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1.
Meat Sci ; 157: 107874, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31247383

RESUMO

The main goal of the present study was to clarify the effects of different grinding particle size of grains (2-mm vs. 6-mm) included in complete pelleted diets (CPD) for fattening lambs on animal performance, carcass and meat quality. Twenty male merino lambs (14.8 kg; n = 10 per group) were fed the corresponding diet ad libitum and slaughtered when they reached 27 kg. No differences were observed in the feed conversion ratio or carcass characteristics. However, lambs fed coarser diets (6 mm) were more efficient with less residual feed intake (-14.0 vs. 15.4 g DM/animal/d; P < .05) than lambs fed the 2 mm CPD. Lambs fed the 6-mm CPD showed higher levels of intramuscular fat and saturated fatty acids. Consequently, increasing the particle size of the grains included in CPD allows for improving feed efficiency and intramuscular fat in fattening lambs.


Assuntos
Ração Animal/análise , Tamanho da Partícula , Carne Vermelha/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal , Dieta/veterinária , Grão Comestível , Ácidos Graxos/metabolismo , Masculino , Carneiro Doméstico/metabolismo
2.
Food Chem Toxicol ; 121: 558-565, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30266314

RESUMO

A study on a set of ready-to-eat meals (n = 328) based on cereals, legumes, vegetables, fish and meat was carried out to determine the natural presence of twenty-seven mycotoxins by both liquid chromatography and gas chromatography coupled mass spectrometry in tandem (MS/MS) after QuEChERS extraction. The occurrence of mycotoxins was headed by cereal samples with 35% of samples contaminated by at least one mycotoxin followed by vegetables (32%), legumes (15%) and lastly, 9% of fish and meat samples were contaminated. DON was the most detected mycotoxin in vegetables, meat, fish and cereals with an incidence of 13% 18% 19% and 60%, respectively, and the highest mean levels were found in fish (1.19 µg/kg) and vegetable (1.53 µg/kg), respectively. The highest levels means were for HT-2 toxin ranging from 4.03 to 7.79 µg/kg, in cereal and legume samples respectively. In this last, HT-2 toxin was also the most prevalent (54%). In meat samples, OTA resulted with highest value with 8.09 µg/kg. Likewise, PCA analysis revealed a high correlation between the mycotoxins and the food groups analyzed. The findings indicate that there is no toxicological concern associated with exposure to mycotoxins for consumers as all levels were in accordance with the legislation.


Assuntos
Contaminação de Alimentos/análise , Manipulação de Alimentos , Micotoxinas/química , Animais , Bovinos , Galinhas , Grão Comestível/química , Fabaceae/química , Peixes , Carne/análise , Medição de Risco , Suínos , Verduras/química
3.
Food Res Int ; 111: 342-350, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30007695

RESUMO

Astaxanthin is a natural red carotene exerting a strong antioxidant action. The effect of this carotene on the oxidative stability of raw and cooked lamb patties was evaluated. Seven experimental treatments were included in this study depending on the antioxidants added, which are: no antioxidant added (control), 450 mg/kg of sodium metabisulphite, 500 mg/kg of sodium ascorbate, and 20 mg/kg, 40 mg/kg, 60 mg/kg and 80 mg/kg of astaxanthin. The raw patties were either refrigerated for up to 11 days or frozen for 3 months under aerobic conditions. Changes in thiobarbituric reactive substances (TBARS), instrumental colour, pH and Eh were determined in the refrigerated patties and TBARS in the frozen patties. Volatile compounds were determined in cooked patties and cholesterol oxides in both cooked and after cooking microwave reheated patties. The changes in TBARS of cooked patties during a four-day refrigerated storage were also studied. Compared to the control patties, the use of astaxanthin reduced the TBARS generation in a manner depending on the dose for both raw and cooked patties during storage (P < 0.05). Astaxanthin added at levels of 60 and/or 80 mg/kg showed a greater antioxidant effect than ascorbate and metabisulphite. The presence of astaxanthin, like that of ascorbate, decreased the oxysterols levels of cooked patties with regard to controls. The amount of volatiles released from the cooked patties was also reduced by astaxanthin. This effect was not observed for ascorbate or metabisulphite. Astaxanthin in lamb patties at levels of 60-80 mg/kg could improve raw and cooked lamb patty oxidative stability during refrigerated aerobic storage, protect their lipids against thermal degradation more than ascorbate and metabisulphite, and reduce oxysterols formation during cooking in a similar way to ascorbate.


Assuntos
Antioxidantes/farmacologia , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Produtos da Carne/análise , Carne Vermelha/análise , Animais , Culinária , Congelamento , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Ovinos , Tempo , Xantofilas/farmacologia
4.
Animal ; 12(5): 1093-1101, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28965526

RESUMO

Suckling lamb meat is traditionally produced in Mediterranean Europe. Breed can affect the quality of the lamb carcass and meat. This study is aimed at comparing the carcass and meat quality between suckling lambs from a local and a non-native dairy breed, Churra and Assaf. Churra is included in the Spanish Protected Geographical Indication (PGI) 'Lechazo de Castilla y León', whereas Assaf is not. However, Assaf breeders have requested the inclusion of the breed in the PGI. Carcasses and meat from 16 male lambs (eight Churra and eight Assaf) were used in this study. The lambs were all raised under an intensive rearing system and fed on a milk substitute to minimise maternal influence. The carcasses were evaluated for conformation, fatness, joint and leg tissue proportions and the meat was analysed for composition (i.e. proximate composition, iron, haematin, fatty acids and volatiles) and technological quality traits (i.e. texture, water holding capacity, colour and lipid stability). Churra carcasses were larger than Assaf carcasses. However, the proportions of commercial joints and main tissues did not differ between breeds. Cavity and intermuscular leg fat, but not total leg fat, were higher in Churra carcasses. Churra meat showed a higher proportion of n-6 fatty acids, higher redness and better colour stability during aerobic storage. In contrast, Assaf lamb was more resistant to lipid oxidation after cooking. This is a preliminary study to measure the influence of breed on a wide range of quality characteristics in Churra and Assaf suckling lamb carcass and meat. It may be of relevance for breeders, consumers and food policy makers, setting the basis for future studies that include larger commercial populations.


Assuntos
Ácidos Graxos/metabolismo , Leite/metabolismo , Carne Vermelha/análise , Ovinos/fisiologia , Animais , Masculino , Carne Vermelha/normas
5.
Rev. toxicol ; 35(1): 2-6, 2018. tab, graf
Artigo em Inglês | IBECS | ID: ibc-176858

RESUMO

A study on fruit juice products (apple, pineapple, apricot, orange and pear) was carried out to determine the natural occurrence of fifteen mycotoxins by gas chromatography coupled to tandem mass spectrometry (MS/MS). A developed multi-mycotoxin procedure was carried out by dispersive liquid-liquid microextraction (DLLME). 36% of the analyzed samples presented mycotoxin contamination. PAT was detected in orange, apple, mixed fruits and pineapple juices with prevalence of 86%, 60%, 29%, 14% at mean concentrations of 34.57 µg/L, 33.41 µg/L, 8.59 µg/L, 8.02 µg/L, respectively. One orange juice sample, exceeded the maximum level (ML) established by EU for PAT (50 µg/L). HT-2 toxin was found in mixed juice (43%) at mean level of 22.38 µg/L. Overall no toxicological concern was associated to mycotoxins exposure for children and adult population and the results obtained highlight the necessity for rigorous monitoring studies on HT-2 in fruit juice


Se presenta un estudio sobre zumos de frutas a base de manzana, piña, albaricoque, naranja y pera para determinar la presencia natural de quince micotoxinas mediante cromatografía de gases acoplada a espectrometría de masas en tándem (EM/EM). El procedimiento desarrollado de multi-micotoxinas se llevó a cabo mediante micro-extracción líquida-líquida dispersiva (DLLME). El 36% de las muestras analizadas presentaron contaminación con micotoxinas y una muestra de jugo de naranja, superó el nivel máximo (ML) establecido por la UE para PAT (50 μg/L). Se detectó PAT en naranja, manzana, frutas mezcladas y jugos de piña con una prevalencia de 86%, 60%, 29%, 14% a concentraciones promedio de 34.57 μg/L, 33.41 μg/L, 8.59 μg/L, 8.02 μg/L, respectivamente. La toxina HT-2 estaba presente en el jugo mixto (43%) a un nivel medio de 22.38 μg/L. En general, ninguna preocupación toxicológica se asoció con la exposición a micotoxinas en la población de niños y adultos, los resultados ponen de relieve la necesidad de estudios rigurosos de monitoreo de HT-2 en el zumo de fruta


Assuntos
Humanos , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Micotoxinas/isolamento & purificação , Cromatografia Gasosa/métodos , Amostras de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Sucos de Frutas e Vegetais/análise
7.
Sleep Med ; 15(3): 322-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24468102

RESUMO

BACKGROUND: Nighttime traffic noise is associated with sleep disturbances, but sleep fragmentation and sleep-disordered breathing (SDB) have not been demonstrated in individuals living near busy roads. METHODS: We asked 1383 participants to answer a health questionnaire and to undergo 24-h electrocardiogram (ECG). Nocturnal ECG records were used to calculate the very low frequency index (VLFI) interval, a surrogate marker of sleep fragmentation. Distances of participants' addresses to roadways were calculated using the VECTOR25© Swisstopo roads classification, a traffic noise proxy. Distances of homes within 100 or 50 m of major roads defined proximity to busy roads. Adjusted multivariate logistic regressions analyzed associations between the distance of home to main roads and VLFI or self-reported SDB. RESULTS: Distance of participants' homes to main roads was significantly associated with the VLFI in women (odds ratio [OR], 1.58 [confidence interval {CI}, 1.03-2.42]; P = .038) but not in men (OR, 1.35 [CI, 0.77-2.35]; P = .295). Women under hormonal replacement therapy (HRT) were at higher risk for increased VLFI when living close to main roads (OR, 2.10 [CI, 1.20-3.68]; P = .01) than untreated women (P = .584). Associations with self-reported SDB were not statistically relevant. CONCLUSIONS: In our large population, women living close to main roads were at significantly higher risk for sleep fragmentation than men. The 2-fold higher risk for menopausal women under HRT underscores the vulnerability of this group.


Assuntos
Veículos Automotores , Ruído/efeitos adversos , Síndromes da Apneia do Sono/etiologia , Privação do Sono/etiologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Fatores Sexuais , Inquéritos e Questionários
8.
Rev Med Suisse ; 8(358): 1966-8, 1970-1, 2012 Oct 17.
Artigo em Francês | MEDLINE | ID: mdl-23198650

RESUMO

Despite progress in medical and surgical treatment, morbidity and mortality remain high in infective endocarditis. Multiple diagnostic tools are now available to decrease delays in the diagnosis and instauration of appropriate treatment. Identification of patients at high risk of developing complications and those who may benefit from early surgery could improve prognosis and outcome. This article reviews some of the existing tools and options available for the diagnosis, risk evaluation and treatment of infective endocarditis, as well as the evidence for their systematic use.


Assuntos
Diagnóstico Precoce , Endocardite/diagnóstico , Endocardite/terapia , Antibacterianos/uso terapêutico , Diagnóstico por Imagem , Humanos , Medição de Risco
9.
Rev Med Suisse ; 7(297): 1200-2, 1204-6, 2011 Jun 01.
Artigo em Francês | MEDLINE | ID: mdl-21717693

RESUMO

Contrary to the decline in the prevalence of several risk factors such as hypertension, hypercholesterolemia and smoking, diabetes is an expanding health burden in the western world. Because of the proatherosclerotic, proinflammatory, and prothrombotic states associated with diabetes, diabetic patients with acute coronary syndromes (ACS) are at high risk of subsequent cardiovascular events. However, they derive greater benefit from aggressive platelet inhibition and an early invasive strategy than non-diabetic individuals. Despite the documented efficacy, diabetic patients with ACS receive evidence-based treatments less frequently than non-diabetic individuals.


Assuntos
Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/tratamento farmacológico , Complicações do Diabetes/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Síndrome Coronariana Aguda/fisiopatologia , Síndrome Coronariana Aguda/terapia , Algoritmos , Angioplastia , Anti-Inflamatórios não Esteroides/uso terapêutico , Clopidogrel , Complicações do Diabetes/fisiopatologia , Complicações do Diabetes/terapia , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus/terapia , Quimioterapia Combinada , Enoxaparina/uso terapêutico , Medicina Baseada em Evidências , Fibrinolíticos/uso terapêutico , Heparina/uso terapêutico , Humanos , Hipoglicemiantes/uso terapêutico , Piperazinas/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Cloridrato de Prasugrel , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Prevenção Secundária/métodos , Stents , Tiofenos/uso terapêutico , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico , Resultado do Tratamento
10.
Allergy ; 66(9): 1242-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21605124

RESUMO

BACKGROUND: TPI ASM8 contains two modified antisense oligonucleotides (AON) targeting the beta subunit (ß(c) ) of the IL-3, IL-5, GM-CSF receptors and the chemokine receptor CCR3. A previous study suggested that TPI ASM8 had broader effects than just inhibition of eosinophils in asthmatics. OBJECTIVE: We assessed whether TPI ASM8 caused a dose-dependent attenuation in the inflammatory and physiological changes after inhaled allergen challenge (AIC). METHODS: This single-center, open-label, stepwise-ascending dose study was conducted in fourteen stable, mild allergic asthmatics. Following placebo AIC, subjects underwent AIC after 4 days treatment with 1, 2, and 4 mg BID and finally 8 mg once daily (OD) of TPI ASM8, inhaled via the I-Neb™ nebuliser. Treatments were separated by 2-3-week washout periods. RESULTS: TPI ASM8 was safe and well tolerated at all doses. TPI ASM8 8 mg OD reduced eosinophils in sputum after AIC (by 60.9% at 7 h and 68.4% at 24 h post-AIC, P=0.016 and P=0.007, respectively). Additionally, TPI ASM8 8 mg OD significantly attenuated the early and late airway responses as shown by the reduction in the area under the curve by 45% (P=0.016) and 59%, (P=0.0015), respectively, the increase in eosinophil cationic protein (ECP) by up to 57% (P=0.021), and airway responsiveness to methacholine by more than 1 doubling dose (P=0.012). A dose-response relationship was noted, and efficacy was maintained with once per day administration. CONCLUSIONS: TPI ASM8 attenuated a broad range of inflammatory and physiological changes after AIC, suggesting that CCR3, IL-3, and GM-CSF also are important targets for the management of asthma.


Assuntos
Alérgenos/imunologia , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Asma/imunologia , Oligonucleotídeos Fosforotioatos/uso terapêutico , Adolescente , Adulto , Alérgenos/administração & dosagem , Antiasmáticos/administração & dosagem , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacocinética , Asma/genética , Subunidade beta Comum dos Receptores de Citocinas/genética , Relação Dose-Resposta a Droga , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Oligonucleotídeos Fosforotioatos/administração & dosagem , Oligonucleotídeos Fosforotioatos/efeitos adversos , Oligonucleotídeos Fosforotioatos/farmacocinética , RNA Mensageiro/genética , Receptores CCR3/genética , Hipersensibilidade Respiratória/tratamento farmacológico , Hipersensibilidade Respiratória/imunologia , Escarro/imunologia , Adulto Jovem
11.
Int J Clin Pharmacol Ther ; 48(10): 670-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20875373

RESUMO

OBJECTIVES: Polyisoprenylated acylphloroglucinols have recently emerged as antitumoral agents. This study aims at elucidating the antiretroviral activity of two such compounds which were isolated from Caribbean propolis: 7-epi-nemorosone and plukenetione A, the structure of which is based on an adamantane moiety. Plukenetione A is for the first time shown to have antiretroviral activity. MATERIAL AND METHODS: The isolation of both small molecules was carried out using RP-HPLC. Their antiretroviral activity was studied based on lentiviral particles produced in HEK293T cells from the SIV-based vector VLDBH; their cytotoxicity was monitored by MTT proliferation assay. The antiviral activity of 7-epi-nemorosone was studied in CEMx174-SEAP infected with the HIV-1-strain pNL4.3wt. Reverse transcriptase inhibition was determined by a standard two-step RT-PCR using MMLV RT. RESULTS: 7-epi-nemorosone and plukenetione A were found to be potent antilentiviral agents in the employed system, inhibiting viral infection at concentrations below 1 µM/2 µM, respectively. Whereas 7-epi-nemorosone was not able to inhibit the reverse transcriptase in vitro (IC50 > 25 µM), plukenetione A effectively inhibited its enzymatic activity at an IC50 of 1.75 µM. CONCLUSIONS: Despite 7-epi-nemorosone and plukenetione A sharing some structural core elements, the mechanism of action involved in their antiretroviral activity seems to be different. We propose that 7-epi-nemorosone inhibits the viral replication by interrupting the Akt/PKB signaling cascade, as was demonstrated previously in various cell lines. Since plukenetione A effectively inhibits the enzymatic activity of MMLV reverse transcriptase at concentrations that show antilentiviral activity, we suggest that this small molecule acts by interfering with the enzyme's catalytic site.


Assuntos
Antivirais/farmacologia , Benzofenonas/farmacologia , Lentivirus/efeitos dos fármacos , Compostos Policíclicos/farmacologia , Própole/química , Benzofenonas/química , Região do Caribe , Células Cultivadas , HIV-1/efeitos dos fármacos , Humanos , Compostos Policíclicos/química
12.
Minerva Med ; 101(2): 81-104, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20467408

RESUMO

Contrary to the decline in the prevalence of several risk factors such as hypertension, hypercholesterolemia and smoking, diabetes is an expanding health burden in the Western world. Because of the proatherosclerotic, proinflammatory, and prothrombotic states associated with diabetes, diabetic patients with acute coronary syndromes (ACS) are at high risk of subsequent cardiovascular events. However, they derive at the same time greater benefit from evidence-based therapy than the non-diabetic individuals. The two mainstays of acute ACS therapy for diabetic patients are an aggressive platelet inhibition and an early invasive strategy. Aspirin should be administered in all patients and prasugrel is to be considered superior to clopidogrel in this setting. While the use of glycoprotein IIb/IIIa receptor inhibitors in the diabetic ACS population has been associated with a mortality reduction, the role of these agents in the prasugrel era remains to be elucidated. Importantly, the aggressiveness of anti-thrombotic therapy should be balanced in each individual patient with the risk of bleeding. The benefit of early coronary angiography and, if needed, revascularization, in the setting of non-ST-segment elevation ACS is more pronounced in diabetic than in non-diabetic individuals. All patients, diabetics and non-diabetics, qualify for primary percutaneous coronary intervention (PCI) as the therapy of choice for ST-segment elevation myocardial infarction. In order to reduce hemorrhagic complications related to vascular access for PCI, the radial approach should be favored. Additional important secondary preventive measures include high-dose statin therapy, ACE-Inhibition/angiotensin II receptor blockade, and adequate glucose metabolism control. Despite the documented efficacy, diabetic patients with ACS receive evidence-based treatments less frequently than non-diabetic individuals.


Assuntos
Síndrome Coronariana Aguda/terapia , Angioplastia Coronária com Balão , Angiopatias Diabéticas/terapia , Infarto do Miocárdio/terapia , Inibidores da Agregação Plaquetária/uso terapêutico , Síndrome Coronariana Aguda/fisiopatologia , Anticoagulantes/uso terapêutico , Angiopatias Diabéticas/fisiopatologia , Endotélio Vascular/fisiopatologia , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Humanos , Hipoglicemiantes/uso terapêutico , Piperazinas/uso terapêutico , Inibidores da Agregação Plaquetária/efeitos adversos , Cloridrato de Prasugrel , Tiofenos/uso terapêutico
14.
Int J Clin Pharmacol Ther ; 46(8): 428-39, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18793585

RESUMO

OBJECTIVE: This work is aimed at characterizing nemorosone, isolated from Clusia rosea, as a potential antileukemic agent. In addition, we analyzed its influence on hematopoiesis in a mouse model. MATERIALS AND METHODS: The isolation of nemorosone was carried out employing the RP-HPLC (reversed phase high-performance liquid chromatography) technique. Cytotoxicity was assessed in human leukemia cell lines including parental and chemotherapy-refractory sublines based on the MTT compound. Its effects on the cell cycle were analyzed using FACS (fluorescence-activated cell sorting) and Western blot techniques. Studies on the drug-induced early apoptotic process were carried out by means of fluorescence microscopy. Major signal transducers and the enzymatic inhibition of immunoprecipitated Akt/PKB were detected by Western blot. Hematopoiesis was analyzed in NMRI nu/nu mice after chronic nemorosone treatment, measuring hematological parameters by conventional laboratory techniques. RESULTS: Nemorosone proved cytotoxic in both parental and chemoresistant leukemia cell lines with IC50 values between 2.10 and 3.10 mg/ml. No cross-resistances could be detected. Cell cycle studies showed apoptosis induction accompanied by an increase in the G0/G1 population in both cell lines studied, whereas a significant decrease in the S-phase was found in Jurkat cells. Nemorosone induced a down-regulation of cyclins A, B1, D1, and E as well as a dephosphorylation of cdc2. Major signal transduction elements such as ERK1/2 and p38 MAPK, as well as important oncoproteins such as c-Myb and BCR/ABL were also found down-regulated. The enzymatic activity of immunoprecipitated Akt/PKB was substantially inhibited in vitro. Moreover, subchronic nemorosone treatment induced reversible monocytosis and thrombocytosis in the mouse model examined. CONCLUSIONS: Here, we demonstrate for the first time that nemorosone exerts cytotoxicity in leukemia cells, partly by targeting the Akt/PKB signal transducer, affecting protein levels and cell cycle progression. Finally, in vivo studies suggest that nemorosone significantly affects hematopoiesis in mice.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Benzofenonas/farmacologia , Clusia/química , Leucemia/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Benzofenonas/administração & dosagem , Benzofenonas/isolamento & purificação , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Feminino , Hematopoese/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Leucemia/patologia , Camundongos , Camundongos Nus , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
Int J Clin Pharmacol Ther ; 46(5): 226-35, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18538108

RESUMO

OBJECTIVE: Mucronulatol is one of the most cytotoxic substances present in Caribbean propolis. This work aimed at initially characterizing the biological effects of mucronulatol in cancer cell lines comprehending both wildtype and resistant sublines. MATERIALS AND METHODS: An RP-HPLC technique was employed to separate and purify mucronulatol. IC(50) values were determined using the sulforhodamine B (SRB) proliferation assay. FACS-based cell cycle studies were carried out combining propidium iodide staining and 5-bromo-2'-deoxyuridine incorporation. Cell cycle regulator proteins were detected by Western blotting. The transcription of genes of interest was analyzed using RT-PCR. RESULTS: In MDR1-/MDR3+ cells, mucronulatol exhibited cytotoxicity in the range of 2.7 - 10.2 microg/ml, while no cytotoxic effects were observed in MDR1+ systems at up to 100 microg/ml. Cytometric studies revealed that mucronulatol promoted a global reduction in all cell cycle phases, with a remarkable increase of the apoptotic sub-G1 population. Immunoblotting showed that mucronulatol induced an up-regulation of p21(Cip1) and p27(Kip1) while down-regulating cyclin E and CDK4 in a drug concentration-dependent manner. No effect on topoisomerase I was observed, while we detected an altered expression of topoisomerases II-I+/-/I(2). RT-PCR studies showed that 2-fold the IC(50) in HCT8 colon carcinoma cells was sufficient for altering the expression pattern of genes in this cell line, including topoisomerase I, thymidilate synthase, EGF receptor and c-myc, amongst others. CONCLUSION: Here, we demonstrate for the first time that mucronulatol exerts cytotoxicity in cancer cell lines by targeting the control of cell cycle progression, indicating that the mechanism of action of this compound involves interference with the cell cycle machinery.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Indigofera , Isoflavonas/isolamento & purificação , Isoflavonas/farmacologia , Antineoplásicos/química , Western Blotting , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Resistencia a Medicamentos Antineoplásicos , Humanos , Isoflavonas/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Índias Ocidentais
16.
J Cell Mol Med ; 12(6B): 2598-608, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18194446

RESUMO

Neuroblastoma is the second most common solid tumour during childhood, characterized by rapid disease progression. Most children with metastasized neuroblastoma die despite intensive chemotherapy due to an intrinsic or acquired chemotherapy resistance. Thus, new therapeutic strategies are urgently needed. Here, we demonstrate that the novel compound nemorosone isolated from alcoholic extracts of Clusia rosea resins by reverse phase high pressure liquid chromatography (RP-HPLC) exerts cytotoxic activity in neuroblas-toma cell lines both parental and their clones selected for resistance against adriamycin, cisplatin, etoposide or 5-fluorouracil. Cell cycle studies revealed that nemorosone induces an accumulation in G0/G1- with a reduction in S-phase population combined with a robust up-regulation of p21Cip1. Furthermore, a dose-dependent apoptotic DNA laddering accompanied by an activation of caspase-3 activity was detected. Nemorosone induced a significant dephosphorylation of ERK1/2 in LAN-1 parental cells probably by the inhibition of its upstream kinase MEK1/2. No significant modulation of signal transducers JNK, p38 MAPK and Akt/PKB was detected. The enzymatic activity of immunoprecipitated Akt/PKB was strongly inhibited in vitro, suggesting that nemorosone exerts its anti-proliferative activity at least in part by targeting Akt/PKB in the cell lines studied. In addition, a synergistic effect with Raf-1 inhibitor BAY 43-9006 was found. Finally, nemorosone induced a considerable down-regulation of N-myc protein levels in parental LAN-1 and an etoposide resistant sub-line at the same drug-concentrations.


Assuntos
Benzofenonas/farmacologia , Neuroblastoma/patologia , Benzofenonas/isolamento & purificação , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Ativação Enzimática/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Proteína Proto-Oncogênica N-Myc , Neuroblastoma/enzimologia , Proteínas Nucleares/metabolismo , Proteínas Oncogênicas/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-raf/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
19.
Heart ; 88(4): 363-7, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12231593

RESUMO

OBJECTIVE: To study the role of echocardiography in the stepwise evaluation of syncope. DESIGN: A prospective observational study with an 18 month follow up. SETTING: University teaching hospital providing primary and tertiary care. SUBJECTS: 650 consecutive patients with syncope and clinical suspicion of an obstructive valvar lesion, or with syncope not explained by history, physical examination, or a 12 lead ECG, who underwent bidimensional Doppler transthoracic echocardiography. MAIN OUTCOME MEASURES: The causes of syncope were assigned using published diagnostic criteria. Echocardiography was considered diagnostic when confirming a suspected diagnosis, or when revealing occult cardiac disease explaining the syncope. RESULTS: A systolic murmur was identified in 61 of the 650 patients (9%). Severe aortic stenosis was suspected in 20 of these and was confirmed by echocardiography in eight. Follow up excluded further cases of aortic stenosis. In patients with unexplained syncope (n = 155), routine echocardiography showed no abnormalities that established the cause of the syncope. Echocardiography was normal or non-relevant in all patients with a negative cardiac history and a normal ECG (n = 67). In patients with a positive cardiac history or an abnormal ECG (n = 88), echocardiography showed systolic dysfunction (left ventricular ejection fraction < or = 40%) in 24 (27%) and minor non-relevant findings in the remaining 64. Arrhythmias were diagnosed in 12 of the 24 patients with systolic dysfunction (50%), and in 12 of the 64 remaining patients (19%) (p < 0.01). CONCLUSIONS: Echocardiography was most useful for assessing the severity of the underlying cardiac disease and for risk stratification in patients with unexplained syncope but with a positive cardiac history or an abnormal ECG.


Assuntos
Ecocardiografia , Cardiopatias/diagnóstico por imagem , Síncope/diagnóstico por imagem , Idoso , Feminino , Seguimentos , Cardiopatias/complicações , Humanos , Masculino , Estudos Prospectivos , Síncope/etiologia
20.
Am J Med ; 111(3): 177-84, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11530027

RESUMO

PURPOSE: To determine the diagnostic yield of a standardized sequential evaluation of patients with syncope in a primary care teaching hospital. PATIENTS AND METHODS: All consecutive patients who presented to the emergency department with syncope as a chief complaint were enrolled. Their evaluation included initial and routine clinical examination, including carotid sinus massage, as well as electrocardiography and basic laboratory testing. Targeted tests, such as echocardiography, were used when a specific entity was suspected clinically. Other cardiovascular tests (24-hour Holter monitoring, ambulatory loop recorder ECG, upright tilt test, and signal-averaged electrocardiography) were performed in patients with unexplained syncope after the initial steps. Electrophysiologic studies were performed in selected patients only as clinically appropriate. Follow-up information on recurrence and mortality were obtained every 6 months for as long as 18 months for 94% (n = 611) of the patients. RESULTS: After the initial clinical evaluation, a suspected cause of syncope was found in 69% (n = 446) of the 650 patients, including neurocardiogenic syncope (n = 234, 36%), orthostatic hypotension (n = 156, 24%), arrhythmia (n = 24, 4%), and other diseases (n = 32, 5%). Of the 67 patients who underwent targeted tests, suspected diagnoses were confirmed in 49 (73%) patients: aortic stenosis (n = 8, 1%), pulmonary embolism (n = 8, 1%), seizures/stroke (n = 30, 5%), and other diseases (n = 3). Extensive cardiovascular workups, which were performed in 122 of the 155 patients in whom syncope remained unexplained after clinical assessment, provided a suspected cause of syncope in only 30 (25%) patients, including arrhythmias in 18 (60%), all of whom had abnormal baseline ECGs. The 18-month mortality was 9% (n = 55, including 8 patients with sudden death); syncope recurred in 15% (n = 95) of the patients. CONCLUSION: The diagnostic yield of a standardized clinical evaluation of syncope was 76%, greater than reported previously in unselected patients. Electrocardiogram-based risk stratification was useful in guiding the use of specialized cardiovascular tests.


Assuntos
Síncope/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/diagnóstico , Diagnóstico Diferencial , Eletrocardiografia Ambulatorial , Eletrofisiologia , Feminino , Hospitais de Ensino , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Atenção Primária à Saúde , Estudos Prospectivos , Embolia Pulmonar/diagnóstico , Recidiva , Convulsões/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Síncope/mortalidade , Teste da Mesa Inclinada
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