bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microanatomy of the Periplasm of Bacillus Licheniformis
Authors: Ghosh B.K. 
Published: June 2020

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.
Intracytoplasmic Membrane Formation in the Hydrocarbon Oxidizing Bacterium, Micrococcus Cerificans
Authors: Kennedy R. S. , Spurlock Ben O. , Finnerty W. R. 
Published: June 2020

Micrococcus cerificans is a gram negative, pleomorphic, coccoid bacterium capable of growth in complex or chemically defined media. The complex medium employed was nutrient broth-yeast extract (NBYE) while hydrocarbons constituted the sole source of carbon and energy in the chemically defined medium. Cells cultured in the above media were harvested in the late logarithmic growth phase and fixed according to the procedure of Kellenberger, et al. A variety of embedding techniques were used including those developed by Luft; Staubli; and Spurlock et al.M cerificans cultured in the NBYE medium showed characteristic gram negative morphology including mesosomes. In the hydrocarbon grown cells an intracellular membrane system distinct from mesosomes was observed. Evidence suggests that these highly ordered membranous structures which appear as sheaths or bundles extending the width and/or length of the cells are continuous with the cytoplasmic membrane and are specific to hydrocarbon grown cells.
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.
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.
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.
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.
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.
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.
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.
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.
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.