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N G Maroudas

Publications and source records attributed to N G Maroudas.

11 recordsLinked to original sources
PubMed1992

Concentrations of endothelial-cell-stimulating angiogenesis factor, a major component of human uterine angiogenesis factor, in human and bovine embryonic tissues and decidua.

Embryonic development involves the establishment of new patterns of vascular growth in the fetus and within the lining of the womb. A factor, human uterine angiogenesis factor, has been purified from the decidua and stimulates the growth of blood vessels in collagen sponge implants and in the chick chorioallantoic membrane. Evidence is presented that suggests that a major active component of human uterine angiogenesis factor is an activator of latent matrix metalloproteinases, of low M(r), called endothelial-cell-stimulating angiogenesis factor and that this factor is present in substantial quantities in a number of embryonic tissues.

Angiogenesis Inducing Agents↗
PubMed1989

Effect of decidua angiogenic factors on experimental dermis allografts.

Meshed human dermis allografts containing human uterine angiogenic factor were implanted over full thickness surgical skin wounds in rats. Enhanced angiogenesis of the wound bed, three times more than that observed in control grafts, was found in experimental grafts at 3 days postimplantation. This was accompanied by a greater amount of granulation tissue formation, enhanced granulation tissue penetration into the dermal grafts and accelerated incorporation of the grafts. Angiogenesis of the wound bed regressed to control levels at 7 days postimplantation. The growth and penetration of the granulation tissue and the accelerated incorporation of the dermis grafts, however, continued ahead in the experimental grafts while necrosis appeared in the control grafts. The relevance of these results for acceleration of wound healing and improvement of the wound bed for subsequent application of cultured epidermal grafts is discussed. This method may be extended to the treatment of ulcers and burns.

Angiogenesis Inducing Agents↗
PubMed1989

Uterine angiogenic factor induces vascularization of collagen sponges in guinea-pigs.

The need for an adequate blood supply is of prime importance in successful skin grafting and in the take of keratinocyte cultures. Thus, the human uterine angiogenic factor (HUAF) extract, which induces neovascularization of the chorioallantoic membrane (CAM), was employed. The bioassay of HUAF was performed on an in vivo model of subdermally implanted collagen sponges and on sponges implanted into full skin thickness burn wounds in guinea-pigs. The HUAF extract was injected into the sponges every other day for 10 days. Each injection contained 10 micrograms decidual proteins with a total of 50 micrograms/sponge. The animals were sacrificed and the sponge together with the surrounding structures were extirpated, examined macro- and microscopically and by histological techniques. HUAF induced growth of blood vessels from the surrounding vascular bed into the implanted sponges. The angiogenesis was characterized by dense tortuous vessels with centripetal orientation. The control sponges exhibited only sporadic growth of blood vessels. This phenomenon repeated itself in the animals which were inflicted with burn wounds. The present study demonstrates that HUAF extract is also active on the in vivo model of experimental burns and wounds.

Angiogenesis Inducing Agents↗
PubMed1985

Activation of nuclear chromatin in stretch-dependent growth of tissues.

The growth of connective tissue cells can be controlled both by mechanical extension and by diffusion gradients. We have used nuclear fluorescence with acridine orange (AO) as a measure of nuclear activation, to study growth control in vivo in rat mesometrium and mouse spine. Frozen sections of spinal muscle taken from animals after two h exercise, revealed nuclear activation in peripheral cells. The number of active muscle nuclei decreased drastically with age. During mesometrial growth in pregnancy, AO fluorescence showed that activated cell nuclei occurred mainly near the capillaries. The width of the zone of activated nuclei was within 20 microns from the capillary walls. AO appears to be a sensitive stain for tracing gradients of growth in intact connective tissue.

Acridine Orange↗
PubMed1977

Sulphonated polystyrene as an optimal substratum for the adhesion and spreading of mesenchymal cells in monovalent and divalent saline solutions.

Cell adhesion and spreading were studied on sulphonated polystyrene dishes in serum-free saline (Mn, Na, Cl, buffer) i.e., without an intervening protein layer. Spreading as a function of surface charge density, SCD, peaked around 2-10 negative charges per square nanometer, corresponding to a monomolecular layer of sulphonate ions. At optimal SCD, macrophages, BHK-C13 and whole mouse embryo secondary cells all showed considerable spreading, even in monovalent saline-more so than on a conventional tissue-culture surface. But outside this narrow range of SCD, or on protein-coated surfaces, the divalent cation was indispensable. The biphasic effect of sulphonation on cell adhesion is consistent with the theory that a substratum need not be biochemically specific, provided it is physiochemically polar, rigid and dense. According to this theory, polystyrene of sub-optimal SCD would not be sufficiently polar, while supra-optimal sulphonation would produce a hydrogel surface, lacking in local rigidity and density, due to osmotic swelling. The principle of polymer exclusion, by a surface hydrogel layer, is also consistent with observations on the inhibitory effects of adsorbed proteins-viz., albumin, collagen, serum and cellular exudate, respectively-contrasted with the ready attachment of cells to a bare, optimally charged substratum, in this minimal in vitro system.

Animals↗