Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The application of scanning electron microscopy to the study of cell surfaces is limited in intact tissues, because extracellular material may often obscure the details of nonluminal surfaces. To remove connective tissue elements we have treated human skin and both kidney, and an autonomic ganglion of the rat with hydrochloric acid and collagenase. Regional variations in the basal surface of the nephron are noted following removal of the basement membrane. The basilar interdigitations of the cells of the proximal tubule appeared as parallel ridges encircling the tubule. Ridges on the parietal epithelium of Bowman's capsule were randomly arranged and alternated with smooth surfaces. The dermal surface of the human epidermis has an alveolar or honeycomb appearance due to the elevation of the epidermal ridges and numerous pits for the dermal pegs. At higher magnifications the basal surface of cells of the stratum germinativum possessed numerous and irregular projections. Neurons with their processes are evident in the autonomic ganglion. The soma of the neurons are enclosed by flattened satellite cells. Irregular spaces between opposed satellite cells are interpreted as regions for the passage of processes related to the ganglion cells. Nodes of Ranvier were clearly seen along nerve fibers. Some pitting of the nerve fibers was also noted. The HCl-collagenase method has the advantage of the removal of collagen and basement membrane while preserving the structural integrity of the cell surface.
Anat Rec 1976 Aug
PMID:Scanning electron microscopy of cell surfaces following removal of extracellular material. 18 20

To further characterize Sertoli cell-germ cell junctional specializations seminiferous tubules from sexually mature Sprague-Dawley rats were dissociated by enzymatic and mechanical methods. Ultrastructural analysis of cell suspensions prepared by incubation in collagenase alone or by mechanical methods revealed that spermatids remained attached to Sertoli cells or Sertoli cell fragments. Such cellular associations were found only between Sertoli cell fragments and spematids in which the developing acrosome had made contact with the plasma membrane (step 8 and subsequent steps of spermiogenesis). Furthermore, the fragments were confined to that region of the plasma membrane over the acrosome. The Sertoli cell half of this adhesive site displayed the typical elements of Sertoli cell junctions, filamentous bundles and associated cisterna of endoplasmic reticulum, in apposition to the spermatids. The spermatids demonstrated no surface specializations at the attachment sites. In contrast, in cell suspensions prepared with trypsin, spermatids were free of attachments to Sertoli cells or their fragments. These results demonstrate that: (1) the junctions act to bind cells together, (2) adhesive type contact is established between Sertoli cells and spermatids at step 8 and subsequent steps of spermiogenesis, (3) contact is restricted to the spermatid plasma membrane over the acrosome, and (4) spermatids can be freed from the junctional specializations by treatment with trypsin.
Anat Rec 1979 Jan
PMID:Characterization of Sertoli cell-germ cell junctional specializations in dissociated testicular cells. 21 84

The steady decline in plasma progesterone level that occurs during the last week of pregnancy in the normal rat (Wiest, '70) provides good opportunity to study the effect of withdrawal of progesterone on uterine differentiation. Evidence is presented that tissue monocytes, heterophils, and eosinophils are regular components of the normal late gestational uterus and that their number increases as term approaches. Uterine monocytes and heterophils are located in the endometrial and myometrial stroma as well as within the basal intercellular compartment of the luminal epithelium. Stromal monocytes are distributed throughout the attenuated endometrium of late gestation, but are more common immediately beneath the luminal epithelium. In the myometrium, monocytes and heterophils occur, often as perivascular, clusters in the connective tissue septum that separates the two layers of smooth muscle. Eosinophils are present especially in the deep endometrial and myometrial stroma, and increase in number as plasma estrogen rises immediately before parturition. A small population of lymphocytes is regularly present. An important feature of the prepartum uterine stroma is the sparseness of macrophages. Near term, however, the beginnings of monocytic-macrophagic transformation are noticeable as the cell surface becomes more irregular and organelles associated with endocytic activity arise. The prepartum monocytes are positioned in the same histological sites that during the postpartum period of regression will be occupied by macrophages (Padykula and Campbell, '76). Since it is generally accepted that monocytes are precursors of macrophages, this spatial correlation raises the possibility that cellular preparations for regression commence before birth. The possible significance of prepartum monocytic infiltration is discussed in relation to the effect of changing plasma and uterine concentrations of progesterone on uterine collagenase activity. The steady increase in uterine leucocytes which occurs concomitantly with decreasing uterine binding capacity for progesterone supports the hypothesis by Siiteri et al. ('77) that progesterone in high local concentrations has an anti-inflammatory effect.
Anat Rec 1979 Mar
PMID:The occurrence of uterine stromal and intraepithelial monocytes and heterophils during normal late pregnancy in the rat. 21 76

A microanatomical study of the immature rat calvarium was performed in order to develop a method for the isolation of osteoblasts by enzymatic means. Although generalized osteogenesis was evident in fetal rats, differential growth patterns were observed beginning at 19 days in utero. Considerable portions of the endocranial periosteal bone surface were lined by flattened, less active cells; discrete areas also contained multinucleated osteoclasts. Cell counts of whole calvaria revealed that one fifth of the total cell population were osteoblasts, most of which were located in the central portions of the frontal and parietal bones. Prior excision of these segments permitted the subsequent removal of virtually all periosteal tissues. Cleaned 19-day fetal bones, incubated in crude collagenase for two hours, released about 40,000 cells/calvarium, consisting of 85-90% osteoblasts and lesser amounts of connective tissue and bone marrow elements. Because of the relatively small sizes of most extraneous cells, purity on a cell volume basis was approximately 95%. It is predicted this preparation will be useful in the investigation of certain aspects of osteoblastic function.
Anat Rec 1977 Jul
PMID:Enzymatic isolation of osteoblasts from fetal rat calvaria. 90 May 19

The principal cell types associated with the humoral immune response (monocyte-macrophages, lymphocytes, and plasma cells) are numerous in the endometrial stroma of the uterus during the first four postpartum days in two types of mammals, the marsupial North America opossum and the eutherian albino rat. This transietn cellular differentiation coincides with the physiologic period of rapid uterine regression which includes massive reduction in the amount of extracellular stromal material. In addition, heterophils and eosinophils, cell types also known to be associated with phagocytic and immunologic activity, appear in the stroma during the first two postpartum days; their presence may, however, be associated more directly with the postpartum estrus that occurs on day 1 postpartum than with endometrial regression. Thus, the five cell types, which are known in pathologic conditions to be components present in the inflammatory response to a foreign antigen, are conspicuously present in the normal regressing endometrium. Furthermore, there is ample ultrastructural evidence of frequent macrophagic-lymphocytic interaction, transformation of lymphocytes, and active secretion by plasma cells during this early postpartum period. An hypothesis has been derived by uniting this new description of endometrial stromal cell differentiation with the existing literature on uterine collagenase activity, an important feature of postpartum regression (reviews of Gross, '74; Harris and Krane, '74). It is based on the assumption that during regression the extracellular action of neutral collagenase (and possibly other extracellular proteases) release new antigenic sites in proteins located in the ground substance. In the case of collagenase, these transient antigenic sites would arise at the locus of enzymic cleavage as well as from the subsequent denaturation of the fragments of the collagen molecule. This endogenous antigenic stimulus would be strong and temporary, and would lead to the cellular manifestations of the transient humoral immunologic response which are evident in the regressing stroma of these two mammals. This humoral immune reaction may be one of the regulatory mechanisms involved in the cyclic renewal of the extracellular compartment of the uterine stroma.
Anat Rec 1976 Jan
PMID:Cellular mechanisms involved in cyclic stroma renewal of the uterus. III. Cells of the immune response. 125 14

Previous work has demonstrated that adult newt cardiac myocytes possess a proliferative ability in response to an experimentally induced injury, in vivo. This study describes an in vitro model in which the proliferative events of the adult cardiac myocyte may be studied. Ventricles were minced and then enzymatically dissociated in a Ca++- and MG++-free salt solution containing 0.5% trypsin and 625 U/ml of CLS II collagenase for 8 to 10 hours at 25 degrees C. Enzyme digests were preplated and then cultured on bovine corneal endothelial-derived basement membrane "carpets" in either serum-free or serum-supplemented modified Leibovitz's medium for up to 30 days. Light and transmission electron microscopic characterization demonstrated that a majority of the myocytes underwent an initial period of disorganization characterized by a "rounding up" of the cell and a loss of myofibrillar organization. Once the myocytes had attached to the culture substratum they began to spread out, underwent a reassembly of their contractile elements, resumed spontaneous contractions, and demonstrated ultrastructural evidence of protein synthesis. Mitosis was observed in several myocytes 8 to 15 days following isolation. In 15-day serum-supplemented and serum-free cultures, 6.5% +/- 0.9% and 8.1% +/- 1.4% of the myocytes were binucleated, respectively. These results demonstrate that adult newt ventricular myocytes can be successfully placed into primary culture and are capable of undergoing mitosis. This work may be considered as a foundation for future investigations which will focus on the mechanisms which control cardiac myocyte proliferation.
Anat Rec 1989 May
PMID:Primary cell culture and morphological characterization of ventricular myocytes from the adult newt, Notophthalmus viridescens. 265 85

The localization of collagenolytic activity within the tissue compartments of the mouse uterus was investigated during postpartum involution. The rate of collagenase activity was measured by analysis of tissue levels of hydroxyproline from the day of parturition to the 10th postpartum day. Collagen bonding was analyzed by viewing birefringence induced by the picrosirius red-binding technique. An attempt was made to interrelate quantitative analysis with the histologic distribution of collagen during postpartum days 1-10. Histologic and quantitative evidence indicated the following: 1) The collagenous compartments of the endometrium and myometrium differ in their response to the postpartum rise in collagenase activity; collagen degradation occurs primarily in the endometrium, that is, the myometrial collagen remains, but much of the endometrial collagen is removed. 2) Endometrial collagen is degraded particularly in the immediate subluminal compartment.
Anat Rec 1988 Feb
PMID:Removal of collagen bundles in murine uterus during postpartum involution. 335 57

Ultrastructure and three-dimensional architecture of the papillary layer and associated capillaries in the enamel organ of 2-3-month-old kittens were examined by means of routine thin sections, freeze-fracture, and scanning electron microscopy of the tissues digested by HCl-collagenase and of vascular corrosion casts. Outwardly, the papillary layer formed gently sloping upheavals, but did not show prominent papillary ridges. The papillary cells were characterized by a high concentration of intramembranous particles on the plasma membrane P-face, by numerous hemi-annular gap junctions between the cell process of one papillary cell and the cell body of another host cell, and by annular gap junctional vesicles in the subsurface cytoplasm. Some annular gap junctions appeared partially degenerated. These findings led us to speculate that these annular gap junctions are produced by the endocytosis of gap junctional membranes from the cell surface into the subsurface cytoplasm. Capillaries were distributed on the enamel organ within shallow furrows between the papillary upheavals. A part of these capillaries penetrated deeply into the enamel organ but did not contact the ameloblasts. The endothelial walls of the capillaries were pierced with many endothelial fenestrations, especially when facing the papillary layer. The endothelial cell also contained numerous micropinocytotic vesicles throughout its entire cytoplasm. These findings suggest that the papillary cells and associated capillaries are highly specialized for transport of solutes and molecules between the vascular region and the enamel organ during the phase of enamel maturation.
Anat Rec 1986 Apr
PMID:An ultrastructural study of the papillary layer and its vascular bed in the kitten enamel organ. 351 41

The present scanning electron microscopic study describes a new method for the exposure of blood vessels of mouse alveolar bone and myelinated nerves of the dental pulp. This technique differs from others because it does not remove the periodontal ligament, allowing study of the vascular continuity between alveolar bone and periodontal ligament. Fixed and demineralized mandibles are digested with bacterial collagenase (1 mg/ml) at 37 degrees C for 12 hours, exposed to buffered osmium tetroxide for 24 hours, and ultrasonicated at 80 kHz for 5 minutes. The technique demonstrates that the vascular distribution of the interdental and interradicular septa is different. Vessels pass horizontally through the interdental septum and are continuous with vessels of the adjacent periodontal ligament. Vessels of the interradicular septum branch from a central vessel, pass toward the adjacent periodontal ligament, and become continuous with its vessels. Thus, the pattern of vessel distribution of the interdental septum of the mouse has little similarity to that of man or of research animals. The present study provides an improved method for demonstration of bone vasculature and pulpal axons while retaining valuable anatomical landmarks.
Anat Rec 1985 Jan
PMID:Ultrasonic microdissection of the mouse mandible: exposure of the vasculature of alveolar bone and myelinated axons of the pulp. 398 84

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


1 2 3 Next >>