Academic literature on the topic 'Basal Cortisol'
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Journal articles on the topic "Basal Cortisol"
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Karaca, Z., F. Tanriverdi, H. Atmaca, C. Gokce, G. Elbuken, A. Selcuklu, K. Unluhizarci, and F. Kelestimur. "Can basal cortisol measurement be an alternative to the insulin tolerance test in the assessment of the hypothalamic–pituitary–adrenal axis before and after pituitary surgery?" European Journal of Endocrinology 163, no. 3 (September 2010): 377–82. http://dx.doi.org/10.1530/eje-10-0229.
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BackgroundThe aims of this study were to evaluate the validity of preoperative basal serum cortisol levels measured in predicting preoperative adrenal insufficiency and also the validity of basal serum cortisol levels and early postoperative insulin tolerance test (ITT) in predicting postoperative adrenal insufficiency.MethodsThe study was prospectively designed and included 64 patients who underwent pituitary surgery for conditions other than Cushing's disease. An ITT was performed preoperatively, on the 6th postoperative day and at the 1st postoperative month. Basal serum cortisol levels were measured on the 2nd, 3rd, 4th, 5th, and 6th postoperative days.ResultsPatients with a preoperative basal cortisol level of <165 nmol/l (6 μg/dl) showed insufficient cortisol response and those with levels higher than 500 nmol/l (18 μg/dl) had sufficient cortisol response to the preoperative ITT. The positive predictive value of the ITT performed on the 6th postoperative day was 69.7%, and the negative predictive value in predicting adrenal insufficiency at the 1st postoperative month was 58%. Patients were considered to have an insufficient cortisol response to ITT at the 1st postoperative month if their basal cortisol levels were <193 nmol/l (7 μg/dl) or 220 nmol/l (8 μg/dl) or 193 nmol/l (7 μg/dl) or 165 nmol/l (6 μg/dl) or 83 nmol/l (3 μg/dl) on the 2nd–6th postoperative days respectively.ConclusionSerum basal cortisol levels may be used as the first-line test in the assessment of the hypothalamic–pituitary–adrenal axis both preoperatively and postoperatively. Dynamic testing should be limited to the patients with indeterminate basal cortisol levels.
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Lee, Hwa-Yong, Tomas J. Acosta, Michiyo Tanikawa, Ryosuke Sakumoto, Junichi Komiyama, Yukari Tasaki, Mariusz Piskula, Dariusz J. Skarzynski, Masafumi Tetsuka, and Kiyoshi Okuda. "The role of glucocorticoid in the regulation of prostaglandin biosynthesis in non-pregnant bovine endometrium." Journal of Endocrinology 193, no. 1 (April 2007): 127–35. http://dx.doi.org/10.1677/joe.1.06975.
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To determine whether glucocorticoids (GCs) play a role in regulating uterine function in cow, the present study examined the expression of mRNA encoding GC receptor (GC-R) α, 11β-hydroxysteroid dehydrogenase (11-HSD) type 1 and type 2, and the activity of 11-HSD1 in bovine endometrial tissue throughout the estrous cycle. We also studied the effects of cortisol on basal, oxytocin (OT)- and tumor necrosis factor-α (TNFα)-stimulated prostaglandin (PG) production. A quantitative real-time PCR analysis revealed that GC-Rα mRNA was expressed more strongly in the mid-luteal stage (days 8–12) than in the other stages. In contrast to GC-Rα mRNA expression, 11-HSD1 mRNA expression was greater in the follicular stage than in the other stages, whereas 11-HSD2 mRNA expression was lowest in the follicular stage. The activity of 11-HSD1 was greater in the follicular stage and estrus than in the other stages and was lowest in the mid-luteal stage. Cortisone was dose-dependently converted to cortisol in the cultured endometrial tissue. Although cortisol did not affect either the basal or OT-stimulated production of PGs in the cultured epithelial cells, the production of PGs stimulated by TNFα in the stromal cells was suppressed by cortisol (P < 0.05). Cortisol suppressed basal prostaglandin (PG)F2α without affecting basal PGE2 production in the stromal cells. The overall results suggest that the level of cortisol is locally regulated in bovine endometrium throughout the estrous cycle by 11-HSD1, and that cortisol could act as a luteoprotective factor by selectively suppressing luteolytic PGF2α production in bovine endometrium.
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Maffazioli, Giovana D. N., Tania A. S. S. Bachega, Sylvia A. Y. Hayashida, Larissa G. Gomes, Helena P. L. Valassi, Jose A. M. Marcondes, Berenice B. Mendonca, Edmund C. Baracat, and Gustavo A. R. Maciel. "Steroid Screening Tools Differentiating Nonclassical Congenital Adrenal Hyperplasia and Polycystic Ovary Syndrome." Journal of Clinical Endocrinology & Metabolism 105, no. 8 (June 12, 2020): e2895-e2902. http://dx.doi.org/10.1210/clinem/dgaa369.
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Abstract Purpose To analyze the performance of basal 17OH-progesterone (17OHP) levels versus the basal 17OHP/cortisol ratio in nonclassical congenital adrenal hyperplasia (NCAH) and polycystic ovary syndrome (PCOS) differential diagnosis. Basal 17OHP levels >10 ng/mL have been used to confirm NCAH diagnosis without the adrenocorticotropic hormone (ACTH) test; however, the optimal cutoff value is a matter of debate. Methods A cross-sectional study was performed at the endocrinology and gynecological endocrinology outpatient clinics of a tertiary hospital. A total of 361 patients with PCOS (age 25.0 ± 5.3 years) and 113 (age 19.0 ± 13.6 years) patients with NCAH were enrolled. Basal and ACTH-17OHP levels were measured by radioimmunoassay, and CYP21A2 molecular analysis was performed to confirm hormonal NCAH diagnosis. Receiver operating characteristic curve analysis compared basal 17OHP levels and the 17OHP/cortisol ratio between NCAH and PCOS patients. Results Basal 17OHP levels were higher in NCAH patients than in those with PCOS (8.85 [4.20-17.30] vs 1.00 [0.70-1.50] ng/mL; P < 0.0001), along with 17OHP/cortisol ratio (0.86 [0.47-1.5]) vs 0.12 [0.07-0.19]; P < 0.0001, respectively). Basal 17OHP levels and the 17OHP/cortisol ratio were strongly correlated in both groups (rho = 0.82; P < 0.0001). Areas under the curves for basal 17OHP levels (0.9528) and the 17OHP/cortisol ratio (0.9455) were not different to discriminate NCAH and PCOS (P > 0.05). Basal 17OHP level >5.4 ng/mL and 17OHP/cortisol ratio >2.90 had 100% specificity to identify NCAH. Main Conclusions Basal 17OHP levels >5.4 ng/mL can be used to perform differential diagnoses between NCAH and PCOS, dismissing the ACTH test. The basal 17OHP/cortisol ratio was not superior to basal 17OHP levels in this scenario.
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de Vries, Friso, Daniel J. Lobatto, Leontine E. H. Bakker, Wouter R. van Furth, Nienke R. Biermasz, and Alberto M. Pereira. "Early postoperative HPA-axis testing after pituitary tumor surgery: reliability and safety of basal cortisol and CRH test." Endocrine 67, no. 1 (September 25, 2019): 161–71. http://dx.doi.org/10.1007/s12020-019-02094-6.
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Abstract Purpose To assess the reliability and safety of a postsurgical evaluation strategy of adrenal function using CRH stimulation and basal cortisol concentrations after transsphenoidal pituitary surgery. Methods Retrospective cohort study of all patients undergoing endoscopic transsphenoidal surgery from 2010 to 2017, in whom early postoperative basal cortisol and/or CRH-stimulated cortisol secretion were available, including confirmation of adrenal function during follow-up. Patients with Cushing’s disease were excluded. Optimal test performances were assessed using ROC analysis. Results A total of 156 patients were included. Sensitivity and specificity of the CRH test were 78% and 90%, respectively, and 86% and 92% for basal cortisol, respectively, using an optimal cutoff of 220 nmol/L. Eight patients had false-negative test results with the CRH test (normal test but adrenal insufficient at follow-up), and six patients with basal cortisol, the majority of which had multiple pituitary hormone deficiencies and fluid imbalances. No clinical adverse events occurred in patients with false-negative test results. The diagnostic performance of a single basal cortisol measurement was superior to the CRH test. Conclusions The early postoperative basal cortisol is a safe and simple measurement to guide (dis)continuation of hydrocortisone replacement. However, disturbing factors, e.g., sodium balance disorders, contraceptives, untreated hypopituitarism, and illness impact the interpretation and in those cases this measure is unreliable. We propose an algorithm in which hydrocortisone replacement at discharge is based on basal cortisol <220 nmol/L on postoperative day 2 or 3 in a stable condition.
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Boesgaard, Søren, Claus Hagen, Anders Nyboe Andersen, Henning Djursing, and Mogens Fenger. "Cortisol secretion in patients with normoprolactinemic amenorrhea." Acta Endocrinologica 118, no. 4 (August 1988): 544–50. http://dx.doi.org/10.1530/acta.0.1180544.
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Abstract. Patients with functional amenorrhea have raised central dopaminergic activity and opioid-mediated GnRH inhibition leading to inhibition of hypothalamic-pituitary-ovarian function. In the present study, basal serum cortisol and ACTH levels were measured in normoprolactinemic amenorrheic patients with (N = 14) and without (N = 7) insulin-dependent diabetes mellitus. Basal serum cortisol levels was significantly (P < 0.01) elevated in patients with normoprolactinemic amenorrhea compared with normal women. Basal serum cortisol was significantly (P < 0.02) elevated in amenorheic diabetic patients compared with menstruating diabetic women. In the amenorrheic groups both cortisol and ACTH levels increased significantly (P <0.01) after dopamine D-2 receptor blockade, whereas no hormonal changes occurred in the control groups. It is concluded that patients with normoprolactinemic amenorrhea have elevated basal serum cortisol, the reason probably being hypersecretion of corticotropin-releasing hormone. Secondly that dopaminergic blockade with metoclopramide stimulates ACTH and cortisol secretion in patients presumed to have raised dopaminergic activity.
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Keller-Wood, M. "Inhibition of stimulated and basal ACTH by cortisol during ovine pregnancy." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 271, no. 1 (July 1, 1996): R130—R136. http://dx.doi.org/10.1152/ajpregu.1996.271.1.r130.
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In pregnant ewes, as in pregnant women, plasma adrenocorticotropic hormone (ACTH) and cortisol concentrations are increased. Inhibition of free cortisol concentrations by dexamethasone, a synthetic glucocorticoid, is reduced in pregnant women compared with nonpregnant women. These experiments were designed to test the hypothesis that basal and stimulated ACTH concentrations are less sensitive to negative feedback inhibition by cortisol in pregnant ewes than in nonpregnant ewes. Ewes were infused with vehicle and with cortisol at two different rates (1 and 2 micrograms.kg-1.min-1) for 1 h; plasma ACTH concentrations during and after the infusion and after subsequent stimulation by hypotension were measured. Basal plasma ACTH concentrations during a 2-h infusion of cortisol (2 micrograms.kg-1.min-1) were also measured in undisturbed ewes. Cortisol significantly inhibited both stimulated and basal ACTH. The degree of suppression of ACTH was not reduced in the pregnant ewes compared with the nonpregnant ewes. The results indicate that both basal and stimulated ACTH are sensitive to negative feedback inhibition by cortisol during ovine pregnancy.
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Žarković, Miloš, Svetlana Ignjatović, Marijana Dajak, Jasmina Ćirić, Biljana Beleslin, Slavica Savić, Mirjana Stojković, Petar Bulat, and Božo Trbojević. "Cortisol response to ACTH stimulation correlates with blood interleukin 6 concentration in healthy humans." European Journal of Endocrinology 159, no. 5 (November 2008): 649–52. http://dx.doi.org/10.1530/eje-08-0544.
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ObjectiveInterleukin 6 (IL6) has the ability to influence each level of the hypothalamo-pituitary–adrenocortical (HPA) axis. The aim of the study was to test whether IL6 concentration correlates with the adrenal cortex response to ACTH in healthy humans. We postulated that higher basal IL6 concentration would be associated with the higher cortisol response to the stimulation.Design and methodsBasal IL6 concentration was measured and a low dose (1 μg) ACTH test was performed to assess cortisol response. Twenty-seven apparently healthy subjects (11 male, 16 female, mean age 31.1 years, age range 22–47 years) were included in the study.ResultsData are presented as mean±s.e.m. Basal IL6 level was 0.84±0.10 pg/ml. Basal cortisol was 351.9±18.3 nmol/l. Maximal cortisol during synacthen test was 653.0±20.6 nmol/l. Maximal cortisol increment was 301.1±20.0 nmol/l. IL6 concentration was not correlated with basal or maximal cortisol concentration, but correlated significantly with cortisol increment (r=0.63, 95% confidence interval) 0.42–0.83).ConclusionsIn our study, we found that higher basal IL6 concentration is associated with the higher cortisol response to ACTH stimulation. Based on previous research and our data, IL6, even in low concentrations and under physiologic conditions, modulates adrenal cortex responsivity to ACTH. Therefore, it seems that immune modulation of HPA axis is also present under physiologic and not only pathologic conditions.
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Fletcher, Andrew J. W., Xiao Hong Ma, Wen X. Wu, Peter W. Nathanielsz, Hugh H. G. McGarrigle, Abigail L. Fowden, and Dino A. Giussani. "Antenatal glucocorticoids reset the level of baseline and hypoxemia-induced pituitary-adrenal activity in the sheep fetus during late gestation." American Journal of Physiology-Endocrinology and Metabolism 286, no. 2 (February 2004): E311—E319. http://dx.doi.org/10.1152/ajpendo.00158.2003.
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This study examined the effects of dexamethasone treatment on basal hypothalamo-pituitary-adrenal (HPA) axis function and HPA responses to subsequent acute hypoxemia in the ovine fetus during late gestation. Between 117 and 120 days (term: ∼145 days), 12 fetal sheep and their mothers were catheterized under halothane anesthesia. From 124 days, 6 fetuses were continuously infused intravenously with dexamethasone (1.80 ± 0.15 μg·kg–1·h–1 in 0.9% saline at 0.5 ml/h) for 48 h, while the remaining 6 fetuses received saline at the same rate. Two days after infusion, when dexamethasone had cleared from the fetal circulation, acute hypoxemia was induced in both groups for 1 h by reducing the maternal fraction of inspired O2. Fetal dexamethasone treatment transiently lowered fetal basal plasma cortisol, but not ACTH, concentrations. However, 2 days after treatment, fetal basal plasma cortisol concentration was elevated without changes in basal ACTH concentration. Despite elevated basal plasma cortisol concentration, the ACTH response to acute hypoxemia was enhanced, and the increment in plasma cortisol levels was maintained, in dexamethasone-treated fetuses. Correlation of fetal plasma ACTH and cortisol concentrations indicated enhanced cortisol output without a change in adrenocortical sensitivity. The enhancements in basal cortisol concentration and the HPA axis responses to acute hypoxemia after dexamethasone treatment were associated with reductions in pituitary and adrenal glucocorticoid receptor mRNA contents, which persisted at 3–4 days after the end of treatment. These data show that prenatal glucocorticoids alter the basal set point of the HPA axis and enhance HPA axis responses to acute stress in the ovine fetus during late gestation.
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Gariani, Karim, Pedro Marques-Vidal, Gérard Waeber, Peter Vollenweider, and François R. Jornayvaz. "Salivary cortisol is not associated with incident insulin resistance or type 2 diabetes mellitus." Endocrine Connections 8, no. 7 (July 2019): 870–77. http://dx.doi.org/10.1530/ec-19-0251.
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Background Excessive glucocorticoid secretion has been associated with type 2 diabetes mellitus (T2DM) and other features of the metabolic syndrome. We aimed to evaluate whether basal or evening salivary cortisol may predict the occurrence of incident insulin resistance (IR) or T2DM. Method This was a prospective, population-based study derived from the CoLaus/PsyCoLaus study including 1525 participants (aged 57.7 ± 10.3 years; 725 women). A total of 1149 individuals were free from T2DM at baseline. Fasting plasma glucose and insulin were measured after a follow-up of 5.3 years. Basal and evening salivary cortisol were measured at baseline. The association between basal or evening salivary cortisol level and incidence of IR or T2DM were analyzed by logistic regression, and the results were expressed for each independent variable as ORs and 95% CI. Results After a median follow-up of 5.3 years, a total of 376 subjects (24.7%) developed IR and 32 subjects (2.1%) developed T2DM. Basal and evening salivary cortisol divided in quartiles were not associated with incidence of IR or T2DM. Multivariable analysis for age, gender, body mass index, physical activity and smoking status showed no association between basal or evening salivary cortisol and incidence of IR or T2DM. Conclusion In the CoLaus/PsyCoLaus study of healthy adults, neither basal nor evening salivary cortisol was associated with incident IR or T2DM.
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Afsar, F. Sule, Figen Isleten, and Nihal Sonmez. "Children with Atopic Dermatitis Do Not Have More Anxiety or Different Cortisol Levels Compared with Normal Children." Journal of Cutaneous Medicine and Surgery 14, no. 1 (January 2010): 13–18. http://dx.doi.org/10.2310/7750.2010.09021.
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Background: The hypothalamic-pituitary-adrenal axis has an important immunoregulatory role under stress, and stressmediated anxiety has been reported to be associated with alterations in immune functions and attenuated cortisol levels in atopic dermatitis (AD) patients. Objective: We investigated serum basal cortisol and anxiety levels in pediatric AD patients and compared them with those of controls. Methods: Basal serum cortisol levels were measured in 36 pediatric AD patients (aged 9–16 years) and 36 control subjects (aged 9–15 years). Anxiety was assessed by the trait anxiety subscale (TAI-C) of the State-Trait Anxiety Inventory for Children. The severity of AD was assessed by the objective severity scoring of AD (SCORing Atopic Dermatitis [SCORAD]). Results: Data analysis showed no statistical difference for the basal serum cortisol levels ( p = .383) and the TAI-C ( p = .730) between the two groups. No significant correlation was found between the basal cortisol values and the TAI-C scores in the AD group ( p = .290). The SCORAD index was correlated with the TAI-C scores ( p < .05) but not correlated with the basal serum cortisol values in AD patients ( p = .06). Conclusion: Children with AD do not have more anxiety or different cortisol levels when compared with normal children, but the severe symptomatology of AD itself may cause anxiety levels to increase in children with AD.
Dissertations / Theses on the topic "Basal Cortisol"
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Hawn, Sage E. "EXAMINATION OF BASAL NEUROENDOCRINE LEVELS IN OIF/OEF/OND VETERANS." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/4206.
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Abstract
EXAMINATION OF BASAL NEUROENDOCRINE LEVELS IN OIF/OEF/OND VETERANS
By Sage E. Hawn, B.S.
A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.
Virginia Commonwealth University, 2015.
Major Director: Ananda B. Amstadter, PhD.
Associate Professor
Departments of Psychiatry, Psychology, & Human and Molecular Genetics
High rates of combat exposure exist among veterans of the recent conflicts, and are associated with debilitating mental health conditions, including posttraumatic stress disorder (PTSD). Numerous psychosocial and biologic factors are associated with PTSD, including the HPA-axis. The present study aimed to compare baseline neuroendocrine levels by trauma group (PTSD, trauma exposed [TE], and non-trauma controls [NTC]) among a sample of young veterans. An exploratory aim was to examine potential moderators of the relation between PTSD and basal cortisol/ACTH. Group differences in cortisol were nominally significant, with the NTC group having significantly higher cortisol than the PTSD group. Sleep disturbance was the only moderator of this relationship in cortisol, although lifetime trauma load significantly predicted basal cortisol across all models. No significant effects were demonstrated for ACTH. Examining effects of trauma on basal physiology provides a critical stepping ground for future investigations that may inform targeted prevention and intervention efforts.
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Saelzler, Ursula. "The relationship between basal cortisol levels and cognitive functioning across the adult lifespan." Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55064.
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Age-related declines in cognitive functioning have been well documented, however, there are vast individual differences in the age of onset and magnitude of these changes. This observation has spurred the investigation of the potential risk factors for cognitive decline. Chronic elevations of the steroid hormone cortisol have been shown to compromise hippocampal- and frontal cortex- dependent cognitive tasks in rodents, non-human primates and Cushing’s disease patients. Several studies have extended these findings to investigate possible associations between cortisol and cognition in aging human populations. However, these previous examinations of the role of cortisol in cognitive aging have been hampered by the predominant use of single time-point measures of cortisol, small sample sizes, limited age ranges and/or constrained cognitive testing batteries. The present cross-sectional study investigated the relationship between basal cortisol levels, indexed by a 24-hr free cortisol to creatinine ratio, and cognitive functioning on twelve cognitive outcomes in a sample of 1,853 non-demented adults aged 18 to 93 years. The results showed that elevated cortisol levels had small but significant negative effects on verbal learning and working memory performance across the lifespan and significant negative effects limited to older age on a measure of speeded processing. Longitudinal investigation is warranted to examine if within-person changes in cortisol level predict cognitive change.
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Lai, Wai Bun Benjamin. "Basal and stress-reactive cortisol levels in patients with Inflammatory Bowel Diseases." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111935.
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Inflammatory Bowel Diseases (IBD) are chronic remitting-relapsing diseases of the gastrointestinal tract. Psychological stress has long been suspected to play a role in the pathogenesis and symptom exacerbation of IBD. The goal of this study was to examine whether or not there exist any differences in the stress reactivity in patients with IBD when compared to healthy controls. Salivary cortisol was employed as a biomarker to assess the activity of the hypothalamic-pituitary-adrenal (HPA) axis---normally activated upon the perception of a psychological stressor---in IBD patients and healthy controls. Ten quiescent IBD patients were recruited and each was asked to identify a healthy age- and gender-matched friend to participate in the study to act as a control. In addition, 10 healthy age- and gender-matched subjects who were not friends of the IBD patients were recruited as a second control group. All subjects completed 4 psychological questionnaires: the NEO Personality Five Factor Inventory; the Rosenberg Self-Esteem Scale; the Perceived Stress Scale; and the Coping Inventory for Stress Situations. Subjects were asked to sample their saliva at home in order to discern their basal salivary cortisol secretion pattern. As well, subjects underwent a psychosocial stress protocol, the Trier Social Stress Test (TSST), during which saliva samples were obtained to determine their stress-reactive cortisol levels. Results from this study indicate that IBD patients and their friends are significantly more agreeable in personality and showed a blunted HPA response to the TSST, when compared to healthy non-friends. These results point to a distinct personality profile and a possible social support phenomenon among IBD patients and their friends, which may modulate HPA reactivity to psychological stress and contribute to the differential cortisol response observed.
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Dinis, Marta Correia. "Utilidade do doseamento de cortisol basal no rastreio de hipoadrenocorticismo no cão : estudo retrospetivo." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2021. http://hdl.handle.net/10400.5/21465.
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Dissertação de Mestrado Integrado em Medicina VeterináriaRESUMO - O doseamento do cortisol basal tem sido utilizado na prática clínica para excluir hipoadrenocorticismo. Quando a sua concentração é superior a 2 g/dl, esta doença é excluída. Quando é inferior, é essencial realizar um teste de estimulação com a hormona adrenocorticotrófica (ACTH) para avaliar a função adrenal. O objetivo principal deste estudo foi explorar potenciais parâmetros clínicos que permitam auxiliar a avaliação da probabilidade de um cão com hipocortisolémia apresentar um teste de estimulação com ACTH normal. Foi conduzido um estudo restrospetivo caso-controlo utilizando os dados clínicos dos cães submetidos ao doseamento de cortisol basal no Hospital Escolar Veterinário durante 30 meses. Os cães foram incluídos se apresentassem uma hipocortisolémia basal (≤2 g/dl), e após este resultado, tenha sido efectuado um teste de estimulação com ACTH. Os dados colhidos incluíram sexo, idade, raça, sinais clínicos, análise hematológica e bioquímicas (incluindo eletrólitos), resultados dos testes funcionais e alterações ecográficas. De acordo com o resultado do teste de estimulação, os cães foram divididos em dois grupos: os cães com concentrações de cortisol após estimulação ≤2g/dl foram incluídos no grupo com hipoadrenocorticismo (HAC) e cães com valores superiores foram incluídos no grupo sem hipoadrenocorticismo (N-HAC). As variáveis foram comparadas entre grupos através de testes não paramétricos (teste exato de Fisher) e testes paramétricos (teste t para amostras independentes). 35 cães foram incluídos e divididos nos grupos de estudo: 9/35 no grupo HAC e 26/35 no grupo N-HAC. Ambos os grupos apresentavam sinais gastrointestinais crónicos (66.7% no grupo HAC e 50% no grupo N-HAC). Foi observada uma concentração de cortisol basal <1g/dl em 77.8% dos cães com HAC e em 30.7% dos cães N-HAC (p=0.01; rácio de probabilidade (OR) =7.38). A presença de poliúria/polidipsia (pu/pd), relatada pelos detentores, foi mais prevalente em cães com HAC (55.6%) face aos cães N-HAC (7.7%) (p=0.01; OR=15), bem como sinais de melena/hematoquézia (55.6%-grupo HAC; 0%-grupo N-HAC) (p=4x10-4; OR=64.8). Nas alterações laboratoriais, apenas o aumento da concentração de ureia revelou uma diferença significativa entre grupos (55.6%-grupo HAC; 11.6%-grupo N-HAC) (p=0.03; OR=7.9). Em suma, cães com hipocortisolémia basal, sem aumento dos níveis de ureia, pu/pd, e sem sinais de hemorragia gastrointestinal têm maior probabilidade de ter um teste de estimulação com ACTH normal. São necessários mais estudos para estender estas conclusões a um maior número de animais e para explorar o significado da hipocortisolémia em cães com o teste de estimulação com ACTH normal.
ABSTRACT - Use of basal cortisol concentrations measurement as a screening test for hypoadrenocorticism in dogs: a retrospective study - Basal cortisol measurement has been used on clinical practice to rule out hypoadrenocorticism. When its concentration is above 2g/dL, this disease is excluded. When it is lower, it is essencial to perform a adrenocorticotrophic hormone (ACTH) stimulation test to assess adrenal function. The main goal of this study is to explore potencional clinical parameters that can aid evaluating the odds of a dog with hypocortisolemia to have normal ACTH stimulation test response. A retrospective case-control study was conducted using the clinical data of all dogs submited to the measurement of basal cortisol at a Veterinary Teaching Hospital during 30 months. Dogs were included if presented basal hypocortisolemia (≤2 g/dl) and after that result, an ACTH stimulation test was executed. Collected data included sex, age, race, clinical signs, hematological and biochemical (including electrolytes) analysis, fuctional tests results and ecographic changes. Dogs were divided in two groups, according to the ACTH stimulation test result: dogs with pos-stimulation cortisol concentrations ≤2g/dl were included on the hypoadrenocorticism (HAC) group and dogs with higher values were included on the non-hypoadrenocorticism (N-HAC) group. Variables were compared between groups using non parametric tests (Fisher’s exact test) and parametric tests (independent sample t test). 35 dogs were included and distributed on the study groups: 9/35 (25.7%) on the HAC group and 26/35 (74.3%) on the N-HAC group. Both groups showed chronic gastrointestinal signs (66.7% on the HAC group and 50% on the N-HAC group). It’s was observed a basal cortisol concentration <1g/dl in 77.8% of dogs with HAC and in 30.7% of dogs with N-HAC (p=0.01; odds ratio (OR)=7.38). Polyuria/polydipsia (pu/pd) was more related by the detentor of the HAC dogs (55.6%) than by the N-HAC dogs (7.7%) (p=0.01; OR=15), as well as signs of melena/hematochezia (55.6%-HAC group; 0%-N-HAC group) (p=4x10-4; OR=64.8). About the laboratory changes, only higher values of urea concentration showed a significant difference between groups (55.6%-HAC group; 11.6%-N-HAC group) (p=0.03; OR=7.9). In summary, dogs with basal hypocortisolemia, without high urea levels, pu/pd, and gastrointestinal hemorrhage signs have higher chances to have a normal ACTH stimulation test. Further studies are needed, to extend these conclusions to a larger number of animals and to explore the relevance of hypocortisolemia in dogs with normal ACTH stimulation test.
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Mendonça-Furtado, Olívia de. "Medidas de metabólitos de cortisol em macacos-prego (Gênero Sapajus): análise comparativa entre populações para investigação de fatores estressores." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/47/47132/tde-03122012-102144/.
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Estudos da fisiologia do estresse são de fundamental importância para a área de endocrinologia comportamental e para projetos visando à promoção do bem estar de animais cativos. Esses estudos, quando feitos com animais de vida-livre, possibilitam investigar quais estímulos ambientais ou sociais são estressores para o táxon estudado. Pouco se sabe a este respeito sobre macacos-prego (gênero Sapajus), um primata neotropical muito comum em zoológicos, criadouros e outras situações de cativeiro. Uma maior compreensão dos agentes estressores neste gênero pode contribuir para o bem estar de sujeitos cativos. Frente a isso, este trabalho objetivou: 1) investigar, a partir da variação dos níveis de glicocorticóides (GCs; hormônios ligados ao estresse), quais eventos ambientais e comportamentais são percebidos por macacos-prego selvagens como estressantes; 2) verificar a possibilidade de definir valores de referência de níveis aceitáveis (nível basal) de metabólitos fecais de glicocorticóides (MFGs a mensuração de GCs a partir de fezes permite avaliar estes hormônios de forma não-invasiva) para o gênero Sapajus; e 3) validar o protocolo experimental de extração e dosagem de hormônios fecais. Em relação aos dois primeiros objetivos, foram tomadas medidas de metabólitos fecais de glicocorticóides, e de dados ambientais e comportamentais de duas populações selvagens, uma do Parque Estadual Carlos Botelho/São Paulo (PECB) e outra da Fazenda Boa Vista/Piauí (FBV). Para a validação do protocolo experimental, foi realizado um desafio de ACTH e dexametasona com macacos-prego cativos. Análises por modelo linear generalizado misto (MLGM) mostraram diferença significativa entre os níveis basais de MFGs das duas populações estudadas, sendo maiores na população da FBV. Para esta população, foi encontrado efeito de oferta de frutos no habitat, de freqüência de encontros com outras espécies animais e de cópulas, sobre a variação mensal dos níveis basais de MFGs. Para a população do PECB, nenhuma das variáveis estudadas apresentou efeito significativo sobre a variação mensal dos níveis basais de MFGs. Já as análises individuais mostraram que interações agonísticas entre membros do grupo foram os maiores causadores de picos de MFGs nos sujeitos estudados, seguidos por fêmeas em período proceptivo e cópulas, que causaram picos não só em machos adultos, mas também em machos juvenis e nas próprias fêmeas. Os resultados do desafio de ACTH e de dexametasona validaram o protocolo experimental de extração e dosagem hormonal. Os resultados obtidos estão de acordo com pesquisas anteriores que revelaram diferenças marcantes no sistema social das duas populações, especialmente no que se refere às relações sociais de fêmeas, de acordo com as diferenças ecológicas entre as duas áreas. Além disso, sugerem que não é possível definir valores de referência de nível basal de MFGs para o gênero Sapajus, já que as duas populações diferem significativamente quanto a este aspecto. A partir deste trabalho, que é apenas o começo de uma longa jornada para a compreensão do estresse em macacos-prego selvagens, começa-se a entender quais são os estressores naturais destes animais e como eles impactam os níveis de MFGsStress physiology studies are of fundamental importance for the area of behavioral endocrinology and for projects that aim to promote the wellbeing of captive animals. When the subjects of those researches are wild animals, it is possible to investigate which environmental or social stimuli constitute stressors for this taxon. Little is known in this regard about capuchin monkeys (Sapajus genus), a neotropical primate that are constantly kept in zoos, breeders and others captive environments. A better comprehension of the stressors agents in this genus can contribute for the wellbeing of those captive individuals. Therefore this study aimed: 1) to investigate through the variation of glucocorticoids levels (GCs hormones related to stress), which environmental and behavioral events are perceived by wild capuchin monkeys as stressful; 2) access the possibility of defining basal fecal glucocorticoids metabolites levels (MFGs measuring GCs in feces is a non-invasive form of evaluate those hormones), as reference values, for the Sapajus genus; and 3) validate the experimental protocol of fecal hormones extraction and dosage. For the first two objectives, measures of fecal glucocorticoids metabolites, behavioral and environmental data of two wild populations of capuchin monkeys were taken. One in the Carlos Botelho State Park/São Paulo (PECB) and the other in Boa Vistas Farm/Piauí (FBV). For the experimental protocol validation an ACTH and dexamethasone challenge was executed with captive capuchin monkeys. Generalized Linear Mixed Models (MLGM) analysis showed a significant difference between basal levels of MFGs of the two populations, being the FBV the one with higher values. For that population there was also an effect of fruit availability in the habitat, frequency of encounters with other animals species and copulations in the mensal variation of the MFGs basal levels. There was no significant effect of the studied variables in the mensal basal levels variation of MFGs in the PECB population. The individual analyses showed that agonistic interactions among group members were the major cause of MFGs\' peaks in the studied subjects. Other major factors were females in proceptive period and copulations, that caused peaks not only in adult males, but also in juvenile males and the females themselves. The ACTH and dexamethasone challenge results validated the experimental protocol of hormones extraction and dosage. The obtained results are in agreement with previous researches that reveled marked differences in the social system of the two populations, specially in females social relationships that varied in accordance with the two areas ecological differences. The results also suggested that it is not possible to define reference values of MFGs\' basal levels for the Sapajus genus once the two populations are significantly different in this aspect. This work is just the beginning of a long endeavor to comprehend stress in wild capuchin monkeys, nevertheless it presents the first glimpse to the understanding of the natural stressors for those animals and how they impact the MFGs\' levels
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Barra, Cristina Botelho. "Determinação do valor de referência para o cortisol basal sérico em população pediátrica sem doença adrenal." Universidade Federal de Minas Gerais, 2012. http://hdl.handle.net/1843/BUOS-8UAQPC.
Full textAbstract:
The basal cortisol measurement reflects the hypothalamic-pituitary-adrenal activity. It is used in assessing the integrity of the axis response, mainly in patients undergoing long periods of glucocorticoid treatment, because they have a higher chance of adrenal suppression. In pediatrics, adrenal suppression should always be considered in children who received supraphysiologic glucocorticoid doses for more than two weeks. Under these conditions, there is an increased risk of adrenal crisis, even in the presence of moderate stressors. The cortisol values below the reference range are suggestive of adrenal dysfunction. Therefore, this evaluation may be crucial in the decision-making process. The same reference values of normal serum cortisol have been used, in practice, for adults and children. However, results obtained from an adult population may not be suitable for pediatric patients and can negatively impact the quality of this evaluation in childhood. Thus, the main objective of this study was to contribute to the assessment of basal cortisol levels in pediatric subjects. The assay method used by the reference laboratory for serum cortisol was the chemiluminescent enzyme immunoassay. The series was based on 120 reference individuals from 4-19 years old. The results obtained for cortisol were correlated with gender, age and pubertal maturation. The cortisol results profile was also studied for 95 children and adolescents from 0-19 years old, healthy or with persistent asthma and wheezing, prior to inhalation therapy. In the study, baseline serum cortisol increased with age and pubertal maturation. Serum cortisol showed no differences based on gender. Children from 0-3 years old with asthma and wheezing showed a great range of cortisol values, whereas older children showed less variation. The positive correlation between age and serum cortisol was observed only in children older than 3 years and it was more evident after 5 years old. Adolescents who were 16 to 19 years old had higher serum cortisol values than younger ones and also than those with incomplete pubertal development. The reference limits (2.5 and 97.5 percentiles) for the basal serum cortisol in the population of healthy subjects were: 2.97 g/dL [90% CI (1.44, 3.69)] and 23.4 g/dL [90% CI (16.3, 24.6)]. Thus, the interval for baseline serum cortisol of 4.46 to 22.7 g/dL being used up until now by the reference service was considered inappropriate for the pediatric population under study. The results presented here and the literature research suggest that reference intervals for serum cortisol should be determined specifically to the pediatric population.A medida do cortisol basal reflete a atividade hipotalâmica-hipofisária-adrenal. É utilizada na avaliação da integridade da resposta do eixo, principalmente em pacientes submetidos a longos períodos de tratamento glicocorticoide, por apresentarem maior risco de supressão adrenal. Em pediatria, a supressão adrenal deve ser sempre considerada em crianças que receberam doses suprafisiológicas de glicocorticoides por mais de duas semanas. Nessas condições, há risco de crise adrenal mesmo em vigência de agentes estressores moderados. Os valores de cortisol obtidos abaixo do intervalo de referência são sugestivos de disfunção adrenal. Sendo assim, a dosagem do cortisol basal pode ser crucial no processo de tomada de decisão. Os mesmos valores de referência de normalidade do cortisol basal sérico para adultos e crianças têm sido utilizados na prática. Contudo, resultados obtidos a partir de uma população adulta podem não ser adequados para a faixa etária pediátrica, comprometendo a qualidade das avaliações feitas na infância. Dessa forma, o objetivo principal do presente estudo é contribuir para essa adequação. Os valores de referência para o cortisol basal sérico foram determinados para indivíduos da faixa etária pediátrica. O método utilizado para a dosagem do cortisol pelo laboratório de referência foi o imunoensaio enzimático quimioluminescente. A casuística foi fundamentada em 120 indivíduos de referência de 4-19 anos. Os resultados obtidos para o cortisol foram correlacionados com o gênero, idade e grau de maturação sexual. O perfil de variações do cortisol basal também foi estudado em 95 crianças e adolescentes de 0-19 anos saudáveis ou com asma persistente e síndromes sibilantes, previamente à terapia inalatória. Na casuística, o cortisol basal sérico aumentou com a idade e com a maturação sexual e não apresentou diferenças baseadas no gênero. Crianças com asma ou síndromes sibilantes de 0-3 anos apresentaram grande amplitude de valores de cortisol, conquanto crianças mais velhas apresentaram menor variação. A correlação positiva entre idade e cortisol sérico foi observada apenas após os 3 anos, sendo mais expressiva após os 5 anos. Adolescentes de 16 a 19 anos apresentaram valores de ortisol sérico mais elevados que indivíduos mais jovens e com desenvolvimento sexual incompleto. Os limites de referência (percentis 2,5 e 97,5) para o cortisol basal sérico na população de indivíduos saudáveis foram: 2,97 g/dL [IC 90% (1,44; 3,69)] e 23,4 g/dL [IC 90% (16,3; 24,6)]. Dessa forma, o intervalo para o cortisol basal sérico de 4,46-22,7 g/dL,utililizado até o momento no serviço de referência, foi considerado inadequado para a população pediátrica em estudo. Os resultados apresentados e a experiência na literatura sugerem que intervalos de referência para o cortisol sérico, específicos para a população pediátrica, devem ser determinados.
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Chellew, Gálvez Karin. "The effect of progressive muscle relaxation in the basal cortisol response of high and low neurocitism students." Doctoral thesis, Universitat de les Illes Balears, 2015. http://hdl.handle.net/10803/291561.
Full textAbstract:
Els trets de personalitat juguen un paper rellevant en les diferències individuals en la secreció
del cortisol. No obstant això, la naturalesa i els mecanismes subjacents d'aquesta relació tot i
romanen poc clars. El cortisol, producte final de l'eix Hipotàlem-pituïtari-Adrenal (HPA), és un
glucocorticoide que el nostre cos secreta naturalment seguint un pronunciat cicle diürn, amb
nivells elevats davant de situacions particularment estressants (reactivitat del cortisol). La
present tesi doctoral té com a objectiu elucidar com els trets de personalitat influeixen en la
resposta del cortisol d'estudiants universitaris en tres condicions diferents: estressant, basal i
de relaxació. Aquest treball comença avaluant la resposta del cortisol davant d'una situació
estressant (parlar en públic) en estudiants de psicologia. Esperàvem que la reactivitat del
cortisol estigués positivament relacionada amb Obertura, Amabilitat i Responsabilitat, i
negativament amb Extraversió, Neuroticisme i Psicoticisme. En el nostre segon estudi,
avaluem el perfil de secreció de cortisol basal en estudiants universitaris amb puntuacions
extremes en Neuroticisme (N) tractant de demostrar una associació teòrica esperat entre N i la
secreció de cortisol diürn. Pensàvem que participants amb puntuacions altes en N exhibirien
constantment nivells elevats de cortisol diürn basal comparat amb aquells amb puntuacions
baixes en N. Finalment, volíem examinar si una setmana de Relaxació Muscular Progressiva
Abreujada (APMR) era eficaç per reduir nivells totals d'estrès psicològic i fisiològic de
participants amb puntuacions extremes en N. Els nostres resultats confirmen, en primer lloc,
que parlar en públic augmenta significativament la secreció de cortisol en comparació amb una
activitat acadèmica no estressant. A més a més, Responsabilitat ha estat associada amb un
augment significatiu dels nivells de cortisol, i Psicoticisme amb una a la baixa. En segon lloc,
trobem que Neuroticisme ha estat associat amb una elevada secreció de cortisol davant de
situacions d'estrès diari, encara que només després dels primers 45 min. després de despertar
(CAR). Aquesta associació ha estat independent del gènere i edat dels participants, si
fumaven o no, l'hora de despertar, o del dia de l'estudi. Finalment, en tercer lloc, APMR és una
eina eficaç per disminuir tant l'estrès psicològic com fisiològic en tots els participants,
independentment de puntuacions altes o baixes en Neuroticisme, el gènere, o l'edat dels participants.Los rasgos de personalidad juegan un papel relevante en las diferencias individuales en la secreción del cortisol. Sin embargo, la naturaleza y los mecanismos subyacentes a esta relación aún permanecen poco claros. El cortisol, producto final del eje Hipotálamo-Pituitario- Adrenal (HPA), es un glucocorticoide que nuestro cuerpo secreta naturalmente de acuerdo a un ciclo diurno pronunciado, con niveles elevados ante situaciones estresantes (reactividad del cortisol). El objetivo de la presente tesis doctoral ha sido elucidar cómo los rasgos de personalidad influyen en la respuesta del cortisol de estudiantes universitarios en tres condiciones distintas: estresante, basal y de relajación. Este trabajo comienza evaluando la respuesta del cortisol ante una situación estresante (hablar en público) en estudiantes de psicología. Esperábamos que la reactividad del cortisol estuviera positivamente relacionada con Apertura, Amabilidad y Responsabilidad, y negativamente con Extraversión, Neuroticismo y Psicoticismo. En nuestro segundo estudio, evaluamos el perfil de secreción de cortisol basal en estudiantes universitarios con puntuaciones extremas en Neuroticismo (N). Con ello pretendíamos demostrar de forma experimental una asociación planteada a nivel teórico entre N y secreción de cortisol diurno. Así esperábamos que los participantes con puntuaciones altas en N exhibieran niveles elevados de cortisol diurno basal comparado con participantes con puntuaciones bajas en este rasgo. Por último, queríamos examinar si una semana de Relajación Muscular Progresiva Abreviada (APMR) era efectiva en reducir los niveles totales de estrés psicológico y fisiológico de participantes con puntuaciones extremas en N. Nuestros resultados confirman, en primer lugar, que hablar en público aumenta significativamente la secreción de cortisol en comparación con una actividad académica no estresante. Además, Responsabilidad se asoció con un aumento significativo de la respuesta de cortisol, y Psicoticismo con una respuesta a la baja. En segundo lugar, encontramos que altos niveles de Neuroticismo se asociaron con una secreción elevada de cortisol en situaciones de estrés diario, aunque solo después de los primeros 45 min después de despertar (CAR). Esta asociación fue independiente del género y edad de los participantes, si fumaban o no, de la hora de despertar, o del día del estudio. Por último, en tercer lugar, APMR fue eficaz en disminuir tanto el estrés psicológico como fisiológico en todos los participantes, independientemente del género, la edad o de la puntuación de Neuroticismo de los participantes.
Personality traits play a significant role in individual differences in cortisol response (LeBlanc, Ducharme, & Thompson, 2004). However, the nature and underlying mechanisms of the relationship between cortisol secretion and personality traits still remain unclear. Cortisol, an end product of the Hypothalamic-Pituitary-Adrenal axis (HPA), is a glucocorticoid that our body naturally secretes according to a pronounced diurnal cycle with increased values under stressful situations (cortisol reactivity). The aim of the present PhD dissertation was to elucidate how personality traits influence the cortisol secretion of undergraduate students in three different conditions; stressful, baseline, and relaxation. This work began by evaluating the cortisol response facing a stressful situation (public speaking) of psychology students. We believed that cortisol reactivity would be positively related to Openness, Agreeableness, and Conscientiousness, and negatively to Extraversion, Neuroticism and Psychoticism. In our second study, we assessed the baseline cortisol in students with extreme scores in Neuroticism (N) attempting to prove a theoretical expected association between N and diurnal cortisol secretion. We postulated that high N participants would display elevated diurnal background levels of cortisol compared to low N participants. Finally, we examined whether one week of Abbreviated Progressive Muscle Relaxation (APMR) was effective in reducing overall levels of psychological and physiological stress of high- and low-N participants. Our results confirmed, firstly, that public speaking significantly increased cortisol secretion when compared to a non-stressful academic activity. In addition, Conscientiousness was associated with an enhanced cortisol response to public speaking, and Psychoticism with a blunted one. Secondly, we found that high levels of Neuroticism were associated with elevated cortisol secretion on daily stress, but only after the first 45 min following awakening (CAR). This association was independent of sex and age, smoking status, awakening time, and day of study. Finally, in third place, APMR was effective in decreasing both psychological and physiological stress in all participants independently of their N-score, gender, or age.
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Strahler, Jana. "Salivary alpha-amylase: More than an enzyme Investigating confounders of stress-induced and basal amylase activity." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-60778.
Full textAbstract:
Summary: Salivary alpha-amylase: More than an enzyme - Investigating confounders of stress-induced and basal amylase activity (Dipl.-Psych. Jana Strahler)
The hypothalamus-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) are two of the major systems playing a role in the adaptation of organisms to developmental changes that threaten homeostasis. The HPA system involves the secretion of glucocorticoids, including cortisol, into the circulatory system. Numerous studies have been published that introduced salivary cortisol to assess HPA axis activity and therefore strengthens its role as an easy obtainable biomarker in stress research that can be monitored easily and frequently. Recent findings suggest a possible surrogate marker of autonomic activity due to autonomic innervation of salivary glands: salivary alpha-amylase (sAA). Up to date, additional methodological research is needed for a better understanding of the advantages and disadvantages of sAA activity in comparison to already established markers of ANS activity. The aim of the present thesis is to further our knowledge of confounders of sAA activity under basal and acute stress conditions and to strengthen the validity of this enzyme as an easy obtainable alternative for ANS testing.
After introducing classical and modern stress concepts and stress system physiology (chapter 2), the reader is acquainted with anatomical basics of salivary gland innervation and secretion of salivary proteins, including sAA, due to autonomic innervation (chapter 3 and 4). Afterwards, a more nuanced review of methodological considerations of sAA determination shows gaps of knowledge concerning its usefulness as a marker of ANS activity (chapter 5). Given the fact that the integration of sAA into developmental and aging research is a relative recent phenomenon, several issues have to be addressed before a final conclusion could be drawn. Therefore, we conducted a series of studies incorporating these considerations regarding behavioral correlates of inter- and intraindividual differences in sAA activity with a special emphasis on older adults.
Chapter 7 deals with sAA activity under psychological stress conditions in different age groups. Since vulnerability to disease and disease prevalence patterns change with age, it is important to investigate stress reactivity of people in different age groups. We therefore investigated children between 6 and 10 years, because childhood is a sensitive period of growth and development, and thus plays an important role for later life health. Young adults were included to represent the most studied human age group as a reference. Older adults between 59 and 61 years were investigated, because at this age the course is set for the further development of a person’s health in later life, and because autonomic stress responses in older age might be important determinants of cardiovascular and inflammatory aging. Our goal is to test for associations of sAA with more established stress system markers, i.e., salivary cortisol as outcome measurement of HPA reactivity, heart rate (HR) and heart rate variability (HRV) as markers for autonomic reactivity, and to directly compare these responses between different age groups across the life span. Secretion of sAA and cortisol was repeatedly assessed in 62 children, 78 young adults, and 74 older adults after exposure to a standardized psychosocial stressor, the Trier Social Stress Test. In addition, cardiovascular activity was measured in both adult groups. Older adults showed attenuated sAA, HR, and HRV responses. Furthermore, we found higher sAA but lower cortisol at baseline as well as lower sAA and cortisol responses in children. Age by sex interactions were observed only for cortisol with higher responses in older male participants. No associations between the parameters were found. Results in children and young adults confirm previous results. Overall, findings implicate sAA as an alternative or additional autonomic stress marker throughout the life span, with marked and rapid responsiveness to stress in three relevant age groups.
The impact of age and chronic stress on basal sAA activity is the center of interest in chapter 8. We therefore assessed diurnal profiles of sAA and salivary cortisol in 27 younger and 31 older competitive ballroom dancers as well as 26 younger and 33 older age- and sex-matched controls. According to the Allostatic Load concept, repeated, non-habituating responses to social-evaluative conditions, which characterize the lives of competitive ballroom dancers, should be associated with stress system dysregulations. Furthermore, we expect to see an increased sympathetic drive associated higher overall alpha-amylase activity in older adults. Analyses revealed an elevated daily overall output of sAA in older adults while there was no effect of age on mean cortisol levels. Alterations of diurnal rhythms were only seen in younger male dancers showing a flattened diurnal profile of sAA and younger dancers and female older dancers showing a blunted diurnal rhythmicity of cortisol. Furthermore, we found a negative correlation between summary indices of basal sAA and the amount of physical activity. In conclusion, higher overall output of sAA in older adults was in line with the phenomenon of a “sympathetic overdrive” with increasing age. Furthermore, a lower output of sAA in people who are more physical active was in line with the hypothesis of an exercise-induced decrease of sympathetic activity.
Taken together, results of chapter 7 and 8 show a clear impact of age on sAA activity, either under acute stress or basal conditions. One problem when integrating sAA into developmental and aging research is the use of adrenergic agonists and antagonists what is very common in older adults, i.e. antihypertensive drugs (AD). As well, the previously shown sympathetic overactivity that occurs with normal aging is associated with higher blood pressure (BP). Therefore, chapter 9 deals with a possible impact of high BP and AD on diurnal sAA activity in 79 older adults (33 normotensive adults, 16 medicated vs. 45 hypertensive adults, 34 medicated). Results showed a pronounced rhythm of sAA in all groups. Diurnal profiles differed significantly between men and women with men lacking the typical decrease of sAA in the morning and showing more pronounced alterations throughout the day. An effect of AD on sAA profiles and area under the curve values indicates that subjects not using AD´s show a heightened diurnal profile and a higher total output of sAA. Descriptively, this was also true for hypertensive older adults. Hypertensive subjects and those not using AD showed the highest diurnal output of sAA and the steepest slope. In sum, our results show an impact of antihypertensive medication and a difference between normotensive and hypertensive subjects on characteristics of diurnal sAA activity. Hence, findings are of particular interest in research using sAA as a prognostic indicator of pathological states and processes.
Given the fact that hypertension was also shown to be associated with substantial changes of transmitters within the suprachiasmatic nucleus (SCN) - the “biological clock” that receives photic input from retinal glands via the retinohypothalamic pathway - and an altered output from the SCN to the sympathetic nervous system, we broaden the idea of a possible effect of different lighting conditions on morning sAA profiles in chapter 10. In a counterbalanced within-subjects design six men and 16 women of different ages collected sAA morning profiles on two consecutive days with leaving their shutters closed on the one day (= dark) and open their shutters on the other day (= bright). We were able to replicate earlier findings of light-induced changes of salivary cortisol with higher responses during the bright condition. On either day, women showed larger cortisol increases than men. Despite multisynaptic autonomic connections arising from the SCN projecting to multiple organs of the body, we could not find an effect of sunlight on sAA morning profiles. Evidence for circadian clock gene expression in human oral mucosa might account for this result and indicates that peripheral oscillators may act more like integrators of multiple different time cues, e.g. light, food intake, instead of a “master” oscillator (SCN).
Results of chapter 7 to 10 provide clear evidence that sAA is heightened in states of autonomic arousal, i.e. stress, aging and hypertension, and that its circadian rhythmicity seems to be regulated rather integrative than directly via efferent input from hypothalamic SCN neurons. In chapter 11 this thesis tries to approach one central question: What is the biological meaning of the findings made? According to this enzyme´s anti-bacterial and digestive action short term changes might not have a biological meaning itself but rather reflect just a small part of multiple coordinated body responses to stressful stimuli. While the sympathetic branch of the ANS mainly stimulates protein secretion, the parasympathetic branch stimulates saliva flow. Acute stress responses might therefore be interpreted as reflecting predominant sympathetic activity together with parasympathetic withdrawal. The same mechanism could also be suitable for the finding of higher diurnal levels of sAA in older adults or hypertensive subjects reflecting a higher peripheral sympathetic tone in these groups. Diurnal profiles of sAA itself may reflect circadian changes in autonomic balance. Circadian rhythms are of great advantage since they enable individuals to anticipate. This pre-adaptation enables the individual to cope with upcoming demands and challenges. Our finding of a relationship between sAA and salivary cortisol what strengthens the relevance of glucocorticoids that were previously shown to be able to phase shift circadian rhythms in cells and tissue. Within a food-related context there is evidence that decreasing levels of sAA in the morning could reflect increases of feeling hungry since sAA systematically increases during food consumption and with the subjective state of satiety. So far, much more research is needed to identify underlying physiological mechanisms of circadian sAA rhythmicity.
Taking the next step, future studies will have to focus on the integration of sAA assessment into longitudinal studies and different disease states to prove its applicability as a marker of sympathetic neural functioning in the genesis and prognosis of disease.
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Wuethrich, Stephanie Nadya. "The modulatory role of morning and afternoon basal cortisol levels on neural activation changes in healthy young males performing an n-back working memory task : an exploratory fMRI study." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101808.
Full textAbstract:
Human cognitive processes, such as learning and memory, are particularly vulnerable to the effects of cortisol, the human stress hormone. In the field of magnetic resonance imaging (MRI) the different cortisol characteristics are neither controlled nor accounted for. This study will aim to investigate, by means of functional MRI, the effects of morning and afternoon cortisol levels on neural activation changes in response to a working memory task in young males. We hypothesized a significant difference between morning and afternoon subjects' cortisol levels and neural activation patterns in relation to the task. Nineteen young males were recruited, 9 for the morning group and 10 for the afternoon group. Cortisol levels, neuronal activation, and behavioural measurements (correct percentage of hits and reaction time) were assessed during the task. Six saliva samples were taken during the experiment at various time intervals. As expected, morning cortisol levels were higher than afternoon cortisol levels. Results indicate that the afternoon group had significantly slower reaction time on the frontal task compared to the morning group, whilst the percentage of correct hits did not differ. Furthermore, we observed an increased range of neural activation in the morning group compared to the afternoon group. This study demonstrates the impact of time of day of testing (i.e. different cortical levels) on neural activation in functional MRI experiments. It is important for investigators using this technique to be aware of and control for this variable.
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Hutton, Elizabeth Anne May. "Somatosensory cortical input to the basal ganglia." Thesis, University of Edinburgh, 1998. http://webex.lib.ed.ac.uk/abstracts/hutton01.pdf.
Full textBooks on the topic "Basal Cortisol"
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Kimura, Minoru, and Ann M. Graybiel, eds. Functions of the Cortico-Basal Ganglia Loop. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0.
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Mason, Peggy. Basal Ganglia. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190237493.003.0025.
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The core function of the basal ganglia is action selection, the process of choosing between mutually exclusive actions. Under baseline or default conditions, the basal ganglia suppress movement and prevent more than one movement from occurring simultaneously. The importance of chunking and operational learning is explored through exemplary typing tasks. Pathways through the basal ganglia employ the same input and output ports. Inputs far outnumber outputs from the basal ganglia. Subcortical loops through the basal ganglia are more effective than are cortical loops. The functions of the hyperdirect, direct and indirect pathways to motor control in the skeletomotor loop are detailed. Hemiballismus, Parkinson’s disease, and Huntington’s disease are key basal ganglia disorders. The use of deep brain stimulation (DBS) of the subthalamic nucleus as a treatment for Parkinson’s disease is discussed. Finally, additional basal ganglia loops such as the oculomotor loop are introduced.
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Guillery, Ray. The subcortical motor centres. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198806738.003.0004.
Full textAbstract:
This chapter looks more closely at some of the subcortical motor centres that play a peripheral or an auxiliary role in the standard view: primarily the basal ganglia, the cerebellum, and the superior colliculus; also several brainstem centres. These all play a significant role in motor control and between them receive inputs from the majority of cortical areas. The colliculus serves as an example of a centre that in mammals is often dominated by the cortex. The cortical action may be direct or may involve a strong inhibitory pathway through the basal ganglia. The standard view assigns even quite simple actions to the motor cortex, although comparable actions can be controlled in our vertebrate ancestors by the midbrain tectum which corresponds to the mammalian superior and inferior colliculi. The interactive view has information about movements going to most parts of the cortex, and has all cortical areas contributing to motor control through phylogenetically old centres. For most cortical areas, we must still learn how their motor outputs influence our actions.
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de Bie, Robertus M. A., and Susanne E. M. Ten Holter. “My Arm Is Not Working”. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190607555.003.0011.
Full textAbstract:
Corticobasal syndrome is a clinical diagnosis based on the presence of one or more movement disorders suggestive of basal ganglia dysfunction, typically asymmetrical, with evidence of associated cortical dysfunction. This is a pathologically heterogeneous group of disorders that can share a common phenotype. Corticobasal degeneration is one of these pathologies, representing one of the rarest forms of atypical parkinsonism. When confronted with a patient with higher cortical dysfunction, specific assessment for apraxia, cortical sensory loss, and cognition is indicated. Corticobasal syndrome is currently untreatable, regardless of the nature of the underlying pathology, and in most cases progression is fast with significant disability that is typically unresponsive to levodopa.
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Jones, Barbara E. Neuroanatomical, neurochemical, and neurophysiological bases of waking and sleeping. Edited by Sudhansu Chokroverty, Luigi Ferini-Strambi, and Christopher Kennard. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199682003.003.0004.
Full textAbstract:
Neurons distributed through the reticular core of the brainstem, hypothalamus, and basal forebrain and giving rise to ascending projections to the cortex or descending projections to the spinal cord promote the changes in cortical activity and behavior that underlie the sleep–wake cycle and three states of waking, NREM (slow wave) sleep, and REM (paradoxical) sleep. Forming the basic units of these systems, glutamate and GABA cell groups are heterogeneous in discharge profiles and projections, such that different subgroups can promote cortical activation (wake/REM(PS)-active) versus cortical deactivation (NREM(SWS)-active) by ascending influences or behavioral arousal with muscle tone (wake-active) versus behavioral quiescence with muscle atonia (NREM/REM(PS)-active) by descending influences. These different groups are in turn regulated by neuromodulatory systems, including cortical activation (wake/REM(PS)-active acetylcholine neurons), behavioral arousal (wake-active noradrenaline, histamine, serotonin, and orexin neurons), and behavioral quiescence (NREM/REM(PS)-active MCH neurons). By different projections, chemical neurotransmitters and discharge profiles, distinct cell groups thus act and interact to promote cyclic oscillations in cortical activity and behavior forming the sleep-wake cycle and states.
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Steele, Vaughn R., Vani Pariyadath, Rita Z. Goldstein, and Elliot A. Stein. Reward Circuitry and Drug Addiction. Edited by Dennis S. Charney, Eric J. Nestler, Pamela Sklar, and Joseph D. Buxbaum. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190681425.003.0044.
Full textAbstract:
Addiction is a complex neuropsychiatric syndrome related to dysregulation of brain systems including the mesocorticolimbic dopamine reward circuit. Dysregulation of reward circuitry is related to each of the three cyclical stages in the disease model of addiction: maintenance, abstinence, and relapse. Parsing reward circuitry is confounded due to the anatomical complexity of cortico-basal ganglia-thalamocortical loops, forward and backward projections within the circuit, and interactions between neurotransmitter systems. We begin by introducing the neurobiology of the reward system, specifically highlighting nodes of the circuit beyond the basal ganglia, followed by a review of the current literature on reward circuitry dysregulation in addiction. Finally, we discuss biomarkers of addiction identified with neuroimaging that could help guide neuroprediction models and development of targets for effective new interventions, such as noninvasive brain stimulation. The neurocircuitry of reward, especially non-prototypical nodes, may hold essential keys to understanding and treating addiction.
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Montgomery, Erwin B. Pathophysiological Mechanisms. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190259600.003.0008.
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Pathophysiology is central to neuroscience and psychiatry for a number of reasons. Indeed, nearly every inference to normal function of the nervous system is derived from notions of pathophysiology. Understanding DBS’s mechanisms of action—a therapeutic mechanism, particularly—greatly depends on the prior informing conception of pathophysiology. Several current theories of pathophysiology are critically reviewed such as the GPi Rate, high beta oscillations, excessive bursting and hypersynchronization theories. A novel theory offered that introduces the concept of the basal ganglia-thalamic-cortical system as a network of loosely coupled nonlinear polysynaptic reentrant oscillators.
Book chapters on the topic "Basal Cortisol"
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Steenbergen, Peter J., Juriaan R. Metz, Gert Flik, Michael K. Richardson, and Danielle L. Champagne. "Methods to Quantify Basal and Stress-Induced Cortisol Response in Larval Zebrafish." In Neuromethods, 121–41. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-61779-597-8_9.
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Miller, Mark W., Erika J. Wolf, Laura Fabricant, and Nathan Stein. "Low Basal Cortisol and Startle Responding as Possible Biomarkers of PTSD: The Influence of Internalizing and Externalizing Comorbidity." In Post-Traumatic Stress Disorder, 277–93. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60327-329-9_13.
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Strick, Peter L., Richard P. Dum, and Hajime Mushiake. "Basal Ganglia ‘Loops’ with the Cerebral Cortex." In Functions of the Cortico-Basal Ganglia Loop, 106–24. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_7.
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Kimura, Minoru, and Ann M. Graybiel. "Role of Basal Ganglia in Sensory Motor Association Learning." In Functions of the Cortico-Basal Ganglia Loop, 2–17. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_1.
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Tanji, Jun, Keisetsu Shima, Yoshiya Matsuzaka, and Ulrike Halsband. "Neuronal Activity in the Supplementary, Presupplementary, and Premotor Cortex of Monkey." In Functions of the Cortico-Basal Ganglia Loop, 154–65. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_10.
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Sawaguchi, Toshiyuki. "The Role of Dopamine in Frontal Motor Cortical Functions of Monkeys." In Functions of the Cortico-Basal Ganglia Loop, 166–88. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_11.
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Ohye, Chihiro. "Activity of the Pallidal Neurons Related to Voluntary and Involuntary Movements in Humans." In Functions of the Cortico-Basal Ganglia Loop, 190–200. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_12.
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Yanagisawa, Nobuo, and Fuyuhiko Tamaru. "Mechanisms of Bradykinesia—Disturbances in Sensorimotor Processing." In Functions of the Cortico-Basal Ganglia Loop, 201–13. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_13.
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Hikosaka, Okihide, Miya Kato Rand, Shigehiro Miyachi, and Kae Miyashita. "Procedural Learning in the Monkey." In Functions of the Cortico-Basal Ganglia Loop, 18–30. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_2.
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Schultz, Wolfram. "The Primate Basal Ganglia Between the Intention and Outcome of Action." In Functions of the Cortico-Basal Ganglia Loop, 31–48. Tokyo: Springer Japan, 1995. http://dx.doi.org/10.1007/978-4-431-68547-0_3.
Full textConference papers on the topic "Basal Cortisol"
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"Respuesta al estrés quirúrgico: Gasto metabólico basal, cortisol y glucemia. Tratamiento perioperatorio." In Resúmenes de trabajos libres congreso CLASA 2019. Sociedad de Anestesiología de Chile, 2019. http://dx.doi.org/10.25237/congresoclasa2019.88.
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Gilmour, Timothy P., Constantino Lagoa, W. Kenneth Jenkins, Anand N. Rao, Matthew A. Berk, Kala Venkiteswaran, and Thyagarajan Subramanian. "Transfer entropy between cortical and basal ganglia electrophysiology." In 2012 IEEE Signal Processing in Medicine and Biology Symposium (SPMB). IEEE, 2012. http://dx.doi.org/10.1109/spmb.2012.6469453.
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Debnath, Shoubhik, and John Nassour. "Extending cortical-basal inspired reinforcement learning model with success-failure experience." In 2014 Joint IEEE International Conferences on Development and Learning and Epigenetic Robotics (ICDL-Epirob). IEEE, 2014. http://dx.doi.org/10.1109/devlrn.2014.6982996.
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Su, Fei, Jiang Wang, Bin Deng, and Huiyan Li. "Effects of deep brain stimulation amplitude on the basal-ganglia-thalamo-cortical network." In 2015 27th Chinese Control and Decision Conference (CCDC). IEEE, 2015. http://dx.doi.org/10.1109/ccdc.2015.7162632.
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Yen, Yu-yang, Lee-ray Chen, Ying-zu Huang, and Chung-Chuan Lo. "Models of cortico-basal ganglia circuits and synaptic plasticity for transcranial magnetic stimulation." In 2012 ICME International Conference on Complex Medical Engineering (CME). IEEE, 2012. http://dx.doi.org/10.1109/iccme.2012.6275678.
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Fountas, Zafeirios, and Murray Shanahan. "Phase offset between slow oscillatory cortical inputs influences competition in a model of the basal ganglia." In 2014 International Joint Conference on Neural Networks (IJCNN). IEEE, 2014. http://dx.doi.org/10.1109/ijcnn.2014.6889687.
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Dunn, Eleanor M., and Madeleine M. Lowery. "A model of the cortico-basal ganglia network and local field potential during deep brain stimulation." In 2015 7th International IEEE/EMBS Conference on Neural Engineering (NER). IEEE, 2015. http://dx.doi.org/10.1109/ner.2015.7146756.
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Fleming, John E., and Madeleine M. Lowery. "Changes in Neuronal Entropy in a Network Model of the Cortico-Basal Ganglia during Deep Brain Stimulation." In 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC). IEEE, 2019. http://dx.doi.org/10.1109/embc.2019.8857440.
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Schmidt, Christian, Eleanor Dunn, Madeleine Lowery, and Ursula van Rienen. "Simulating the therapeutic effects of deep brain stimulation in rodents using a cortico-basal ganglia network and volume conductor model." In 2015 7th International IEEE/EMBS Conference on Neural Engineering (NER). IEEE, 2015. http://dx.doi.org/10.1109/ner.2015.7146757.
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