Résumé
PURPOSE: To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant. METHODS: A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively). RESULTS: Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2. CONCLUSION: The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant. .
Sujets)
Animaux , Cochons d'Inde , Mâle , Implant résorbable , Oreille moyenne/effets des médicaments et des substances chimiques , Lactates/usage thérapeutique , Polymères/usage thérapeutique , Acide lipoïque/analogues et dérivés , Biopolymères/usage thérapeutique , Exsudats et transsudats , Oreille moyenne/anatomopathologie , Fibroblastes/effets des médicaments et des substances chimiques , Muqueuse/effets des médicaments et des substances chimiques , Muqueuse/anatomopathologie , Néovascularisation pathologique , Granulocytes neutrophiles/effets des médicaments et des substances chimiques , Répartition aléatoire , Reproductibilité des résultats , Facteurs temps , Acide lipoïque/usage thérapeutiqueRésumé
Dihydrolipoamide dehydrogenase (LADH) from Trypanosoma cruzi, the causative agent of Chagas' disease, was inactivated by treatment with myeloperoxidase (MPO)-dependent systems. LADH lipoamide reductase and diaphorase activities decreased as a function of incubation time and composition of the MPO/H2O2/halide system, a transient increase preceding the loss of diaphorase activity. Iodide, bromide, thiocyanide and chloride were effective components of MPO/H2O2 or MPO/NADH systems. Catalase prevented LADH inactivation by the MPO/NADH/halide systems in agreement with H2O2 production by NADH-supplemented LADH. Thiol compounds (L-cysteine, N-acetylcysteine, penicillamine, N-(2-mercaptopropionylglycine) and Captopril prevented LADH inactivation by the MPO/H2O2/NaCl system and by NaOCl, thus supporting HOCl as agent of the MPO/H2O2/NaCl system. MPO/H2O2/NaNO2 and MPO/NADH/NaNO2 inactivated LADH, the reaction being prevented by MPO inhibitors and thiol compounds. T. cruzi LADH was affected by MPO-dependent systems like myocardial LADH, allowance being made for the variation of the diaphorase activity and the greater sensitivity of the T. cruzi enzyme to MPO/H2O2/halide systems.
Sujets)
Animaux , Humains , Acide hypochloreux/pharmacologie , Dihydrolipoamide dehydrogenase , Granulocytes neutrophiles/physiologie , Nitrites , Myeloperoxidase , Protéines de protozoaire/antagonistes et inhibiteurs , Stimulation du métabolisme oxydatif , Trypanosoma cruzi , Acétylcystéine/pharmacologie , Acide lipoïque/analogues et dérivés , Acide lipoïque/métabolisme , Bromures , Captopril , Catalase , Cystéine/pharmacologie , Chlorure de sodium/pharmacologie , Composés du sodium/pharmacologie , Cytotoxicité immunologique , Espèces réactives de l'oxygène/métabolisme , Glutathion , Glycine , Cinétique , Myocarde , NAD , Granulocytes neutrophiles/enzymologie , Oxydoréduction , Pénicillamine , Peroxyde d'hydrogène/pharmacologie , Protéines recombinantes/antagonistes et inhibiteurs , Thiols , Tryptophane , TyrosineRésumé
Comparative detoxification of scorpion venom by using different chemical agents was investigated. Detoxification by formalin showed the best optimum detoxifying agent. The formalin treatment resulted in 2.3% protein loss with 6-fold detoxification. This formal toxoid was immunogenic in rabbit giving high neutralizing antibodies as revealed from indirect haemagglutination test. Toxoid antiserum protected mice against the lethal action of venom. It also effectively antagonized the smooth muscle contractile response of venom, and venom-induced neuromuscular paralysis. This toxoid antiserum also protected the venom-induced cardiac arrest. The possibility of using this formal toxoid for antisera production and immunization for therapeutic use needs to be explored.