Biology Commons^™

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 …

Calcospherites In Rabbit Incisor Predentin, H. Mishima, Y. Kunuki, T. Sakae, Y. Kozawa, N. Watabe

Scanning Microscopy

Calcospherites from the lower incisor dentin of rabbits were investigated by scanning and transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and electron diffraction analyses. In the labial predentin, globular calcospherites of 8-31 μm were present at the root apex, decreasing in size toward the incisal region. The calcospherites at the intermediate region were of mulberry- as well as of spindle-shape of 1.5-4 μm diameter. The incisal pulp horn contained micro-calcospherites of 0.3-0.6 μmin diameter. In the lingual predentin, small granular calcospherites of 1. 8-3 μm were present at the root apex, increasing in size toward the intermediate region. Ultrathin …

Ultra-High Resolution Scanning Electron Microscopic Studies On The Sarcoplasmic Reticulum And Mitochondria In Various Muscles: A Review, Takuro Ogata, Yuichi Yamasaki

Scanning Microscopy

The three-dimensional structure of the sarcoplasmic reticulum (SR), transverse (T)-axial tubular system and mitochondria in various muscles was examined by means of ultra-high resolution scanning electron microscopy (SEM) after removal of the cytoplasmic matrices and myofilaments by the aldehyde-osmium-DMSO-osmium procedure. The striated muscles reviewed and presented are twitch and slow fibers of the frog, twitch and slow fibers of the chicken, twitch extrafusal fibers and intrafusal fibers of the rat, and cardiac muscle fibers of the rat and dog. In all of these striated muscle fibers, T-tubules run transversely and are coupled with terminal cisternae forming triads or dyads. Sarcotubules …

High-Resolution Scanning Electron Microscopy Of Rat Incisor Ameloblasts, A. Nanci, S. Zalzal, F. W. K. Kan

Scanning Microscopy

The internal three-dimensional organization of secretory and maturation stage ameloblasts was examined using field emission scanning electron microscopy. Particular attention was given to the structure of the Golgi apparatus, the distribution of smooth membrane tubulo-vesicular elements and their relationship with endosomal/lysosomal components. Rat incisors were fixed by intracardiac perfusion with glutaraldehyde, decalcified and divided into segments. The tissues were cryoprotected with glycerol and freeze-fractured. They were then macerated in osmium, and after conductive staining with osmium/tannic acid, the samples were critical-point dried and sputtered with gold. High-resolution scanning electron microscopy showed that ameloblasts contain a well-developed Golgi apparatus, even in …

The Use Of Sonic Frequencies As A Cleaning Agent Of Specimens To Be Observed By Scanning Electron Microscopy, G. Familiari, A. Familiari, G. Macchiarelli, L. J. A. Didio, P. M. Motta

Scanning Microscopy

The presence of mucus and/or cellular debris can obscure the fine morphology of the gastrointestinal or respiratory luminal surface, when observed by scanning electron microscopy. With the intent of obtaining a good cleaning of the mucosal surface without altering the ultrafine morphology of epithelial cells, a new model of sonicator/ultrasonicator is presented.

The instrument is supplied with a control system for wave frequency, amplitude and form, and permits a precise regulation of the wave energy. With this instrument it is possible to produce a "cleaning effect" by using any kind of frequency (either sonic or ultrasonic) and/or amplitude and/or waveform …

Study Of Surface Modified Poly(Ethylene) Yarns, Samuel H. Cohen, Heidi Schreuder-Gibson, John T. Stapler

Scanning Microscopy

Spectra® fibers and fabrics have been treated to enhance surface friction to determine if ballistic penetration resistance of Spectra fabric can be increased with improved interfiber friction. Scanning electron microscopy (SEM) has shown the extent of surface modification for plasma treated Spectra yarns and the uniformity of coverage for dip-coated yarns and fabrics. Of particular interest is the observation by SEM that plasma gases etch the surface of the polyethylene, producing varying effects on the fiber surface friction. While difficult to measure spectroscopically, the presence of coatings that affect fiber friction are confirmed by SEM.

Mercox®-Methylmethacrylic Acid Mixture Penetrates Into Cells. A Scanning And Transmission Electron Microscopic Study, S. Aharinejad, P. Böck

Scanning Microscopy

During preparation of vascular casts using mixtures of Mercox® and methylmethacrylic acid for scanning electron microscopy, occasionally irregular structures were observed adhering to otherwise well prepared corrosion casts. These artifacts were further analyzed in sections of cast preparations. The bizarre-shaped structures varied in size and were often tightly connected to vascular casts; they withstood KOH maceration and cleaning with formic acid. The persistence of biological material, connective tissue fibers and cells or cellular fragments, became obvious in ultrathin sections. Transmission electron microscopy also showed inhomogeneity of the polymerized casting medium (Mercox®-methylmetbacrylate mixture; v/v: 4:1). An unidentified com-pound of this resin …

Scanning Electron Microscope Observations Of Brine Shrimp Larvae From Space Shuttle Experiments, Lynnette Debell, Avelina Paulsen, Brian Spooner

Scanning Microscopy

Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays.

Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage …

Scanning Electron Microscopy Of Intracellular Organelles In The Young Odontoblasts Of Rats, Yasutomo Iwai-Liao, Yoshikage Higashi, Masakazu Ishikawa, Hideaki Hori

Scanning Microscopy

Intracellular structures of the odontoblasts were studied by scanning electron microscopy (SEM) using a modified AODO (aldehyde prefixed-osmium-DMSO-osmium) method. Well-developed flattened and layered rER (rough endoplasmic reticulum), paved with its associated ribosomes on its outer surface, were clearly observed in the odontoblast. Branched tubular mitochondria with nodules and swollen endings, interposing between and passing through the fenestrated layered rER, were demonstrated in the functional cells. Oblique and cross-sections of both the rER system and tubular mitochondria showed orthodox configurations similar to those usually described in transmission electron microscopy (TEM) studies. Many finger-like projections constructing the cristae directing towards the inner …

Microvasculature Of Normal And Hydropic Labyrinth, Yoshiaki Nakai, Haruhiko Masutani, Makoto Moriguchi, Kazuhiro Matsunaga, Akihumi Kato, Hitoshi Maeda

Scanning Microscopy

The microvasculature of the inner ear in guinea pigs and humans was observed with a scanning electron microscope using corrosion casting method. Alterations in the inner ear vasculature which occurred in association with experimental endolymphatic hydrops were also investigated. The results thus obtained are summarized as follows:

1. In the cochlea and vestibule, the arteries, coiled arterioles, and the veins are endowed with their respective characteristic morphologic features and play a role in the regulatory mechanisms of circulation.

2. The point in humans which is most different from guinea pigs was that coiled arterioles in the cochlea and the coil-like …

Techniques For Low Voltage Scanning Electron Microscopy Linewidth Measurements, Kenneth S. Maher

Scanning Microscopy

Present scanning electron microscopy (SEM) linewidth measurement systems, although "state of the art", require better defined techniques in deriving operating parameters for precision measurements. Experiments were performed to check techniques used on cleaved and uncleaved specimens, void of conductive coatings to obtain optimum SEM operating parameters, and the variations in results due to changes in system operating conditions. In addition, a method was devised to select and use different calibration standards and evaluate SEM linewidth measurement systems.

Response Of The Esophageal Epithelium To Concomitant Cis-Dichlorodiammineplatinum(Ii) And Radiation Treatment. An Electron Microscopic Study In Rabbits, M. Albertsson, M. Cwikiel, C. H. Håkansson, M. Palmegren

Scanning Microscopy

The rabbit esophageal mucosa was irradiated with daily fractions of 2 Gy up to an accumulated dose of 20 Gy (total dose 2, 6, 10. 16 or 20 Gy). Fifteen to forty-five minutes before the start of each irradiation 0.3 mg Cis-dichlorodiammineplatinum (cis-DDP, cisplatinum) was given by intraperitoneal injection to each rabbit. Examinations were carried out 1-10 days after each fractionation schedule, when specimens were taken for morphological investigations.

Scanning electron microscope (SEM) examination showed a gradual development of damage with cell loss and structural disarrangement of the microridges and whorls on the surface. However, with further treatment the esophageal …

Scanning Electron Microscopy Of Nerve Fibers In The Dog Cochlea, Hirofumi Morita, Tomoyuki Hoshino, Kunihiro Mizuta

Scanning Microscopy

The nerve fiber arrangement inside the organ of Corti in the dog was studied. Thick sections were cut serially from celloidin-embedded cochleas and observed with a scanning electron microscope (SEM). The nerve fibers in the organ of Corti were clearly exposed in sections cut in the horizontal plane. The arrangement of nerve fibers in the dog showed considerable difference from that of other species. The tunnel basilar fibers in the dog curved basalward, and took a long longitudinal course to form a broad bundle in the center of the tunnel floor. This bundle has not been found in adult animals …

The Effect On The Ultrastructure Of Dental Enamel Of Excimer-Dye, Argon-Ion And Co2 Lasers, J. Palamara, P. P. Phakey, H. J. Orams, W. A. Rachinger

Scanning Microscopy

This study aimed to investigate the ultrastructural changes that occur in dental enamel irradiated with pulsed excimer-dye, continuous-wave (CW) argon-ion and CW CO2 lasers. The pulsed excimer-dye laser produced deep craters, rough damaged surfaces with underlying porosity and amorphous vitrified material. The vitrification of the enamel indicated that the temperature in these areas must have been al least in the range 1280 to 1600°C. The CW argon-ion laser irradiation produced a changed non-cratered surface with inter-crystalline porosity and a mixture of small and some large irregularly packed recrystallized enamel crystals. The CW CO2 laser produced shallow craters, surface crazing and …

Morphological Study Of Gastric Lesions Developing In The Rat Under Several Damaging Conditions: Modifications Induced By Pretreatment With Zinc Acexamate, M. Luisa Bravo, Ginés Escolar, Carmen Navarro, Ramón Fontarnau, Oriol Bulbena

Scanning Microscopy

Lesions developing in the gastric mucosa of the rat after exposure to different gastric damaging agents (100 mg/kg aspirin, and 70% or 100% ethanol) were assessed by scanning electron microscopy. The severity of the lesions was quantified according to morphological criteria. Modifications in the severity of these lesions induced by pretreatment with zinc acexamate were also analyzed. The scanning electron microscope revealed that with the exception of absolute ethanol, which caused distinctive morphological features, lesions found under the different experimental agents shared a common pattern of progression. Ultrastructural lesions on surface epithelial cells preceded further alterations of parietal cells. After …

Electron Probe Microanalysis Of The Otolithic Membrane. A Methodological And Quantitative Study, J. A. López-Escámez, F. J. Cañizares, P. V. Crespo, A. Campos

Scanning Microscopy

The effect of tissue preparation on calcium and potassium weight percents in the otoconial layer in the utricle and saccule was studied in four groups of OF1 mice with electron probe X-ray microanalysis. Glutaraldehyde and freeze-drying, glutaraldehyde and air-drying, air-drying, and cryo-fixation and freeze-drying were compared. Ca and K changed significantly in the utricle depending on the method used (P < 0.001), and K changed significantly in the saccule (P < 0.001 ). We chose cryo-fixation with freeze-drying for the quantitative analysis of the otolithic membrane because this method provided the highest values of Ca and K with minimum loss of Ca and K . Microcrystalline salt standards mounted on scanning electron microscopy holders were used for the quantification of Ca and K by the peak-to-local-background (P/B) ratio method. The P/B ratio in standards with reproducible results, when plotted against weight percent, gave a straight line for Ca (r = 0.99, P < 0.001) and K (r = 0.98, P < 0.001). The Ca and K weight percents in otoconia showed similar frequency distributions in the utricle and saccule.

Vascular Anatomy Of The Pig Kidney Glomerulus: A Qualitative Study Of Corrosion Casts, B. J. Moore, Kenneth R. Holmes, Lisa Xuemin Xu

Scanning Microscopy

Pig kidney glomerular vascular anatomy was studied by scanning electron microscopy of vascular corrosion casts. A generalized vascular architecture is presented to describe the pig kidney glomerulus based upon the observation of 3,800 vascular cast glomeruli. The relative simplicity of the pig glomerular vascular architecture has allowed the characterization of different vascular segments more completely than has been possible in other mammals. Based upon relationships to the afferent arteriole, a nomenclature and definition of primary, secondary, tertiary and anastomotic vessels is proposed for the distributing vessels comprising the glomerular tuft. The existence and formation of a large central hemispheric vessel …

Luminal Constrictions On Corrosion Casts Of Capillaries And Postcapillary Venules In Rat Exocrine Pancreas Correspond To Pericyte Processes, Seyedhossein Aharinejad, Peter Böck

Scanning Microscopy

The rat exocrine pancreas was studied as a model to demonstrate morphological features of different types of capillaries, using scanning electron microscopy of vascular corrosion casts and transmission electron microscopy of tissue sections. Two types of capillaries were discerned. The first type represents less undulated, slender, straight capillaries with numerous, shallow, circular or semilunar furrows on its cast's surface. In tissue sections, this type probably corresponds to non-fenestrated capillaries. The numerous grooves on its cast correspond to pericyte processes beneath the endothelial lining. The second type comprises capillaries of an undulated course and variable diameter with less numerous furrows. In …

Appearance Of Venous Sphincters In The Pulmonary Microvascular Bed Of Normotensive And Spontaneously Hypertensive Rats, Seyedhossein Aharinejad, Peter Böck

Scanning Microscopy

The appearance of pulmonary venous sphincters was studied in normotensive and spontaneously hypertensive rats using scanning electron microscopy of microvascular corrosion casts and transmission electron microscopy of tissue sections. Vascular casts were prepared either after lavage with Tyrode solution or after glutaraldehyde prefixation. Pronounced pulmonary venous sphincters were more frequently identified in spontaneously hypertensive rats as compared to corresponding circular indentations in normotensive rats. Tissue sections established venous sphincters in hypertensive animals as consisting of multiple layers of smooth muscle cells in the venous walls. We did not observe any autonomic nerve terminals in close proximity to these bundles of …