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1.
Animal ; 18(5): 101158, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38703756

RESUMO

The transformation of pastures from a degraded state to sustainable productivity is a major challenge in tropical livestock production. Stoloniferous forage legumes such as Arachis pintoi (forage peanut) are one of the most promising alternatives for intensifying pasture-based beef livestock operations with reduced greenhouse gas (GHG) emissions. This 2-year study assessed beef cattle performance, nutrient intake and digestibility, and balance of GHG emissions in three pasture types (PT): (1) mixed Palisade grass - Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster (syn. Brachiaria brizantha Stapf cv. Marandu) and forage peanut (A. pintoi Krapov. & W.C. Greg. cv. BRS Mandobi) pastures (Mixed), (2) monoculture Palisade grass pastures with 150 kg of N/ha per year (Fertilised), and (3) monoculture Palisade grass without N fertiliser (Control). Continuous stocking with a variable stocking rate was used in a randomised complete block design, with four replicates per treatment. The average daily gain and carcass gain were not influenced by the PT (P = 0.439 and P = 0.100, respectively) and were, on average, 0.433 kg/animal per day and 83.4 kg/animal, respectively. Fertilised and Mixed pastures increased by 102 and 31.5%, respectively, the liveweight gain per area (kg/ha/yr) compared to the Control pasture (P < 0.001). The heifers in the Mixed pasture had lower CH4 emissions (g/animal per day; P = 0.009), achieving a reduction of 12.6 and 10.1% when compared to the Fertilised and Control pastures, respectively. Annual (N2O) emissions (g/animal) and per kg carcass weight gain were 59.8 and 63.1% lower, respectively, in the Mixed pasture compared to the Fertilised pasture (P < 0.001). Mixed pasture mitigated approximately 23% of kg CO2eq/kg of carcass when substituting 150 kg of N/ha per year via fertiliser. Mixed pastures with forage peanut are a promising solution to recover degraded tropical pastures by providing increased animal production with lower GHG emissions.


Assuntos
Ração Animal , Criação de Animais Domésticos , Arachis , Gases de Efeito Estufa , Animais , Bovinos/fisiologia , Ração Animal/análise , Gases de Efeito Estufa/análise , Criação de Animais Domésticos/métodos , Dieta/veterinária , Masculino , Feminino , Fenômenos Fisiológicos da Nutrição Animal , Digestão , Fabaceae
2.
Mini Rev Med Chem ; 12(12): 1239-49, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22512558

RESUMO

Osteosarcoma is the most common primary bone tumor in children and adolescents, with a 5-year disease free survival rate of 70%. Current chemotherapy regimens comprise a group of chemotherapeutic agents in which doxorubicin is included. However, tumor resistance to anthracyclines and cardiotoxicity are limiting factors for its usage. Liposomal formulations of doxorubicin improve its anti-cancer effects but are still insufficient. The research in this area has lead to the production of anthracyclines analogues, such as ladirubicin, the leading compound of alkylcyclines. This new anticancer agent has shown promising results in vivo and in vitro, being effective against osteosarcoma cell lines, including those with a multidrug resistant phenotype. In phase I clinical trials, this molecule caused mild side effects and did not induce significant cardiotoxicity at doses ranging from 1 to 16 mg/m(2), resulting in a peak plasma concentration (C(max)) ranging from 0.5 to 1.5 µM. The recommended doses for phase II studies were 12 and 14 mg/m(2) in heavily and minimally pretreated/non-pretreated patients, respectively. Phase II clinical trials in ovary, breast, colorectal cancer, NSCLC and malignant melanoma are underway. Given the improved molecular targeting efficacy of these new compounds, ongoing approaches have sought to improve drug delivery systems, to improve treatment efficacy while reducing systemic toxicity. The combination of these two approaches may be a good start for the discovery of new treatment for osteosarcoma.


Assuntos
Antraciclinas/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Daunorrubicina/análogos & derivados , Doxorrubicina/uso terapêutico , Osteossarcoma/tratamento farmacológico , Antraciclinas/química , Antraciclinas/farmacologia , Antineoplásicos/química , Neoplasias Ósseas/química , Linhagem Celular Tumoral , Ensaios Clínicos como Assunto , Daunorrubicina/química , Daunorrubicina/uso terapêutico , Daunorrubicina/toxicidade , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos
3.
Food Chem Toxicol ; 50(6): 2128-34, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22459130

RESUMO

Grilling muscle foods involves high temperatures that lead to production of cooking toxicants, such as heterocyclic aromatic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs). To obtain realistic exposure levels of these two groups of mutagens analyses of the same samples using similar separation/detection techniques were performed. HAs and PAHs were quantified in well-done meat and fish samples grilled with wood and coconut shell charcoal at 200°C. Quantitative HAs and PAHs profiles were different for beef and salmon using the same type of charcoal. Higher levels of HAs and PAHs were found in salmon samples. No significant differences were observed for HAs and PAHs in beef samples grilled with both charcoal types, whereas salmon grilled with coconut shell charcoal presented significantly lower amounts of HAs and PAHs than salmon grilled with usual wood charcoal. Continuous barbecuing with the same charcoal shown that combustion of fat that dropped along the grilling period contributed to higher formation of HAs and PAHs. Special attention must be given to the intake of barbecued foods since high amounts of HAs and PAHs can be taken in a single meal.


Assuntos
Carcinógenos/análise , Carvão Vegetal , Culinária , Compostos Heterocíclicos/análise , Carne , Músculo Esquelético/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Animais , Bovinos , Galinhas , Cocos , Peixes , Temperatura Alta , Indicadores e Reagentes , Peso Molecular , Padrões de Referência , Salmão , Salmonidae , Temperatura , Madeira
4.
Bull Environ Contam Toxicol ; 87(3): 312-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21681400

RESUMO

Infiltration galleries are among the oldest known means used for small public water fountains. Owing to its ancestral origin they are usually associated with high quality water. Thirty-one compounds, including pesticides and estrogens from different chemical families, were analysed in waters from infiltration galleries collected in Alto Douro Demarcated Wine region (North of Portugal). A total of twelve compounds were detected in the water samples. Nine of these compounds are described as presenting evidence or potential evidence of interfering with the hormone system of humans and wildlife. Although concentrations of the target analytes were relatively low, many of them below their limit of quantification, four compounds were above quantification limit and two of them even above the legal limit of 0.1 µg/L: dimethoate (30.38 ng/L), folpet (64.35 ng/L), terbuthylazine-desethyl (22.28 to 292.36 ng/L) and terbuthylazine (22.49 to 369.33 ng/L).


Assuntos
Drenagem Sanitária , Disruptores Endócrinos/análise , Monitoramento Ambiental , Praguicidas/análise , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Animais , Animais Selvagens , Dimetoato/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Ftalimidas/análise , Portugal , Medição de Risco , Triazinas/análise , Abastecimento de Água/normas
5.
J Chromatogr A ; 1217(43): 6681-91, 2010 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-20553685

RESUMO

A multi-residue methodology based on a solid phase extraction followed by gas chromatography-tandem mass spectrometry was developed for trace analysis of 32 compounds in water matrices, including estrogens and several pesticides from different chemical families, some of them with endocrine disrupting properties. Matrix standard calibration solutions were prepared by adding known amounts of the analytes to a residue-free sample to compensate matrix-induced chromatographic response enhancement observed for certain pesticides. Validation was done mainly according to the International Conference on Harmonisation recommendations, as well as some European and American validation guidelines with specifications for pesticides analysis and/or GC-MS methodology. As the assumption of homoscedasticity was not met for analytical data, weighted least squares linear regression procedure was applied as a simple and effective way to counteract the greater influence of the greater concentrations on the fitted regression line, improving accuracy at the lower end of the calibration curve. The method was considered validated for 31 compounds after consistent evaluation of the key analytical parameters: specificity, linearity, limit of detection and quantification, range, precision, accuracy, extraction efficiency, stability and robustness.


Assuntos
Disruptores Endócrinos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Análise dos Mínimos Quadrados , Praguicidas/análise , Poluentes Químicos da Água/análise , Estabilidade de Medicamentos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Eur Respir J ; 17(5): 934-8, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11488329

RESUMO

The following study was undertaken in order to determine how exhaled nitric oxide (eNO) levels in former smokers with chronic obstructive pulmonary disease (COPD) compared to eNO levels in patients with asthma and in healthy nonsmoking volunteers. The study also aimed to determine any relationship between eNO levels in COPD and: 1) conventional measures of lung function; and 2) inhaled corticosteroid (ICS) use. In former smokers with COPD, nonsmokers with asthma and volunteers, eNO levels, spirometry, lung volumes, carbon monoxide diffusion capacity of the lung (DL,CO) and resting oxygen saturation (Sa,O2) were measured. Median eNO was significantly higher among patients with COPD than among healthy volunteers (p = 0.003) but lower than among patients with asthma (p < 0.01). There was no significant difference in eNO levels between COPD patients using ICS and those not using ICS. By contrast, eNO was lower among asthma patients who used ICS (median 32 parts per billion (ppb); 25-75% range 16-54) than among asthma patients who did not (51 ppb; 32-87) (p = 0.034). Among patients with COPD, eNO was inversely correlated with forced expiratory volume in one second, DL,CO and Sa,O2, and was positively correlated with the residual lung volume/total lung capacity ratio. Among patients with asthma, no significant correlations were found. Exhaled nitric oxide is increased in patients with chronic obstructive pulmonary disease, an increase that is influenced by structural abnormalities of tobacco-induced lung damage.


Assuntos
Testes Respiratórios , Medidas de Volume Pulmonar , Óxido Nítrico/análise , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Administração por Inalação , Corticosteroides/administração & dosagem , Adulto , Idoso , Asma/diagnóstico , Asma/tratamento farmacológico , Asma/fisiopatologia , Gasometria , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Capacidade de Difusão Pulmonar/efeitos dos fármacos , Capacidade de Difusão Pulmonar/fisiologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Valores de Referência , Fumar/efeitos adversos
7.
Neurobiologia ; 57(1): 13-8, jan.-mar. 1994.
Artigo em Português | LILACS | ID: lil-154565

RESUMO

A síndrome da morte súbita infantil, ou morte durante o sono, se dá em uma criança normal, após adormecer bem, sem causa aparente. É considerada, como a causa isolada, a mais frequente de morte no primeiro ano de vida, em estatísticas do exterior. Acredita-se ocorrer a morte por um distúrbio funcional dos centros respiratórios levando à apnéia. Em crianças encontradas flácidas em apnéia reversível após estimulaçäo ou ao despertar, denomina-se em "risco" da morte súbita infantil. Apresentamos um caso desta síndrome, com crises de cianose e apnéia durante o sono a partir do oitavo dia de vida. O paciente foi internado, feita a monitorizaçäo respiratória, submetido a registro polissonográfico de 24 horas. Näo foram detectadas causas justificando as apnéias. Foi medicado com aminofilina e constatou-se o desaparecimento das crises de apnéias no segundo mês de vida. Este trabalho permite evidenciar um caso de entidade pouco diagnosticada em nosso meio


Assuntos
Humanos , Masculino , Lactente , Morte Súbita , Morte Súbita do Lactente , Aminofilina/uso terapêutico
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