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PubMed2006

Characterization of acrylic polyamide plastic embolization particles in vitro and in human tissue sections by light microscopy, infrared microspectroscopy and scanning electron microscopy with energy dispersive X-ray analysis.

Vascular embolization is a well-established practice for the treatment of tumors and vascular lesions. Rounded beads (microspheres) of various materials (collagen, dextran and trisacryl-polymer-gelatin) were developed to solve problems encountered with earlier versions of embolic material. We performed histochemistry, Fourier transform infrared microspectroscopy and scanning electron microscopy with energy dispersive X-ray analysis on two uterine and one hepatic specimen with unidentified intravascular foreign material, and examined a reference embolization product for comparison. The hematoxylin and eosin stained tissue sections showed multiple foci with unidentified intravascular foreign material and fibrous obliteration of vessel lumens. Only one case had a clinical history of previous embolization but without specifying the material used. One case was submitted for identification of a 'parasite'. The material stained positively with Sirius red and mucicarmine, variably with Masson's trichrome stain and Movat pentachrome, and did not stain centrally with periodic acid Schiff with diastase. Infrared spectrophotometric analysis of the material from all three cases demonstrated the spectrum of acrylic polyamide plastic. A control sample of EmboGold exhibited infrared microspectroscopic spectra similar to the three tissue specimens. Analysis by scanning electron microscopy with energy dispersive X-ray analysis demonstrated some differences in elemental composition between the tissue sections and the selected reference material. To our knowledge, this is the first report of infrared spectrophotometric analysis with scanning electron microscopy with energy dispersive X-ray analysis of an acrylic polyamide plastic embolization product both in vitro and in human histologic tissue sections. In cases lacking appropriate clinical information, identification by these methods and/or a panel of special stains may assist pathologists unfamiliar with this material's light microscopic appearance.

Acrylic Resins↗

PubMed1997

Light and scanning electron microscopy of rabbit lens capsules with intraocular lenses.

PURPOSE: To examine postoperative changes in the lens capsules of rabbit eyes after phacoemulsification and aspiration of the crystalline lens and implantation of posterior chamber intraocular lenses (IOLs) using light and scanning electron microscopy. SETTING: Research Laboratory, Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: The crystalline lens was emulsified and aspirated and an IOL implanted in the capsular bag or ciliary sulcus of each eye in adult albino rabbits under general anesthesia. Animals were killed after 4 weeks, and the lens capsules were removed. The specimens were observed under phase-contrast microscopy and processed for light and scanning electron microscopy. RESULTS: Phase-contrast microscopy revealed presumed lens epithelial cells (LECs) on the central posterior capsules in association with regenerating lenticular fibers and Elschnig pearls in the peripheral capsules. Scanning electron microscopy showed the accumulation of fibrous extracellular matrix on the surface of the posterior capsule in eyes in which the IOL was implanted in the ciliary sulcus. Deposition of packed material attached to the surface of IOLs and of Soemmering's ring were observed in eyes with in-the-bag IOL fixation. At a higher magnification, a parallel arrangement of lenticular fibers was seen in the regenerated lens structure on posterior capsules. An identical structure was observed under light microscopy. Outgrowth of presumed LECs from residual anterior lens capsules and adhesion of macrophages and giant cells were observed on the IOL surface. CONCLUSION: Two types of postoperative changes were observed in lens capsules after implantation of IOLs: accumulation of fibrous extracellular matrix and newly formed lenticular fibers. These changes are attributed to the proliferation of LECs and can induce posterior capsule opacification after IOL implantation.

Animals↗

PubMed1976

Scanning electron microscopy of surface features of hamster embryo cells transformed in vitro by X-irradiation.

Scanning electron microscope studies were carried out on Syrian hamster embryo cells transformed in vitro by X-irradiation (300 rads) (X-ray transformed) and on normal nonirradiated and irradiated nontransformed controls. Transformed cells appeared in scanning electron microscopy as pleomorphic, thick cells piling up over each other and exhibiting extensive surface features consisting of microvilli, blebs, and ruffles. These surface structures were seen on single as well as on densely cultured transformed cells during both interphase and mitosis. The complex surface was observed shortly after transformation (on cells of a 20-day-old clone) and seems a permanent feature of the X-ray-transformed cells (present after 8 years in culture). All controls appeared by scanning electron microscopy as regular, flat, and smooth cells which grew in high-density cultures to seemingly contact-inhibited monolayers. During mitosis the normal cells (control, nontransformed) displayed surface excrescences similar to those of the transformed cells making the mitotic normal cells indistinguishable from transformed cells. The complex surface features in the normal cells were temporary and reversed back to characteristic smoothness upon reentrance into interphase.

Agglutination↗

PubMed1997

In vitro calcified tendon collagen: an atomic force and scanning electron microscopy investigation.

Atomic force microscopy (AFM), scanning electron microscopy and X-ray energy dispersive spectroscopy have been performed on decalcified turkey tendons submitted to in vitro calcification in order to investigate the morphology and the surface relationships between the inorganic phase and the collagen fibres during deposition and compare with those found for physiologically calcified samples. 'Tapping mode' AFM was used to reduce the vertical force applied to the samples, which were examined without any preparation. A further characterization has been carried out by means of X-ray diffraction, infrared absorption and chemical analyses. The observations indicate that the inorganic phase deposited on collagen fibres during in vitro calcification is poorly crystalline B carbonated apatite. The composition, structure and dimensions of apatitic crystallites, as well as their orientation with respect to collagen fibrils, are very similar to those characteristic of physiologically calcified tissues. However, the crystallites seem to be nucleated on the fibril surface, without appreciably affecting the molecular packing of collagen.

Animals↗

PubMed1990

An improved silver staining technique as an alternative nuclear or combined nuclear nerve-fiber impregnation for comparative light-, secondary and backscattered electron scanning microscopy.

Slices of rat brain were stained by a new silver impregnation technique. This method takes into consideration the pH-dependent differences of silver stain affinity of nerve tissues and can be used alternatively as a stain for nuclei or as a method for combined demonstration of nuclei nerves fibers. The slices were studied at the light microscopical (LM) level and subsequently with a scanning electron microscope, using secondary (SSEM = classical SEM), and backscattered electron detectors (BSEM). This new silver staining technique offers the opportunity of comparative studies with regard to different information acquired with LM, SSEM and BSEM. The described method allows to distinguish between nervous and glial tissue without necessarily damaging the glial tissue surrounding the nerve fibers. Specifically, scanning electron microscopy with backscattered electron detector of in situ preparations provides a higher contrast of stained and unstained tissue and increased depth of focus as compared to secondary electron detectors.

Animals↗

PubMed1986

[Pulmonary hydatidosis. Comparison of cytology and scanning electron microscopy].

The puncture of a hydatid cyst with a fine needle is not generally recommended as a procedure and may even be contra-indicated in the first instance. Sometimes, however, the cytologist will be surprised to discover some scolices in the aspirate when the radiology is misleading, or not suggestive, and the serology is negative. We report two cases where the diagnosis was made by the cytological examination of the aspirate. The cytological study of the liquids was compared with electron microscopy scanning, enabling the stages of development of the parasite in the tissue of the pulmonary parenchyma to be assessed.

Adolescent↗

PubMed2003

Imaging and non-contact profile analysis of Nd:YAG laser-irradiated teeth by scanning electron microscopy and confocal laser scanning microscopy.

Two types of non-contact optical profilometers, one performing scanning electron microscopy (SEM) installed with a 3D analyzer and another performing confocal laser scanning microscopy (CLSM) were applied to evaluate imaging and surface profiles simultaneously on enamel and dentin after Nd:YAG laser irradiation. The results were correlated with a stylus profilometer. Surface roughness (Ra) was also measured. Laser was applied perpendicularly to vertical sections of human extracted caries-free molars. Analysis was done on the same spot of the same specimen by both SEM and CLSM for comparison. After irradiation, enamel produced a flake-like surface and dentin resulted in a melted globule surface. SEM and CLSM gave similar surface profiles and different image contrast. The Ra obtained by CLSM was larger than that by SEM. Both SEM and CLSM provided a non-contact evaluation of tooth structural change by laser irradiation through surface analysis in selected micro areas, which was not possible using the stylus profilometer.

Dental Enamel↗

PubMedDate not supplied

Examination of human and animal leukemic cells by high contrast scanning electron microscopy.

Investigation of human or animal (sheep and ox) leukemic cells by scanning electron microscopy enabled the identification and study of some ultrastructural details of the cell surface. A more detailed visualization by the high contrast technique of the same cell surface was obtained, in this work, for the first time in the biological field. This technique allows a better interpretation of any zone of the preparation examined, irrespective of the species from which the cells are collected.

Animals↗

PubMed1996

In vitro destruction of nerve cell cultures by Acanthamoeba spp.: a transmission and scanning electron microscopy study.

Trophozoites of 4 species of Acanthamoeba were cytopathic for cultured rat B103 neuroblastoma cells. Cytopathogenicity was evaluated by a chromium release assay and by transmission and scanning electron microscopy. Acanthamoeba culbertsoni, Acanthamoeba castellanii, and Acanthamoeba polyphaga destroyed B103 target cells at 37 C as evidenced by the release of radiolabel. Acanthamoeba astronyxis did not produce cytopathology at 37 C but destroyed nerve cells at 25 C. Transmission and scanning electron microscopy of cocultures maintained at different time periods revealed that all species of Acanthamoeba exhibited long cylindrical structures, termed digipodia, which made contact with target cells. Following this effector cell-target cell contact, membrane blebbing on the nerve cells was observed. These events were followed either by lysis of target nerve cells or ingestion of the target cells via food-cups and their subsequent channeling into intracytoplasmic food vacuoles. Use of the TUNEL (TdT-mediated dUTP nick end labeling) technique indicated that approximately 40% of B103 cells incubated with A. culbertsoni, 20% of B103 cells cocultured with A. castellanii or with A. polyphaga, and less than 1% of B103 cells incubated with A. astronyxis at 37 C were apoptotic after 24 hr of coculture. Studies using electron microscopy indicated that Acanthamoeba trophozoites destroyed nerve cells both by cytolysis and by ingestion of whole nerve cells via food-cups.

Acanthamoeba↗

PubMed1976

Studies on the biological effects of deuteriated organic compounds. II. Morphological changes of Epidermophyton floccosum exposed to perdeuteriated n-hendecanoic acid studied with interference contrast and scanning electron microscopy.

In order to visualise the morphological changes of Epidermophyton floccosum associated with exposure to perdeuteriated n-hendecanoic acid, the architecture of the dermatophyte was investigated by means of interference contrast and scanning electron microscopy. The morphology of mycelia grown on substrate containing perdeuteriated n-hendecanoic acid, or the unlabelled analogue, was compared. The perdeuteriated n-hendecanoic acid produced a characteristic undulant effect of the hyphae. The characteristic wave-like appearance of the mycelia looked similar to the curling effect occuring after treatment of dermatophytes with griseofulvin, but was not so pronounced. Perdeuteriated n-hendecanoic acid, unlike the unlabelled analogue, also seems to cause a reduction of the number of chlamydospores perforations of the macroconidia. The changes in the morphological structure of Epidermophyton floccosum exposed to pereuteriated n-hendecanoic acid have been investigated. Morphological examination of mycelia exposed to this substance by interference contrast microscopy demonstrated a picture of defect hyphae and macroconidia. By the aid of scanning electron microscopy we have attempted to obtain a better visualization of these changes at ultrastructural level.

Chemical Phenomena↗

PubMed1995

Monoclonal antibodies recognized bovine leukocyte antigens used in immuno-scanning electron microscopy.

Antibovine leukocyte monoclonal antibodies were tested in order to use them for scanning electron microscopy in backscattered electron imaging mode. The tests revealed that numerous antibovine leukocyte monoclonal antibodies still recognize lightly glutaraldehyde prefixed antigens and can be used to identify various blood cell types. The results of these tests are presented and discussed. Clearcut differences in the surface morphology exist among bovine peripheral blood normal lymphocytes. Expression of IgM and IgG molecules was observed first of all on the surface of B lymphocyte microvilli.

Animals↗

PubMed1996

Freeze-drying: in situ observations using cryoenvironmental scanning electron microscopy and differential scanning calorimetry.

The quality of a freeze-dried product and the ease with which it can be reconstituted depend upon the morphology which develops during freezing and upon solvent sublimation. In this paper, the use of an environmental scanning electron microscope (ESEM) with a cryostage attachment is reported as a means of studying such structural evolution during the sublimation process. Results indicate that cryo-ESEM can provide a useful addition to techniques already used for the development of freeze-drying cycles, such as differential scanning calorimetry and light microscopy.

Acetates↗

PubMedDate not supplied

Validation of three-dimensional surface characterising methods: scanning electron microscopy and confocal laser scanning microscopy.

Surface characteristics of enosseous titanium implants have been known to influence the quality of osseointegration. Parameters recommended for metrical analysis should be supplemented by a topographical description. In this study, Ra values obtained by established tactile and optical profilometric methods are correlated with those obtained by stereo scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). As test specimens, standardised CVD diamond-coated titanium alloys with different microwave coating power ranging from 2,000 to 3,000 W were used. A non-CVD-coated corund grit-blasted specimen (NC) was used as reference. After coating with a CVD, power of 2,000 W Ra ranges from 4.33 to 5.69 microm depending on the method used. With increasing power of the coating process, the amplitude of the surface roughness is significantly increased to 4.53 to 6.89 microm. Ra values of the same sample obtained by different methods are also significantly different (p = 0.001). Compared with the established methods of tactile and optical profilometry, SEM and CLSM offer valid data on the surface roughness accompanied by a topographical imaging. In future studies, the underlying method should be specified to interpret roughness values correctly, as not every method is suitable for each specimen and values obtained by different methods vary extremely.

Diamond↗

PubMed1997

Evaluation of particulate embolic materials with MR imaging, scanning electron microscopy, and phase-contrast microscopy.

PURPOSE: To analyze the properties and embolic effect of microfibrillar collagen (MFC), Gelfoam powder, and polyvinyl alcohol (PVA) materials that are used in embolization procedures in the head and neck. METHODS: The shape and surface of these embolic agents were examined with scanning electron microscopy and phase-contrast microscopy. The mean number of areas of T2-weighted high signal intensity was measured on MR images in a rat embolization model to estimate the embolic effect. RESULTS: By scanning electron microscopy and phase-contrast microscopy, MFC appears fibriform and has various sizes and an irregular surface. Gelfoam is of uniform size and has a smooth surface. PVA materials are granulated and have a rough surface. MFC is somewhat suspendable and its shape changes moderately after suspension. Gelfoam is very suspendable and its shape changes rapidly. PVA showed only mild swelling. The embolic effect of MFC was the lowest of the materials examined. Large PVA particles (250 to 500 microns) showed a lesser embolic effect than Gelfoam or small PVA particles (50 to 150 microns) or medium-sized PVA particles (150 to 250 microns). No significant differences were observed among the embolic effects of Gelfoam, small PVA particles (50 to 150 microns), and medium PVA particles (150 to 250 microns). CONCLUSIONS: MFC and large PVA particles (250 to 500 microns) should be used for embolization of vascular anatomy involving potentially dangerous anastomoses. Gelfoam, PVA particles of 150- to 250-micron diameter, and PVA particles of 50- to 150-micron diameter are adequate for embolization involving homogeneous and peripheral anatomy.

Animals↗

PubMed1985

Morphology of Giardia agilis: observation by scanning electron microscopy and interference reflexion microscopy.

The flagellated protozoan, Giardia agilis, was isolated from tadpole small intestine and examined by scanning electron microscopy and interference reflexion microscopy. The general morphology of the G. agilis trophozoite is similar to G. muris and G. duodenalis, but with modifications that reflect its elongated form. Interference reflexion microscopic analysis of attachment of G. agilis reveals a pattern of focal contacts by the lateral crest of the ventral disc, the ventrolateral flange, the lateral shield, and by numerous microvillus-like appendages found along the lateral border of the trophozoite. The pattern of focal contacts was observed to be dynamic; trophozoites were observed to make and break the focal contacts in a relatively short time and to glide along the surface of the substratum without breaking focal contacts.

Animals↗

PubMedDate not supplied

A method of comparing spermatozoa with light and scanning electron microscopy.

A new method of comparing light microscopy and scanning electron microscopy in the study of small cells, such as spermatozoa, that must be examined under oil immersion is described. A grid is etched on the corner of a microscope glass slide, and its inner edges are incised. Its surface area is calculated as a function f the chamber of the critical-point drying apparatus. This method dispenses with the need for any special coverslip and enables the cells to be observed under oil immersion.

Cytological Techniques↗

PubMedDate not supplied

The collagenous architecture of articular cartilage. Correlation of scanning electron microscopy and polarized light microscopy observations.

The localization and directional orientation of collagen fibers in articular cartilage is demonstrated by scanning electron microscopy and polarized light microscopy. Vertical sections of articular cartilage show different directional orientations of collagen fibers through all zones of cartilage depending upon whether the sections are parallel or perpendicular to the cleft pattern produced when the surface of articular cartilage is pierced with a round pointed awl. Sections parallel to the cleft axis show a significant population of oblique collagen fibers which are not seen in sections perpendicular to the clefts. These oblique fiber groups show a progression from nearly radial to nearly tangential orientation from deep to more superficial zones, with the most abrupt directional change seen through the transitional zone. Within the transitional zone there is a narrow band having no vertical or horizontal collagen fibers and in which collagen fibers intersect predominantly at angles ranging between 45 and 135 degrees. The number of chondrocyte lacunae per unit area is greater in sections parallel to the cleft axis compared to perpendicular sections by a factor of approximately 1.6:1. There is therefore a greater relative number of chondrocytes in the plane of section having the greatest abundance of oblique collagen fibers, suggesting a cellular basis for the collagenous architecture observed. The results are consistent with published biophysical data relating tensile and swelling properties of all zones of articular cartilage to the cleft axis.

Animals↗

PubMed1994

Three-dimensional organization of biological tissues: a new method for investigation using scanning electron microscopy.

A new method is described which enables the visualization of hidden cellular surfaces of biological tissues. The method does not depend on the kind of fixative solution, the duration of the fixation, or the quantity of extracellular matrix. The samples are chemically dissociated with potassium ethoxide until the first individual cells appear in the solution. This initial process is followed by phase contrast microscopy, and remaining tissue is investigated with scanning electron microscopy. The method has proved more effective than conventional enzymatic techniques and is a simple, quick, and effective way to investigate the three-dimensional organization of different normal and pathological tissues.

Aorta↗