RESUMO
Hev b 13 is an allergenic esterase obtained from the rubber tree Hevea brasiliensis, which has been shown recently to induce human mononuclear cells to release interleukin (IL)-10 in vitro. This immunoregulatory cytokine appears to play an important role in preventing inflammation and mucosal damage in animal models of colitis and in Crohn's disease patients. The aim of this study was to evaluate the therapeutic effect of Hev b 13 in mice with 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis. Two hours following colonic instillation of the haptenizing agent, and daily thereafter for 5 days, Hev b 13 was administered by oral gavage. In mice treated with daily doses of either 0·5 mg/kg or 5·0 mg/kg of Hev b 13, the clinical signs of diarrhoea, rectal prolapse and body weight loss and also histological damage of the distal colon, were reduced significantly, in comparison with water-treated diseased mice. These findings suggest a potent anti-inflammatory activity of Hev b 13; this activity is speculated to be related to its interaction with cells from the immune system.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Antígenos de Plantas/administração & dosagem , Colite/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Interleucina-10/imunologia , Proteínas de Plantas/administração & dosagem , Administração Oral , Animais , Colite/induzido quimicamente , Colite/prevenção & controle , Colo/efeitos dos fármacos , Diarreia/tratamento farmacológico , Feminino , Humanos , Interleucina-10/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Prolapso Retal/tratamento farmacológico , Ácido Trinitrobenzenossulfônico/efeitos adversos , Redução de Peso/efeitos dos fármacosRESUMO
The aim of the present study was to compare healing obtained with biomembranes with the natural healing process (sham) using biochemical and immunohistological assays. C57BL/6 mice were divided into 4 groups of 15 mice each and received different subcutaneous implants: natural latex biomembrane (NLB), denatured latex (DL), expanded polytetrafluorethylene (ePTFE), or sham. On the 2nd, 7th, and 14th days post-treatment, 5 mice per group were sacrificed and biopsied for the following measurements: oxidative stress based on malondialdehyde (MDA), myeloperoxidase (MPO) and hydrogen peroxide by the method of ferrous oxidation-xylenol orange (FOX), as well as glutathione and total proteins; histological evaluation to enumerate inflammatory cells, fibroblasts, blood vessels, and collagen, and immunohistochemical staining for inducible nitric oxide synthase, interleukin-1β, vascular endothelial growth factor (VEGF), and transforming growth factor-β1 (TGF-β1). On day 2 post-treatment, NLB stimulated a dense inflammatory infiltrate mainly consisting of polymorphonuclear cells, as indicated by increased MPO (P < 0.05), but oxidative stress due to MDA was not observed until the 7th day (P < 0.05). The number of blood vessels was greater in NLB (P < 0.05) and DL (P < 0.05) mice compared to sham animals on day 14. NLB induced fibroplasia by day 14 (P < 0.05) with low expression of TGF-β1 and collagenesis. Thus, NLB significantly induced the inflammatory phase of healing mediated by oxidative stress, which appeared to influence the subsequent phases such as angiogenesis (with low expression of VEGF) and fibroplasia (independent of TGF-β1) without influencing collagenesis.
Assuntos
Animais , Masculino , Camundongos , Materiais Biocompatíveis/uso terapêutico , Látex/uso terapêutico , Membranas Artificiais , Estresse Oxidativo/fisiologia , Politetrafluoretileno/uso terapêutico , Cicatrização/fisiologia , Imuno-Histoquímica , Inflamação/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Cicatrização/efeitos dos fármacosRESUMO
The aim of the present study was to compare healing obtained with biomembranes with the natural healing process (sham) using biochemical and immunohistological assays. C57BL/6 mice were divided into 4 groups of 15 mice each and received different subcutaneous implants: natural latex biomembrane (NLB), denatured latex (DL), expanded polytetrafluorethylene (ePTFE), or sham. On the 2nd, 7th, and 14th days post-treatment, 5 mice per group were sacrificed and biopsied for the following measurements: oxidative stress based on malondialdehyde (MDA), myeloperoxidase (MPO) and hydrogen peroxide by the method of ferrous oxidation-xylenol orange (FOX), as well as glutathione and total proteins; histological evaluation to enumerate inflammatory cells, fibroblasts, blood vessels, and collagen, and immunohistochemical staining for inducible nitric oxide synthase, interleukin-1ß, vascular endothelial growth factor (VEGF), and transforming growth factor-ß1 (TGF-ß1). On day 2 post-treatment, NLB stimulated a dense inflammatory infiltrate mainly consisting of polymorphonuclear cells, as indicated by increased MPO (P < 0.05), but oxidative stress due to MDA was not observed until the 7th day (P < 0.05). The number of blood vessels was greater in NLB (P < 0.05) and DL (P < 0.05) mice compared to sham animals on day 14. NLB induced fibroplasia by day 14 (P < 0.05) with low expression of TGF-ß1 and collagenesis. Thus, NLB significantly induced the inflammatory phase of healing mediated by oxidative stress, which appeared to influence the subsequent phases such as angiogenesis (with low expression of VEGF) and fibroplasia (independent of TGF-ß1) without influencing collagenesis.
Assuntos
Materiais Biocompatíveis/uso terapêutico , Látex/uso terapêutico , Membranas Artificiais , Estresse Oxidativo/fisiologia , Politetrafluoretileno/uso terapêutico , Cicatrização/fisiologia , Animais , Imuno-Histoquímica , Inflamação/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Cicatrização/efeitos dos fármacosRESUMO
PURPOSE: To describe the presence of iris neovascularization in a rabbit-model of retinal neovascularization induced by the intravitreal injection of latex-derived angiogenic fraction microspheres (LAF). MATERIALS AND METHODS: Eight New Zealand rabbits received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 50 ug of LAF in the right eye (Group A). Microspheres without the LAF (0.1 ml) were injected in controls (Group B; n = 8). Follow-up with clinical evaluation and iris fluorescein angiography was performed after 4 weeks when eyes were processed for light microscopy. RESULTS: All eyes from Group A showed significant vascular dilation, conjunctival hyperemia and neovascularization on the iris surface, after LAF injection. No vascular changes were observed in Group B. CONCLUSIONS: The intravitreal injection of microspheres containing the LAF can induce rubeosis iridis in rabbits and could be used as a simple experimental model for iris neovascularization.
Assuntos
Indutores da Angiogênese/toxicidade , Glaucoma Neovascular/etiologia , Iris/irrigação sanguínea , Látex/toxicidade , Neovascularização Patológica/induzido quimicamente , Indutores da Angiogênese/administração & dosagem , Animais , Modelos Animais de Doenças , Progressão da Doença , Portadores de Fármacos , Feminino , Angiofluoresceinografia , Fundo de Olho , Glaucoma Neovascular/patologia , Injeções Intravítreas , Iris/efeitos dos fármacos , Ácido Láctico , Látex/administração & dosagem , Microesferas , Neovascularização Patológica/complicações , Neovascularização Patológica/patologia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Fatores de RiscoRESUMO
PURPOSE: To create a retinal neovascularization experimental model using intravitreal injection of microspheres loaded with latex-derived angiogenic fraction. METHODS: Thirty-two albino New Zealand rabbits, divided in 4 groups of 8 animals, were enrolled in this study. Rabbits in groups I, II, and III received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 10, 30, and 50 microg of latex-derived angiogenic fraction into their right eyes, respectively, and group IV received 0.1 ml of microspheres without the angiogenic fraction. Weekly follow-up with ophthalmoscopy and fluorescein angiography was performed; the rabbits were sacrificed in the 4th week and their eyes processed for light microscopy. RESULTS: All eyes from group I demonstrated increased retinal vascular tortuosity, observed from 14 days after injection and maintained for 28 days, otherwise without new vessels detection. All group II eyes showed vascular changes similar to group I. Fifty percent of the eyes from group II rabbits developed retinal neovascularization 21 days after injection. All eyes from group III demonstrated significant vascular tortuosity and retinal new vessels 2 weeks after injection, progressing to fibrovascular proliferation and tractional retinal detachment. No vascular changes or retinal new vessels were observed in group IV eyes. Light microscopy confirmed the existence of new vessels previously seen on fluorescein angiography, in retinal sections adjacent to the optic disc, not observed in sections at the same area in the control group. CONCLUSION: Thirty- and 50-microg microspheres containing latex-derived angiogenic fraction injected into the vitreous cavity induced retinal neovascularization in rabbits.
Assuntos
Indutores da Angiogênese/toxicidade , Modelos Animais de Doenças , Látex/toxicidade , Neovascularização Retiniana/induzido quimicamente , Vasos Retinianos/efeitos dos fármacos , Animais , Portadores de Fármacos , Feminino , Angiofluoresceinografia , Ácido Láctico , Microesferas , Oftalmoscopia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Neovascularização Retiniana/diagnóstico , Vasos Retinianos/patologiaRESUMO
BACKGROUND AND PURPOSE: In this work, a neuroactive peptide from the venom of the neotropical wasp Polybia occidentalis was isolated and its anti-nociceptive effects were characterized in well-established pain induction models. EXPERIMENTAL APPROACH: Wasp venom was analysed by reverse-phase HPLC and fractions screened for anti-nociceptive activity. The structure of the most active fraction was identified by electron-spray mass spectrometry (ESI-MS/MS) and it was further assessed in two tests of anti-nociceptive activity in rats: the hot plate and tail flick tests. KEY RESULTS: The most active fraction contained a peptide whose structure was Arg-Pro-Pro-Gly-Phe-Thr-Pro-Phe-Arg-OH, which corresponds to that of Thr(6)-BK, a bradykinin analogue. This peptide was given by i.c.v. injection to rats. In the tail flick test, Thr(6)-BK induced anti-nociceptive effects, approximately twice as potent as either morphine or bradykinin also given i.c.v. The anti-nociceptive activity of Thr(6)-BK peaked at 30 min after injection and persisted for 2 h, longer than bradykinin. The primary mode of action of Thr(6)-BK involved the activation of B(2) bradykinin receptors, as anti-nociceptive effects of Thr(6)-BK were antagonized by a selective B(2) receptor antagonist. CONCLUSIONS AND IMPLICATIONS: Our data indicate that Thr(6)-BK acts through B(2) bradykinin receptors in the mammalian CNS, evoking antinociceptive behaviour. This activity is remarkably different from that of bradykinin, despite the structural similarities between both peptides. In addition, due to the increased metabolic stability of Thr(6)-BK, relative to that of bradykinin, this peptide could provide a novel tool in the investigation of kinin pathways involved with pain.
Assuntos
Analgésicos/farmacologia , Bradicinina/análogos & derivados , Dor/tratamento farmacológico , Venenos de Vespas/química , Analgésicos/administração & dosagem , Animais , Bradicinina/administração & dosagem , Bradicinina/isolamento & purificação , Bradicinina/farmacologia , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Injeções Intraventriculares , Sistema Calicreína-Cinina , Masculino , Morfina/administração & dosagem , Morfina/farmacologia , Dor/fisiopatologia , Medição da Dor , Ratos , Ratos Wistar , Receptor B2 da Bradicinina/efeitos dos fármacos , Receptor B2 da Bradicinina/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
In this communication, we show that the palB7 mutation drastically reduced the mannose and N-acetylgalactosamine content of the pacA-encoded acid phosphatase secreted by the fungus Aspergillus nidulans at pH 5.0, compared to a control strain. By using mRNA differential display reverse transcription and polymerase chain reaction, we isolated two cDNAs from the control pabaA1 strain that were not detected in the palB7 mutant strain that encode a mannosyl transferase and a NADH-ubiquinone oxidoreductase. Thus, a defect in the posttranslational mannosylation of proteins could be the consequence of mutations in the palB gene, which encodes for a nuclear calpain-like protease that may have specific functions in the processing of transcription factor(s) similar to its homolog, RIM13, in Saccharomyces cereviseae.
Assuntos
Cisteína Endopeptidases/genética , Proteínas Fúngicas , Manose/metabolismo , Mutação , Monoéster Fosfórico Hidrolases/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Sequência de Aminoácidos , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Cisteína Endopeptidases/metabolismo , Glicosilação , Temperatura Alta , Dados de Sequência MolecularRESUMO
Cerebral ischaemia is eventualy observed during neurosurgical procedures and in several clinical entities that may cause severe neurological deficits and even death. Because it is a severe and complex problem, several studies have been done aiming to elucidate the mechanisms of the ischemic phenomenon and aiming to abolish or to diminish its effects, using drugs that protect the neurons from ischaemia-induced damage. Several neurotransmitters play a role in cerebral ischaemia with emphasis to glutamate by its high concentration in the central nervous system. The purpose of this study was to evaluate the effect of focal cerebral ischaemia in the rat through the dosage of the glutamate and morphological findings, and to evaluate a possible protective effect of the ketoprofen to ischemic neurons. Thirty-six rats Wistar were divided into four groups. The first was a control group, the second a sham group and the animals of the third and fourth groups were submitted to induced cerebral ischaemia through selective obstruction of the midlle cerebral artery during 15, 30 and 45 minutes. Animals of the fourth group were previously treated with ketoprofen 15 minutes before the ischaemia. The ischaemia was evaluated through the histopathological examination and through dosage of the extracellular glutamate in vitro. The histopathological examination showed that there was no difference between the animals of the control and of the sham groups. In the animals submitted to ischemia histopathological alterations appeared at 30 minutes and become more intense at 45 minutes of ischaemia. The main findings were interstitial edema, chromatinic disorganization, vacuolization and nuclear desintegration. The animals treated with ketoprofen showed similar alterations, but they were less intense. Decrease in the dosage of glutamate in the parietal cortex of the animals submitted to ischaemia started at 30 minutes and became more intense at 45 minutes of ischaemia and was similar for animals previously treated or not with ketoprofen, indicating that this drug seems not to interfere with the metabolism of the glutamate at the synapses. The morphological findings in the parietal cortex of the animals submitted to ischaemia, previously treated or not with ketoprofen, suggest that this drug has a neuroprotective effect.
Assuntos
Arteriopatias Oclusivas/complicações , Isquemia Encefálica/tratamento farmacológico , Inibidores de Ciclo-Oxigenase/uso terapêutico , Ácido Glutâmico/análise , Cetoprofeno/uso terapêutico , Artéria Cerebral Média , Animais , Arteriopatias Oclusivas/patologia , Isquemia Encefálica/etiologia , Isquemia Encefálica/patologia , Estudos de Casos e Controles , Artéria Cerebral Média/efeitos dos fármacos , Artéria Cerebral Média/patologia , Ratos , Ratos Wistar , Estatísticas não ParamétricasRESUMO
BACKGROUND: Oxygen free radicals are considered to be important components involved in the physiopathological tissue alterations observed during ischemia and reperfusion. The objective of the present study was to investigate oxidative stress based on indicators of oxygen free radical activity and on the changes in behavior of the lipoprotein membrane (O-phosphoserine) in the skeletal muscle of rats. MATERIAL AND METHODS: Twenty Wistar rats were divided into two groups of 10. One group was submitted to 3 h of total ischemia by applying a tourniquet to the hind limb and the contralateral hind limb was used as control. The second group was submitted to the same procedure and was reperfused for 45 min after 3 h of ischemia by removing the tourniquet, where the contralateral hind limb of the same animal was used as control. Muscle biopsies were taken after ischemia and reperfusion and the parameters indicating oxidative stress (reduced and oxidized glutathione, malondialdehyde, glutamine synthetase, protein carbonyl) and O-phosphoserine (OPS) alterations were analyzed. RESULTS: The following results display control versus experimental hindlimbs groups obtained from the same animal. The skeletal muscle of rats submitted to total ischemia of 3 h duration showed increased OPS release (2.69 +/- 4.52 vs 8.03 +/- 7.20; n = 10; P = 0.024) and no change in reduced and oxidized glutathione, glutamine synthetase, protein carbonyl, or malondialdehyde. After 45 min of reperfusion there was an increase in oxidized glutathione levels (0.30 +/- 0.06 vs 0.39 +/- 0.09; n = 8; P = 0.02) and malondialdehyde levels (154. 78 +/- 26.13 vs 206.30 +/- 47.30; n = 9; P = 0.008), a fall in glutamine synthetase (21.80 +/- 3.61 vs 13.52 +/- 6.78; n = 9; P = 0. 004), and a return of OPS to levels close to the initial ones. No changes in reduced glutathione or protein carbonyl were observed in the two groups studied. CONCLUSIONS: After a total ischemia duration of 3 h there were signs of damage to the phospholipid membrane of the rat skeletal muscle, as demonstrated by the elevation of OPS and the few or no oxidative changes in the cell. After 45 min of reperfusion, oxidative damage to the lipoprotein components of the cell membrane was observed, characterized by elevations of oxidized glutathione and malondialdehyde levels and a fall in glutamine synthetase levels.
Assuntos
Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Membrana Celular/enzimologia , Membro Posterior/irrigação sanguínea , Masculino , Músculo Esquelético/irrigação sanguínea , Fosfolipases/metabolismo , Fosfolipídeos/metabolismo , Ratos , Ratos WistarRESUMO
Spider venoms have high specificity to neuronal elements. Therefore, the use of venom has been important in the characterisation of mammal and insect nervous systems. The evaluation of insect paralysis has been an important tool for distinguishing the biological effects of venom. In this study we describe the paralysing effect of a spider crude venom (Parawixia bistriata) in termites, utilising a new bioassay. The crude venom of P. bistriata caused an irreversible and dose-dependent paralysis in the animals in the following doses: 2.10(-5) U; 2.10(-4) U; 2.10(-3) U; 2.10(-2) U and 0.12 U (1 U = 1 gland). This bioassay will allow for easy and direct evaluation of biological effects from different venoms and purified fractions.