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PubMed1989

Application of scanning electron microscopy and energy-dispersive X-ray analysis to the solution behaviour of Zn-insulin: precipitation phenomena.

Scanning electron microscopy (SEM) has been applied in combination with energy dispersive X-ray analysis (EDAX) to identify and analyse particles or particulate matter, occasionally present in clear neutral Zn-insulin solutions. SEM photographs revealed the existence of three different types of precipitate, consisting of particles with a crystalline, amorphous or gel-like nature, respectively. At present, it is not clear which conditions lead specifically to each of these three types of precipitate. The advantages of the EDAX method are shown. The technique enables semi-quantitative analysis to be performed on a single particle as small as 0.2 microns. It was demonstrated with the EDAX method that the particles occasionally found in clear Zn-insulin solutions contain insulin as well as Zn in roughly the same ratio as in the insulin starting material. It is concluded that the EDAX method has great potential in pharmaceutical technology, inter alia for the analysis of emulsion systems (in the frozen state), as well as suspensions and particulate matter in injection fluids. This technique is particularly useful in the latter case, due to its applicability to extremely small sample sizes.

Animals↗
PubMed1984

Scanning electron microscopy of the multifilament IUD string.

Fifteen multifilament strings on Dalkon Shield IUDs removed from patients were evaluated with scanning electron microscopy. All fifteen showed deterioration of the sheath which encloses the smaller inner filaments. The greatest area of deterioration was at the attachment knot which is usually intrauterine. Deterioration of the sheath also occurs when the device is within the uterine wall or intraperitoneal. The risk of pelvic infection may be attributed to this deterioration of the sheath and contamination from that site.

Bacterial Infections↗
PubMed1979

Study of Biopsies from lesions of the oral mucosa by scanning electron microscopy (S.E.M.).

Surface epithelial cells from 55 biopsies including lichen planus, leukoplakia and squamous cell carcinoma were studied by scanning electron microscopy. The surface structures of the various oral lesions demonstrated morphological differences. After more information has been collected, the method of SEM may be of value for the recognition of pre- and early neoplastic lesions in the oral cavity.

Biopsy↗
PubMed1974

Scanning electron microscopy of human lymphocyte-sheep erythrocyte rosettes.

Human lymphocytes of known B or T derivation were examined by scanning electron microscopy (SEM) before and after rosetting with SRBC. After collection of the cells onto silver membranes the samples were prepared for SEM by the critical point drying method. Sheep RBC frequently underwent sphero-echinocyte transformation and multiple projections extended from their surfaces. This was readily noticeable after storage of SRBC in the cold and washing in Hanks, but more prominent after rosetting. These erythrocyte surface alterations were less apparent when freshly withdrawn cells were used. Spontaneous sheep erythrocyte rosettes (E-R), a marker for human T lymphocytes, were prepared with normal peripheral blood lymphocytes (PBL), thymic cells, and cultured T cells. EAC-rosettes (EAC-R), used to identify B lymphocytes with complement receptors, were prepared with normal PBL and cultured B cells. The majority of rosetting T lymphocytes had generally smooth surfaces while about 20% had an intermediate number of microvilli and 15% were more villous and indistinguishable from villous B cells. Studies of rosetting thymocytes and cultured T cells however indicated that the surface of some T cells alters on rosetting, becoming more villous and thus account for the higher numbers of villous T cells seen in E-rosettes. Point to point contact sites between SRBC and T lymphocytes were more frequent than broad zones of attachment. The majority of rosetting B lymphocytes had multiple microvilli, about 25% had a moderate number of microvilli and less than 10% had smooth surfaces similar to those of most T cells. Areas of contact between EAC and B lymphocytes were frequently broad zones of attachment. The study confirms that in many cases B and T lymphocytes can be distinguished by their surface architecture as seen under the SEM; however, about 20% of rosetting B and T cells have similar surfaces with intermediate numbers of surface microvilli and cannot be distinguished by SEM without parallel immunologic identification.

Animals↗
PubMed1992

Scanning electron microscopy of eggs of Mansonia bonneae (Diptera: Culicidae).

The egg of Mansonia bonneae (Edwards) is described by means of scanning electron microscopy (SEM) and compared with other sympatric species reported recently in previous studies. Ma. bonneae differed from Ma. uniformis (Theobald), Ma. indiana (Edwards), Ma. annulifera (Theobald), and Ma. annulata (Leicester) in that it has six variably sized dog-tooth spines surrounding the raised central micropyle, and only a single nipplelike stud at the anterior one-third of the egg. A key for identification of the eggs of the five sympatric Mansonia species under SEM is presented.

Animals↗
PubMed1979

Freeze substitution for preservation of ciliated surfaces for scanning electron microscopy.

A technique is described for arresting rapid movement of living cells and preserving their fine surface structures for scanning electron microscopy. Rapid freezing is recommended as the method of immobilization and freeze substitution has been employed to fix and dehydrate the specimens; this technique is more reliable than osmium fixation, both in terms of obtaining a much higher proportion of good results and in the improved preservation of detail. Various techniques of substitution have been investigated for best preservation, and the roles of the constituents of the substitution mixture have been discussed.

Alcohols↗
PubMed1990

High resolution scanning electron microscopy of the subplasmalemmal cytoskeleton in human odontoblasts.

The subplasmalemmal cytoskeleton in human odontoblasts was studied by high resolution scanning electron microscopy. The odontoblast layer was isolated and exposed to formaldehyde, glutaraldehyde, and OsO4 for some specimens, while the membraneous structures and soluble proteins in the dental tissue were removed by Zenker's solution and 1% OsO4 for other specimens, without further fixation of the remaining components. The cytoskeletal elements comprised a dense network of interlacing filaments of different diameters in the cell body. Most cytoskeletal elements were parallel to the axis of the cell processes situated inside the dentinal tubules. The appearance and orientation of the investigated subplasmalemmal cytoskeletal elements was unaffected by the choice of method. Both methods confirm the presence of a subplasmalemmal cytoskeleton in human odontoblasts.

Actin Cytoskeleton↗
PubMed1985

Adherence of Escherichia coli in pathogenesis of endometritis and effects of estradiol examined by scanning electron microscopy.

Escherichia coli was inoculated into the uterine lumen of ovariectomized rats, and the endometrial surfaces were examined by scanning electron microscopy. Adherence of E. coli to the epithelium and destruction of the surface leading to purulent endometritis were noticed. When rats were treated previously with estradiol, adherence of E. coli was not detected.

Animals↗
PubMed2000

Morphology of larval antennae and mouthparts of four Indian sand flies (Diptera: Psychodidae) by scanning electron microscopy.

The mouthparts and antennae of the fourth-instar larvae of four sand fly species were studied using scanning electron microscopy. The morphology of the clypeus, labrum, mandible, maxilla, mentum, and antennae were compared for Phlebotomus argentipes Annandale & Brunetti, P. papatasin (Scopoli), Sergentomyia babu babu (Annandale), and S. bailyi (Sinton). Most of structures exhibited species-specific features, particularly the characteristics of the antennae. P. papatasin larvae had heart-shaped antennae, a long mandible, stout maxilla, and a heavy mentum with large teeth. In contrast, P. argentipes larvae had dumbbell-shaped antennae and a singular club-shaped labrum. The antennae of S. b. babu were ovoid, whereas those of S. bailyi were elliptical. The labrum of S. b. babu was lanceolate, whereas that of S. bailyi was rounded and exhibited a small, thick projection with several folds. The teeth of the mentum of both Sergentomyia species were shorter than those of the Phlebotomus species. Species-specific differences in the morphology of larval mouthparts and antennae indicate that it may not always be necessary to rely on adult morphology to identify sympatric phlebotomines.

Animals↗
PubMed1984

Scanning electron microscopy of the rat exocrine pancreas.

The three-dimensional architecture of the rat exocrine pancreas was studied by scanning electron microscopy (SEM) with the HCl digestion method. The treatment with HCl effectively removed connective tissue elements enclosing the ducts and the acini. Thus their shapes and relations were clearly revealed under the SEM. Furthermore fine surface features of the acinar or ductal cells were also demonstrated. Although recent studies have suggested that the pancreas might be reticular in architecture due to anastomoses between adjacent ducts or acini, the present investigation confirmed that rat pancreas is a compound acinar (alveolar) gland. Excretory ducts extended into interlobular spaces, branching dichotomously. Intercalated ducts, which showed an almost constant thickness, issued directly from the excretory ducts, entered the pancreatic lobuli, and branched several times to connect with numerous acini of varying size and shape. Basal surfaces of the excretory ducts showed conspicuous reticular undulation, while those of the intercalated ducts were smooth except for some areas with fine unevenness near the epithelial cell boundaries. It remains to be elucidated whether these basal structures of the intercalated ducts are involved in their assumed function, i.e., the secretion of water and bicarbonate in pancreatic juice. The acinar lumen was a narrow secretory canaliculus covered with finger-like microvilli. Intercellular canaliculi branched from the central canaliculus, taking a straight course toward the acinar cell base, and ended blindly. Some canaliculi extended to the close vicinity of the basement membrane, providing a locus minor is resistantiae for the leakage of pancreatic enzymes into blood. The SEM findings on the canalicular system were confirmed by light microscopic observation of the pancreatic excretory passages stained by the rapid Golgi method, and by three-dimensional reconstruction of the pancreatic acini from serial semithin sections.

Animals↗
PubMed2001

Biliary tract of the rat as observed by scanning electron microscopy of cast samples.

The three-dimensional distribution of the biliary tract in the rat was studied by scanning electron microscopy of biliary casts. The casts were prepared by a retrograde infusion of a low viscosity or monomeric methacrylate resin mixture into the common bile duct. No resin flow from the bile canaliculi to sinusoidal capillaries was ever noted. Bile canaliculi formed intricate meshworks and drained via the Hering's canals into the bile ductules. The bile canalicular meshworks of adjacent lobules intercommunicated with each other. The bile ductules formed a marked periportal plexus around the portal vein branch, and drained into the intrahepatic bile duct running along the portal vein branch. The junctional zone of the Hering's canal and bile ductule usually showed an ampullary dilation. When the Hering's canal directly drained into a thick bile ductule or into a periportal plexus of bile ductules, such an ampullary dilation at the origin of the bile ductule was never replicated. The extrahepatic bile duct protruded many crypt-like projections which presumably corresponded to parietal glands. It is suggested that the periportal plexus of bile ductules may store the bile as a substitute for the gallbladder.

Animals↗
PubMed2002

Three-dimensional helical coiling structures and band patterns of hydrous metaphase chromosomes observed by low vacuum scanning electron microscopy.

Helical coiling structures and band patterns of hydrous metaphase chromosomes were documented three-dimensionally by low vacuum scanning electron microscopy (SEM). Fixed or unfixed isolated Chinese hamster metaphase chromosomes were stained with platinum blue (Pt blue) and observed in the backscattered electron mode for low vacuum SEM without any hypotonic treatment or drying processes. Fibrous structures were shown both in the fixed and unfixed hydrous chromosomes; helical chromatid coils and their subcoils were clarified especially in the fixed chromosomes having contrasting alternative bands of light and darkness, while the translucent perichromosomal matrix and compact fibrous structures were recognized in the unfixed chromosomes. The helical coils were more clearly represented in a loosened chromatid of metaphase chromosomes. Treatment with a tris-HCl buffer solution and Pt blue staining in a hydrous condition successfully produced banding patterns similar to G-bands on metaphase chromosomes. These banded chromosomes observed by low vacuum SEM were also analyzed stereoscopically by field emission SEM after critical point drying. These findings indicate that: 1) native or unfixed chromosomes maintain the compact arrangement of high-order helical structures covered with the peri-chromosomal matrix; 2) helical coiling appearances of chromatids frequently observed in previous papers might be caused by loosening of the final level of the high-order structure of the metaphase chromosome; and 3) banding patterns might be produced by the rearrangement or reorganization of chromatin fibers at the 30 nm fiber level after the extraction of some chromosomal components including the peri- or intra-chromosomal materials during the banding procedure.

Animals↗
PubMed1994

The micromorphology in vivo of the buccocervical region of premolar teeth in young adults. A replica study by scanning electron microscopy.

The buccal surfaces of premolar teeth are common sites of gingival recession, generally attributed to overzealous oral hygiene. Scanning electron microscopy (SEM) of replicas made from dental impressions was applied to document the micromorphology of the buccocervical region of all premolar teeth in 27 dentally healthy, young adults. The SEM observations were correlated with clinical examination. Of the 216 sites, one-third, predominantly the maxillary first premolars, had gingival recession, but fewer than 50% were clinically discernible. The exposed roots were devoid of cementum, and the dentinal surface was smear-like or dotted with tubular apertures from which droplets of fluid extruded. SEM of replicas of gingiva, recorded as clinically healthy, frequently showed signs of inflammation: fluid exudate and distortion of gingival contour by swelling. The cervical enamel of healthy and affected sites showed characteristic periodic fissure-like cracks, probably enamel tufts. The high frequency of subclinical gingival recession, exposed cervical dentin, and gingival inflammation in dentally healthy young adults, in the absence of abrasion of hard or soft tissues, indicates the need to review conventional concepts of initiation of buccal recession and root exposure.

Adult↗
PubMedDate not supplied

Scanning electron microscopy of vocal cord hyperplasia, keratosis, papillomatosis, dysplasia and carcinoma.

The vocal cord fine surface structure was examined by scanning electron microscopy (SEM), and the observations related to the light-microscopical (LM) findings after embedding and cutting. The SEM micrographs were assessed using a rating system based on 7 parameters. The proportion of "normal" and "abnormal" SEM areas varied within the respective histologic groups. There was, however, a significant difference between the SEM ratings in the group with hyperplasia-keratosis, with or without mild dysplasia, compared to the groups with severe dysplasia-carcinoma in situ and invasive squamous cell carcinoma. In the small number of cases with moderate dysplasia and juvenile laryngeal papilloma, the SEM ratings displayed pronounced disparity.

Carcinoma↗
PubMed1998

The presence of lymphatic stomata in the ovarian bursa on the European beaver as shown by scanning electron microscopy study.

The internal and external epithelial sheets of the ovarian bursa in the European Beaver were examined using scanning electron microscopy. Two types of epithelial cells were found on both surfaces, but only in the areas of the cuboidl cells were the lymphatic stomatae created. This suggests that the absorption and passage of fluid, particles and cells between the peritoneal and ovarian bursa cavities and lymphatic lumen in the beaver are possible.

Animals↗
PubMed2004

Scanning electron microscopy of the infundibulum, ampulla, and eggs of mice.

The objective of the study reported here was to use scanning electron microscopy (SEM) to discover and describe the details of three-dimensional profiles and the natural (not surgically disturbed) topography/location of the infundibulum in the mouse. It will help new investigators to more quickly identify the infundibulum for successful transfer of microinjected eggs through a small opening into the oviduct/ampulla of pseudopregnant female mice for producing transgenic mice. Results of the study also illustrate the geographic orientation and natural topographic features of the ovary, infundibulum, ampulla, oviduct, and uterus. The presence of cilia on the surface of the crown foldings in the longitudinal section of the infundibular head stained with 1% toluidine blue provided direct evidence that evagination of the internal cilia of the infundibulum/oviduct results in formation of the infundibular crown. The new observation of the narrowing region of the infundibular head after surgical removal of the crown also suggests that formation of the infundibular crown may have resulted from the "evagination process" of internal cilia of the infundibulum/oviduct surface. The results also provide new evidence that the crown, terminal opening, and appearance of the left and the right infundibula of the same mouse differ.

Animals↗
PubMedDate not supplied

[The surface status of polished restoration biomaterials after the use of a sodium bicarbonate spray: scanning electron microscopy].

The effects of an air-abrasive system on polished surfaces of restorative materials have been studied using scanning electron microscopy, metrology and profilography. Polished surfaces of composite resin, of amalgam and gold alloy show different alteration types in microtopography, in profile tracings and significant increased surface roughness after air-abrasive spraying; but ceramic and non-precious alloy surfaces are not affected. The composite resin surfaces should be repolished and amalgam and gold alloy surfaces made glossy after use of an air-abrasive system.

Bicarbonates↗