Showing papers in "Differentiation in 1981"

TL;DR: It is concluded that early postimplantation embryonic development, up to mesoderm formation, is characterized by the exclusive presence, in both embryonic ectoderm and proximal endoderm, of differentiated epithelial cells containing desmosome-cytokeratin filament complexes and that other types of intermediate-sized filaments are not yet expressed.

TL;DR: The results suggest that pattern formation in Dictyostelium consists of establishment of appropriate proportions of two cell types and establishment of the pattern itself by a mechanism of sorting-out.

TL;DR: Guinea pig antibodies raised against desmosomal proteins as markers specific to this so far only morphologically define class of junctions are proposed to improve identification and classification of intercellular junctions.

TL;DR: It was shown that the number of desmin containing cells was low distal to the truncus brachiocephalicus, but increases until in distal parts of the aorta and in the arteria iliaca communis almost all cells appear positive for desmin, suggesting that blood vessels show heterogeneity of intermediate filament expression not only in cross-section but can also display heterogeneity along their length.

TL;DR: It is postulated that there is an ubiquitous growth factor in the eye called eye-derived growth factor (EDGF) which may play an important role in physiology and pathology of the eye.

TL;DR: Within an aggregate formed under submerged conditions, prespore cells began to differentiate long before G(+) and G(-) cells were sorted out, indicating that the cell sorting is not a prerequisite for the cell differentiation.

TL;DR: The developing chondrogenic regions appear to lose fibronECTin gradually, concomitant with the appearance of type II collagen, suggesting that fibronectin is not involved in the maintenance of functional chondrocytes in their matrices.

TL;DR: Cell-cell adhesion among prespore cells is much more resistant to EDTA dissociation than 10-h cells and prestalk cells, which may account for the differential cohesiveness of these two cell populations and provide a basis for cell recognition and cell sorting at the slug stage.

TL;DR: GFA expression was not reinduced in cultures that had lost the GFA marker by treatment with dibutyryl cyclic AMP, and the proliferating cultures expressed only the vimentin type of intermediate filament.

TL;DR: It is demonstrated that vegetative amebae possess a significant level of chemotactic responsiveness to folic acid, and a testable hypothesis is proposed for the possible roles of chemoresponsiveness and erasure in late morphogenesis.

TL;DR: Results show that all types of neoplastic and non-neoplastic epithelial cells of mammary gland of both species contain-at least some-filaments of the cytokeratin type identifiable by immunologic reaction, if antibodies are used that recognize a broad range of epidermal and nonepidermal cytokeratins.

TL;DR: Differentiation in mouse embryo development is represented formally by means of a stem-line model in which individual choices are structured so that only a fraction of the cells of a given population receive a signal to undergo a change of state that results in a departure from the stem line.

TL;DR: Factors obtained directly from the eye have a direct ability to control morphology and proliferation of ocular cells like lens cells perhaps by modulation of cellular adhesiveness mediated by surface fibronectin and reorganization of cytoplasmic actin-based filaments.

TL;DR: Results show that quail mandibular epithelium can provide the required developmental instructions for odontoblast differentiation in the absence of serum or other exogenous humoral factors in a chemically-defined medium and suggest the importance of reciprocal epithelial-mesenchymal interactions during epidermal organogenesis.

TL;DR: The findings indicate that the expression of Merocyanine binding sites is developmentally regulated and might, therefore, provide a useful molecular marker for blood cell differentiation and a basis for an effective purification of hematopoietic progenitor cells.

TL;DR: The results indicated that DEX and EGF interact with each other in the process(es) regulating HEPM cell growth, and this interaction may be partially influenced by direct modulation of existing receptors for dextrous factors for EGF and DEX present in the cells.

TL;DR: It is learned that both MNNG and 4NQO only alter behavior of the newt regeneration cells without excreting their carcinogenic effects on them, and that the newT cells are highly resistant and stable against the above-mentioned carcinogens.

TL;DR: The recent finding that invagination or evagination of an epithelial monolayer can be induced following transposition of grafts between proximal and distal extremes of the moth pupal wing has provided new support for this idea.

TL;DR: Most turtle species seem to be endowed with a ZZ/ZW sex determining mechanism, and in these species the female was typed as H-Y antigen positive, only in Chinemys reevesi was the male H-y antigen positive.

TL;DR: Vitellin, the main fraction of the soluble yolk proteins, was prepared from Nereis virens oocytes and was found to resemble both insect vitellins and an average protein, as defined by other authors.

TL;DR: The early appearance of immunoreactive LH-cells following a precise distribution shows that secretory properties and differentiation capacities are acquired simultaneously in the epithelium of the Rathke's pouch and may be induced by the same stimulus.

TL;DR: Cell reorganization experiments in vitro were performed with dissociated rat testes at different ages of postnatal development namely, newborn, 8-10, 18-25, 35-40, and 90 days, finding only newborn and juvenile rat testicular cells reassociated into testicular-like organization in rotation culture.

TL;DR: Investigation of Xenopus unfertilized eggs and early developmental stages revealed structural differences between Xenopus laevis muscle actin and nonmuscle cell actin, and the presence of an actin shell around the yolk platelets was explained.

TL;DR: The results show that in such an in vivo culture system, the chimeric associations gave rise to well differentiated intestinal structures indicating that the epithelioid cell cultures derived from late embryonic or neonatal intestine will go through organotypic differentiation when recombined with an appropriate mesenchyme.

TL;DR: It is assumed that H-Y antigen secreted by male gonadal cells is bound by the ovarian receptor sites and induces conversion into tubular structures and H-y antigen integrated into the cell membrane of nongonadal male cells does not seem to be able to exert this morphogenetic effect.

TL;DR: The results of these studies suggest that a teratoma shoot does not depend for its development on the presence of significant numbers, if any, of cells that had recovered from the tumorous state, and the tumory state may be suppressed in even the most highly specialized cells.