131 research outputs found
Conclusions of the French Food Safety Agency on the toxicity of bisphenol A
Since more than 10 years, risk assessment of bisphenol A (BPA) is debated at the international level. In 2008, the U.S. National Toxicology Program (NTP) expressed some concern for adverse effects, at current level of exposure to BPA, on developmental toxicity. In this context, the French Food Safety Agency (AFSSA) decided to review the toxicity data on BPA with a special focus on this endpoint at doses below 5mg/kg bw/day (the no observed adverse effect level set by different regulatory bodies). This paper summarizes the conclusions of a collective assessment conducted by an expert Working Group from AFSSA. Studies were classified into 3 groups: (i) finding no toxicity, (ii) reporting results not considered to be of concern and (iii) indicating warning signals. The term "warning signal" means that no formal conclusion can be drawn regarding the establishment of a health based guidance value but the study raises some questions about the toxicity of BPA at low doses. It was concluded that studies are needed to ascertain the significance for human health of these warning signals and to be able to propose new methodologies for assessing the risks associated with low doses of BPA and more generally of endocrine disruptors
Determination of neophytadiene in the subcutaneous fat of Iberian pigs from different feeding systems
This study was carried out in order to determine the relationship between the content of a branched hydrocarbon (neophytadiene) in the subcutaneous fat and the feeding system of Iberian pigs during the fattening period previous to slaughter. Thirty-six batches of Iberian pigs, belonging to the four categories of feeding systems described in the Spanish legislation (<i>Bellota, Recebo, Campo</i> and <i>Cebo</i>) were studied. These categories differ in their degree of utilization of the natural resources (acorn and pasture) of the extensive rearing system or in their level of replacement by concentrated feed. SPE combined with GC-MS techniques were carried out to isolate and to identify hydrocarbons. Recebo and Bellota batches showed the highest levels of neophytadiene content, followed by <i>Campo</i> batches, and finally, batches of the <i>Cebo</i> category. The results showed a great variability between batches from the same feeding category, mainly from <i>Bellota, Recebo</i> and <i>Campo</i> categories, which makes the classification of the animals in these three categories difficult. However, the animals from the Cebo category were correctly classified when reared in intensive conditions.<br><br>El objetivo del trabajo se centrĂł en determinar el contenido de un hidrocarburo ramificado (neofitadieno) en la grasa subcutánea del cerdo ibĂ©rico, y su relaciĂłn con el tipo de alimentaciĂłn recibida durante la etapa de cebo previa al sacrificio (en la fase final de cebo). Para ello, se estudiaron treinta y seis lotes de cerdos IbĂ©ricos, pertenecientes a las cuatro categorĂas de calidad en base a la alimentaciĂłn de los animales establecidas en la Norma de Calidad (<i>Bellota, Recebo, Campo</i> y <i>Cebo</i>). Estas categorĂas se diferencian en el grado de aprovechamiento de los recursos naturales de la dehesa (bellotas y hierba) y en el nivel de sustituciĂłn de los mismos por piensos concentrados. Para el aislamiento e identificaciĂłn de los hidrocarburos se utilizaron tĂ©cnicas de SPE combinadas con GC-MS. Los lotes de Recebo y Bellota presentaron los mayores niveles de neofitadieno, seguidos por los lotes de Campo, y por Ăşltimo los lotes de Cebo. Se observĂł una gran variabilidad en los niveles de neofitadieno entre los lotes pertenecientes a una misma categorĂa de alimentaciĂłn, sobre todo en los lotes de Bellota, Recebo y Campo, por lo que es difĂcil una correcta clasificaciĂłn de los animales en las tres categorĂas en base al contenido en neofitadieno. Sin embargo, la clasificaciĂłn dentro de la categorĂa de cebo se hace de forma correcta cuando los cerdos son producidos en condiciones intensivas
Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows
Background and Objectives Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from patients with myelofibrosis differed from that in samples from controls.Design and Methods We assessed the microvascular density (MVD), vessel morphology and pericyte coverage in bone marrows from 19 myelofibrosis patients and nine controls. We also studied the same parameters in two mouse models of myelofibrosis, with genetic alterations affecting megakaryocyte differentiation (i.e. one model with low GATA-1 expression and the other with over-expression of thrombopoietin).Results In myelofibrotic marrows, MVD was 3.8-fold greater than in controls (
Estimation of grass intake by lambs using n-alkanes as markers
International audienc
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