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  • Collagen  (2)
  • Macaca mulatta (Primates)  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 274 (1993), S. 135-144 
    ISSN: 1432-0878
    Keywords: Trophoblast ; Uterus ; Veins ; Basement membrane ; Placenta ; Macaca fascicularis (Primates) ; Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Trophoblast cells invade and modify the uterine vasculature to provide circulation of maternal blood through the placenta. Although evidence indicates fundamental differences between trophoblast modification of arteries and veins, interactions between trophoblast cells and uterine veins have not been addressed. In this report we describe the processes by which trophoblast cells invade and restructure uterine veins during placentation in the macaque. Antibodies were used to identify trophoblast, endothelium, and basement membranes. During early gestation, trophoblast migrated from the trophoblastic shell and, by intravasation, replaced portions of the wall and endothelium of veins in the vicinity of the shell; this is in contrast to invasion by extravasation reported for the arteries in this species. These areas had discontinuous endothelial basement membranes and the endothelial cells were variably hypertrophied. Deeper portions of veins were not invaded; this too is in contradistinction to the spiral arteries where trophoblastic modification extends to the myometrial segments. Later in gestation, those portions of veins interacting with trophoblast were contained within the trophoblastic shell or situated such that one side abutted the shell. These regions of the veins were lined by endothelium, but it could not be determined whether this represented re-endothelialization of regions formerly lined by trophoblast or if these endothelial cells were never displaced.
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  • 2
    ISSN: 1432-0878
    Keywords: Trophoblastic cells ; Spiral artery ; Extracellular matrix ; Uterus ; Macaca fascicularis (Primates) ; Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The processes by which trophoblast cells invade and modify the walls of the uteroplacental arteries of macaques during the course of gestation were examined. Antibodies to cytokeratins were employed to identify trophoblast, anti-desmin antibody to identify smooth muscle, and antibodies to type IV collagen, laminin, and fibronectin to examine changes in extracellular matrix distribution in the arterial wall. During early gestation, endovascular trophoblast adhered to the arterial wall, often in an asymmetrical distribution. As trophoblast cells moved outwardly into the tunica media, the basement membrane underlying the endothelium was lost, as indicated by gaps in the layer when stained for type IV collagen and laminin. Trophoblast cells became sequestered in the vessel wall where they hypertrophied and became surrounded by a capsule containing type IV collagen and laminin. As the trophoblast cells became established in the vessel wall, the muscular layer of the artery became discontinuous. Throughout gestation it was common for trophoblast cells to invade the vessel intimal layer and share the lining of the artery with typical endothelial cells. This general disposition of endovascular and intramural trophoblast persisted into late gestation. In addition, and contrary to the results of earlier studies of macaques, we identified trophoblastic invasion and modification of myometrial segments of the uteroplacental arteries in later gestation. We also found evidence of interstitial trophoblast cells among the stromal cells of the endometrium, especially during early gestation.
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  • 3
    ISSN: 1432-0878
    Keywords: Trophoblast ; Placenta ; Laminin ; Collagen ; Fibronectin ; Extracellular matrix,-structures ; Macaca fascicularis (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cytotrophoblastic cell columns and trophoblastic shell of macaque placentas accumulate progressively greater amounts of intercellular material during early gestation. We studied the composition of this material in placentas collected from 22–34 days of gestation by using immunoperoxidase techniques directed to the extracellular matrix molecules fibronectin, type IV collagen, and laminin. These antigens co-localized within the intercellular deposits at all stages studied. At day 22 the proximal cell columns were composed of cells with narrow interstices and which lacked immunoreactivity for the 3 antigens. Distally the cells were vacuolated and the intercellular spaces increased in size and contained dense matrix deposits. The trophoblastic shell consisted of closely packed, non-vacuolated cytotrophoblast cells with only a delicate meshwork of matrix. By day 27 the matrix deposits of the distal cell columns increased markedly in size. The trophoblastic shell contained larger numbers of vacuolated cells and was occupied by accumulations of matrix. By 34 days the matrix deposits of the cell columns expanded substantially along the longitudinal axes of the columns. These deposits were often continuous with a matrix-dense, cell-deficient layer in the trophoblastic shell. This matrix-rich zone lay between a cellular layer adjacent to the intervilous space and a similar, but discontinuous, cell layer that formed the junctional zone with the endometrium.
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  • 4
    ISSN: 1432-0878
    Keywords: Trophoblast ; Placenta ; Laminin ; Collagen ; Fibronectin ; Cytokeratin ; Extracellular matrix ; Macaca fascicularis, Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Developmental changes in the organization of cells and extracellular matrix in the cell columns and trophoblastic shell of macaque placentas have been examined between 37 days of gestation and term. Between 37 and 53 days a thickened basement membrane developed between the trophoblast cells of the proximal cell columns and the mesenchymal cores of contiguous anchoring villi. This layer stained strongly for type IV collagen and laminin, but weakly for fibronectin. Large “lakes” of extracellular matrix immunoreactive for all 3 of these antigens were present in the distal columns, while smaller amounts were distributed between cells of the proximal columns. During this period the trophoblast cells in the proximal shell reorganized, forming strands of cells that were separated by bands of matrix immunoreactive for type IV collagen, laminin, and fibronectin. Staining for these antigens decreased abruptly at the junction between fetal and maternal tissues. Between 66 and 104 days the thick basement membrane of the proximal columns persisted, but stained only weakly for each of the 3 extracellular matrix antigens. The large lakes of matrix in the distal columns characteristic of earlier stages gradually disappeared. The cell columns became progressively shorter and the tips of the anchoring villi became embedded in the trophoblastic shell. The matrix of the shell decreased in immunostaining intensity except for narrow rims around the trophoblast cells. Gestational ages later than 104 days showed few additional changes in the distribution of the matrix antigens or cell organization of the columns and shell. The thick basement membrane-like layer persisted to term although it continued to stain weakly for the 3 matrix antigens. The distal ends of most anchoring villi were embedded in the trophoblastic shell. The developmental changes in the organization of the columns and shell may be related to changes in placental growth rate.
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