Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Thromb Res ; 135(2): 255-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25550188

RESUMO

BACKGROUND AND AIMS: Evidence associates polyphenol-rich foods to reduction of low-grade inflammation and mortality for cardiovascular disease, the mechanisms underlying such effects being still unclear. Consumption of a fatty meal by healthy volunteers induces rapid and reversible low-grade inflammation. The aim of the present study was to evaluate the effect of orange juice on cellular modifications induced by a fatty meal. METHODS AND RESULTS: 18 apparently healthy subjects consumed a fatty meal, during which they drunk orange juice, either blond or red, or water, according to a randomized cross-over design. Two hours after the end of the fatty meal, both white blood cell (WBC) and platelet counts significantly increased (12.5 and 5%, respectively), while mean platelet volume decreased and a 25% release of myeloperoxidase (MPO) from polymorphonuclear leukocyte occurred. Both juices significantly prevented WBC increase and MPO degranulation, in respect to control. Triglycerides significantly increased (42%) after the fatty meal, but at a lower extent when red orange juice was consumed with the meal (20%), in respect to blond orange juice or control. This effect was statistically significant in the subgroup of 8 subjects with hypertriglyceridemia. Vascular stiffness (augmentation index), measured by Endo-PAT2000, significantly decreased after the meal only in conjunction with red orange juice. CONCLUSION: In healthy subjects the concomitant intake of orange juice may prevent the low-grade inflammatory reaction induced by a fatty meal, at cellular and possibly at vascular function levels. The relative role of different polyphenols on the observed effects of orange juices remains to be established.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Citrus sinensis/metabolismo , Inflamação/dietoterapia , Triglicerídeos/metabolismo , Adulto , Bebidas , Feminino , Voluntários Saudáveis , Humanos , Masculino , Refeições , Peroxidase , Período Pós-Prandial , Fatores de Risco
2.
Nutr Metab Cardiovasc Dis ; 21(1): 46-53, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19819677

RESUMO

BACKGROUND AND AIMS: Several studies have shown that moderate alcohol consumption reduces the risk of coronary heart disease, a disease related to oxidative stress. However, the effects of different alcoholic beverages on antioxidant status are not fully known. Our aim was therefore to compare the effects of a moderate intake of an alcoholic beverage with high polyphenol content (red wine) and another without polyphenol content (gin) on plasma antioxidant vitamins, lipid profile and oxidability of low-density lipoprotein (LDL) particles. METHODS AND RESULTS: Forty healthy men (mean age, 38 years) were included in a randomised cross-over trial. After a 15-day washout period, subjects received 30 g/ethanol/d as either wine or gin for 28 days. Diet and exercise were monitored. Before and after each intervention, we measured serum vitamins, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase activities, lipid profile, oxidized LDL and LDL resistance to ex-vivo oxidative stress. Compared to gin intervention, wine intake reduced plasma SOD activity [-8.1 U/gHb (95% confidence interval, CI, -138 to -25; P=0.009)] and MDA levels [-11.9 nmol/L (CI, -21.4 to-2.5; P=0.020)]. Lag phase time of LDL oxidation analysis also increased 11.0 min (CI, 1.2-20.8; P=0.032) after wine, compared to gin, whereas no differences were observed between the two interventions in oxidation rate of LDL particles. Peroxide concentration in LDL particles also decreased after wine [-0.18 nmol/mL (CI, -0.3 to-0.08;P=0.020)], as did plasma oxidized LDL concentrations [-11.0 U/L (CI,-17.3 to -6.1; P=0.009)]. CONCLUSION: Compared to gin, red wine intake has greater antioxidant effects, probably due to its high polyphenolic content.


Assuntos
Bebidas Alcoólicas , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Superóxido Dismutase/sangue , Vinho , Adulto , Antioxidantes/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Estudos Cross-Over , Dieta , Exercício Físico/fisiologia , Comportamento Alimentar , Flavonoides/farmacologia , Humanos , Lipídeos/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Fenóis/farmacologia , Polifenóis , Estudos Prospectivos , Vitaminas/sangue
3.
J Thromb Haemost ; 3(2): 346-50, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15670042

RESUMO

The concept of the 'French paradox' has been recently challenged. As it is difficult in a short period to produce direct clinical evidence of the protective effect of red wine on thrombosis, we evaluated such a possibility in an experimental model mimicking the conditions of the 'French paradox'. Normolipidemic rats (FNL) were fed a standard diet or a 2% cholesterol-rich-diet (Ch-rich-diet) for 5 months: the latter was given either alone (FNL + D) or in combination with 'alcohol-free' red wine (FNL + D + 5 W). Arterial thrombosis was measured as the occlusion time (OT) of an artificial prosthesis inserted into the abdominal aorta. Lipid levels, platelet adhesion to fibrillar collagen, factor VII (FVII) clotting activity and fibrinogen levels were also measured. Compared to animals fed a standard diet, Ch-rich diet induced in FNL rats a several-fold increase in lipids and FVII levels with a concomitant significant increase in both thrombotic tendency (shortening of the OT) and platelet adhesion. 'Alcohol-free' red wine supplementation almost completely reverted the prothrombotic effect of the Ch-rich-diet. Indeed, the OT was prolonged from 78 +/- 3 to 122 +/- 10 h (P < 0.01), while platelet adhesion to fibrillar collagen was reduced from 49 +/- 3.5% to 30 +/- 2.8%. Neither the increase in lipid levels induced by Ch-rich diet nor FVII or fibrinogen levels were modified by wine supplementation. In conclusion, in experimental animals, this study supports the concept of the 'French paradox' that regular consumption of wine (rather than alcohol) was able to prevent arterial thrombosis associated with dietary-induced hypercholesterolemia, an effect mediated by downregulation of platelet function.


Assuntos
Hipercolesterolemia/complicações , Trombose/prevenção & controle , Vinho , Animais , Colesterol/administração & dosagem , Dieta , Modelos Animais de Doenças , Etanol/análise , Hipercolesterolemia/sangue , Lipídeos/sangue , Masculino , Adesividade Plaquetária , Ratos , Ratos Sprague-Dawley
5.
Br J Cancer ; 89(4): 763-73, 2003 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-12915891

RESUMO

The cytotoxic effect of Aplidin was investigated on fresh leukaemia cells derived from children with B-cell-precursor (BCP) acute lymphoblastic leukaemia (ALL) by using stromal-layer culture system and on four cell lines, ALL-PO, Reh, ALL/MIK and TOM-1, derived from patients with ALL with different molecular genetic abnormalities. In ALL cell lines Aplidin was cytotoxic at nanomolar concentrations. In the ALL cell lines the drug-induced cell death was clearly related to the induction of apoptosis and appeared to be p53-independent. Only in ALL-PO 20 nM Aplidin treatment caused a block of vascular endothelial growth factor (VEGF) secretion and downregulation of VEGF-mRNA, but Aplidin cytotoxicity does not seem to be related to VEGF inhibition since the sensitivity of ALL-PO cells to Aplidin is comparable to that observed for the other cells used. Aplidin induced a G(1) and a G(2) M block in ALL cell lines. In patient-derived leukaemia cells, Aplidin induced a strong cytotoxicity evidenced in a stroma-supported immunocytometric assay. Cells from children with genetic abnormalities such as t(9;22) and t(4;11) translocations, associated with an inferior treatment outcome, were sensitive to Aplidin to the same extent as that observed in other BCP-ALL cases. Aplidin exerted a strong cell killing effect (>88%) against primary culture cells from five relapsed ALL cases, at concentrations much lower than those reported to be achieved in plasma of patients receiving Aplidin at recommended doses. Taken together these data suggest that Aplidin could be a new anticancer drug to be investigated in ALL patients resistant to available therapy.


Assuntos
Antineoplásicos/farmacologia , Depsipeptídeos , Resistencia a Medicamentos Antineoplásicos , Peptídeos Cíclicos/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Adolescente , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Caspase 3 , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Fatores de Crescimento Endotelial/genética , Fatores de Crescimento Endotelial/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Cariotipagem , Linfocinas/genética , Linfocinas/metabolismo , Masculino , Espectrometria de Massas , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , RNA Mensageiro/metabolismo , RNA Neoplásico/metabolismo , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
6.
Eur J Cancer ; 38(18): 2463-75, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12460792

RESUMO

Inositol-containing molecules are involved in important cellular functions, including signalling, membrane transport and secretion. Our interest is in lysophosphatidylinositol and the glycerophosphoinositols, which modulate cell proliferation and G-protein-dependent activities such as adenylyl cyclase and phospholipase A(2). To investigate the role of glycerophosphoinositol (GroPIns) in the modulation of Ras-dependent pathways and its correlation to Ras transformation, we employed a novel liquid chromatography-tandem mass spectrometry technique to directly measure GroPIns in cell extracts. The cellular levels of GroPIns in selected parental and Ras-transformed cells, and in some carcinoma cells, ranged from 44 to 925 microM, with no consistent correlation to Ras transformation across all cell lines. Moreover, the derived cellular inositol concentrations revealed a wide range ( approximately 150 microM to approximately 100 mM) under standard [(3)H]-inositol-loading, suggesting a complex relationship between the inositol pool and the phosphoinositides and their derivatives. We have investigated these pools under specific loading conditions, designing a further HPLC analysis for GroPIns, combined with mass determinations of cellular phosphatidylinositol 4,5-bisphosphate. The data demonstrate that limiting inositol conditions identify a preferred pathway of inositol incorporation and retention into the polyphosphoinositides pool. Thus, under conditions of increased metabolic activity, such as receptor stimulation or cellular transformation, the polyphosphoinositide levels will be maintained at the expense of phosphatidylinositol and the turnover of its aqueous derivatives.


Assuntos
Transformação Celular Neoplásica/genética , Genes ras , Fosfatos de Inositol/fisiologia , Inositol/fisiologia , Lisofosfolipídeos/fisiologia , Cromatografia Líquida/métodos , Humanos , Líquido Intracelular/química , Espectrometria de Massas/métodos , Células Tumorais Cultivadas
7.
Biochem J ; 360(Pt 3): 675-81, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11736659

RESUMO

Peptide methionine sulphoxide reductase (MsrA; EC 1.8.4.6) is a ubiquitous enzyme catalysing the reduction of methionine sulphoxide to methionine in proteins, while the glutathione S-transferases (GSTs) are a major family of detoxification enzymes. A gene homologous to MsrA was identified in a chromosomal fragment from the bacterium Ochrobactrum anthropi, and this gene is located just downstream of a GST gene identified previously (OaGST) [Favaloro, Tamburro, Angelucci, De Luca, Melino, Di Ilio and Rotilio (1998) Biochem. J. 335, 573-579]. This raises the question of whether the products of these two genes may be involved in a common cellular protection function. To test this hypothesis, the hypothetical MsrA protein has been overexpressed in Escherichia coli as a functional 51 kDa GST fusion protein. Following cleavage with thrombin and purification, the soluble 24 kDa protein showed MsrA activity with N-acetylmethionine sulphoxide as substrate, as well as with other sulphoxide compounds. Therefore polyclonal antibodies were raised against the recombinant protein, and the modulation of MsrA in this bacterium, grown in the presence of different stimulants simulating several stress conditions, was investigated. The level of expression of MsrA was detected both by measuring the mRNA level and by immunoblotting experiments, in addition to measuring its catalytic activity. MsrA is a constitutive enzyme which is also inducible by chemical stress involving phenolic compounds such as phenol and 4-chlorophenol. Recently we reported that the GST of this bacterium, like MsrA, is only modulated by toxic chemical compounds [Favaloro, Tamburro, Trofino, Bologna, Rotilio and Heipieper (2000) Biochem. J. 346, 553-559]; therefore this is the first indication of a co-induction of the MsrA and GST enzymes during chemical stress.


Assuntos
Glutationa Transferase/genética , Ochrobactrum anthropi/enzimologia , Oxirredutases/genética , Sequência de Aminoácidos , Northern Blotting , Clonagem Molecular , Indução Enzimática , Glutationa Transferase/biossíntese , Glutationa Transferase/química , Metionina Sulfóxido Redutases , Dados de Sequência Molecular , Ochrobactrum anthropi/fisiologia , Oxirredutases/biossíntese , Oxirredutases/química , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transcrição Gênica
9.
Int J Cancer ; 88(1): 1-6, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10962432

RESUMO

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundant heterocyclic amine formed in meat and fish during cooking and can be used as a model compound for this class of chemicals possibly involved in human carcinogenesis. Knowing the exposure to heterocyclic amines is important for establishing their role in human diseases. Serum albumin (SA) and globin (Gb) adducts were first tested as biomarkers of exposure to PhIP in male Fischer 344 rats given oral doses of 0.1, 0.5, 1 and 10 mg/kg. Blood samples were collected 24 hr after treatment and PhIP released from SA and Gb after acidic hydrolysis was analyzed by gas chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry. PhIP-SA and Gb adducts increased linearly with the dose. Studies on 35 volunteers with different dietary habits exhibited that diet was a major determinant in the formation of both adducts. PhIP-SA adducts were significantly higher in meat consumers than in vegetarians (6.7 +/- 1.6 and 0.7 +/- 0.3 fmol/mg SA; respectively, mean +/- SE; p = 0.04, Mann-Whitney U test). The Gb adduct pattern was quantitatively lower but paralleled SA (3 +/- 0.8 in meat consumers and 0.3 +/- 0.1 in vegetarians). PhIP-SA adducts were no different in smokers and in non-smokers. The results show for the first time that PhIP-blood protein adducts are present in humans not given the synthetic compound. Both biomarkers appear to be suitable for assessing dietary exposure and internal PhIP dose and may be promising tools for studying the role of heterocyclic amines in the etiology of colon cancer and other diseases.


Assuntos
Carcinógenos/metabolismo , Dieta , Hemoglobinas/metabolismo , Imidazóis/sangue , Albumina Sérica/metabolismo , Animais , Biomarcadores/sangue , Cromatografia Líquida , Dieta Vegetariana , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hidrólise , Masculino , Espectrometria de Massas , Carne , Ligação Proteica , Ratos , Ratos Endogâmicos F344 , Sensibilidade e Especificidade
10.
J Agric Food Chem ; 48(4): 1239-42, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10775378

RESUMO

Benzothiazoles are a part of the molecular structure of a large number of natural products, biocides, drugs, food flavors, and industrial chemicals. They also appear in the environment mainly as a result of their production and use as rubber vulcanization accelerators. A new headspace solid-phase microextraction (HS-SPME) method for analysis of benzothiazole (BTH) in wine is described. This method is fast, inexpensive, and does not require solvents. The detection limit of BTH in wine was 45 ppt with linearity up to 100 ppb. The quantification of BTH is performed by the standard additions method and does not require the use of an internal standard. We have analyzed 12 wines from different grape varieties grown in several regions, using SPME extraction and gas chromatography-mass spectrometry (GC-MS) detection. Under these experimental conditions, benzothiazole was found in all wines analyzed. Concentration levels in samples varied from 0.24 microg/L (Vermentino) to 1.09 microg/L (Franciacorta).


Assuntos
Resíduos de Drogas/análise , Tiazóis/análise , Vinho/análise , Benzotiazóis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Itália , Microquímica , Sensibilidade e Especificidade
11.
Biochem J ; 346 Pt 2: 553-9, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10677378

RESUMO

The gluthathione S-transferase gene of the atrazine-degrading bacterium Ochrobactrum anthropi (OaGST) encodes a single-subunit polypeptide of 201 amino acid residues (Favaloro et al. 1998, Biochem. J. 335, 573-579). RNA blot analysis showed that the gene is transcribed into an mRNA of about 800 nucleotides, indicating a monocistronic transcription of the OaGST gene. The modulation of OaGST in this bacterium, in the presence of different stimulants, was investigated. The level of expression of OaGST was detected both by measuring the mRNA level and by immunoblotting experiments. OaGST is a constitutive enzyme which is also inducible by several stimulants. In fact, atrazine caused an increase in the expression of OaGST even at concentrations which had no effect on growth rates of the bacteria. Moreover, the presence of other aromatic substrates of this bacterium, such as phenol and chlorophenols, leads to a marked enhancement in OaGST expression. In this case, the expression of OaGST was related to growth inhibition and membrane damage caused by these hydrophobic compounds, and to the adaptive responses of the cell membranes. On the other hand, toluene and xylene, two aromatic compounds not degradable by this bacterium, did not induce the OaGST expression. The same was observed for other stress conditions such as low pH, heat shock, hydrogen peroxide, osmotic stress, starvation, the presence of aliphatic alcohols or heavy metals. These results suggest a co-regulation of the OaGST gene by the catabolic pathways of phenols and chlorophenols in this bacterium. Therefore, OaGST could function as a detoxifying agent within the catabolism of these xenobiotics.


Assuntos
Glutationa Transferase/metabolismo , Ochrobactrum anthropi/enzimologia , Especificidade por Substrato , Xenobióticos
12.
J Chromatogr B Biomed Sci Appl ; 731(2): 335-43, 1999 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-10510788

RESUMO

Aplidine (dehydrodidemnin B) is a new marine-derived depsipeptide with a powerful cytotoxic activity, which is under early clinical investigation in Europe and in the US. In order to investigate the pharmacokinetic properties of this novel drug, an HPLC-tandem mass spectrometry method was developed for the determination of aplidine in biological samples. Didemnin B, a hydroxy analogue, was used as internal standard. After protein precipitation with acetonitrile and extraction with chloroform, aplidine was chromatographed with a RP octadecylsilica column using a water-acetonitrile linear gradient in the presence of formic acid at the flow-rate of 500 microliters/min. The method was linear over a 5-100 ng/ml range (LOD = 0.5 ng/ml) in plasma and over a 1.25-125 ng/ml range (LOD = 0.2 ng/ml) in urine with precision and accuracy below 14.0%. The intra- and inter-day precision and accuracy were below 12.5%. The extraction procedure recoveries for aplidine and didemnin B were 69% and 68%, respectively in plasma and 91% and 87%, respectively in urine. Differences in linearity, LOQ, LOD and recoveries between plasma and urine samples seem to be matrix-dependent. The applicability of the method was tested by measuring aplidine in rat plasma and urine after intravenous treatment.


Assuntos
Antineoplásicos/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Depsipeptídeos , Espectrometria de Massas/métodos , Oligopeptídeos/farmacocinética , Peptídeos Cíclicos , Animais , Antineoplásicos/sangue , Antineoplásicos/urina , Masculino , Oligopeptídeos/sangue , Oligopeptídeos/urina , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
13.
Br J Pharmacol ; 127(3): 747-55, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10401566

RESUMO

1. The effects of ethyl alcohol and wine (red and white) on haemostatic parameters and experimental thrombosis were studied in rats; NO was evaluated as a possible mediator of these effects. 2. We found that red wine (12% alcohol) supplementation (8.4 +/- 0.4 ml d-1 in drinking water, for 10 days) induced a marked prolongation of 'template' bleeding time (BT) (258 +/- 13 vs 132 +/- 13 s in controls; P < 0.001), a decrease in platelet adhesion to fibrillar collagen (11.6 +/- 1.0 vs 32.2 +/- 1.3%; P < 0.01) and a reduction in thrombus weight (1.45 +/- 0.33 vs 3.27 +/- 0.39 mg; P < 0.01). 3. Alcohol-free red wine showed an effect similar to red wine. In contrast, neither ethyl alcohol (12%) nor white wine (12% alcohol) affected these systems. 4. All these effects were also observed after red wine i.v. injection (1 ml kg-1 of 1:4 dilution) 15 min before the experiments. 5. The effects of red wine were prevented by the NO inhibitor, N omega nitro-L-arginine-methyl ester (L-NAME). L-arginine, not D-arginine, reversed the effect of L-NAME on red wine infusion. 6. Red wine injection induced a 3 fold increase in total radical-trapping antioxidant parameter values of rat plasma with respect to controls, while white wine and alcohol did not show any effect. 7. Our study provides evidence that red wine modulates primary haemostasis and prevents experimental thrombosis in rats, independently of its alcohol content, by a NO-mediated mechanism.


Assuntos
Hemostasia/fisiologia , Óxido Nítrico/biossíntese , Trombose/sangue , Trombose/prevenção & controle , Vinho , Administração Oral , Animais , Antioxidantes/metabolismo , Tempo de Sangramento , Modelos Animais de Doenças , Etanol/sangue , Radicais Livres/sangue , Injeções Intravenosas , Masculino , Óxido Nítrico/sangue , Óxido Nítrico/fisiologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Sprague-Dawley , Trombose/metabolismo
15.
Int J Cancer ; 81(5): 761-6, 1999 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-10328230

RESUMO

We have examined the effects of the synthetic matrix metalloproteinase inhibitor, batimastat (BB-94) and the angiotensin-converting enzyme inhibitor, captopril, on metalloproteinase activity of murine Lewis-lung-carcinoma cells (3LL) in vitro, and on local growth and lung metastasis of the same tumor implanted intramuscularly in syngeneic C57BL/6 mice. The effect of BB-94 and captopril on the survival of the 3LL-tumor-bearing mice was also examined. Here we report that captopril treatment resulted in decreased transcription and protein levels of gelatinase A by 3LL cells. Both BB-94 and captopril also prevented substrate degradation by gelatinase A and B released in conditioned medium by cultured cells. Treatment of tumor-bearing animals with BB-94 (i.p.) or captopril (in drinking water) resulted in significant inhibition of the mean tumor volume (25 and 33% respectively) and of the mean lung metastasis number (26 and 29% respectively). When both agents were given, they acted in synergy, resulting in 51 and 80% inhibition of tumor growth and metastasis. The survival time of the mice treated with both BB-94 and captopril was also significantly longer compared with the groups treated with each agent alone or with the vehicle. Our data support the hypothesis of an essential role of metalloproteinase(s) in the metastatic process. Moreover, blockade of invasion, angiogenesis and other processes mediated by metalloproteinases may underlie the anti-tumor and anti-metastatic effect of BB-94 and captopril and their combination. It is conceivable that this combination could be tested in selected clinical conditions as an adjuvant modality to cytotoxic therapy.


Assuntos
Captopril/uso terapêutico , Carcinoma Pulmonar de Lewis/enzimologia , Gelatinases/antagonistas & inibidores , Neoplasias Pulmonares/enzimologia , Metaloendopeptidases/antagonistas & inibidores , Fenilalanina/análogos & derivados , Tiofenos/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Northern Blotting , Western Blotting , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/mortalidade , Carcinoma Pulmonar de Lewis/patologia , Divisão Celular/efeitos dos fármacos , Colagenases/metabolismo , Meios de Cultivo Condicionados/metabolismo , Feminino , Gelatina/metabolismo , Gelatinases/biossíntese , Gelatinases/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Metaloproteinase 2 da Matriz , Metaloproteinase 9 da Matriz , Metaloendopeptidases/biossíntese , Metaloendopeptidases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica/tratamento farmacológico , Transplante de Neoplasias , Fenilalanina/uso terapêutico , Inibidores de Proteases/uso terapêutico , Taxa de Sobrevida
17.
Biochem J ; 335 ( Pt 3): 573-9, 1998 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9794797

RESUMO

The gene coding for a novel glutathione S-transferase (GST) has been isolated from the bacterium Ochrobactrum anthropi. A PCR fragment of 230 bp was obtained using oligonucleotide primers deduced from N-terminal and 'internal' sequences of the purified enzyme. The gene was obtained by screening of a genomic DNA partial library from O. anthropi constructed in pBluescript with a PCR fragment probe. The gene encodes a protein (OaGST) of 201 amino acids with a calculated molecular mass of 21738 Da. The product of the gene was expressed and characterized; it showed GST activity with substrates 1-chloro-2, 4-dinitrobenzene (CDNB), p-nitrobenzyl chloride and 4-nitroquinoline 1-oxide, and glutathione-dependent peroxidase activity towards cumene hydroperoxide. The overexpressed product of the gene was also confirmed to have in vivo GST activity towards CDNB. The interaction of the recombinant GST with several antibiotics indicated that the enzyme is involved in the binding of rifamycin and tetracycline. The OaGST amino acid sequence showed the greatest identity (45%) with a GST from Pseudomonas sp. strain LB400. A serine residue in the N-terminal region is conserved in almost all known bacterial GSTs, and it appears to be the counterpart of the catalytic serine residue present in Theta-class GSTs. Substitution of the Ser-11 residue resulted in a mutant OaGST protein lacking CDNB-conjugating activity; moreover the mutant enzyme was not able to bind Sepharose-GSH affinity matrices.


Assuntos
Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Bactérias Aeróbias Gram-Negativas/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Biblioteca Genômica , Glutationa Transferase/química , Bactérias Aeróbias Gram-Negativas/genética , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Plasmídeos , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
18.
J Toxicol Clin Toxicol ; 36(6): 603-7, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9776966

RESUMO

CASE REPORT: In a 57-year-old female owner of a dry-cleaning shop, we describe the association of severe bilateral optic neuritis with unexpectedly high concentrations of perchloroethylene/metabolites in the blood and of chloroform in urine. Visual disturbances consisted of complete blindness for 9 days in the left eye, for 11 days in the right eye, with bright phosphenes and pain on eye rotation. Only central (2-3 degrees radius) vision recovered in the following months. CONCLUSION: Although environmental concentrations of perchloroethylene were within normal limits, we measured five-fold increases in vapors emitted when ironing freshly dry-cleaned fabrics, and suggest that inhalation of perchloroethylene vapors was the cause of this case of ocular nerve toxicity, recapitulating a previous report of major perchloroethylene toxicity.


Assuntos
Cegueira/induzido quimicamente , Doenças Profissionais/induzido quimicamente , Neurite Óptica/induzido quimicamente , Fosfenos/efeitos dos fármacos , Solventes/intoxicação , Tetracloroetileno/intoxicação , Cegueira/sangue , Cegueira/urina , Clorofórmio/urina , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Doenças Profissionais/sangue , Doenças Profissionais/urina , Tetracloroetileno/sangue
19.
FEMS Microbiol Lett ; 160(1): 81-6, 1998 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9495016

RESUMO

Glutathione transferase was purified from Ochrobactrum anthropi and its N-terminal sequence was determined to be MKLYYKVGACSLAPHIILSEAGLPY. The apparent molecular mass of the protein (24 kDa) was determined by SDS-polyacrylamide gel electrophoresis analysis. The amino acid sequence obtained showed similarities with known bacterial glutathione transferases in the range of 72-64%. Immunoblotting experiments performed with antisera raised against glutathione transferase from O. anthropi did not show cross-reactivity with two bacterial glutathione transferases belonging to Serratia marcescens and Proteus mirabilis.


Assuntos
Glutationa Transferase/genética , Glutationa Transferase/isolamento & purificação , Bactérias Aeróbias Gram-Negativas/enzimologia , Bactérias Aeróbias Gram-Negativas/genética , Especificidade de Anticorpos , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Glutationa Transferase/imunologia , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
20.
Arterioscler Thromb Vasc Biol ; 17(11): 3185-90, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9409309

RESUMO

Matrix metalloproteinases (MMPs) are a multigene family of enzymes secreted by a variety of cells, including human umbilical vein endothelial cells (HUVECs). Because metalloproteinases are potentially destructive agents, their production is tightly controlled at several levels. Rather little is known about the presence and regulation of MMPs in endothelial cells. In this study, we investigated the expression and regulation of MMP-2 and membrane type-matrix metalloproteinase (MT-MMP1), a membrane metalloproteinase strictly related to MMP-2 activation. Zymographic analysis of conditioned medium (CM) of HUVECs showed the presence of gelatinolytic activity mainly at 72 and 64 and 62 kD. The 64- and 62-kD bands, respectively, represent the intermediate and the completely active forms of MMP-2. When HUVECs were treated with forskolin (FK) (100 and 25 mumol/l), there was a decrease in the appearance of the 64 to 62 kDa doublet, suggesting an inhibition of the fully activated form of MMP-2. FK raises intracellular cAMP in HUVECs. The same data were obtained using dibutyryl-cAMP. Northern analysis revealed that the expression of MMP-2 increased slightly after treatment with FK, in contrast with gelatin zymography results. Taking into consideration the mechanism of activation of MMP-2, we tested the hypothesis that this compound could modulate MT-MMP1. As expected, FK was able to decrease MT-MMP1 expression. These data correlate with experiments using membranes of FK-treated HUVECs and incubated with control CM. Zymography revealed that when CM was incubated with membranes prepared from FK-treated HUVECs, there was a decrease in the appearance of the 64-kDa band, suggesting that the expression of MT-MMP1 was negatively modified. These results correlate with the MT-MMP1 protein level, negatively modified after FK treatment.


Assuntos
Colagenases/biossíntese , AMP Cíclico/fisiologia , Endotélio Vascular/enzimologia , Gelatinases/biossíntese , Isoenzimas/biossíntese , Proteínas de Membrana/biossíntese , Metaloendopeptidases/biossíntese , Sistemas do Segundo Mensageiro/fisiologia , Bucladesina/farmacologia , Células Cultivadas , Colforsina/farmacologia , Colagenases/genética , Meios de Cultivo Condicionados/química , Meios de Cultura Livres de Soro , Indução Enzimática , Gelatinases/genética , Humanos , Isoenzimas/genética , Metaloproteinase 1 da Matriz , Metaloproteinase 2 da Matriz , Proteínas de Membrana/genética , Metaloendopeptidases/genética , RNA Mensageiro/biossíntese , Acetato de Tetradecanoilforbol/farmacologia , Veias Umbilicais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...