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Charis Liapi

Bio: Charis Liapi is an academic researcher from National and Kapodistrian University of Athens. The author has contributed to research in topics: Na+/K+-ATPase & Ca(2+) Mg(2+)-ATPase. The author has an hindex of 18, co-authored 67 publications receiving 1185 citations. Previous affiliations of Charis Liapi include National Institutes of Health & Athens State University.


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Journal ArticleDOI
TL;DR: The IMI restoring effect, especially in the case of the 14-day cold swim stress, also suggests an association of antidepressant effect with the duration of drug treatment, and a distinct effect of the 13-day chronic mild stress on HPA axis.
Abstract: In the present study, an attempt was made to compare three stress models and their effects on the hypothalamic-pituitary-adrenal (HPA) axis, the thymus, the thyroid hormones and the glucose levels. The three different stress models were the chronic mild stress (CMS), the 14-day and the 1-day cold swim stress model. The CMS procedure caused a decrease in thymus weight and rendered no changes on glucose, the adrenocorticotropin hormone (ACTH) or the adrenals. Administration of imipramine (IMI) after the third week of CMS did not reverse the decrease in thymus weight. The 14-day cold swim stress doubled ACTH levels and the adrenal weight and reduced thymus weight, while total thyroxine (tT4), total triiodothyronine (tT3) and glucose levels were unaffected. IMI treatment restored the weights of the adrenal and thymus glands. One-day cold swim stress did not induce any statistically significant effect on the tested physiological parameters. The above findings indicate a distinct effect of the 14-day cold swim stress on HPA axis. Relative to CMS or the 14-day cold swim stress, no effect was induced by the 1-day cold swim stress. The IMI restoring effect, especially in the case of the 14-day cold swim stress, also suggests an association of antidepressant effect with the duration of drug treatment.

114 citations

Journal ArticleDOI
TL;DR: From structure-activity relationships of the pairs morphine+cineole and naloxone+beta-pinene, it was shown that similarities exist in the stereochemistry and in the respective atomic charges of these molecules.
Abstract: 1,8-cineole (cineole) and beta-pinene, two monoterpenes isolated from the essential oil obtained from Eucalyptus camaldulensis Dehn leaves were tested for antinociceptive properties Tail-flick and hot-plate methods, reflecting the spinal and supraspinal levels, respectively, were used in mice and/or rats using morphine and naloxone for comparison Cineole exhibited an antinociceptive activity comparable to that of morphine, in both algesic stimuli A significant synergism between cineole and morphine was observed, but naloxone failed to antagonize the effect of cineole Beta-pinene exerted supraspinal antinociceptive actions in rats only and it reversed the antinociceptive effect of morphine in a degree equivalent to naloxone, probably acting as a partial agonist through the mu opioid receptors From structure-activity relationships of the pairs morphine+cineole and naloxone+beta-pinene, it was shown that similarities exist in the stereochemistry and in the respective atomic charges of these molecules Further studies are in progress in order to elucidate the mechanism of action of the two terpenoids

106 citations

Journal ArticleDOI
TL;DR: Stress levels of glucocorticoids, administered over a 5-day interval, block the estradiol-stimulated growth of female sex hormone target tissues, suggesting that another mechanism by which the HPA may influence reproductive function during stress is by a direct effect of gluc Cocorticoid on the target tissues of sex steroids.
Abstract: Stress-related activation of the hypothalamic-pituitary-adrenal axis (HPA) is associated with suppression of the reproductive axis. This effect has been explained by findings indicating that corticotropin-releasing hormone suppresses hypothalamic gonadotropin-releasing hormone (GnRH) secretion via an opioid peptide-mediated mechanism, and that glucocorticoids suppress both GnRH and gonadotropin secretion and inhibit testosterone and estradiol production by the testis and ovary, respectively. To evaluate whether glucocorticoids suppress the effects of estradiol on its target tissues, we examined the ability of dexamethasone to inhibit estradiol-stimulated uterine and thymic growth in ovariectomized rats. Estradiol alone, given daily for 5 days, caused dose-dependent uterine and thymic growth. Dexamethasone alone, given daily for 5 days, caused a dose-dependent decrease in body weight gain and in thymic growth. When estradiol and dexamethasone were administered simultaneously, however, body weight gain and thymic growth were also inhibited (p less than 0.05). Dexamethasone decreased estradiol-induced uterine cytosolic and nuclear estrogen receptor concentrations (E2 R0, p less than 0.05; E2nR0, respectively), but had no effect on estradiol-induced progesterone receptor concentrations (P4R0, p greater than 0.05). Levels of uterine glucocorticoid receptors were not affected by estrogen and/or dexamethasone treatment. These findings suggest that stress levels of glucocorticoids, administered over a 5-day interval, block the estradiol-stimulated growth of female sex hormone target tissues. This effect may be partially mediated by a glucocorticoid-induced decrease of the estradiol receptor concentration. Thus, another mechanism by which the HPA may influence reproductive function during stress is by a direct effect of glucocorticoids on the target tissues of sex steroids.

100 citations

Journal ArticleDOI
TL;DR: The aim of this review is to provide an up-to-date synopsis of the available knowledge regarding the aforementioned alterations that take place in the hippocampus due to fetal-, neonatal- or adult-onset hypothyroidism.
Abstract: Thyroid hormones (THs) exert a broad spectrum of effects on the central nervous system (CNS). Hypothyroidism, especially during CNS development, can lead to structural and functional changes (mostly resulting in mental retardation). The hippocampus is considered as one of the most important CNS structures, while the investigation and understanding of its direct and indirect interactions with the THs could provide crucial information on the neurobiological basis of the (frequently-faced in clinical practice) hypothyroidism-induced mental retardation and neurobehavioral dysfunction. THs-deficiency during the fetal and/or the neonatal period produces deleterious effects for neural growth and development (such as reduced synaptic connectivity, delayed myelination, disturbed neuronal migration, deranged axonal projections, decreased synaptogenesis and alterations in neurotransmitters' levels). On the other hand, the adult-onset thyroid dysfunction is usually associated with neurological and behavioural abnormalities. In both cases, genomic and proteomic changes seem to occur. The aim of this review is to provide an up-to-date synopsis of the available knowledge regarding the aforementioned alterations that take place in the hippocampus due to fetal-, neonatal- or adult-onset hypothyroidism.

78 citations

Journal ArticleDOI
TL;DR: Tregs and NK cells may be important regulators of thyroid cancer progression and positively correlated with advanced disease stage.
Abstract: Context: The immune system seems to play a key role in preventing metastasis and recurrence of thyroid cancer. T regulatory lymphocytes (Tregs) and natural killer (NK) cells play an important role in the dysfunction of the host immune system in cancer patients. Objective: We investigated thyroid gland infiltration by Tregs and NK cells in patients with papillary thyroid cancer (PTC) and thyroid nodular goiter (TNG). The correlation between the extent of the disease and the lymphocytic infiltration of Tregs and NK cells was examined. Design, Setting, and Participants: A total of 65 patients with PTC, 25 with TNG, and 50 healthy controls were studied. Blood and tissue samples from 28 patients with PTC and 13 with TNG and blood samples from the healthy controls were analyzed for T4 (CD3+CD4+), T8 (CD3+CD8+), NK (CD3−CD16+CD56+), and CD4+CD25+CD127−/low Tregs by flow cytometry (FC). Tissue samples were also analyzed for Foxp3+ Tregs by immunohistochemistry. Results: Tregs showed greater infiltration in thyroi...

68 citations


Cited by
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Journal ArticleDOI
04 Mar 1992-JAMA
TL;DR: The main components of the stress system are the corticotropin-releasing hormone and locus ceruleus-norepinephrine/autonomic systems and their peripheral effectors, the pituitary-adrenal axis, and the limbs of the autonomic system as discussed by the authors.
Abstract: Objective. —This article defines stress and related concepts and reviews their historical development. The notion of a stress system as the effector of the stress syndrome is suggested, and its physiologic and pathophysiologic manifestations are described. A new perspective on human disease states associated with dysregulation of the stress system is provided. Data Sources. —Published original articles from human and animal studies and selected reviews. Literature was surveyed utilizing MEDLINE and the Index Medicus . Study Selection. —Original articles from the basic science and human literature consisted entirely of controlled studies based on verified methodologies and, with the exception of the most recent studies, replicated by more than one laboratory. Many of the basic science and clinical studies had been conducted in our own laboratories and clinical research units. Reviews cited were written by acknowledged leaders in the fields of neurobiology, endocrinology, and behavior. Data Extraction. —Independent extraction and cross-referencing by the authors. Data Synthesis. —Stress and related concepts can be traced as far back as written science and medicine. The stress system coordinates the generalized stress response, which takes place when a stressor of any kind exceeds a threshold. The main components of the stress system are the corticotropin-releasing hormone and locus ceruleus-norepinephrine/autonomic systems and their peripheral effectors, the pituitary-adrenal axis, and the limbs of the autonomic system. Activation of the stress system leads to behavioral and peripheral changes that improve the ability of the organism to adjust homeostasis and increase its chances for survival. There has been an exponential increase in knowledge regarding the interactions among the components of the stress system and between the stress system and other brain elements involved in the regulation of emotion, cognitive function, and behavior, as well as with the axes responsible for reproduction, growth, and immunity. This new knowledge has allowed association of stress system dysfunction, characterized by sustained hyperactivity and/or hypoactivity, to various pathophysiologic states that cut across the traditional boundaries of medical disciplines. These include a range of psychiatric, endocrine, and inflammatory disorders and/or susceptibility to such disorders. Conclusions. —We hope that knowledge from apparently disparate fields of science and medicine integrated into a working theoretical framework will allow generation and testing of new hypotheses on the pathophysiology and diagnosis of, and therapy for, a variety of human illnesses reflecting systematic alterations in the principal effectors of the generalized stress response. We predict that pharmacologic agents capable of altering the central apparatus that governs the stress response will be useful in the treatment of many of these illnesses. ( JAMA . 1992;267:1244-1252)

3,373 citations

Journal ArticleDOI
TL;DR: The Brush Foundation studies on human growth and development, begun in 1931 and terminated in 1942, have been intensively reviewed and studied by Dr. Greulich and Miss Pyle in the formulation of this Radiographic Atlas of Skeletal Development of the Hand and Wrist.
Abstract: The Brush Foundation studies on human growth and development, begun in 1931 and terminated in 1942, have been intensively reviewed and studied by Dr Greulich and Miss Pyle in the formulation of this Radiographic Atlas of Skeletal Development of the Hand and Wrist Serial radiographs of from 2 to 20 hand-films made at successive examinations of each of 1000 boys and girls made up the radiographic material Standards were selected that were judged to be the most representative of the central tendency or anatomic mode of each chronologic age group from birth through 18 years

1,547 citations

Journal ArticleDOI
Paul Willner1
TL;DR: There is overwhelming evidence that under appropriate experimental conditions, CMS can cause antidepressant-reversible depressive-like effects in rodents; however, the ‘anomalous’ profile that is occasionally reported appears to be a genuine phenomenon, and these two sets of behavioural effects appear to be associated with opposite patterns of neurobiological changes.
Abstract: The chronic mild stress (CMS) model of depression has high validity but has in the past been criticized for being difficult to replicate. However, a large number of recent publications have confirmed

1,497 citations

Journal ArticleDOI
TL;DR: The purpose of this review is to define the concepts of stress and the stress response from a historical perspective, present a dynamic overview of the biobehavioral mechanisms that participate in the Stress Response, and examine the consequences of stress on the physiologic and behavioral well-being of the organism by integrating knowledge from apparently disparate fields of science.

823 citations

Journal ArticleDOI
TL;DR: The female reproductive system is regulated by the hypothalamic-pituitary-adrenal axis, which is activated during stress and produces the clinical phenomenology of what Hans Selye described as the stress syndrome.
Abstract: The hypothalamic-pituitary-adrenal axis exerts profound, multilevel inhibitory effects on the female reproductive system. Corticotropin-releasing hormone (CRH) and CRH-induced proopiomelanocortin peptides inhibit hypothalamic gonadotropin-releasing hormone secretion, whereas glucocorticoids suppress pituitary luteinizing hormone and ovarian estrogen and progesterone secretion and render target tissues resistant to estradiol. The hypothalamic-pituitary-adrenal axis is thus responsible for the "hypothalamic" amenorrhea of stress, which is also seen in melancholic depression, malnutrition, eating disorders, chronic active alcoholism, chronic excessive exercise, and the hypogonadism of the Cushing syndrome. Conversely, estrogen directly stimulates the CRH gene promoter and the central noradrenergic system, which may explain adult women's slight hypercortisolism; preponderance of affective, anxiety, and eating disorders; and mood cycles and vulnerability to autoimmune and inflammatory disease, both of which follow estradiol fluctuations. Several components of the hypothalamic-pituitary-adrenal axis and their receptors are present in reproductive tissues as autacoid regulators. These include ovarian and endometrial CRH, which may participate in the inflammatory processes of the ovary (ovulation and luteolysis) and endometrium (blastocyst implantation and menstruation), and placental CRH, which may participate in the physiology of pregnancy and the timing of labor and delivery. The hypercortisolism of the latter half of pregnancy can be explained by high levels of placental CRH in plasma. This hypercortisolism causes a transient postpartum adrenal suppression that, together with estrogen withdrawal, may partly explain the depression and autoimmune phenomena of the postpartum period.

658 citations