Biology Commons^™

'Spot The Difference': Finding Small Differences Between Closely Similar Images, A. A. Mills

Scanning Microscopy

Small differences between two complex and closely-similar photographs may be located by viewing the uniformly illuminated pair with a stereoscope. Provided the observer possesses normal stereoscopic vision, any non-common elements will appear to stand above the general picture plane provided by the fused common background. It is emphasised that the images being examined are not a conventional stereo-pair, although the left- or right-eye member of such a pair may be so compared with its counterpart in a subsequent stereopair. This stereoscopic technique was found preferable to the alternative 'blink' method for most scanning microscope images, although it is advantageous to …

Architecture Of The Medial Smooth Muscle Of The Arterial Vessels In The Normal Human Brain: A Scanning Electron-Microscopic Study, Toshitaka Shiraishi, Saburo Sakaki, Yasuo Uehara

Scanning Microscopy

The architecture of the medial smooth muscle of arterial vessels in normal human brains was investigated using scanning electron microscopy. We could divide the arterial vessels into four subdivisions according to the number of the circular muscle cells. The arteries ( > 100 μm in diameter) had 4-20 layers of circular smooth muscle cells; individual circular muscle cells were spindle-shaped and occasionally had branches at their ends. Multidirectional muscle cells were observed in the medio-adventitial border only at the branching sites in large arteries (>300 μm), but at both branching and non-branching sites in the small arteries (100-300 μm). The …

Analyses Of Dental Pulp In Restored Teeth, D. L. Lentz, J. T. Buchanan, D. R. Basinger

Scanning Microscopy

Restored teeth were extracted from test animals at four time intervals (1 hour, 1 day, 1 week, and 3 months) following amalgam insertion. Extracted teeth were frozen in liquid nitrogen, cryo-fractured so as to expose the pulps and then freeze-dried. Pulps were analyzed for mercury content by energy dispersive spectrometry (EDS) and atomic absorption spectrophotometry (AAS). Mercury levels appeared below the detection limits of EDS but could be detected by AAS which showed the highest readings seven days after amalgam insertion.

The Response Phase - The First Six Hours After Acute Airway Injury By So2 Inhalation: An In Vivo And In Vitro Study, W. C. Hulbert, S. F. P. Man, M. K. Rosychuk, G. Braybrook, J. G. Mehta

Scanning Microscopy

We have identified an airway epithelial response following acute injury that cannot be termed 'repair' or regeneration. It precedes these well characterized events and it is termed the 'response phase'. We tested the hypothesis that for the first 6 h following acute injury to the tracheal mucosa, the initial cellular events of the response phase will continue as in vivo even if the tissue is maintained in vitro in an Ussing chamber. The tracheal mucosa of anesthetized, intubated mongrel dogs was injured by the inhalation of SO₂ 500 ppm for 1 h (7 dogs); controls (3 dogs) breathed filtered, …

X-Ray Microanalysis Of Calcium Containing Organelles In Resin Embedded Tissue, G. Nicaise, I. Gillot, A. K. Julliard, E. Keicher, S. Blaineau, J. Amsellem, J. C. Meyran, M. L. Hernandez-Nicaise, B. Ciapa, C. Gleyzal

Scanning Microscopy

The localization of calcium in cell organelles at the electron microscope level is often achieved through cytochemical techniques, and verified by X-ray microanalysis. Various methods have been used to cytochemically detect calcium or calcium-binding sites : calcium loading, calcium substitution by strontium, barium, or even lead, and calcium precipitation by oxalate, phosphate, fluoride, or pyroantimonate. Their results may have heuristic value, particularly in preliminary studies of poorly known cell types. A complementary and more physiological approach is offered by quantitative measurement of the total calcium content of organelles after cryofixation.

Resin embedding is less demanding than cryomicrotomy and gives better …

Design And Applications Of In-Situ Differential Scanning Electron Microscopy, A. Sicignano, M. Vaez Iravani

Scanning Microscopy

Contrast enhancement in the scanning electron microscope (SEM) is usually achieved by either of the two techniques of black level suppression, and differential imaging. This paper is mainly concerned with the latter method. Differential imaging of SEM images is commonly accomplished by either using a selective electronic filtering circuit (time sensitive) on the video signals, or the post processing of a collected digitized image (application of special kernel operatives). A technique is described that is capable of generating true in-situ SEM differential video signals of local sample features. Characteristics of this method are enhanced sample feature-boundary sensitivity, suppression of large …

Mechanism Of Hydrolysis Of Octacalcium Phosphate, B. B. Tomazic, M. S. Tung, T. M. Gregory, W. E. Brown

Scanning Microscopy

The chemical and structural properties of hydrolyzed octacalcium phosphate (OCP) appear to be of high relevance to tooth, bone and pathological bioapatites. Hydrolysis of synthetic well-crystallized OCP was studied at constant pH by using the pH stat method over the 6.1 to 8.6 range at 50°C and to a lesser extent at 37°C. Hydrolytic transformation proceeds according to thermodynamic requirements except for some retardation at the highest pH value as a consequence of decreased solubility of OCP which may be rate determining. The product of hydrolysis, OCP-hydrolyzate (OCPH), was characterized by chemical analysis, scanning electron microscopy, x-ray diffraction, electron microprobe …

Sodium Lauryl Sulfate Enhances Nickel Penetration Through Guinea-Pig Skin. Studies With Energy Dispersive X-Ray Microanalysis, Magnus Lindberg, Samuel Sagström, Godfried M. Roomans, Bo Forslind

Scanning Microscopy

The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis ( EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na. Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX …

Scanning Electron Microscope And X-Ray Diffraction Investigations Of Mudrock Fabrics, Textures And Mineralogy, J. M. Huggett

Scanning Microscopy

Mudstones from a broad range of depositional environments have been investigated to determine whether fabric, texture or mineralogy may (1) be used to identify the environment of deposition and (2) be correlated with poroperm. The diversity of fabrics and textures reflects features of the detrital mudstone composition, compaction and diagenesis, rather than environment of deposition. Preferred orientation has been disturbed by bioturbation and growth of post-compactional authigenic minerals; these factors have reduced to nil any correlation which may have existed between fabric, measured as the illite orientation ratio (O/R) and environment of deposition.

It is mineralogy rather than fabric or …

Preparation Of Dipteran Larvae For Scanning Electron Microscopy With Special Reference To Myiasigen Dipteran Species, I. Ruiz-Martinez, M. D. Soler-Cruz, R. Benitez-Rodriguez, M. Diaz Lopez, J. M. Perez-Jimenez

Scanning Microscopy

Although controversy exists concerning the role of chemical fixatives in scanning electron microscopy (SEM) studies of Dipteran larvae, we have observed that filtered 10% formaldehyde solution gives excellent results as a preservative. After immersing in vivo in formaldehyde, the larvae material is preserved for prolonged periods (up to 8 months), before examination with SEM. As a fixative, formaldehyde preserves the structure of the larval cuticle and produces no visible artifacts. Moreover, postfixation is not necessary.

Due to pecularities of the way of life of Wohlfahrtia magnifica (principally the accumulations of necrotic tissue, purulent particles, and other types of substances that …

The Vascular System Of Xenotransplanted Tumors -Scanning Electron And Light Microscopic Studies-, M. A. Konerding, F. Steinberg, V. Budach

Scanning Microscopy

A widely used model for investigating basic tumor characteristics and different treatment modalities preclinically is the immune-deficient, athymic nude mouse. This model offers many morphological parallelisms to the clinical situation.

The aim of this study is to demonstrate the vascularization pattern of xenotransplanted human melanomas and sarcomas using different methods. Xenotransplanted tumors of 62 congenital thymusaplastic nude mice were examined ultrastructurally and topographically after corrosion cast and tissue preparation. Quantitative measurements of tumors injected with India ink were carried out to obtain comparable information on the vascular densities in the tumors.

Quantitative measurements showed that there is no zonal, topographic …

Altered Fungal Morphogenesis During Early Stages Of Ectomycorrhiza Formation In Eucalyptus Pilularis, P. F. Jacobs, R. L. Peterson, H. B. Massicotte

Scanning Microscopy

Scanning electron microscopy (SEM) of Eucalyptus pilularis roots inoculated with Pisolithus tinctorius, under controlled conditions, revealed altered morphogenesis of fungal hyphae in contact with the root surface. These changes occurred prior to the formation of a full fungal mantle and resulted in the formation of a compact fungal layer as a consequence of fusion of proliferating, branching hyphae. Although similar growth patterns have been observed in the inner mantle of fully developed ectomycorrhizae using contrast interference microscopy, this is the first time this feature has been observed during early mantle formation using SEM. Changes in fungal morphology during early …

Quantitative Microanalysis Of Nitrogen Distribution In Carpospores Of Gracilaria Secundata With Scanning Auger Microscopy, Åke Lignell, Rein Kalm, Godfried M. Roomans, Angelica Von Hofsten, Olof Vingsbo

Scanning Microscopy

Quantitative microanalysis has been performed with a JAMP 10 Scanning Auger Microscope at 0.5 μm spot size, on carpospores of Gracilaria secundata Harv.. Samples were fixed in glutaraldehyde and osmium tetroxide and embedded in plastic material. Thin sections were placed on solid copper discs. the surfaces of which had been smoothed by electropolishing.

Quantification of the nitrogen content was performed using a standard with known content of nitrogen.

Nitrogen was localized in the nucleus, chloroplasts and osmiophilic inclusions of the carpospore. Trace amounts of nitrogen were also found in cell walls, starch grains and in the embedding material.

The use …

Ultrastructural Variation In Enamel Of Australian Marsupials, C. F. Gilkeson, K. S. Lester

Scanning Microscopy

This paper initiates a survey of the enamel of fossil and extant Australian marsupials by scanning electron microscopy. Enamel was examined from 17 extant and 11 extinct marsupials. Assessment was made of prism packing pattern, prism course, tubule presence, tubule size and distribution. Values calculated were: prism diameter; prism axis ratio; cross-sectional prism area; cross-sectional ameloblast area; and numerical prism density.

Three different prism packing arrangements were found for extant and fossil marsupials within the classical Pattern 2. The Pattern 1 arrangement found in three extant species was relatively unexpected given the general acceptance of Marsupialia as having Pattern 2 …

Surface Studies Of Calcium Oxalate Dihydrate Single Crystals During Dissolution In The Presence Of Stone-Formers' Urine, M. Akbarieh, R. Tawashi

Scanning Microscopy

Dissolution of calcium oxalate dihydrate (COD) single crystals was studied at different pH levels and in different dilutions of stone formers' (SF) urine. The Fourier descriptors of the contour were determined during dissolution of COD using a quantitative morphological technique. The surface ruggedness of COD single crystals was determined from fractal analysis. The results obtained were compared with COD single crystals behavior in different dilutions of normal urine previously reported. The shape parameters and surface geometry of the dissolving COD crystals were significantly different in normal and SF urine. The data suggest that the shape descriptors and fractal geometry is …

Dentin: A Dynamic Substrate - A Review, David H. Pashley

Scanning Microscopy

The structure of dentin is unusual in that the number and size of its tubules changes as one moves from the periphery toward the pulp chamber. Near the pulp, the tubules are very close together and the water con tent of this deep dentin is high. Near the enamel, the tubules are far apart, occupying less than 1% of the surface area. When enamel or dentin is cut, the surface becomes covered by an adherent layer of cutting debris called the smear layer. Its composition presumably reflects the composition of the underlying dentin. It is only about 1 μm thick …

Scanning Optical Microscopy Of Semiconductor Materials And Devices, C. J. R. Sheppard

Scanning Microscopy

In the scanning optical microscope a focused light spot is used to illuminate the object and some property monitored as the spot is scanned relative to the object to build up an image. By monitoring different properties it is thus possible to use the scanning optical microscope in a wide range of imaging modes, which can be used to give much information concerning the structure and properties of semiconductor materials and devices. In the optical-beam induced current method the focused light spot generates electronic carriers in a semiconductor specimen, and the resultant current monitored. The technique can be used to …

Vascular "Sphincter" And Microangioarchitecture In The Central Nervous System: Constriction Of Intraparenchymal Blood Vessels Following A Treatment Of Vasoconstrictive Neurotransmitter, K. Nakai, Y. Naka, H. Yokote, T. Ikatura, H. Imai, N. Komai, T. Maeda

Scanning Microscopy

The site of action of neuropeptide Y (NPY), a potent vasoconstrictive neurotransmitter, on the intraparenchymal blood vessels in the rat parietal cortex was demonstrated using a corrosion cast technique with scanning electron microscopy. Our observations were confined to the cortical area where the regional cerebral blood flow (rCBF) had been reduced significantly by in situ application of NPY. A striking finding in that area was the diffuse narrowing of the perforating arteries in the upper cortical layers. Ring-like compressions on the corrosion casts, presumably formed by active vascular sphincters along the arteries, capillaries and venules within the brain parenchyma, seemed …

Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell

Scanning Microscopy

Low volume fungicide smoke particle deposits were studied with scanning electron microscopy and energy dispersive X-ray analysis. Under greenhouse conditions, particles deposited on Rhododendron leaf surfaces and onto inert, carbon planchets adjacent to Rhododendron leaves were characterized by electron beam analysis. Angular particles containing chlorine, identified as vinclozolin deposition, were quantified on a per unit area basis. Leaf samples collected from plants immediately adjacent to the smoke applicator had more particles than leaf samples collected elsewhere. More deposition was measured on leaf surfaces than on inert planchet surfaces. This study increased our knowledge about the effectiveness of using less fungicide …

The Use Of Scanning Electron Microscopy For Investigations Into The Three Dimensional Organisation Of The Interphase Nucleus, T. D. Allen, P. M. O'Connor

Scanning Microscopy

In an attempt to elucidate three dimensional information on the organisation of the nucleus, nuclei have been extracted from ascites tumour cells or tissue culture cells by a variety of biochemical techniques, and prepared for high resolution scanning electron microscopy using an osmium-thiocarbo-hydrazide infiltration procedure which has previously proved successful for analysis of chromosome structure. Nuclei were prefixed with either Methanol-Acetic acid, glutaraldehyde or formaldehyde and then extracted by a variety of detergents with the aim of a 'biochemical dissection' of their outer elements to allow surface visualisation of the nuclear lamina. Continued extraction removed all aspects of the nuclear …

Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua

Scanning Microscopy

Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to …

Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate

Scanning Microscopy

18 nm colloidal gold-antitubulin and 4 nm colloidal gold-antitubulin were used to label microtubules in adherent, fully spread platelets. Both sizes of marker effectively labelled microtubules in the partially extracted platelets. However only the 4 nm gold penetrated the dense microfilament matrix of the inner filamentous zone so that portions of microtubules within this cytoskeletal zone could be tracked. The gold marker could be visualized well with 1 MeV high voltage transmission EM and with 5 kV or greater secondary imaging or 20 kV backscattered imaging of carbon only coated samples. 1 kV secondary imaging permitted high resolution imaging of …

Effect Of Conidia Germination On Infection Of Brown Planthopper (Bph) By Insect Fungi, M. C. Rombach, R. M. Aguda, Donald W. Roberts

Biology Faculty Publications

Conidia of insect fungi actively invade BPH [brown planthopper]. After a conidium lands on the insect cuticle, germination takes about 8 to 16 h, depending on the temperature and relative humidity. After the germination, tuber is formed, the conidium produces specific chitinase enzymes to dissolve the insect cuticle. This allows the fungus to enter the insect body cavity, where further fungus growth occurs. At the end of the infection cycle, the mycelium sporulates on the outside of the insect. Conidia produced on the cadaver can infect healthy BPH initiating epizootics of the fungus. To test infection, 50 adult alate BPH …

Quantitative Margin Analysis In The Scanning Electron Microscope., J. F. Roulet, T. Reich, U. Blunck, M. Noack

Scanning Microscopy

Interface between restorative materials and tooth hard substances must be morphologically as perfect as possible to avoid plaque accumulation and subsequent secondary caries or pulpal diseases. Therefore the marginal behavior of restorations is an important parameter to predict their longevity.

Morphologically, the quality of margins is characterized by different well defined criteria. Using a replica technique it is possible to assess the complete marginal circumference of restorations in the SEM. Margins of restorations show a large variety of their morphology. This publication describes a method to quantify the quality of dental restorations.

The restoration margins are traced on the SEM …

Stimulation Of Collagen Formation In The Intestinal Anastomosis By Low Dose He-Ne Laser, David T. Yew, Winnie W. Y. Li, K. M. Pang, Y. C. Mok, C. Au

Scanning Microscopy

The effect of low dose He-Ne laser on the healing of intestinal anastomosis was studied in the albino rat. A small piece of jejunum was removed from each rat and the ends sutured back with a simple interrupted pattern. In the experimental animal, the anastomosis was Irradiated through an optic fiber with a He-Ne laser (1 mW) for 15 minutes whereas in the control animal, the anastomosis was not irradiated. The differences between the two groups were compared by histology, transmission electron microscopy, scanning electron microscopy and autoradiography 3 and 7 days after operation. The laser treated experimental animals demonstrated …

Complementary Surface Characterization Of Chalcopyrite By Electron Microscopy, Electron Spectroscopy, And Optical Reflectance, P. H. Ruzakowski, P. H. Holloway, G. Remond

Scanning Microscopy

Surface oxidation of polished natural specimens of chalcopyrite (CuFeS₂) at temperature between 23°C and 300°C in air has been characterized by Auger electron and X-ray photoelectron spectroscopies. The reaction products consisted of an outer iron oxide layer and an intermediate copper rich sulfide layer. Several different oxides and sulfides were consistent with the electron spectroscopy data, so specimens were analyzed as a function of time and temperature at selected 20 μm diameter areas with an optical microreflectometer (OMR). Since the optical properties of a compound are unique, a reflectance model with three homogeneous layers was used to calculate …

Optical Design Considerations In Confocal Scanning Microscopy, T. Wilson

Scanning Microscopy

We review the properties and applications of confocal optical systems. We concentrate on non-fluorescent reflection systems and on applications which make use of the unique optical sectioning property of these instruments to provide three-dimensional images. A crucial design choice concerns the form and size of the detector. We therefore concentrate on the role of the detector size on the strength of the optical sectioning. We find that although the sectioning becomes weaker as the detector sizes where the sectioning remains essentially constant. We also consider the role of lens aberrations which are inevitably present and find, inter alia, that these …

A New Versatile Holder For The Calibrating Standard Used For Quantitative Analysis In Jeol 840 Sem, Michael Dvorachek

Scanning Microscopy

An improved holder has been designed for a cobalt calibrating standard used in an EDS Link 10,000 system attached to a JEOL 840 SEM. This holder allows the calibration of the EDS software for a wide range of samples differing in size, surface and height. These differences usually cause difficulties during quantitative analyses. The new holder allows the position of the cobalt to be adjusted according to the size and height of the sample.

Ultrastructural And Functional Effects Of Lipopolysaccharide And Interleukin-2 On Human Nk Cells, Yuan-Hsu Kang, Mitchell Carl, Lorrita P. Watson

Scanning Microscopy

Bacterial endotoxin (lipopolysaccharide, LPS) and interleukin-2 (IL-2) are known to stimulate NK cell mediated cytotoxicity against tumor cells. In the present report we sought to correlate the stimulatory effect of LPS and IL-2 on NK cell activity with ultrastructural changes which occurred as a result of such stimulation. Peripheral blood mononuclear cells (PBMC) were purified from healthy donors by a Ficoll-Hypaque density gradient technique. Leu-11a⁺ NK cells were isolated by flow microfluorometry using a monoclonal FITC conjugated anti-Leu-11a antibody and a FACS II cell sorter. The PBMC were incubated, respectively, with E. coli LPS or recombinant IL-2 (IL-2) for …

Crystal Associated Diseases: Role Of Scanning Electron Microscopy In Diagnosis, K. P. H. Pritzker, P. -T. Cheng, M. D. Grynpas, D. P. Holmyard

Scanning Microscopy

As crystals are important etiologic agents for disease, their accurate identification in tissues and body fluids is of utmost importance. This paper surveys the roles of crystals in disease process and outlines current analytical techniques for crystal detection and identification in bone tissues. The value of multiple correlated techniques is demonstrated including scanning electron microscopy, x-ray energy spectroscopy and powder diffraction analysis. The current feasibility of utilizing intermediate voltage scanning transmission analytical electron microscopy to integrate these analytical techniques on the same tissue sample is emphasized.