Biology Commons^™

Scanning Electron Microscopy Of Cyclosporine-Induced Gingival Overgrowth, Shahid H. Ashrafi, Krzysztof Slaski, Kyaw Thu, Eli S. Neiman, Michael P. Cunningham

Scanning Microscopy

Overgrown human gingival specimens were examined histologically and by scanning electron microscopy (SEM) to study structural changes caused by cyclosporine. The biopsy specimens were from organ transplant recipients receiving cyclosporine to suppress the rejection of the transplanted organ. The epithelium of the overgrown gingiva was thickened, acanthotic and parakeratotic. Retepegs were anastomosing and extending into connective tissue. The SEM examination of the outer surface of the attached gingival showed loss of cellular attachments and cells were exfoliating. The normal honeycomb structure formed by interconnecting microvilli surrounding the pits was distorted. Outer gingival cell surface showed numerous round, ovoid and dome-like …

Examination Of Injected Specimens By Confocal Laser Scanning Microscopy And Scanning Electron Microscopy, A. Castenholz

Scanning Microscopy

Although corrosion casts commonly examined by scanning electron microscopy (SEM) offer good insights into the general arrangement of the microvasculature of certain organs, no information can be obtained from such specimens on special morphological data or dynamic events. Thus, most investigators are obliged to make their interpretations of cast structures only on the basis of indirect criteria. A synopsis, which considers the most important data in that respect, is given for the blood and lymphatic microvessels. Moreover, a methodological approach is introduced, based on the application of fluorescent resin, which allows the examination of cast structures in uncorroded specimens together …

Vascular Architecture Of The Lactating And Non-Lactating Teat Of The Bitch: A Scanning Electron- And Light Microscope Study, F. J. Pérez-Aparicio, V. Dantzer, M. Navarro, A. Carretero, J. Ruberte

Scanning Microscopy

Tissues from fourteen mammary glands of eight bitches were prepared for scanning electron microscopy of vascular corrosion casts and for histology to study the vasculature of the lactating and non-lactating teats. The densely-meshed mammary dermal capillary network formed ridges and troughs. The teat ducts were vascularized by a relatively densely-meshed capillary network which drained into veins longitudinally oriented to the ducts. Between eight and fifteen teat duct openings were seen on the tip of the teat, that were sometimes divided by a septum. The inner vascularization of the teat showed that the main papillary arteries divided into undulating secondary papillary …

Contribution Of Conventional And High Resolution Scanning Electron Microscopy And Cryofracture Technique To The Study Of Cerebellar Synaptic Junctions, Orlando J. Castejón

Scanning Microscopy

The cerebelli of teleost fishes, primates and humans were processed for conventional and high resolution scanning electron microscopy (SEM) to study the outer and inner surfaces of axo-dendritic, glomerular and axo-somatic synapses. The cryofracture technique, either by slow or fast freezing, exposed the hidden neuronal surfaces of synaptic connections, selectively removing the glial ensheathment. Axo-dendritic junctions of climbing fibers and Golgi axonal ramifications were studied in gold-palladium and chromium coated samples. Chromium coating showed different mass density and topographic contrast between axonal and dendritic profiles. Conventional SEM of cryofractured glomerular synapses exhibited the outer surface view of en passant mossy …

Dental Abnormalities And Early Diagnosis Of Hyperphosphatasemia, M. J. Bottero-Cornillac, A. Gaucher, C. Wang, M. Chaussidon, J. Yvon

Scanning Microscopy

Dental hard tissue abnormalities have never been described as part of the symptoms associated with hyperphosphatasemia. Fourteen teeth obtained from a young man, who had a mild form of hyperphosphatasemia, were analyzed using scanning electron microscopy (SEM), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), and infrared (IR) spectroscopy. SEM revealed a thin enamel, presenting a prismatic structure with many pits, and atypical cementum and dentin showing numerous resorption areas. The X-ray diffractograms revealed poorly crystallinehydroxyapatite associated with α-tricalcium phosphate and magnesium hydroxide phases. SIMS data showed high Ca concentrations: 40.5 weight % {wt%; standard deviation (SD) = 0.13) …

Microvascular Corrosion Casting In The Study Of Tumor Vascularity: A Review, M. A. Konerding, A. J. Miodonski, A. Lametschwandtner

Scanning Microscopy

Tumor blood flow is dependent on the structure and three-dimensional (3-D) architecture of the vascular network. The latter can be best studied by scanning electron microscopy of microvascular corrosion casts. However, literature reviews show that nearly all studies using this technique render comparisons of different tumors more difficult since they are mainly based on descriptive terms that might lead to misunderstandings. Qualitative comparisons of 13 experimental and 3 human primary tumors of different origin show a high degree of similarity in the vasculature. Quantitative analysis of these casts reveals similar ranges of parameters such as diameters, intervascular and interbranching distances. …

Endoarticular Loose Bodies And Calcifications Of The Disk Of The Temporomandibular Joint: Morphological Features And Chemical Composition, C. Piacentini, C. Marchetti, A. Callegari, M. Setti, G. Bernasconi, U. Baciliero, P. Menghini, C. Brusotti

Scanning Microscopy

We studied articular disks and endoarticular loose bodies taken from patients suffering from different types of temporomandibular joint (TMJ) pathology. The scanning electron microscopy (SEM) analysis of the disks and the endoarticular loose bodies was followed by a chemical-compositional analysis using an energy dispersive spectrometer (EDS) and by characterization of the crystalline phases by X-ray powder diffraction (XRD). The articular disks were composed of a central radio-opaque area lacking any evident structural features, surrounded by compact bundles of collagen fibers. EDS and XRD analyses showed that endodiscal radio-opaque areas were hydroxyapatite. By SEM, we observed a fibrous network only in …

Crystalline Composition Of Equine Urinary Sabulous Deposits, M. Díaz-Espiñeira, E. Escolar, J. Bellanato, J. A. Medina

Scanning Microscopy

The composition and crystal morphology of 141 equine sabulous deposits were determined by infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The IR analysis revealed that all investigated deposits contained calcium carbonates (calcite, CaCO₃, and/or vaterite, CaCO₃) as major constituents; 42 samples were composed of calcite and vaterite, 33 of calcite, 18 of calcite/vaterite and calcium oxalate, and 17 of vaterite. The remaining specimens contained calcite/vaterite and other compounds (calcium phosphates, sulphate and/or oxalates and/or silica). The examination of 44 selected samples by means of SEM/EDX, revealed the characteristic morphology and …

Morphological Effects Of Glycosaminoglycans On Calcium Oxalate Monohydrate Crystals, Y. Shirane, Y. Kurokawa, Y. Sumiyoshi, S. Kagawa

Scanning Microscopy

The effects of individual glycosaminoglycan (GAG) species on calcium oxalate monohydrate (COM) crystal growth were studied in vitro by the observation of crystal morphology grown in a supersaturated calcium oxalate solution in the presence of GAGs using optical and scanning electron microscopes. GAGs affected the morphology of COM crystals differently depending on the species. The growth rates of the crystals formed in the presence of chondroitin-6-sulfate (ChS-C) were higher in length and lower in width and thickness than those of control crystals. The incorporation of dermatan sulfate or heparin into the crystals formed in the presence of these GAGs was …

Vitamin B6 Deficiency And Galactose Induced Alterations In Morphology And Osmotic Fragility Of Rat Erythrocytes, P. Kaul, H. Sidhu, S. K. Thind, S. K. Sharma, R. Nath

Scanning Microscopy

Recently, red blood cells have been investigated mainly for alterations in ion transporting capacity, membrane bound enzymes or modifications in the structure of its individual constituents in clinical and experimental urolithiasis. However, the implication of such modifications on the physical state or morphology of cells has not been investigated. Scanning electron microscopic studies performed in vitamin B₆ deficient and/or galactose fed rat (established hyperoxaluric models) erythrocytes, showed the presence of large number of stomatocytes, spherocytes and other variously deformed cells as compared to discocytic cells seen in normal control group. These changes in shape were in concurrence with red …

The Formation Of Filopodia-Like Protrusions During Preparation Of Cell Suspensions For Scanning Electron Microscopy, Yuri A. Rovensky

Scanning Microscopy

The standard preparation of cell suspensions (e.g., blood cells, cell suspensions derived from monolayer cultures or from various tissues, etc.) for scanning electron microscopy (SEM) includes fixation of the cells in suspension and subsequent dehydration and critical point drying (CPD) of the cells after their preliminary attachment to the special substrata. In the course of the SEM examination of cell suspensions of various origins, unusual morphological cell surface structures, filopodia-like protrusions (FLP), were consistently detected in 3-20% of the cells in the populations. FLP can be effectively observed only by using a stage tilt angle of no less than 30°. …

Backscattered Electron Imaging And Energy-Dispersive X-Ray Microanalysis Studies Of Evidence For Calcium Salt Heterogeneity In Fifteen Gallstones From An Elderly Human, Tetsuo Kodaka, Ryoichi Mori, Kazuhiro Debari, Reiji Takiguchi, Shohei Higashi

Scanning Microscopy

We examined 15 variably-sized gallstones, taken from an elderly male, by backscattered electron imaging and energy-dispersive X-ray microanalysis to learn the structural and distribution patterns of gallstone calcium (Ca-) salts. Of the 13 cholesterol-rich stones, nine stones had peripheral concentric layers of Ca-carbonate, whereas 2 stones had peripheral layers of Ca-phosphate. No Ca-salts were detected from 2 cholesterol-rich stones. The 2 stones containing Ca-phosphate had no Ca-salt cores, whereas the stones containing Ca-carbonate were separated into 3 different types: two stones with a Ca-carbonate core, four stones with several Ca-bilirubinate cores of glass-like structure, and 3 stones lacking Ca-salt cores. …

Improved Methods For Preserving Macromolecular Structures And Visualizing Them By Fluorescence And Scanning Electron Microscopy, Paul B. Bell Jr., Barbara Safiejko-Mroczka

Scanning Microscopy

To determine the optimal procedures to preserve cytoskeletal and other macromolecular structures for microscopic studies we have evaluated the effects of various methods to extract cultured cells. In this report, we compare results using different fixatives, crosslinking reagents, and permeabilization methods on (1) the labeling of cells for fluorescence microscopy with phalloidin or antibody against tubulin; and (2) the morphological preservation of macromolecular structures for scanning electron microscopy. Maximal labeling of F-actin with phalloidin was obtained by fixing cells in 4% para formaldehyde (PFA) and labeling the unextracted cells with methanolic phalloidin, whereas maximal labeling of tubulin required prefixation with …

Scanning Electron Microscopy And Energy Dispersive Spectroscopy Analysis Of Calciotraumatic Lines In Rat Labial Dentin After Acute Exposure To Strontium Chloride, Hiroyuki Mishima, Toshiro Sakae, Yukishige Kozawa

Scanning Microscopy

Rats were given strontium chloride (SrCli) intraperitoneally at a dose of 500 mg/kg. The upper incisors were removed after injection of strontium. These incisors were studied by scanning electron microscopy - energy dispersive spectroscopy analysis (SEM-EDS) and light microscopy to examine the calciotraumatic lines of strontium in the rat incisor labial dentin.

At 24 hours after injection of strontium, the calciotraumatic response was observed in the predentin using hematoxylin and eosin (H-E) staining. At 5 days, three layers of calciotraurnatic lines were present in the labial dentin using an H-E staining and backscattered electron imaging in the SEM. The external …

Scanning Electron Microscope Study Of The Healing Molar Tooth Extraction Socket In The Rat, M. D. Mcmillan

Scanning Microscopy

Healing molar tooth extraction wounds in rats were examined by scanning electron microscopy from 15 minutes to 40 days following tooth removal. The wound epithelium, which was derived mainly from the gingiva but also from the cheek and hard palate, migrated be-neath the superficial socket contents. The contents were lost between 5 to 11 days, thus leaving a central epithelial-lined depression. This decreased in width with time as the level of the wound epithelium approached that of the hard palate but was still present at 40 days. Between 5 and 7 days, the wound epithelium became more regular. However, from …

The Influence Of 5-Fluorouracil On The Endothelium In Small Arteries. An Electron Microscopic Study In Rabbits, M. Cwikiel, B. Zhang, J. Eskilsson, J. B. Wieslander, M. Albertsson

Scanning Microscopy

5-Fluorouracil (5-FU) is a widely used antineoplastic agent. 5-FU induced cardiotoxicity is a still relatively unknown side-effect of this drug. This phenomenon could be due to a direct cytotoxic effect on the endothelial cells. We tested this hypothesis in an experimental study in rabbits, by scanning or transmission electron microscopic evaluation of endothelium in small arteries (the central artery of the ear) after in vivo treatment with 5-FU. Both local and systemic effects of 5-FU on endothelium were studied 15, 30, 60 and 120 minutes after intra-arterial or intraperitoneal treatment. Perfusion fixation at physiological pressure and temperature was used in …

Alterations In Mdck And Llc-Pk1 Cells Exposed To Oxalate And Calcium Oxalate Monohydrate Crystals, R. L. Hackett, P. N. Shevock, S. R. Khan

Scanning Microscopy

Structural analysis of human kidney stones reveals the presence of cellular membranes and other cell fragments. Experimentally, calcium oxalate crystallization is facilitated when an exogenous nephrotoxin is given with ethylene glycol, thus providing cellular degradation products to act as heterogenous nuclei. In this report, we tested whether oxalate alone could act as a cell toxin capable of producing damaged cells without the presence of an exogenous agent. Cultured LLC-PK₁ and MDCK cells, when exposed to 1.0 mmol KOx, a concentration at the limit of metastability for calcium oxalate nucleation, were severely damaged as measured by specific lactate dehydrogenase (LDH) …

A New Scanning Electron Microscopy Approach To The Quantification Of Bone Mineral Distribution: Backscattered Electron Image Grey-Levels Correlated To Calcium Kα-Line Intensities, P. Roschger, H. Plenk Jr., K. Klaushofer, J. Eschberger

Scanning Microscopy

The introduction of backscattered electron (BSE) imaging in scanning electron microscopy (SEM) has led to new possibilities for the evaluation of mineral distributions in bone on a microscopic level. The different grey-levels seen in the BSE-images can be used as a measure for the local mineral content of bone. In order to calibrate these BSE-grey-levels (BSE-GL) and correlate them to mineral contents, various attempts, using reference samples with known weighted mean atomic number and/or using simulated bone tissues with known hydroxyapatite concentrations, have been made. In contrast, a new approach is presented here based on measurements of the X-ray intensities …

Gold Coating Of Respiratory Cilia For Scanning Electron Microscopy, E. Toskala, J. Nuutinen, M. Rautiainen, A. Pelttari

Scanning Microscopy

The optimal thickness of gold coating of cilia for scanning electron microscopy was studied using respiratory mucosa obtained from pigs. We tested 8 different coating times, from 10 seconds to 4 minutes, which resulted in gold layer thicknesses varying from 16 ± 1 nm to 100 ± 3 nm. The thickness of the gold layer with a coating time of 60 seconds and voltage of 2.5 kV was 43 ± 5 nm. This thickness of gold layer gave good image quality without causing any electric charging. With thinner gold films, the amount of electric charging increased. When the coating time …

Scanning Electron Microscopic Observation Of Dark Cells After Streptomycin Perfusion Of The Vestibule In Guinea Pigs, Xianxi Ge, John J. Shea Jr.

Scanning Microscopy

Hearing has been stabilized in the majority of patients studied in the treatment of Meniere's disease with streptomycin. This observation suggests that effects of streptomycin may ameliorate endolymphatic hydrops, possibly by attenuating the activity of secretory tissue. The purpose of this study is to observe the dark cells of the utricle in guinea pigs after streptomycin perfusion of the vestibule. Twelve pigmented guinea pigs weighing 250-350 grams were used in this study. The vestibules in five guinea pigs were perfused monolaterally with 150 μg of streptomycin in artificial perilymph and, in seven, the vestibules were perfused only with artificial perilymph …

Semiquantitative Analysis By Scanning Electron Microscopy Of Cochlear Hair Cell Damage By Ototoxic Drugs, Takehisa Saito, Yasuhiro Manabe, Noriyuki Honda, Takechiyo Yamada, Takehito Yamamoto, Hitoshi Saito

Scanning Microscopy

The ototoxicity of cisplatin and carboplatin in the organ of Corti of the guinea pig was evaluated semiquantitatively. Damage of the stereocilia of outer hair cells (OHCs) observed by scanning electron microscopy (SEM) was classified into normal, grade 1 (10-50% loss of stereocilia), grade 2 (less than 50% remaining stereocilia), or grade 3 (missing stereocilia). The OHCs observed by light microscopy (LM) were classified as remaining or missing cells. Fifty OHCs of each row in the middle part of each turn of the cochlea were counted (a total of 150 cells per turn). Guinea pigs were administered 5 mg/kg of …

Comparison Of Cell Sediment And Surface Grown "Test Plaque" Using Scanning Electron Microscopy, S. M. Mccormack, C. M. D. Maran, K. M. Scott-Anne, D. T. Zero

Scanning Microscopy

Scanning electron microscopy was used to compare the morphology, integrity and distribution of bacterial cells in a test plaque grown on the surface of enamel with that of the cell sediment plaque routinely used in a short-term intraoral caries model. Cultures of S. mutans IB-1600 or S. sobrinus 6715-13 were grown in complex media supplemented with either 2.0% sucrose (glucan plaque) or 0.2 % glucose (non-glucan plaque). Cell sediment (CS) plaque was prepared by centrifuging the cultures after incubation, recovering the cell sediment, and spreading it on Metricel membrane filter paper. Surface grown (SG) plaque was prepared by suspending saliva-coated …

Effect Of Sodium Saccharin On The Neonatal Rat Bladder, Samuel M. Cohen, Martin Cano, Margaret K. St. John, Emily M. Garland, Mohamad Khachab, Leon B. Ellwein

Scanning Microscopy

In a two-generation bioassay, high doses of dietary sodium saccharin (NaSac) produce bladder carcinoma in rats, whereas acid saccharin (HSac) does not effect the urothelium. NaSac and HSac administered as 5% of the diet to F0 Sprague-Dawley (SD) and F344 rats, continued through to the weaned male rats for ten additional weeks. Control 3H-thymidine labeling index (LI) was high prior to and at birth (approximately 11%), declining rapidly by weaning (to < 0.2). Neither NaSac nor HSac increased proliferation through 7 days of age. NaSac increased the proliferation rate at later times, whereas HSac did not. The LI decreased to control levels in NaSac-fed rats switched to control diet after weaning and increased in control-fed rats switched to NaSac after birth or weaning. In a second experiment, 5% NaSac did not affect urothelial morphology of SD rats through 7 days. By 21 days post-birth, urothelial hyperplasia occurred in NaSac-fed rat. The LI in treated versus control was similar through gestation, with a slight difference by 7 days. LI was significantly different by 21 days post-birth, but was similar between males and females. These results provide additional evidence for the increased cell proliferative effects of NaSac during the neonatal period, but not during gestation.

Three-Dimensional Configuration Of Crypts Of Different Types Of Colorectal Adenomas, Keijiro Araki, Takuro Ogata

Scanning Microscopy

The three-dimensional configuration of isolated crypts of normal human colonic mucosa and colorectal adenomas was examined by scanning electron microscopy. For isolation of the crypts, the digestion method with HCl was used for formalin fixed tissues, and the separation method with ethylenediaminetetraacetic acid (EDT A) following ultrasonication was applied to fresh tissues. In a comparative study, the NaOH cell-maceration method, which visualized the sub-basal laminal collagen sheath, was applied. The isolated crypts from the normal colon were visualized as a single straight tubule resembling a test tube. Most isolated crypts of the tubular adenomas were visualized as elongated fan-like structures …

Cell Surface Changes Of Hemopoietic Cells During Normal And Leukemic Differentiation: An Immuno-Scanning Electron Microscopy Study, D. Soligo, E. P. De Harven, N. Quirici, L. Caneva, G. Lambertenghi Deliliers

Scanning Microscopy

Hemopoietic cells display a wide range of cell surface antigens which are either lineage specific or acquired during differentiation. Monoclonal antibodies can be used, in conjunction with colloidal gold markers, to identify under the scanning electron microscopy (SEM) at the single cell level, specific lineage or maturation stages in the hemopoietic bone marrow. Normal bone marrow cells, either gradient separated or purified by immuno-magnetic methods and leukemic cell samples, which can be considered as "frozen" stages of hemopoietic differentiation, have been studied with this method. Typical cell surface morphologies, which characterize immature progenitor cells and cells committed or differentiated towards …

Etiology Of Calcium Oxalate Nephrolithiasis In Rats. Ii. The Role Of The Papilla In Stone Formation, W. C. De Bruijn, E. R. Boevé, P. R. W. A. Van Run, P. P. M. C. Van Miert, R. De Water, J. C. Romijn, C. F. Verkoelen, L. C. Cao, J. M. Van 'T Noordende, F. H. Schröder

Scanning Microscopy

In kidneys of healthy rats submitted to a crystal-inducing diet (CID) with ethylene glycol (EG) and NH₄Cl, the fate of retained crystals in the papillar region is studied during a recovery period of one, five or ten days, as model system for human nephrolithiasis. Scanning electron microscopy (SEM) shows, at papillary tips bulging into the calycine space, crystal masses covered either by the epithelium or a thin fibrous veil, or by unidentified mobile cuboidal cells. After CID plus one or five days recovery, small sub-epithelial swellings are seen of large sub-epithelial crystals at or around the papillary tip. …

Notes On The Microstructure Of The Nautilus Shell, P. R. Mitchell, P. P. Phakey

Scanning Microscopy

The shell of the Nautilus was examined using scanning electron microscopy, transmission electron microscopy and polarized light microscopy. The structure consisted of two major layers: a porcellaneous outer layer and a nacreous inner layer. Most of the porcellaneous layer was composed of granular crystals randomly distributed with a substructure suggestive of bundles of acicular crystallites. A separate prismatic sublayer of the porcellaneous material was composed of a more regular arrangement of crystals. The nacre was composed of alternating crystalline lamellae and films of organic material. The lamellae were formed of many polygonal crystal platelets. The growth surface of the nacre …

Revascularization Of An Excisional Wound In Gingiva And Oral Mucosa. A Scanning Electron Microscopic Study Using Corrosion Casts In Rats, Nils J. Selliseth, Knut A. Selvig

Scanning Microscopy

The purpose of this study was to examine microvascular regeneration associated with gingival wound healing. A full-thickness piece of gingiva and oral mucosa was excised along the palatal aspect of the right maxillary first and second molars in 20 young Wistar rats. The contralateral side served as unoperated control. After 2, 4, 7, 10 or 20 days of healing, microvascular corrosion casts were produced and examined by scanning electron microscopy. At 2 days, vessels surrounding the wound were dilated and impressions representing sites of leukocyte margination were prominent in the walls of venules. Capillary buds were emerging from venules and …

Ultrastructure Of Dentin Matrix In Heritable Dentin Defects, J. Waltimo, H. Ranta, P. -L. Lukinmaa

Scanning Microscopy

Heritable dentin defects form a group of diseases which exclusively affect dentin among the various dental tissues. While one type is associated with the generalized connective tissue disorder, osteogenesis imperfecta, other types occur as single traits. The clinical manifestations of the dentin defects vary from insignificant to severe enough to cause aesthetical and functional failure of the teeth. Scanning and transmission electron microscopic studies, reviewed in this paper, have markedly clarified the ultrastructure of the aberrant dentin matrix. Both similar and different changes seem to occur in the various forms of heritable dentin defects. Abnormalities in the appearance and organization …

Scanning Electron Microscopic Study Of The Collagen Sheath Of The Human Thyroid Gland And Its Disorders, Masao Morita, Takuro Ogata, Keijiro Araki

Scanning Microscopy

A cell-maceration/scanning electron microscope (SEM) method was employed to demonstrate the collagen sheath around follicles (perifollicular sheath) of the human thyroid gland and its disorders. In the normal thyroid gland, the follicles were surrounded by spherical collagen sheaths composed of a framework of thick collagen bands 1-5 μm in width and fine solitary collagen fibrils 50-70 nm in diameter. In benign thyroid diseases (Graves' disease, Hashimoto's thyroiditis and adenomatous goiter), the perifollicular sheaths differed in size and in shape according to the disease, but they were always composed of thick collagen bands and fine fibrils as in the normal thyroid. …