No description available.

The objective of this study was to evaluate the effects of orally administered soy-derived extracts on normal reproductive development in neonatal pigs as a model for infants on soy formula. Yorkshire-Landrace crossbred sows were randomly assigned to a lactating diet supplemented with either Novasoy 70 or without. Feed was top-dressed from d 100 of gestation until farrowing. Neonatal pigs (NPs) were weighed on post natal day (PND) six then randomly assigned to one of four treatments 1) control, 2) estradiol, 3) low, or 4) high genistein dose. This study demonstrates that oral exposure of NPs to estradiol but not genistein alters reproductive tract development and that this effect may be amplified from in utero exposure to sow diets with elevated concentrations of phytoestrogens. Thus, the neonatal pig may provide a useful model for assessing effects of dietary phytoestrogens on reproductive development in infants on soy-based formulas.

No description available.

<p>This thesis examined neurotoxic effects of nicotine exposure during a defined critical period of neonatal brain development in mice.</p><p>In our environment there are numerous hazardous contaminants that an individual can be exposed to during its entire lifetime. In many mammalian species the neonatal period is characterised by a rapid development of the brain. The present studies have identified a defined critical period during the neonatal brain development in mice, where exposure to low doses of nicotine causes permanent disturbances in the cholinergic nicotinic receptors and altered behaviour response to nicotine at adult age. This adult reaction to nicotine, a hypoactive response, was the opposite of that observed in control animals and animals exposed to nicotine before or after this period. Animals showing a hypoactive response to nicotine lacked nicotinic low affinity binding sites in the cerebral cortex. Furthermore, neonatal exposure to nicotine affected learning and memory in adult animals, an effect that was time-dependent. This thesis also showed that neonatal exposure to nicotine increased adult susceptibility to a repeated exposure of nicotine, manifested as an even more pronounced effect in spontaneous behaviour after challenging doses of nicotine. In these animals the nicotinic receptors in the cerebral cortex, assayed by a-bungarotoxin, was decreased. </p><p>Neonatal exposure to nicotine was also shown to increase adult susceptibility to the organophosphate paraoxon, a known cholinergic agent, and to the brominated flame retardant 2,2´,4,4´,5-pentabromodiphenyl ether, a novel environmental agent, at adult age. This was seen at doses that did not affect behaviour in control animals, and was manifested as deranged spontaneous behaviour and reduced habituation, aberrations that also worsened with age. </p><p>The results indicate that differences in adult susceptibility to environmental pollutants are not necessarily an inherited condition. Rather they may well be acquired by low dose exposure to toxic agents during early life.</p>

This thesis examined neurotoxic effects of nicotine exposure during a defined critical period of neonatal brain development in mice. In our environment there are numerous hazardous contaminants that an individual can be exposed to during its entire lifetime. In many mammalian species the neonatal period is characterised by a rapid development of the brain. The present studies have identified a defined critical period during the neonatal brain development in mice, where exposure to low doses of nicotine causes permanent disturbances in the cholinergic nicotinic receptors and altered behaviour response to nicotine at adult age. This adult reaction to nicotine, a hypoactive response, was the opposite of that observed in control animals and animals exposed to nicotine before or after this period. Animals showing a hypoactive response to nicotine lacked nicotinic low affinity binding sites in the cerebral cortex. Furthermore, neonatal exposure to nicotine affected learning and memory in adult animals, an effect that was time-dependent. This thesis also showed that neonatal exposure to nicotine increased adult susceptibility to a repeated exposure of nicotine, manifested as an even more pronounced effect in spontaneous behaviour after challenging doses of nicotine. In these animals the nicotinic receptors in the cerebral cortex, assayed by a-bungarotoxin, was decreased. Neonatal exposure to nicotine was also shown to increase adult susceptibility to the organophosphate paraoxon, a known cholinergic agent, and to the brominated flame retardant 2,2´,4,4´,5-pentabromodiphenyl ether, a novel environmental agent, at adult age. This was seen at doses that did not affect behaviour in control animals, and was manifested as deranged spontaneous behaviour and reduced habituation, aberrations that also worsened with age. The results indicate that differences in adult susceptibility to environmental pollutants are not necessarily an inherited condition. Rather they may well be acquired by low dose exposure to toxic agents during early life.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-22T12:19:47Z No. of bitstreams: 1 lorenaribeirosilva.pdf: 2123336 bytes, checksum: ab76b81e5560787df306ad092e2aa1de (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-22T17:25:27Z (GMT) No. of bitstreams: 1 lorenaribeirosilva.pdf: 2123336 bytes, checksum: ab76b81e5560787df306ad092e2aa1de (MD5) / Made available in DSpace on 2017-05-22T17:25:27Z (GMT). No. of bitstreams: 1 lorenaribeirosilva.pdf: 2123336 bytes, checksum: ab76b81e5560787df306ad092e2aa1de (MD5) Previous issue date: 2015-03-13 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A depressão é uma das desordens psíquicas mais comuns distribuídas na população e que pode acometer mulheres durante o período gestacional. O extrato de Hypericum perforatum L. (Hp) tem sido utilizado para o tratamento de depressão leve a moderada e com menos efeitos adversos do que os antidepressivos alopáticos. Há poucos estudos sobre o seu uso seguro durante a gravidez e de sua interferência na geração exposta durante a vida intrauterina. Portanto, o presente trabalho propôs-se a estudar o efeito da exposição do extrato seco de Hp no desenvolvimento neonatal e no processo de aprendizagem e memória dos filhotes de ratas Wistar tratadas durante a gestação. Foram utilizados ratos Wistar (machos e fêmeas), obtidos da colônia do biotério do Centro de Biologia da Reprodução (CBR) - Universidade Federal de Juiz de Fora (UFJF). Ratas Wistar prenhes foram distribuídas aleatoriamente em quatro grupos (n=10): um controle, que recebeu água filtrada, e três grupos tratados que receberam o extrato de Hp nas doses de 36 mg/kg/dia; 72 mg/kg/dia e 144 mg/kg/dia, durante toda a gestação, por via intragástrica. Após o parto, foram selecionados, aleatoriamente, 10 filhotes fêmeas e 10 filhotes machos de cada grupo experimental. Estes filhotes foram acompanhados no período neonatal para avaliação do desenvolvimento físico e reflexológico e na vida adulta, foram submetidos à avaliação do aprendizado e memória. Para avaliação do desenvolvimento neonatal foram observados os seguintes parâmetros: abertura dos olhos, desdobramento da orelha, aparecimento de lanugo e pelos, erupção do incisivo superior e inferior, abertura vaginal; descida dos testículos; resposta postural, preensão palmar, esquiva ao abismo, teste de orientação e geotaxia negativa. Para avaliação da memória foram utilizados o teste de esquiva inibitória e o teste de reconhecimento de objetos. O projeto foi aprovado pelo protocolo nº 101/2012, CEUA/UFJF. O desenvolvimento físico e reflexológico dos filhotes das ratas dos grupos experimentais ocorreram entre o segundo e o trigésimo sétimo dia de vida pós-natal, não apresentando diferença significativa entre os grupos. Os dados relativos ao aprendizado e memória também não demonstraram alteração significativa. Portanto, o Hp não interferiu no desenvolvimento neonatal e cognitivo em termos de aprendizado e memória dos filhotes das ratas que receberam o extrato durante a gestação. / Depression is one of the most common mental disorders distributed in the population and that can affect women during pregnancy. Hypericum perforatum L. extract (Hp) has been used for the treatment of mild to moderate depression with fewer side effects than allopathic antidepressants. There are few studies on its safe use during pregnancy and its interference in the exposed generation during intrauterine life. Therefore, this study aimed to study the effect of exposure Hp dry extract neonatal development and the process of learning and memory of Wistar rats' pups treated during pregnancy. Wistar rats (male and female), obtained from the animal house of the colony Reproductive Biology Center (CBR) - Federal University of Juiz de Fora (UFJF). Pregnant Wistar rats were randomly distributed into four groups (n = 10) a control, which received filtered water, and three experimental groups that received the Hp extract in doses of 36 mg/ kg/day; 72 mg/kg/day and 144 mg/kg/day throughout gestation, intragastrically. After parturition, were randomly selected 10 young female and 10 male offspring from each experimental group. These puppies were followed in the neonatal period to assess the physical and reflexology and adulthood, underwent assessment of learning and memory. To evaluate the following neonatal development parameters were observed: eye opening, ear splitting, appearance of lanugo and hair, upper and lower incisor eruption, vaginal opening; descent of the testis; postural response, grasping reflex, cliff avoidance, orientation test and negative geotaxis. To assess memory we used the inhibitory avoidance task and the object recognition test. The project was approved by Protocol 101/2012, CEUA / UFJF. The physical and reflexology of the rats in the experimental groups occurred between the second and the thirty-seventh day of postnatal life, with no differences between groups. The data on learning and memory also showed no significant change. Therefore, the Hp did not interfere in the neonatal and cognitive development in terms of learning and memory of the rats receiving the extract during pregnancy.

The American black bear (ABB) (Ursus americanus) exhibits physiological strategies highly synchronized with the environment. Such strategies enable bears to exploit food resources when available and survive the winter months by hibernating without ingesting food or water. However, there are multiple aspects of ABB hibernation physiology that remain unknown. For instance, there is conflicting evidence on the occurrence of ABB pseudopregnancy (a physiological state in which a non-pregnant bear exhibits progesterone levels similar to gravid bears in the absence of an actual pregnancy). Also, there is little known about postnatal development of cubs or the influence of maternal traits on embryonic implantation and cub growth. Finally, the role of satellite cells (SCs – stem cells able to regenerate muscle fibers) play in maintaining muscle functionality during hibernating remains understudied. Therefore, I aimed to assess these four aforementioned aspects using wild ABBs held temporarily captive at Virginia Tech's Black Bear Research Center (VT-BBRC). The major findings of this dissertation are: 1) I suggest that wild ABBs do not experience pseudopregnancy as a reproductive strategy; 2) interactions between litter size and cub age best described postnatal cub weight dynamics and organ development. Twin cubs were heavier than single and triplet cubs, yet cubs from all litter sizes reached similar weights after mothers began consuming food post hibernation. Single cubs experienced delayed timing in ear, eye, and teeth development compared to other litter sizes; 3) maternal traits such as higher body weight and higher ability to gain weight in the fall are closely associated with earlier timing of embryonic implantation than in leaner females, which gained less weight per day in the fall; and 4) SC ability to generate muscle fibers is increased during ABB hibernation. I propose that maintaining the SCs are an important potential pathway for limiting muscle atrophy during bear hibernation. Understanding pre and postnatal development of ABBs is important for exploring factors related to climate, maternal characteristics, which possibly affect birthing phenology, and fitness of bears experiencing rapid anthropogenic environmental change. Functional aspects of bear muscle conservation are interesting for potentially for elucidating avenues to improve treatments for human metabolic disorders such as muscular dystrophy, sarcopenia, and disuse atrophy. / Ph. D.

A naturally occurring disease involving hyperplasia of the thyroid gland and a consistent pattern of musculoskeletal deformities of newborn foals in western Canada was first described in 1981. This disease was an important cause of foal mortality and, therefore, reproductive loss throughout western Canada during the 1990s and has since been recognized in western Ontario and the northwestern United States. A series of investigations were conducted to describe, characterize, and attempt to determine the pathogenesis and cause of this syndrome. Affected foals were typically born after a long gestation (x = 360 days, range = 340 to 400 days), were diagnosed as hypothyroid based on a poor response to the administration of thyroid-stimulating hormone, and had various musculoskeletal lesions of which mandibular prognathism, flexural deformities and rupture of tendons of the limbs, and incomplete ossification of the carpal and tarsal bones were present most commonly. In spite of the normal to long gestation, foals had signs of immaturity, were usually weak and unable to stand, became septic, and died or were euthanatised. Similar histories, clinical findings, and lesions were present in surgically created hypothyroid foals that were thyroidectomized in utero at about 210 days gestation. These findings supported the conclusion that foals which naturally developed these lesions were also hypothyroid in utero and that all the lesions present in affected foals were the result of the hypothyroidism and not of an underlying concurrent disease process. A case-control study was conducted to identify risk factors for naturally occurring congenital hypothyroidism. Information from congenitally hypothyroid foals concerning foal and dam signalment, farm environment, and dam management was compared with that from normal foals. Pregnant mares fed greenfeed, not supplemented with mineral, that left their "home farm" during gestation, or grazed irrigated pasture, had a 13.1 (<i>P</i>=0.0068), 5.6 (<i>P</i>=0.0472), 4.3 (<i>P</i>=0.0076) and approximately 15.3 (<i>P</i>=0.0245) times greater odds, respectively, of producing a congenitally hypothyroid foal than mares not exposed to these factors. Greenfeed often contains high levels of nitrate (NO₃^-) which is known to impair thyroid gland function. In light of this, forage samples from participating farms were analysed for nitrate levels. The odds of one or more congenitally hypothyroid foal being born on a farm feeding forage with at least a trace of nitrate was 8.0 times greater (<i>P</i>=0.0873) than the odds of the disease occurring a farm that fed forage free of nitrate. Further, the odds of a mare producing an affected foal when fed forage containing at least a trace of nitrate was 5.9 times greater (<i>P</i>=0.0007) than a mare fed nitrate-free forage.This study suggests that congenital hypothyroidism in foals may result from diets containing nitrate or low in iodine being fed to pregnant mares. These results need to be confirmed through further field investigations and controlled experiments. However, if they are accurate, there is cause for concern that other livestock raised in areas where congenitally hypothyroid foals occur may be exposed to the same dietary risk factors and may suffer similar disease.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-22T11:31:21Z No. of bitstreams: 1 maraluciadecampos.pdf: 1264653 bytes, checksum: b2a9f890fc102cc866b811fc0c301aae (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T15:28:50Z (GMT) No. of bitstreams: 1 maraluciadecampos.pdf: 1264653 bytes, checksum: b2a9f890fc102cc866b811fc0c301aae (MD5) / Made available in DSpace on 2016-07-13T15:28:50Z (GMT). No. of bitstreams: 1 maraluciadecampos.pdf: 1264653 bytes, checksum: b2a9f890fc102cc866b811fc0c301aae (MD5) Previous issue date: 2012-12-10 / A valeriana é moderadamente sedativa e usada no tratamento da ansiedade e distúrbios do sono. De acordo com a literatura a exposição a psicofármacos que atuam em receptores GABA-A durante a gestação podem provocar alterações comportamentais nos filhotes na vida adulta. O objetivo do presente trabalho foi avaliar o efeito que a administração do extrato de Valeriana durante a gestação possa ter sobre o desenvolvimento físico, o desenvolvimento reflexológico, a ansiedade e a memória dos filhotes. As ratas prenhes foram distribuídas aleatoriamente em quatro grupos (n=10): controle (1ml de água destilada) e três grupos tratados com valeriana, via intragástrica, T-500 (500mg/Kg/dia), T-1000 (1000mg/Kg/dia) e T-2000 (2000mg/Kg/dia) do 12° ao 19° dia de gestação. Depois do nascimento, o comportamento materno foi registrado e os filhotes fêmeas e machos foram avaliados separadamente quanto a alterações no desenvolvimento físico e reflexológico. Os filhotes machos também foram avaliados na vida adulta, 90 dias, quanto à ansiedade e à memória. Os animais apresentaram algumas alterações nas datas de aparecimento dos sinais indicadores físicos, os quais não permaneceram na vida adulta. A data de aparecimento dos reflexos foi semelhante entre os grupos. Em relação à ansiedade e à memória na vida adulta, não houve diferença estatística entre os grupos nos testes utilizados. Portanto, não houve alteração no desenvolvimento neonatal e neurocomportamental dos ratos, não tendo sido possível verificar se tal fato se deveu aos componentes da Valeriana não passarem pela placenta ou se o extrato ser inócuo para os fetos. / Valerian is moderately sedative and used for anxiety problems and sleep disturbance. Previous studies have shown that the exposure to psychopharmacs acting on GABA-A system during gestation in rats can produce behavioral alterations in their descendants in the adult life. This work was designed to evaluate the effects of the exposure to Valeriana officinalis L. (Valerianaceae) during gestation on the physical and reflexological development of the offspring and on their anxiety state and memory in the adult stage. Pregnant rats were randomly distributed into four groups (n = 10): control (1 ml distilled water) and three valerian-treated groups with the doses T-500 (500 mg/Kg/ day), T-1000 (1000 mg/Kg/day) and T-2000 (2000 mg/Kg/ day), administered by gavage, from the 12th to 19th day of gestation. After birth, maternal behavior was evaluated and the physical and reflexological development of the offspring male and females was assessed separately. The anxiety and memory of offspring male were evaluated at 90 days of age. Maternal behavior was not affected by treatment with valerian. The offspring exhibited some alterations on the day of appearance of physical signs, which did not affect the adult life, whereas similar days of appearance of the reflexes were observed among the groups. No significant difference was detected in the offspring in the anxiety and memory tests. Therefore, no alterations in the neonatal and neurobehavioral development of rats exposed to valerian during intrauterine life were found in the present work.