Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
ESMO Open ; 9(9): 103689, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39265219

RESUMO

BACKGROUND: To present findings from a retrospective study conducted by the Ultra-Rare Sarcoma Working Group on metastatic low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), and hybrid (H)-LGFMS/SEF across 28 global centres. METHODS: Patients treated at participating institutions from January 2000 to September 2022 were retrospectively selected. Diagnosis was confirmed by expert pathologists. Primary endpoint was progression-free survival (PFS-1) from metastasis detection to first progression or death. PFS-2 was calculated from therapy initiation. RESULTS: A total of 101 patients were identified (32 LGFMS, 50 SEF, 19 H-LGFMS/SEF). Median (m) follow-up was 62.1 months. mPFS-1 was 28.7, 11.8, and 20.3 months for LGFMS, SEF, and H-LGFMS/SEF, respectively. mOS was 145.8, 41.9, and 113.5 months, respectively. Treatments included anthracycline-based chemotherapy, gemcitabine-based chemotherapy (G), pazopanib, trabectedin, others. mPFS-2 was: 20.1, 5.5, and 3.5 months in H-LGFMS/SEF, SEF, and LGFMS, respectively, with anthracyclines; 19.5, 7.7, and 6.9 months in LGFMS, SEF, and H-LGFMS/SEF, respectively, with pazopanib; 12.0, 9.7, and 3.1 months in H-LGFMS/SEF, LGFMS, and SEF, respectively. Occasional responses occurred with ifosfamide/oral cyclophosphamide, and prolonged stable disease with immune checkpoint inhibitors. CONCLUSIONS: In this series, the largest available, metastatic LGFMS, SEF, and H-LGFMS/SEF showed different courses. Systemic agents have modest efficacy, informing future trials of novel agents for these tumours.


Assuntos
Fibrossarcoma , Humanos , Estudos Retrospectivos , Feminino , Masculino , Fibrossarcoma/tratamento farmacológico , Pessoa de Meia-Idade , Adulto , Idoso , Adulto Jovem , Pirimidinas/uso terapêutico , Indazóis/uso terapêutico , Gencitabina , Trabectedina/uso terapêutico , Adolescente , Sulfonamidas/uso terapêutico , Gradação de Tumores , Antraciclinas/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecidos Moles/patologia
2.
ESMO Open ; 7(4): 100536, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35849879

RESUMO

Immune checkpoint inhibitors (ICIs) have completely reshaped the treatment of many malignancies, with remarkable improvements in survival outcomes. In ovarian cancer (OC), however, this emerging class of drugs has not yet found a favorable use due to results from phase I and II studies, which have not suggested a substantial antitumoral activity of these agents when administered as monotherapy. Robust preclinical data seem to suggest that the combination ICIs with poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) may result in a synergistic activity; furthermore, data from phase II clinical studies, evaluating this combination, have shown encouraging outcomes especially for those OC patients not suitable for platinum retreatment. While waiting for ongoing phase III clinical trial results, which will clarify the role of ICIs in combination with PARPis in the newly diagnosed OC, this review aims to summarize the preclinical data and clinical evidence available to date.


Assuntos
Neoplasias Ovarianas , Inibidores de Poli(ADP-Ribose) Polimerases , Feminino , Humanos , Inibidores de Checkpoint Imunológico
3.
J Exp Med ; 183(3): 821-7, 1996 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8642286

RESUMO

A rat model of inflammation was used to investigate the biological effects of thrombin. The thrombin-specific inhibitor Hirulog markedly attentuated the carrageenin-induced edema of the paw of the rat. Injection of thrombin into the paw also produced edema. The effect of thrombin was due to activation of its receptor; a thrombin receptor activating peptide (TRAP) reproduced the effects of thrombin in causing edema. TRAP also increased vascular permeability as demonstrated by extravasation of Evans blue and 125I-labeled serum albumin. The release of bioactive amines played an important role in mediating the TRAP-induced edema; the serotonin/histamine antagonist cryproheptadine and the histamine H2 receptor antagonist cimetidine reduced significantly the edema caused by TRAP. Treatment of rats with the mast cell degranulator 48/80 to deplete these cells of their stores of histamine and serotonin abolished completely the ability of TRAP to produce edema. Histochemical examination confirmed that TRAP treatment led to mast cell degranulation. Thus, it has been possible to demonstrate that thrombin acts as an inflammatory mediator in vivo by activating its receptor, which in turn leads to release of vasoactive amines from mast cells.


Assuntos
Antitrombinas/farmacologia , Hirudinas/análogos & derivados , Inflamação/fisiopatologia , Mastócitos/fisiologia , Fragmentos de Peptídeos/farmacologia , Receptores de Trombina/fisiologia , Trombina/farmacologia , Sequência de Aminoácidos , Animais , Carragenina , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/ultraestrutura , Edema , Hirudinas/farmacologia , Histamina/metabolismo , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/patologia , Dados de Sequência Molecular , Ratos , Ratos Wistar , Receptores de Trombina/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Serotonina/metabolismo
4.
Mucosal Immunol ; 11(3): 932-946, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29346349

RESUMO

Integrin α4ß7 mediates the trafficking of leukocytes, including CD4+ T cells, to lymphoid tissues in the gut. Virus mediated damage to the gut is implicated in HIV and SIV mediated chronic immune activation and leads to irreversible damage to the immune system. We employed an immuno-PET/CT imaging technique to evaluate the impact of an anti-integrin α4ß7 mAb alone or in combination with ART, on the distribution of both SIV infected cells and CD4+ cells in rhesus macaques infected with SIV. We determined that α4ß7 mAb reduced viral antigen in an array of tissues of the lung, spleen, axillary, and inguinal lymph nodes. These sites are not directly linked to α4ß7 mediated homing; however, the most pronounced reduction in viral load was observed in the colon. Despite this reduction, α4ß7 mAb treatment did not prevent an apparent depletion of CD4+ T cells in gut in the acute phase of infection that is characteristic of HIV/SIV infection. However, α4ß7 mAb appeared to facilitate the preservation or restoration of CD4+ T cells in gut tissues at later stages of infection. Since damage to the gut is believed to play a central role in HIV pathogenesis, these results support further evaluation of α4ß7 antagonists in the study and treatment of HIV disease.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Colo/virologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Anticorpos Monoclonais/metabolismo , Proteínas da Membrana Bacteriana Externa , Linfócitos T CD4-Positivos/virologia , Sobrevivência Celular , Deleção Clonal , Modelos Animais de Doenças , Humanos , Integrinas/imunologia , Macaca , Receptores de Superfície Celular , Carga Viral
5.
J Clin Invest ; 99(10): 2446-51, 1997 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9153288

RESUMO

Coagulation proteases were tested in a rat model of acute inflammation. Subplantar injection of Factor Xa (10-30 microg) produced a time- and dose-dependent edema in the rat paw, and potentiated carrageenin-induced edema. In contrast, the homologous protease Factor IXa was ineffective. This inflammatory response was recapitulated by the Factor Xa sequence L83FTRKL88(G), which mediates ligand binding to effector cell protease receptor-1 (EPR-1), while a control scrambled peptide did not induce edema in vivo. Conversely, injection of the EPR-1-derived peptide S123PGKPGNQNSKNEPP137 (corresponding to the receptor binding site for Factor Xa) inhibited carrageenin-induced rat paw edema, while the adjacent EPR-1 sequence P136PKKRERERSSHCYP150 was without effect. EPR-1-Factor Xa-induced inflammation was characterized by fast onset and prominent perivascular accumulation of activated and degranulated mast cells, was inhibited by the histamine/serotonin antagonists cyproheptadine and methysergide, but was unaffected by the thrombin-specific inhibitor, Hirulog. These findings suggest that through its interaction with EPR-1, Factor Xa may function as a mediator of acute inflammation in vivo. This pathway may amplify both coagulation and inflammatory cascades, thus contributing to the pathogenesis of tissue injury in vivo.


Assuntos
Coagulação Sanguínea , Fator Xa/fisiologia , Inflamação/fisiopatologia , Sequência de Aminoácidos , Análise de Variância , Animais , Antitrombinas/farmacologia , Carragenina , Ciproeptadina/farmacologia , Edema/induzido quimicamente , Edema/fisiopatologia , Fator Xa/química , Fator Xa/toxicidade , Hirudinas/análogos & derivados , Hirudinas/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Inflamação/induzido quimicamente , Inflamação/patologia , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/patologia , Mastócitos/fisiologia , Metisergida/farmacologia , Dados de Sequência Molecular , Fragmentos de Peptídeos/farmacologia , Fragmentos de Peptídeos/toxicidade , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Antagonistas da Serotonina/farmacologia , Fatores de Tempo
6.
Mol Cell Biol ; 12(8): 3514-21, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1630459

RESUMO

The growth arrest-specific gas5 gene was isolated from mouse genomic DNA and structurally characterized. The transcriptional unit is divided into 12 exons that span around 7 kb. An alternative splicing mechanism gives rise to two mature mRNAs which contain either 11 or 12 exons, and both are found in the cytoplasm of growth-arrested cells. In vivo, the gas5 gene is ubiquitously expressed in mouse tissues during development and adult life. In Friend leukemia and NIH 3T3 cells, the levels of gas5 gene mRNA were high in saturation density-arrested cells and almost undetectable in actively growing cells. Run-on experiments indicated that the gas5 gene is transcribed at the same level in both growing and arrested cells. On the other hand, in dimethyl sulfoxide-induced differentiating cells a sharp decrease in the rate of transcription was observed shortly before the cells reached the postmitotic stage. These results indicate that in density-arrested cells accumulation of gas5 mRNA is controlled at the posttranscriptional level while in differentiating cells expression is regulated transcriptionally.


Assuntos
DNA/genética , Desenvolvimento Embrionário e Fetal , Genes , Células 3T3 , Sequência de Aminoácidos , Animais , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Clonagem Molecular , DNA/isolamento & purificação , Embrião de Mamíferos/fisiologia , Éxons , Feto/fisiologia , Expressão Gênica , Regulação da Expressão Gênica , Leucemia Experimental , Camundongos , Dados de Sequência Molecular , Biossíntese de Proteínas , RNA Mensageiro/genética , Transcrição Gênica , Transfecção
7.
Trends Pharmacol Sci ; 21(5): 170-2, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10785649

RESUMO

Following an injury, the body recruits a mechanism to delimit and repair tissue damage; this phenomenon is known as inflammation. Among the several different pathways that are activated during this process, which is necessary for survival, activation of the coagulation pathway is a key feature. In fact, clinical changes in blood fluidity have been closely related to ongoing inflammation. Recent evidence suggests that serine protease receptors might play a major role in the host defence mechanism at the interface between coagulation and inflammation.


Assuntos
Coagulação Sanguínea/fisiologia , Inflamação/patologia , Receptores de Trombina/metabolismo , Serina Endopeptidases/metabolismo , Animais , Humanos , Receptor PAR-1 , Receptor PAR-2 , Receptores de Trombina/genética , Serina Endopeptidases/química
8.
Br J Pharmacol ; 131(1): 13-6, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960063

RESUMO

Histamine, vascular endothelial growth factor, acetylcholine, oestrogen as well as fluid shear stress activates a mechanism that recruits heat shock protein 90 to the endothelial nitric oxide synthase. The interaction between Hsp90 and eNOS enhances the activation of the enzyme in cells and in intact blood vessels leading to NO production. Intraplantar administration of carrageenan (50 microl paw(-1)) to mice causes an oedema lasting 72 h. Geldanamycin (0.1, 0.3, 1 mg kg(-1)), a specific inhibitor of Hsp-90, that inhibits endothelium-dependent relaxations of the rat aorta, mesentery and middle artery inhibits carrageenan-induced mouse paw oedema in a dose dependent manner. Co-administration to mice of dexamethasone (1 mg kg(-1)) with geldanamycin (0.3 mg kg(-1)) at anti-inflammatory dose causes a loss of the total anti-inflammatory effect of each agent alone. RU 486 (10 mg kg(-1)), a well known glucocorticoid receptorial antagonist, does not inhibit oedema formation but prevents the anti-inflammatory action of dexamethasone (1 mg kg(-1)). Similarly, RU 486 prevents the anti-inflammatory action of geldanamycin (0.3 mg kg(-1)). In conclusion we have described for the first time that geldanamycin, an inhibitor of Hsp90 dependent signal transduction, is anti-inflammatory in vivo implying that Hsp90 is critical for pathways involved in carrageenan-induced paw oedema. In addition the ability of GA to block NO release and reduce oedema formation suggests a therapeutic rationale for specific inhibitors of Hsp90 as potential anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Quinonas/farmacologia , Receptores de Glucocorticoides/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Benzoquinonas , Dexametasona/farmacologia , Edema/prevenção & controle , Proteínas de Choque Térmico HSP90/fisiologia , Lactamas Macrocíclicas , Masculino , Camundongos , Mifepristona/farmacologia
9.
Br J Pharmacol ; 108(3): 573-4, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8467352

RESUMO

An acetylated polypeptide corresponding to residues 2-26 of human lipocortin 1 was synthesized and the anti-inflammatory activity assessed in three models of acute inflammation in rat and mouse. In the carrageenin rat paw oedema test, the peptide produced a maximal inhibition of approximately 41% at the 3 h time point with a 10 micrograms dose. When rat paw oedema was induced by the injection of venom phospholipase A2, the peptide produced a significant inhibition (31%) at the top dose of 20 micrograms per paw. In the mouse air-pouch model, systemic treatment with the peptide produced a dramatic reduction in cytokine-induced leukocyte migration with an ID50 of approximately 40 micrograms per mouse. The N-terminal peptide 2-26 shares the actions of lipocortin 1 in these acute models of inflammation.


Assuntos
Anexina A1/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Peptídeos/farmacologia , Fosfolipases/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Carragenina , Edema/induzido quimicamente , Edema/prevenção & controle , Interleucina-1/farmacologia , Masculino , Camundongos , Dados de Sequência Molecular , Neutrófilos/efeitos dos fármacos , Fosfolipases A , Fosfolipases A2 , Ratos , Ratos Wistar
10.
Br J Pharmacol ; 126(2): 478-84, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10077241

RESUMO

1. Several thrombin cellular effects are dependent upon stimulation of proteinase activated receptor-1 (PAR-1) localized over the cellular surface. Following activation by thrombin, a new N-terminus peptide is unmasked on PAR-1 receptor, which functions as a tethered ligand for the receptor itself. Synthetic peptides called thrombin receptor activating peptides (TRAPs), corresponding to the N-terminus residue unmasked, reproduce several thrombin cellular effects, but are devoid of catalytic activity. We have evaluated the bronchial response to intravenous administration of human alpha-thrombin or a thrombin receptor activating peptide (TRAP-9) in anaesthetized, artificially ventilated guinea-pigs. 2. Intravenous injection of thrombin (100 microkg(-1)) caused bronchoconstriction that was recapitulated by injection of TRAP-9 (1 mg kg(-1)). Animal pretreatment with the thrombin inhibitor Hirulog (10 mg kg(-1) i.v.) prevented thrombin-induced bronchoconstriction, but did not affect bronchoconstriction induced by TRAP-9. Both agents did not induce bronchoconstriction when injected intravenously to rats. 3. The bronchoconstrictor effect of thrombin and TRAP-9 was subjected to tolerance; however, in animals desensitized to thrombin effect, TRAP-9 was still capable of inducing bronchoconstriction, but not vice versa. 4. Depleting animals of circulating platelets prevented bronchoconstriction induced by both thrombin and TRAP-9. 5. Bronchoconstriction was paralleled by a biphasic change in arterial blood pressure, characterized by a hypotensive phase followed by a hypertensive phase. Thrombin-induced hypotension was not subject to tolerance and was inhibited by Hirulog; conversely, hypertension was subject to tolerance and was not inhibited by Hirulog. Hypotension and hypertension induced by TRAP-9 were neither subject to tolerance nor inhibited by Hirulog. 6. Our results indicate that thrombin causes bronchoconstriction in guinea-pigs through a mechanism that requires proteolytic activation of its receptor and the exposure of the tethered ligand peptide. Platelet activation might be triggered by the thrombin effect.


Assuntos
Broncoconstrição/efeitos dos fármacos , Broncoconstritores/farmacologia , Fragmentos de Peptídeos/farmacologia , Trombina/farmacologia , Animais , Plaquetas/citologia , Plaquetas/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Líquido da Lavagem Broncoalveolar/citologia , Broncoconstrição/fisiologia , Cobaias , Contagem de Leucócitos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Contagem de Plaquetas , Receptores de Trombina/química
11.
Br J Pharmacol ; 132(6): 1229-34, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11250873

RESUMO

1. Protease activated receptor-2 (PAR2) is a seven transmembrane domain G protein coupled receptor proteolytically activated. PAR2, together with other PARs, can be also activated by peptides mimicking the sequence of the receptor tethered ligand. We have evaluated the effect of systemic administration of a peptide activating PAR2 (PAR2-AP, SLIGRL) on histamine-induced increase in lung resistances in the guinea-pig. 2. Intravenous administration of PAR2-AP (1 mg kg(-1)) significantly inhibited histamine-induced increase in lung resistance in a time-dependent fashion that was not abolished by indomethacin or vagotomy. 3. Bronchoprotective effect of PAR2-AP was not reversed by the cyclo-oxygenase inhibitor, indomethacin, the nitric oxide synthetase inhibitor, L-NAME, nor by the non-selective beta-antagonist, propranolol. 4. Indomethacin augmented the bronchoconstriction to histamine which was inhibited by PAR2-AP. Furthermore, in vagotomized animals, the bronchial hyper-responsiveness to histamine was significantly reduced, and in these circumstances, PAR2-AP still retained the capacity to provide bronchoprotection against histamine. 5. PAR2-AP also produced a modest reduction in histamine-induced protein leakage in trachea and upper bronchi. 6. Our results indicated that PAR2 might have a bronchoprotective role in the guinea-pig in vivo independent of prostaglandin or nitric oxide release.


Assuntos
Broncoconstrição/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Substâncias Protetoras/farmacologia , Receptores de Trombina/metabolismo , Análise de Variância , Animais , Espasmo Brônquico/induzido quimicamente , Espasmo Brônquico/prevenção & controle , Modelos Animais de Doenças , Cobaias , Histamina , Fragmentos de Peptídeos/uso terapêutico , Permeabilidade , Substâncias Protetoras/uso terapêutico , Receptor PAR-2 , Vagotomia
12.
Br J Pharmacol ; 130(6): 1399-405, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10903982

RESUMO

1. Anti-inflammatory non steroidal drugs releasing NO (NO-NSAIDs) are a new class of anti-inflammatory drugs to which has been added an NO-releasing moiety. These compounds have been shown to retain the anti-inflammatory, analgesic and antipyretic activity of the parent compound but to be devoid of gastrointestinal (GI) toxicity. 2. Freund's adjuvant (FA) arthritis was induced in rats by a single intraplantar injection into the right hindpaw of 100 microl of mycobacterium butirricum (6 mg ml(-1)). The effect of equimolar doses of naproxen (1, 3 and 10 mg kg(-1)) and NO-naproxen (1.5, 4.5 and 16 mg kg(-1)) was evaluated using two dosage regimen protocols: (i) preventive, starting oral administration of the drugs at the time of induction of arthritis and for the following 21 days (day 1 - 21); (ii) therapeutic, starting oral administration of the drugs 7 days after adjuvant injection and for the following 14 days (day 7 - 21). 3. Hindpaw swelling (days 3, 7, 11, 14, 17, 21) and nociception (days 15 and 21) were measured. On day 22 rats were sacrificed, draining lymph nodes were removed and T cells isolated. In vitro proliferation of T cells following stimulation with concanavalin A (0.5 - 5 microg ml(-1)) was measured using a tritiated thymidine incorporation assay. IL-2 receptor expression on T cells was measured by FACS analysis. 4. Naproxen and NO-naproxen showed similar activity in reducing oedema formation in the non-injected (controlateral) hindpaw. Both drugs showed anti-nociceptive effect. NO-naproxen was anti-nociceptive at a dose of 4.5 mg kg(-1) while naproxen showed the same extent of inhibition only at a dose of 10 mg kg(-1). 5. T cells were isolated and characterized by FACS analysis. Stimulation of isolated T cells with concanavallin A in vitro caused a significant increase in thymidine uptake. NO-naproxen at a dose of 4.5 mg kg(-1) inhibited T cell proliferation to the same extent as 10 mg kg(-1) of naproxen. 6. Inhibition of T cell proliferation was well correlated with reduced IL-2 receptor expression on T cells. In addition, NO-naproxen reduced both IL-1beta and TNFalpha plasma levels whilst naproxen reduced IL-1beta levels only. 7. In conclusion, both naproxen and NO-naproxen reduce inflammation and nociception associated with arthritis. In addition NO-naproxen interferes to a larger extent with cellular mechanism involved in T cell activation in rat adjuvant arthritis indicating that introduction of the NO moiety in the naproxen structure increases the effect at the level of the immune system.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Artrite Experimental/prevenção & controle , Inflamação/prevenção & controle , Naproxeno/análogos & derivados , Óxido Nítrico/farmacologia , Nociceptores/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Animais , Artrite Experimental/imunologia , Artrite Experimental/fisiopatologia , Relação Dose-Resposta a Droga , Edema/prevenção & controle , Citometria de Fluxo , Membro Posterior , Interleucina-1/sangue , Masculino , Naproxeno/farmacologia , Dor/prevenção & controle , Medição da Dor , Ratos , Ratos Endogâmicos Lew , Receptores de Interleucina-2/efeitos dos fármacos , Receptores de Interleucina-2/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timidina/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
13.
Eur J Pharmacol ; 264(2): 183-90, 1994 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-7851481

RESUMO

111Indium-labelled platelets were continuously monitored in the cranial vasculature of anaesthetised rabbits and thrombin inhibitors and anti-coagulants were tested on the sustained platelet accumulation induced by intracarotid injection of thrombin (90 U/kg). Pretreatment, commencing 30 min prior to thrombin, with a 1-h intracarotid infusion of D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK; 0.25-1.0 micrograms/kg per min), unfractionated heparin (Multiparin; 5-20 U/kg bolus + 0.75-3.0 U/kg per min infusion) or low molecular weight heparin (Fragmin; 2.4-9.6 U/kg per min) produced dose-related reductions in platelet accumulation. Continuous infusion of acetyl-D-phenylalanyl-prolyl-boroarginine (DuP-714 ester; 30 micrograms/kg per min) for 30 min induced marked accumulation of platelets in the pulmonary circulation in the absence of thrombin. Bolus intracarotid injection, 1 min before thrombin, of Hirulog (0.05-0.2 mg/kg), PPACK (10-30 micrograms/kg), Multiparin (25-100 U/kg), Fragmin (150 U/kg) or DuP-714 ester (15-30 micrograms/kg) caused significant reductions in platelet accumulation. When injected 1 min after thrombin, Hirulog (1 mg/kg), PPACK (100 micrograms/kg), Fragmin (150 U/kg) and DuP-714 ester (30 micrograms/kg) had no significant effect and Multiparin (100 U/kg) increased platelet accumulation. The results demonstrate that pretreatment with a range of thrombin inactivators, acting via different mechanisms, can inhibit thrombin-induced cerebral thromboembolism in the rabbit.


Assuntos
Anticoagulantes/uso terapêutico , Antitrombinas/uso terapêutico , Embolia e Trombose Intracraniana/prevenção & controle , Trombina/antagonistas & inibidores , Clorometilcetonas de Aminoácidos/administração & dosagem , Clorometilcetonas de Aminoácidos/farmacologia , Clorometilcetonas de Aminoácidos/uso terapêutico , Animais , Anticoagulantes/administração & dosagem , Anticoagulantes/farmacologia , Antitrombinas/administração & dosagem , Antitrombinas/farmacologia , Plaquetas/efeitos dos fármacos , Compostos de Boro/administração & dosagem , Compostos de Boro/farmacologia , Compostos de Boro/uso terapêutico , Dalteparina/administração & dosagem , Dalteparina/farmacologia , Dalteparina/uso terapêutico , Relação Dose-Resposta a Droga , Fibrinolíticos/administração & dosagem , Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Heparina/administração & dosagem , Heparina/farmacologia , Heparina/uso terapêutico , Terapia com Hirudina , Hirudinas/administração & dosagem , Hirudinas/análogos & derivados , Hirudinas/farmacologia , Índio , Infusões Intra-Arteriais , Embolia e Trombose Intracraniana/induzido quimicamente , Marcação por Isótopo , Masculino , Peso Molecular , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Fragmentos de Peptídeos/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/uso terapêutico , Circulação Pulmonar/efeitos dos fármacos , Coelhos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Relação Estrutura-Atividade , Trombina/administração & dosagem , Trombina/toxicidade
14.
Eur J Pharmacol ; 257(3): 249-55, 1994 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-8088345

RESUMO

In this study, we assessed the effects of addition of a nitroxybutyl moiety to diclofenac on its ulcerogenic properties. The diclofenac derivative, 'nitrofenac', was examined in terms of its ability to induce acute gastric erosions and chronic-type gastric ulcers in rats and rabbits, respectively. The effects of these compounds on prostaglandin synthesis in the stomach and at a site of peripheral inflammation were also assessed, as were their anti-inflammatory properties in a model of acute inflammation. Diclofenac dose-dependently caused acute gastric mucosal injury in the rat at all doses tested (10-40 mg/kg), that was significantly greater in severity than that observed with the same doses of nitrofenac. In rabbits, twice-daily administration of diclofenac induced penetrating antral ulcers and small intestinal damage. No damage was observed in the stomach or small intestine of rabbits receiving nitrofenac. Diclofenac and nitrofenac exerted similar inhibitory effects on prostaglandin E2 synthesis in the stomach and in a carrageenan-sponge model of peripheral inflammation. These compounds exerted similar inhibitory effects on carrageenan-induced paw edema. Nitrofenac, but not diclofenac, caused a significant increase in plasma levels of nitrate/nitrite. These results suggest that the addition of a nitroxybutyl moiety to diclofenac markedly reduces the ulcerogenic properties of this compound without interfering with its ability to inhibit cyclo-oxygenase activity or to reduce acute inflammation.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Diclofenaco/análogos & derivados , Mucosa Gástrica/efeitos dos fármacos , Úlcera Gástrica/induzido quimicamente , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Diclofenaco/química , Diclofenaco/farmacologia , Diclofenaco/toxicidade , Mucosa Gástrica/irrigação sanguínea , Mucosa Gástrica/metabolismo , Inflamação/tratamento farmacológico , Masculino , Nitratos/sangue , Nitritos/sangue , Prostaglandinas/biossíntese , Coelhos , Ratos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Estômago/irrigação sanguínea , Estômago/efeitos dos fármacos
15.
Eur J Pharmacol ; 252(2): 147-54, 1994 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-8157055

RESUMO

Platelets contain a phospholipase A2 in their granules which can be released in response to various activating stimuli in vitro as well as in vivo. Human recombinant phospholipase A2 (1-10 micrograms/ml) had no direct effect on platelet aggregation in vitro using rabbit platelet rich plasma. In contrast human recombinant phospholipase A2 (1-20 micrograms/ml) was able to inhibit aggregation of washed rabbit platelet in vitro induced by collagen (0.250-2.0 micrograms/ml). When rabbit platelet rich plasma was recalcified with CaCl2 1 M in the presence of the thrombin inhibitor hirulog (10 micrograms/ml), human recombinant phospholipase A2 (10-40 micrograms/ml) was able to inhibit platelet aggregation. The anti-aggregatory effect was removed by incubation of platelet rich plasma with a monoclonal anti-human recombinant phospholipase A2 antibody. Human recombinant phospholipase A2 (1-10 micrograms) inhibited 111In-labelled platelet accumulation within the thoracic region of rats and guinea pigs induced by i.v. administration of submaximal doses of collagen or adenosine diphosphate. Phospholipase A2 (1-20 micrograms/ml) from Naja mocambique mocambique snake venom had no direct effect on platelet aggregation in vitro. However, Naja phospholipase A2 administered i.v. to rats or guinea pigs was able to induce a dose related accumulation of 111In-labelled platelet within the thoracic region. The inhibitory effect of exogenously added human recombinant phospholipase A2 on platelet aggregation in vivo suggests a possible pathophysiological role for the extracellular form of phospholipase A2 but this property is not a feature of all phospholipase A2 preparations.


Assuntos
Fosfolipases A/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , 6-Cetoprostaglandina F1 alfa/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Cobaias , Humanos , Técnicas In Vitro , Radioisótopos de Índio , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Fosfolipases A/imunologia , Fosfolipases A2 , Coelhos , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Tromboxano B2/metabolismo
16.
Thromb Res ; 70(4): 337-42, 1993 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-8332963

RESUMO

Extracellular phospholipase A2 is secreted from the platelets upon activation by a stimulus such as thrombin. The secreted enzyme has been recently cloned and the recombinant protein produced. Snake venom PLA2 effect on platelet and coagulation has been extensively studied (for review see 3,4) and it has been proposed that the anticoagulant phospholipases may inhibit coagulation by competing with clotting proteins for the lipid surface. Structure function relationship for PLA2s with anticoagulant activity indicates that the activity is conferred by positively charged aminoacids between residues 54 and 77. The corresponding segment of human recombinant secreted platelet PLA2 (r-hnps-PLA2) possesses five positively charged aminoacids in this region being at the identical positions to those of PLA2s with known anticoagulant activities. Here using human and rat plasma we have demonstrated for the first time that the recombinant human extracellular secreted platelet PLA2 increases activated partial thromboplastin time but not prothrombin time.


Assuntos
Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Fosfolipases A/farmacologia , Animais , Plaquetas/metabolismo , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Masculino , Tempo de Tromboplastina Parcial , Fosfolipases A/metabolismo , Fosfolipases A2 , Plasma/efeitos dos fármacos , Tempo de Protrombina , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia
17.
Thromb Res ; 83(6): 405-19, 1996 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-8885136

RESUMO

We studied the effects of i.v. administration of endotoxin (Escherichia coli, Serotype 0127:B8) on the kinetics of 111In-labelled platelets within the pulmonary, abdominal and splenic vascular beds of the rat, and on the radioactivity present in dissected samples of splenic and hepatic tissues. Bolus i.v. injection of endotoxin to anaesthetised rats caused a dose-dependent, transient accumulation of 111In-labelled platelets in the pulmonary vasculature. Increased radioactivity, suggestive of platelet sequestration, was detected in tissue samples from both the spleen and the liver at 4.5 h compared to the radioactivity detected in those organs in vehicle treated rats. The modulation of endotoxin-induced platelet accumulation within the lungs, spleen and liver by pharmacological agents was investigated. The pulmonary, hepatic and splenic platelet accumulation induced by endotoxin was unaffected by pre-treatment of the animals with indomethacin, Hirulog or L-NAME. Pre-treatment with dexamethasone significantly reduced the platelet accumulation within the liver and spleen, but not the lungs.


Assuntos
Plaquetas/efeitos dos fármacos , Endotoxinas/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Hirudinas/análogos & derivados , Hirudinas/farmacologia , Indometacina/farmacologia , Fígado/citologia , Fígado/efeitos dos fármacos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Baço/citologia , Baço/efeitos dos fármacos
18.
Thromb Res ; 79(1): 73-81, 1995 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-7495106

RESUMO

We have recently shown that the introduction of a nitroxybutylester moiety into flurbiprofen, to form Flurbi-NO, results in a compound with markedly reduced undesired effects in the gastrointestinal tract. This effect has been shown to be linked to nitric oxide release from the Flurbi-NO. Here we have investigated whether this is associated with a reduction in platelet aggregability in vivo, as assessed in a mouse model of thromboembolism and a rat model of platelet aggregation, and found in both models that Flurbi-NO is more potent than flurbiprofen at inhibiting collagen-induced platelet aggregation. Further in vitro studies using human washed platelets and cells in culture suggest that this is due to the release of NO from Flurbi-NO following the action of (possibly plasma) esterases. Together with our earlier data, these results strongly suggest that Flurbi-NO and other members of this class of drugs, have particular potential as anti-thrombotic agents devoid of gastrointestinal side effects.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Fibrinolíticos/uso terapêutico , Flurbiprofeno/análogos & derivados , Inibidores da Agregação Plaquetária/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Tromboembolia/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Colágeno/toxicidade , Avaliação Pré-Clínica de Medicamentos , Epinefrina/toxicidade , Fibrinolíticos/farmacologia , Flurbiprofeno/farmacologia , Flurbiprofeno/uso terapêutico , Humanos , Masculino , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Inibidores da Agregação Plaquetária/farmacologia , Ratos , Ratos Wistar , Tromboembolia/induzido quimicamente
19.
Phytochemistry ; 57(4): 565-9, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11394858

RESUMO

A phytochemical investigation of the extracts obtained from bulbs of leek. Allium porrum L. has led to the isolation of five flavonoid glycosides based on the kaempferol aglycone. Two of them are new compounds and have been identified as kaempferol 3-O-[2-O-(trans-3-methoxy-4-hydroxycinnamoyl)-beta-D-galactopyranosyl]-(1-->4)-O-beta-D-glucopyranoside, and kaempferol 3-O-[2-O-(trans-3-methoxy-4-hydroxycinnamoyl)-beta-D-glucopyranosyl]-(1-->6)-O-beta-D-glucopyranoside, on the basis of spectroscopic methods, including 2D NMR. The isolated compounds have been evaluated for their human platelet anti-aggregation activity.


Assuntos
Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Quempferóis , Cebolas/química , Agregação Plaquetária/efeitos dos fármacos , Quercetina/isolamento & purificação , Flavonoides/química , Humanos , Espectroscopia de Ressonância Magnética , Quercetina/análogos & derivados , Quercetina/química , Quercetina/farmacologia
20.
Phytochemistry ; 41(2): 531-6, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8821433

RESUMO

From wild garlic Allium ursinum three new flavonoid glycosides were identified as kaempferol 3-O-beta-neohesperidoside-7-O-[2-O-(trans-p-coumaroyl)]-beta -D- glucopyranoside, kaempferol 3-O-beta-neohesperidoside-7-O-[2-O-(trans-feruloyl)]-beta-D- glucopyranoside, kaempferol 3-O-beta-neohesperidoside-7-O-[2-O-(trans-p-coumaroyl)-3-O-b eta-D- glucopyranosyl]-beta-D-glucopyranoside and characterized as the peracetates. Additionally, two known flavonoid glycosides kaempferol 3-O-beta-glucopyranoside and kaempferol 3-O-beta-neohesperidoside were isolated. The isolated compounds showed an inhibition of human platelet aggregation.


Assuntos
Flavonoides/química , Flavonoides/farmacologia , Alho/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia , Plaquetas/efeitos dos fármacos , Sequência de Carboidratos , Flavonoides/isolamento & purificação , Glicosídeos/química , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Extratos Vegetais/isolamento & purificação , Inibidores da Agregação Plaquetária/isolamento & purificação , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Ultravioleta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA