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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

pH intracelular nos neurônios dos gânglios das raízes dorsais. / Intracellular pH in neurons of dorsal root ganglia.

Taniguchi, Érika Yumi 11 May 2017 (has links)
O objetivo do trabalho foi determinar o pHi, a capacidade tamponante do citosol na ausência de CO2/HCO3- (βi) de neurônios dos gânglios das raízes dorsais e investigar a expressão de trocadores Na+/H+ e sua função na regulação do pHi. O pHi foi estimado com o indicador fluorescente BCECF. A operação do trocador era quantificada na recuperação da acidose intracelular induzida experimentalmente. Na ausência do tampão CO2/HCO3- a taxa de alcalinização (k) deve-se, por hipótese, ao transporte de H+ pelo trocador. A hipótese foi confirmada pela ação de agentes farmacológicos, e.g., amiloride. Em soluções tamponadas por CO2/HCO3- as células tem pHi de 7,24 e, em soluções tamponadas com HEPES, 7,04. A βi foi de 8,17 mM/pH. As células se recuperam da acidose com k médio de 0,0138 s-1. O efeito inibitório do amiloride em concentração de 1 mM deve-se ao fato dos fenótipos celulares expressarem diferentes isoformas do trocador. Segundo RT-PCR, todas as 5 isoformas do trocador são expressas e a quantidade de RNAm, avaliada por qPCR, é maior para a NHE1, seguida de NHE5. / The objective here was to determine intracellular pH (pHi), cytosolic buffering power in CO2/HCO3- free medium (βi) of neurons from dorsal root ganglia and to investigate the functional expression of the Na+/H+ exchangers in the regulation of pHi. pHi was estimated with fluorescence indicator BCECF. Exchanger operation was quantified during recovery from intracellular acidification induced experimentally. In CO2/HCO3- free medium the alkalinization rate (k) is due, hypothetically, H+ extrusion by the exchanger. This assumption was confirmed by action of pharmacologic agents, e.g., amiloride. In medium buffered with CO2/HCO3- cells have pHi of 7.24 and, in medium buffered with HEPES, 7.04. βi calculated was 8.17 mM/pH. Cells recovery from acidosis with mean k of 0.0138 s-1. Inhibitory effect of amiloride in 1 mM concentration is due to cellular phenotypes expressing different Na+/H+ exchanger isoforms. According to RT-PCR, all the five exchanger isoforms are expressed and mRNA quantity, evaluated by qPCR, is greater to NHE1, followed by NHE5.
22

O efeito do cimento composto de sulfato de cálcio e beta fosfato tricálcico com controle de potencial zeta sobre o reparo de defeitos ósseos críticos em calvária de ratos / The effect of calcium sulfate and beta-tricalcium phosphate composite with zeta potential control on the healing process of bone critical defects in rats

Daniel Falbo Martins de Souza 02 July 2015 (has links)
Nos defeitos bucomaxilofaciais, a intervenção cirúrgica utilizando enxertos ou substi-tutos ósseos é indicada para reestabelecer a forma e a função perdidas. Nesse con-texto, enxertos auto?genos e alo?genos te?m sido substituídos por biomateriais osteo-condutores e reabsorvíveis. O objetivo deste trabalho foi avaliar por meio de micro-tomografia e dos aspectos histológicos do reparo ósseo, se um novo cimento bifási-co composto por sulfato de cálcio e beta fosfato tricálcico com controle de potencial zeta, poderia induzir ou conduzir a neoformação óssea em defeitos críticos, produzi-dos em calvárias de ratos. Foi realizado um defeito crítico de 8mm de diâmetro na calvária de 40 ratos Wistar machos. No grupo teste (n=20) os defeitos foram preen-chidos pelo cimento. No grupo controle (n=20) os defeitos não foram preenchidos e permaneceram apenas com o coágulo. Os animais sofreram eutanásia em 7, 14, 21 e 42 dias do pós operatório. Espécimes da região da ferida foram microtomografa-dos e posteriormente as amostras foram preparadas para análise histológica. A aná-lise histomorfológica incluiu a avaliação morfológica da histopatologia do reparo, a avaliação morfométrica da área de formação das trabéculas ósseas comparativa-mente entre os grupos. Realizamos ainda a coloração com fosfatase tartrato-resistente (TRAP) para identificação de osteoclastos. Os resultados mostraram que os defeitos preenchidos pelo cimento não apresentaram diminuição significativa da área de acordo com a progressão dos períodos pós-operatórios, pelo contrário, em alguns animais, o defeito aparentemente aumentou. A histomorfologia do reparo mostrou agrupamentos mais expressivos de células gigantes no grupo teste suge-rindo resposta a corpo estranho e osso neoformado mais maduro no grupo controle No grupo teste houve permanência do material e resposta corpo estranho até os úl-timos períodos de observação. Na histomorfometria, a área total de neoformação óssea na região da ferida foi significativamente maior e crescente com o passar do tempo experimental no grupo controle do que no grupo teste. As células gigantes apresentaram expressão histoquímica positiva para TRAP e não foram identificados osteoclastos. Concluímos que neste modelo de estudo, o cimento cerâmico não in-duziu ou conduziu a neoformação óssea de defeitos ósseos críticos criados em cal-vária de ratos sob o ponto de vista microtomográfico e histológico. / Surgical intervention employing grafts and bone substitutes is the best choice in oral and maxillofacial bone defects reconstruction for structural and functional lost. Re-garding this, autogenous and alogenous grafts have been used as osteocondutive and resorbable biomaterials. The aim of this study was to evaluate if a new bone bi-phasic composite of calcium sulfate and beta tricalcium phosphate with zeta potential control could induce or conduct bone formation in rats\' calvarias critical defects mod-el. Forty male Wistar rats underwent 8mm diameter calvaria perforation under gen-eral anesthesia. Animals were randomly allocated to group test (n=20), when the de-fects were filled with the biphasic phosphate and group control (n=20) when the wound was left just with blood clot. Animals underwent euthanasia 7, 14, 21 and 42 days after surgery. Bone calvaria specimens underwent microtomography and histo-logical processing for analysis. Histomorphological and histomorphometry were per-formed regarding aspects of bone healing evolution and new bone total area within the defect. Additionally, histological samples were tartrate-resistant phosphatase (TRAP) stained for osteoclasts identification. The results showed that defects filled by the composite did not present significant bone formation considering postoperative evolution, on the contrary it seemed that the defect area increased in some animals. The bone repair histomorphology in test-group showed expressive giant cells nests involving the ceramic material suggesting foreign body reaction. A mature bone tis-sue neoformation was significantly more intense in the control-group. In the test-group the permanence of the exogenous material caused the sustained foreign body reaction until the last observational periods. Histomorphometric analysis showed that in control-group the total area of bone formation was significantly greater and pro-gressive along the experiment than the test-group. Osteoclasts were not identified but the giant cells presented positive reaction to TRAP. It was possible to conclude that the biphasic ceramic with zeta potential control was not capable to induce or conduct bone neoformation in critical defects created in rats\' calvaria.
23

Translocação bacteriana na isquemia-reperfusão hepática com e sem estase venosa intestinal: estudo experimental em ratos / Bacterial translocation in liver ischemia-reperfusion injury with and without intestinal venous stasis: experimental model in rats

Karin Marie Van Der Heijden 31 August 2007 (has links)
Atualmente, define-se como translocação bacteriana o deslocamento de bactérias e/ou seus produtos, como as endotoxinas, da luz do TGI para sítios estéreis. A ocorrência de translocação bacteriana tem sido sugerida em diversos estudos experimentais e clínicos. Apesar de todos estes estudos sustentarem a hipótese da ocorrência de translocação bacteriana, eles não demonstram que a bactéria detectada no sangue e em sítios estéreis tem efetivamente origem no TGI do animal ou paciente. Portanto, o objetivo da primeira fase deste trabalho, consistiu no desenvolvimento de um modelo experimental que comprovasse que bactérias isoladas em sítios estéreis são realmente de origem intestinal e que pudesse posteriormente viabilizar o estudo da translocação bacteriana. Para isto, realizou-se a colonização de ratos através da inoculação, via gavagem, de solução de Enterococcus faecalis resistente a vancomicina (ERV) e E. coli produtora de Beta-lactamase de espectro estendido (ESBL). O perfil de resistência destas cepas foi utilizado como marcador. Posteriormente, este estudo avaliou a translocação bacteriana em ratos submetidos a isquemia-reperfusão hepática com e sem estase venosa intestinal, utilizando o modelo de colonização. Quarenta e seis animais foram divididos nos seguintes grupos: Grupo I (n=15) ratos submetidos a isquemia hepática e estase intestinal por 30 minutos, e 1h de reperfusão; Grupo II (n=15) ratos submetidos a 30 minutos de isquemia hepática parcial sem estase intestinal, e 1h de reperfusão;Grupo III (n=8) ratos controle que apenas sofreraam manipulação cirúrgica e Grupo IV (n=8) ratos controle não cirúrgico. Os grupos foram analisados em relação: a ocorrência de translocação bacteriana; proporção de animais com crescimento da cepa pré-definida de ERV e E. coli ESBL, por órgão ou tecido; Concentração de LPS no sangue portal e sistêmico. Os resultados obtidos evidenciaram presença marcante de crescimento microbiológico positivo para cepas inoculadas na maioria dos órgãos ou tecidos analisados nos diferentes grupos. Desta forma, conseguimos comprovar que a bactéria detectada em sítios estéreis tem efetivamente origem no TGI daquele animal. A translocação de bactérias, para os órgãos sólidos, ocorreu com maior freqüência nos ratos submetidos a isquemia e reperfusão com estase intestinal. A translocação bacteriana para o pulmão ocorreu com maior freqüência nos grupos cirúrgicos, inclusive controle, do que no controle não cirúrgico. A translocação de endotoxinas, medida pela concentração sangüínea sistêmica, ocorreu com maior intensidade nos ratos submetidos a isquemia e reperfusão hepática com estase intestinal. Não houve diferenças entre os grupos quanto a proporção de animais com cultura positiva no sangue sistêmico e porta e concentração de endotoxinas no sangue porta. / Bacterial translocation is defined as the passage of viable bacteria and/or their products, such as endotoxins, from inside the gastrointestinal tract (GIT) to normally sterile sites. Experimental studies demonstrate that increase of the permeability of the intestinal mucosa and other conditions such as intestinal bacterial overgrowth or host immune deficiency may be associated with this phenomenon. The occurrence of bacterial translocation has been suggested in some experimental and clinical studies. Although all these studies sustained the occurrence of the bacterial translocation but they did not demonstrate that it has effectively origin in the TGI of the animal or patient. The first objective of this study was to develop a GIT colonization experimental model in rats with resistant Enterococcus faecalis (E.faecalis) and E.coli, to be used in further studies of bacterial translocation intending, The resistance profile of these strains is used as a marker. Afterwards, this study evaluated the bacterial translocation in rats submitted to hepatic ischemic-reperfusion with or without intestinal vein stasis. Forty six animals were used as follows: Group I (n=15) mice submitted to ischemic hepatica and intestinal stasis for 30 minutes, and 1h of reperfusion; Group II (n=15) mice submitted to partial ischemic hepatica for 30 minutes without intestinal stasis, and 1h of reperfusion; Group III (n=8) control of mice which only suffered surgical manipulation and Group IV (n=8) Group of mice without surgical control. The groups were analyzed concerning: the occurrence of bacterial translocation; proportion of animals with predefined ERV and E.Coli ESBL growth increase per organ or tissue; LPS concentration in the portal and systemic blood. The results demonstrated remarkable appearance of positive microbiological growth for inoculated stains mostly in the analyzed tissues within the different groups. By this way, we were able to prove that the bacteria present in sterile sites have effectively their origin in the TGI of that animal. The bacteria translocation in solid organs occurred frequently in group I submitted to the ischemia-reperfusion with intestinal stasis. The bacterial translocation in lung occurred more frequently in the surgical groups including chirurgical control. The endotoxin in systemic blood concentration occurred more intensively in group I submitted to the ischemia-reperfusion with intestinal stasis.
24

Efeito da restrição alimentar materna durante a prenhez e lactação nos neurônios MCH e CART da área hipotalâmica lateral (LHA)

Machado, Carla de Moraes. January 2019 (has links)
Orientador: José de Anchieta de Castro e Horta Júnior / Resumo: A associação do baixo peso ao nascer com alto risco de doenças como obesidade, diabete tipo 2 e doenças cardiovasculares na vida adulta levaram à hipótese da “Origem Desenvolvimentista da Saúde e Doença” (DOHaD). Nessa hipótese, Programação se refere às adaptações executadas pelo organismo frente a insultos ocorridos durante seu desenvolvimento, gerando efeitos permanentes ou não na estrutura e função de órgãos. A nutrição materna durante o desenvolvimento do indivíduo é considerada um importante indutor de Programação, visto que a deficiência de nutrientes, durante a prenhez e a lactação, provoca alterações significativas no peso corpóreo, no balanço energético, na ingestão alimentar e na expressão de neuropeptídeos. O hormônio concentrador de melanina (MCH) e o transcrito regulado pela cocaína e anfetamina (CART) são neuropeptídeos expressos na área hipotalâmica lateral (LHA), que participam da regulação do balanço energético e do comportamento alimentar, nos quais o MCH desempenha papel orexígeno e o CART, anorexígeno. Nosso objetivo foi analisar o número e a distribuição de neurônios MCH e CART e sua ultraestrutura na LHA de ratos cujas mães foram submetidas à restrição alimentar durante a prenhez e lactação. Fêmeas prenhes Wistar foram separadas em dois grupos experimentais: grupo controle (GC), dieta padrão ad libitum, e grupo restrição calórica (GR), dieta de 50% de restrição em relação ao grupo controle durante os períodos de prenhez e lactação. Foram avaliados o núme... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The association between lower birth weight and an increased risk of obesity, diabetes type 2 and cardiovascular diseases in adult life led to Developmantal Origins of Health and Disease (DOHaD) hypothesis. In this hypothesis, programming is related to the adjustments performed by the organism to insults occurring at key stages of their development, which may lead to long-lasting effects in the organs structure and function. Maternal nutrition during critical periods of individual development is considered an important Programming inductor, since the nutrient deficiency during pregnancy and lactation causes significant changes in body weight, energy balance, food intake and neuropeptides expression. The melanin-concentrating hormone (MCH) and the cocaine- and amphetamine-regulated transcript (CART) are neuropeptides expressed in the lateral hypothalamic area (LHA) that are involved in the regulation of energy balance and feeding behavior in which MCH plays an orexigenic role and CART an anorexigenic one. Thus, our aim was to analyze the number and the distribution of MCH and CART and the ultrastructure of these neurons in the LHA of rats whose mothers were subjected to food restriction during pregnancy and lactation. After pregnancy confirmation, female Wistar rats were divided in two groups: control group (CG), ad libitum standard diet, and caloric restriction group (RG), 50% diet restriction compared to the control group during pregnancy and lactation. After birth, the numbe... (Complete abstract click electronic access below) / Doutor
25

O efeito do cimento composto de sulfato de cálcio e beta fosfato tricálcico com controle de potencial zeta sobre o reparo de defeitos ósseos críticos em calvária de ratos / The effect of calcium sulfate and beta-tricalcium phosphate composite with zeta potential control on the healing process of bone critical defects in rats

Souza, Daniel Falbo Martins de 02 July 2015 (has links)
Nos defeitos bucomaxilofaciais, a intervenção cirúrgica utilizando enxertos ou substi-tutos ósseos é indicada para reestabelecer a forma e a função perdidas. Nesse con-texto, enxertos auto?genos e alo?genos te?m sido substituídos por biomateriais osteo-condutores e reabsorvíveis. O objetivo deste trabalho foi avaliar por meio de micro-tomografia e dos aspectos histológicos do reparo ósseo, se um novo cimento bifási-co composto por sulfato de cálcio e beta fosfato tricálcico com controle de potencial zeta, poderia induzir ou conduzir a neoformação óssea em defeitos críticos, produzi-dos em calvárias de ratos. Foi realizado um defeito crítico de 8mm de diâmetro na calvária de 40 ratos Wistar machos. No grupo teste (n=20) os defeitos foram preen-chidos pelo cimento. No grupo controle (n=20) os defeitos não foram preenchidos e permaneceram apenas com o coágulo. Os animais sofreram eutanásia em 7, 14, 21 e 42 dias do pós operatório. Espécimes da região da ferida foram microtomografa-dos e posteriormente as amostras foram preparadas para análise histológica. A aná-lise histomorfológica incluiu a avaliação morfológica da histopatologia do reparo, a avaliação morfométrica da área de formação das trabéculas ósseas comparativa-mente entre os grupos. Realizamos ainda a coloração com fosfatase tartrato-resistente (TRAP) para identificação de osteoclastos. Os resultados mostraram que os defeitos preenchidos pelo cimento não apresentaram diminuição significativa da área de acordo com a progressão dos períodos pós-operatórios, pelo contrário, em alguns animais, o defeito aparentemente aumentou. A histomorfologia do reparo mostrou agrupamentos mais expressivos de células gigantes no grupo teste suge-rindo resposta a corpo estranho e osso neoformado mais maduro no grupo controle No grupo teste houve permanência do material e resposta corpo estranho até os úl-timos períodos de observação. Na histomorfometria, a área total de neoformação óssea na região da ferida foi significativamente maior e crescente com o passar do tempo experimental no grupo controle do que no grupo teste. As células gigantes apresentaram expressão histoquímica positiva para TRAP e não foram identificados osteoclastos. Concluímos que neste modelo de estudo, o cimento cerâmico não in-duziu ou conduziu a neoformação óssea de defeitos ósseos críticos criados em cal-vária de ratos sob o ponto de vista microtomográfico e histológico. / Surgical intervention employing grafts and bone substitutes is the best choice in oral and maxillofacial bone defects reconstruction for structural and functional lost. Re-garding this, autogenous and alogenous grafts have been used as osteocondutive and resorbable biomaterials. The aim of this study was to evaluate if a new bone bi-phasic composite of calcium sulfate and beta tricalcium phosphate with zeta potential control could induce or conduct bone formation in rats\' calvarias critical defects mod-el. Forty male Wistar rats underwent 8mm diameter calvaria perforation under gen-eral anesthesia. Animals were randomly allocated to group test (n=20), when the de-fects were filled with the biphasic phosphate and group control (n=20) when the wound was left just with blood clot. Animals underwent euthanasia 7, 14, 21 and 42 days after surgery. Bone calvaria specimens underwent microtomography and histo-logical processing for analysis. Histomorphological and histomorphometry were per-formed regarding aspects of bone healing evolution and new bone total area within the defect. Additionally, histological samples were tartrate-resistant phosphatase (TRAP) stained for osteoclasts identification. The results showed that defects filled by the composite did not present significant bone formation considering postoperative evolution, on the contrary it seemed that the defect area increased in some animals. The bone repair histomorphology in test-group showed expressive giant cells nests involving the ceramic material suggesting foreign body reaction. A mature bone tis-sue neoformation was significantly more intense in the control-group. In the test-group the permanence of the exogenous material caused the sustained foreign body reaction until the last observational periods. Histomorphometric analysis showed that in control-group the total area of bone formation was significantly greater and pro-gressive along the experiment than the test-group. Osteoclasts were not identified but the giant cells presented positive reaction to TRAP. It was possible to conclude that the biphasic ceramic with zeta potential control was not capable to induce or conduct bone neoformation in critical defects created in rats\' calvaria.
26

Effects of chronic methamphetamine exposure during early or late phase development in normal and social isolation reared rats / Laetitia Strauss.

Strauss, Laetitia January 2012 (has links)
Methamphetamine (MA) abuse is a fast growing drug problem, and is the second most widely abused drug world-wide. MA abuse has been linked to the development of symptoms indistinguishable from schizophrenia, referred to as MA psychosis. MA abusing individuals, who most often comprise adolescents and young adults, are 11 times more likely than the general population to develop psychosis. Of further concern is that in utero exposure to MA is also a growing problem, with more women addicts choosing MA as their primary drug. This has significant implications for the neurodevelopment of the child, with subsequent behavioural deficits later in life. Epidemiological studies suggests that in utero or early life MA exposure places a vulnerable individual at greater risk for developing schizophrenia, although this has never been formerly studied either at clinical or pre-clinical level. Animal models of early life adversity, such as post-weaning social isolation rearing (SIR), can assist in understanding the underlying mechanisms in MA abuse and vulnerability to develop MA psychosis. The aim of the current study was to investigate the long term effects of either prenatal (in utero) or early postnatal administration of MA on the development of schizophrenia-like behavioural and neurochemical abnormalities later in life. In the in utero study, pregnant female Wistar rats received either saline (Sal) or MA 5 mg/kg/day for 16 days by subcutaneous (s.c.) injection , starting on prenatal day 13 (PreND-13) up to postnatal day 2 (PostND02). Male offspring were selected for the study. On PostND 21, the animals were weaned and reared under group or isolation reared conditions for 8 weeks. In the early postnatal study, adult male Wistar rats were divided into group reared and SIR conditions from PostND21. Either group received an escalating dose of MA twice a day (0.2 mg/kg – 6 mg/kg s.c.) or Sal for 16 days, from PostND35 to PostND50. Both in utero and early postnatal groups were then subjected to various behavioural tests on PostND78, including assessment of social interaction (SI) and prepulse inhibition (PPI) of acoustic startle. Following behavioural testing, rats were sacrificed and brains snap frozen for later analysis of cortico-striatal monoamine concentrations, superoxide dismutase activity and lipid peroxidation. In the prenatally exposed group no differences in %PPI was observed, although group reared animals receiving MA and SIR animals receiving Sal or MA showed a decrease in social interactive behaviours, including approaching, time together and anogenital sniffing. SIR animals receiving Sal or MA also showed a decrease in rearing. Regarding self-directed behaviours, group reared animals receiving MA and SIR animals receiving Sal or MA showed an increase in self-grooming. Although some disturbances in regional brain monoamines were observed in the frontal cortex and striatum across the groups, this did not reach significance. A significant increase in malondialdehyde was observed in the striatum in group reared animals receiving MA as well as SIR animals receiving Sal or MA, indicating cell damage, possibly of redox origin. In the early postnatal study, %PPI was significantly reduced in group reared animals receiving MA as well as in SIR animals receiving Sal or MA. Group reared animals receiving MA and SIR animals receiving Sal or MA showed a decrease in social interactive behaviours, including rearing, approaching, time together and anogenital sniffing. Regarding self-directed behaviours and locomotor activity, self-grooming and squares crossed was significantly increased in group reared animals receiving MA and SIR animals receiving Sal or MA. A significant increase in DA was evident in the frontal cortex of SIR and grouped housed animals receiving MA. DA in the MA + SIR combination was elevated but not significantly so. None of the treatments affected striatal monoamine levels. In the group reared animals receiving MA as well as the SIR animals receiving Sal or MA, a significant decrease in SOD activity was observed in the frontal cortex, indicating the presence of oxidative stress in this brain region. None of the parameters indicated an additive effect in MA + SIR treated animals. In conclusion, prenatal exposure to MA led to some evidence of late-life behavioural and neurochemical abnormalities akin to schizophrenia, confirming its penchant for psychotogenic effects. However, chronic postnatal MA exposure was more emphatic, being as effective as SIR, a neurodevelopmental model of schizophrenia, in inducing deficits in the above-mentioned behavioural and neurochemical parameters. Thus, early adolescent abuse of MA is a significant risk factor for the later development of schizophrenia or psychosis. However, the risk appeared not to be exacerbated in a population at risk, i.e. in SIR animals. / Thesis (MSc (Pharmacology))--North-West University, Potchefstroom Campus, 2013.
27

Effects of chronic methamphetamine exposure during early or late phase development in normal and social isolation reared rats / Laetitia Strauss.

Strauss, Laetitia January 2012 (has links)
Methamphetamine (MA) abuse is a fast growing drug problem, and is the second most widely abused drug world-wide. MA abuse has been linked to the development of symptoms indistinguishable from schizophrenia, referred to as MA psychosis. MA abusing individuals, who most often comprise adolescents and young adults, are 11 times more likely than the general population to develop psychosis. Of further concern is that in utero exposure to MA is also a growing problem, with more women addicts choosing MA as their primary drug. This has significant implications for the neurodevelopment of the child, with subsequent behavioural deficits later in life. Epidemiological studies suggests that in utero or early life MA exposure places a vulnerable individual at greater risk for developing schizophrenia, although this has never been formerly studied either at clinical or pre-clinical level. Animal models of early life adversity, such as post-weaning social isolation rearing (SIR), can assist in understanding the underlying mechanisms in MA abuse and vulnerability to develop MA psychosis. The aim of the current study was to investigate the long term effects of either prenatal (in utero) or early postnatal administration of MA on the development of schizophrenia-like behavioural and neurochemical abnormalities later in life. In the in utero study, pregnant female Wistar rats received either saline (Sal) or MA 5 mg/kg/day for 16 days by subcutaneous (s.c.) injection , starting on prenatal day 13 (PreND-13) up to postnatal day 2 (PostND02). Male offspring were selected for the study. On PostND 21, the animals were weaned and reared under group or isolation reared conditions for 8 weeks. In the early postnatal study, adult male Wistar rats were divided into group reared and SIR conditions from PostND21. Either group received an escalating dose of MA twice a day (0.2 mg/kg – 6 mg/kg s.c.) or Sal for 16 days, from PostND35 to PostND50. Both in utero and early postnatal groups were then subjected to various behavioural tests on PostND78, including assessment of social interaction (SI) and prepulse inhibition (PPI) of acoustic startle. Following behavioural testing, rats were sacrificed and brains snap frozen for later analysis of cortico-striatal monoamine concentrations, superoxide dismutase activity and lipid peroxidation. In the prenatally exposed group no differences in %PPI was observed, although group reared animals receiving MA and SIR animals receiving Sal or MA showed a decrease in social interactive behaviours, including approaching, time together and anogenital sniffing. SIR animals receiving Sal or MA also showed a decrease in rearing. Regarding self-directed behaviours, group reared animals receiving MA and SIR animals receiving Sal or MA showed an increase in self-grooming. Although some disturbances in regional brain monoamines were observed in the frontal cortex and striatum across the groups, this did not reach significance. A significant increase in malondialdehyde was observed in the striatum in group reared animals receiving MA as well as SIR animals receiving Sal or MA, indicating cell damage, possibly of redox origin. In the early postnatal study, %PPI was significantly reduced in group reared animals receiving MA as well as in SIR animals receiving Sal or MA. Group reared animals receiving MA and SIR animals receiving Sal or MA showed a decrease in social interactive behaviours, including rearing, approaching, time together and anogenital sniffing. Regarding self-directed behaviours and locomotor activity, self-grooming and squares crossed was significantly increased in group reared animals receiving MA and SIR animals receiving Sal or MA. A significant increase in DA was evident in the frontal cortex of SIR and grouped housed animals receiving MA. DA in the MA + SIR combination was elevated but not significantly so. None of the treatments affected striatal monoamine levels. In the group reared animals receiving MA as well as the SIR animals receiving Sal or MA, a significant decrease in SOD activity was observed in the frontal cortex, indicating the presence of oxidative stress in this brain region. None of the parameters indicated an additive effect in MA + SIR treated animals. In conclusion, prenatal exposure to MA led to some evidence of late-life behavioural and neurochemical abnormalities akin to schizophrenia, confirming its penchant for psychotogenic effects. However, chronic postnatal MA exposure was more emphatic, being as effective as SIR, a neurodevelopmental model of schizophrenia, in inducing deficits in the above-mentioned behavioural and neurochemical parameters. Thus, early adolescent abuse of MA is a significant risk factor for the later development of schizophrenia or psychosis. However, the risk appeared not to be exacerbated in a population at risk, i.e. in SIR animals. / Thesis (MSc (Pharmacology))--North-West University, Potchefstroom Campus, 2013.
28

Dietas padrão utilizadas em experimentação animal : uma análise comparativa. / Standard diets used in animal experimentation : a comparative analysis.

Barbosa, Junia Helena Porto 12 November 2008 (has links)
Many diets of different compositions are available for use in animal experiments and have been used as standard, but they may induce adverse metabolic effects, compromising the comparison between the results of several studies. The literature records many reports of changes related to the use of these diets, however it lacks studies that compare metabolic effects of consumption of the different standard diets in animal experiments. Accordingly, the objective of this dissertation was to evaluate the metabolic effects of the consumption of diets considered standard widely used in animal research, being presented in the form of two articles: a review of the literature that gathers evidence yet little discussed by the scientific community on the feeding of laboratory animals; the second article refers to an experimental study with rats newly weaned, who received two types of diets: a commercial cereal-based, Nuvilab®, and another purified proposal by the American Institute of Nutrition, the AIN-93. Under the experimental conditions established, coefficients of protein and feeding efficiency presented significantly higher in group AIN-93 than in group Nuvilab®. The AIN-93 showed significantly higher lipid and protein digestibility than Nuvilab®. The different diets did not cause weight difference evolution of animals and histological analysis to the optical microscope of the kidneys, heart, spleen, stomach and small intestine showed no changes in the structures of these bodies, despite the different treatments. Animals fed the AIN-93 diet, regardless of age, had hepatic steatosis in frequency significantly higher than the animals that received the commercial Nuvilab®. The different diets did not cause influence on the absolute and relative weights of organs of animals, except for the absolute weight of the liver among younger animals and relative weight of the intestine among older animals. There was no influence of different diets on biochemical parameters evaluated, and the differences detected possibly resulting from the interaction between age and length of exposure of animals to diets. The markers of damage of kidney and liver function were similar and serum creatinine varied according to age. It was shown that both diets, AIN-93 and Nuvilab ®, are able to promote the growth of rats for a period of study considered subchronic. However, the occurrence of hepatic steatosis in animals fed the AIN-93 diet in pellets, reinforces the importance of tracking the standard protocols of experimentation and is indicative of nutritional inadequacies by imposing the need for further investigations to clarify which components or characteristics of this diet, widely used in animal experiments, may have contributed to this result. For instance, it is suggested that diets in the form of flour are used preferably those pellets, particularly on protocols to investigate metabolic effects. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Várias dietas de diferentes composições estão disponíveis para o uso em experimentação animal e têm sido utilizadas como padrão, mas podem induzir efeitos metabólicos distintos, comprometendo a comparação entre os resultados dos diversos estudos. A literatura registra inúmeros relatos de alterações relacionadas ao uso dessas dietas, porém, há carência de estudos que comparem os efeitos metabólicos do consumo das diferentes dietas padrão utilizadas em experimentos animais. Assim sendo, o objetivo da presente dissertação foi avaliar as repercussões metabólicas do consumo de dietas consideradas padrão, amplamente utilizadas na pesquisa animal, sendo apresentada na forma de dois artigos: uma revisão da literatura, que reúne evidências ainda pouco debatidas pela comunidade científica relativas à alimentação de animais de laboratório, e um segundo artigo, que se refere a um estudo experimental com ratos Wistar recémdesmamados, que receberam dois tipos de dieta: uma comercial à base de cereais, Nuvilab®, e outra purificada proposta pelo American Institute of Nutrition, a AIN-93. Nas condições experimentais estabelecidas, coeficientes de eficiências protéica e alimentar apresentaram-se significativamente maiores no grupo AIN-93 que no grupo Nuvilab®. A AIN-93 apresentou digestibilidades lipídica e protéica significativamente maiores que a Nuvilab®. As diferentes dietas não causaram diferença na evolução ponderal dos animais e a análise histológica ao microscópio óptico dos rins, coração, baço, estômago e intestinos não evidenciou alterações nas estruturas desses órgãos, apesar dos diferentes tratamentos. Os animais alimentados com a dieta AIN-93, independente da idade, apresentaram esteatose hepática em uma frequência significativamente maior que os animais que receberam a comercial Nuvilab®. As diferentes dietas não exerceram influência sobre os pesos absoluto e relativo dos órgãos dos animais, com exceção do peso absoluto do fígado, entre os animais mais jovens, e do peso relativo do intestino, entre os animais mais velhos. Não se observou influência das diferentes dietas sobre os parâmetros bioquímicos avaliados, sendo as diferenças detectadas possivelmente resultantes da interação entre a idade e o tempo de exposição dos animais às dietas. Os marcadores de lesão e função hepática e renal foram similares e a creatinina sérica variou em função da idade. Demonstrou-se que ambas as dietas, AIN-93 e Nuvilab®, são capazes de promover o crescimento de ratos Wistar por um período de estudo considerado subcrônico. Porém, a ocorrência de esteatose hepática nos animais alimentados com a dieta AIN-93 peletizada, reforça a importância de monitoramento de protocolos padrão de experimentação e é indicativa de inadequações nutricionais, impondo a necessidade de investigações adicionais para esclarecer que componentes ou características dessa dieta, amplamente utilizada em experimentação animal, podem ter contribuído para tal resultado. Por hora, sugere-se que a dieta AIN-93 seja oferecida preferencialmente na forma de farinha, particularmente em protocolos que investiguem efeitos metabólicos.
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Etude du stress oxydatif dans l’hypertrophie bénigne de la prostate et mise en évidence de l’effet de la propolis contre le cancer de la prostate in vivo sur un modèle animal de rat Wistar et ex vivo sur les cellules LNCaP du cancer de la prostate hormono-sensibles / Study of the oxidative stress in benign prostatic hyperplasia and the effect of propolis against prostate cancer in vivo on an animal model of Wistar rat and ex vivo on hormone-sensitive (LNCaP) prostate cancer cell lines

Zabaiou, Nada 23 October 2017 (has links)
L’HBP et le cancer de la prostate constituent les deux maladies prostatiques les plus répandues chez l’homme âgé. La compréhension de leur étiologie et de leur pathogenèse est nécessaire afin de permettre la prévention mais aussi la recherche et le développement de nouveaux agents thérapeutiques. Notre but est d’étudier l’implication du stress oxydatif dans l’HBP et d’étudier l’effet de l’extrait de propolis sur le cancer de la prostate in vivo chez le rat Wistar et in vitro sur les cellules LNCaP. Nous avons montré que : 1) Le stress oxydatif joue le rôle de promoteur dans le développement de l’HBP, 2) Le benzo(a)pyrène administré aux rats Wistar induit le développement du cancer de la prostate, 3) La propolis induit la diminution de la prolifération, de l’expression du Ki-67 (-49 %) et de l’expression de AhR chez le rat Wistar, 4) La propolis possède un effet antiprolifératif sur les cellules LNCaP via le blocage de la signalisation de AR. / BPH and prostate cancer are the two most prevalent prostatic diseases in elders. Understanding their etiology and pathogenesis is necessary in order to prevent them and to enhance both research and development of new therapeutic agents. Our goal is to study the implication of oxidative stress in BPH and to study the effect of propolis extract on prostate cancer in vivo in Wistar rats and in vitro on LNCaP cells. We have shown that: 1) Oxidative stress acts as a promoter in the development of BPH, 2) Benzo(a)pyrene administered to Wistar rats induces the development of prostate cancer, 3) Propolis induces a decrease in proliferation, Ki-67 expression (-49%) and AhR expression in the Wistar rat, (4) Propolis has an antiproliferative effect on LNCaP cells via AR signaling blockade.
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Estresse social, resiliência e inflamação : relação com comportamento tipo-depressivo

Stein, Dirson João January 2018 (has links)
Transtornos de humor tais como a depressão e a ansiedade estão entre as desordens psiquiátricas mais comuns na atualidade, com tendência de aumento do número de casos, assim como vêm ocorrendo nas últimas décadas. O Transtorno Depressivo Maior (TDM), uma desordem psiquiátrica dispendiosa e ameaçadora da vida, afeta profunda e negativamente a qualidade de vida dos indivíduos afetados e irá atingir até 20% da população em algum momento ao longo de sua existência. Porém, a descrição de sua patofisiologia segue incompleta e o principal pré-requisito para controlar a doença é entender de forma detalhada as alterações moleculares e comportamentais que a acompanham. O estresse social, como um dos principais indutores da depressão, tem sido alvo de estudos tanto clínicos quanto pré-clínicos, servindo também como um mecanismo laboratorial que auxilia pesquisadores a rastrear alterações moleculares e comportamentais dessa doença. Recentemente, sem deixar de lado as demais hipóteses, o sistema imunológico através de respostas inflamatórias, tem recebido atenção crescente e é investigado por ser potencialmente um indutor e/ou facilitador de estados depressivos, contribuindo para a patofisiologia da depressão. Além disso, considerando que o estresse não afeta a todos os indivíduos da mesma maneira, a compreensão das diferenças individuais que podem resultar em resiliência pode auxiliar pesquisadores quanto aos fatores que afetam o desenvolvimento ou não do transtorno na população. Esta tese é composta por dois artigos, e visa investigar em um modelo pré-clínico, a contribuição do estresse social por subordinação (do inglês, social defeat – SD) ao comportamento tipo-depressivo, relacionando-o com inflamação. No primeiro artigo foi revisada a literatura mais recente sobre a contribuição do SD para a ativação microglial, o principal elemento neuroinflamatório do sistema nervoso central (SNC), e sua relação com o desenvolvimento dos comportamentos tipo-ansioso e tipo-depressivo. No segundo artigo investigou-se o papel de um estressor social contínuo (21 dias consecutivos de derrota social crônica) em um grupo de ratos Wistar adultos, relacionando respostas comportamentais a alterações de marcadores imunológicos periféricos e a duas estratégias de coping. O modelo de estresse por derrota social tem sido utilizado em diversos estudos de transtornos psiquiátricos e é uma das principais formas de indução de estados tipo-depressivos em animais de laboratório. Ademais, vêm demonstrando ser útil na indução de alterações do sistema 11 imunológico, tanto centrais quanto periféricas. Exposição ao estresse por derrota social induz em células microgliais um estado de hiperativação que, dependendo do tempo de exposição, pode levar ao desenvolvimento de desordens psiquiátricas como a ansiedade e a depressão. Além disso, o protocolo de 21 dias de derrota social contínua revelou dois estilos comportamentais em ratos Wistar. As estratégias de coping passivo e ativo observadas estão relacionadas a vulnerabilidade e a resiliência, respectivamente, e foram correlacionadas com distintos perfis imunológicos periféricos. Animais resilientes apresentam comportamentos e perfil imunológico periférico que os protegem do desenvolvimento de psicopatologias associadas ao estresse. / Humor disorders such as depression and anxiety are among the currently most common disorders, with a trend to an increasing number of cases, like in the past few decades. Major Depressive Disorder (MDD) is an expensive and life-threatening psychiatric disorder that profoundly and negatively affects individual´s quality of life and will affect up to 20% of the population at some point throughout life. However, the pathophysiology of MDD remains incompletely described, and a detailed description of its molecular and behavioral alterations is one of the core prerequisites for disease control. Social stress, one of the main inducers of depression, has been the subject of both clinical and preclinical studies, and has been used as a laboratory tool to help researchers track molecular and behavioral changes of this disease. Recently, without leaving other hypotheses aside, the immune system through inflammatory responses has received increasing attention and is investigated as a potential contributor in the pathophysiology of depression. Furthermore, considering that stress does not affect all individuals to de same extend, understanding individual differences that can turn into resilience may help researchers unravel the factors that influence the development of this disorder in the population. The present dissertation is composed of two articles, aiming to investigate in a preclinical model the contribution of social defeat stress (SD) to depressive-like behavior and correlate it to inflammation. In the first article, we reviewed the most recent literature on the contribution of SD to microglial activation, the main neuroinflammatory element of the central nervous system (CNS), and its relation to the development of anxiety and depressive-like behaviors. In the second paper, we investigated the role of a continuous social stressor (21 consecutive days of chronic social defeat) in a group of adult male Wistar rats, relating behavioral responses and two different coping strategies to changes in peripheral immune markers. The social defeat stress model has been used in several studies of psychiatric disorders and is one of the main forms to induce depressive-like states in laboratory animals. Additionally, it has been shown to be useful in inducing central and peripheral immune alterations. Exposure to stress due to social defeat induces microglial cells into a state of hyperactivation that, depending on the time of exposure, can lead to the development of psychiatric disorders such as anxiety and depression. Furthermore, the 21-day protocol of continuous social defeat revealed two behavioral 13 styles in Wistar rats. The observed passive and active coping strategies are related to vulnerability and resilience, respectively, and have been correlated with different peripheral immunological profiles. Resilient animals present behaviors and a peripheral immune profile that protect them from the development of stress-associated psychopathologies.

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