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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.
71

Mechanisms involved in maintaining the corpus luteum during the first two months of pregnancy / Mecanismos envolvidos na manutenção do corpo lúteo durante os dois primeiros meses de gestação

Drum, Jéssica Nora 28 June 2019 (has links)
The progesterone (P4) produced by the corpus luteum (CL) is essential for maintenance of pregnancy. On the other hand, the interferon tau (IFNT) produced by the embryo during elongation process, besides being the primary signal for recognition, also is responsible for maintenance of the CL during early pregnancy. The presence of oxytocin receptors (OXTR) in endometrium during expected time of luteolysis is determinant for trigger the uterine release of prostaglandin F2∝ (PGF), which is in charge of CL regression. The IFNT avoid the luteolysis by suppressing the OXTR appearance. However, during second month, accessory CLs are able to regress, indicating that the PGF release occurs with the advancing of the pregnancy and the mechanisms that initiated luteolysis are recovered. Therefore, failures in maintenance of the CL can cause luteolysis and pregnancy loss during this period of 30 to 60 days, which is one of the most important problems in reproductive efficiency in cattle, specially when in vitro produced (IVP) embryos are transferred. Two experiments were designed to study this factors, focused on point when uterus recover its PGF release during pregnancy and to identify possible differences between those mechanisms on pregnancies from IVP or artificial insemination (AI) embryos. The first study evaluated circulating PGF metabolite (PGFM) after an oxytocin challenge throughout first two months of pregnancy in lactating Holstein cows. Treatment with oxytocin did not affected PGFM concentration in d11 pregnant (P) and non-pregnant (NP), on d18 had a little increase in P cows, while increased 2-fold in NP cows. Oxytocin-induced PGFM in P cows on day 25 was greater than d18 P, however was lower than P cows on d53 and d60. Days 32, 39 and 46 of pregnancy had intermediate response. The second study evaluated the oxytocin-induced PGFM in Nelore cows pregnant from AI or IVP embryos on days 17 and 31, and its association with factors that can impact in success of the pregnancy, such as P4 levels, conceptus length on d18 and size of the embryo on d32. Also, OXTR and interferon-stimulated gene 15 (ISG15) gene expression were evaluated and located in uterine endometrium. Embryo size on d32 and P4 on d31, were higher in AI than IVP. Cows from IVP on d17 presented lower oxytocin-induced PGFM than AI in the same day, however, d31 for both groups had higher PGF release after oxytocin. On d31 there was similar PGFM increase in synchronized non-inseminated group (NI). The OXTR are highly suppressed on pregnant cows on d18, especially in IVP group, but were high expressed in NI cows and on d32 for both groups, AI being higher than IVP at this day. The ISG15 had irrelevant expression on NI and d32 groups, while had extremely high expression in d18 pregnant cows for both groups. Concluding, the CL in early pregnancy is maintained by PGF release suppression, while during second month there is oxytocin-induced PGF release, suggesting that other mechanisms are responsible for maintaining CL after d25. In addition, these results demonstrate there are signaling differences between IVP and AI pregnancies, impacting the molecular and endocrine environment that influences PGF release during these time points. / A progesterona (P4) produzida pelo corpo lúteo (CL) é essencial para a manutenção da gestação. Por sua vez, o interferon tau (IFNT) produzido pelo embrião durante o processo de alongamento, além de ser o sinal primário para reconhecimento e manutenção da gestação também é responsável pela manutenção do CL durante a gestação inicial. A presença de receptores de ocitocina (OXTR) no endométrio no momento esperado da luteólise é determinante para liberação uterina de prostaglandina F2∝ (PGF), a qual é responsável pela regressão do CL. O IFNT evita a ocorrência da luteólise por meio da supressão da expressão de OXTR no endométrio. Entretanto, durante o segundo mês de gestação, CLs acessórios, principalmente contralaterais são capazes de regredir, indicando que ocorre liberação de PGF pelo útero conforme a gestação avança, e os mecanismos que iniciam a luteólise são restabelecidos. Portanto, falhas na manutenção do CL podem causar luteólise e perdas gestacionais de 30 para 60 dias, um dos importantes problemas de eficiência reprodutiva em bovinos, principalmente quando embriões produzidos in vitro (PIV) são transferidos. Dois estudos foram delineados para estudar estes fatores, com foco em determinar o momento em que o útero gravídico retoma a liberação de PGF, e identificar prováveis diferenças entre estes mecanismos em gestações de embriões PIV ou de inseminação artificial (IA). O primeiro estudo avaliou a concentração circulante do metabólito de PGF (PGFM) após desafio com ocitocina durante os primeiros dois meses de gestação em vacas Holandesas lactantes. O tratamento com ocitocina não afetou a concentração de PGFM em vacas de d11 prenhes (P) e não-prenhes (NP), no d18 apresentou um ligeiro aumento em vacas P, enquanto aumentou cerca de duas vezes em relação ao nível basal em vacas NP. O aumento de PGFM induzido por ocitocina em vacas P no dia 25 foi maior que P em d18, entretanto foi menor que vacas P nos dias 53 e 60. Os dias 32, 39 e 46 da gestação tiveram resposta intermediária. O segundo estudo avaliou a PGFM circulante em resposta a ocitocina em vacas Nelore prenhes de embriões PIV ou IA, nos dias 17 e 31 de gestação, e sua associação com fatores que podem impactar no sucesso da prenhes, como P4 circulante, tamanho de concepto no d18, e o tamanho de embrião no d32. Além disso, foi avaliada e localizada a expressão de OXTR e do gene estimulado por interferon 15 (ISG15) no endométrio uterino. O tamanho de embrião no dia 32 e a P4 circulante no dia 31 foram maiores no grupo IA. Vacas do grupo PIV d17 apresentaram menor resposta a ocitocina na concentração de PGFM do que as de IA no mesmo dia, contudo no dia 31 ambos os grupos tiveram maior resposta do que PIV d17. As vacas do d31 dos dois grupos tiveram aumento na PGFM similar às vacas não-inseminadas (NI). Os OXTR foram altamente suprimidosnas vacas prenhes do d18, especialmente no grupo PIV, mas com alta expressão em vacas NI e no dia 32 para os dois grupos, sendo a IA com maior expressão que a PIV neste dia. O gene ISG15 apresentou expressão irrelevante em NI e d32 para IA e PIV, mas apresentou expressão extremamente alta no d18 nos dois grupos prenhes. Conclui- se que o CL na gestação inicial é mantido pela supressão da liberação de PGF, enquanto que no segundo mês, ocitocina induz liberação de PGF, sugerindo que outros mecanismos regem a manutenção do CL a partir do dia 25. Além disso, nossos resultados demonstram que há diferenças entre a sinalização de gestações provenientes de embriões PIV e IA, que impactam no ambiente molecular e endócrino, influenciando a liberação de PGF nestes momentos.
72

TheRole of the Insular Cortex in Rodent Social Affective Behavior:

Rogers-Carter, Morgan M. January 2019 (has links)
Thesis advisor: John P. Christianson / In social species, animals must detect, evaluate and respond to the states of other individuals in their group. A constellation of gestures, vocalizations, and chemosignals enable animals to convey affect and arousal to others in nuanced, multisensory ways. Observers integrate such social information with environmental cues and internal physiology to general social behavioral responses via a process called social decision-making. The mechanisms and anatomical correlates of social decision-making, particularly those that allow behavioral responses to others’ emotional states, are not fully known. Therefore, the objective of this dissertation is to broaden the anatomical understanding of social decision-making by investigating the role of the insular cortex in social behaviors that depend upon others’ emotional state. Using a novel behavioral paradigm, I present causal evidence that implicates the insular cortex and its projections to the nucleus accumbens in social affective behavior. These findings are consistent with evidence from the literature that suggests insular cortex is positioned to convey sensory cues to social brain structures to produce flexible and appropriate behavioral responses to social affective cues. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.
73

Involvement of the oxytocin system in sex-specific regulation of social behavior and sex-specific brain activation

Dumais, Kelly M. January 2016 (has links)
Thesis advisor: Alexa H. Veenema / The poorly understood, but robust sex differences in prevalence, symptom severity, and treatment responses of many psychiatric disorders characterized by social dysfunction signifies the importance of understanding the neurobiological mechanisms underlying sex differences in the regulation of social behaviors. One potential system involved is the oxytocin (OT) system. OT is an evolutionarily conserved neuropeptide that has been implicated in the regulation of a variety of social behaviors in rodents and humans. This thesis aims to clarify the role of OT in sex-specific regulation of social behavior and brain function in rats. Study 1 characterized sex differences in the OT system in the brain, and found that males show higher OT receptor (OTR) binding densities in several forebrain regions compared to females. Studies 2 and 3 then determined the relevance of these sex differences in OTR binding densities for the sex-specific regulation of social behavior using pharmacological manipulations of the OTR and in vivo measurement of OT release. Study 2 focused on the function of the OT system in the posterior bed nucleus of the stria terminalis (BNSTp), because this region showed the largest sex difference in OTR binding density, and is part of the core social behavior network. Results show that endogenous OT in the BNSTp is important for social recognition in both sexes, but that exogenous OT facilitated social recognition in males only. Furthermore, social recognition in males, but not in females, was associated with higher endogenous OT release in BNSTp. This study is the first to provide a link between sex differences in OTR binding density and OT release with sex-specific regulation of social recognition by OT. Study 3 focused on amygdala subregions because these regions were found to show sex-specific correlations of OTR binding density with social interest. Results show that the OT system modulates social interest in the central amygdala (CeA), but not the medial amygdala, in sex-specific ways, with activation of the OTR in the CeA facilitating social interest in males, but not in females. These results provide evidence that the CeA is a brain region involved in the sex-specific processing of social stimuli by the OT system. Finally, Study 4 examined whether sex differences in OTR binding densities in forebrain regions lead to sex-specific brain activation in response to OT. Functional magnetic resonance imaging was used to examine blood oxygen level-dependent (BOLD) activation in awake male and female rats following central or peripheral administration of OT. Central OT administration induced sex differences in BOLD activation in numerous brain regions (including several regions with denser OTR binding in males), in which males showed predominantly higher activation compared to females. Peripheral OT administration also induced sex differences in BOLD activation, but in fewer brain regions and in different brain regions compared to central OT, indicating that the pattern and the magnitude of sex differences in neural activation induced by OT strongly depend on the route of administration. Together, outcomes of this thesis provide novel insight into the sexual dimorphic structure and function of the OT system in rats, and highlights the fact that research seeking a full understanding of the role of the OT system in behavioral and brain responses is incomplete without the inclusion of both sexes. These results may be informative given the increasing popularity of the use of OT as a potential therapeutic agent in the treatment of social dysfunction in sex-biased psychiatric disorders. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.
74

Sex Differences in Oxytocin and Vasopressin V1a Receptor Binding Densities in the Mouse Brain: Focus on the Social Behavior Neural Network

Yuan, Jing Ting (Christine) January 2017 (has links)
Thesis advisor: Alexa Veenema / Thesis advisor: Nicholas Worley / Oxytocin (OT) and vasopressin (AVP) often regulate social behaviors in sex-specific ways. We hypothesized that this could be mediated by sex differences in the OT receptor (OTR) and AVP V1a receptor (V1aR) in the brain. Here, we determined whether there are sex differences in OTR and V1aR binding densities in nodes of the social behavior neural network in the mouse brain. We also compared sex differences int he OTR and V1aR in the mouse brain with those found previously in the rat brain. Although mice and rats are closely related species, they also display differences in social behavior. Therefore, we predicted to find similar as well as unique sex differences in OTR and V1aR in mice compared to rats. Generally, we found that sex differences in OTR and V1aR binding densities are region-specific and species-specific. In detail, male mice showed higher OTR binding density than female mice in the medial amygdala, anterior lateral septum, and posterior bed nucleus of the stria terminalis. This is consistent with findings in rats. Furthermore, female mice displayed higher OTR binding density in the anteroventral periventricular nucleus and ventromedial hypothalamus. This is in contrast to rats, where males showed higher OTR binding densities in these regions. Lastly, females showed higher V1aR binding density in the anterior bed nucleus of the stria terminalis. However, this sex difference was not measured in rats due to low receptor expression in this region. Overall, these findings demonstrate the importance to determine sex differences in OTR and V1aR across species to gain a better understanding of the sex-specific behavioral functions of the OT and AVP systems. / Thesis (BS) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Biology.
75

Estudo dos efeitos centrais da ocitocina sobre a percepção somatossensorial e a memória da dor em humanos / Study of central effects of oxytocin on somatosensory perception and memory of pain in humans

Silva, Jéssica Urtado da 02 February 2017 (has links)
Diversos estudos têm demonstrado a participação da ocitocina em promover a interação social presente no comportamento materno, sexual e interpessoal, bem como em processos de memória e aprendizagem. Recentemente, a influência da ocitocina sobre a modulação da percepção da dor também tem sido discutida. Estudos histológicos mostraram a presença de receptores de ocitocina em diferentes áreas cerebrais, como a substância cinzenta periaquedutal, envolvida no controle descendente da dor e o hipocampo, envolvido nos mecanismos de memória e aprendizagem aversiva. Este trabalho teve como objetivo investigar os efeitos centrais da ocitocina intranasal sobre a percepção somatossensorial e a memória da dor em humanos. O estudo foi realizado com 31 voluntários do sexo masculino, possuindo idades entre 18 e 45 anos. Para avaliar a influência da ocitocina sobre a percepção e a memória da dor, grupos placebo (solução salina) e experimental (ocitocina intranasal 24 UI ou 40 UI) foram submetidos a Testes de Quantificação Sensorial- QST, que envolveram a aplicação de estímulos térmicos (frio e calor) e mecânicos, a fim de identificar os limiares de detecção e de dor. A memória da dor percebida foi acessada pela Escala Visual Analógica, apresentada após a administração de ocitocina. Os resultados encontrados foram significativos para o efeito da ocitocina sobre o limiar de detecção mecânico (p<0,05), para o grupo ocitocina 40 UI. Ainda, foi possível observar uma tendência à atenuação da memória, frente ao estímulo doloroso frio (p= 0.09). Os demais testes realizados não apresentaram resultados significativos. Estes dados sugerem que a ocitocina, que também é liberada pelo toque não-nocivo, pode aumentar a percepção do toque cutâneo, favorecendo o estabelecimento de vínculos sociais, que são fortemente modulados pela ocitocina. Entretanto, não influencia na detecção de estímulos térmicos inócuos ou na detecção de dor mecânica e térmica, bem como na memória da dor ao calor e ao frio, apesar da clara tendência a uma possível modulação da memória da dor ao frio, o que sugere que os efeitos centrais da ocitocina podem influenciar seletivamente a memória da dor, dependendo da relevância psicobiológica do estímulo / In addition to its role in childbirth labor and lactation, oxytocin is a well-known neurohormone, having several prosocial effects. Moreover, oxytocin seems to play a significant modulatory role in painful experiences, due to its participation in central and peripheral processing of nociceptive somatosensory information. Histological studies have shown the presence of oxytocin receptors in different brain areas, such as periaqueductal gray matter, involved in descending pain control and the hippocampus, involved in memory mechanisms and aversive learning. This work aimed to investigate the effects of intranasal oxytocin on somatosensory perception and pain memory in humans. The participants were 31 healthy men (ages ranging from 18 to 45 years old). To evaluate the influence of oxytocin on the perception and memory of pain, placebo (saline) and experimental groups (intranasal oxytocin 24 IU or 40 IU) were submitted to QST- Quantitative Sensory Testing, which involved the application of thermal stimuli (cold and heat) and mechanical, in order to identify the thresholds of detection and pain. The memory of perceived pain was accessed by the Visual Analog Scale, presented after the administration of oxytocin. The results were significant for the effect of oxytocin on the mechanical detection threshold (p <0.05) for the oxytocin group 40 IU. The data showed a significant increase in tactile perception in an experimental 40 IU oxytocin group. We suggest that this effect could be the basis for the oxytocin-bonding effect via touch. Also, it was possible to observe a tendency to attenuation of the memory, in front of the cold painful stimulus (p = 0.09). The other tests performed did not present significant results. However, it does not influence the detection of harmless thermal stimuli or the detection of mechanical and thermal pain, as well as the memory of pain to heat and cold, despite the clear tendency to a possible modulation of pain memory to cold, suggesting that the central effects of oxytocin may selectively influence pain memory, depending on the psychobiological relevance of the stimulus
76

Development of oxytocin, vasopressin V1a, and mu-opioid receptor expression in the rat brain: Implications for the regulation of juvenile social novelty-seeking behavior

Smith, Caroline Jackson January 2017 (has links)
Thesis advisor: Alexa H. Veemena / Across species, the juvenile period is characterized by increased social interaction with peers and heightened novelty-seeking behavior, as compared to any other life stage. These behaviors are likely to be highly adaptive during this developmental phase. Still, an excessive novelty-seeking phenotype may predispose individuals to risk-taking and substance abuse, while too little social engagement and low novelty-seeking are characteristics of neuropsychiatry disorders such as autism. The over-arching aim of this dissertation research has been to elucidate the neural mechanisms underlying juvenile social novelty-seeking behavior. Central activation of oxytocin, vasopressin V1a, and µ-opioid receptors (OTR, V1aR, and MOR, respectively) have been implicated in the regulation of adult social behavior, but our understanding of the expression and function of OTR, V1aR, and MORs in the juvenile brain is incomplete. Therefore, in Studies 1 and 2, age differences in binding density of OTR, V1aR, and MOR throughout the rat brain were identified using receptor autoradiography. Next, in Study 3, I established the social novelty preference test, a new paradigm designed to assess the preference of juvenile rats to interact with either a novel or a familiar (cage mate) conspecific. Using this social novelty preference test, in Studies 3, 4, and 5, the functional involvement of OTR, V1aR, and MOR in the regulation of juvenile social novelty preference was characterized using both intracerebroventricular and local in-vivo pharmacological manipulations. The results of these experiments demonstrate that both OTR and MOR activation in the brain are involved in the regulation of juvenile social novelty preference, particularly acting within the nucleus accumbens. Finally, in Study 5, I investigated the impact of social isolation on juvenile social novelty preference. My findings show that social isolation potently reduces social novelty preference, which, in turn, can be restored by MOR activation in the nucleus accumbens. Taken together, this body of work significantly advances our understanding of the neural systems underlying juvenile social novelty preference, and suggests that both oxytocin and opioid systems in the brain may be potential clinical targets for restoring social novelty-seeking behavior in neurodevelopmental disorders, such as autism.
77

Expressão gênica dos receptores de estrógeno e ocitocina no endométrio, miométrio e placenta durante a gestação e parto em cadelas / Expression of the canine estrogen and oxytocin receptor genes in the endometrium, myometrium and placenta during pregnancy and parturition

Veiga, Gisele Almeida Lima da 27 June 2008 (has links)
As diversas interações hormonais durante e gestação e parto na espécie canina são parcialmente conhecidas. A resposta dos tecidos frente ao estímulo hormonal é dependente da expressão gênica de seus receptores, bem como da concentração local dos hormônios. Desta maneira, o presente estudo apresentou como objetivos: caracterizar a expressão gênica dos receptores de estrógeno e ocitocina no endométrio, miométrio e placenta, correlacionando com as concentrações séricas dos respectivos hormônios durante a gestação e o parto. As cadelas gestantes foram alocadas em 4 grupos de acordo com a idade gestacional: até 20 dias de gestação (grupo 1, n=11), de 20 a 40 dias de gestação (grupo 2, n=12), de 40 a 60 dias de gestação (grupo 3, n=12) e em pródromos do parto (grupo 4, n=11). As cadelas dos grupos 1, 2 e 3 foram submetidas à ovário-histerectomia e as cadelas do grupo 4, à cesariana seguida da ovário-histerectomia. Amostras de endométrio, miométrio e placenta foram colhidas, bem como amostras de sangue para obtenção do soro sangüíneo. A extração do RNA total e a confecção do cDNA das amostras foram realizadas a partir de kits comerciais. As reações da PCR em tempo-real foram realizadas para os genes (RNAm) do receptor do estrógeno &alpha; (RE&alpha;) e receptor da ocitocina (OTR), utilizando o 18S e RPS5 como controles endógenos. As dosagens hormonais foram realizadas por radioimunoensaio. A expressão gênica do RNAmRE&alpha; e RNAmOTR diferiram de acordo com o tecido e período gestacional. No endométrio, a expressão do RNAmRE&alpha; foi constante durante toda a gestação e parto, enquanto que o RNAmOTR foi mais expresso no grupo 4. Em relação ao miométrio, a expressão do RNAmRE&alpha; foi maior nos grupos 2 e 4, já o RNAmOTR foi mais expresso nos grupos 3 e 4. Na placenta, o RNAmRE&alpha; apresentou maior expressão nos grupos 1 e 2, e o RNAmOTR não sofreu mudanças durante a gestação e o parto. As concentrações séricas de ocitocina mantiveram-se constantes, enquanto os níveis estrogênicos aumentaram a partir de 40 dias de gestação até o início do parto. Conclui-se que a expressão gênica dos RE&alpha; e OTR diferem de maneira temporal durante a gestação e o parto nos tecidos avaliados e as concentrações séricas de ocitocina não interferem na expressão gênica de tais receptores, enquanto os níveis de estrógeno elevam-se ao final da gestação, sendo possível atribuir a tal perfil a diferente modulação dos RE&alpha; e OTR nos tecidos estudados. / Several hormone interactions during pregnancy and parturition in the canine species are still unknown. Tissue response to hormonal stimulation is dependent on the expression of its receptor gene, as well as of the local hormonal concentration. Hence, the present study aimed to characterize the expression of the canine estrogen and oxytocin receptor genes in the endometrium, myometrium and placenta and its correlation with blood levels of the referred hormones during pregnancy and parturition. Pregnant bitches were allocated into 4 groups according to the gestational period: up to 20 days of pregnancy (Group 1, n=11), from 20 to 40 days of pregnancy (Group 2, n=12), from 40 to 60 days of pregnancy (Group 3, n=12) and in the early stage of labor (Group 4, n=11). Bitches from groups 1, 2 and 3 were subjected to ovaryhisterectomy and bitches from group 4 were submitted to cesarian section followed by ovaryhistectomy. Endometrium, myometrium and placenta samples were colleted, as well as blood samples. Extraction of the total RNA and cDNA synthesis were accomplished through commercial kits. The real-time PCR reactions were performed for the estrogen-&alpha; (RE&alpha;) and oxytocin (OTR) receptor genes, using the 18S and RPS5 as control. Estrogen and oxytocin hormonal assays were performed by radioimunoassay. The results of the mRNARE&alpha; and mRNAOTR gene expression differed among gestational periods and tissues. In the endometrium, RNAmRE&alpha; expression was homogeneous during pregnancy and labor, whereas group 4 presented a higher expression of RNAmOTR. In relation to the myometrium, RNAmRE&alpha; expression increased in groups 2 and 4, whilst RNAmOTR expression was higher in groups 3 and 4. In the placenta, groups 1 and 2 presented the highest RNAmRE&alpha; expression and the RNAmOTR expression did not change during pregnancy and parturition. Blood concentration of oxytocin remained constant, while estrogen levels increased from 40 days of gestation to labor. In conclusion, the expression of canine RE&alpha; and OTR genes differed temporally during pregnancy and parturition in the experimented tissues. Oxytocin blood levels did not influence the receptor gene expression, whereas estrogen concentrations increased at the end of the gestation, possible modulating RE&alpha; and OTR expression in the canine endometrium, myometrium and placenta.
78

Development of an UFLC/MS/MS method for the comparative analysis of oxytocin and artesunate-amodiaquine for validation of field detection systems

Godin, David Andrew 03 November 2016 (has links)
Spurious, falsely-labeled, falsified or counterfeit (SFFC) pharmaceuticals are a health concern that claims hundreds of thousands of lives annually1, a violation of intellectual property rights which cost legitimate companies billions2, and a low-risk high yield revenue stream for organized crime2. While ports of entry and border control points are the primary access control points for SFFC3,4, advances in field portable detection and equipment offers an increasingly effective method for the assessment of pharmaceuticals at regional centers and points of distribution. This is particularly important for less developed countries (LDC) who do not maintain satellite or regional testing facilities. As part of a proposed protocol to assess field portable detection equipment, an ultrafast liquid chromatography, tandem mass spectrometry (UFLC-MS/MS) method for the quantification of liquid formulation Oxytocin was developed. The six minute method was found to have a within run %bias of +/-16%, a linear dynamic range of 150-1000 nanograms/milliliter (ng/ml), and an accuracy within acceptability criteria for all tested concentrations. The effectiveness of three identified transition ions, 723.1, 86.2 and 70.1 Daltons, for the analysis of oxytocin by mass spectrometry was assessed across several figures of merit to include signal to noise ratio, %CV, calibration sensitivity, and analytical sensitivity. The 723.1 ion fragment was recommended for quantification, while the 70.1 dalton ion was recommended as a qualifier ion, although 86.2 also performed within acceptability criteria. A method for the UFLC-MS/MS assessment of degradation products for oxytocin was proposed for specificity testing. Degradation of oxytocin by exposure to highly acidic, basic, and thermal conditions for one hour was attempted. Formation of degraded products was not observed. Additionally, existing High Performance Liquid Chromatography (HPLC) methods for the simultaneous assessment of Artesunate and Amodiaquine HCl were modified to assess compatibility with UFLC. No method assessed produced sufficient quality signal to continue with method development.
79

Expressão gênica dos receptores de estrógeno e ocitocina no endométrio, miométrio e placenta durante a gestação e parto em cadelas / Expression of the canine estrogen and oxytocin receptor genes in the endometrium, myometrium and placenta during pregnancy and parturition

Gisele Almeida Lima da Veiga 27 June 2008 (has links)
As diversas interações hormonais durante e gestação e parto na espécie canina são parcialmente conhecidas. A resposta dos tecidos frente ao estímulo hormonal é dependente da expressão gênica de seus receptores, bem como da concentração local dos hormônios. Desta maneira, o presente estudo apresentou como objetivos: caracterizar a expressão gênica dos receptores de estrógeno e ocitocina no endométrio, miométrio e placenta, correlacionando com as concentrações séricas dos respectivos hormônios durante a gestação e o parto. As cadelas gestantes foram alocadas em 4 grupos de acordo com a idade gestacional: até 20 dias de gestação (grupo 1, n=11), de 20 a 40 dias de gestação (grupo 2, n=12), de 40 a 60 dias de gestação (grupo 3, n=12) e em pródromos do parto (grupo 4, n=11). As cadelas dos grupos 1, 2 e 3 foram submetidas à ovário-histerectomia e as cadelas do grupo 4, à cesariana seguida da ovário-histerectomia. Amostras de endométrio, miométrio e placenta foram colhidas, bem como amostras de sangue para obtenção do soro sangüíneo. A extração do RNA total e a confecção do cDNA das amostras foram realizadas a partir de kits comerciais. As reações da PCR em tempo-real foram realizadas para os genes (RNAm) do receptor do estrógeno &alpha; (RE&alpha;) e receptor da ocitocina (OTR), utilizando o 18S e RPS5 como controles endógenos. As dosagens hormonais foram realizadas por radioimunoensaio. A expressão gênica do RNAmRE&alpha; e RNAmOTR diferiram de acordo com o tecido e período gestacional. No endométrio, a expressão do RNAmRE&alpha; foi constante durante toda a gestação e parto, enquanto que o RNAmOTR foi mais expresso no grupo 4. Em relação ao miométrio, a expressão do RNAmRE&alpha; foi maior nos grupos 2 e 4, já o RNAmOTR foi mais expresso nos grupos 3 e 4. Na placenta, o RNAmRE&alpha; apresentou maior expressão nos grupos 1 e 2, e o RNAmOTR não sofreu mudanças durante a gestação e o parto. As concentrações séricas de ocitocina mantiveram-se constantes, enquanto os níveis estrogênicos aumentaram a partir de 40 dias de gestação até o início do parto. Conclui-se que a expressão gênica dos RE&alpha; e OTR diferem de maneira temporal durante a gestação e o parto nos tecidos avaliados e as concentrações séricas de ocitocina não interferem na expressão gênica de tais receptores, enquanto os níveis de estrógeno elevam-se ao final da gestação, sendo possível atribuir a tal perfil a diferente modulação dos RE&alpha; e OTR nos tecidos estudados. / Several hormone interactions during pregnancy and parturition in the canine species are still unknown. Tissue response to hormonal stimulation is dependent on the expression of its receptor gene, as well as of the local hormonal concentration. Hence, the present study aimed to characterize the expression of the canine estrogen and oxytocin receptor genes in the endometrium, myometrium and placenta and its correlation with blood levels of the referred hormones during pregnancy and parturition. Pregnant bitches were allocated into 4 groups according to the gestational period: up to 20 days of pregnancy (Group 1, n=11), from 20 to 40 days of pregnancy (Group 2, n=12), from 40 to 60 days of pregnancy (Group 3, n=12) and in the early stage of labor (Group 4, n=11). Bitches from groups 1, 2 and 3 were subjected to ovaryhisterectomy and bitches from group 4 were submitted to cesarian section followed by ovaryhistectomy. Endometrium, myometrium and placenta samples were colleted, as well as blood samples. Extraction of the total RNA and cDNA synthesis were accomplished through commercial kits. The real-time PCR reactions were performed for the estrogen-&alpha; (RE&alpha;) and oxytocin (OTR) receptor genes, using the 18S and RPS5 as control. Estrogen and oxytocin hormonal assays were performed by radioimunoassay. The results of the mRNARE&alpha; and mRNAOTR gene expression differed among gestational periods and tissues. In the endometrium, RNAmRE&alpha; expression was homogeneous during pregnancy and labor, whereas group 4 presented a higher expression of RNAmOTR. In relation to the myometrium, RNAmRE&alpha; expression increased in groups 2 and 4, whilst RNAmOTR expression was higher in groups 3 and 4. In the placenta, groups 1 and 2 presented the highest RNAmRE&alpha; expression and the RNAmOTR expression did not change during pregnancy and parturition. Blood concentration of oxytocin remained constant, while estrogen levels increased from 40 days of gestation to labor. In conclusion, the expression of canine RE&alpha; and OTR genes differed temporally during pregnancy and parturition in the experimented tissues. Oxytocin blood levels did not influence the receptor gene expression, whereas estrogen concentrations increased at the end of the gestation, possible modulating RE&alpha; and OTR expression in the canine endometrium, myometrium and placenta.
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Oxytocins påverkan på relationella upplevelser under sensorisk deprivation : och hur dessa modereras av anknytning.

Bell, Christina, Vigström, Anna January 2019 (has links)
Med en kombinerad kvalitativ och kvantitativ ansats genomfördes denna experimentella studie för att undersöka om och i så fall hur intranasalt oxytocin påverkar relationella upplevelser under sensorisk deprivation samt om anknytning är en modererande variabel. Resultaten (N=114) visade att intranasalt oxytocin inte påverkade antal eller förekomst av relationella upplevelser i sensorisk deprivation, jämfört med placebo. Det fanns inte heller något stöd för att typ av behandling hade några interaktionseffekter med anknytningsdimensionerna ångest och undvikande. En tänkbar anledning till de uteblivna resultaten kan vara att många deltagare upplevde den sensoriska deprivationen som något obehaglig, vilket kan ha gjort att experimentets design inte fungerade som avsett. Explorativa tester visade att intranasalt oxytocin påverkade förekomsten av negativa kontra positiva/neutrala relationella upplevelser. De som fick oxytocin hade i lägre utsträckning negativa och i högre utsträckning positiva eller neutrala relationella upplevelser under den sensoriska deprivationen, jämfört med de som fick placebo. Studien bidrar till mer osäkerhet kring effekterna av intranasalt oxytocin och motiverar vidare forskning.

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