Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
J Hazard Mater ; 152(2): 516-26, 2008 Apr 01.
Article in English | MEDLINE | ID: mdl-17884284

ABSTRACT

The objective of the MITRA (monitoring and intervention for the transportation of dangerous goods) project was to prototype a new operational system for monitoring the transportation of dangerous goods in Europe based on regional responsibilities. This concept, based on systems used in air traffic control, aims to provide civil security centres with real-time knowledge of the position and contents of dangerous vehicles circulating in their area of responsibility, and, in the event of a dangerous situation, to issue warnings, alerts and crisis management information, thereby allowing intervention teams to react immediately with maximum safety. The project was funded by the European Commission under the 6th Framework Programme (STREP--specific targeted research project--under the Information Society Technologies priority). It started on 1 September 2004 and ended on 31 October 2006. This paper presents the results of this project and the conclusions derived from the field tests carried out in Germany and in the French/Spanish border region in order to test the proposed operational system.


Subject(s)
Hazardous Substances , International Cooperation , Transportation/standards , Accidents, Occupational , Europe , Safety
2.
J Hazard Mater ; 130(3): 251-64, 2006 Mar 31.
Article in English | MEDLINE | ID: mdl-16137827

ABSTRACT

This work has been carried out in the framework of the ARAMIS project, which aims at developing a comprehensive procedure for assessing the risk level associated to an industrial site with respect to the surrounding environment. To this end, an index is defined which consists of the contribution of three terms, expressing the severity of the scenario consequences, the efficiency of the safety management and the vulnerability of the surrounding environment. The present work focuses on this last aspect concerning the determination of the vulnerability, of the area in the vicinity of an industrial site, of human, environmental (or natural) and material stakes. The applied methodology consists in identifying and quantifying the targets by the means of a geographical information system (GIS) and in assessing the contribution of each target on the basis of a multicriteria decision approach (Saaty method). The result is an operational tool allowing competent authorities, industrialists and risk experts to assess the vulnerability of the area surrounding an industrial site.


Subject(s)
Chemical Industry/standards , Environmental Exposure/prevention & control , Environmental Monitoring/methods , Geographic Information Systems , Hazardous Substances , Risk Assessment/methods , Safety Management/methods , Causality , Chemical Industry/organization & administration , Containment of Biohazards/methods , Decision Making , Europe , European Union , Guidelines as Topic , Humans , Models, Statistical
3.
J Fr Ophtalmol ; 26(5): 456-63, 2003 May.
Article in French | MEDLINE | ID: mdl-12819602

ABSTRACT

PURPOSE: To compare the predictability, efficacy, and safety of two methods of Lasik correction of compound myopic astigmatism: positive cylinder ablation versus negative cylinder ablation. METHODS: Twenty nine eyes of 19 patients were retrospectively analyzed. They had undergone Hansatome or ALK-e flap keratectomy, and a Technolas Keracor 217c laser ablation. Group 1 (14 eyes) was corrected with the positive cylinder program, group 2 (15 eyes) with the negative cylinder program. Spherical equivalent (SE), cylinder, vector analysis, and best corrected and uncorrected visual acuities (BCVA, UVA) were compared in the two groups. Minimum follow-up was 6 months. RESULTS: The preoperative mean SEs for groups 1 and 2 were, respectively, - 7.09+/-3.36 D and - 8.05+/-2.27 D (NS). Mean cylinders were 1.73+/-0.88 (group 1) and +/-0.74 (group 2) D. Visual acuities were not statistically different in the two groups. Postoperative mean SEs were, respectively, - 0.57+/-1.58 D and - 0.68+/-0.88 D. Mean cylinder was, respectively, 0.57 +/- 0.54 D and 0.7 +/- 0.46 D in groups 1 and 2. Astigmatism induced by surgery, calculated by vector analyses was, respectively, 1.36 +/- 0.66 D and 1.54 +/- 0.56 D. Percentages of UVA above 20/25 were, respectively, 50% and 35%. None of those differences was statistically significant. One eye lost one line of BCVA. CONCLUSION: The positive cylinder ablation method makes a larger optical zone of ablation possible with the same central deepness of ablation. We found that the predictability, efficacy, and safety of this technique compares well with the negative cylinder ablation in compound myopic astigmatism.


Subject(s)
Astigmatism/surgery , Catheter Ablation/methods , Myopia/surgery , Refraction, Ocular/physiology , Catheter Ablation/instrumentation , Equipment Design , Follow-Up Studies , Humans , Postoperative Period , Retrospective Studies , Time Factors , Treatment Outcome
4.
Presse Med ; 31(34): 1607-12, 2002 Oct 19.
Article in French | MEDLINE | ID: mdl-12426979

ABSTRACT

THE IMPORTANCE OF VISUAL FUNCTION IN THE ASSESSMENT OF QUALITY OF LIFE: The notion of visual function is related to visual acuity but also to many other parameters such as the visual field, perception of colour, contrasts, and the resistance to blinding. These factors are difficult to measure during routine ophthalmic examination but can be assessed during questionnaires on quality of life. MARKERS OF QUALITY OF LIFE IN OPHTHALMOLOGY: Various quality of life questionnaires have been developed in ophthalmology because the non-specific generic instruments appear inadequate. The SF 36 and SF 20 scales, which are generic instruments widely used in many fields, do not adequately explore the problems related to vision. The first efficient instrument is the VF 14, which is a questionnaire specific to ophthalmic diseases, developed by C. Mangione in 1992. This self-administered questionnaire permits calculation of a 0 to 100 score exploring 5 dimensions (long-sight acuity, near-sight acuity, unclear sight, and driving during the day and at night) during 14 activities with 18 questions. It was translated and adapted into French by Gresset in 1997. Today it is the most commonly used questionnaire in ophthalmology, particularly in the assessment of efficacy and impact in surgery. Along the other specific questionnaires developed, there is the NEI-VQF which was created in 1995 to assess vision and the impact of visual problems on the quality of life of patients, independently of an ophthalmic pathology. Many studies have been conducted on various diseases that affect vision, such as diabetes or hypertension. THE LIMITS OF EXISTING INSTRUMENTS: The specific scales appear far more sensitive and specific than generic scales with regard to ophthalmic problems, but they provide less information on the general status of the patient, except for the NEI-VQF. They are limited in some parameters and do not, unfortunately, take into account the patient's age. No specific scale has been developed for children or adolescents, although the impact of vision on daily life is fundamental. The complexity of vision means that the elaboration of an ideal instrument is difficult. However, in the meantime, it is essential that the practitioners continue to use and to test the instruments available in order to improve with regard to pathologies, or in particular sub-groups of the population.


Subject(s)
Eye Diseases , Quality of Life , Surveys and Questionnaires , Vision Disorders , Activities of Daily Living , Adolescent , Adult , Aged , Automobile Driving , Blepharoptosis/surgery , Cataract , Cataract Extraction , Child , Eye Diseases/psychology , Eye Diseases/therapy , Glaucoma , Humans , Middle Aged , Patient Satisfaction , Time Factors , Vision Disorders/psychology , Vision Disorders/therapy , Vision, Ocular , Visual Acuity , Visual Fields
5.
J Fr Ophtalmol ; 25(7): 685-93, 2002 Sep.
Article in French | MEDLINE | ID: mdl-12399724

ABSTRACT

PURPOSE: Human amniotic membranes have recently been used in ophthalmology to restore deleted ocular surface after burns. Matrix metalloproteinases-2 and -9 have been implicated in the development of neovascularization. In this study, MMP-2 and MMP-9 expression was analyzed by in situ zymography on rabbit corneal chemical burns with and without human amniotic membrane graft. METHOD: Corneal neovascularization was induced in 10 Fauve de Bourgogne rabbits by means of a heptanol chemical burn on controlled deep keratotomy using a Chiron ALK-E corneal shaper. Half of rabbits received acute amniotic membrane transplantation 30mn after chemical burn; the remaining five rabbits received medical treatment. In situ zymography is a recent nondestructive technique which preserved the fine morphological details of the cornea and showed the active enzyme location in different corneal layers. The MMP-2 and -9 substrate was gelatin, which was detected by fluorescent microscopy. RESULTS: There was an overexpression of MMP-2 and -9 in corneal burns versus control corneas. Expression of MMP-2 and -9 was low in corneal burn without amniotic membrane graft. Following amniotic membrane transplantation, MMP-2 and -9 were strongly expressed and clinical neovascularization and inflammation decreased. Active enzymes were located in epithelium layers in the uncovered group. In the covered group, the active enzymes were located in the anterior and posterior stromal layers. CONCLUSION: The results support a role for MMP-2 and MMP-9 in corneal burn neovascularization. Amniotic membrane transplantation can play a protective role by up-regulation of their biological expression.


Subject(s)
Amnion/transplantation , Cornea/blood supply , Eye Burns/enzymology , Eye Burns/surgery , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Animals , Burns, Chemical , Collagenases/metabolism , Disease Models, Animal , Gelatinases/metabolism , Humans , Neovascularization, Physiologic , Rabbits , Transplantation, Heterologous
6.
J Fr Ophtalmol ; 24(6): 597-602, 2001 Jun.
Article in French | MEDLINE | ID: mdl-11460055

ABSTRACT

PURPOSE: To investigate the prevalence of microbial keratitis, predisposing risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome in patients who developed microbial keratitis following penetrating keratoplasty (PK). MATERIAL: and methods: We reviewed 16 cases (15 patients) of microbial keratitis after PK. In all cases, corneal scrapings were obtained and microbiologically analyzed. Efficacy of treatment was evaluated by anatomical (clarity of graft) and visual recovery. RESULTS: Principal indications for PK were pseudophakic bullous keratopathy (50%) and microbial keratitis in the previous graft (25%). Sixty-three per cent of infections occurred within 1 year of PK. Principal predisposing risk factors were suture-related problems (44%) and microbial keratitis in the previous graft (25%). All of the scrapings were positive according to the microbiological evaluation with gram-positive cocci (64%), gram-positive rods (12%), fungi (18%), and Acanthamoeba (6%). We found 1 case of polymicrobial infection. Best visual and anatomical results were observed in nonadvanced cases and/or these treated early. After medical and surgical treatments, 8 patients (50%) had a clear graft and 10 patients (63%) had visual acuity less than 20/200. CONCLUSION: Postoperative control of risk factors and early recognition of infectious complications may decrease the incidence of severe microbial keratitis after PK.


Subject(s)
Acanthamoeba Keratitis/epidemiology , Eye Infections, Bacterial/epidemiology , Eye Infections, Fungal/epidemiology , Keratitis/epidemiology , Keratoplasty, Penetrating/statistics & numerical data , Postoperative Complications , Acanthamoeba Keratitis/diagnosis , Adult , Aged , Aged, 80 and over , Cornea/microbiology , Cornea/parasitology , Eye Infections, Bacterial/diagnosis , Eye Infections, Fungal/diagnosis , Female , Humans , Keratitis/diagnosis , Keratoplasty, Penetrating/adverse effects , Male , Middle Aged , Retrospective Studies , Risk Factors
7.
Pathol Biol (Paris) ; 49(4): 298-304, 2001 May.
Article in English | MEDLINE | ID: mdl-11428165

ABSTRACT

Blood-brain barrier (BBB) is the site of regulatory mechanisms which control the exchange of substances between the brain and the blood through the wall of 'true' brain capillaries with tight junctions between endothelial cells. In some pathological situations the permeability of the BBB is increased because of a partial proteolytic degradation of some constituents of the capillary basement lamina. In such cases it is important to restore normal permeability. The effect of procyanidolic oligomers (PCO) on the BBB was investigated in vivo with quantitative morphologic procedures. We also investigated the action of this drug on collagen and basement lamina constituents (Matrigel) in vitro. Collagenase injected in lateral brain ventricles was shown to increase BBB permeability. Per os administration of PCO to rats greatly increased the resistance of brain capillaries to bacterial collagenase, as shown by the inhibition of the diffusion of fluorescein-isothiocyanate-marked dextran particles from the blood-stream into the brain tissues. Calf skin collagen pretreated in vitro with PCO became more resistant to the hydrolytic action of collagenase. Similar, even more intense protective effect was seen when basal lamina constituents containing type IV collagen was incubated with PCO before exposure to pronase. These in vitro effects may partly explain the in vivo protective effect of PCO against the alteration of brain capillaries by i.v. injected bacterial collagenase.


Subject(s)
Biflavonoids , Blood-Brain Barrier/drug effects , Capillary Permeability/drug effects , Catechin/pharmacology , Proanthocyanidins , Animals , Capillary Resistance/drug effects , Collagen/metabolism , Collagenases/metabolism , Dextrans/metabolism , Drug Combinations , Fluorescein-5-isothiocyanate/analogs & derivatives , Fluorescein-5-isothiocyanate/metabolism , Laminin/metabolism , Male , Pronase/metabolism , Proteoglycans/metabolism , Rats , Rats, Wistar
8.
J Fr Ophtalmol ; 22(5): 545-8, 1999 May.
Article in French | MEDLINE | ID: mdl-10417914

ABSTRACT

PURPOSE: Trabeculectomy is an efficient procedure for congenital glaucoma, but can lead to postoperative complications. These complications seem to be less frequent with deep sclerectomy. The aim of this study is to evaluate results of this surgical technique for congenital glaucoma. MATERIALS AND METHODS: Twelve eyes from eight patients (age 2 to 84 months) with congenital glaucoma underwent sclerectomy and were followed-up for 10 months postoperatively. Success criteria was intraocular pressure inferior to 16 mm Hg under general anaesthesia. RESULTS: No per or immediate postoperative complication was observed. For nine eyes (75%), intraocular pressure was controlled at final examination. For three eyes, postoperative intraocular pressure was elevated and one of them underwent re-operation. CONCLUSIONS: Success rate of sclerectomy for congenital glaucoma is equivalent to trabeculectomy. Absence of anterior chamber opening diminishes postoperative complications risk. Further study with longer follow-up is currently under evaluation.


Subject(s)
Glaucoma/congenital , Sclera/surgery , Anesthesia, General , Child , Child, Preschool , Follow-Up Studies , Glaucoma/surgery , Humans , Infant , Intraocular Pressure , Ocular Hypertension/etiology , Ocular Hypertension/surgery , Postoperative Complications , Reoperation , Trabeculectomy , Treatment Outcome
10.
Biochem J ; 330 ( Pt 3): 1383-90, 1998 Mar 15.
Article in English | MEDLINE | ID: mdl-9494110

ABSTRACT

The leucoyte surface antigen CD38 has been shown to be an ecto-enzyme with multiple catalytic activities. It is principally a NAD+ glycohydrolase that transforms NAD+ into ADP-ribose and nicotinamide. CD38 is also able to produce small amounts of cyclic ADP-ribose (ADP-ribosyl cyclase activity) and to hydrolyse this cyclic metabolite into ADP-ribose (cyclic ADP-ribose hydrolase activity). To classify CD38 among the enzymes that transfer the ADP-ribosyl moiety of NAD+ to a variety of acceptors, we have investigated its substrate specificity and some characteristics of its kinetic and molecular mechanisms. We find that CD38-catalysed cleavage of the nicotinamide-ribose bond results in the formation of an E.ADP-ribosyl intermediary complex, which is common to all reaction pathways; this intermediate reacts (1) with acceptors such as water (hydrolysis), methanol (methanolysis) or pyridine (transglycosidation), and (2) intramolecularly, yielding cyclic ADP-ribose with a low efficiency. This reaction scheme is also followed when using nicotinamide guanine dinucleotide as an alternative substrate; in this case, however, the cyclization process is highly favoured. The results obtained here are not compatible with the prevailing model for the mode of action of CD38, according to which this enzyme produces first cyclic ADP-ribose which is then immediately hydrolysed into ADP-ribose (i.e. sequential ADP-ribosyl cyclase and cyclic ADP-ribose hydrolase activities). We show instead that the cyclic metabolite was a reaction product of CD38 rather than an obligatory reaction intermediate during the glycohydrolase activity. Altogether our results lead to the conclusion that CD38 is an authentic 'classical' NAD(P)+ glycohydrolase (EC 3.2.2.6).


Subject(s)
Antigens, CD/metabolism , Antigens, Differentiation/metabolism , NAD+ Nucleosidase/metabolism , ADP-ribosyl Cyclase , ADP-ribosyl Cyclase 1 , Antigens, CD/isolation & purification , Antigens, Differentiation/isolation & purification , Catalysis , Chromatography, Affinity , Chromatography, High Pressure Liquid , Humans , Kinetics , Membrane Glycoproteins , Multienzyme Complexes/metabolism , NAD+ Nucleosidase/isolation & purification , Substrate Specificity , Tumor Cells, Cultured
11.
J Immunol ; 157(4): 1381-8, 1996 Aug 15.
Article in English | MEDLINE | ID: mdl-8759717

ABSTRACT

The human leukocyte surface Ag CD38 was recently identified as a nicotinamide adenine dinucleotide (NAD)(+)-glycohydrolase ecto-enzyme, degrading NAD into nicotinamide and ADP-ribose. We show here that expression of CD38 is increased in the Jurkat T cell line after treatment with agents that augment intracellular cAMP, with the permeant cAMP analogue dibutyryl-cAMP (db-cAMP), and also with PMA, which activates protein kinase C. Treatment of human PBL T cells with db-cAMP or submitogenic doses of PMA also increased CD38 expression. Two other nucleotide-hydrolyzing activities were induced on the T cell surface concomitantly with CD38: the human PC-1 molecule, a nucleotide phosphodiesterase/pyrophosphatase that produces AMP from NAD or ADP-ribose, and a nucleotidase that produces adenosine from AMP, but which may be distinct from the CD73 5'-nucleotidase. All three enzymes were up-regulated after stimulation of human peripheral blood T cells with PHA. The coordinated regulation of these ecto-enzymes suggested that, besides a possible signaling function, they may recycle extracellular NAD by degrading it to adenosine and nicotinamide, which can be taken up by cells. In support of this hypothesis, db-cAMP-treated Jurkat cells could degrade extracellular NAD for de novo synthesis of purines, while untreated cells could not. Activated lymphocytes are often located in tissues in which cell death is common. It is suggested that the coordinated expression of these enzymes may allow activated T cells to re-use NAD and nucleotides from dead cells.


Subject(s)
Antigens, CD , Antigens, Differentiation/metabolism , Membrane Glycoproteins/metabolism , N-Glycosyl Hydrolases/metabolism , NAD+ Nucleosidase/metabolism , Nucleotides/metabolism , Phosphoric Diester Hydrolases , Pyrophosphatases , T-Lymphocyte Subsets/enzymology , ADP-ribosyl Cyclase , ADP-ribosyl Cyclase 1 , Azaserine/pharmacology , Base Sequence , Humans , Leukemia-Lymphoma, Adult T-Cell/pathology , Molecular Sequence Data , NAD/metabolism , Neoplasm Proteins/metabolism , RNA, Messenger/metabolism , Tumor Cells, Cultured
12.
J Periodontal Res ; 30(1): 58-65, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7722847

ABSTRACT

An elastin peptide (kE57) obtained from organoalkaline hydrolysis of calf ligamentum nuchae insoluble elastin, was isolated by gel permeation on Sephadex G150 and high performance liquid chromatography on a TSK G 3000 SW column. It possessed an average Mr = 57,000 and similar amino acids composition as its insoluble counterpart. kE57 behave as a competitive inhibitor of human neutrophil elastase (HNE) with Ki = 1.4 microM; it also inhibited porcine pancreatic elastase (PPE) but less efficiently Ki = 180 microM. Identification of elastic fibres in rat gingiva was ascertained by light and electron microscopic studies. Morphometric studies indicated that rat gingiva contained similar levels of elastic fibres (= 2%) as human skin; elastic fibres networks from both tissues also displayed high structural analogy. Gingival chronic inflammation was induced in rats by mechanical impaction associated with an hyperglucidic diet. After 5 weeks, the levels of rat gingiva elastic fibres, decreased from Vv = 1.94 +/- 0.1% to Vv = 1.02 +/- 0.06%. Local injections of kE57: 100 micrograms per day, 5 days a week for 5 weeks did restore the integrity of the gingiva elastic fibres network: Vv = 1.84 +/- 0.1. Without influencing leucocyte infiltration, it is proposed that elastin-derived peptides, acting as potent competitive inhibitor of neutrophil elastase involved in periodontitis, might be of therapeutic value.


Subject(s)
Elastic Tissue/metabolism , Elastin/pharmacology , Gingivitis/metabolism , Pancreatic Elastase/antagonists & inhibitors , Animals , Cattle , Chronic Disease , Connective Tissue/metabolism , Connective Tissue/pathology , Disease Models, Animal , Elastic Tissue/pathology , Elastin/isolation & purification , Gingivitis/enzymology , Gingivitis/pathology , Humans , Leukocyte Elastase , Pancreatic Elastase/metabolism , Peptide Fragments/isolation & purification , Peptide Fragments/pharmacology , Rats , Swine
13.
Pathol Biol (Paris) ; 40(9): 879-82, 1992 Nov.
Article in French | MEDLINE | ID: mdl-1296160

ABSTRACT

Effects of elastin peptides on elastase activity of gingival biopsy specimen extracts were studied in vitro and in vivo. All the extracts from biopsy specimens from 15 patients with a variety of periodontal diseases demonstrated fairly marked elastase activity. In vitro, addition of elastin peptides produced a mean inhibition of 54% +/- 14% with a concentration of 0.25 mg/ml and a mean inhibition of 90% +/- 6% with 2.5 mg/ml. In vivo treatment of gums with a paste containing 1% elastin peptides reduced elastase activity by 47% in 7 of 8 patients. These data suggest that elastin peptides are effective inhibitors of periodontal elastase activity and may be useful in preparations used for the preventive or curative treatment of periodontal diseases with tissue lysis.


Subject(s)
Elastin/pharmacology , Gingiva/drug effects , Pancreatic Elastase/antagonists & inhibitors , Peptides/pharmacology , Adolescent , Adult , Biopsy , Enzyme Inhibitors , Female , Gingiva/enzymology , Gingiva/metabolism , Gingival Crevicular Fluid/metabolism , Humans , In Vitro Techniques , Male , Middle Aged
14.
Cell Biochem Funct ; 9(3): 171-82, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1721559

ABSTRACT

3H-Labelled kappa-elastin peptides (kE:75 kDa molecular weight) were shown to bind to confluent human skin fibroblast (HSF) cultures in a time-dependent and saturable manner. Scatchard analysis indicated the presence of high affinity binding sites with kD = 2.7 x 10(-10) M and 19,000 sites per cell. Binding of kE to its receptor on HSF accelerates and intensifies the adhesion of insoluble elastin fibres (iE) to confluent HSF. Optimal effect was attained for a kE concentration of 0.3 x 10(-9) M close to kD. This stimulatory effect of kE on the binding of iE to HSF could be inhibited by neomycin, retinal and pertussis toxin, substances which act at different levels of the transduction mechanism following the activation of the receptor and the subsequent triggering of cell biological events (chemotaxis, modification of calcium fluxes). The stimulation of iE adhesion to HSF induced by kE as well as kE binding to the cells could be inhibited by lactose and laminin but not by Arg-Gly-Asp-Ser(RGDS) peptides. This indicates that the elastin peptide receptor on HSF possesses lectin-like properties and shares homology with the laminin receptor as also shown for other cell types. None of the substances tested, that is inhibitors of the transduction mechanism, lactose, laminin and Arg-Gly-Asp-Ser(RGDS) peptides were shown to interfere significantly with the binding of iE (in the absence of added kE) to confluent HSF. The proteins adhering strongly to elastin fibres were isolated by a sequential extraction procedure and the final hydrochloride guanidinium-DTT extract was analysed by SDS-PAGE under reducing conditions, Western blots using specific antibodies against several connective tissue proteins and affinity for [3H]-kE following nitrocellulose electro-transfer of proteins. Fibronectin, vitronectin, tropoelastin(s), and a 120 kDa cysteine rich glycoprotein previously designated as elastonectin were identified. Among these proteins, [3H]-kE was found to bind exclusively to a 65 kDa protein that could be eluted selectively from elastin fibres with a neutral buffer containing 100 mM lactose. Therefore the elastin peptide receptor on human skin fibroblasts shares properties with the elastin receptor characterized from other cell types. Conformational differences between elastin peptides and elastin fibres could explain the differences in the mechanisms of interactions between elastin fibres and elastin peptides with HSF in culture. The stimulatory effect of elastin-derived peptides on the adhesion of elastin fibres to HSF could have implications in the oriented biosynthesis of elastin fibres.


Subject(s)
Binding Sites/physiology , Elastin/metabolism , Extracellular Matrix/chemistry , Fibroblasts/metabolism , Receptors, Cell Surface/metabolism , Adult , Amino Acid Sequence , Extracellular Matrix/metabolism , Female , Fibroblasts/cytology , Fibronectins/metabolism , Glycoproteins/metabolism , Humans , Molecular Sequence Data , Oligopeptides/metabolism , Platelet Aggregation Inhibitors/metabolism , Skin/cytology , Tropoelastin/metabolism , Vitronectin
15.
J Cancer Res Clin Oncol ; 117(3): 232-8, 1991.
Article in English | MEDLINE | ID: mdl-1851764

ABSTRACT

Interactions between the extracellular matrix macromolecules and tumor cells are critical in the process of metastasis formation. We show here that elastins (both mature insoluble elastin and a 75-kDa soluble peptide: K-elastin) adhere rapidly to two cell lines with high metastatic capacities: a metastatic lung carcinoma cell line (3LL-HM) and a human amelanotic melanoma cell line (A-2058); by contrast the low-metastatic Lewis lung carcinoma cell line variant as well as a rhabdomyosarcoma cell line with a low metastatic potential bind to elastins to a much lower extent. 3H-labelled K-elastin was used in order to study elastin--3LL-HM interaction. It was found to be saturable (2 ng 3H-labelled K-elastin/10(6) cells), with one class of high-affinity binding sites having Kd equal to 1.3 nM and 16,000 sites/cell. The binding of K-elastin to 3LL-HM cells at its receptor triggered several cell responses; (a) increase of intracellular Ca2+ concentration; (b) induction of 3LL-HM chemotaxis toward the K-elastin gradient; (c) stimulation of the adherence of mature insoluble elastin. In contrast to non-transformed cells such as fibroblasts and smooth muscle cells, the adhesion kinetics of insoluble elastin to 3LL-HM did not exhibit a lag period; the rapid binding of insoluble elastin to the tumor cells was followed by its slow detachment from the cells, which lasted for 6 h. 3LL-HM cells but not human skin fibroblasts were shown to secrete elastinolytic activity inhibitable by metal-chelating agents. In vivo studies were performed in order to evaluate the influence of K-elastin binding to 3LL-HM cells on their ability to form lung colonies in mice. It was shown that pretreatment of 10(4) 3LL-HM cells with 10 microM K-elastin and the simultaneous i.v. injection into mice of 750 micrograms K-elastin together with the highly metastatic cells was able to reduce the number of lung colonies by more than 70% after 12 days.


Subject(s)
Elastin/metabolism , Tumor Cells, Cultured/metabolism , Adult , Amino Acid Sequence , Animals , Cell Adhesion , Chemotaxis , Elastin/administration & dosage , Elastin/pharmacology , Female , Fibroblasts/enzymology , Fibroblasts/metabolism , Humans , Kinetics , Lung Neoplasms/metabolism , Mice , Mice, Nude , Molecular Sequence Data , Neoplasm Metastasis , Pancreatic Elastase/metabolism , Receptors, Cell Surface/metabolism , Tumor Cells, Cultured/enzymology
16.
J Invest Dermatol ; 91(5): 472-7, 1988 Nov.
Article in English | MEDLINE | ID: mdl-3049835

ABSTRACT

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.


Subject(s)
Fibroblasts/enzymology , Pancreatic Elastase/metabolism , Skin/cytology , Adult , Cell Fractionation , Copper , Elastin/metabolism , Female , Humans , Hydrolysis , Leucine/analogs & derivatives , Leucyl Aminopeptidase/antagonists & inhibitors , Leucyl Aminopeptidase/metabolism , Pancreatic Elastase/antagonists & inhibitors , Peptide Hydrolases , Skin/enzymology , Substrate Specificity , Zinc
17.
Biochem J ; 252(2): 515-9, 1988 Jun 01.
Article in English | MEDLINE | ID: mdl-3415672

ABSTRACT

Leucocyte proteinases, e.g. leucocyte elastase and cathepsin G, are inhibited by heparin. The activities of pig pancreatic and Pseudomonas aeruginosa elastases are unaffected by this polysaccharide. Heparin derivatives of known Mr and degree of sulphation were isolated. The inhibition of leucocyte elastase by these oligosaccharides can be classified as tight-binding hyperbolic non-competitive. Ki values ranged from 40 nM to 100 microM and were found to be inversely correlated with the chain length of the oligosaccharides. Desulphated compounds lacked inhibitory potential towards leucocyte elastase. Over-O-sulphated di- and tetra-saccharides are more potent inhibitors than their over-N-sulphated counterparts. It is proposed that the therapeutic use of heparin and its derivatives could be extended to disease states such as emphysema and rheumatoid arthritis, where the role of leucocyte elastase has been clearly established.


Subject(s)
Heparin/analogs & derivatives , Heparin/pharmacology , Leukocytes/enzymology , Pancreatic Elastase/antagonists & inhibitors , Animals , Kinetics , Leukocyte Elastase , Oligopeptides/metabolism , Oligosaccharides/pharmacology , Protease Inhibitors/pharmacology , Rats , Structure-Activity Relationship
18.
Exp Mol Pathol ; 46(3): 345-56, 1987 Jun.
Article in English | MEDLINE | ID: mdl-2439369

ABSTRACT

Immunization of rabbits with elastin peptides prepared from purified bovine ligamentum nuchae elastin produces calcified arteriosclerotic lesions and fragmentation of elastic lamellae. Simultaneous administration of porcine calcitonin largely prevents the development of lesions. Experiments were carried out to clarify the mechanisms involved in the development of lesions as well as those involved in the preventive effect of calcitonin. Control experiments were carried out using bovine serum albumin (BSA) as antigen. Circulating antibodies and soluble immune complexes increased steadily in the sera of animals immunized with elastin peptides or BSA. The cellular immune reaction was weak as assessed by [3H]thymidine incorporation into lymphocytes in the presence of antigen or phytohemagglutinin. Arterial lesions appeared only in the animals immunized with elastin peptides, not in those immunized with BSA. Ion flux measurements were also carried out on strips of aorta obtained from immunized and control animals. Immunization with elastin peptides significantly increased the ouabain-insensitive 22Na+ efflux, the 86Rb efflux (indicator of K+ efflux), and the 45Ca2+ influx. Simultaneous calcitonin administration prevented the increase in Ca2+ influx but did enhance passive permeability to Na+ and K+ as well as the sodium pump. When calcitonin was administered without immunization, it decreased arterial smooth muscle permeability to Na+ and K+ and also decreased the basal Ca2+ influx. It is concluded that the pathological modifications of the arterial wall triggered by immunization with elastin peptides is at least partly mediated by the effect of antielastin antibodies and immune complexes on the ion permeability of arterial smooth muscle. Prevention of the increased Ca2+ influx by calcitonin is probably a key effect in the prevention of the development of lesions. The fact that calcitonin alone can modify the ion permeability of arterial smooth muscle suggests that this hormone may play a role in the regulation of vascular homeostasis.


Subject(s)
Arteriosclerosis/metabolism , Calcitonin/pharmacology , Elastin/immunology , Immunization , Ion Channels/metabolism , Muscle, Smooth, Vascular/metabolism , Animals , Antigen-Antibody Complex/analysis , Aorta/metabolism , Aorta/pathology , Arteriosclerosis/immunology , Arteriosclerosis/pathology , Cell Membrane Permeability , Immunity, Cellular , Ion Channels/drug effects , Male , Muscle, Smooth, Vascular/pathology , Rabbits , Serum Albumin, Bovine/immunology
19.
Cell Biochem Funct ; 5(2): 113-22, 1987 Apr.
Article in English | MEDLINE | ID: mdl-3495371

ABSTRACT

Rat leukocyte elastase has been purified successively by AH-Sepharose Kappa-elastin affinity chromatography and by ion exchange chromatography on a carboxymethyl Sephadex resin. It has great similarities with human leukocyte elastase in its molecular weight, substrate specificity and inhibitory profile. The effect of rat leukocyte elastase inhibitors in influencing the chemotactic response of rat PMN to fMetLeuPhe has been compared to that of other proteinase inhibitors. The results indicated that oleoyl (Ala)2ProValCH2Cl, a specific inhibitor of human and rat leukocyte elastases and Eglin C, which also inhibits human and rat cathepsin G, are among the powerful inhibitors of rat PMN chemotaxis induced by the formyl oligopeptide. This suggests that these neutral proteinases, in addition to their known participation in connective tissue catabolism, could play a role in PMN locomotion and chemotaxis.


Subject(s)
Chemotaxis, Leukocyte/drug effects , N-Formylmethionine Leucyl-Phenylalanine/antagonists & inhibitors , Pancreatic Elastase/antagonists & inhibitors , Serpins , Animals , Blood Proteins/pharmacology , In Vitro Techniques , Molecular Weight , Neutrophils/enzymology , Pancreatic Elastase/isolation & purification , Proteins/pharmacology , Rats , alpha 1-Antitrypsin
20.
Proc Natl Acad Sci U S A ; 83(15): 5517-20, 1986 Aug.
Article in English | MEDLINE | ID: mdl-3461447

ABSTRACT

The addition of highly purified elastic fibers to confluent human skin fibroblast or porcine aorta smooth muscle cell cultures resulted in a time-dependent, strong adhesion of the fibrils to the cell surface. The kinetics of adhesion was studied by video/time-lapse cinematography. After a 0.5-1 hr lag period, adhesion progressed to a maximum amount in 3-6 hr in the described conditions. Adhesion is strongly accelerated by the prior addition of soluble elastin peptides (kappa-elastin) to the cultures. Cycloheximide inhibits this induced adhesion. Adherent elastic fibers can be detached by treatment with elastase and trypsin but not with collagenase. The radioactive proteins adhering to elastic fibers, after a 6-hr incubation of the induced cultures in presence of [35S]methionine, were extracted and analyzed by NaDodSO4/PAGE. The proteins strongly adhering to the elastic fibers had apparent molecular sizes of about 120, 67, 60, and 45 kDa. Only the 120-kDa protein band showed a significant increase of its associated radioactivity in the induced cultures as compared to the noninduced cultures. We propose that the 120-kDa protein is responsible for the induced adhesion of mesenchymal cells to elastic fibers and designate it "elastonectin."


Subject(s)
Cell Adhesion , Elastin/physiology , Fibroblasts/cytology , Glycoproteins/metabolism , Muscle, Smooth, Vascular/cytology , Animals , Cattle , Cells, Cultured , Glycoproteins/isolation & purification , Humans , Molecular Weight , Swine
SELECTION OF CITATIONS
SEARCH DETAIL
...