(n.) The hard outer covering of hydroids and other marine animals; the perisarc.
Example Sentences:
(1) Immunoreactivity was restricted to the periderm and intermediate layers of fetal epidermis at 55 d of gestation, when the first wave of wool follicles are initiated.
(2) Simple epithelial CK are expressed in all cell layers during the early stages, essentially in peridermal cells.
(3) The ER stained with DiOC6 (3) was prominent in both the periderm and basal cells.
(4) The H antigen showed a variable and weak expression on peridermal cells from day 57 to day 84 estimated gestation age (EGA).
(5) After 140 days, however, keratin appears in the superficial layers of the periderm; the bladder cells degenerate and become 'rosette' cells, and glycogen and alkaline phosphatase begin to disappear.
(6) When a semipermeable membrane is interposed between the cells and the epidermis, the latter does not degenerate, but keratinizes without showing the usual stages of differentiation.The malignant cells sometimes cause hypertrophy of the epidermis when cultured beneath the dermis of intact skin, but have no effect when grown on the peridermal surface of this tissue or of isolated epidermis.Freeze- or heat-killed dermal cells, whether normal or malignant, provide an unsuitable substratum for epidermal survival, possibly due to adsorption of intracellular constituents on to their surfaces.IT IS SUGGESTED THAT THE MALIGNANT FIBROBLASTS EXAMINED PRODUCE AT LEAST TWO SUBSTANCES HAVING AN EFFECT ON EPIDERMIS: one of small molecular size affecting differentiation, and a toxic macromolecule.
(7) Dense bodies are present within mitochondria, nuclei, glycogen pools and the peridermal cytoplasm.
(8) Immunostaining was seen in vivo in all regions of the palatal epithelium with superficial peridermal cells staining most intensely.
(9) In the 18 to 20 day fetuses, no periderm is present.
(10) This study shows that different patterns of scutate scale type beta keratins are accumulated in the three adjacent structures of the embryonic chick beak: periderm, egg tooth, and cornified beak.
(11) The periderm is lost during the first week of postnatal development.
(12) The periderm in these fetal cultures formed blebs early but was sloughed with the stratum corneum in older cultures.
(13) In the epithelial cells both the periderm and basal cells contained these procollagens within the cytoplasmic organelles.
(14) The periderm cell layer had disorderly fusion at the outer canthus, premature flattening, and failure to fuse in the inner canthus.
(15) Type V collagen was also localized in basal and periderm cells of the epidermis.
(16) These proteins were retained in the outer layers of peridermal cells and in some cells of the basal layer (probably Merkel cells).
(17) Acting in concert, growth factors could regulate events critical to formation of the secondary palate, including cessation of medial epithelial cell proliferation, synthesis of extracellular matrix proteins in the mesenchyme, programmed cell death of medial epithelial peridermal cells, and transformation of basal epithelial medial cells to mesenchymal cells.
(18) In the 12-day embryo, the periderm forms a complete layer.
(19) The changes in the periderm observed with the scanning electron microscope have been correlated with and supplemented by cytologic studies with the transmission electron microscope in the periderm and other epidermal layers.
(20) The periderm cells present form a flattened band along the eyelid margin rather than, as in normal eyelids, along the fusion line.
Perisarc
Definition:
(n.) The outer, hardened integument which covers most hydroids.
Example Sentences:
(1) In this region coenosarc is just beginning to separate from the perisarc.
(2) The distal location of forming desmocytes is coincident with the hardening of new perisarc.
(3) Support provided by the desmocytes to the upright stolon is limited by three factors that characterize the athecate hydroid: distribution of perisarc, pattern of growth, and extent of movement.
(4) These cells are characterized by accumulations of 70 A filaments which aggregate into dense rods at the apical end and contact the perisarc.
(5) Desmocytes or anchoring cells are present on the upright stolons of the athecate hydroid Cordylophora caspia and function to support the soft coenosarc within the rigid tube of perisarc by linking the perisarc with the mesoglea.