Life Sciences Commons^™

Ninety Degree Tilt Module And Double-Sided Stub For Scanning Electron Microscopy, G. L. C. Mcturk

Scanning Electron Microscopy

A simple inexpensive device to achieve ninety degree tilt in some scanning electron microscopes (SEM) not equipped with this facility. A new method of safely mounting and studying both sides of the same fragile flat specimen, without the hazards of remounting; used in conjunction with this device.

Preparation Methods For Light Microscopic And Ultrastructural Studies Of Fetal Rat Bladder, M. Cano, S. L. Johansson, R. B. Wilson, L. B. Ellwein, T. Sakata, S. M. Cohen

Scanning Electron Microscopy

Little is known about in utero urinary bladder embryogenesis and the development of the urothelium of laboratory animals. Previous scanning and transmission electron microscopy studies in rats and mice have indicated that the highly specialized superficial cells of the urothelium complete their differentiation at a very late stage of fetal development or shortly after birth. Limitations in methodology in the past have precluded extensive examination of earlier stages of bladder development. Innovations in preparatory procedures of the bladder of rat fetuses have been developed which make possible detailed scanning and transmission electron microscopic and light microscopic examination of cloaca and …

Basal Lamina At The Epithelial-Connective Tissue Junction In The Rat Forestomach, Esophagus, Tongue And Palate: Scanning Electron Microscopic Study, Merideth T. Hull, K. A. Warfel

Scanning Electron Microscopy

The squamous epithelium lining the rat foregut was removed by incubating fresh, unfixed specimens in 2N sodium bromide. The surface morphology of the exposed subepithelial basal lamina was examined by scanning electron microscopy. Areas examined included hard and soft palates, oropharynx, tongue, esophagus, and forestomach. The basal lamina was continuous over all surfaces. Basal lamina corrugations were not present at all sites. The saucer-like defects of lymphocyte migration that are present in the basal lamina beneath the squamous epithelium of the skin were not observed in rat foregut. The epithelial-connective tissue interface of the rat esophagus does not have the …

Scanning Electron Microscopy Of Thebesian Ostia (Microdissection By Ultrasonication: Enzymatic Digestion), F. A. Rosinia, F. N. Low

Scanning Electron Microscopy

Thebesian vasculature provides for communication between the coronary system and the chambers of the heart. Anatomic, embryologic, physiologic, and therapeutic investigations have involved this component of cardiac anatomy from the early 18th century to the present time. The scanning electron microscope (SEM) now affords an innovative approach to the study of the ostia of these veins as they open into the chambers of the heart. The surface of the intact endocardium is continuous, whether it is treated with boric acid or not, as long as it remains intact. Enzymatic microdissection of tissues with trypsin, hyaluronidase and pronase, followed by similar …

Surface Ultrastructure Of Human Megakaryocytes Sorted On The Basis Of Dna Content, M. A. Weller, J. Szela, M. I. Barnhart, A. Nakeff

Scanning Electron Microscopy

The relationship of polyploidization (DNA content) to differentiation is not well defined. We have developed centrifugal elutriation and Percoll density gradient centrifugation to obtain larye numbers of highly-purified mega-karyocytes which subsequently were stained for DNA content with Hoechst 33342 and sorted by FACS into SC, 16C and 32C ploidy classes for correlated analysis of cell surface structures by scanning electron microscopy. Each ploidy class revealed unique surface characteristics that reflect differentiation occurring in megakaryocytes independent of their DNA content.

The Gill Arch Of The Striped Bass, Morone Saxatilis. Ii. Microvasculature Studied With Vascular Corrosion Casting And Scanning Electron Microscopy, Judy A. C. King, F. E. Hossler

Scanning Electron Microscopy

The gill vasculature of euryhaline striped bass, Morone saxatilis, was examined by scanning electron microscopy of corrosion casts prepared by injecting resin (either Mercox/Sevriton or L.R. White) into the ventral aorta. The vasculature of the striped bass gill appears to be similar to that of other euryhaline species. The striped bass gill has three major vascular systems: (1) a respiratory system, (2) an arterio-venous system, and (3) a nutritive system. In the respiratory system, blood from the afferent branchial artery flows to each filament via an afferent filamental artery, and from there to the highly vascularized respiratory lamellae. Lamellar …

Anatomy And Morphometry Of Myocardial Capillaries Studied With Vascular Corrosion Casting And Scanning Electron Microscopy: A Method For Rat Heart, F. E. Hossler, J. E. Douglas, L. E. Douglas

Scanning Electron Microscopy

The present paper describes a procedure for preparing vascular corrosion casts of rat myocardial microvasculature. Essential components of the procedure include: partial "self clearing" of the heart in vitro; cardiac arrest by infusion of KCl; retrograde aortic root infusion of Mercox-Sevriton casting resin; KOH digestion of ventricular tissue; and desiccation and mounting of casts for scanning electron microscopy. About 50% of rats yielded complete casts. Vasculature closely paralleled muscle fiber orientation. Capillary beds characteristically exhibited branching, many intercapillary cross bridges, and occasional coil-ing. Average capillary cast diameter (5.6 μm) and intercapillary distance (15 μm) are comparable to results from in …

Use Of Cryogenically Prepared Samples In The Scanning Electron Microscopic Study Of Dry-To-Wet Transitions, John N. A. Lott, Patrice Kerr

Scanning Electron Microscopy

Cryogenic preparation has been used to study changes that occur as a dry specimen undergoes hydration. Conventional techniques such as critical point drying or anhydrous fixation are unsuitable for studying such changes. Seed tissue, a dry moss and various foods were chosen to show dry-to-wet transitions that take place after wetting of the dry sample begins. Cryogenically prepared specimens have great potential, not only in the study of changes which occur during imbibition of one sample, but also in the study of samples with different moisture content.

Scanning Electron Microscopic Features Of Spleen In The Rat And Human: A Comparative Study, S. Sasou, R. Satodate, T. Masuda, K. Takayama

Scanning Electron Microscopy

The marginal zone, white pulp and red pulp of rat and human spleen were studied by scanning electron microscopy and were compared. The marginal zone was observed in both species. The arterial termination in the marginal zone was quite different between both species. The follicular arteries terminated at the boundary of the white pulp and formed a vascular net regarded as the marginal sinus in rat. On the other hand, numerous arterial termini of the follicular and sheathed arteries were scatteringly found in the marginal zone in man. The central artery was surrounded with flat reticular cells in rat and …

Struvite Crystalluria And Urolithiasis In Cross Labradors, A. L. Rodgers, R. A. Irving, M. Mezzabotta, P. Benloulou

Scanning Electron Microscopy

Recurrent struvite crystalluria and urolithiasis in a Cross-Labrador bitch was studied using a combined Coulter-Counter and scanning electron microscope (SEM) approach. Staphylococcus bacteria were cultured from the patient's urine as well as from the calculi themselves. Urine samples were subjected to particle counting and sizing during active and non-active periods of stone formation. Size distribution curves so obtained were identical as were those derived from sterile and non-sterile specimens. These showed a peak incidence at a diameter of 5 μm. Particle sizes for 6 controls were also determined and showed an even distribution over a much wider range with small …

Crystalluria And Urolithiasis In A Relatively Stone-Free Population, Allen L. Rodgers, Daniel P. De Klerk

Scanning Electron Microscopy

The occurrence of renal stone in South African blacks is extremely rare. Whites however are prone to calculi to the same extent as that reported in other Western communities. The nature of the particulate material and crystalluria in urine samples from the two population groups were investigated using a Coulter Counter and scanning electron microscope. In addition, 10 calculi obtained from black patients over a 5 year period were analysed.

The particle size distribution curves obtained for normal black and white males were identical. The curves for normal black and white females were also identical but different from those for …

Microcorrosion Casting Of The Human Respiratory Acinus, S. A. Dilly

Scanning Electron Microscopy

Microcorrosion casts demonstrating the respiratory acini of human lungs were produced using Tensol Cement No. 70 (a methyl methacrylate mixture). Lung casts were made from foetuses of 19 weeks' gestation to term, a child of 5 years and two adults. Tensol Cement No. 70 was found to infuse the most peripheral airspaces without tissue penetration and could be airdried. Attempts using Batson's medium were hampered by permeation of the airway walls and inability to withstand airdrying. Despite the use of autopsy material, good cell impressions were seen.

At 19 weeks' gestation, the respiratory acinus is simple with only two or …

Ciliated Cells Of The Trachea Of The Rabbit, Treated With Cis-Diamminedichloroplatinum (Ii) Alone, Or In Combination With Ionizing Radiation, M. Albertsson, C. H. Hakansson, C. Mercke

Scanning Electron Microscopy

The ciliated epithelium of the rabbit trachea was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy (TD: 2, 6, 10, 16, or 20 Gy). Fifteen to forty-five minutes before start of the first irradiation ( treatment day 1) , 5 mg cis-DDP was given by intraperitoneal injection to each rabbit. Examination was made 1-10 days after each fractionation schedule, when specimens were ta ken for investigations.

Scanning electron microscope investigations showed a gradual development of ciliary damage from blebs on the cilia to swollen tips, broken and bent cilia and finally an epithelial lining …

Intrauterine Device (Iud) Associated Pathology: A Review Of Pathogenic Mechanisms, Waldemar A. Schmidt, Karmen L. Schmidt

Scanning Electron Microscopy

This paper summarizes our studies of IUD-related disease with those previously published by others. Our data are based upon 51 IUDs and 42 index cases of IUD-related disease demonstrating specific processes. Gross, dissecting microscope, scanning electron microscope and X-ray microanalysis examinations were made of selected IUDs and associated tissues. Tissue associated with the IUDs revealed inflammation in 59.4%, calcific material in 6.3% and no abnormality in 34.4%. JUD-associated tissue responses were accompanied by changes of the IUD; these changes involved deposition of substances upon the IUD surface and degradation of the JUD itself. Disintegration of the IUD, its string or …

Scanning And Transmission Electron Microscopic Study Of Recovered Porcine Aortic Valved Conduits, D. J. Allen, I. H. Fentie, J. T. Davis, Angela Lineen

Scanning Electron Microscopy

Four explanted porcine aortic valved conduits were examined using scanning and transmission electron microscopy. Sources of obstruction such as neointima or "peel" and calcification were observed. In one sample the neointima was found to possess an unusually large expanse of squamous cells partially lining the luminal surface. This lining much resembled a normal endothelium, which is not an expected feature of neointima. Cells, presumably of host origin, were noted upon the leaflet surfaces. They did not seem as well organized as those found on the neointima. Calcification did not seem greatly advanced but was clearly apparent. Certain treatments proposed by …

Intracellular Structure Of The Outer Hair Cell Of The Organ Of Corti, Y. Harada, T. Sakai, N. Tagashira, M. Suzuki

Scanning Electron Microscopy

The intracellular structure of the outer hair cells of the normal guinea pig organ of Corti was investigated three dimensionally by scanning electron microscope. Freeze fracturing technique followed by maceration with a 0.1% OsO₄ solution (osmic maceration method) was used. Among the cell organelles, the endoplasmic reticulum (ER) showed the most interesting features, such as subsurface cisternae and lamellar bodies. The subsurface cisterna which formed a stratiform network covered the inner surface of the cell membrane and the stratiform structure disappeared at the infranuclear region. Variously shaped mitochondria (spherical, cylindrical and branched) were found on the innermost layer of …

Scanning Electron Microscopic Observation Of The Crista Ampullaris, Y. Harada, M. Takumida, N. Tagashira

Scanning Electron Microscopy

The crista ampullaris of the guinea pig and the bull frog were investigated by scanning electron microscopy. The crista ampullaris were freeze fractured or sheared followed by maceration with 0.1% OsO₄ solution. Following this, three-dimensional intracellular structures were observed. The mitochondria of the sensory cells varied in shape from globular to long and slender. Golgi apparatus and endoplasmic reticulum of the sensory cells were also demonstrated clearly. Nerve elements, nerve endings and synaptic structures were also observed stereoscopically.

Ultrasonic Microdissection Of Immature Intermediate Human Placental Villi As Studied By Scanning Electron Microscopy, Gregory J. Highison, F. Donald Tibbitts

Scanning Electron Microscopy

The human placenta during the first 20 weeks of gestation undergoes rapid and extensive morphological changes. Near the end of this period, the most predominant type of villus present is the immature intermediate placental villus. In order to visualize this complex structure with scanning electron microscopy (SEM), we have developed a microdissection technique to expose tissue components of the placental villus while retaining its normal histological architecture. Placental villi were initially fixed in Karnovsky's fixative, buffered formalin, or 2% osmium tetroxide solution prior to exposure to connective tissue enzymes or detergents alone or in combination. Samples were dehydrated through 100% …

Evidence For The Use Of A Diamond Drill For Bead Making In Sri-Lanka, A. J. Gwinnett, L. Gorelick

Scanning Electron Microscopy

The use of a diamond splinter turned by a bow drill to drill the quartz beads in present day Cambay, India has been documented. A group of Cambay beads were made available for study. They were compared with a similar group of quartz beads excavated in Mantai, Sri-Lanka. These were dated stratigraphically c.700-1000 A.D. Silicone impressions were made of the drill holes from selected beads from both Cambay and Mantai. These were examined by means of scanning electron microscopy. The pattern of drilling was the same, suggesting that the technique of drilling with a diamond splinter and bow drill was …

The Identification And Characterization Of Metal Wrappings In Historic Textiles Using Microscopy And Energy Dispersive X-Ray Spectrometry: Problems Associated With Identification And Characterization, N. Indictor, R. J. Koestler

Scanning Electron Microscopy

Scanning electron microscopy-energy dispersive x-ray spectrometry (SEM-EDS) has been employed for the description of metal wrapped yarns. Although considerable detail is obtainable as microphotographs, and elemental analysis is obtained with ease, caution should be exercised in interpreting results. Several unravelled samples should be examined; light microscopy should be employed prior to SEM-EDS analysis. Examination of eight specimens (six from the textile collection of the Metropolitan Museum of Art, New York; two from private collections) is described. The samples were Chinese (5), German (1), Spanish (1), Turkish (1). Difficulties encountered in describing this set of samples are enumerated.

Urolithiasis In A Patient Ingesting Pure Silica: A Scanning Electron Microscopy Study, D. B. Leusmann, J. Pohl, G. Kleinhans

Scanning Electron Microscopy

A patient who repeatedly produced urinary calculi, had consumed about 3g of cristobalite (SiO₂) per day for many years. Investigations using scanning electron microscopy revealed minute particles containing silicon in the core of the stone as well as in urine sediment. A mechanism similar to that proposed for the effect of silicon-containing drugs against gastric ulcer, may play a role in this formation of silicon-containing urinary stones.

Lack Of Regional Surface Differences In Mouse Bladder Urothelium: A Scanning Electron Microscopic Study, Kari Feren, Jon B. Reitan

Scanning Electron Microscopy

The surface structures of mouse urinary bladder epithelium, the urothelium, were examined in SEM. The entire surface area of both a moderately and a well stretched bladder were studied. No regional differences were found in either case. The moderately stretched bladder showed deep folds, while the well stretched bladder had only small folds giving the bladder an accordion-like appearance. In both bladders the typical surface structures were microridges arranged in a honeycomb-like pattern. The present study indicates that focal or regional differences found in bladders treated with chemicals or exposed to radiation are a result of the treatment itself, and …

Scanning Electron Microscopy Of The Irradiated Mouse Bladder Urothelium, Jon B. Reitan, Kari Feren

Scanning Electron Microscopy

The luminal surface of mouse bladder urothelium was studied by scanning microscopy 1 year after irradiation with 0, 10 and 20 Gy respectively. The controls that were anaesthetized only displayed surface characteristics indistinguishable from normal urothelium.

Irradiation with 10 Gy did not result in marked overall changes in the scanning electron microscopic features of the luminal aspect, but in some areas alterations comparable to the alterations after 20 Gy were observed. After irradiation with 20 Gy focal hyperplastic areas, superficial early ulceration and dedifferentiation of cover cells were seen. The dedifferentiation to featureless cells is probably not associated with increased …

Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna

Scanning Electron Microscopy

The glomerular complexity of several species of birds and reptiles is investigated in this study by scanning electron microscopy of vascular corrosion casts. Comparing these results with those of a freshwater teleost and a mammalian species, a trend towards small, simple glomeruli of the avian type, beginning with large, well vascularized glomeruli resembling the type found in fish, can be observed in reptiles.

A close correlation between glomerular size and habitat can be established comparing related species having a similar physiological mode of renal function.

Entirely different from this sauropsidian evolutionary line of development is the highly complex, large differentiation …

Computer Simulation And Experimental Performance Data For An Electron Spectrometer For Electron Beam Testing Of Integrated Circuits, D. Deutges, S. Görlich, E. Kubalek

Scanning Electron Microscopy

Electron beam testing using voltage contrast in the scanning electron microscope has been established as a useful tool for nondestructive and nonloading functional testing and failure analysis of integrated circuits (IC). The accuracy of quantitative voltage measurements within the IC with the electron beam probe is determined by the performance of the secondary electron (SE) spectrometer used.

For simulating the performance of SE-spectrometers a program-package has been developed by aid of which the voltage-and field-distributions within the spectrometers can be evaluated using a finite element method. Thus it is possible to trace electron trajectories throughout the spectrometer. By considering a …

Scanning Electron Microscopic Studies On Microvascular Architecture Of Human Coronary Vessels By Corrosion Casts: Normal And Focal Necrosis, T. Ono, Y. Shimohara, K. Okada, S. Irino

Scanning Electron Microscopy

Microvascular architecture of the normal human heart and myocardial focal necrosis were studied by scanning electron microscopy of corrosion casts. Casts macroscopically identical in form to the left ventricular posterior wall were prepared.

The following results were obtained in the normal human heart. (I) Most of the arterioles communicated with capillary plexuses smoothly and straight forwardly in the left ventricular posterior free wall. (2) Arterioles which branched from the arteries ran in various directions and continued into capillaries either at right angles or obliquely in the trabeculae carneae. (3) capillaries running parallel with the cardiac muscle fibers ran in different …

Surface Studies Of Duodenal Lesions Induced By Thoracic Irradiation, K. E. Carr, S. Ellis, A. Michalowski

Scanning Electron Microscopy

Acute duodenal ulcers are produced in mice as a remote ("abscopal") effect of irradiation to the lower mediastinum. Such lesions have been examined with scanning electron microscopy at 5, 8 and 28 days after irradiation with 18 Gy of X-rays. All the ulcers occur within the first 1 cm long segment of the duodenum which is endowed with Brunner's glands. The single lesions vary in size, shape and position. The damaged area often includes much of the duodenal circumference and is distinguished by conical or rudimentary villi, or even by the complete absence of villi. In contrast, around the periphery …

Scanning Electron Microscopy Of Human Metaphase Chromosomes, T. D. Allen, E. M. Jack, C. J. Harrison, D. Claugher

Scanning Electron Microscopy

Preparative methods for scanning electron microscopy of chromosomes are dependent on the original source of material. Chromosomes extracted from unfixed metaphase cells via isolation buffers tend to show topography and surface morphology which may have been induced by the choice of isolation buffer itself. Furthermore, this type of preparation often precludes any chromosome identification, as many metaphases have been pooled, and also the chromosomes from these preparations are not suitable for the banding techniques regularly used in clinical cytogenetics. Our own approach has been to use the standard cytogenetic approach, starting with methanol-acetic acid fixed, air dried metaphase spreads, allowing …

Analytical Ultra High Vacuum Scanning Electron Microscopy With Field Emission Gun For Surface Study, P. Morin, P. Abraham, C. Bablet, M. Tholomier

Scanning Electron Microscopy

Surface studies can be carried out with a scanning electron microscope (SEM) having an ultra high vacuum specimen chamber. The main application of this SEM was the micro Auger analysis, but it is also interesting to combine the usual surface study technique with SEM observations. Indeed, these latter give valuable in formation about the topographic, chemical and crystallographic aspects of the surface when the secondary, backscattered and transmission SEM modes are used. The SEM performances are increased by the use of a field emission gun, the high brightness beam of this gun gives new observation possibilities such as the imaging …

The Cathodoluminescence Mode Of The Scanning Electron Microscope: A Powerful Microcharacterization Technique, D. B. Holt, F. M. Saba

Scanning Electron Microscopy

By detecting cathodoluminescence (CL) in a scanning electron microscope (SEM), pan and monochromatic micrographs and CL spectral analyses analogous to x-ray mode point analyses can be obtained. Complete microcharacterization requires alternate examination of both micrographs and spectra. New techniques for near infra-red CL and low-temperatures to produce sharp spectra are of increasing importance. CL emission is due to electron transitions between quantum mechanical states so the radiative defects present can be unambiguously identified at liquid helium temperatures. Strongly luminescent impurities can be detected to below one part in 10⁸. This is 10⁴ times as sensitive as the …