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PubMed1986

Scanning electron microscopy of antigen induced arthritic joints. I. Inflammatory cell interactions at synovial-meniscal surfaces during the Arthus response.

Scanning electron microscopy has been used to study experimental antigen induced arthritis, providing a unique perspective of the early inflammatory events. An initial aggregation of acute inflammatory cells was noted at the synovial-meniscal junction with maximal numbers observed between 12 and 24 h post challenge. Variations in cell surface ruffling, which may represent different phases of activation, were observed throughout the Arthus response. By 48 h post challenge the meniscal and synovial surfaces were covered by a mat of fibrin and degraded cell remnants.

Animals↗

PubMed1988

IgG receptors on eosinophils--using immune scanning electron microscopy.

Using carboxylate modified latex particles covalently conjugated with anti-IgG, IgG receptors on eosinophils were examined with scanning electron microscopy (SEM). After block and inhibition tests, significant number of latex particles were confirmed to bound on the surface of eosinophils. Earlier reports described that density of eosinophils decreased in hypereosinophilic patients and the heterogeneity of eosinophils came into focus. Our experiment revealed that eosinophils of hypereosinophilic patients had more IgG receptors than those of normal volunteers. This difference might be due to the heterogeneity of eosinophils.

Antigens, Differentiation↗

PubMed1988

A comparison of fixatives suitable for scanning electron microscopy of Habronema spp.

Members of the genus Habronema (Nematoda: Habronematidae) were preserved in 4 fixatives for examination with scanning electron microscopy (SEM). Tegumental features of the anterior and posterior extremities of these specimens were compared to evaluate the effect of the fixatives: modified Flemming's solution, glutaraldehyde (GA), Karnovsky's fixative and 70% ethanol. Fixatives were assessed on the appearance of the tegument, evidence of any wrinkling, shrinkage or swelling and the degree of extension in the male tail. Seventy per cent ethanol gave the most satisfactory results.

Animals↗

PubMedDate not supplied

[Comparison of various immune surface labeling methods for scanning electron microscopy with the example of a surface antigen protein of the yeast Candida albicans].

The labeling of immunocomplexes for scanning electron microscopy (SEM) is a fairly new technique, and the various procedures, that have been proposed, have not yet been compared. Such comparative evaluation was performed with Candida protease as a target antigen. This secretory enzyme of the opportunistic yeast Candida albicans can be localized on the surface of fungal blastopores and mycelia, both after growth in proteinaceous medium and upon infection of murine peritoneal macrophages. The presence of the protease antigen was confirmed by immunofluorescence and by immunoperoxidase-light microscopy. The decoration of protease - anti protease complexes for SEM was attempted with colloids derived from the immunoperoxidase reaction, by the immunogold technique, and by antibodies linked to beads of synthetic polymers (polystyrene, polymethacrylate, polyacrolein). In addition, inactivated Staphylococcus aureus was used, which binds to antibodies through its protein-A. The high resolution by SEM of surface structures was matched only by the colloid based decoration techniques. All conjugates with beads suffered from inconsistent binding, which did not correspond with the distribution of the surface antigen. The comparatively best result with beads was obtained with polystyrene (Latex). Colloid based techniques in addition allow for critical point drying, which cannot be applied to synthetic beads in the usual manner.

Acrolein↗

PubMed1986

Canine atrioventricular node: scanning electron microscopy and enzyme histochemistry.

Morphologic features of the canine atrioventricular (AV) node were evaluated, using histochemical cholinesterase reactions and scanning electron microscopy. Three distinct regions of the AV node were observed: the transitional zone, superficial AV node, and deep AV node. The transitional zone lacked distinct cellular arrangement, and the cells were large and round with extensive branching on the ends. Superficial AV nodal cells were elongated, tightly packed, and smaller than were transitional cells. The superficial AV node was the densest zone of the AV node. Cell-to-cell contact was end-to-end. Deep AV nodal cells were long, formed laminated fascicles, were larger than the superficial AV nodal cells, and were continuous with the AV bundle.

Acetylcholinesterase↗

PubMed1985

[Hydrosalpinx and sterility. Value of studying tubal microbiopsies using scanning electron microscopy].

Microbiopsies were taken from the tubes of 13 women who were sterile with hydrosalpinges. They were studied using scanning electron microscopy. It was possible to point out several degrees in the evolution of these lesions of the tubal epithelium. These lesions occurred in the fimbrial portion, the ampulla and the isthmus of the tubes. The value of this investigation in diagnosis and prognosis in cases of sterility due to hydrosalpinx is discussed.

Biopsy↗

PubMed1983

Scope of scanning electron microscopy, transmission electron microscopy and freeze fracture technique in diagnostic cytology of effusions.

A review of the literature on the application of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to cytodiagnosis of neoplastic cells in effusion fluid reveals a lack of consensus as to which of the techniques is most beneficial to a cytologist for a satisfactory diagnosis. The purpose of this study is therefore to critically evaluate the relative merits of SEM, TEM and freeze-fracture (FF) techniques in enhancing the diagnostic "sensitivity" of ultrastructural cytology. Two cases of adenocarcinoma, one case of mesothelioma and one case of small cell undifferentiated carcinoma of the lung were studied in detail by SEM, TEM and FF techniques. A comparative analysis of the results demonstrates that SEM is a rapid and useful technique where the microvilli on the tumour cell surface is the most prominent feature especially in adenocarcinomas. The major handicap of SEM becomes evident in cases where the extreme variability of the surface morphology amongst tumour cells makes it difficult to establish a diagnosis with confidence. TEM along with light microscopy (LM) of toluidine blue sections gives us the most comprehensive method for cyto-diagnosis and is particularly useful in cases where LM cytology alone is inconclusive. It has the added advantage of revealing diagnostically significant nuclear and cytoplasmic features which are helpful in differentiating a benign from a malignant cell and in some instances the probable site of the primary neoplasm. FF technique, though not conducive to a routine diagnostic situation, is of benefit in demonstrating the organization of junctional complexes. From preliminary studies it appears that the tight junctions in adenocarcinoma are different from those seen in small cell carcinoma. In mesothelioma, gap junctions are invariably present, but they are not seen prominently in adenocarcinoma or small cell carcinoma. Thus in poorly differentiated tumours where LM and TEM are inconclusive, FF may prove useful. It is concluded that such coordinated studies in the future have the potential to better our understanding of the nature and behaviour of tumour cells in effusion fluid.

Adenocarcinoma↗

PubMed1984

[Morphology of the ampulla ductus deferentis of rabbits. Transmission and scanning electron microscopy studies].

The structure of the ampulla ductus deferentis of adult rabbits was studied by light-, transmission- and scanning-electron microscopy. The ampulla consists of a network of diverticles surrounding the central lumen. The diverticles are connected with each other and with the central lumen by oval or round openings. After ejaculation diverticles are usually empty. However, some diverticles were filled with spermatozoa only at sexual rest. The epithelial cells contain an abundant Golgi apparatus, which is organized as a system of closely packed flattened cisternae sometimes being in close connection to lipid droplets and lysosomes. The plasma membrane forms long microvilli-like processes and sometimes vesiculated spherical bodies, swollen cellular apices and protuberances apparently being pinched off.

Animals↗

PubMed1984

Coalescence of endothelial cells in the traumatized cornea. III. Correlation between specular and scanning electron microscopy.

Sequential specular microscopy has shown that coalescence of endothelial cells occurs after thawing in cryopreserved rabbit corneas. Scanning electron microscopy of corneas studied in vitro by specular microscopy showed the same large, fused endothelial cells. As observed in the electron micrographs, these cells showed no evidence of the cell borders that had disappeared during the specular microscopic examination. These data support the reliability of our specular microscopic observations and provide additional evidence for the occurrence of fusion or coalescence of corneal endothelial cells.

Animals↗

PubMedDate not supplied

Quantitative scanning electron microscopy for the evaluation of thrombosis in extracorporeal circuits.

Methods devised in the past to evaluate blood-material interactions in extracorporeal devices assess small segments of test materials and do not analyze the entire circuit. In order to develop an effective method for the control of thrombosis in extracorporeal circulation, it is important to perform a quantitative evaluation of random samples of all the circuit elements. In an effort to quantify thrombosis in experimental extracorporeal membrane oxygenation circuits, random samples of silicone rubber membrane and polyvinyl chloride tubing were examined using scanning electron microscopy (SEM) and quantitative morphometry. The results indicate no statistically significant differences in the amounts of various adhered blood components between the tubing and the membrane. Greater than 60% of the examined surface had no blood components present. Platelet adhesion on the surface was predominant. Evidence of fibrin, gross thrombi, red cells, and white cells in small quantities were noted. It is concluded that quantitative scanning electron microscopy (QSEM) not only provides accurate information about the morphologic changes of blood cells due to surface contact, but also quantifies the individual elements and therefore assesses their contributions to thrombosis. This quantitative description will allow more meaningful comparison of blood-compatible materials and surfaces.

Animals↗

PubMed1982

Iron carbonyl, a tracer for phagocytosis in scanning electron microscopy.

Human peripheral blood mononuclear cells and polymorphonuclear (PMN) leukocytes, separated by Ficoll-Hypaque have been incubated with a preparation containing iron carbonyl, and studied by scanning electron microscopy (SEM) in the backscattered electron imaging (BEI) mode. Iron carbonyl particles were visible only on the cell surface when studied in the conventional secondary electron (SE) mode of the scanning electron microscope. However, ingested iron carbonyl particles were observed in high contrast when the backscattered electrons were selectively collected. The BEI mode of the scanning electron microscope appeared very useful in identifying phagocytic activity in mixed cell populations and in establishing direct correlations, at the level of each individual cell, between surface morphology and phagocytic activity.

Humans↗

PubMed1996

Demonstration of the fine structure of stereocilia in the organ of Corti of the guinea pig by field emission scanning electron microscopy.

A combined perfusion- and immersion prefixation with glutaraldehyde followed by a tannic acid/arginine/osmium tetroxide (TAO) treatment of the guinea pig cochlea is described for field-emission gun scanning electron microscopy (FEG-SEM) observation of the fine structure of the stereocilia of the organ of Corti. Conventional osmium tetroxide postfixation methods in combination with a thin conductive coating failed to show the fine structure of the glycocalyx of the epithelial lining in the endolymphatic compartment of the cochlea, in particular, on the stereocilia surface. The antennulae-like glycocalyx covering of the stereocilia surface of the more pronounced rows of outer hair cells has been demonstrated only in ultrathin sections by means of cationic markers. The side- and tip-links connecting the stereocilia have been demonstrated both in scanning and transmission electron microscopy, although at that time these structures often were considered as artificial. However, they can be visualized with FEG-SEM at low accelerating voltage (2-3 kV), and at appropriate working distance and probe current, in combination with a glutaraldehyde perfusion/immersion prefixation and TAO postfixation. Stereo images enhance considerably the three-dimensional appreciation of the stereocilia with glycocalyx lining and side- and tip-links, proving that these connections are a structural part of the hair cell.

Animals↗

PubMed1975

Scanning electron microscopy of the wall of the third ventricle of the brain of Rana temporia. II. Electron microscopy of the ventricular surface of the pars ventralis of the tuber cinereum.

Scanning electrom microscopy of the ventricular surface of the pars ventralis of the tuber cinereum of the frog Rana temporaria shows that it can be divided in (1) a dorsolateral area, characterized by the presence of very numerous large, solid, bulbous protrusions (2) a medial area, where the large bulbous structures are completely absent and which is diffusely covered with very numerous cilia, (3) a transiotional area located between the two other regions. The large bulbs, shown by scanning electron microscopy, correspond with the end-bulbs of thick ventricular dendrites of nerve cells revealed by transmission electron microscopy. At least many of these intra-ventricular bulbs are dendritic endings of peptidergic neurosecretory neurons, which have been tentatively identified as adenohypophysiotropic neuro-hormone producing neurons (Derickx et al., 1972, 1973a, 1973b). The structural features of the dendritic endings plead in favour of a possible receptive role.

Animals↗

PubMedDate not supplied

Uncombable hair (cheveux incoiffables, pili trianguli et canaliculi) syndrome: brief review and role of scanning electron microscopy in diagnosis.

Uncombable hair syndrome was first described some 3 decades ago as "cheveux incoiffables" and is also known as spun-glass hair and pili trianguli et canaliculi. Both inherited (autosomal dominant and recessive with variable levels of penetrance) and sporadic forms of uncombable hair syndrome have been described, both being characterized by scalp hair that is impossible to comb due to the haphazard arrangement of the hair bundles. A characteristic morphologic feature of hair in this syndrome is a triangular to reniform to heart shape on cross-sections, and a groove, canal or flattening along the entire length of the hair in at least 50% of hairs examined by scanning electron microscopy. Most individuals are affected early in childhood and the hair takes on a spun-glass appearance with the hair becoming dry, curly, glossy, lighter in color, and progressively uncombable. Only the scalp hair is affected. Several conditions are associated with uncombable hair, such as ectodermal dysplasia, retinal dysplasia/pigmentary dystrophy, juvenile cataract, digit abnormalities, tooth enamel anomalies, oligodontia, and phalangoepiphyseal dysplasia. Other syndromes with hair abnormalities may also mimic uncombable hair syndrome clinically and these include, Rapp-Hodgkin ectodermal dysplasia; loose anagen hair syndrome; ectodermal dysplasia, ectrodatyly, cleft lip/palate (EEC) syndrome; and familial tricho-odonto-onchyial ectodermal dysplasia with syndactyly. Unlike other conditions with an uncombable hair component, uncombable hair syndrome alone (cheveux incoiffables, pili trianguli et canaliculi) is not associated with physical, neurologic, or mental abnormalities. In most cases of uncombable hair syndrome, the hair is grossly abnormal in infancy and early childhood, but may have improved manageability later in life. Scanning electron microscopy of hair samples provides definitive evidence for diagnosis of clinically suspected uncombable hair syndrome and eliminates other hair abnormalities from the differential diagnosis.

Chemical Phenomena↗

PubMed1997

[Fornicate structure of blind saccular lymph vessel segments in the conjunctiva--scanning electron microscopy studies].

BACKGROUND: The accepted fundamental element of the initial lymphatic system is a tubular structure (lymphatic capillary), which is present either in the form of a finger-shaped blind-ending protuberance, or in the nature of a plexiform composite arrangement. We were able to demonstrate experimentally that the finger-shaped protuberances, which are known as "initial segments" are in fact temporary filling states. As the filling process continues, these vascular elements become intermediate segments, via which other parts of the vascular network take up the dye. To date there have been no investigations of the internal structure of these apparently blind-ending vessel segments. In this study, lymphographically represented "terminal segments" should be cut away for the purpose of examining the fornix by scanning electron microscopy. Is the internal surface of the fornix regular and unbroken, or are there fissure-like structures which could explain the observed filling processes? MATERIAL AND METHODS: In conjunctiva of bovine eyes (n = 80), interstitial double-contrast lymphography (Berlinblue solution/air) under a slit-lamp microscope was used specifically to search for finger-shaped terminal segments. The conjunctivae had previously been prepared by fixing in polymeric resins. A proportion (n = 21) of the specimens were amenable to examination under the scanning electron microscope. RESULTS: Notwithstanding the observed great variation in the shape of the lymphographically obtained blind-ending structures-in the form of terminations shaped variously like fingers, balloons, domes, pistons or pyramids, terminations with two humps, and terminations shaped like spear heads-scanning electron microscopy revealed within the fornices many relatively uniformly shaped structures in the form of fissures, configured with lips and saw-tooth edges, rather like zip fasteners. These findings are suggestive of preformed connections to neighbouring segments. This appears to be another element, in addition to the familiar flap-like structures, for controlling the circulation of lymph. Does the "initial part" of the lymphatic system now have to be redefined?

Animals↗

PubMedDate not supplied

Detection of calcifications in breast biopsies by scanning electron microscopy.

The identification of microcalcifications in breast biopsy specimens is a common and important task for the surgical pathologist that may sometimes be problematic. Although visualized by preoperative mammographic and operative specimen radiography, some cases may fail to reveal calcifications by histopathologic examination or occasion laborious and time-consuming study to confirm sparse calcifications. The present study demonstrates how conventional bright-field and polariscopic light microscopy did require considerable effort to confirm rare calcification. On the other hand, scanning electron microscopy was employed directly on a routine slide and provided definitive visual and physical proof, e.g., by means of energy dispersive x-ray microanalysis of a rare calcification on a slide previously judged to be negative for calcium and in a short period of time. Recent instrument advances in high voltage beam stabilization and in the ability to vary the pressure of the scanning electron microscope in the vicinity of the specimen now allow complete insertion of a diagnostic glass slide with only trivial preparation. The report, although brief, raises important questions regarding the extent and prevalence of breast calcifications.

Adult↗

PubMedDate not supplied

[Scanning electronic microscopy of the small intestine in persistent diarrhea].

Persistent diarrhea very often leads children to malnutrition. It has become the major cause of death resulting from acute diarrhea episodes in developing countries. In order to determine the ultrastructural alterations of the small bowel that occur in the syndrome, 16 infants with severe persistent diarrhea were studied, utilizing light microscopy and the scanning electron microscope. Stool and jejunal fluid samples were collected for culture, rotavirus, ova and parasite search. Enteropathogenic agents were isolated in stools from 11 (68.7%) patients and bacterial proliferation in the small bowel was detected in 11 (68.7%) patients. EPEC strains were the most frequent enteropathogenic agent isolated both from stool and jejunal fluid cultures. The stool cultures revealed the presence of the following enteropathogenic microorganisms: EPEC 0111 in four, EPEC 0119 in one, EAggEC in five, Shigella flexneri in two, and Shigella sonnei in one; mixed infections due to EAggEC associated with EPEC 0111 were seen in two patients. The light microscopic analysis revealed that 56.2% of the patients suffered moderate villous atrophy most frequently associated with effacement of the microvilli, intracytoplasmatic vacuolization, increased number of multivesicular bodied and increased lymphocytic and eosinophylic infiltration in the lamina propria. The scanning electron microscopic analysis revealed in all cases shortening of the villi and enterocyte derangements; very often there was a total lack and/or effacement of the microvilli; in half of the patients there was a mucoid material covering the enterocytes tightly adhered to the apical epithelium surface. The scanning ultrastructural alterations observed in these patients are probably due to an association of factors brought about by the presence of enteropathogenic microorganisms and the resulting food intolerance that is responsible for perpetuation of diarrhea.

Diarrhea, Infantile↗

PubMed1996

Problems in preparation of chromosomes for scanning electron microscopy to reveal morphology and to permit immunocytochemistry of sensitive antigens.

Although much information about chromosome structure and behaviour has been obtained using light microscopy, greater resolution is needed for a thorough understanding of chromosome organisation. Scanning electron microscopy (SEM) can provide valuable data about these three-dimensional organelles. The introduction of methods using osmium impregnation of methanol-acetic acid-fixed chromosome spreads revolutionised matters, producing life-like images of chromosomes. Nevertheless, it became clear that osmium impregnation introduced various artefacts, although the resulting images were still useful. Methanol-acetic acid-fixed chromosomes are, in fact, flattened on the glass substratum, and the 3-dimensional appearance obtained after osmium impregnation is the result of swelling during this process. At the same time, the fibrous substructure of the chromosomes becomes much coarser. More recently a number of alternative methods have become available for studying chromosomes by SEM. Isolated chromosomes, that have not been allowed to dry during preparation, retain a 3-dimensional appearance without osmium impregnation, and the same is true of methanol-acetic acid-fixed chromosomes that have been treated with 45% acetic acid and processed without drying; however, these methods do not permit the routine production of intact metaphase spreads. Use of cytocentrifuge preparations obviates the use of acetic acid fixation and osmium impregnation, produces intact metaphase spreads, and permits the immunocytochemical detection of antigens that are easily destroyed by routine fixation procedures.

Acetic Acid↗