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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.
151

Primary Sjögren´s Syndrome. Clinical Studies with reference to Hormonal Status, Psychiatric Symptoms and Well-Being

Valtýsdóttir, Sigrídur Th. January 2001 (has links)
<p>Primary Sjögren's syndrome (pSS) is a chronic inflammatory connective tissue disease of unknown etiology. The disease primarily involves salivary and lacrimal glands which results in oral and ocular dryness (sicca symptoms). A wide spectrum of extraglandular features from various organs may be seen. </p><p>In this thesis, the frequency of psychiatric symptoms in women with primary Sjögren's syndrome was studied and an attempt was made to assess how these symptoms might influence their well being and quality of life. The main finding was that the women with pSS suffered significantly more often from symptoms of anxiety and depression when compared with age matched, healthy females and female patients with rheumatoid arthritis. The physical and mental well-being of the patients with pSS was significantly reduced compared to patient controls. </p><p>The possible link of psychiatric symptoms to the altered function of the hypothalamic-pituitary-gonadal axis and adrenal androgen secretion was elucidated. Women with pSS have intact cortisol synthesis but reduced serum concentrations of dehydroepiandrosterone sulphate (DHEA-S) (p<0.05) and an increased cortisol/DHEA-S ratio (p<0.05), compared to healthy controls. These findings may reflect a constitutional or disease-meditated influence on adrenal steroid synthesis. Positive correlation was found between DHEA-S serum levels and quality of sexual life (p<0.01) and mental well-being (p<0.01) in women with pSS. </p>
152

Primary Sjögren´s Syndrome. Clinical Studies with reference to Hormonal Status, Psychiatric Symptoms and Well-Being

Valtýsdóttir, Sigrídur Th. January 2001 (has links)
Primary Sjögren's syndrome (pSS) is a chronic inflammatory connective tissue disease of unknown etiology. The disease primarily involves salivary and lacrimal glands which results in oral and ocular dryness (sicca symptoms). A wide spectrum of extraglandular features from various organs may be seen. In this thesis, the frequency of psychiatric symptoms in women with primary Sjögren's syndrome was studied and an attempt was made to assess how these symptoms might influence their well being and quality of life. The main finding was that the women with pSS suffered significantly more often from symptoms of anxiety and depression when compared with age matched, healthy females and female patients with rheumatoid arthritis. The physical and mental well-being of the patients with pSS was significantly reduced compared to patient controls. The possible link of psychiatric symptoms to the altered function of the hypothalamic-pituitary-gonadal axis and adrenal androgen secretion was elucidated. Women with pSS have intact cortisol synthesis but reduced serum concentrations of dehydroepiandrosterone sulphate (DHEA-S) (p&lt;0.05) and an increased cortisol/DHEA-S ratio (p&lt;0.05), compared to healthy controls. These findings may reflect a constitutional or disease-meditated influence on adrenal steroid synthesis. Positive correlation was found between DHEA-S serum levels and quality of sexual life (p&lt;0.01) and mental well-being (p&lt;0.01) in women with pSS.
153

Approaches to the parametric modeling of hormone concentrations

Miller, Robert 22 July 2013 (has links) (PDF)
Transdisciplinary research in general, and stress research in particular, requires an efficient integration of methodological knowledge of all involved academic disciplines, in order to obtain conclusions of incremental value about the investigated constructs. From a psychologist’s point of view, biochemistry and quantitative neuroendocrinology are of particular importance for the investigation of endocrine stress systems (i.e., the HPA axis, and the SNS). Despite of their fundamental role for the adequate assessment of endocrine activity, both topics are rarely covered by conventional psychological curriculae. Consequently, the transfer of the respective knowledge has to rely on other, less efficient channels of scientific exchange. The present thesis sets out to contribute to this exchange, by highlighting methodological issues that are repeatedly encountered in research on stress-related endocrine activity, and providing solutions to these issues. As outlined within this thesis, modern stress research tends to fall short of an adequate quantification of the kinetics and dynamics of bioactive cortisol. Cortisol has gained considerable popularity during the last decades, as its bioactive fraction is supposed to be reliably determinable from saliva and is therefore the most conveniently obtainable marker of HPA activity. However, a substantial fraction of salivary cortisol is metabolized to its inactivated form cortisone by the enzyme 11β-HSD2 in the parotid glands, which is likely to restrict its utility. Although the commonly used antibody-based quantification methods (i.e. immunoassays) might “involuntarily” qualify this issue to some degree (due to their inherent cross-reactivity with matrix components that are structurally-related to cortisol; e.g., cortisone), they also cause differential within-immunoassay measurement bias: Salivary cortisone has (as compared to salivary cortisol) a substantially longer half-life, which leads to an overestimation of cortisol levels the more time has passed since the onset of the prior HPA secretory episode, and thus tends to distort any inference on the kinetics of bioactive cortisol. Furthermore, absolute cortisol levels also depend on the between-immunoassay variation of antibodies. Consequently, raw signal comparisons between laboratories and studies, which are favorable as compared to effect comparisons, can hardly be performed. This finding also highlights the need for the long-sought standardization of biochemical measurement procedures. The presumably only way to circumvent both issues is to rely on quantification of ultrafiltrated blood cortisol by mass-spectrometric methods. Being partly related to biochemical considerations with research on HPA activity, a second topic arises concerning the operationalization of the construct itself: In contrast to the simple outcome measures like averaged reaction times, inclined stress researchers can only indirectly infer on the sub-processes being involved in HPA activity from longitudinally sampled hormone concentrations. HPA activity can be quantified either by (a) discrete-time, or by (b) continuous-time models. Although the former is the most popular and more convenient approach (as indicated by the overly frequent encounter of ANOVAs and trapezoidal AUC calculations in the field of psychobiological stress research), most discrete time models form rather data-driven, descriptive approaches to quantify HPA activity, that assume the existence of some endocrine resting-state (i.e., a baseline) at the first sampling point and disregard any mechanistic hormonal change occurring in between all following sampling points. Even if one ignores the fact, that such properties are unlikely to pertain to endocrine systems in general, many generic discrete time models fail to account for the specific structure of endocrine data that results from biochemical hormone measurement, as well as from the dynamics of the investigated system. More precisely speaking, cortisol time series violate homoscedasticity, residual normality, and sphericity, which need to be present in order to enable (mixed effects) GLM-based analyses. Neglecting these prerequisites may lead to inference bias unless counter-measures are taken. Such counter-measures usually involve alteration of the scale of hormone concentrations via transformation techniques. As such, a fourth-root transformation of salivary cortisol (being determined by a widely used, commercially available immunoassay) is shown to yield the optimal tradeoff for generating homoscedasticity and residual normality simultaneously. Although the violation of sphericity could be partly accounted for by several correction techniques, many modern software packages for structural equation modeling (e.g., Mplus, OpenMX, Lavaan) also offer the opportunity to easily specify more appropriate moment structures via path notation and therefore to relax the modeling assumptions of GLM approaches to the analysis of longitudinal hormone data. Proceeding from this reasoning, this thesis illustrates how one can additionally incorporate hypotheses about HPA functioning, and thus model all relevant sub-processes that give rise to HPA kinetics and dynamics. The ALT modeling framework being advocated within this thesis, is shown to serve well for this purpose: ALT modeling can recover HPA activity parameters, which are directly interpretable within a physiological framework, that is, distinct growth factors representing the amount of secreted cortisol and velocity of cortisol elimination can serve to interpret HPA reactivity and regulation in a more unambiguous way, as compared to GLM effect measures. For illustration of these advantages on a content level, cortisol elimination after stress induction was found to be elevated as compared to its known pharmacokinetics. While the mechanism behind this effect requires further investigation, its detection would obviously have been more difficult upon application of conventional GLM methods. Further extension of the ALT framework allowed to address a methodological question, which had previously been dealt with by a mere rule of thumb; what’s the optimal threshold criterion, that enables a convenient but comparably accurate classification of individuals whose HPA axis is or is not activated upon encountering a stressful situation? While a rather arbitrarily chosen baseline-to-peak threshold of 2.5 nmol/L was commonly used to identify episodes of secretory HPA activity in time series of salivary cortisol concentrations, a reanalysis of a TSST meta- dataset by means of ALT mixture modeling suggested that this 2.5 nmol/L criterion is overly conservative with modern biochemical measurement tools and should be lowered according to the precision of the utilized assay (i.e., 1.5 nmol/L). In sum, parametric ALT modeling of endocrine activity can provide a convenient alternative to the commonly utilized GLM-based approaches that enables the inference on and quantification of distinct HPA components on a theoretical foundation, and thus to bridge the gap between discrete- and continuous-time modeling frameworks. The implementation of the outlined modeling approaches by the respective statistical syntaxes and practical guidelines being derived from the comparison of cortisol assays mentioned above, are provided in the appendix of the present thesis, which will hopefully help stress researchers to directly quantify the construct they actually intend to assess.
154

A Single Neonatal Injury Induces Life-Long Adaptations In Stress And Pain Responsiveness

Victoria, Nicole C 27 August 2013 (has links)
Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 30% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of injury, remains unclear. We have previously reported in rats that inflammation experienced on the day of birth permanently upregulates central opioid tone, resulting in a significant reduction in adult pain sensitivity. However, the impact on early life pain on anxiety- and stress-related behavior and HPA axis regulation is not known. Therefore the goal of this dissertation was to determine the long-term impact of a single neonatal inflammatory pain experience on adult anxiety- and stress-related responses. Neuroanatomical changes in stress-associated neurocircuits were also examined. As the endogenous pain control system and HPA axis are in a state of exaggerated developmental plasticity early in postnatal life, and these systems work in concert to respond to noxious or aversive stimuli, this dissertation research aimed to answer the following questions: (1) Does neonatal injury produce deficits in adult stress-related behavior and alter stress-related neuroanatomy through an opioid-dependent mechanism? (2) Does neonatal injury alter receptor systems regulating the activation and termination of the stress response in adulthood? (3) Are stress- and pain-related neurotransmitters altered within the first week following early life pain? (4) Is early activation of the pain system necessary for the long-term changes in anxiety- and stress-related behavior? Together these studies demonstrate the degree, severity and preventability of the long-term deficits in stress responding associated with a single painful experience early in life. The goal of this research is to promote change in the treatment of infant pain in the NICU to reduce long-term sensory and mental health complications associated with prematurity.
155

A Single Neonatal Injury Induces Life-Long Adaptations In Stress And Pain Responsiveness

Victoria, Nicole C 27 August 2013 (has links)
Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 30% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of injury, remains unclear. We have previously reported in rats that inflammation experienced on the day of birth permanently upregulates central opioid tone, resulting in a significant reduction in adult pain sensitivity. However, the impact on early life pain on anxiety- and stress-related behavior and HPA axis regulation is not known. Therefore the goal of this dissertation was to determine the long-term impact of a single neonatal inflammatory pain experience on adult anxiety- and stress-related responses. Neuroanatomical changes in stress-associated neurocircuits were also examined. As the endogenous pain control system and HPA axis are in a state of exaggerated developmental plasticity early in postnatal life, and these systems work in concert to respond to noxious or aversive stimuli, this dissertation research aimed to answer the following questions: (1) Does neonatal injury produce deficits in adult stress-related behavior and alter stress-related neuroanatomy through an opioid-dependent mechanism? (2) Does neonatal injury alter receptor systems regulating the activation and termination of the stress response in adulthood? (3) Are stress- and pain-related neurotransmitters altered within the first week following early life pain? (4) Is early activation of the pain system necessary for the long-term changes in anxiety- and stress-related behavior? Together these studies demonstrate the degree, severity and preventability of the long-term deficits in stress responding associated with a single painful experience early in life. The goal of this research is to promote change in the treatment of infant pain in the NICU to reduce long-term sensory and mental health complications associated with prematurity.
156

Hippocampal neuroplasticity and neurogenesis in major depressive disorder: a high field MRI study

Huang, Yushan Yu Xiang Unknown Date
No description available.
157

Modulation of Hypothalamic-pituitary-Adrenal Axis Parameters by Teneurin C-terminal Associated Peptide (TCAP)-1

De Almeida, Reuben Ricardo Joaquim 21 November 2012 (has links)
Teneurin C-terminal associated peptides (TCAP) are a family of bioactive peptides found on the terminal exon of the four teneurin genes. TCAP-1 is found within brain regions that modulate the activity of corticotropin-releasing factor (CRF), which is the principal neuropeptide regulator of the hypothalamic-pituitary-adrenal (HPA) axis. TCAP-1 has suppressive effects on CRF-induced anxiety behaviours in rats. However, previous studies determined that TCAP-1 does not act directly on the CRF receptors (CRFR). Thus, I postulate that TCAP-1 may act centrally to modify elements of the HPA axis. Using an immortalized mouse hippocampal cell line, I tested the hypothesis that TCAP acts either downstream of CRFR activation, or on the regulation of the glucocorticoid receptors (GCR), which modulate CRF actions. These studies indicate that TCAP-1 represents a novel peptide in the regulation of stress related systems, which acts independently of either CRF-, or glucocorticoid- mediated signal transduction and transcription.
158

Modulation of Hypothalamic-pituitary-Adrenal Axis Parameters by Teneurin C-terminal Associated Peptide (TCAP)-1

De Almeida, Reuben Ricardo Joaquim 21 November 2012 (has links)
Teneurin C-terminal associated peptides (TCAP) are a family of bioactive peptides found on the terminal exon of the four teneurin genes. TCAP-1 is found within brain regions that modulate the activity of corticotropin-releasing factor (CRF), which is the principal neuropeptide regulator of the hypothalamic-pituitary-adrenal (HPA) axis. TCAP-1 has suppressive effects on CRF-induced anxiety behaviours in rats. However, previous studies determined that TCAP-1 does not act directly on the CRF receptors (CRFR). Thus, I postulate that TCAP-1 may act centrally to modify elements of the HPA axis. Using an immortalized mouse hippocampal cell line, I tested the hypothesis that TCAP acts either downstream of CRFR activation, or on the regulation of the glucocorticoid receptors (GCR), which modulate CRF actions. These studies indicate that TCAP-1 represents a novel peptide in the regulation of stress related systems, which acts independently of either CRF-, or glucocorticoid- mediated signal transduction and transcription.
159

Hypotalamo-hypofýzo-gonádová osa a epilepsie: vzájemné vztahy / The hypothalamic-pituitary-gonadal axis and epilepsy: mutual relationships

Čuchalová, Marcela January 2018 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Science Author: Marcela Čuchalová Supervisor: doc. MUDr. Josef Herink, DrSc. Title of diploma thesis: The hypothalamic - pituitary - gonadal axis and epilepsy: mutual relationships The content of the diploma thesis is an overview of the anatomy and physiology of the hypothalamic-pituitary-gonadal axis (HHG). Further chapters are devoted to the influence of epilepsy on HHG function, the effect of HHG hormones on epileptic activity itself. The effect of anti-epileptics on HHG functions will also be elucidated. The second part of the diploma thesis deals with separate chapters - catamenial epilepsy and epilepsy during pregnancy. Keywords: antiepileptic drugs, gonadotropin, hypothalamic-pituitary-gonadal axis, prolactin, sex hormones, temporal lobe epilepsy.
160

Influência da exposição in utero e lactacional ao anti-inflamatório ibuprofeno repercussão tardia em parâmetros reprodutivos masculinos, em ratos /

Balin, Paola da Silva January 2018 (has links)
Orientador: Arielle Cristina Arena / Resumo: Os anti-inflamatórios não esteroidais (AINEs), entre eles o Ibuprofeno, são amplamente utilizados para o tratamento da dor e de processos inflamatórios, e estão entre as classes de medicamentos mais utilizadas por gestantes. Através da inibição da enzima ciclo-oxigenase, os AINEs inibem a síntese de prostaglandinas, compostos eicosanoides que atuam não somente como mediadores e moduladores inflamatórios, mas também em diversos processos fisiológicos do organismo, como no mecanismo de diferenciação sexual hipotalâmica. O processo de masculinização do hipotálamo é dependente de testosterona, que por ação da enzima citocromo P450 aromatase, é convertida em estradiol. Este hormônio regula positivamente a expressão da enzima ciclo-oxigenase no hipotálamo, aumentando a produção de prostaglandina do subtipo E2 (PGE2), que atua aumentando a formação de espinhas dendríticas no núcleo sexualmente dimórfico da área pré-optica (SDN-POA). Em virtude da importância da PGE2 no processo de diferenciação sexual hipotalâmica, torna-se preocupante o uso de anti-inflamatórios durante a gestação. Desta forma, o objetivo desse estudo foi avaliar os possíveis efeitos resultantes da exposição in utero e lactacional ao ibuprofeno e suas repercussões tardias sobre parâmetros reprodutivos masculinos em ratos machos. Para tanto, ratas prenhes foram expostas a três doses de ibuprofeno (10; 30; 60 mg/kg) entre a última semana de prenhez (Dias gestacionais 15-21) até o final da lactação (Dias pós-natal 21)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Non-steroidal anti-inflammatory drugs (NSAID), including Ibuprofen, are widely used in the treatment of pain and inflammatory processes, and are of the most commonly classes of drugs used by pregnant women. By inhibiting the cyclooxygenase enzyme (COX), NSAID inhibit the synthesis of prostaglandins, eicosanoids compounds that act not only as mediators and inflammatory modulators, but also in various physiological processes of the organism, such as in the mechanism of sexual hypothalamic differentiation. The hypothalamus masculinization process is testosterone dependent, which by action of the aromatase cytochrome P450 enzyme is metabolized to estradiol. This hormone upregulates the expression of COX enzyme in the hypothalamus, increasing the production of prostaglandin E2, which acts by increasing the formation of dendritic spines in the neurons of the sexually dimorphic nucleus of the preoptic area in males (SDN-POA). Due to the importance of prostaglandin E2 in the process of hypothalamic sexual differentiation, the use of anti-inflammatory drugs during pregnancy is of concern. Thus, the aim of this study was to evaluate the possible effects resulting from in utero and lactation exposure to non-steroidal anti-inflammatory ibuprofen and its late repercussions on male reproductive parameters in male rats. For this, pregnant rats were exposed to three doses of ibuprofen (10; 30; 60 mg/kg) between the last week of pregnancy (Gestational Days 15-21) until the end of lactation (P... (Complete abstract click electronic access below) / Mestre

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