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Biomedical subjects

G Godeau

Publications and source records attributed to G Godeau.

At least 73 records · Page 4Linked to original sources
PubMed1988

Characterization of an antibody directed against a 128 kDa glycoprotein involved in the thrombogenicity of the elastin-associated microfibrils.

We have developed a monospecific antiserum directed against a major glycoprotein in the elastin-associated microfibrils with an apparent molecular mass of 128 kDa (GP 128). When immunoblotting or enzyme-linked immunosorbent microassay was used, its IgGs recognized thrombospondin in a platelet lysate, but did not react with several basement-membrane-derived macromolecules, nor with plasma fibronectin. Similar patterns of immunofluorescence and immunoperoxidase were found after incubation of endothelial cells with either anti-GP 128 or anti-(platelet thrombospondin) IgGs. Both antibodies inhibited the microfibrils- and thrombin-induced platelet aggregation, and were without effect on the aggregation by other inducers. These results confirm that there is an antigenic homology between GP 128 and thrombospondin.

Blood Coagulation↗
PubMed1988

Characterization of human skin fibroblasts elastase activity.

We present evidence that enzyme activity hydrolyzing Succinoyl trialanine paranitroanilide (Suc(Ala)3NA) expressed by Human Skin Fibroblasts (HSF) in culture could be attributed to the concerted action of an endopeptidase and an aminopeptidase(s). Both endopeptidase and aminopeptidase activities were strongly inhibited by metal chelating agents and Copper and Zinc ions but were insensitive to Tissue Inhibitor of Metallo Proteases (TIMP). These protease activities coeluted on ion exchange chromatography (DEAE Tris acryl M) and were further separated by high-performance liquid chromatography HPLC (TSK 3000 SW). The endopeptidase activity, designated as HSF E1, was eluted at the position corresponding to an Mr equal to 94,000. It has only a limited elastinolytic potential as evaluated on 3H insoluble elastin, but it extensively degrades human skin elastic fibers as directly assessed on human skin tissue sections and further quantitated by automated image analysis. The level of HSF E1 increases with the number of fibroblast passages.

Adult↗
PubMed1988

[Action of testicular hyaluronidase on macromolecules of the cutaneous extracellular matrix. Study by computerized image analysis].

The aim of this work was to precise the action of testicular hyaluronidase (Thiomucase, Millot Solac, Sanofi, France) on the extracellular matrix macromolecules of the skin in an experimental animal model. Intradermal injection of hyaluronidase in the rabbit acts on proteoglycans which are degraded. Collagen bundles are dissociated. This is due to endoglycosaminidase activity of the hyaluronidase on dermal proteoglycans. The network of the elastic fibers was not altered by the enzyme injections, this suggest the absence of elastolytic activity in the Thiomucase preparations. The dissociation of collagen bundles and the degradation of proteoglycans are followed by the resynthesis of the initially degraded proteoglycans. The observed morphological changes which follow the intradermal injection of hyaluronidase, confirm the ability of this enzyme to influence the composition and the structure of the dermis.

Animals↗
PubMed1988

Morphometric analysis of the degradation of human skin elastic fibres by human leukocyte elastase (EC 3-4-21-37) and human skin fibroblast elastase (EC 3-4-24).

The degradation of human skin preelastic fibres (PEF) namely oxytalan and elaunin fibres, and that of mature skin elastic fibres (EF) by human leukocyte elastase and purified human fibroblast elastase was studied by morphometric analysis. Leukocyte elastase hydrolyzed both types of fibres; Elaunin and mature elastic fibres were found particularly sensitive to degradation by this proteinase. Skin PEF and EF from 59-67 yr-old individuals were degraded to a greater extent by this proteinase than those from the two younger individuals analyzed (18 and 24 yrs old). Human skin fibroblast elastase mainly hydrolyzed PEF. It possessed only a limited action toward mature dermal elastic fibres. At the highest dose of proteinase used, the volume fraction of EF was reduced by 50% in youngest skins and by 25% in the oldest ones.

Elastin↗
PubMed1988

Evolution of the elastic fiber network of the human uterine cervix before, during and after pregnancy. A quantitative evaluation by automated image analysis.

To assess the evolution of the elastic fiber network of the human uterine cervix before, during and after pregnancy, biopsy samples were obtained from 49 women. The high affinity of the polyphenolic compound (+)-catechin for elastin was used to stain the elastic fibers selectively, and enabled automated image analysis. In the human uterine cervix, the elastic fiber network is made up of: (1) fibers running parallel to the basement lamina of the epithelium, and (2) thinner, perpendicular fibers. Quantification using automated image analysis shows a decline in the cervical elastin content from a prepregnancy level of 1.33 +/- 0.08 (SEM) to 0.73 +/- 0.09% (Vv) at the end of pregnancy. In parallel with a constant decline, dissociation and disorganization of the fibers become more clearly evident as pregnancy progresses. However, by 5-7 weeks postpartum the elastic fiber network appears almost completely restructured. These changes support a role of elastin in the processes of cervical maturation and reconstruction during pregnancy and after delivery.

Adolescent↗
PubMed1987

Effect of chromocarb diethylamine on the permeability of the blood-brain barrier.

Intravenously injected collagenase, detectable in brain microvessels by immunological methods, partially degrades the constituents of the vascular wall and so increases the permeability of the blood-brain barrier (BBB). Intravenous administration of collagenase is a model for diseases in which the concentration of endogenous proteases is increased. Peroral treatment of rats with chromocarb diethylamine (CD) significantly reduced the degradation of the vascular wall by intravenous collagenase, as demonstrated by a lesser permeability increase of the BBB, a shorter recovery time, lower hydroxyproline levels in the cerebrospinal fluid and a lesser decrease of the collagen content of the brain capillary basal lamina.

Animals↗
PubMed1987

[Histophysiology of the uterine isthmus].

The uterine isthmus is morphologically defined as a topographic zone between the uterine corpus and the cervix, in very close association with the vasomusculary afferences. Architecturally isthmus corresponds to the connective-muscular function which is different by its thickness (from 2 mm to 10 mm) and by its morphology (digited, undulating sharp and regular). Histologically isthmus is made up by collagen fibers myometrial muscle cells, irregularly directed. The relationship of these two components reveal their functional synergy between the predominance of the connective tissue and the weakners of the muscle cells. The specific function of the isthmus and its autonomy depend: of the type and direction of the collagen fibers, and the quantity and arrangement the muscle cells, of the biochemical modifications and the variability of the ground substance moreover of the relations with the nervovascular endings. The isthmus incontinence is associated with these structural anomalies (muscular components, elastic fibers defects, connective tissue pathology, activity of the nerve endings, enzymatic troubles under hormonal control).

Collagen↗
PubMed1986

A selective histochemical method for the quantitative estimation of elastic fibers by computerized morphometric analysis. Effect of colchicin treatment.

A morphometric technique is reported that uses a new selective staining of the elastic system fibers in skin biopsy specimens to facilitate the quantitative evaluation of the volume fraction occupied by these elastic fibers in the tissue. The study of elastic fibers in the dermis of 30 patients, before and after six months of treatment with Colchicin, was carried out with a Quantimet 720 system. Preelastic (oxytalan and elaunin) fibers and mature elastic fibers were quantitated separately. Compared to the average volume fraction (surface occupied by the elastic fibers) before treatment with Colchicin (1.449 +/- 0.64%), the mean values after treatment were significantly increased (2.076 +/- 0.61%). The same results were found for the preelastic fibers: 0.807 +/- 0.51% before treatment and 1.025 +/- 0.54% after treatment. These results demonstrate the advantages of our monochromatic staining method for automatic quantitation of elastic fibers as well as the possibilities of the quantitative study of the elastic fibers in human dermis. This methodology should be applicable to other inherited or acquired diseases affecting skin elastic fibers as well as to other tissues containing elastic fibers.

Colchicine↗
PubMed1985

Comparative distribution patterns of type I and III collagens and fibronectin in human arteriosclerotic aorta.

The distribution patterns of type I and III collagens and fibronectin were studied in arteriosclerotic lesions of human aortas as well as in the regions devoid of any macroscopic lesions of the same aortas. Frozen sections were analyzed for fibronectin and collagens by indirect immunofluorescence or immunoperoxidase analysis with specific antisera prepared in rabbits against human plasma fibronectin and against human type I and III collagens. Tissue samples were also stained for type I and III collagen distribution using Picro Sirius red according to the method described by Junqueira et al. (1979). In the regions devoid of any visible macroscopic lesions, there is a co-distribution in the media of the aortic wall of type I and III collagens, with a predominance of type I collagen. Type I collagen is also visible in the intima, as a continuous layer. This is attributed to an age-dependent change of the aorta (arteriosclerosis). Fibronectin can be demonstrated as a thin layer in the subendothelium and as a weak immunofluorescence over the media. In recent or evolutive arteriosclerotic plaques, fibronectin and type III collagen appear to be strongly increased and superimposed. There is also an increase of type I collagen in the intimal region of the plaque. The co-distribution of type III collagen and fibronectin in the arteriosclerotic plaques may suggest a tissue-repair-type of process, analogous to that which can be observed during wound healing. Our results suggest that in arteriosclerotic lesions, type III collagen and fibronectin are predominantly synthesized.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1985

Effect of colchicine on atherosclerosis. III. Study of dermal elastic fibers by quantitative histochemistry, automated image analysis.

Computerized automatic-image analytical procedure was applied on dermal biopsies stained for elastin by a new procedure giving a completely white background and staining only the elastic fiber system. In arteriosclerotic hypertensive patients, a 3-4 months' treatment with 1 mg colchicine per day resulted in a significant (60-80%, p less than 0.01) increase of the dermal elastic fiber density both in the superficial papillary dermis and in the deep dermis. This result shows that the age-dependent increase of elastic fibers can be influenced by pharmacological means. The inhibition by colchicine of the synthesis and secretion of the fibroblast-derived metalloelastase-type protease could be a plausible explanation of this finding.

Adult↗
PubMed1984

Evidence by in vivo and in vitro studies that binding of pycnogenols to elastin affects its rate of degradation by elastases.

Procyanidol oligomers and (+) catechin bound to insoluble elastin markedly affect its rate of degradation by elastases. Insoluble elastin pretreated with procyanidol oligomers (PCO) was resistant to the hydrolysis induced by both porcine pancreatic and human leukocyte elastases. The quantitative adsorption of pancreatic elastase was similar on either untreated or PCO-treated elastin suggesting that the binding of this compound to elastin increases the non-productive catalytic sites of elastase molecules. (+) Catechin-insoluble elastin complexes were partially resistant to the degradation induced by human leukocyte elastase but were hydrolysed at the same rate as untreated samples by a constant amount of pancreatic elastase. In addition, the coacervation profile of kappa-elastin peptides as a function of temperature is greatly modified in presence of these flavonoids. We conclusively evidenced that PCOs bind to skin elastic fibres when injected intradermally into young rabbits. As a result, these elastic fibres were found more resistant to the hydrolytic action of porcine pancreatic elastase when injected to the same site. These in vivo studies further emphasized the potential effect of these compounds in preventing elastin degradation by elastase(s) as occurred in inflammatory processes.

Animals↗
PubMed1984

Ultrastructural and biochemical modifications of rabbit arteries induced by immunization with soluble elastin peptides.

Immunization of rabbits with soluble elastin peptides (kappa 1-elastin) in complete Freund's adjuvant resulted in morphological and biochemical modifications in aorta and in lung arterioles. The elastic fibers of both tissues appeared fragmented at the light microscopical and ultrastructural levels. The presence of IgG at the site of lysed elastic fibers could be evidenced by immunological techniques. In agreement with these findings, a significantly increased elastase-type protease activity could be demonstrated in aorta extracts from the immunized animals as compared to those obtained from control animals. The biosynthetic activities of aorta explants of rabbits immunized with kappa 1-elastin maintained in organ culture conditions were considerably reduced, as shown by the decrease of incorporation of [14C]lysine and [14C]glucosamine in aorta macromolecules. These results show that anti-elastin antibodies may well be involved in the pathological modifications of the arterial wall and especially in the triggering of the degradation of elastic lamellae.

Animals↗
PubMed1984

Interaction between elastin and elastases and its role in the aging of the arterial wall, skin and other connective tissues. A review.

Elastic fibers are progressively lysed during maturation and aging and in an accelerated fashion in several aging diseases such as diabetes, arteriosclerosis, emphysema and several skin diseases. Several enzymes (elastase-type proteases) were isolated in recent years in our laboratory which appear to be involved in these processes. A cell membrane bound serine protease was isolated from arterial smooth muscle cells and was shown to increase with in vitro aging of the cells. A metallo-protease was isolated from skin fibroblasts and was shown to be capable of attacking the constituents of elastic fibers, mainly the microfibrillar glycoproteins and also the desmosine cross linked elastin in vivo. This partially purified fibroblast enzyme was shown to attack these elastic fibers when injected into the dermis. A new selective staining procedure was used to visualise and quantitate, by computerized image analysis, the skin elastic fibers in normal and pathological human or animal skin biopsies. This method, combined with the injection of elastase in rabbit skins, alone or together with inhibitors, enables the ex vivo/in vivo study of elastase action (and of its inhibition).

Adult↗
PubMed1984

On the presence of a metalloprotease in human skin fibroblasts that degrades the human skin elastic fiber system.

Succinyl-trialanine paranitroanilide, a specific synthetic substrate of elastases, was shown to be hydrolyzed by Triton X-100 extracts of human skin fibroblasts at near neutral pH. The neutral endopeptidase has been partially purified by ion exchange chromatography (DEAE Sephadex) and affinity chromatography using an AH-Sepharose (Ala)3 column. The enzyme has been purified 85-fold and appears to be a metalloprotease as shown by its inhibitory profile. In its partially purified form, the neutral endopeptidase was found inactive toward benzoyl arginine paranitroanilide, benzoyl tyrosine paranitroanilide, azocasein, type I collagen, and [3H]ligamentum nuchae-insoluble elastin. Structural glycoprotein microfibrils isolated from porcine aorta are extensively degraded by this neutral protease. It could also hydrolyze, but to a lesser extent, insoluble elastin purified from human aortas; it was, however, found inactive toward bovine ligamentum nuchae elastin. Its potentiality to degrade the human skin elastic fiber system (namely elastic fibers, oxytalan, and elaunin fibers) has been assessed by a morphometric analysis of the length of these fibers (on tissue sections appropriately stained to identify the components of the elastic fiber system) prior to and after enzyme action. Analysis of the data obtained by morphometry indicated that this neutral protease attacked rapidly both elaunin and oxytalan fibers of human dermis, but only slowly the mature elastic fibers.

Cells, Cultured↗
PubMed1984

[Experimental study of the effects of cyaninoside chloride on collagen, and its potential value in ophthalmology].

Cyaninoside chloride is a drug used in the treatment of visual functional troubles in low-luminance conditions, in patients suffering from myopia and night blindness. Its effects on the enzymatic degradation of collagen by collagenase have been studied by means of two experimental models: collagen-collagenase diffusion plates, in vitro, permeabilization of the blood-brain barrier by collagenase, in rats, in vivo. The results obtained point out that cyaninosides chloride protects the collagen against the enzymatic attack due to collagenase. In the light of these results, it is possible to propose a mechanism for the action of this drug on the external blood-retinal barrier.

Animals↗
PubMed1984

Selective staining technique for identification of human skin elastic fibers.

The staining methods proposed for the histological detection of elastic fibers are not entirely selective for the elastic fiber system and stain other tissue components also as for example nuclei and collagenous components. We worked out several staining methods which enable us to obtain a selective staining of all the elastic and pre-elastic fibers with no staining of the background by using in the staining solution polyphenols like: pyrogallol, (+) catechin, tannic acid and others. As the background is colourless, our method is suitable for the quantitation of elastic system fibers by automated computerized image analysis.

Adult↗
PubMed1983

Immunohistochemical detection of fibronectin using different fixatives in paraffin embedded sections.

Different fixatives and immunohistochemical methods were tested for detection of fibronectin in various paraffin embedded tissues: rat kidney, spleen, gastro-intestinal tract, muscle, normal and fibrotic liver and human skin. Using cryostat sections, localisation with immunofluorescence and peroxidase technics comparable to those obtained in unfixed tissue sections, could be obtained with the following fixatives: 10% formalin in PBS containing 4% sucrose; 96% ethanol; 96% ethanol + 1% acetic acid; a series of ethanol solutions of increasing strength: 70-80-96%. These fixatives also proved to be the best for paraffin embedding. Without enzyme digestion, however, satisfactory results could not be obtained with either indirect peroxidase or immunofluorescence methods in paraffin embedded tissues. Following digestions with the enzymes at the concentrations described in the literature, the alteration of tissues made the morphological localization of fibronectin difficult. The self-sandwich peroxidase method following a gentle pepsin digestion gave results closest to those of unfixed cryostat sections; however a slight increase in background staining was observed but without interfering with the evaluation of results.

Fibronectins↗