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PubMedDate not supplied

Extra internal hair cells. A scanning electron microscopic study.

The extra internal hair cell (EIHC) of the human cochlea was observed by means of a scanning electron microscope. The EIHC was found not infrequently in all turns of the human cochlea. It was located medial to the IHC row. The inner pillar cells showed an abnormal structure. The anatomical relationships between the displaced IHC and EIHC, and the inner pillar cell were classified into five types. The origin of these anomalies is discussed form an embryological viewpoint.

Aged↗
PubMed1995

Scanning electron microscope examination of scale-like spines on the rostellumm of five Davaineinae (Cestoda, Cyclophyllidea).

The study by scanning electron microscope of the scolex of Cotugnia polyacantha, Raillietina (R.) echinobothrida, R (R.) tetragona, R. (R.) tunetensis and R. (Skrjabinia) cesticillus allowed us to demonstrate the presence, on the rostellum of each individual, of scale-like spines. We believe that these scale-like spines represent a new character of diagnosis for the whole of the Davaineidae.

Animals↗
PubMed2000

Scanning electron microscopic evaluation of nonocclusive excimer laser-assisted anastomosis in rabbits.

BACKGROUND: The nonocclusive Excimer laser-assisted bypass technique has been described in previous studies and proved to be a promising bypass operation in vascular brain surgery. Little is known about the morphological regeneration process of the laser-assisted anastomosis in time. By way of a scanning electron microscopic study we examined the way in which the anastomosis site created by the nonocclusive Excimer laser-assisted anastomosis technique becomes endothelialized. METHODS: In 14 rabbits the internal jugular vein was placed in a loop on the abdominal aorta. The distal anastomosis was made using the nonocclusive Excimer laser-assisted technique. The proximal anastomosis was made either laser-assisted or conventional end-to-side. After clipping of the aorta between the two anastomoses sites the vein served as a bypass. To evaluate the endothelialization at the laser-assisted anastomosis site in time, a scanning electron microscopic study was performed. RESULTS: In the first hours after the bypass operation a new intimal surface is formed by fibrin and activated platelets. Some leukocytes are seen during the first days. The endothelialization process of the laser-assisted anastomosis site begins one day after the operation. The gradual endothelialization process evolved along two lines. First, endothelial cells grow from the side of the aorta to the bypass. Second, after one day solitary (blood-borne) endothelial cells deposit on the laser edge and the sutures, covering the platelet aggregates. CONCLUSIONS: The endothelialization of the Excimer laser-assisted anastomosis is more or less completed 9 days after the operation. The edge created by the laser becomes smoother after a few days and is gone for the most part after 9 days.

Anastomosis, Surgical↗
PubMed1981

Morphological observations of peripheral nerves by the scanning electron microscope.

In order to observe a normal peripheral nerve and a changed peripheral nerve by means of a scanning electron microscope, the present study was carried out. In the changed nerve fibers, they were enveloped by many processes of hypertrophied Schwann cells, and the processes of the Schwann cells seemed to make a pseudosyntitium-like structure with each other. From this finding, it was speculated that these Schwann cells seemed to follow the reverse process in the development of normal peripheral nerve fibers.

Animals↗
PubMed1976

[Enamel bundles and lamellae under the scanning electron microscope].

Lamellae, tufts and cracks were found in the enamel near the dentionenamel junction. When investigated by the scanning electron microscop, lamellae and tufts were very similar to each other as to their structure. Lamellae appeared in two kinds: 1. Organic material originating in the dentionenamel membrane filled the whole space. 2. The space was empty, yet an organic membrane was covering the walls of adjacent prisms. Tufts and lamellae differed merely in their lenght. The walls of the cracks lacked organic material, the prisms being damaged or their course interrupted.

Bicuspid↗
PubMed2002

Osteogenic potential of rabbit marrow stromal stem cells cultured in vitro: a histochemical and scanning electron microscopic study.

OBJECTIVE: To further investigate the osteogenic potential of rabbit marrow stromal stem cells cultured in vitro. METHODS: Rabbit marrow stromal stem cells were isolated by density gradient centrifugation method and amplified in the flasks, using the osteogenic inducing conditions (OGC) as the culture media. The osteogenic potential of marrow stromal stem cells were investigated by means of bone-seeking fluorescence (tetracycline) labelling, Alizarin red S (ARS) staining, Alcian blue-Sirius red (AS) staining, and scanning electron microscope. RESULTS: After being passaged, the marrow stromal stem cells increased in number, became confluent and formed multi-layer structure. The stromal stem cells excreted innumerable tiny granules, heaping up on the cell body and merging gradually into foggy substances. These foggy substances kept on enlarging and formed round, oval, or flake-like nodules. These nodules revealed bright golden yellow fluorescence under fluorescence microscope when labelled with tetracycline. Histochemical study with specific new bone staining with ARS revealed positive calcium reaction, both denoting that they were newly formed bone tissues. After they were stained with AS, collagen and acid mucopolysaccharide were shown. Under scanning electron microscope, three types of cells with different configurations were found. They were globular cells, spindle-shaped cells and polygonal or polygonal cells. Granules were excreted from the cells and heaped up on the cell body. Needle-shaped and irregularly rectangular crystals also appeared and agglomerated with the granules to form nodules and trabecula-like or flake-like structures. CONCLUSIONS: Sequence of events of bone formation by rabbit marrow stromal stem cells cultured in vitro is fully depicted and confirmed, which provides the foundation for further investigating the mechanisms of osteoblast differentiation from marrow stromal stem cells and the possible application in orthopaedics.

Animals↗
PubMed1979

Early morphological changes of the corneal epithelium after burning with hydrochloric acid. A scanning electron microscope study.

The morphological changes of the corneal epithelium after burning with hydrochloric acid were examined using a scanning electron microscope. A drop of hydrochloric acid of differing concentrations (1--0.000001 N HCl) was applied under standardized conditions to normal rabbit eyes for a reaction period of 5 or 30 min. The changes in the cell surface, which are dependent on the concentration of the acid, include a loss of microvilli and microplicae, outlining of the cell nucleus, disruption of the intercellular spaces, cell desquamation and even the most severe damage to the cell membrane and cytoplasm of the corneal epithelial cells.

Animals↗
PubMed1984

Scanning electron microscopic analysis of Kupffer cell proliferation after zymosan administration.

Rat Kupffer cells were observed and counted under a scanning electron microscope after a single dose of zymosan. The cell number increased after 24 h and reached 2 times the control after 72 h. The percentage of cells presenting numerous microvilli increased from 24% to 86% over the same period. Carbon clearance, a measure of phagocytic activity, decreased temporarily, regained control values after 12 h, and attained a 4-fold elevation at 72 h. Phagocytic activity paralleled Kupffer cell number, but increased more relatively. This result probably reflected activation of resident Kupffer cells as noted by numerous thick microvilli.

Animals↗
PubMed1996

Scanning electron microscopic characteristics of small-incision intraocular lenses.

PURPOSE: To evaluate the surface characteristics of commonly used, small-incision, intraocular lenses (IOLs). METHODS: Representative samples of five groups of foldable IOLs (4 silicone and 1 acrylic) underwent surface and edge-finish examination using a slit lamp. The IOLs were folded using a folding block and forceps. All the IOLs then were examined using a scanning electron microscope. A one-piece polymethylmethacrylate IOL was used for comparing surface-finish characteristics. The IOLs were examined for optic surface quality, edge finish, haptic, haptic/optic junction, and possible post-folding modifications. RESULTS: Slit-lamp evaluation of the surface quality of all of the silicone lenses demonstrated a smooth finish of the optic surface, edge, and haptics. Scanning electron microscopic analysis of the IOLs demonstrated adequately finished haptics or footplates and optics. Excess molding flash was seen on the edges of the some of the silicone IOLs, and no molding flash was observed on others. The acrylic IOL had a somewhat sharper optic edge. Irregular finish of the haptic/optic junctions of some of the IOLs (both silicone and acrylic) was noted. CONCLUSIONS: Currently available foldable IOLs have demonstrated adequate lens finish. However, irregularities of the haptic/optic junctions and molding flash are present on most IOLs evaluated, indicating room for improvement in the finish of foldable IOLs. Phacoemulsification with capsular bag IOL placement may decrease the clinical significance of these relatively subtle lens finish irregularities.

Acrylamide↗
PubMedDate not supplied

Bone marrow leukemias and lymphoproliferative disorders: scanning electron microscope diagnosis.

This work considers the primary diagnosis of bone marrow leukemias and lymphoproliferative disorders by using the scanning electron microscope (SEM). A total of 14 cases are studied, including 2 demonstrating bone marrow hyperplasia only. The utility of employing the ordinary pathology glass microslide with routine stain is emphasized, as well as certain capabilities of the SEM, including backscattered electron image, secondary electron image, and measurement program. Bone marrow hyperplasias, myeloid leukemias, and lymphoproliferative disorders are analyzed by comparing specific ultrastructural features, such as cell sizes, nuclear chromatin configuration and composition, nucleoli, nuclear contour, and cytoplasmic constituents, including granule population with sizes of such granules. These features set apart the common bone marrow neoplasms and can be a determinant in case diagnosis.

Adult↗
PubMedDate not supplied

Effect of mechanical trauma on the tooth germ of rat molar--a scanning electron microscope study.

OBJECTIVE: Clinical and histopathological evaluation of mechanical trauma on the development of maxillary first molar with Scanning Electron Microscope. DESIGN: Experimental study with four newborn Wistar rats. Trauma induced on 1st, 3rd, 7th and 10th postnatal days with dental K file. Right first molar region of the maxilla was the experimental side and the left side as control. Animals were sacrificed on the 42nd Postnatal day when the teeth came into functional occlusion. Teeth were evaluated clinically and SEM study of the crown was performed. RESULTS: Marked disfigurement of cusps, roughened defective, enamel, crown dilacerations and enamel hypoplasia were observed. Damage was less severe to the tooth subjected to trauma on the 10th postnatal day.

Age Factors↗
PubMed1997

Galanin and cholecystokinin in cultured magnocellular neurons isolated from adult rat supraoptic nuclei: a correlative light and scanning electron microscopical study.

Cultured magnocellular neurons, isolated from adult rat supraoptic nuclei, were characterized by immunocytochemistry, using the avidin-biotin-peroxidase complex and antisera to vasopressin, oxytocin, galanin and cholecystokinin. Light microscope examination of the immunostained cultures revealed the presence of vasopressin- and oxytocin-like immunoreactivity, as well as neurons containing either galanin- or cholecystokinin-like immunoreactivity. In contrast, no significant galanin- or cholecystokinin-like immunoreactivity could be observed in freshly dispersed cells. Correlative scanning electron microscopical observations in the secondary electron imaging mode revealed that the stained neurons appeared significantly brighter than the unstained structures. Complementary observations with toad brain sections (preoptic area), immunostained for galanin, led to the same result. Considering previous results, it is suggested that the presence of galanin- and cholecystokinin-like immunoreactivity in the cultured neurons and its virtual absence in freshly dispersed cells is indicating a participation of these peptides in the regenerative processes taking place during culture. It is further concluded that the avidin-biotin-peroxidase method is suitable for correlative light and scanning electron microscopical studies of smooth surfaces and cultured cells.

Animals↗
PubMed1986

Upper genital tract abnormalities in the Syrian hamster as a result of in utero exposure to diethylstilbestrol. II. Scanning electron microscope analysis of endometrium cell surfaces.

Using scanning electron microscopy (SEM), we show that an in utero exposure to diethylstilbestrol (DES) will induce endometrial abnormalities postnatally. These changes are magnified when a subsequent postnatal DES treatment is given. More specifically, changes in cell surface morphology are associated with alterations in cell size and shape (from columnar to cuboid/squamous), and in microvilli and mucus secretion. Uteri from hamsters treated postnatally with DES and derived from normal (CD) or DES-treated mothers (DD) show that accumulated mucoid secretion products are not expelled in the uterine lumen but are "stored" in cystic dilated glandular spaces of the fibrocellular stroma of polyps and papillae filling the uterine lumen. Uteri from female hamsters that have been prenatally treated with DES (DC) show endometrial mucosal crypts containing mucus and other cell debris including migrating granulocytes. In all cases, DES-treated uteri show mucosal cell surface pleomorphism in the sequence DD greater than CD greater than DC Merocrine and/or cystic secretions were observed. Microvilli cover cell surfaces and include some rare and peculiar long microvillous growth. In contrast, DC hypoplastic uteri present no secretory activity. Structures similar to those described for CD uteri can be observed only after 250 days of age in DC uteri. This report confirms and complements previous observations, favoring the choice of the hamster as an animal mode for the study of endometrial carcinogenesis.

Abnormalities, Drug-Induced↗
PubMed1986

Microvascular smooth muscle cell quantitation from scanning electron microscopic preparations.

A morphometric method to analyze scanning electron micrographs (SEM) of microvascular smooth muscle cells (SMC) is validated using intestinal arterioles. Features easily obtained from these microvasculature preparations are counted (number of tapers and number of complete wraps in the central 87% of the vessel, which is one-third of the vessel's circumference) or measured (vessel diameter and vessel segment length). These data allow the determination of wraps around the values as determined by circumferential examination and quantitation of the vascular segment or an alternative SEM quantitation method (Miller et al., 1986). The method described herein provides a relatively easy way to determine microvascular SMC parameters.

Animals↗
PubMed2003

Charge-related problems associated with X-ray microanalysis in the variable pressure scanning electron microscope at low pressures.

In variable pressure scanning electron microscopy (VPSEM) the current data suggests that considerable caution is required in the interpretation of X-ray data from nonconductive samples, depending on the operating conditions. This article reviews some of the documented approaches and presents data that illustrate the nature and magnitude of the effects of charge above, on, and in the sample on the detected X-ray emissions from the sample and from elsewhere within the VPSEM specimen chamber. The collection of reliable and reproducible X-ray data has been found to require relatively high specimen chamber gas pressures, at the upper end of or beyond the available pressures for most VPSEMs. It is also shown that sample characteristics, including composition, strongly influence local charge effects, which can significantly affect the primary electron landing energy and consequently the resultant emitted X-ray signal under low pressure environments.

Electron Probe Microanalysis↗