Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Arch Environ Contam Toxicol ; 75(4): 594-606, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30116839

RESUMO

Wildlife species, such as roe deer, moose, brown hare, wild boar, etc., are known to accumulate persistent environmental contaminants and thus are useful as bioindicators for environmental pollution. Wild boars become exposed to perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from flora, fauna, water, and soil. The main exposure pathway to PFOA and PFOS is assumed to be the oral intake. From studies in domestic pigs (belonging to the same species Sus scrofa), it has been established that the oral exposure results in the liver accumulation of PFOA and PFOS. Thus, we posit that wild boars can be quantitatively used as suitable bioindicators for the presence of these substances in the environment. After the environmental pollution case in the Hessian region Sauerland in 2006, monitoring programs of individual Federal States from 2007 to 2013 showed that almost all wild boar liver samples contained PFOA and PFOS. In 2014, the analyses of PFOA and PFOS in liver of wild boars hunted in the south, north, and west of Germany showed liver concentrations at the same level among regions. Overall, an average ratio of PFOS:PFOA concentration in liver of 20.5:1 was found. To estimate the actual ratio of PFOS:PFOA in the wild boars' dietary exposure, we performed toxicokinetic modeling. According to the model, the PFOS exposure is only 2.2 times that of PFOA (because PFOS has slower elimination kinetics and higher affinity for the liver than PFOA). Overall, the determination of PFOA and PFOS in liver of wild boars indicates that both substances are ubiquitously distributed in the environment. At the same time, higher exposures were found for animals living in closer proximity to dense human populations.


Assuntos
Ácidos Alcanossulfônicos/análise , Caprilatos/análise , Exposição Ambiental/análise , Poluição Ambiental/análise , Fluorocarbonos/análise , Sus scrofa , Ácidos Alcanossulfônicos/farmacocinética , Animais , Caprilatos/farmacocinética , Exposição Dietética/análise , Biomarcadores Ambientais , Monitoramento Ambiental/métodos , Feminino , Fluorocarbonos/farmacocinética , Alemanha , Fígado/química , Fígado/efeitos dos fármacos , Masculino
2.
J Appl Microbiol ; 121(3): 644-56, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27230806

RESUMO

AIMS: This study was performed in a well-established in vitro model to investigate whether the application of a glyphosate-containing herbicide might affect the bacterial communities and some biochemical parameters in a cow's rumen. METHODS AND RESULTS: The test item was applied in two concentrations (high and low) for 5 days. In a second trial, fermentation vessels were inoculated with Clostridium sporogenes before the high dose was applied. Effluents were analysed by biochemical, microbiological and genetic methods. A marginal increase in short-chain fatty acid production and a reduction in NH3 -N were observed. There were minor and rather equivocal changes in the composition of ruminal bacteria but no indications of a shift towards a more frequent abundance of pathogenic Clostridia species. Clostridium sporogenes counts declined consistently. CONCLUSIONS: No adverse effects of the herbicide on ruminal metabolism or composition of the bacterial communities could be detected. In particular, there was no evidence of a suspected stimulation of Clostridia growth. SIGNIFICANCE AND IMPACT OF THE STUDY: Antibiotic activity of glyphosate resulting in microbial imbalances has been postulated. In this exploratory study, however, intraruminal application of concentrations reflecting potential exposure of dairy cows or beef cattle did not exhibit significant effects on bacterial communities in a complex in vitro system. The low number of replicates (n = 3/dose) may leave some uncertainty.


Assuntos
Bactérias/classificação , Bovinos/metabolismo , Clostridium/crescimento & desenvolvimento , Microbioma Gastrointestinal/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Rúmen/metabolismo , Animais , Bactérias/metabolismo , Bovinos/microbiologia , Clostridium/classificação , Clostridium/efeitos dos fármacos , Dieta , Ácidos Graxos/análise , Feminino , Fermentação , Suco Gástrico/microbiologia , Glicina/toxicidade , Técnicas In Vitro , Rúmen/microbiologia , Glifosato
3.
J Dairy Sci ; 99(7): 5318-5324, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27108173

RESUMO

From 6 balance experiments with total collection of feces and urine, samples were obtained to investigate the excretion pathways of glyphosate (GLY) in lactating dairy cows. Each experiment lasted for 26d. The first 21d served for adaptation to the diet, and during the remaining 5d collection of total feces and urine was conducted. Dry matter intake and milk yield were recorded daily and milk and feed samples were taken during the sampling periods. In 2 of the 6 experiments, at the sampling period for feces and urine, duodenal contents were collected for 5d. Cows were equipped with cannulas at the dorsal sac of the rumen and the proximal duodenum. Duodenal contents were collected every 2h over 5 consecutive days. The daily duodenal dry matter flow was measured by using chromium oxide as a volume marker. All samples (feed, feces, urine, milk and duodenal contents were analyzed for GLY and aminomethylphosphonic acid (AMPA). Overall, across the 6 experiments (n=32) the range of GLY intake was 0.08 to 6.67mg/d. The main proportion (61±11%; ±SD) of consumed GLY was excreted with feces; whereas excretion by urine was 8±3% of GLY intake. Elimination via milk was negligible. The GLY concentrations above the limit of quantification were not detected in any of the milk samples. A potential ruminal degradation of GLY to AMPA was derived from daily duodenal GLY flow. The apparent ruminal disappearance of GLY intake was 36 and 6%. In conclusion, the results of the present study indicate that the gastrointestinal absorption of GLY is of minor importance and fecal excretion represents the major excretion pathway. A degradation of GLY to AMPA by rumen microbes or a possible retention in the body has to be taken into account.


Assuntos
Lactação , Rúmen/metabolismo , Ração Animal , Animais , Bovinos , Dieta/veterinária , Digestão , Feminino , Leite
4.
Toxicol Lett ; 314: 82-88, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306742

RESUMO

For decades, phthalates have been widely used as plasticizers in a large number of consumer products, leading to a complex exposure to humans via ingestion, inhalation or dermal uptake. Children may have a higher unintended dust intake per day compared to adults. Therefore, dust intake of children could pose a relevant exposure and subsequently a potential health risk. The aim of this study was to determine the relative bioavailability of certain phthalates, such as di(2-ethylhexyl) phthalate (DEHP), di-isononyl phthalate (DINP) and the non-phthalate plasticizer diisononyl 1,2-cyclohexanedicarboxylic acid (DINCH®, Hexamoll®), after ingestion of dust. Seven 5-week-old male piglets were fed five different dust samples collected from daycare centers. Overall, 0.43 g to 0.83 g of dust sieved to 63 µm were administered orally. The piglets' urine was collected over a period of 38 h. The excreted metabolites were quantified using an LC-MS/MS method. The mean uptake rates of the applied doses for DEHP, DINP, and DINCH® were 43% ± 11%, 47% ± 26%, and 9% ± 3.5%, respectively. The metabolites of DEHP and DINP showed maximum concentrations in urine after three to five hours, whereas the metabolites of DINCH®, reached maximum concentrations 24 h post-dose. The oral bioavailability of the investigated plasticizers was higher compared to the bioaccessibility reported from in vitro digestion tests. Furthermore, the bioavailability of DEHP did not vary substantially between the dust samples, whereas a dose-dependent saturation process for DINP was observed. In addition to other intake pathways, dust could be a source of plasticizers in children using the recent intake rates for dust ingestion.


Assuntos
Ácidos Cicloexanocarboxílicos/administração & dosagem , Ácidos Dicarboxílicos/administração & dosagem , Poeira , Ácidos Ftálicos/administração & dosagem , Plastificantes/administração & dosagem , Administração Oral , Fatores Etários , Animais , Animais Recém-Nascidos , Disponibilidade Biológica , Cromatografia Líquida , Ácidos Cicloexanocarboxílicos/farmacocinética , Ácidos Cicloexanocarboxílicos/toxicidade , Ácidos Cicloexanocarboxílicos/urina , Ácidos Dicarboxílicos/farmacocinética , Ácidos Dicarboxílicos/toxicidade , Ácidos Dicarboxílicos/urina , Masculino , Ácidos Ftálicos/farmacocinética , Ácidos Ftálicos/toxicidade , Ácidos Ftálicos/urina , Plastificantes/farmacocinética , Plastificantes/toxicidade , Medição de Risco , Sus scrofa , Espectrometria de Massas em Tandem , Toxicocinética , Urinálise
5.
Environ Sci Eur ; 27(1): 30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27752431

RESUMO

BACKGROUND: The behaviour of perfluoroalkyl acids (PFAAs) in tissues of ruminants has been shown to differ from that of monogastrics (J Agric Food Chem 61(12):2903-2912 doi:10.1021/jf304680j, 2013; J Agric Food Chem 62(28):6861-6870, 2014). This may be a consequence of the complex microbial ecosystem in the rumen. To evaluate this hypothesis, the recovery of PFAAs was studied using the rumen simulation technique as an indication for biodegradation in rumen. The PFAA-recovery from a microbial fermentation of feed containing PFAAs was compared to the same feed in the absence of ruminal microorganisms (MOs). RESULTS: Release of PFAAs from feed into fermentation fluid was found to be faster for perfluorobutane sulfonic acid (PFBS) than for perfluorooctane sulfonic acid (PFOS). Differences between perfluoroalkyl carboxylic acids (PFCAs) could not be observed. Proportions of PFAAs recovered in the fermentation fluids decreased by increasing chain lengths for the perfluoroalkyl sulfonic acids (PFSAs) (31 % PFBS, 28 % perfluorohexane sulfonic acid [PFHxS], 20 % perfluoroheptane sulfonic acid [PFHpS], 11 % PFOS) and PFCAs (33 % perfluorohexane carboxylic acid [PFHxA], 32 % perfluoroheptane carboxylic acid [PFHpA], 24 % perfluorooctanoic acid [PFOA]). In contrast, levels in feed increased with increasing chain length for both PFSAs and PFCAs. CONCLUSION: The attachment of MOs to feed particles was assumed to account for higher PFAA levels in fermented feeds and for lower levels in the fermentation fluids. Total recovery of PFAAs was significantly lower in presence of ruminal MOs compared to experimental procedure under sterile conditions. Although, there are optimal reductive conditions for MOs in rumen, our results do not univocally indicate whether PFAAs were degraded by ruminal fermentation.

6.
Anim Health Res Rev ; 10(1): 21-34, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19195425

RESUMO

Mastitis is not only a major cause of economic losses to the dairy industry but also a major problem in ensuring the quality and safety of the milk, associated with high somatic cell counts and residues of antibiotics used for treatment. One innovative approach to protection against mastitis is to stimulate the animal's natural defense mechanisms. Technological advances in immunological research have increased our ability to exploit the immunity of the bovine mammary gland during periods of high susceptibility to disease. The trace element selenium affects the innate and the adaptive immune responses of the mammary gland through cellular and humoral activities. Substantial research has been carried out on the effect of selenium (Se) on the immune function of the mammary gland and subsequent improvement in bovine udder health and mastitis control. Levels higher than current recommendations and Se-yeast can potentially be used to enhance our capacity to modulate the physiological mechanisms of the bovine mammary gland to respond to infection. This article provides an overview of the most recent research in this field.


Assuntos
Suscetibilidade a Doenças/veterinária , Glândulas Mamárias Animais/imunologia , Mastite Bovina/imunologia , Mastite Bovina/prevenção & controle , Selênio/farmacologia , Animais , Formação de Anticorpos , Bovinos/imunologia , Suplementos Nutricionais , Suscetibilidade a Doenças/imunologia , Feminino , Imunidade Celular , Imunidade Inata , Leite/citologia , Leite/imunologia , Leite/microbiologia , Selênio/administração & dosagem
7.
Z Kardiol ; 70(3): 191-7, 1981 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-7234049

RESUMO

The natural history of chronic aortic valve disease is well known from non-invasive data, but invasive data documenting the natural course of this disease are lacking. We studied hemodynamic data of 45 patients who had chronic aortic valve disease and were in functional class III or IV. All patients were candidates for prosthetic aortic valve replacement, but refused operation. These patients document the natural course of aortic valve disease. Invasive hemodynamic data were obtained by heart catheterization. Patients with aortic stenosis who died during the observation period had a transvalve gradient of 83 +/- 40 mm Hg, which was comparable to the gradient of survivors (70 +/- 16 mm Hg, p greater than 0.05), but left ventricular end-diastolic pressure, mean left atrial pressure and pulmonary artery pressure were higher indicating impaired left ventricular function. Patients with aortic stenosis who were repeatedly studied with heart catheterization (n = 7, average interval between studies 3.3 years) showed a significant increase of left ventricular filling pressure and of pulmonary arteriolar resistance and a fall of cardiac index. Patients with aortic insufficiency who died during the observation period had higher left ventricular filling pressures than survivors. Patients with aortic insufficiency who were repeatedly studied with heart catheterization (n = 5, average interval 2.9 years) showed no change of hemodynamic parameters. The latter group showed symptomatic deterioration although hemodynamics were unchanged. We conclude, in chronic aortic valve disease hemodynamic parameters regarding left ventricular function have prognostic implications.


Assuntos
Insuficiência da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/diagnóstico , Hemodinâmica , Adulto , Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Fibrilação Atrial/diagnóstico , Morte Súbita/etiologia , Feminino , Insuficiência Cardíaca/diagnóstico , Próteses Valvulares Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA