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Lenses suffering from "typical senile cataract" prepared by "critical point drying"and by sprinkling with gold, were examined under the scanning electron microscope. The images thus obtained gave a three-dimensional representation of structural changes within the lens determined in histological investigations performed with the light microscope.
A tooth and associated periodontal tissues from a patient with the diagnosis of periodontosis was subjected to scanning electron microscopic evaluation after reflection of the soft tissue portion of the lingual defect. The cemental surface of the apical portion of the lesion was found to be populated by markedly similar rod-shaped organisms. The microorganisms were observed to be continuously present in a coronal-apical direction as the transition from cementum to the attached soft tissues at the base of the defect were examined. These findings provide additional evidence that the lesion of periodontosis is characterized by a rather distinct microbial population of rod-shaped organisms located predominately at the base of the defect.
The innervation within the organ of Corti of guinea pigs, chinchillas and rabbits was studied in the scanning electron microscope. Specimens were fixed, dissected, critical point dried and coated with gold. Final dissection of the specimens was done in the dry state in the planes of the former fluid spaces. The courses of the efferent and afferent nerve fibres are described. The efferent fibres reach the outer hair cells by crossing the tunnel space, run between the outer pillars and divide several times in the space of Nuel. The afferent fibres cross the floor of the tunnel and turn basalwards in the outer spiral bundles where they run for at least 0.5-0.8 mm before connecting with the outer hair cells. Small nerve endings on every fifth to tenth outer hair cell disappear after cutting the efferent nerves, thus indicating their efferent nature.
Three-dimensional structures of human vestibular sensory epithelia were studied under scanning electron microscope. The saccular macula showed an "L" pattern and increased in thickness near the striola. The utricular macula appeared like an open shell. Flask and test-tube shaped hair cells were identified as type-I and type-II sensory cells respectively. Stereocilia were arranged in a step like progression; the kinocilium was near the longest stereocilium and looked more flexible than stereocilia. The tallest stereocilia and kinocilia faced away from the striola toward the periphery in the macula sacculi, and toward each other along the striola in the utricular maculae. Polarization directed to the utricle in the lateral crista, and away from the utricle in the anterior and posterior cristae. Otoconia varied in size and shaped like crystals with pyramidal ends.
This comparative investigation was carried out to evaluate the remineralization potential on early artificial carious lesions under Scanning Electron Microscope (SEM) of a Mineral enriched mouthrinse and a fluoridated dentifrice using an in-vivo intra-oral removable appliance model. This findings revealed that the remineralization was found to have occurred in almost all the samples (in children) using non-fluoridated, fluoridated dentifrices as well as those using mineral enriched mouthrinse. However the qualitative analysis of the remineralization revealed that in case of non-fluoridated dentifrice group, the prismatic holes showed deposition of granular, variable sized particles with uneven distribution, while in fluoridated dentifrice group, deposits were found to have partially but more densely filled up the prism cores. In case of mineral enriched mouthrinse group these deposits were found to be in the form of amorphous globular precipitate.
Dispersed monolayer cultures of post-natal mouse cerebella were studied using scanning electron microscopy. Special attention was given to the morphology of the brain macrophages and their interaction with neuronal cells. The brain macrophages resemble other macrophages and mononuclear phagocytes in vitro, reported in the literature. Their ability to induce neuronal growth cones to avoid contact, results in areas devoid of neuronal processes (halos) in this culture system; this seems of considerable interest in connection with their possible developmental role in post-natal reshaping of the brain. Scanning electron microscope observations indicate that these halos are not the result of phagolysis of already established neuronal networks, but can only be induced during neuronal growth and process formation. Established, intact neurons are apparently not altered or harmed by contact with brain macrophages.
The possible clinical usefulness of scanning electron microscopic observation of urinary cytologic specimens has been suggested for selected patient populations. To begin to determine the specificity and sensitivity of the procedure, cytologic specimens (48 catheterized urine and 49 bladder washings) from 85 patients with bladder tumor or nonmalignant urologic diseases were observed by scanning electron microscopy (SEM) and compared with observations by light microscopy. This study provides evidence that SEM exfoliative cytology in catheterized urine and/or bladder washings has considerable specificity for low-grade, low-stage bladder tumors, but may not be sufficiently sensitive for use in routine urologic practice. However, this procedure may be of use in following patients with previously resected low-grade, low-stage bladder tumors for the early detection of recurrences.
The possible changes in the subarachnoid space after subarachnoid haemorrhage were studied in animals by using a scanning electron microscope (SEM). About 1 ml/kg of autogenous blood was injected intracisternally in 36 adult mongrel dogs to investigate changes in the subarachnoid space, over periods ranging from immediately after the injection to as long as 6 months. We have come to the conclusion that the injected blood disappears in about one to two weeks; the fibrosis or thickening of the arachnoid membrane appears in one to three weeks, and then returns to normal in a month in instances of rapid recovery, but there are some cases in which fibrosis persists for a long period and becomes chronic. The fact that an increase of fibrous tissue was found in the parietal region, where the injected blood had hardly reached, appears to indicate that the fibrosis is not always limited to the site of the haemorrhage but can occur in remote regions. We also discuss the usefulness of the SEM in the observation of the subarachnoid space, and the finding that vascular specimen preparations can be made by perfusing the brain with 2-10% phosphate-buffered formaldehyde solution.
PURPOSE: To study with the scanning electron microscope the interfacial phenomenon that occurred in the presence of excessive surface moisture following the application of an acetone-based adhesive to acid-conditioned dentin. MATERIALS AND METHODS: Specimens consisted of flat dentin discs that were divided into three groups based upon the status of remaining surface moisture: (1) 3-second dry group, (2) blot-dry group, with the conditioned dentin surface remaining shiny as opposed to matte, and (3) overwet group: an additional 40 mL of distilled water spread thin on the dentin surface after blot-drying. Polished resin-dentin interfaces were brought into relief using plasma-etching and examined without further embedding. RESULTS: Although a hybrid layer was observed in all three groups, there was (1) a sequential deterioration of the bonded assembly along the hybrid layer-resin interface, and (2) loss of complete tubular seal as the quantity of surface moisture increased. Intratubular resin globules were observed beneath short resin plugs in the 3-second dry group. Small, isolated blister-like spaces, trapped within the resin layer, were observed along the surface of the hybrid layer in the blot-dry group, while similar, but larger spaces were found in the overwet group. The blister-like spaces, which were often continuous with incompletely sealed tubular orifices, were partially filled with extraneous resin globules dispersed within an amorphous matrix.
Alterations in the respiratory epithelium of gills of a catfish, Heteropneustes fossilis by the sublethal and lethal concentrations of HgCl2 have been observed using scanning electron microscope. Fish exposed to 0.1 ppm shows a thin coat of mucus, but the continuous layer of mucus is not retained in 0.3 ppm after 24 h of exposure. Epithelial cells of the gill filament are hyperplastic. Other changes in the respiratory epithelium are contraction of epithelium, formation of interlamellar bridge and diminishing number of microridges. Massive destruction of the respiratory epithelium by deep lesions and sloughing of epithelial layer in 0.5 and 1.0 ppm solutions after 6-12 h of exposure apparently causes death to the fish. SEM observations are well in conformity with the findings made at light microscopic level.
Amelogenesis imperfecta (AI) is a hereditary defect in enamel formation affecting both primary and permanent dentition. Scanning electron microscopic investigation is one of the most effective methods in diagnosing and identifying the type of amelogenesis imperfecta. The aim of this study was to investigate the ultrastructure of different types of amelogenesis imperfecta enamel. The primary teeth of three children with AI aged 4, 10 and 11-years-old were studied by scanning electron microscopy and irregular enamel, irregularities in enamel crystallites, hypoplastic areas on the enamel surface were seen. Histopathological evaluation revealed predentin areas with irregular canaliculi between normal dentin and internal resorption areas in the pulp tissue. Conclusively, in amelogenesis imperfecta, enamel tissue is mostly affected besides minor defects in dentinal and pulpal tissue.
Microscopic features on scanning electron micrographs of epoxy-replicas of the second molars of nine wild-caught adult female Japanese monkeys, Macaca fuscata, from Oita Takasakiyama, Kyushu, were measured using a digitizer. These monkeys had been fed a monkey-diet during three or four days of captivity before replicas were made. Six of these specimens showed such heavily worn second molars that narrow peripheral enamel bands surrounded large dentin exposures and the cusps of the others had been worn off. Microwear measurements from sites near facet 9 were compared with those of facet 9 of three kinds of hard-object feeding primates from the literature. The mean percentage of pits among all features (pits and scratches) in these samples was almost equal to those that have been reported previously for Pongo pygmaeus and Cebus apella, but tended to be smaller than those of Cercocebus albigena. The mean pit width of these specimens was larger than that of Pongo pygmaeus and was almost equal to those of Cercocebus albigena and Cebus apella. The mean scratch width of these samples was larger than those of Cebus apella and Pongo pygmaeus. These features and the significant differences between these samples and the nonhard-object eaters such as Colobus guereza place these Macaca samples in the category of hard-object feeders. Additional directly observed seasonal feeding behaviors that would confirm the dietary contribution to these features is now needed.
Adult stored product beetle mandibles were used as a subject for this scanning electron microscopic study. A total of 34 species are represented. Discussion is organized taxonomically by family, and comparisons are made between species where possible. Established terminology for morphological processes has been applied to all characteristics of mandibles reported in earlier literature; however, several new terms have been added in an attempt to better describe specific attributes of a species.
A procedure has been developed for scanning electron microscopy that enables the visualization of kinetochores along the surface of isolated chromosomes of the Indian muntjac. Indirect immunofluorescence and thin section analysis of the kinetochores of those isolated chromosomes verified that these structures retained in vivo composition and morphology during the isolation procedure. In scanning electron micrographs the outer surface of the outer kinetochore plate can be visualized as a series of fibers 25-30 mn in diameter that are arranged across the plate. These images are comparable to those obtained by whole mount transmission electron microscopic procedures (Rattner 1986) and are compatible with a model of the kinetochore in which chromatin fiber from the body of the chromosome extend to the outer kinetochore plate.
A technique has been developed by which mating gametes of Chlamydomonas eugametos can be studied in the Scanning Electron Microscope. A detailed description of the mating process, from the initial flagellar agglutination until the release of free vis-à-vis pairs, is presented. Flagella appear to agglutinate at random points on their surface. This is followed by a rapid increase of the contact area such that they "line-up" tip to tip. Flagella always exhibit a typical position prior to cell fusion. After cell fusion the flagella of a pair separate rapidly while the female have shortened about 33%. In a vis-à-vis pair the plasma bridge has contracted. The observations are interpreted in terms of a specific reorganization of the sexuale aggregate.
A new image contrast is reported for LSIs covered with an insulator film in a low accelerating voltage scanning electron microscope. The surface region above the conducting lines is often observed brighter than that without conducting lines. This contrast is quasi-stationarily observed contrary to well-known capacitive-coupled voltage contrast, and is called static capacitance contrast. The optimum irradiation conditions for the maximum image contrast is studied and its mechanism is discussed.
In this study, D. filaria causing parasitic bronchopneumonia in sheep was observed using a scanning electron microscope. This parasite belongs to the Trichostrongyloidea super family. The oral opening of D. filaria was observed to be small and circular in shape. Lips were not evident. Any difference between anterior ends of male and female parasites was not observed in present study. In the female parasite, the anus was seen as a fissure in shape. The post anal papilla was seen near the posterior end of the female. Spicula and cloacae of male parasites were observed.
Silicone negative replicas of dentine islands exposed by occlusal attrition were examined on extracted human teeth using the scanning electron microscope. Because the details of the dentinal tubules were reproducible on the silicone impression, the replication technique was applied in vivo to occlusal attrition to demonstrate patent dentinal tubules in cases with symptomatic exposed dentine islands. using this replication technique, it should be possible to monitor the effect of the therapeutic management of symptomatic tooth attrition on dentinal tubule closure.