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Prenatal Exposure to Perfluoroalkyl Acids and Serum Testosterone Concentrations at 15 Years of Age in Female ALSPAC Study ParticipantsMaisonet, Mildred, Calafat, Antonia M., Marcus, Michele, Jaakkola, Jouni J.K., Lashen, Hany 01 December 2015 (has links)
Background: Exposure to perfluorooctane sulfonic acid (PFOS) or to perfluorooctanoic acid (PFOA) increases mouse and human peroxisome proliferator–activated receptor alpha (PPARα) subtype activity, which influences lipid metabolism. Because cholesterol is the substrate from which testosterone is synthesized, exposure to these substances has the potential to alter testosterone concentrations.
Objectives: We explored associations of total testosterone and sex hormone–binding globulin (SHBG) concentrations at age 15 years with prenatal exposures to PFOS, PFOA, perfluorohexane sulfonic acid (PFHxS), and perfluoronanoic acid (PFNA) in females.
Methods: Prenatal concentrations of the perfluoroalkyl acids (PFAAs) were measured in serum collected from pregnant mothers at enrollment (1991–1992) in the Avon Longitudinal Study of Parents and Children (ALSPAC). The median gestational age when the maternal blood sample was obtained was 16 weeks (interquartile range, 11–28 weeks). Total testosterone and SHBG concentrations were measured in serum obtained from their daughters at 15 years of age. Associations between prenatal PFAAs concentrations and reproductive outcomes were estimated using linear regression models (n = 72).
Results: Adjusted total testosterone concentrations were on average 0.18-nmol/L (95% CI: 0.01, 0.35) higher in daughters with prenatal PFOS in the upper concentration tertile compared with daughters with prenatal PFOS in the lower tertile. Adjusted total testosterone concentrations were also higher in daughters with prenatal concentrations of PFOA (β = 0.24; 95% CI: 0.05, 0.43) and PFHxS (β = 0.18; 95% CI: 0.00, 0.35) in the upper tertile compared with daughters with concentrations in the lower tertile. We did not find evidence of associations between PFNA and total testosterone or between any of the PFAAs and SHBG.
Conclusions: Our findings were based on a small study sample and should be interpreted with caution. However, they suggest that prenatal exposure to some PFAAs may alter testosterone concentrations in females.
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MECHANISMS AND POTENTIAL THERAPY ON DISRUPTED BLOOD PRESSURE CIRCADIAN RHYTHM IN DIABETESHou, Tianfei 01 January 2018 (has links)
Arterial blood pressure (BP) undergoes a 24-hour oscillation that peaks in the active day and reaches a nadir at night during sleep in humans. Reduced nocturnal BP fall (also known as non-dipper) is the most common disruption of BP circadian rhythm and is associated with increased risk of untoward cardiovascular events and target organ injury. Up to 75% of diabetic patients are non-dippers. However, the mechanisms underlying diabetes associated non-dipping BP are largely unknown. To address this important question, we generated a novel diabetic db/db-mPer2Luc mouse model (db/db-mPer2Luc) that allows quantitatively measuring of mPER2 protein oscillation by real-time mPer2Luc bioluminescence monitoring in vitro and in vivo. Using this model, we demonstrated that the db/db-mPer2Luc mice have a diminished BP daily rhythm. The phase of the mPER2 daily oscillation is advanced to different extents in explanted peripheral tissues from the db/db-mPer2Luc mice relative to that in the control mice. However, no phase shift is found in the central oscillator, the suprachiasmatic nucleus (SCN). The results indicate that the desynchrony of mPER2 daily oscillation in the peripheral tissues contributes to the loss of BP daily oscillation in diabetes.
Extensive research over the past decades has been focused on how the components of food (what we eat) and the amount of food (how much we eat) affect metabolic diseases. Only recently has it become appreciated that the timing of food intake (when we eat), independent of total caloric and macronutrient quality, is also critical for metabolic health. To investigate the potential effect of the timing of food intake on the BP circadian rhythm, we simultaneously monitored the BP and food intake profiles in the diabetic db/db and control mice using radiotelemetry and BioDAQ systems. We found the loss of BP daily rhythm is associated with disrupted food intake rhythm in the db/db mice. In addition, the normal BP daily rhythm is altered in the healthy mice with abnormal feeding pattern, in which the food is available only during the inactive-phase. To explore whether imposing a normal food intake pattern is able to prevent and restore the disruption of BP circadian rhythm, we conducted active-time restricted feeding (ATRF) in the db/db mice. Strikingly, ATRF completely prevents and restorers the disrupted BP daily rhythm in the db/db mice. While multiple mechanisms likely contribute to the protection of ATRF on the BP daily rhythm, we found that ATRF improves the rhythms of energy metabolism, sleep-wake cycle, BP-regulatory hormones and autonomic nervous system (ANS) in the db/db mice. To further investigate the molecular mechanism by which ATRF regulates BP circadian rhythm, we determined the effect of ATRF on the mRNA expressions of core clock genes and clock target genes in the db/db mice. Of particular interest is that we found among all the genes we examined, the mRNA oscillation of Bmal1, a key core clock gene, is disrupted by diabetes and selectively restored by the ATRF in multiple peripheral tissues in the db/db mice. More importantly, we demonstrated that Bmal1 is partially required for ATRF to protect the BP circadian rhythm.
In summary, our findings indicate that the desynchrony of peripheral clocks contributes to the abnormal BP circadian pattern in diabetes. Moreover, our studies suggest ATRF as a novel and effective chronotherapy against the disruption of BP circadian rhythm in diabetes.
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Evaluation of the feasibility of intralymphatic injection of Diamyd®Fessehaye, Selam January 2019 (has links)
Type 1 diabetes affects a person’s life on many levels in terms of quality of life, health, and socioeconomic costs both for the patients but also their families. As of now there is no therapy that targets the underlying mechanism of the disease. Intralymphatic administration of Diamyd® is being evaluated in a phase IIb clinical trial, DIAGNODE-2. The aim was to examine if the intralymphatic administration is feasible for both patients and medical professionals, and to identify any aspects of the procedure that can be improved. This feasibility study is based on interviews and answers received from questionnaires. The medical professionals that were selected were radiologists and study nurses that are involved in the DIAGNODE-2 trial. The radiologists were the prime focus and were thus interviewed through face-to-face/skype or phone and answered a questionnaire. Study nurses, having more contact with the patient, answered a survey in order to gain additional insights into the patient perspective. The results show that the radiologists has a positive view towards the administration procedure, which was described as easy and safe. According to the study nurses the patients accept the procedure and they agreed that the patients understand the injection procedure once they received the information. In terms of the emotional state of the patients they were a bit nervous, but they became calmer after receiving the first injection. Based on the above-mentioned findings the intralymphatic injection procedure is described as feasible and has the potential to become a part of the standard clinical routine.
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Fibroblast growth factor-23 and Klotho in bone/mineral and parathyroid disordersKrajisnik, Tijana January 2009 (has links)
Fibroblast growth factor-23 (FGF23) is a novel, bone-produced hormone that regulates renal phosphate (Pi) reabsorption and calcitriol metabolism. Disorders of mineral and bone metabolism, such as autosomal dominant hypophosphatemic rickets (ADHR) and hyperostosis-hyperphosphatemia syndrome (HHS), witness the importance of well-balanced serum levels of FGF23. Patients with chronic kidney disease (CKD) are highly morbid due to Pi retention/hyperphosphatemia and calcitriol deficiency, which lead to elevated serum levels of parathyroid hormone (PTH) and secondary hyperparathyroidism (sHPT). As a response to hyperphosphatemia, CKD patients have also remarkably high serum FGF23 levels, which are associated with cardiovascular risk factors and increased mortality in CKD. The overall aim of this dissertation was to discern a possible role of FGF23 in parathyroid biology. Our in vitro experiments on isolated bovine parathyroid cells demonstrate that FGF23 directly and dose-dependently suppresses the PTH production and secretion, while increasing the expression of the 25-hydroxyvitamin D3-activating enzyme 1α-hydroxylase. We investigated possible expressional changes in the FGF23 receptor co-factor Klotho in hyperparathyroid disorders and found that Klotho expression is decreased or absent and inversely correlated to serum calcium (Ca) in adenomas of primary HPT (pHPT). In the hyperplastic parathyroid glands of sHPT, Klotho expression declines in parallel with the kidney function and correlates with the glomerular filtration rate. Moreover, Klotho expression is suppressed by Ca and FGF23, increased by calcitriol, but unaffected by Pi and PTH in vitro. Finally, we identified a novel missense mutation in the gene encoding GALNT3, which is normally involved in the post-translational glycosylation of FGF23, as the cause of aberrant FGF23 processing in a patient with HHS. In summary, we provide evidence for a novel bone/parathyroid axis in which FGF23 functions as a direct, negative regulator of the PTH production. High extracellular Ca is a major determinant of the Klotho expression in pHPT, whereas the Klotho levels in sHPT may be attributed to a combination of the high FGF23 and Ca, and low calcitriol levels associated with CKD. Hence, the decreased Klotho expression in sHPT could explain the concomitantly high FGF23 and PTH levels, as well as the failure of FGF23 to prevent or mitigate the development of sHPT in CKD.
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Behavioral effects of female sex steroid hormones : models of PMS and PMDD in Wistar ratsLöfgren, Magnus January 2009 (has links)
Background Animal models can be used to mimic human conditions of psychopathology, and also as pre-clinical models to evaluate candidate drugs. With hormonal treatment it is possible to produce behavior in the rat which corresponds to the mental symptoms of pre-menstrual syndrome (PMS), and pre-menstrual dysphoric disorder (PMDD). PMS affects 25-30 % of all women in fertile age and 3-8% are diagnosed with the more severe condition PMDD. The cardinal mental symptoms are; irritability, mood-swings, depression, anxiety, fatigue, insomnia, difficulties with concentration and memory and learning difficulties. The symptoms of PMS/PMDD occur in the luteal phase in conjunction with increasing concentrations of progesterone (P4) and P4-metabolites. In anovulatory cycles the symptoms are absent. The hormones which produce the monthly reoccurring negative symptoms on mood are foremost the neuroactive metabolites; allopregnanolone (ALLO) and tetrahydro-deoxycorticosterone (THDOC). ALLO is produced by the corpus luteum, but can also be synthesized in the brain, both ALLO and THDOC can also be released from the adrenal cortex during stress. These steroids are active on the inhibitory GABA neurotransmitter system through the GABAA receptor, and the effects are similar to that of alcohol and benzodiazepines. These steroids have strong sedative and hypnotic effects. A paradox is that some individuals seem to react with negative mood on sex steroids while all fertile women have the cyclical steroid changes during the menstrual cycle. Some individuals are more sensitive to neuroactive steroids with influences of personality, heritability and stress factors. Aims The thesis aims were to develop pre-clinical animal models of PMS/PMDD and to investigate induction of ALLO tolerance, individual sensitivity to neurosteroids and the interactions between chronic social stress and neurosteroids. Methods In these studies male and female Wistar rats were used to test steroid hormone effects on learning and memory and behaviors analogous to negative mood symptoms. This was accomplished through hormonal treatment and a subsequent withdrawal period from P4 (P4) + estradiol (E2) (PEWD), or ALLO. To assess tolerance, memory and learning in the Morris water maze (MWM) was studied. Anxiety-like behaviors were tested with the elevated plus maze (EPM), open field test (OFT), and the intruder test (IT). The EPM or OFT was used to classify the rats as high or low responders on risk-taking and explorative behavior (HR/LR). For social ranking order assessment the tube test (TT) and food competition test (FCT) were used. Chronic social stress was accomplished through co-habituation with two older rats (chronic subordination stress). In female rats the estrous cycle followed using staining of vaginal smears. Concentration of corticosterone (CORT) was measured by radio-immuno-assay (RIA). Results In the MWM ALLO pre-treatment produced tolerance to the acute negative ALLO effects. Both male and female rats showed behavioral correlations between the EPM and OFT tests, and correlations were also seen in CORT levels. Individuals with the stable trait of high risk-taking and explorative behavior (HR) were more sensitive to PEWD induction of anxiety-like behavior. These animals also showed decreased CORT levels during withdrawal. Chronic subordination stress enhanced the response to PEWD on measures of locomotor activity and social anxiety-like behavior. Conclusions It is possible to induce tolerance to the negative ALLO effects on learning and memory. The animal models of anxiety-like behavior show an individual PEWD response profile where HR rats are more sensitive. Exposure to chronic social stress enhanced the PEWD response. Hence there are both inherent and environmental factors behind the behavioral response to steroid hormones in rats. / Stress- och könshormoners verkningar på centrala nervsystemet
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Ovarian Reserve and Assisted ReproductionBrodin, Thomas January 2013 (has links)
Treatment success in IVF-ICSI is mainly limited by female age, but differences in ovarian reserve (OR; the remaining pool of oocytes and their quality) between individuals modify treatment prerequisites among women of similar age. OR may be assessed by OR tests (ORTs). The main aims of this work were to study menstrual cycle length (MCL), basal levels of circulating gonadotrophins, antral follicle count (AFC) and serum Anti-Müllerian hormone (AMH) levels and their associations with and prognostic capacities regarding IVF-ICSI outcome in large cohorts of unselected women. Age-adjusted MCL was positively and linearly associated with pregnancy rates (PRs), live-birth rates (LBRs) and ovarian response to controlled ovarian hyperstimulation. An MCL of >34 days almost doubled the LBR compared with an MCL of <26 days. The grouped variable ‘combined FSH and LH levels’ was superior to both individual gonadotrophin levels and the LH:FSH ratio. The highest mean PR was seen in connection with a combination of FSH <6.7 U/l with LH >4.9 U/l; PRs were lowest when FSH-LH levels were opposite to this (high-low) and intermediate when FSH-LH levels were low-low or high-high. Associations with LBR and ovarian response were similar as those for PR. AFCs and serum AMH levels were positively and log-linearly associated with PR, LBR and ovarian response. Success rates levelled out above AFC 30 or AMH 5 ng/ml. Treatment outcome was superior among women with polycystic ovaries. Among the studied ORTs, logAFC and logAMH concentration correlated most strongly. After multivariate testing, entering all studied ORTs, AMH and female age remained independently associated with LBR. AMH + AFC + age predicted both poor and excessive ovarian responses with high accuracy. Adjusting for age and oocyte yield, all ORTs remained significant for LBR, implying that ORTs also capture information on oocyte quality. In conclusion, measures of OR are strongly associated with PR, LBR and ovarian response in a log-linear fashion, and partly reflect oocyte quality. The OR spectrum is continuous, from small ‘oligofollicular’ ovaries (the low extreme) to polycystic ovaries (the high extreme). Among the studied ORTs, AMH together with age provide the most powerful basal estimate for IVF/ICSI outcome.
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Etablierung, Validierung und Anwendung einer gaschromatographisch-massenspektrometrischen Methode zur Analyse von Testosteron und 17α-OH-Progesteron im Serum / Methodenvergleich der GC-NCI-MS-Methode mit dem Siemens ADVIA Centaur Immunoassay der Testosteronanalyse / Establishment, validation and application of a GC-MS method for the analysis of testosterone and 17α-OH-progesterone in serum / Method comparsion of GC-NCI-MS and Siemens ADVIA Centaur Immunoassay for testosterone analysisSchön, Liligret Valerie 03 September 2013 (has links)
Ziele:
Die Arbeit hatte die Etablierung und Validierung einer robusten, spezifischen und sensitiven GC-NCI-MS Methode zum Ziel, um Testosteron und 17α-OH-Progesteron im Serum zuverlässig quantifizieren zu können. Anschließend wurde die Methode mit dem Siemens ADVIA Centaur Immunoassay zur Testosteronanalyse verglichen. Hintergrund der Arbeit ist die mangelnde Richtigkeit und Sensitivität der Steroidhormonanalyse mit Immunoassays, inbesondere bei Hormonanylsen in geringen Konzentrationen, wie z.B. Testosteron bei Frauen und Kindern.
Methode:
Die Methode umfasste die Zugabe von deuterierten Internen Standard zu 1 ml Serum, gefolgt von Flüssig-Flüssig-Extraktion mit Ethylacetat und einem Clean-up mittels Festphasenextraktion. Die angereicherten und aufgereinigten Proben können mit Pentafluor¬benzyl¬hydroxylamin-hydrochlorid und MSTFA/TMCS (99:1) erfolgreich derivatisiert und im Anschluss in die GC-MS injiziert werden. Die Methode zeigt eine exzellente chromatographische Trennung. Testosteron und 17-OH-Progesteron wurden im Selected Ion Monitoring detektiert, die Quantifizierung erfolgte durch den Vergleich der Verhältnisse der Peakflächen zwischen Internen Standard und Analyten.
Für den Methodenvergleich, zwischen der GC-MS Methode und dem Siemens ADVIA Centaur Immunoassay, wurde Testosteron in 10 Proben von Männern und 20 Proben von Kindern und Frauen analysiert.
Ergebnisse:
In dem für Männer physiologischen Konzentrationsbereich (2,62 -9,29 ng/ml) konnte eine sehr gute Übereinstimmung der Analysenergebnisse beider Methoden gezeigt werden (r= 0,97). Im Gegensatz dazu fiel im niedrigen Konzentrationsbereich aus Seren von Frauen und Kindern (0,05 - 0,51 ng/ml) eine geringe Übereinstimmung (r= 0,77) der Messergebnisse auf, wobei hier mit dem untersuchten Immunassay im Mittel um 158,9 % höhere Konzentrationen erzielt wurden.
Schlussfolgerung:
Der Methodenvergleich spiegelt die aktuelle Problematik in der Testosteronanalytik wider. So werden Messdifferenzen zu massenspektrometrischen Referenzmethoden auf eine mangelnde analytische Spezifität und Sensitivität, als auch ungenügende Validierung der Immunoassays zurückgeführt. Wenn niedrige Konzentrationen erwartet werden, wie bei der Testosteronanalyse in Serum von Frauen und Kindern, oder wenn zweifelhafte Analysenergebnisse vorliegen, sollte auf massenspektrometrische Referenzmethoden zurückgegriffen werden.
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Détection portale des nutriments et contrôle de l'homéostasie énergétique par l'axe nerveux intestin-cerveauDe Vadder, Filipe 30 June 2014 (has links) (PDF)
La production endogène de glucose est une fonction cruciale de l'organisme, permettant de maintenir l'homéostasie glycémique. Alors que la production accrue de glucose par le foie a des effets délétères, la néoglucogenèse intestinale (NGI) exerce des effets bénéfiques sur l'équilibre métabolique de l'organisme. Les régimes hyperprotéiques sont connus pour leurs effets de satiété. Grâce à des travaux physiologiques et moléculaires chez le rat et la souris, nous montrons dans une première partie que l'effet bénéfique des régimes hyperprotéiques passe par une induction de la NGI. Lors de la digestion des protéines alimentaires, des di- et tripeptides sont libérés dans la veine porte. Ces molécules agissent comme des antagonistes des récepteurs μ-opioïdes de la veine porte, initiant un arc réflexe intestin-cerveau induisant la NGI et la satiété. Dans un deuxième temps, nous proposons un modèle rendant compte des effets bénéfiques des régimes riches en fibres, tels que l'amélioration de la sensibilité à l'insuline et l'induction de la dépense énergétique. Les fibres solubles sont fermentées par le microbiote intestinal, produisant des acides gras à chaîne courte (AGCC), acétate, propionate et butyrate, à l'origine des effets métaboliques observés. Nous montrons que le butyrate active directement les gènes de la NGI dans les entérocytes, et que le propionate se lie aux récepteurs FFAR3 dans le système nerveux périportal, initiant un mécanisme de communication entre l'intestin et le cerveau induisant la NGI. De plus, nous montrons que la modification de la composition du microbiote par les fibres alimentaires n'est pas suffisante en soi pour induire les effets bénéfiques en absence de NGI
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Intérêts et limites de l'approche centrée sur le patient dans une démarche éducatice vis-à-vis du patient diabétique de type 2 en médecine générale : approche phénoménologique exploratoire (étude DEADIEM)Moreau, Alain 05 December 2013 (has links) (PDF)
L'Approche Centrée Patient (ACP) permet sur le plan conceptuel la réalisation d'une démarche éducative vis-à-vis du patient diabétique de type 2. Mais la question de son fonctionnement se pose en pratique clinique de médecine générale. Dans le cadre d'une étude exploratoire qualitative phénoménologique, une Démarche Educative DEADIEM a été testée auprès de 10 patients diabétiques de type 2 inclus par 5 médecins généralistes pour en comprendre son fonctionnement. Cette démarche comprenait l'exploration de la perspective du patient, ce qui est VRAI (Vécu, Représentation, Attentes, Important) pour lui, une démarche explicative, des conseils hygiéno-diététiques adaptés et un objectif de compréhension commune avec le médecin avec évaluation à 3 mois de ses résultats. En confrontant les données du discours avec les modèles transthéorique et transactionnel par procédure de triangulation théorique, cette démarche a corroboré une dynamique d'adaptation " coping ", des processus expérientiels et comportementaux favorisant ou pas des changements. Les médecins traitants ont été sollicités pour parler de leur perception de la relation. L'étude a illustré l'interaction symbolique qui existe entre des représentations " personnages " que chacun se fait de l'autre et qui peuvent bloquer ou faciliter la relation et la compréhension commune. Les médecins traitants ont pu exprimer de manière réaliste leurs limites et les difficultés de la relation transférentielle. A l'issu de cette étude, l'ACP, enrichi par d'autres modèles, est apparue comme un processus thérapeutique systémique qui peut être accessible à tout médecin généraliste, enseignable et faire l'objet de travaux de recherche complémentaires
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Diabetes typ 3? : Molekylärfysiologiska länkar och samband från den samlade litteraturen / Alzheimer’s disease – Diabetes type 3? : The molecular physiology and related links from the comprehensive literatureNicklagård, Erik January 2011 (has links)
Alzheimers sjukdom (AD) är den vanligaste formen av demens och kännetecknas av intracellulärt neurofibrillärt trassel (NFT) bestående av proteinet tau och extracellulära plack, uppbyggda av peptiden amyloid beta (Aβ). En växande skara studier har börjat peka mot att AD är en hjärnspecifik typ av diabetes. Insulinresistens följt av hyperinsulinemi och hyperglykemi är kännetecken för diabetes mellitus typ 2 (DMT2) och har visat sig vara en riskfaktor för AD. Insulin, ett hormon som kontrollerar glukoshomeostasen i perifera nervsystemet (PNS) och är viktigt för minne och inlärning, transporteras över blod-hjärnbarriären i en mättnadsbar transportmekanism och dess koncentration i centrala nervsystemet (CNS) minskar vid DMT2 och AD. Insulin-like growth factor 1 (IGF-1), ett neuronskyddande protein som minskar ogynnsam β-sekretasklyvning av amyloid precursor protein (APP) i amyloidkaskadhypotesen, minskar i koncentration i hjärnan när mycket insulin transporteras in i CNS. γ-sekretas ökar sin aktivitet på APP vid höga halter kolesterol som är vanligt vid DMT2, Aβ fungerar då som en negativ inhibitor till HMG-Coa reduktas (HMGR), enzymet som bildar kolesterol och kan därmed reglera kolesterolhalterna. Regleringssystem för Aβ i blod-hjärnbarriären (BBB) som p-GP, LRP-1 och RAGE rubbas vid DMT2. Aβ och insulin delar samma degraderingssystem, insulin degrading enzyme (IDE), som reglerar halterna Aβ och insulin. Dessutom har Aβ oligomerer visat sig kunna bryta ned insulinreceptorer (IR). Vidare har läkemedel mot diabetes visat sig lindra demens hos AD patienter. I den här rapporten gås de molekylärfysiologiska sambanden igenom i detalj. Slutligen finns det fog för ett samband mellan metabolt syndrom, en riskfaktor för DMT2, och AD.
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