data). Electron microscope preparations included cells which were unwashed (harvested), washed up to seven times, autolysed, or ruptured by explosive decompression. Each preparation was fixed with gluteraldehyde or left unfixed. Negative staining was performed using phosphotungstic acid (PTA - pH 7.2) or ammonium molybdate (AM - pH 7.0-7.2). Electron microscopy was done with a JEM 6A model at 80kV using a magnification range of 10,000-50,000X.

The autolytic and disruption techniques were most effective for visualizing the ultrastructure of the more internal cell layers or moieties. The number of axial fibers (AF) arising from each cell pole varied from 4-7, six being the most common.
The Microenvironment of Neurons
Authors: Bondareff William
Published: June 2020

Neurons in the central nervous system are separated by extracellular spaces, the distribution, composition and function of which are not unequivocally known. Earlier electron microscopic studies of chemically-fixed tissues demonstrated extracellular spaces composed of uniformly narrow, apparently empty channels constituting 3-5% of the brain volume. The results of more recent morphological and non-morphological studies support the existence of less uniform intercellular channels, varying in dimension from 100 Å to almost 1 μ, and constituting 20-25% of the brain volume. Although this space is not revealed in electron micrographs of chemicallyfixed nervous tissues, it is demonstrated readily in specimens fixed by freeze-drying or freeze-substitution (Fig. 1). The dynamic nature of those extracellular spaces, as visualized in electron micrographs of nervous tissue fixed by freeze-substitution, was demonstrated in studies of normalbrain maturation. An extracellular space of 40% became gradually smaller as development proceeded to reach the smaller extracellular space characteristic of mature animals.
Neural Organization of Peripheral Sensory Receptors of Cephalopod Molluscs
Authors: Graziadei P. P. C.
Published: June 2020

If one observes the behavior of an octopus and of a squid, one may notice marked differences in the manipulation of objects by the arms and suckers in these two animals. In the case of the octopus a number of complex manipulations are performed by both the arms and the individual suckers. The squid appears to utilize its arms and suckers only for the purpose of grasping and drawing potential food to the mouth. It is conceivable that this difference in behavior is due to disimilar distribution and organization of sensory receptors in octopods and decapods. Octopods may obtain chemical and mechanical information at the level of the suckers while decapods appear to obtain this information at the level of the mouth.
Localization of Intracellular Antigens in thin Sections with Ferritin Labeled Antibody
Authors: Shahrabadi M.S. , Yamamoto T.
Published: June 2020

The technique of labeling of macromolecules with ferritin conjugated antibody has been successfully used for extracellular antigen by means of staining the specimen with conjugate prior to fixation and embedding. However, the ideal method to determine the location of intracellular antigen would be to do the antigen-antibody reaction in thin sections. This technique contains inherent problems such as the destruction of antigenic determinants during fixation or embedding and the non-specific attachment of conjugate to the embedding media. Certain embedding media such as polyampholytes (2) or cross-linked bovine serum albumin (3) have been introduced to overcome some of these problems.
Timed Sequential Ultrastructural Changes of Kidney After Perfusion with Collins C-4 And Ringer'S Lactate - A Preliminary Study
Authors: Osbarne D. G. , Magnussen M. , Kiser W. S . , Hawk W. A.
Published: June 2020

One of the primary difficulties of kidney transplantation is keeping the kidney viable until a recipient is prepared to receive it. G. M. Collins, F.R.C.S. from the University of California recently announced a perfusate which would keep a kidney viable for up to thirty hours.1 The purpose of this study is to compare ultrastructural differences between the effects of Collins C-4 perfusate and Ringer's lactate.
Choroid Plexus Papillomas: an Ultrastructural Study
Authors: Beggs John L. , Waggener John D. , Carter Philip L.
Published: June 2020

Choroid plexus papillomas make up about 0. 5 per cent of brain tumors and are of particular interest in that they are frequently associated with obstructive and communicating hydrocephalus.

Histologically, normal choroid plexus consists of many villi composed of cores of highly vascular connective tissue with an overlying single layer of cuboidal or low columnar epithelium. Ultrastructural studies (Beggs, Thesis, 1969, Arizona State University) of normal choroid plexus epithelium show the microvilli at the apical surface to be irregular in shape and size. In addition to microvilli at the apical surface, occasional cilia are present. The basal region is characterized by having numerous infoldings and large intercellular spaces.
Comparison of Goldthioglucose and Monosodium Glutamateinduced Lesions In the Hypothalamus of Mice
Authors: Arees Edward A. , Mayer Jean
Published: June 2020

The compound goldthioglucose (GTG) has been shown to produce lesions in the ventromedial region of hypothalamus in mice. Also, lesions in the same region of hypothalamus have been reported after single parenteral administration of monosodium glutamate (MSG). This study has examined the development of these lesions over time with the electron microscope.

Mice were given single intraperitoneal injections of either GTG (either 0.2 or 0.6 mg/g body wt) or MSG (either 4.0 or 6.0 mg/g body wt). Animals injected with GTG were killed at times varying between 1 hr - 14 days post injection while those injected with MSG were killed between 3 hours and 3 days after injection. Hypothalamic lesions that developed 3 hours after MSG injection involved only glia cells (Fig. 1) immediately lateral to the base of the third ventricle in the accuate nucleus.
Diagnostic Use of Electron Microscopy in Female Disease
Authors: Roberts D. K. , Wharton J. T.
Published: June 2020

The use of the electron microscope as a diagnostic as well as research tool in the study of female genital disease appears promising. Electron microscopic evaluation of renal biopsy specimens are of considerable assistance in the differential diagnosis of certain nephropathies associated with the hypertensive pregnant female. The ultra structural study of endometrium in sterility problems gives considerably more information regarding the cycle-related response of this target organ than does light microscopic study. The absence of intranuclear inclusions during the early to mid-luteal phase in these otherwise physiologically normal females may be of considerable future diagnostic importance as well as giving insight into the basic problem.
Ultrastructural Changes During Development of Myocardial Hypertrophy
Authors: P. Bishop Sanford
Published: June 2020

Although it has been shown that the myocardial cell may increase in both width and length with hypertrophy, there is little morphologic evidence for the mechanism of this increase in cell size or for the decreased contractility associated with hypertrophied and failing myocardium. It has been suggested that the myocardial cell may increase in size by one or more of three means: 1) an increase in the number of myofibrils, 2) the addition of normal sized filaments to the periphery of already existing myofibrils, or 3) by the addition of new complete sarcomere units to the cell.
Electron Microscopic Study of Liver and Spleen From a Human Hemophiliac
Authors: Liss R. H. , Norman J. C.
Published: June 2020

Hemophiliacs bleed because they lack antihemophilic factor VIII (AHF). If an available, transplantable source of AHF could be identified, some mediation of the deficiency in hemophiliacs might be possible.

Reports in the literature indicate spleen and liver to be the principal sites of AHF formation (1). The abundant reticuloendothelial elements in these organs have been suggested as possible sites of AHF activity (2). However, definitive data on the tissue and cellular loci of AHF are lacking.
Ultrastructural Investigation of Chronic Interstitial Pneumonitis in a Tungsten Carbide Worker
Authors: H.L. Watson John , L. Swedo John , Osborne Coates E.
Published: June 2020

Prolonged inhalation of tungsten carbide has long been suspected of causing progressive lung disease in humans. In the work reported, tungsten carbide (WC) has been identified by X-ray diffraction in lung tissue from a tungsten carbide worker. While the major part of the raw material handled by the patient is known to have been tungsten carbide, it also contained 6% cobalt, with trace amounts of other metals. Neutron activation analysis with the same tissue has confirmed the presence of large amounts of tungsten, and the faint lines of tungsten were also revealed by optical emission spectroscopy. Light microscopy has showed extensive, patchy, interstitial pneumonitls with considerable cellular component, interstitial fibrous tissue and metaplasia of the alveolar epithelium. For electron microscopy the tissue was fixed in caccodylate buffered glutaraldehyde, post-fixed in phosphate buffered osmium tetroxide, embedded in Araldite and thin sectioned with a diamond knife. The sections were further contrasted with lead citrate and uranyl acetate.
The Structure of Chromatin
Authors: Jones Janice L. , Beer Michael
Published: June 2020

Chromatin from calf thymus has been reinvestigated.

If the extraction procedure of Zubay and Doty is altered through the omission of EDTA and the resulting fibrils are picked up on grids by the method of Koller et al from a solution containing no added salt, one observes fibrils of diameter about 230 Å. (Figure A). This is the same diameter as was found by DuPraw and Bahr for the component fibrils of isolated honey-bee chromosome's. If the salt concentration is increased, strands of diameter approximately 100 Å are found. The transition from 230 Å to 100 Å fibrils occurs not as a separation into two fibrils but as a thinning and elongation.
Whole Mount Electron Microscopy of Chicken Microchromosomes
Authors: A. Okada Tadashi , E. Comings David
Published: June 2020

Although many observations have been made on the ultrastructure of chromosomes by whole mount electron microscopy, the large size of most chromosomes has made it difficult to trace the chromatin fibers throughout the entire course of a given chromatid.

In the present study, microchromosomes of the chicken were used to provide information on this facet of chromosome structure. Cells from a tissue culture of chicken embryo fibroblasts were exposed to colcemid 0.1 ug/ml for 3 hours and the cells in mitosis were selectively removed by shaking with 0.05% trypsin.
Regional Differences in the Morphology of Motile Cilia Seen by Scanning Electron Microscopy
Authors: A. Luse Sarah , W. Dempsey Edward , J. Agate Frederic
Published: June 2020

The basic structure of motile cilia is remarkably similar in different species and in various specialized epithelia. Few variants in the morphology of cilia have been recognized. Exceedingly long cilia have been termed flagella and considered as a separate type. In the retina, rods and cones are modified ciliary structures. The saccus vasculosus, a diverticulum of the cerebral third ventricle of fishes, contains crown or coronet cells, so called because of the bulbous tips of the short club shaped cilia. Figure 1 is a transmission electron micrograph of the saccus vasculosus and Figure 2 is a scanning electron micrograph of the crown cells viewed from above. Kinetocilia elsewhere have been thought to have almost identical morphology except for variations in the apical or basal terminations of the peripheral intraciliary fibers.
Application of Scanning Electron Microscopy to Myxomycete Taxonomy
Authors: A. Murphy Judith
Published: June 2020

Taxonomy of the Myxomyoetes has been based primarily on morphological characteristics observed in the light microscope. Although the fruiting stage is sensitive to environmental conditions, most species exhibit a distinctive although variable category, and thus characteristics of this stage have been used for morphological differentiation. There has been and still is, however, much disagreement concerning the classification and relationships between members of this group. Although capillitial and spore morphology are used in taxonomic classifications, because of their small dimensions they are often poorly defined or not visible in the light microscope. These characteristics are easily discernible by surface scanning electron microscopy (SEM). The purpose of this initial study was to investigate appropriate sample preparations and determine if taxonomically valuable information could be provided with the use of SEM.
Pipes Buffer: Effect Of Osmolality On Morphology Of Squash R00t Tips
Authors: Martin Albert R. , Bystrom Barbara G.
Published: June 2020

Buffers routinely used in electron microscope work are often unsuitable for non-routine work. We have found that piperazi ne-N,N bis(ethane sulfonic acid), monosodium salt, (PIPES) is a suitable buffer for both routine and non-routine work. PIPES is one of a class of buffers specifically designed for biological use by Good et al(1), and has many useful properties.

From the work of Schultz and Karlsson (2), we knew that buffer osmolality was an important parameter in preserving tissue morphology. Thus before we could use PIPES as a buffer for electron microscope work, a study on the effect of PIPES osmolality on morphology was needed. The results of this study are summarized below.
Development of Homologous Organelles in Insect and Mammalian Sperm
Authors: M. Phillips David
Published: June 2020

Though examination of insect and mammalian sperm reveals many apparently significant differences in ultrastructure, analysis of the development of sperm suggests that most of the differences may be superficial. Indeed, the degree of homology in development of sperm of two such widely divergent classes is impressive. For instance, acrosomes of both insect and mammalian sperm form in similar relationships to the Golgi, and the final form of the acro¬somes of many mammalian species is not much more different from the form of the acrosomes of many insect species than from acrosomes seen in other types of mammalian sparm. The process of nuclear condensation in mammals proceeds in a very similar fashion to the process in insects, generally involving a ring of microtubules (the manchette). In both classes the flagellum originates from a centriole which disappears later during spermiogenesis.
Cytochemical and Morphological Differentiation of Epithelial Cells in Ductuli Efferentes of Chinese Hamster.
Authors: Yokoyama Masao , P. Chang Jeffrey
Published: June 2020

Light microscopy and histochemistry of ductuli efferentes have been frequent subjects of investigation among various species of animals. Only a limited number of ultrastructural studies on this organ have been published. Adequate data on the fine structure and ultracytochemistry of ductuli efferentes of Chinese hamster are not available in the literature. Investigation of this subject therefore was initiated in this laboratory. Some preliminary findings are reported herein.

Two distinctive types of cells, namely ciliated and nonciliated, are observed in the epithelia. The ciliated cells ('Fig. 1) always have typical kineto-cilia with 9 + 2 groups of microtubules. A few microvilli may be intermingled with the cilia on the apical surface of the plasma membrane. Also in the apical region, a peculiar structure (Fig. 1, arrow) resembling the “fibrogranular material” of respiratory epithelium is present. Its presence in the ductuli efferentes has not been reported previously.
Cilia in Endometrial Stromal Cells of the Hamster Uterus
Authors: Clark M. V. , Brinsfield T. H.
Published: June 2020

During an investigation on the ultrastructure of the hamster uterus cilia-like structures were frequently observed in the cells of endometrial stroma. The occurrence of these structures stimulated further investigation to determine if their morphological characteristics were similar to typical cilia.

Specimens of uterine endometrium from hamsters in estrus or during various stages of pseudopregnancy were fixed for 1 hour at 4° C in Millonig's 1% buffered osmium tetroxide at pH 7.4, dehydrated, and embedded in an Araldite-Epon mixture and cured for 48 hours at 60° C. Sections for electron microscopy were cut with a MT-1 Porter-Blum Ultra-Microtome and stained with a saturated solution of methanolic uranyl acetate and viewed in a Philips EM 200 electron microscope.
Thermal Considerations in Lens Regulator Systems
Authors: Newton K.C.
Published: June 2020

Thermal effects in lens regulator systems have become a major problem with the extension of electron microscope resolution capabilities below 5 Angstrom units. Larger columns with immersion lenses and increased accelerating potentials have made solutions more difficult by increasing the power being handled. Environmental control, component choice, and wiring design provide answers, however. Figure 1 indicates with broken lines where thermal problems develop in regulator systems

Extensive environmental control is required in the sampling and reference networks. In each case, stability better than I ppm/min. is required. Components with thermal coefficients satisfactory for these applications without environmental control are either not available or priced prohibitively.
Gas Bearing Support For High Performance Electron Optical Columns
Authors: McGinnis James J.
Published: June 2020

An ultimate and sometimes insurmountable barrier to attaining high resolution micrographs with a high-performance electron optical column is relative motion among column elements during the exposure time of a plate. Such motions may be excited from within the column as, for example, stage drift due to beam heating. Most often however, these resolution-limiting movements are excited and powered from external sources such as pumps, compressors, generators, elevators, traffic, etc.. A significant problem for the instrument designer therefore, is how can inevitable mechanical motion in the environment be kept from propagating into the column. One powerful solution to this problem is to support the column on a gas bearing.