From the farm to the lab: how chicken embryos contribute to the field of teratology

Funding This study received no specific grant from any funding agency in the public, commercial or not-for402 profit sectors. Acknowlegment We would like to thank all previous researches that established chicken embryos as a really important and respected experimental model to the teratology field through the history. NV lab funded by Royal Society, Wellcome Trust, Sarcoma UK, NIH. LRF lab funded by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) [grant number 424362/2018-0], Fundo de Incentivo a Pesquisa e Eventos (FIPE) of the Hospital de Clínicas de Porto Alegre (HCPA) [grant numbers 2019-0649 and 2017-0342] and PROPESQ/UFRGS through “Recently Hired Professors” [Call 001/2019]. The authors would like to Sophia Martins Simon de Matos for technical assistance on Figure 1 drawing.Peer reviewedPublisher PD

From the farm to the lab : how chicken embryos contribute to the field of teratology

Congenital anomalies and its causes, particularly, by external factors are the aim of the field called teratology. The external factors studied by teratology are known as teratogens and can be biological or environmental factors for example, chemicals, medications, recreational drugs, environmental pollutants, physical agents (e.g., X-rays and maternal hyperthermia) and maternal metabolic conditions. Proving the teratogenicity of a factor is a difficult task requiring epidemiology studies as well as experimental teratology evidence from the use of animal models, one of which is the chicken embryo. This model in particular has the advantage of being able to follow development live and in vivo, with rapid development hatching around 21 days, is cheap and easy to manipulate and to observe development. All this allows the chicken embryo to be used in drug screening studies, teratogenic evaluation and studies of mechanisms of teratogenicity. The chicken embryo shares morphological, biochemical and genetic similarities with humans as well as mammalian species, making them ideal to ascertain the actions of teratogens, as well as screen drugs to test for their safety. Pre-clinical trials for new drugs are carried out in rodents and rabbits, however, chicken embryos have been used to screen new compounds or analogs of thalidomide as well as to investigate how some drugs can lead to congenital malformations. Indeed, the chicken embryo has proved valuable in understanding how many congenital anomalies, seen in humans, arise following teratogen exposure. The aim of this review is to highlight the role of the chicken embryo as an experimental model for studies in teratology, exploring its use in drug screening studies, phenotypic evaluation and studies of teratogenic mechanisms of action. Here, we discuss many known teratogens, that have been evaluated using the chicken embryo model including some medicines, such as, thalidomide, valproic acid; recreational drugs including alcohol; environmental influences, such as viruses, specifically ZIKV, which is a newly discovered human teratogen. In addition, we discuss how the chicken embryo has provided insight on the mechanisms of teratogenesis of many compounds and also how this impact on drug safety

Possibilidade do uso de Mexilhão Dourado contaminado com metais tóxicos em dietas para frangos de corte

Brazilian poultry farming occupies a prominent position in the world scenario and there is a need for this production to occur in a sustainable way, so the nutrition of these animals must be carried out in a way that causes the least possible environmental impact. In front of it, the calcareous shells of the golden mussel, an invading mollusk that occupies a large part of the freshwater rivers of South America, arise and are responsible for generating large environmental impacts. The high content of calcium present in the golden mussel makes it a potential food with the capacity to replace calcitic limestone in broiler diets, but its feeding habit makes it possible to contain contents of toxic metals such as cadmium (Cd) and lead (Pb) that are contained inside the mussel can cause contamination of the chickens and consequently of the food products derived from them.A avicultura brasileira ocupa posição de destaque no cenário mundial e existe a necessidade de que esta produção ocorra de forma sustentável, sendo assim a nutrição destes animais deve ser realizada de forma que provoque o menor impacto ambiental possível. Frente ao exposto surgem as conchas calcárias do mexilhão dourado que é um molusco invasor que ocupa grande parte dos rios de água doce da América do Sul e é responsável por gerar grandes impactos ambientais. O alto teor de cálcio (Ca) presente no mexilhão dourado faz com que este seja um potencial alimento com capacidade de substituir o calcário calcítico em dietas de frangos de corte, porém o seu hábito alimentar filtrador faz com que este possa conter teores de metais tóxicos como o cádmio (Cd) e o chumbo (Pb) que se contidos no interior do mexilhão podem causar contaminação dos frangos e conseqüentemente também dos produtos alimentícios derivados destes

Molecular mechanisms of Zika virus teratogenesis from animal studies : a systematic review protocol

Background: Due to the diversity of studies in animal models reporting that molecular mechanisms are involved in the teratogenic effect of the Zika virus (ZIKV), the objective of the present study is to evaluate the methodological quality of these studies, as well as to demonstrate which genes and which molecular pathways are affected by ZIKV in different animal models. Methods: This search will be performed in four databases: PubMed/MEDLINE, EMBASE, Web of Science, and Scopus, as well as in the grey literature. The studies selection process will be reported through the PRISMA Statement diagram model. All studies describing the molecular mechanisms possibly involved in the development of malformations caused by embryonic/fetal ZIKV exposure in animal models with an appropriate control group and methodology will be included (including, for instance, randomized and non-randomized studies). All animals used as experimental models for ZIKV teratogenesis may be included as long as exposure to the virus occurred during the embryonic/fetal period. From the selected studies, data will be extracted using a previously prepared standard form. Bias risk evaluation will be conducted following the SYRCLE’s Risk of Bias tool. All data obtained will be tabulated and organized by outcomes (morphological and molecular). Discussion: With the proposed systematic review, we expect to present results about the methodological quality of the published studies with animal models that investigated the molecular mechanisms involved in the teratogenic effect of ZIKV, as well as to show the studies with greater reliability

Avaliação do uso de diferentes fontes e doses de zinco sobre a produção e fitodisponibilidade de metais no capim tânzania

O zinco (Zn) é um micronutriente essencial para as plantas, sendo a autilização da fertilização de forrageiras com este elemento importante, pois grande parte dos solos no Brasil possuem concentrações deficientes deste micronutriente. O presente trabalho teve por objetivo avaliar a produção de matéria seca do capim tanzânia (Panicum maximum Jacq. cv. Tanzânia) e a disponibilização de Zn e dos metais pesados cádmio (Cd), chumbo (Pb) e cromo (Cr) no solo e no tecido vegetal de plantas fertilizadas com diferentes fontes (A, B, C, D e E) e doses de Zn (0, 2, 4, 6 kg ha-1). O experimento foi realizado em casa de vegetação no município de Marechal Cândido Rondon-PR utilizando-se um Latossolo Vermelho eutrófico (LVe), de textura média.  Observou-se que em relação à produtividade não houve diferença significativa, já em relação ao Zn contido na folha, podemos observar que a fonte A se diferenciou das demais, disponibilizando maior quantidade do micronutriente para o tecido vegetal. As fontes de Zn proporcionaram aumento do elemento tóxico Pb no solo do experimento e a fonte A proporcionou aumento na concentração deste elemento no tecido foliar. Fatos estes que devem ser levados em conta, pois fertilizações sucessivas podem aumentar as concentrações destes elementos nocivos no meio ambiente.

The effect of exogenous enzymes on the performance and digestibility of nutrients in broiler

Here we tested how feeding with exogenous enzymes affects the performance, carcass yield, and ileal digestibility in broilers from 21- to 42-days-old. The study included 1008 male broilers randomly distributed into six diets: positive control (PC), corn and soybean meal containing all the nutritional requirements; negative control (NC), with a 120 kcal.kg-1 reduction in metabolizable energy relative to the PC; enzyme complex one (NC + 100 ppm of endo-1,4-beta-xylanase); enzyme complex two (NC + 200 ppm of xylanase, amylase and protease); enzyme blend one (NC + 100 FXU kg-1 of xylanase and 200 FXU kg-1 of amylase); and enzyme blend two (NC + 100 FXU kg-1 of xylanase and 300 FXU kg-1 of amylase). The enzyme complex two (CN + 100 FXU.kg de xilanase e 300 FXU.kg de amilase) and enzyme blend two (NC + 100 FXU kg-1 of xylanase and 300 FXU kg-1 of amylase) had greater weight gain, feed conversion, carcass yield, and digestibility of nutrients than the NC (P < 0,05). We found that enzyme complex two and enzyme blend two valued their nutritional matrix promoting better performance and digestibility of broilers

Fitodisponibilidade de metais e produção de tifton 85 cultivada com diferentes fontes e doses de zinco

The element zinc (Zn) is considered an essential micronutrient to plants, being that the addition of this metal in forage cultivation may cause increment in the productivity. In Brazilian soils are frequent the cases of Zn deficiency, being necessary the fertilization of these areas with this micronutrient. However it must be highlighted that some sources of this micronutrient available in the market present in its composition heavy metals. This work aimed to study the effect of different sources and doses of Zn applied in Tifton 85 and the production of dry matter and the levels of Zn, phosphorus (P), cadmium (Cd), lead (Pb) and chromium (Cr) in leaf tissue and the levels Zn, Cd, Pb and Cr in soil. The experiment was conducted in a greenhouse using a Rhodic oxisol of medium texture. Vases with volume of 4 dm3 were used, which were organized in a completely randomized in factorial scheme (5x4) with three replications. The treatments were the five sources of Zn (A, B, C, D) in four doses of the micronutrient (0, 2, 4, 6 kg ha-1). The results show that did not occurred accumulation of Cd, Pb and Cr in the leaf tissue and Cd and Cr in the soil. The source E provided higher production of dry matter in relation to the sources A, B, C, D. However the source &#39;A&#39; provided higher concentrations of Zn for the forage.O elemento zinco (Zn) &eacute; um micronutriente essencial &agrave;s plantas, sendo que a adi&ccedil;&atilde;o deste em cultivos pode gerar incremento de produtividade. Em solos brasileiros s&atilde;o frequentes os casos de defici&ecirc;ncia de Zn, o que torna necess&aacute;ria a fertiliza&ccedil;&atilde;o destas &aacute;reas com este nutriente. Por&eacute;m deve-se destacar que algumas fontes deste micronutriente dispon&iacute;veis no mercado apresentam em sua composi&ccedil;&atilde;o metais pesados. Este trabalho objetivou estudar o efeito de diferentes fontes e doses de Zn aplicadas na tifton 85 sobre a produ&ccedil;&atilde;o de mat&eacute;ria seca e teores de Zn, f&oacute;sforo (P), c&aacute;dmio (Cd), chumbo (Pb) e cromo (Cr) no tecido vegetal e teores de Zn, Cd, Pb e Cr no solo. O experimento foi conduzido em ambiente protegido utilizando-se um Latossolo Vermelho eutr&oacute;fico (LVe) de textura m&eacute;dia. Foram utilizados vasos com o volume de 4 dm3, organizados em delineamento inteiramente casualizado (DIC), sob esquema fatorial (5x4) e tr&ecirc;s repeti&ccedil;&otilde;es. Os tratamentos foram compostos por cinco fontes de Zn (A, B, C, D, E) e quatro doses do nutriente (0, 2, 4, 6 kg ha-1). Os resultados mostram que n&atilde;o ocorreu ac&uacute;mulo de Cd, Pb e Cr no tecido foliar e de Cd e Cr no solo. Entre as fontes estudadas, a fonte E gerou maior produ&ccedil;&atilde;o de mat&eacute;ria seca em rela&ccedil;&atilde;o as fontes A, B, C, D. J&aacute; a fonte A disponibilizou as maiores concentra&ccedil;&otilde;es de Zn para a forrageira