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PubMed1984

The morphology of salivary calculi. A scanning electron microscopic study.

Salivary calculi are a common disorder in the submandibular gland duct system, but the etiology and pathogenesis of the concrements remain unclear. Ten submandibular gland calculi were examined in a scanning electron microscope after critical-point drying, fracturing, and gold coating. The surface of the calculi was built up of numerous knobs covered by a smooth and occasionally filamentous substance, probably of mucinous origin. Microorganisms were commonly found at the surface. The nuclei of the calculi, which were rather homogeneous, were surrounded by lamellated structures. Between the lamellae spheroid bodies, 20-100 microns in diameter, were present. These spheroid bodies are probably of mucinous origin, which together with an amorphous granulated substance builds up the matrix. Microorganism-like structures occasionally appeared at the interface between lamellae. Microorganisms can be an important factor by providing an organic matrix in the later phase of the pathogenesis of salivary calculi. However, the nuclei did not show morphological evidence of any particular factor explaining the etiology of salivary calculus.

Bacteria↗
PubMed1991

Scanning electron microscopic analysis of mineral fiber content of lung tissue in the evaluation of diffuse pulmonary fibrosis.

The mineral fiber content of lung parenchyma in 24 cases of diffuse pulmonary fibrosis of unknown cause was determined by scanning electron microscopy and compared with that of 36 autopsy cases of histologically confirmed asbestosis and 20 autopsy cases of patients with normal lungs. Fibers were isolated from the lung using a hypochlorite digestion technique and collected on the surface of a polycarbonate filter. In addition, the types of fibers present (asbestos vs. other mineral fibers) were determined by energy dispersive x-ray analysis (EDXA). When the histologic grade of fibrosis in the cases of asbestosis was compared with the uncoated fiber content by means of linear regression analysis, it was determined that the fiber content of the 24 cases of diffuse pulmonary fibrosis of unknown cause was below the 95% confidence limit for asbestosis in every instance. Furthermore, the majority of fibers analyzed by EDXA were not asbestos in the cases with diffuse pulmonary fibrosis of unknown cause, whereas more than 90% of the fibers from the asbestosis cases were commercial amphiboles (amosite or crocidolite). It was concluded that most patients with advanced pulmonary fibrosis whose tissue samples do not meet histologic criteria for asbestosis do not have asbestos-induced fibrosis, even though there may be some history of exposure to asbestos. In such cases, scanning electron microscopic analysis of mineral fiber content and EDXA of the types of fibers present often provide useful information with regard to the correct classification of these cases.

Adult↗
PubMed1985

Influences of joint immobilization and running exercise on articular cartilage surfaces of young rabbits. A semiquantitative stereomicroscopic and scanning electron microscopic study.

The influences of joint immobilization and running exercise on the articular cartilage surfaces of the patella and lateral tibial condyle of young rabbits were investigated by the semiquantitative stereomicroscopic and scanning electron microscopic methods during a period of 8 weeks. The smoothness of the articular surfaces was disturbed already 1 week after the onset of immobilization. Leafy, slightly rough and rough surface qualities associated with superficial splits were observed. The changes were of the same nature after a longer period of immobilization. Running exercise on the treadmill (150-300 m twice a day, 12-24 min per turn, 5 times a week) led to an increase of the striated surface quality at 1 to-2-week intervals as compared with the controls. It was apparent that during immobilization remarkable changes of the articular cartilage took place within the first week, while running exercise up to 8 weeks elicited only transient or minor alterations of the articular surface.

Animals↗
PubMed1994

Scanning electron microscope observations on Parapharyngodon bulbosus (Linstow, 1899) (Nematoda: Pharyngodonidae) from Egyptian Chalcides ocellatus.

The oxyurid nematode Parapharyngodon bulbosus was collected from the lizard Chalcides ocellatus from Egypt. Male and female worms were described by light and scanning electron microscopes. The specific characteristics of the worms were defined, including; mouth opening, cuticular surface of the body, genital cone and genital papillae in the male.

Animals↗
PubMed2001

Scanning electron microscopic study of different hair types in various breeds of rabbits.

The microarchitecture of the cover hairs, wool hairs and tactile (sinus) hairs of feral, New Zealand White and Angora rabbits was studied by means of scanning electron microscopy. The morphology and variability of the cuticular scale patterns, hair cortex, medullary arrangement and profile of the hairs are described, illustrated and compared with findings resulting from conventional light microscopy, cuticular casting and medullary impregnation. All parameters examined in cover hairs presented a considerable variation along the length of the hair shaft. In wool hairs, in contrast, only the cuticular scale pattern was subject to manifest segmental variation, whereas the shaft diameter, cortical profile and medullar composition changed little over the entire length of the hair. The tactile hairs of the head were characterised by a round profile of the hair shaft, a cylindrical central medullar canal, and a thick cortex covered by cuticular scales that were arranged in a waved pattern and oriented transversally in relation to the longitudinal axis of the hair. It was concluded that the scanning electron microscopic observation of hair samples is a fast and valuable method for identifying hair types with useful applications in different disciplines such as mammalian biology, the textile industry and forensic medicine.

Animals↗
PubMed1985

Effects of synthetic blood and crystalloid cardioplegic solutions on coronary endothelium: an experimental scanning electron microscope study.

In an experimental study the effects of Fluosol DA (added with potassium chloride) on the vascular interface and endothelial cells were compared to those of crystalloid potassium cardioplegic solution using scanning electron microscope. Twenty rabbits (10 in each group) were sacrificed, the hearts with ascending aorta were immediately excised, and cold oxygenated solution was infused via a cannula inserted into the cross-clamped aorta. The hearts were left immersed in the perfusion medium for 2 hr. In the Fluosol DA group endothelial cover and endothelial cells were normal or minimal changes were seen in seven cases. Occasional breaking of intercellular attachments, small areas of denuded flow surface, and disappearance of microvilli were seen in three cases. In the crystalloid potassium cardioplegic group 7 of the 10 cases showed moderate or severe damage with large areas of denuded flow surface. The present experimental protocol represented an extreme situation where no collateral coronary blood was present. The coronary endothelial damage was obvious after the crystalloid potassium cardioplegic solution. Similar damage was not found following Fluosol DA infusion.

Animals↗
PubMed1993

[Scanning electron microscopic study on the influence of monoclonal antibody on the invasion of macrophage by Leishmania parasites].

The interaction of promastigotes of Leishmania with mouse peritoneal macrophage in vitro was studied by scanning electron microscopy. The results showed that when promastigotes had been incubated with 1/1,000 McAb for 1 h, morphological changes could be seen in most promastigotes, some promastigotes were lysed and some promastigotes although adhered to the macrophage, but no penetration could be seen. When 1/1,000 McAb had been inactivated at 56 degrees C for 1 h and then incubated with promastigotes, scanning electron microscopic examination showed the promastigotes closely adhered to the surface of macrophage with their anterior end "buried" within macrophage. The results of the present study suggested that the mechanism of promastigote-macrophage adhesion was ligand-receptor binding interaction (Figs. 1-11).

Animals↗
PubMed1983

Scanning electron microscopic observations of normal and regenerating nerve roots in the cat.

The surface morphology of normal and regenerated nerve roots was studied using correlated scanning and transmission electron microscopic methods. Nerve roots of the cauda equina were either cut and rejoined or crossed from a segment above to a segment below. Good regeneration was observed in both experimental procedures. The regenerated nerve root sheath had alterations in surface structure created by extensive growth of collagen. Despite this collagen formation, regenerated axons crossed the anastomotic site with relative ease. Surface features of the regenerated axons were similar in appearance to those of the normal axon. Schwann cells were easily recognized, as were the collagen fibers of the endoneurium, although the endoneurium was more prominent and occupied more of the interaxonal space. Macrophages were identified as round structures with a laminated surface or as a honeycomb structure. Internal features of the regenerating axons were more difficult to identify, but mitochondria and a fibrous network were observed. These studies have demonstrated the application of scanning electron microscopic methods to visualize surface structures and cells in regenerated nerve roots.

Animals↗
PubMed1985

Scanning electron microscope studies on the parasitic cycle of Coccidioides immitis.

The process involved in the in vivo conversion of the arthroconidia of Coccidioides immitis into endosporulating spherules was studied with the aid of a scanning electron microscope. By the fifth and sixth day after inoculation of laboratory mice, complete conversion had occurred in their kidneys, lungs, and spleens. The progressive stages of cleavage that occurred in the enlarged arthroconidia were initiated by invagination at several points of the cytoplasmic membrane that covers the inner surface of the developing spherule's cytoplasm was divided into progressive smaller segments. These segments were aggregated in packets and enclosed in a membranous sac. At maturity the membrane dissolved, and the endospores were freed within the spherules. Finally, the spherule wall ruptured, and the endospores were released.

Animals↗
PubMed2000

Craniofacial abnormalities induced by retinoic acid: a preliminary histological and scanning electron microscopic (SEM) study.

Exogenous retinoic acid has been found to be teratogenic in animals and man. Craniofacial defects induced by retinoic acid have stimulated considerable research interest. The present report deals with scanning electron microscopical observations of the craniofacial region concurrent with histological examination of craniofacial dysmorphism induced in rat embryos following maternal treatment treated with varying dosages of all-trans-retinoic acid (tretinoin). Two groups of pregnant rats were treated with rat embryos exposed to retinoic acid suspended in corn oil (100 mg/kg b.w. on gestational day 11.5 and 50 mg/kg b.w. on gestational day 10, 11 and 12 respectively). A third group was treated with corn oil (vehicle) while a fourth group remained untreated. A wide spectrum of congenital abnormalities, including exophthalmos, microphthalmia and anophthalmia, maxillo-mandibular dysostosis, micrognathia of both maxilla and mandible, cleft palate, subdevelopment of ear lobe, preauricular tags and macroglossia, were observed in the offspring of retinoic acid treated animals. The abnormalities were both time and dosage dependent, and characteristic of Treacher Collins syndrome when retinoic-acid was administered on gestational day 11.5. In contrast, when retinoic acid was administered were on gestational days 10-12, the defects were similar to those seen in the first and second pharyngeal arch syndrome, as well as in the oculo-auriculo-vertebral spectrum. Whereas our data support the hypothesis that all-trans retinoic-acid disturbs growth and differentiation of several embryonic cell types essential for normal craniofacial development, its mechanism of action remains unclear.

Abnormalities, Drug-Induced↗
PubMed1984

Interpretation of scanning electron microscopic images of abraded forming bone surfaces.

The experimental abrasion of forming bone surfaces was conducted so that such surfaces could be characterized. This is particularly important to bone remodeling studies utilizing scanning electron microscope (SEM) imaging of archeological material. Forming surfaces derived from subadult macaque cranial bone were treated by particle abrasion, water abrasion, sliding abrasion, brushing, manual rubbing, weight, exfoliation, chipping and replication. Acetic acid treatments were also performed. The effects of abrasive agents are specific but generally fall into rough (particle and water abrasion) and smooth (sliding abrasion, brushing, rubbing and weight) categories. Protohistoric human and Plio-Pleistocene hominid subadult craniofacial remains were observed with the SEM for comparison with experimental data. The more recent material appeared smooth, probably as a result of specimen preparation procedures using brushes. Surfaces were still interpretable as forming, however, using a more abrasion-resistant feature called intervascular ridging (IVR) described in this study. The IVR pattern is also recognized on the hominid sample, confirming the possibility of performing remodeling studies on abraded fossil material. The abrasion characteristics are somewhat more difficult to classify, however. Abrasion is defined and discussed relative to remodeling studies and taphonomy. The usefulness of the experimental data reported here, however, in paleoenvironmental reconstruction, has yet to be fully realized. Acid and mechanical preparation techniques are briefly addressed. It is concluded that it is possible to characterize a forming surface as abraded according to the findings of this study and that acid, if handled with care, will more likely preserve microanatomical surface detail. It would also be in everyone's interest to employ a less abrasive cleaning regime on archeological specimens.

Animals↗
PubMed1993

Effect of irrigation fluids on the articular cartilage: a scanning electron microscope study.

Four irrigation solutions, two for general arthroscopic examination and two for electrosurgery, were evaluated for their effects on the ultrastructure of the articular cartilage surface using an animal model with a scanning electron microscope (SEM). The murine knee joints were irrigated continuously for 1 or 2 h with normal saline, Ringer's lactate, 3% sorbitol, or distilled water, respectively. The articular cartilage of the patella was evaluated in situ; that is, the cartilage was kept intact as it related to the underlying bone tissue, so that artifacts during the biopsy procedure could be prevented. Results of the study showed no significant differences among the four solutions and the unirrigated control group. We conclude that Ringer's lactate, normal saline, distilled water, and 3% sorbitol can all be safely used as irrigation solutions in arthroscopic surgery.

Animals↗
PubMed1979

Effects of motion load changes on tendon tissues and articular cartilage. A biochemical and scanning electron microscopic study on rabbits.

The motion load of rabbits was increased by treadmill running during a 5-d period. One group ran on a level surface, while the other ran uphill. After the running, the glycosaminoglycan metabolism and scanning electron microscopic photographs of different tendon, ligament and cartilage samples were analyzed. Uphill running decreased the glycosaminoglycan metabolism of articular and costal cartilage. The clearest irregularities of articular cartilage studied by scanning electron microscopy were also seen in the uphill running group. Increasing the motion load increased the glycosaminoglycan synthesis of stretched tendons. The possible combination of general inhibitory and local stimulating effects is discussed.

Animals↗
PubMed1978

The formation and final structure of the oocyst wall of Eimeria acervulina: a transmission and scanning electron microscope study.

The formation and final structure of the oocyst wall of Eimeria acervulina is described, based on a detailed electron microscope study of the maturing oocysts. After fertilization of the macrogametocyte the wall-forming bodies of type I progressively undergo disaggregation into smaller bodies and eventually move into spaces left by the pellicular membranes of the zygote, which simultaneously separate and elevate away from the zygote cytoplasm to form the outer layer of the oocyst wall. A newly formed membrane separates this layer from the cytoplasm. Following the formation of the outer layer, another membrane separates and elevates away from the cytoplasm, and the wall-forming bodies of type II, which by now have migrated to the periphery, move into the spaces and fuse together to form the inner layer of the oocyst wall. A newly formed membrane separates this layer from the cytoplasm. The wall of the young oocyst thus consists of two membrane-bound layers of approximately similar thickness; the outer layer being osmiophilic whilst the inner one is paler. An overlaying membrane covers the oocyst. The surface of the oocyst wall was smooth in appearance when viewed with the scanning electron microscope.

Animals↗
PubMed1989

Microleakage channels: scanning electron microscopic observation.

Resin casts were made of microleakage channels surrounding amalgam restorations in vitro. After demineralizing the tooth and digesting the remaining organic matrix, the amalgam restorations covered with the resin casts were examined using a scanning electron microscope. An extensive reticular network of channels was observed on restorations which were placed in cavities lined by smear layers. Amalgam restorations placed in cavities devoid of smear layers exhibited fewer microleakage channels.

Dental Amalgam↗
PubMed1984

Scanning electron microscopic studies of root dentin surfaces treated with citric acid, elastase, hyaluronidase, pronase and collagenase.

The effect of topical application of various enzymes to citric acid-demineralized root surface dentin was evaluated using the scanning electron microscope. All of the enzyme treatments appeared to expose more collagen than demineralization alone. Collagenase application appeared to clear all ground substance from the collagen fibrils and may have hydrolyzed some of the fibrils themselves. The other enzymes appeared to clear partially the intercollagenous ground substance.

Citrates↗
PubMed1980

A comparison of the marginal adaptation of retrograde techniques: a scanning electron microscopic study.

An investigation of the most popular retrograde technique for their marginal adaptation to dentin was attempted. Forty extracted maxillary central incisors were instrumented and obturated, and various apical procedures were performed. The scanning electron microscope was used to record the results. Retrograde amalgam, heat-sealed gutta-percha, and the apicoectomy control showed average marginal defects from 22 micron to 104 micron, while cold-burnished gutta-percha exhibited an average defect of only 1.8 micron. The marginal defect produced by cold-burnished gutta-percha is less than one tenth as large as the best of the other techniques.

Apicoectomy↗