Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The extensor digitorum longus muscles of 4-6-week-old normal mice (129 ReJ) and dystrophic mice (129 ReJ dy/dy) were orthotopically transplanted. Grafted muscles were examined 1, 3, 7, 14, 20, 50, and 100 days post-transplantation. The myofibers of both types of grafts underwent a similar time course of necrosis and regeneration. Other than during the initial necrotic response, no evidence of necrotic myofibers was found in either type of grafted muscle. At 100 days post-transplantation, the grafted normal and dystrophic muscles were essentially similar, except that the dystrophic graft was of smaller size. Based on a comparison of the number of myofibers found at the 100-day grafts' widest girths [631 +/- 59 SEM, for normal grafts (Bourke and Ontell, 1984); 631 +/- 74 SEM, for dystrophic grafts], it is suggested that the regenerative capability of traumatized 4-6-week-old dystrophic muscle is similar to that of traumatized normal muscle. At 100 days post-transplantation, the grafted dystrophic muscle appeared "healthier" than untraumatized muscle from age-matched dystrophic mice, having less variation in myofiber diameter, better fascicular organization, and less connective tissue. The transplantation system demonstrates the possibility of modifying the expression of genetic programming of myopathic disorders using environmental manipulation.
Anat Rec 1986 Jan
PMID:Modification of the phenotypic expression of murine dystrophy: a morphological study. 395 56

At the muscle-tendon junction of skeletal muscle fibers the structural interface between muscle cell and connective tissue is amplified by tapering, by indentation, and by surface folding. The precise form taken by the surface folds has been unknown due to a lack of studies on the three-dimensional geometry of the muscle-tendon junction. Analysis of this region by scanning electron microscopy, using conventional preparative techniques, is uninformative because the muscle surface is covered by connective tissue. Removal of the connective tissue from individual murine muscle fibers by incubation of fixed fibers in hot HCl, followed in some instances by treatment with collagenase, permits SEM analysis of the uncovered fiber ends. The muscle fiber end is characterized by surface specializations in the form of anastamotic cylindrical folds. Transmission electron micrographs of cross sections and of serial longitudinal sections of muscle fiber ends confirm that the SEM observations are correct.
Anat Rec 1985 Sep
PMID:Three-dimensional structure of the murine muscle-tendon junction. 407 57

The degree of metachromasia of mast cell granules is known to vary with the type of tissue fixation and among different tissues and species. The present study sought to determine whether mast cells in dog skin are heterogeneous with respect to fixation and staining properties. We performed skin biopsies in six anesthetized, atopic dogs and one mongrel dog. One biopsy was fixed in formalin and a second, from a parallel abdominal site, was fixed in basic lead acetate (Mota's solution). Adjacent sections from each biopsy were stained with alcian blue (1%, pH 0.5) or for chloroacetate esterase activity. In alcian blue-stained sections, one-third fewer mast cells were detected in skin fixed in formalin (1,836 +/- 454 mast cells/mm3, mean +/- SEM) than in skin fixed in basic lead acetate (2,684 +/- 527 mast cells/mm3) (P less than 0.05). The chloroacetate esterase reaction detected the larger number of mast cells regardless of the fixative used. We conclude that mast cell heterogeneity, as demonstrated by metachromatic staining following different types of tissue fixation, exists in dog skin. "Typical" mast cells stain with alcian blue regardless of fixation; however, "atypical" mast cells exhibit metachromasia only after fixation in basic lead acetate. Both the typical and atypical types of mast cells have chloroacetate esterase activity.
Anat Rec 1985 Dec
PMID:Mast cell heterogeneity in dog skin. 408 28

Ruthenium red (RR) and cetylpyridinium chloride (CPC) were used to demonstrate the distribution of cell surface coat material (SCM) on the free epithelial surface of the developing lens vesicle in stages 14-17 (50-64 hours) chick embryos. Observations were made by light microscopy and transmission. (TEM) and scanning (SEM) electron microscopy. A progressive increase in SCM is observed on cellular apices within the epithelium of the lens vesicle by means of RR staining, particularly at the margins of the aperture which are the sites of presumptive fusion. In contrast, a relatively thin layer of SCM persist on the adjacent surface ectoderm. Ruthenium red-positive SCM extends across the aperture of the lens vesicle prior to initial contact between the advancing epithelial surfaces. The presence of abundant SCM is interpreted as a possible significant prerequisite to invagination and to epithelial adhesion and fusion prior to detachment of the lens from surface ectoderm. When CPC is added to the fixative, a flocculent precipitate over the aperture of the lens vesicle and an associated band of modified surface ectoderm which extends ventrally from its lower margin are observed. The modified ectoderm and associated SCM likely represent a presumptive region of active coordinated cellular migration.
Anat Rec 1981 Oct
PMID:Surface coat material associated with the cells of the developing lens vesicle in the chick embryo. 617 59

Ovarian morphology and behavioral relationships were studied in a group of nine miniature pigs with a characteristically small litter size (-5) and an average coefficient of inbreeding of 0.39. The first day of standing estrus was designed as day 0, Laparoscopy was used to evaluate and photograph ovarian activity on days 1, 5, 11, 17, and day 2 of the subsequent estrous cycle. Mean (+/-SEM) duration of estrus and the estrous cycle was 3.1 +/- 0.2 and 22.6 +/- 0.3 days, respectively. An average of 9.0 +/- 0.4 vesicular follicles developed/estrous period and 96% of the follicles showed morphologic evidence of ovulation resulting in a mean of 8.6 +/- 0.3 corpora lutea (CL) per animal. There was no significant correlation between the degree of inbreeding and number of vesicular follicles (r = 0.27) or CL (r = 0.28) developing/cycle within the experimental group. Mature preovulatory follicle and CL size ranged from 6-12 mm and 8-12 mm in diameter, respectively, and 22.5% of the newly formed CL contained distinct postovulatory stigmata. These data indicated that 1) temporal relationships of sexual behavior and gross ovarian morphology in the miniature pig were similar to descriptions previously reported for the standard pig, and 2) the reduced litter sized characteristic to this particular strain is, at least in part, due to decreased number of vesicular follicles developing during the estrous cycle.
Anat Rec 1982 May
PMID:Correlates of ovarian morphology, estrous behavior, and cyclicity in an inbred strain of miniature swine. 621 80

We describe the SEM appearance of the rat endosteal bone lining cell ( BLC ) population, and the sequence of morphological changes of these cells as they self-incorporate into unmineralized bone matrix (osteoid), establish intercellular connections, and construct lacunae. The osteoblast/nascent osteocyte series was progressively unsheathed by gentle digestion of the osteoid with 0.25% collagenase. The osteoblasts which leave the polygonally packed BLC compartment rapidly develop numerous complexly branched processes that contact the processes elaborated by previous generations of maturing and mature osteocytes. As osteoblasts mature and approach the mineralization front, they appear to lose processes. The mature cells begin to form osteocyte lacunae by depositing an asymmetric perimeter of woven collagen fibrils, such that as the cells roof-over, the lacunae appear as pocketlike constructions. The collagen fibrils on the perilacunar matrix are oriented in a tangential or circular pattern, while those in the more distal matrix are arranged in a parallel pattern. With the completion of a lacuna, its wall appears to mineralize quickly, for lacunae could be recognized only when they are forming.
Anat Rec 1984 May
PMID:From bone lining cell to osteocyte--an SEM study. 632 38

The extent of the odontoblast cell process has been the subject of controversy for many years. Using SEM we have examined the extent and morphology of the process on dentine surfaces of human teeth which were partially demineralized and collagenase digested. Third molars were extracted and split; the dentine surface was demineralized, digested by bacterial collagenase, fixed with glutaraldehyde, postfixed in osmium tetroxide, and prepared for SEM investigation. The SEM study revealed the presence of many processlike structures which extended from the odontoblast cell bodies up to the dentinoenamel junction (DEJ). These processes demonstrated lateral and terminal branching and some of them terminated in distended spheres. We have also applied an immunofluorescence technique at the light microscope level to these exposed dentinal surfaces to localize the intracellular microtubules. For this, a second series of third molars was processed in the same manner as for the SEM up to the fixation stage. Teeth were then fixed in periodate-lysine-paraformaldehyde, postfixed in -20 degrees C acetone, and then incubated with affinity-purified rabbit antitubulin antibodies, followed by fluorescein-conjugated goat antirabbit IgGs. Intratubular immunofluorescence labelling for tubulin was evident from the odontoblast cell bodies up to the DEJ. The presence of the tubulin-containing structures extending to the DEJ supports the hypothesis that the structures observed with the SEM are odontoblast processes and that the odontoblast processes do extend to the DEJ.
Anat Rec 1984 Nov
PMID:A combined scanning electron microscopy and immunofluorescence study demonstrating that the odontoblast process extends to the dentinoenamel junction in human teeth. 639 20

Orthotopic transplants of whole extensor digitorum longus muscles were performed on six 4-6-week-old 129 ReJ mice. One hundred days posttransplantation, the animals were killed and the regenerated muscles were processed for electron microscopy. The grafts contained polygonal-shaped myofibers with persistent central nuclei, organized into discrete muscle fascicles. No central area of fatty infiltration or fibrosis was observed. The mean number of myofibers in a regenerating transplanted muscle, as determined from an ultrathin section taken from the graft's widest girth, was 631 (SEM = +/- 59), a reduction of approximately 32% from that found in age-matched control muscle (Ontell et al., 1983). By following the myofibers in spaced, serial ultrathin sections along their length, it was found that the branched, regenerating myofibers found in immature grafts of normal muscle (Ontell et al., 1982) persisted in stabilized, long-term transplanted muscle. The frequency of branching was determined by following each fiber found at the widest girths of four of the grafts in spaced, serial ultrathin sections (15-micron intervals) for approximately 2% of the total length of the grafts. Over this distance, 6.6% of the fibers were involved in the branching phenomenon. The persistence of branched fibers in long-term grafts and the frequency with which the branching phenomenon was found to occur may have physiological consequences and should be investigated.
Anat Rec 1984 Jul
PMID:Branched myofibers in long-term whole muscle transplants: a quantitative study. 646 37

The developing inner ear of the teleost, Brachydanio rerio, provides an opportunity for observing an epithelial fusion between the apical surfaces of apposed epithelia in a vertebrate embryo in vivo. The developing otocyst was filmed for periods up to 4 days in unanesthetized embryos, and specimens were fixed at intervals and processed for light microscopy, TEM, and SEM. The semicircular canals are formed as a consequence of the union between the tips of three cylindrical projections from the wall of the otocyst, which grow toward corresponding bulges of a projection from the lateral wall. The epithelial cells covering the projections contain extensive rough endopasmic reticulum, exhibit apical junctional complexes, and are not underlain by a basal lamina. The core of each projection contains large amounts of flocculent and fibrillar extracellular material. After a period of growth and elongation, the tip of each projection contacts, and adheres to, the appropriate bulge to create a circular, flattened, bilayered, epithelial plate. Small, focal junctions form between the apposed apical cell surfaces within the plate during this period, but they are not numerous. Junctional complexes do develop, however, between apposed cells at the periphery of the plate. After 1-2 hours, the basal surface of the plate exhibit considerable alteration in contour. Adjacent cells within the plate then separate to allow continuity of the connective tissue components of the two structures. The observations of this study indicate that following an initial period of contact and adhesion, cellular reorientation and changes in junctional contacts between adjacent cells within the epithelial plate, rather than cell degeneration, are responsible for perforation of the plate.
Anat Rec 1984 Sep
PMID:Epithelial fusion during early semicircular canal formation in the embryonic zebrafish, Brachydanio rerio. 648 77

Incubation of skin in 2 N sodium bromide allows separation of dermal and epidermal layers leaving an intact basal lamina covering the dermal portion. Examination of the surface of the dermis by SEM shows cells migrating through the basal lamina. By scanning and transmission electron microscopy, these cells have the characteristics of lymphocytes. The migrating lymphocytes produce a sequence of basal lamina deformations including dome formation, effacement of corrugations, and central fenestrations with hole formation allowing lymphocyte passage. Following passage there is reestablishment of a relatively smooth basal lamina in the crater base, effacement of the crater rim, and finally reformation of basal lamina corrugations. This deformability of the basal lamina supports the hypothesis that basal lamina is thixotropic. This study is the first demonstration in three dimensions of lymphocyte traffic across the basal lamina, an important component of skin-associated lymphoid tissue (SALT).
Anat Rec 1984 Mar
PMID:Migration of lymphocytes through the cutaneous basal lamina in normal skin: an ultrastructural study. 672 Dec 30


<< Previous 1 2 3 4 5 6 Next >>