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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↗
PubMed1996

The three-dimensional architecture of the myosalpinx in the rat (Rattus norvegicus) as revealed by scanning electron microscopy.

The three-dimensional (3-D) architecture of myosalpinx in the rat has been investigated by means of scanning electron microscopy after microdissection and removing interstitial connective tissue with 6N NaOH digestion. In the extramural portion of tube-uterine junction the myosalpinx shows circularly arranged fibers originating from the uterus, together with oblique fibers typical for the salpinx, which occur more frequently in the deeper layers. As fibers approach the mucous folds they assume a plexiform arrangement, which is maintained through all tubal segments. In the isthmus surface fibers form wide muscle rings around the elbow of loops, peculiar to the rat tubal morphology. Surface fibers in the ampulla and pre-ampulla have an even circular course. Our 3-D results reveal that the muscular architecture of rat tube is mainly organized in concentric, monolayered shells with a plexiform arrangement tightly fastened together. Functionally, this muscular arrangement seems to be capable of stirring rather than pushing the embryo and gametes. Finally, such a plexiform network might work as a mechanism of "tube locking" in proximity of isthmic loops as well as at the level of the ampullary-isthmic junction.

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↗
PubMed1980

Scanning electron microscopy of oral lesions in chronic mucocutaneous candidiasis.

The oral surfaces of 12 patients with chronic mucocutaneous candidiasis were studied by scanning electron microscopy (SEM). Candida albicans in massive numbers populated the surface of the infected mouth of each patient. Although pseudohyphae were the predominant forms, blastospores and chlamydospores were also found. Pseudohyphae penetrated the epithelium and seemed to enter through holes in the keratinized cells. Because specimen processing for SEM can be completed within six hours, the scanning electron microscope can be used to identify C albicans more rapidly than culture methods.

Acid Phosphatase↗
PubMed1981

Use of multiparameter studies and scanning electron microscopy in the interpretation and attempted correlation of surface morphology with cell type in 135 cases of human leukemias.

Multiparameter studies and scanning electron microscopy (SEM) were performed on cells obtained from 135 cases of leukemia in an attempt to clarify whether there was a reliable correlation between surface morphology and cell type as defined by cytochemistry, membrane markers, and transmission electron microscopy. These studies also attempted to determine whether SEM could be used to distinguish lymphoid and nonlymphoid leukemias, to recognize different types of lymphoid leukemia, and to define the cell type involved in cases of unclassified leukemia. The results of this study suggest that there is a good correlation between surface morphology as seen by SEM and cell type identified by multiparameter techniques. In most cases, nonlymphoid leukemic cells could be distinguished from lymphoid leukemic cells on the basis of their surface morphology. SEM did not appear to contribute to the diagnosis of unclassified leukemia, but more cases of this nature must be studied. Despite the fact that acute lymphoblastic leukemia cells frequently showed fewer microvilli than did other lymphoid leukemias, overlap of surface features in about one-third of the cases did not enable SEM to be used as a reliable means of distinction. The above conclusions appear to be supported by preliminary scanning immunoelectron microscopic observations on leukemic cells. It is concluded that SEM is a useful aid to other modes of microscopy in leukemia but should not be used on its own to establish diagnosis.

Cell Membrane↗
PubMed1991

Muscle spindle ultrastructure revealed by conventional and high-resolution scanning electron microscopy.

Muscle spindles in the tenuissimus muscle of mature golden Syrian hamsters were examined by conventional and high-resolution scanning electron microscopy (HRSEM). For conventional SEM, entire muscles were first fixed in 2.5% buffered glutaraldehyde. Spindles were then isolated with a dissecting microscope under darkfield illumination and postfixed in 1.0% OsO4. Some spindles were treated with 8 N HCl at 60 degrees C to clearly expose intrafusal fiber surfaces once the outer capsular sheath was mechanically disrupted. Preparation for HRSEM included aldehyde/osmium fixation and freeze-cleavage in liquid N2. The cytosol and certain cellular elements were also selectively extracted by immersion in 0.1% OsO4 for varying time intervals. In these preparations, the capsular sleeve showed a multilayered pattern of vesicle-laden cells with variant surface topography in different regions, including filopodia and small bristle-like surface-projections. An interlacing three-dimensional network of collagen fibrils intervened between the capsular lamellae. Within the spindles, sensory and fusimotor nerve endings closely adhered to the outer surfaces of intrafusal fibers. Sensory nerve terminals were enveloped by a prominent external lamina, and those that were cleaved open contained a plethora of elongated mitochondria that ran parallel with the longitudinal axis, along with vesicles, axoplasmic filaments, and lysosomes. Multiple adhesion sites between the sensory nerve membrane and the underlying sarcolemma of the intrafusal fiber were also observed in select regions. Fusimotor nerve endings were covered externally by processes of Schwann cells and their axoplasm was filled with a multitude of cellular organelles and synaptic vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1975

Surface morphology of murine B and T lymphocytes: A comparative study by scanning electron microscopy.

A variety of murine lymphocytes of known B or T derivation obtained from different lymphoid organs were prepared for scanning electron microscopy (SEM) by the critical point drying method after collecting the cells by aspiration onto silver membranes. Comparison of SEM appearances of cells prepared by this technique and serological classification according to surface antigens showed that most T cells had smooth surfaces with few microvilli, while many B lymphocytes were moderately to markedly villous. Further evidence for the above correlation was obtained by examining thymic cells and enriched B or T cell populations. Thymic cell suspensions containing less than 5% B cells showed over 80% generally smooth cells by SEM. Enriched T cell populations, obtained by mass cytolysis of lymph node preparations with anti-Ia or anti-Ig sera or by purification through nylon fiber columns, contained over 85% T cells, and more than 75% of them were of the smooth cell type. A similar correlation was noted for enriched B cell populations obtained by cytolysis of lymph node cells with anti-Thy-1 serum, and by lysis of EAC-rosettes. Over 90% of these cells were identified as B cells by immunologic methods and approximately 75% had moderate to markedly villous surfaces. The 15% difference can be accounted for by the existence of a subpopulation of smooth B cells. Direct observation of EAC-rosettes confirmed that most B cells had moderate to large numbers of surface microvilli and that less than 10% were smooth. It is possible that some of the smooth cells seen in enriched B cell populations may represent precursors or B lymphocytes at different stages of differentiation. These results indicate that murine T and B lymphocytes, like their human counterparts, can be recognized in many cases under the SEM on the basis of their surface morphology. Smoother B and more villous T cells are difficult to classify by SEM without parallel immunologic identification.

Animals↗
PubMed1984

Scanning electron microscopy on Microsporum audouini complex.

Several strains of Microsporum audouini, M. langeroni and M. rivalieri were observed by light and scanning electron microscopies. The macroaleuriospore shape and ornamentation were illustrated and compared for the 3 species as the pectinate hyphae for M. langeroni and M. rivalieri and the chlamydospores and particular hyphae for M. audouini and M. langeroni. The 3 species are morphologically very close but they are distinguishable from each other on the basis of morphology, geographic distribution and pathogenicity.

Dermatomycoses↗
PubMed1978

Scanning electron microscopy (s.e.m.) of biopsy specimens of ruptured intracranial saccular aneurysms.

Surgical specimens of 4 intracranial saccular aneurysms were studied by scanning electron microscopy. The internal surface of the aneurysms showed crater-like defects and cytoplasmic bridges. In some areas the endothelium was preserved, but its longitudinal convolutions were higher and thicker than those found in unchanged areas. On the damaged endothelial surface there was an increased number of blood cells. The adventitia resembled that of a normal cerebral artery. In conclusion the alterations observed are similar to those found in atherosclerosis and are most likely due to the high wear and tear provoked by the blood streaming into the aneurysm. The results of this study are in agreement with the findings of a companion transmission electron microscopy study and emphasize the importance of degenerative changes on the development and rupture of intracranial saccular aneurysms.

Adult↗
PubMed1986

Neovascularization in the splenic autograft transplanted into rat omentum as studied by scanning electron microscopy of vascular casts.

Neovascularization during regenerating process in splenic tissue autotransplanted into rat omentum was studied by means of scanning electron microscopy of vascular casts. The results obtained indicated that neovascularization is classified into the following four steps; capillarization in the connective tissue surrounding the degenerating autograft, connection of blood vessels between the still surviving splenic cords and capillaries in the surrounding tissue, rebuilding of the splenic sinuses and remodelling of regenerated blood vessels. This neovascularization process is specific in that the preexisting splenic cords play an important role in angiogenesis during regenerative process in the autograft.

Animals↗
PubMed1983

The thermic vascular anastomosis (TVA). IV. Analysis by scanning electron microscopy.

In the present study 48 thermic vascular anastomoses performed in Sprague Dawley Wistar rats were subjected to analysis by scanning electron microscopy. Depending on the period of postoperative survival (up to 18 months) normal smooth endothelium, dissected cuffs and aneurysms were seen. Endothelial damage through heat application following bipolar coagulation was only slight. In one 18 months old anastomosis an aneurysm with a delicate network of endothelialized filaments was seen leaving a free passage for the blood flow centrally. A comparison of the literature describing the healing processes of intima following various traumas is made.

Animals↗
PubMed1986

Fetal microcirculation of abnormal human placenta. I. Scanning electron microscopy of placental vascular casts from small for gestational age fetus.

The latex injection-corrosion cast technique coupled with scanning electron microscopy was applied to the study of small for gestational age placentas. The main ultrastructural changes observed in the fetal vasculature of small for gestational age placentas were less branching of arteries and veins, capillaries with variable diameters, and many capillary bud projections; also numerous "H"-shaped anastomoses were present in the capillary network. The corrosion/cast technique approach enabled us to visualize the three-dimensional distribution of arteries, veins, and capillary network as well as the ultrastructural alterations among the various-sized vessels in the abnormal placenta. Light microscopic examination of these placentas revealed numerous syncytial knots and fibrinoid deposits pressing on arteriolar and capillary vessels at different locations. We suggest that the numerous capillary buds and anastomoses are characteristics of neovascularization and may be a compensatory phenomenon of the capillary network. This information could shed new light on alterations of physiologic functions of the pathologic placenta.

Adult↗
PubMed1986

Fetal microcirculation of abnormal human placenta. II. Scanning electron microscopy of placental vascular casts from fetus with severe erythroblastosis fetalis.

The latex injection-corrosion cast technique coupled with scanning electron microscopy was applied to the study of severe Rh sensitization of the placenta. The main observed ultrastructural changes in fetal vasculature in this type of placenta were very similar to those of the small for gestational age placenta; large-sized vessels exhibited less branching than those of the normal placenta, and the capillary network showed numerous vascular buds and "H"-shaped anastomoses. In addition, in Rh-sensitized placentas, the capillary network was remarkably sparse, and the cast also revealed smooth-surfaced veins with distinct U shapes undulating through the placental stroma. These U-shaped veins may be the result of umbilical flow impedance with subsequent umbilical venous hypertension, which stretches the veins into undulating form.

Adult↗
PubMed1976

Scanning electron microscopy of repaired tendon and pseudosheath.

(1) Repairing surface structure of transected digital flexor tendons of hens were studied by scanning electron microscopy. One week after a simple suture, fibrous materials probably of fibrin and exudated blood cells were attached on the surface. After two weeks, lining cells enmeshed with fine fibrils covered most of the surface. After three weeks, cellular protrusions of spindle shape spread over the repaired tendon. (2) Repaired surface of partially resected tendons of hens showed the same sort of healing processes as observed in the sutured tendons. The injured tendon surface was covered with the lining cells derived from surrounding synovium. (3) It was suggested that the repair of the injured tendons may occur from the surrounding tenosynovium, where the fibroplastic-like lining cells cover the injured part. (4) Observation of surface structure of pseudosheath was carried out after the silicone rod implantation with complete resection of the surrounding sheath. In one or two weeks, spindle-like cells probably corresponding to fibroblasts appeared on the surface. Fibrillar substance also mingled with such fibroblastic cell protrusions. Well-repaired pseudosheath similar to the normal parietal sheath was seen at four weeks. Such differentiated synovial lining cells formed from the peritendinous tissues were also regenerated from the original area around this time. (5) It could be said that the experimental repair on the visceral and parietal layer of the tendon sheath was similar in time and form. However, it seems to be necessary to compare the results from human subjects in relation to the abnormal repair of the injured tendon such as in adhesions.

Animals↗
PubMed1994

Pathobiology of articular cartilage in trapeziometacarpal osteoarthritis. II. Surface ultrastructure by scanning electron microscopy.

Regional variation in the surface ultrastructure of hyaline cartilage in the osteoarthritic trapeziometacarpal joint was studied by means of scanning electron microscopy. Articular surface degeneration on intact osteochondral specimens was analyzed and correlated with known patterns of gross, histologic, and biochemical disease. The earliest changes were observed in the tangential surface lamina and occurred in areas of chondromalacia in the palmar contact area of the joint. Progressive disruption of this superficial fibrillar layer of the articular cartilage was followed by disorganization of the underlying chondrocytes and matrix. In palmar regions with more advanced chondromalacia and loss of eosinophilic staining, free cellular elements and craters 20-30 microns in diameter, resembling empty chondrocyte lacunae, appeared in conjunction with the absence of any tangential surface meshwork. Eburnated areas demonstrated no fibrillar or cellular elements. Disruption of the protective surface lamina of trapeziometacarpal articular cartilage occurs in a geographic pattern corresponding to joint contact areas and regions of selective biochemical decomposition of proteoglycan matrix. These observations support an interdependent relationship between mechanically induced abrasive surface wear and biochemical matrix degradation in the production of the cartilage lesion of trapeziometacarpal osteoarthritis.

Adult↗
PubMed1989

A new view of the arterial smooth muscle cells and autonomic nerve plexus by scanning electron microscopy in spontaneously hypertensive rats.

Mesenteric artery smooth muscle cells and their associated autonomic nerve plexus were simultaneously studied by scanning electron microscopy in 3-month-old spontaneously hypertensive rats. The adventitial surface of the outermost muscle layer revealed numerically more protrusions accompanied by a denser network of nerve fibers in spontaneously hypertensive rats vs normotensive Wistar-Kyoto rats.

Animals↗