Life Sciences Commons^™

Calcium Phosphate In Aspergillosis Of The Maxillary Sinus, Hidekuni Tanaka, Toshiro Sakae, Hiroyuki Mishima, Hirotsugu Yamamoto

Scanning Microscopy

The unique appearance of apatite in fungus balls of aspergillosis in the maxillary sinus was investigated using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray microdiffraction and Fourier transform infrared spectroscopy (FT-IR). Rod-shaped fragments with tubular structures, and globular vesicles covered with conidia were observed in the fungus balls. Massive fragments of a solid substance were demonstrated inside the fungus balls. Calcium and phosphate were detected in necrotic areas of the fungus balls by EDS. X-ray microdiffraction and FT-IR showed the presence of an apatite-like substance, but failed to demonstrate the presence of calcium oxalate crystals usually found in such …

Migration Of Epithelium During Phenytoin-Dependent Gingival Overgrowth In Mice, S. H. Ashrafi, B. Atassi, R. Erickson, T. Sabet

Scanning Microscopy

A small cavity was made in the mesiopalatal area of the maxillary first molar adjacent to the gingiva. Mice were maintained on 40 mg/kg phenytoin (or on diluent for control) by daily intraperitoneal injections. After 9 weeks, light microscopic observations revealed that in experimental mice, epithelial cells migrated towards the cavity and covered it. In controls, epithelial cell migration towards the cavity did not occur. For scanning electron microscopic (SEM) studies, specimens were fixed in 4% glutaraldehyde in 0.1 M phosphate buffer, pH 7.2, for 2 hours, dehydrated, critical point dried and coated with gold. The surface of the outer …

A Simple Empirical Calibration Of Energy Dispersive X-Ray Analysis (Edxa) On The Cornea, N. F. Schrage, K. Benz, P. Beaujean, W. -G. Burchard, M. Reim

Scanning Microscopy

Monitoring of the corneal electrolyte content is important for the study of chemical eye burns. This paper describes quantitative measurements on gelatin standards, corneas and a cornea homogenate with an energy dispersive X-ray analyzer (EDX) in the scanning electron microscope (SEM). Ten micrometers thick cryosections were freeze-dried and mounted on solid carbon supports. The applied quantification procedure was a local peak background analysis with a specifically designed computer program. Similar chemical and physical properties of gelatin, cornea homogenate, and cornea were proven by EDX-analysis and wet chemical analysis. Gelatin standards with known concentrations of different added salts showed linear correlations …

Rabbit And Human Non-Keratinising Stratified Squamous Oesophageal Epithelium Displays Similar Microridge Structure By Scanning Electron Microscopy, S. Shasha'a, G. R. Dickson, R. St. C. Gilmore, G. C. Crean, M. M. Butt, K. E. Carr

Scanning Microscopy

Since the oesophageal epithelium of common laboratory animals, rats and mice, is keratinized it is unsuitable for comparison with typical non-keratinized stratified squamous human epithelium. It is thus important to find a suitable animal model for the study of human oesophageal tissue changes. This study investigated the microridge structure of immature and adult rabbit specimens, and adult human biopsies by scanning electron microscopy and morphometry. The investigation revealed a similarity between typical squamous human and adult rabbit oesophageal mucosal epithelium. While human epithelium specimens subdivided into two other groups (non-typical squamous and non-squamous); all typical squamous human biopsies were from …

Contributions Of Electron Microscopy To The Study Of The Hypertrophic Scar And Related Lesions, C. Ward Kischer

Scanning Microscopy

Prior to 1969, only one study of the hypertrophic scar had been done using electron microscopy, and that one used electron diffraction. Since that time, studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been integral in establishing not only the characteristics of this lesion but in formulating the reasons why the scar develops and how it resolves. The first SEM studies demonstrated a homogeneous, dense dermal matrix which supported the conclusion that the hypertrophic scar and keloid reflected excess collagen. These same studies were integral in identifying the collagen nodule as the basic anatomical unit of …

Observations On The Enamel Of Odontomas, Carla Marchetti, Cesare Piacentini, Paolo Menghini, Marcella Reguzzoni

Scanning Microscopy

The morphological study of odontomas provides an alternative model for observing the formation of dental tissues, since different maturing stages are present simultaneously. Investigations were performed on decalcified samples (using light microscopy and transmission electron microscopy) and on undecalcified samples of complex odontoma enamel (using transmission electron microscopy). Simultaneous presence of prismatic enamel at various maturing stages with different structural characteristics was observed. Such enamel was sometimes associated with layers of ameloblastic cells with characteristics of cells in functional activity. In other sites, the enamel did not present a prismatic structure but it appeared as unstructured material clusters with abundant …

Scanning Electron Microscopy Of Human Esophageal Mucosa In Patients With Carcinoma Of The Esophagus, M. Cwikiel, M. Q. Yang, M. Albertsson, C. -H. Håkansson, M. Palmegren

Scanning Microscopy

Specimens taken at surgery from 15 patients with carcinoma of the esophagus were examined with scanning electron microscopy. Nine patients were treated with chemotherapy (cisplatin + 5-fluorouracil), surgery and radiotherapy; one received preoperative radiotherapy only; and the remaining five primary surgery only. Scanning electron microscopy was performed on specimens of both tumor tissue and the mucosa at least 5 cm from the tumor. In adjacent non-tumor tissue, damage due to treatment was observed in the form of changes in microridges and increased cell loss. In tumor tissue, the degree of damage was correlated to tumor response to treatment. For patients …

Characterization Of The Complex Sulfide Ore Of Sotiel (Spain) By Scanning Electron Microscopy And Electron Microprobe Analysis, Giuseppe Bonifazi, Roberto Gorga

Scanning Microscopy

This study complements a more exhaustive examination on the complex sulfide mineralization of Sotiel, (Spain), by optical microscopy and multispectral digital analysis of images. Electron microscopy analyses were carried out to document specific associations which are difficult to detect with conventional optical microscopy. This study utilizes the application of digital techniques to image processing, in an attempt to define microstructural and microtextural characteristics of the ore, since they play an important role in the subsequent beneficiation operations (i.e., flotation).

Scientific and economic information bound to complex metallogenic phenomenology and referred to particular paragenetic scenes was acquired by the study in …

Scanning Electron Microscopic Examination Of Intracanal Wall Dentin: Hand Versus Laser Treatment, H. E. Goodis, J. M. White, S. J. Marshall, G. W. Marshall Jr.

Scanning Microscopy

Conventional cleaning and shaping of root canal spaces involves the use of hand and rotary instruments with irrigation. The procedure results in the formation of a smear layer consisting of dentin shavings, organic tissue remnants and microorganisms. The laser has been suggested as an aid in root canal preparation. In this study, pulsed and continuous wave 1.06 μm wavelength Nd:YAG lasers were used to compare their abilities to clean and shape root canal spaces to conventional methods. After preparation, the test teeth were sectioned longitudinally and examined by scanning electron microscopy. The results demonstrated that the laser was capable of …

Three-Dimensional Cytoskeletal Structures Of The Chinchilla Organ Of Corti: Scanning Electron Microscopy Application Of The Polyethylene Glycol Method, A. Nagasawa, R. V. Harrison, R. J. Mount, Y. Harada

Scanning Microscopy

We describe the application of a polyethylene glycol (PEG) embedding technique to examine the sensory and supporting structures of the inner ear. The chinchilla organ of Corti was exposed by cracking PEG embedded cochleas. A range of PEG molecular weights (2000-8000) were utilized; PEG 2000, with a melting point of 57°C was preferred. After removal of the PEG, the three-dimensional aspects of intracellular structures were observed using scanning electron microscopy. Filamentous elements in the hair cell cuticular plate and in the supporting cells were clearly observed, as was the mesh work of cross-linked actin filaments in the cuticular portion of …

Sample Preparation Techniques For Conventional And High Resolution Scanning Electron Microscopy Of The Central Nervous System. The Cerebellum As A Model, Orlando J. Castejon

Scanning Microscopy

In the present paper some basic sample preparation techniques for scanning electron microscopy of nervous tissue are described. These basic preparative methods include conventional scanning electron microscopy or slicing technique, ethanol-cryofracturing technique, freeze-fracture method using either liquid nitrogen (slow freezing) or Freon 22 cooled by liquid nitrogen (fast freezing), improved freeze-fracture method with delicate specimen preparation and chromium coating, ultrasonic microdissection, and "creative tearing" technique. Some basic principles, advantages and limitations are critically considered. In addition, some specific applications in neurobiological research are reported. Emphasis is placed upon understanding the sources and nature of artifacts that are likely to be …

Scanning Electron Microscopy Of 2,8-Dihydroxyadenine Crystals And Stones, P. Winter, A. Hesse, K. Klocke, R. M. Schaefer

Scanning Microscopy

The lack of purine salvage enzyme, adenine phosphoribosyltransferase (APRT), leads to 2,8-dihydroxyadenine stone formation and/or crystalluria because it is insoluble in urine. Urolithiasis composed of 2,8-dihydroxyadenine is not only formed in a complete defect of APRT, but also in a partial deficiency of this enzyme. The defect is inherited as an autosomal recessive trait, the homozygous state is associated with high urinary levels of 2,8-dihydroxyadenine and with crystalluria, calculus formation, and potential nephrotoxicity. Determination of the APRT activity will facilitate quantification of the enzyme deficiency and elucidation of the hereditary history. 2,8-dihydroxyadenine excretion in the 24-hour urine and its circadian …

Casting With Mercox-Methylmethacrylic Acid Mixtures Causes Plastic Sheets On Elastic Arteries. A Scanning And Transmission Electron Microscopic Study, Seyedhossein Aharinejad, Peter Böck

Scanning Microscopy

Lungs and systemic vessels of rats were cast with Mercox, both undiluted and diluted with monomeric methylmethycrylate (MMA; v:v/4:1), and studied by scanning electron microscopy (SEM). A sheet, less than 5 μm thick, surrounded the surface of cast pulmonary arteries and the aorta, when using diluted Mercox. This envelope was absent when casts were prepared with undiluted Mercox. Transmission electron microscopy (TEM) of unmacerated cast arteries showed all constituents of the vascular wall. Sections of thoroughly macerated vascular casts, however, still showed elastic lamellae in the vascular wall region, whereas muscular components and endothelial lining were completely digested. It is …

Evaluation Of The Use Of Tannic Acid In Preparation Of The Rabbit Knee Meniscus For Scanning Electron Microscopy, Daniel Levanon, Haim Stein

Scanning Microscopy

The femoral faces of medial and lateral menisci of the rabbit knee were structurally reinforced with tannic acid and studied using the scanning electron microscope. Significant improvement in preservation of the meniscal surfaces, as compared to previous studies, was brought about by the structural reinforcement technique. Menisci, although detached from tibial plateaux, retained well their shape, dimensions, and microarchitecture. Differences in surface morphology between medial and lateral menisci and between longitudinal sectors on menisci were recorded. Appearances of surface irregularities were reduced to a very low level, and the possibility that this minimum exists in situ is forwarded.

Improved Tissue Corrosion Of Vascular Casts: A Quantitative Filtration Method Used To Compare Tissue Corrosion In Various Concentrations Of Sodium And Potassium Hydroxide, Paul A. Sims, Ralph M. Albrecht

Scanning Microscopy

In this study, we compare weights of filter retained material (11 μm particle retention) after solubilization and filtration of unfixed, un-perfused tissue (fat, liver and trachea) in sodium and potassium hydroxide (1% , 5%, 10% and 20% weight/volume, w/v) at 8, 24 and 48 hour time points at 45°C. Three detergents [1% Triton-X-100 (volume/volume, v/v), 1% 7X (v/v), 1% Terg-A-Zyme (w/v)] used in combination with hydroxide were evaluated for use in solubilizing fat. Additionally, vascular casts from mouse kidneys were corroded to test the practical effectiveness of corroding solutions on resin infused tissue.

Five percent KOH for eight hours proved …

Microsporum Canis Scalp Ringworm: Its Primary Or Secondary Ectothrix Character, Hester F. Vismer

Scanning Microscopy

This study supports the view that, in cases of tinea capitis due to a Microsporum canis infection, ectothrix arthroconidium formation is extrapilary and arises from intrapilary hyphae. The hyphae of M. canis perforate and digest the hair cuticle to alter its appearance from a normally identifiable structure of imbricated cells with a distal free border, to a grossly altered and pathological layer. Conidium production mainly takes place outside the hair shaft and forms thick clusters between the cuticular tiles. Finally, a shaft of conidia is formed around the hair. The cuticular covering of such a conidium sheath belongs to the …

Keynote Paper: The Scanning Electron Microscope (Sem) Supplemented By The Polarized Light Microscope (Plm), And Vice Versa, Walter C. Mccrone

Scanning Microscopy

The scanning electron microscope (SEM) yields excellent topographic and other shape information and, when fitted with an energy dispersive system (EDS), elemental composition. The polarized light microscope (PLM) on the other hand, delivers information on the internal properties of small particles, fibers, and films. By determining optical properties as well as shape, PLM determines molecular, rather than elemental, composition. Both SEM and PLM have impressive records for problem solving in the research and development world and each is usually applied without aid from the other. Examples are given of important problems that have been solved by supplementary PLM with SEM …

The Vascularization Of The Kidney Of The Eel (Anguilla Anguilla - Osteichthyes) In The Freshwater Habitat, Hans Ditrich, Heinz Splechtna

Scanning Microscopy

The renal vascular system of eels (Anguilla anguilla L.) in freshwater has been investigated using light-, transmission electron-, and scanning electron microscopy of vascular corrosion casts and critical-point dried specimens. The morphology of the kidney exhibits a highly evolved, unpaired, spindle-shaped form. The renal tissue extends partially into a recessus dorso-caudal to the anus. Renal glomeruli are comparatively large (100.8 μm +/-17 standard deviation) and well vascularized. They are arranged in grape-like clusters around the intrarenal arteries. Closely neighbouring glomeruli can be surrounded by incompletely separated Bowman's capsules sharing the same renal tubule. The peritubular capillary plexus is …

Preparation Of Dinosaur Fossils For Scanning Electron Microscopic Evaluation Of Bone Histology, C. Barreto, R. M. Albrecht

Scanning Microscopy

The quality of preservation is a major determinant of the amount and kind of information to be derived from a paleontological specimen. Various fossilization regimes may produce specimens that contain biological information on a microscopic level. Light microscopic inspection of adolescent fossil dinosaur bones from the Two Medicine Formation (northwestern Montana) revealed that precise preservation of tissue may occur at a cellular level. In the following report, we test and compare techniques of specimen preparation for examination by scanning electron microscopy and illustrate an example of faithful preservation of dinosaur bone histology.

Scanning Electron Microscopy Of Vascular Smooth Muscle Cells From Spontaneously Hypertensive Rats, William J. Krizmanich, Robert M. K. W. Lee

Scanning Microscopy

The fine structure of vascular smooth muscle cells from large mesenteric arteries of adult (28 weeks) spontaneously hypertensive rats and Wistar-Kyoto rats was studied using scanning electron microscopy (SEM). The effect of the digestion method for SEM on tissue size and smooth muscle cell size was also studied using morphometric analysis. A significant reduction in cell size (42-43%) was present after critical point drying, based on the reduction in volume to surface ratio of smooth muscle cells. However, percent change of volume density and volume to surface ratio of smooth muscle cells after digestion and after critical point drying, was …

Scanning Electron Microscopy Of Muscle Myofibrils After High Pressure Freezing And Freeze-Substitution-Staining, M. Malecki, M. L. Greaser

Scanning Microscopy

A novel approach to study the three dimensional ultrastructure of organelles and cells by means of scanning electron microscopy is described. Muscle myofibrils have been used in the development of the techniques since their structure is well characterized using conventional electron microscopic methods. Myofibrils in rigor buffer (with no cryo-protectants or pressure sealants) were frozen at high pressure (2300 bar) within specially designed chambers. The frozen specimens were then freeze-substituted-stained with methanol containing tungsten and iron salts and finally critical point dried. These methods allowed scanning electron microscopic observations of the organization of individual filaments within whole myofibrils over several …

Application Of Scanning Electron Microscopy And X-Ray Analysis To Urinary Tract Cancer In Animals And Humans, Martin Cano, Toru Suzuki, Samuel M. Cohen

Scanning Microscopy

Scanning electron microscopy (SEM) has proven useful in various aspects of urinary bladder carcinogenesis research and these are reviewed as they pertain to our research involving sodium saccharin in the rat. Sodium saccharin-carcinogenesis in rats requires administration at high doses beginning at birth or earlier. Administration beginning at ages of 5 weeks or later results in much lower incidences of bladder tumors. Methods were developed for examining the rat fetal and neonatal bladder to further evaluate effects at these critical ages. Several significant differences were found by SEM between the fetal bladder compared to the-adult. The typical polygonal superficial cells …

Scanning Electron Microscopy Of Styrene-Methylethylketone Casts Of The Airway And The Arterial System Of The Lung, Teruyuki Hojo

Scanning Microscopy

The method of making casts of airways and the pulmonary arterial system using a styrene polymer resin is described. A human and a dog were used as models. The viscosity of this resin ranges between 40 and 60 dPa/s at 24°C. The elastic rubber tube used for resin injection allows a constant perfusion pressure, i.e., 44 mm Hg and 110 mm Hg for airway and vascular filling, respectively. The casts obtained using this method are suitable both for macro- and microscopic analysis. Shrinkage during polymerization is minimal. Moreover, a preceding lavage is not necessary. Scanning electron microscopy (SEM) of cast …

Identification Of The Physical Modification Threshold Of Dentin Induced By Neodymium And Holmium Yag Lasers Using Scanning Electron Microscopy, J. M. White, H. E. Goodis, G. W. Marshall Jr., S. J. Marshall

Scanning Microscopy

Laser application to dentin has been advocated to modify the dentin substrate for restorative procedures. We examined the minimum energy density required to physically modify the dentin surface using 1.06 μm and 1.32 μm Neodymium:Yttrium-Aluminum-Garnet (Nd: YAG) and 2.10 μm Holmium-YAG (Ho: YAG) lasers. Three millimeter thick dentin sections from the middle occlusal third of crowns of third molars were used. To determine the effect of surface preparation, the sections were ground to 240, 320, 400, 600 grit or polished to 0.5 μm. Smear layer was removed using 0.5 M EDTA for 2 minutes. Five single pulse repetitions at each …

A Few Steps Towards A More Quantitative Understanding Of Contrast In The Scanning Electron Microscope, F. Hasselbach, U. Maier

Scanning Microscopy

The interaction volume of the electron beam with the specimen in a scanning electron microscope (SEM) is a highly complex function of the surface structure of the specimen, its chemical composition and the energy of the scanning electron beam.· The video signals formed by secondary electrons (SE) or backscattered electrons (BSE) reflect this complexity insofar as they may contain not only information of the interior of the pixel which has just been scanned and its neighborhood, but may depend on surface details hundreds of microns apart from the impinging point of the electron beam. This leads to artifacts in scanning …