Biology Commons^™

Ultrastructural Studies Of Intercellular Contacts (Junctions) In Bone Marrow. A Review, Ferrell R. Campbell

Scanning Electron Microscopy

This paper reviews ultrastructural studies of the intercellular contacts or junctions between cells of the bone marrow. Studies using tannic acid and glutaraldehyde as a fixative have shown pentalaminar complexes between many types of cells in marrow of mice and chicks. These intercellular contacts occur between adjacent stromal cells, between stromal cells and developing blood cells and, in marrow of mice, between migrating blood cells and cells of the sinusoidal wall. Because of their location and widespread occurrence, it is believed these contacts may represent a type of adherent junction helping to maintain an orderly arrangement of blood cells and …

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% …

Scanning Electron Microscopy In The Evaluation Of Consolidation Treatments For Stone, A. E. Charola, R. J. Koestler

Scanning Electron Microscopy

The use of scanning electron microscopy (SEM) examination is shown to be an important tool in the evaluation of the effectiveness of consolidant treatments in stone. This implies the visualization of the attachment of the resin to the stone, the assessment of the degree of penetration and the distribution of the resin in the stone matrix. These factors can then be correlated with the chemical nature of the stone and the resin.

A sample preparation technique for limestone, based on acid etching of the surface, is described. This technique improves the visualization of the resin within the stone.

The Characteristic Structural Features Of The Blood Vessels Of The Lewis Lung Carcinoma (A Light Microscopic And Scanning Electron Microscopic Study), T. W. Grunt, A. Lametschwandtner, K. Karrer

Scanning Electron Microscopy

Vascular corrosion casts of Lewis lung carcinomas (LLC) grown subcutaneously in C57BL/6-mice are correlated with histological sections and with tumor tissue prepared for scanning electron microscopy (SEM). By making low, medium and high pressure cast preparations we studied the influence of perfusion and injection pressure on the resulting cast sample.

Three types of vascular proliferations are distinguishable in LLC: 1) Small globular outgrowths on sinusoidal dilated tumor capillaries, caused by proliferation of their endothelial cells. 2) New sprouts on surrounding host vessels, invading the small, still avascular implant. 3) Superficially located, centrifugally running sprouts in peripheral regions of large tumors. …

The Angioarchitecture Of The Lewis Lung Carcinoma In Laboratory Mice (A Light Microscopic And Scanning Electron Microscopic Study), T. W. Grunt, A. Lametschwandtner, K. Karrer, O. Staindl

Scanning Electron Microscopy

53 Lewis lung carcinomas implanted subcutaneously into C57BL/6-mice were examined. The animals were killed at various stages of tumor growth (TG) and prepared for histology and for scanning electron microscopy (critical-point-dried tissue; vascular corrosion casts). Prior to casting animals were rinsed using different perfusion pressures. Casting was done by manual injection of the resin, whereby different influx-rates were applied resulting in low, medium and high pressure preparations.

We discern 3 phases of tumor angiogenesis (TA) occurring during 4 stages of TG among which vasodilation establishes the first reaction of the host vascular system to a growing tumor implant. During this …

Changes In Absorptive Surfaces Of Rat Visceral Yolk Sac With Increasing Gestational Age, W. P. Jollie

Scanning Electron Microscopy

The free surface of the endodermal epithelial lining of the rat visceral yolk sac was examined by scanning electron microscopy at three stages of pregnancy, viz., 12, 17 and 22 days (birth typically occurring on the 23rd day). Additionally, by ultrasonic vibration of tissues that had been subjected to prolonged osmium fixation, the epithelium was removed and such microdissected membranes similarly were examined.

With increasing gestational age the free surface of the epithelium. underwent a relative increase in absorptive area by three mechanisms: formation of increasingly complex villous projections of the visceral yolk sac as a whole, a doming of …

Weighted Silks Observed Using Energy Dispersive X-Ray Spectrometry, M. Ballard, R. J. Koestler, N. Indictor

Scanning Electron Microscopy

A group of modern silk fabrics was treated with various weighting agents as standards. These standards were observed using energy dispersive x-ray spectrometry. The standards were compared to untreated samples and to museum specimens of weighted silks. In all prepared specimens the elements expected from treatment were observed; weighting treatments could be distinguished. The analytical procedures are discussed and compared to recent work on mordant analysis using the same techniques.

Elemental And Ultrastructural Characteristics Of The Egg Capsules Of Nautilus Pompilius, R. J. Koestler, E. D. Santoro, G. Dingerkus

Scanning Electron Microscopy

Six pearly nautili (Nautilus pompilius) raised in captivity produced nonviable egg capsules which were examined using scanning electron microscopy ( SE M) and energy dispersive x-ray spectrometry (EDS). Macro and microscopic observations revealed two distinct and separate walls encircling the yolk sac. Both walls exhibited a porous appearance in cross-section. Protein analysis demonstrated the proteinaceous nature of nidimental gland secretions and egg capsule walls.

EDS analysis of each wall shows the elemental composition to be identical in both, with each wall containing similar proportions of S, CI, Mg, Na, K, and trace amounts of Ca. X-ray mapping of Na and …

Application Of Scanning Electron Microscopy To The Study Of Shark Dermal Denticles, G. Dingerkus, R. J. Koestler

Scanning Electron Microscopy

Clear, high resolution scanning electron micrographs of shark dermal denticles are essential to allow the study of their morphology and micro-relief. Various techniques were tried to remove mucus and adventitious debris, including KOH, trypsin enzyme, and ultrasonication. In most species examined the best results were obtained with enzyme treatment followed by ultrasonication. For scanning electron microscopic examination it was found that 15 nm gold coating, or more, and 10 kV, or less, had to be employed to reduce charging of the denticles.

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.

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.

Microtextures Of Laterites And Bauxites Capping Deccan Trap Basalts In Western India, D. V. Chitale, N. Güven

Scanning Electron Microscopy

Thirty-five samples of laterites and bauxites representing both the high-level (elevation > 1000 m) and low-level (elevation < 100 m) deposits in western India have been examined by scanning electron microscopy. Megascopically, laterites exhibit vesicular, spongy and pisolitic textures, whereas bauxites display pisolitic, massive and nodular textures. Laterites, as well as bauxites are commonly characterized by framework microtexture produced by a three dimensional arrangement of crystallites. Locally, the luterites and bauxites exhibit crystalline-webby microtexture formed by a web-like arrangement of stacks of lamellar crystals. The individual crystals in the matrix of laterites and bauxites display anhedral forms and they range in size from about 0.5 μm to 20 μm. Crystals larger than 20 μm in size generally occur as linings of the vugs, in channels and veins, and they are usually euhedral. Pisolites and nodules in laterites and bauxites are composed of material generally finer than the material in the matrix around them. Platy morphology is most common for the minerals in laterites and bauxites. Gibbsite occurs in various forms ranging from prismatic, stubby slab-like to lath-shaped crystals.

Both high-level and low-level deposits of laterites are characterized by similar textures. The variations in textures of bauxites are also found to be independent of the elevation of the deposits.

Embryonic Development Of The Chicken External Cloaca And Phallus, M. R. Bakst

Scanning Electron Microscopy

The use of the scanning electron microscope has provided new detailed information about the embryonic development of the chicken external cloaca and phallus and has consequently clarified the origin of the differences between the anatomy of the chicken and turkey phallus. At Day 6 (of incubation), the genital (g.) tubercle is formed in the ventral aspect of the embryo between the caudal fold of the amnion and the tail bud. On the ventral surface of the tail bud are paired g. swellings which flank the g. tubercle. Originating at the midline between the g. swellings is the g. crest which …

Quantitative Vascular Casting Of The Post-Ischemic Hydronephrotic Kidney, Vincent H. Gattone Ii, Robert D. Sale

Scanning Electron Microscopy

The renal microvasculature (afferent arteriole) and glomeruli were examined and quantitated by two methods in the post-ischemic hydronephrotic (PIH) kidney. The methods used were: 1) an in vivo examination and 2) controlled perfusion-fixation, quantitative vascular casting examined by scanning electron microscopy. The second method was also applied to the vasculature of the contralateral, functional kidney. The goals of the study were to: 1) validate the quantitative vascular casting method by comparing PIH renal microvascular data from the casting method with in vivo values and 2) determine the extent of microvascular dimensional difference of the PIH kidney from its contralateral functional …

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 …

Histochemistry Of Colloidal Iron Stained Crystal Associated Material In Urinary Stones And Experimentally Induced Intrarenal Deposits In Rats, Saeed R. Khan, Raymond L. Hackett

Scanning Electron Microscopy

Organic material associated with the calcium oxalate crystals in urinary stones and experimentally induced nephrolithiasis was stained with colloidal iron and analysed by energy dispersive x-ray microanalysis using standard techniques. Iron was positively identified in the stained specimens indicating that some of the organic material is an acidic mucosubstance. The results also indicate that some of the organic material of urinary stones may originate in the kidneys.

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 …

Immunoarchitecture Of The Regenerating Rat Spleen: Effects Of Partial Splenectomy And Heterotopic Autotransplantation, Michael C. Dugan, Thomas M. Grogan, Marlys H. Witte, Catherine Rangel, Lynne Richter, Charles L. Witte, David B. Van Wyck

Scanning Electron Microscopy

To investigate the microstructure of in situ (eutopic) and autotransplanted (ectopic) splenic remnants, adult Sprague-Dawley rats were studied 60 days after 1) subtotal (~80%) splenectomy, 2) total splenectomy followed by single or multiple remnant intraperitoneal autotransplantation, or 3) sham operation. Total nucleated cell counts were determined in excised splenic remnants, and immunohistochemical staining using monoclonal antibodies to rat B-and T-cell antigens was performed in serial tissue sections.

Immunoarchitecture of eutopic remnants was indistinguishable from that of intact spleens and total nucleated cell counts remained proportional to weight. In contrast, ectopic remnants showed sparsity and abnormal mixing of B and T …

Preparation Methods For Quantitative Electron Probe X-Ray Microanalysis Of Rat Exocrine Pancreas: A Review, N. Roos, T. Barnard

Scanning Electron Microscopy

Pancreatic acinar cells are thought to secrete a fluid containing digestive enzymes and electrolytes and use e,g, calcium as a second messenger upon stimulation, Together with their pronounced morphological polarity, they provide a model system to study the effect of different preparation methods for quantitative biological electron probe X-ray microanalysis (EPXMA) of ultrathin sections, Several preparation methods i,e,, freeze-drying and plastic-embedding, freeze-substitution (2 days) and freeze-drying of ultrathin cryosections have been applied to examine the retention of sodium, magnesium, phosphorus, sulfur, (chlorine), potassium and calcium in subcellular compartments (basal cytoplasm, apical cytoplasm, mitochondria and zymogen granules), In freeze-substituted samples the …

Use Of Electron Back Scatter Diffraction Patterns For Determination Of Crystal Symmetry Elements, D. J. Dingley, Karim Baba-Kishi

Scanning Electron Microscopy

The application of electron back scatter diffraction in the scanning electron microscope has been extended to the determination of crystal symmetry elements, point group and space group. The wide angular range of the patterns makes this a relatively simple task compared with equivalent analysis using electron channelling patterns, convergent beam patterns or standard x-ray methods, though the complexity of the analysis does not permit an unthinking approach. To establish the best procedure specimens from the seven crystal systems were investigated and results from the examination of the metal tin (tetragonal), and minerals zircon (ZrSiO₄, tetragonal) and calcite (CaCO …

Corrosion Cast Technique Applied In Lymphatic Pathways, A. Castenholz

Scanning Electron Microscopy

The paper deals with methods and results of the microcorrosion cast technique in lymph angiology. For the representation of the special organization of the lymph vascular system including the initial vascular structures, intranodal pathways, bigger collectors, and lymph trunks, the application of various injection techniques is necessary. The interstitial injection of Mercox proves to be suitable to show the initial lymphatics and prelymphatic spaces. Similarly, the intranodal injection makes visible the system of the lymph sinuses and the spaces of the reticular tissue in this organ. Casts of bigger collecting vessels, lymph trunks, and thoracic duct can be obtained by …

The Study Of Biominerals By High Resolution Transmission Electron Microscopy, Stephen Mann

Scanning Electron Microscopy

This paper presents an overview of the study of the ultrastructure of biogenic inorganic solids (biominerals) using high resolution transmission electron microscopy (HRTEM). A range of biominerals have been studied including iron oxides, calcium phosphates, calcium carbonates and silica. The studies have revealed information concerning the structural complexity of these materials and have identified crystallographic order and disorder at the nanometre level. In addition, the results have aided the elucidation of the mechanisms of nucleation and growth of biogenic minerals.

Purification Of Anthrax Toxin Protective Antigen Component And Characterization Of Its Binding Interaction With Bovine Kidney Cells, Daniel Dalton Martin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protective antigen component of B. anthracis toxin was produced and purified to the >99% level. Toxin was purified from culture supernatant utilizing concentration and liquid chromatography techniques. Purity was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

The purified protective antigen retained biological and antigenic activity as evidenced respectively by lethality in Fischer 344 rats when injected in combination with lethal factor, and by positive results on the Ouchterlony double diffussion assay.

Radioiodinated protective antigen was used both in the in vivo and the in vitro experiments.

In vivo distribution of labelled protective antigen was determined in Fischer 344 rats. Assay …

Detection Of Abnormal Milk With Impedance Microbiology Instrumentation, Fahad Ali Abdulghany Khayat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mastitic milk was detected by obtaining conductance measurements using an impedance microbiology Bactometer® 120 SC instruments. Conductance readings taken after 30 min at 25'C separated normal and abnormal milks when readings differed by more than 3% from the variance among instrument module wells. Samples blended from four quarters of a cow indicated milk from one quarter was abnormal if the salt level in the abnormal quarter raised the blend conductivity above that of normal samples and variance among the wells. Either solid or liquid substrates that contained bacterial stimulants could be used to accelerate bacterial acid production or to reduce …

Hormonal Control Of Phloem Loading In Celery (Apium Graveolens L.), Mark Watts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous research has indicated that phloem loading may be regulated by plant growth regulators. This conclusion, however, is based on circumstantial evidence in that previous experiments implemented complex tissue such as leaf discs or petioles to simulate phloem loading. Celery is a favorable system to measure phloem loading because it utilizes pure vascular tissue and/or isolated phloem tissue. Pure phloem tissue has not been used to date in phloem loading research.

It was demonstrated that the plant growth regulators gibberellic acid (GA₃) and indole acetic acid (IAA) caused an enhancement of sucrose-loading in vascular bundles and in isolated …

Viruses In Water, Nasrin Mohammadpour Daryaee

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The use of water by man, plants and animals is universal. Without it there can be no life. Every living thing requires water. Man can live nearly two months without food, but can live only three or four days without water. In our homes, whether in the city or in the country, water is essential for cleanliness and health. Water can be considered as the principal raw material and the lowest cost raw material from which most of our farm produce is made. It is essential for the growth of crops and animals and is a very important factor in …

The Determination Of Wet Weight Concentrations Of Elements In Freeze-Dried Cryosections From Biological Cells, Karl Zierold

Scanning Electron Microscopy

Energy dispersive X-ray microanalysis in STEM (scanning transmission electron microscope) of freeze-dried cryosections from biological cells provides information on the subcellular element distribution in terms of dry weight concentration. The local dry weight content in the range of 5-50%, respectively the local water content within 50 to 95%, in different subcellular compartments can be determined by measuring the darkfield intensity by means of an annular detector in STEM. Calibration is done by measuring the darkfield intensity of similarly prepared cryosections from dextran-water-solutions in varying concentration. Thus, by combining the X-ray microanalytical data evaluated by the continuum method with the STEM …

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 …

Technical Parameters Of Plastics (Mercox Cl-2b And Various Methylmethacrylates) Used In Scanning Electron Microscopy Of Vascular Corrosion Casts, T. Weiger, A. Lametschwandtner, P. Stockmayer

Scanning Electron Microscopy

The most frequently used resins for vascular corrosion casting Mercox Cl-2B, Mercox Cl-2B diluted with methylmethacrylate (MMA) monomer and various self prepared MMA and hydroxyproyl-methacrylate mixtures were tested with regard to their thermostability, shrinkage, viscosity and replication quality. It was found that tempering of the plastics improves their thermostability with the exception of Mercox Cl-2B and that shrinkage depends on the amount of monomers a resin contains. In detail; Mercox Cl-2B has the lowest shrinkage (8.018%) whereas a hydroxypropyl-methacrylate mixture possessed the highest (20.408%). But, on the other hand, viscosity decreases with the quantity of monomers. All resins tested were …

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 …