Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Res Vet Sci ; 84(3): 471-6, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17709123

RESUMO

The effects of mycotoxin zearalenone and their major metabolites alpha- and beta-zearalenol on spontaneous contractions in isolated lamb uterine smooth muscle were examined. The study was carried out on 20 female prepubertal lambs aged between 45 and 50 days. Myometrial strips were set up in two isolated organ baths (10ml) at 37 degrees C and were exposed to increasing concentrations (10(-11)M-10(-6)M) of these mycoestrogens and results were compared with the effect, at the same concentrations, of natural estrogen 17beta-estradiol. Our findings suggest that mycotoxins and 17beta-estradiol, at nanomolar concentrations, rapidly enhance phasic spontaneous smooth muscle contraction. In particular, zearalenone increases the uterine activity similarly to 17beta-estradiol. On the contrary, its metabolite alpha-zearalenol significantly inhibits myometrial contractility.


Assuntos
Contração Muscular/fisiologia , Micotoxinas/toxicidade , Miométrio/fisiologia , Animais , Peso Corporal , Feminino , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Miométrio/efeitos dos fármacos , Maturidade Sexual , Ovinos , Útero/efeitos dos fármacos , Útero/fisiologia
2.
Chemosphere ; 66(10): 1904-10, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16962639

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in bivalves (Mitylus galloprovincialis), cephalopods (Todarodes sagittatus), crustaceans (Nephrops norvegicus) and fish (Mullus barbatus, Scomber scombrus, Micromesistius poutassou, Merluccius merluccius) in several pools coming from the Central Adriatic Sea. These marine organisms were selected because of their multitude, wide distribution and common use in the Italian diet, they were sampled and analyzed during the year 2004. Acenaphthene, benzo(a)pyrene, dibenz(a,h)anthracene, benzo(ghi)perylene and indeno(1,2,3-cd)pyrene showed levels below the instrumental detection limit in all samples. Fluorene, phenanthrene, anthracene, fluoranthene, benz(a)anthracene, benzo(b)fluoranthene and benzo(k)fluoranthene were detected at different concentrations in analyzed samples. Chrysene was detected only in mussels with very low values (average 0.74ngg(-1) wet weight). PAHs composition pattern was dominated by the presence of PAHs with 3-rings (62%) followed from those with 4-rings (37%) and 5-rings (1%). Atlantic mackerel, European hake and blue whiting showed the highest PAH concentrations, ranging from 44.1 to 63.3ngg(-1) wet weight, the group of invertebrate organisms showed a level of contamination about three times lower than those of the vertebrate groups. Mediterranean mussels that did not present very high levels of contamination expressed as sum of PAHs showed one of the highest values of benzo(a)pyrene equivalents (BaPEs). Conversely the latter value was very low in Atlantic mackerel even if this species reported the highest total PAH concentrations. No significant correlation was observed between weight, length and trophic levels and total PAHs.


Assuntos
Bivalves/metabolismo , Cefalópodes/metabolismo , Crustáceos/metabolismo , Peixes/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Animais , Itália , Hidrocarbonetos Policíclicos Aromáticos/química , Água do Mar/análise , Poluentes Químicos da Água/química
3.
Dis Aquat Organ ; 71(2): 155-61, 2006 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-16956063

RESUMO

We detected concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) in the liver, muscle, and fat of 11 loggerhead sea turtles Caretta caretta from the central and southern Adriatic Sea. All samples contained PCBs at various concentrations, with Congener 138 (28%), 153 (27%), and 180 (32%) dominating the congener composition of the tissues. The dioxin-like congener (118, 13%) was detected in all tissues analyzed. The lower-chlorinated PCBs were not detected. The average of the total PCB concentrations, expressed in nanograms per gram wet weight, was 459.6 ng g(-1) in fat, 82.9 ng g(-1) in liver, and 5.8 ng g(-1) in muscle. Among 13 organochlorine pesticides for which analyses were conducted, 4 were detected: p,p'-DDE (57%); p,p'-DDD (16%); and p,p'-DDT and o,p'-DDT (27%). Spatial differences were found among OC concentrations in loggerheads from the central and southern Adriatic Sea. The only samples containing detectable concentrations of p,p'-DDT and o,p'-DDT were from the southern area.


Assuntos
Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Tartarugas/metabolismo , Poluentes Químicos da Água/análise , Tecido Adiposo/química , Animais , Exposição Ambiental , Fígado/química , Músculo Esquelético/química
4.
Chemosphere ; 57(5): 391-400, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15331266

RESUMO

Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were found in tissue of marine organisms such as Mediterranean mussel, Norway lobster, red mullet, common cuttle-fish, European flying squid, European anchovy, European pilchard and Atlantic mackerel, coming from two sites along the Abruzzo coast of the Adriatic Sea. Species were selected due to their habitat, trophic level, feeding behaviour and their use in the Italian diet. Mussels, filter feeder and sedentary organisms, were used in order to test water pollution whereas Norway lobster and red mullet (benthic fish) were used in order to test sediment pollution. The concentration of ?PCBs exceeded that of ?OCs in the samples analysed. The highest concentrations of ?PCBs (1415 ng/g lipid weight) and ?OCs (507 ng/g lipid weight) were found in pilchard while the lowest concentrations of the same pollutants were found in cephalopods. Our results have shown that species such as anchovy, pilchard and mackerel, were the most polluted due to their location at the last level of the trophic chain. All samples contained different concentrations of PCBs and among these, congeners 153 and 138 were the most representative. Among the OCs, except for the cuttle-fish, the highest concentrations were found for p,p(')-DDE and p,p(')-DDD that are metabolite of DDT. The prevailing DDE presence, compared to DDT (high DDE/DDT ratio), suggested that the biotransformation rate of pollutants was very efficacious in fish and above all in crustaceans. Results have also been interpreted in terms of geographical distribution and organisms' biological cycle. None of the samples analysed exceeded the tolerance limits established by the OCs Italian legislation.


Assuntos
Monitoramento Ambiental/estatística & dados numéricos , Poluentes Ambientais/metabolismo , Peixes/metabolismo , Hidrocarbonetos Clorados/metabolismo , Invertebrados/metabolismo , Bifenilos Policlorados/metabolismo , Análise de Variância , Animais , Cadeia Alimentar , Cromatografia Gasosa-Espectrometria de Massas , Geografia , Sedimentos Geológicos/análise , Mar Mediterrâneo , Água do Mar/análise
5.
Eur J Radiol ; 79(1): 21-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20007012

RESUMO

PURPOSE: To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS: In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS: Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION: In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.


Assuntos
Angiografia/métodos , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Endovasculares/métodos , Tomografia Computadorizada por Raios X , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Humanos , Iopamidol/análogos & derivados , Masculino , Estudos Prospectivos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador
6.
J Exp Zool A Ecol Genet Physiol ; 315(8): 447-57, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21678562

RESUMO

Rainbow trout (Oncorhynchus mykiss) intestinal strips (n = 10) were mounted in an isolated organ bath and the effect of incremental doses of compound 48/80 was recorded. Compound 48/80 induced concentration-related contraction in all the examined strips following a sigmoidal dose-response curve fit. Values for maximal contraction (E(max) , g cm(-2)), negative logarithm of the EC(50) (pD(2)), and hill slope were, respectively (mean±standard error), 12.88 ± 0.51, 1.88 ± 0.05, 1.49 ± 0.27. The histological modification induced on mast cells (MCs) due to compound 48/80 was characterized by mean of gray-levels and texture analysis. Significant differences were observed between gray-levels values (Linear mixed model, P<0.01), contrast, and entropy (Linear mixed model, P<0.05) of MCs from compound 48/80-treated strips compared with MCs from untreated strips. Moreover, maximal intestinal contraction (due to compound 48/80) correlates positively and significantly (Pearson and Spearman correlations, P<0.05) with degranulation intensity determined by means of gray-levels analysis. Four antisera were tested on intestinal sections and no MCs positive to serotonin, substance P, met-enkephalin, and bombesin were found. This study demonstrates that compound 48/80 induces the degranulation of trout intestinal MCs ex vivo, and that the aforementioned degranulation promotes a concentration-dependent intestinal contraction.


Assuntos
Degranulação Celular , Mastócitos/fisiologia , Oncorhynchus mykiss/fisiologia , p-Metoxi-N-metilfenetilamina/farmacologia , Animais , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Mastócitos/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA