How accurate are currently used methods of determining glycemia in critically ill patients, and do they affect their clinical course?
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Blood Chemical Analysis↗
Biomedical subjects
G Chrousos
Publications and source records attributed to G Chrousos.
Endometrial and placental CRH as regulators of human embryo implantation.
Epithelial cells of the human endometrium and differentiated endometrial stromal cells express the corticotropin-releasing hormone (CRH) gene. CRH is also produced by human placental cytotrophoblast. Endometrial and placental CRH are under the endocrine control of gonadal steroids as well as under autocrine/paracrine regulation by prostanoids and interleukins. Human endometrium, myometrium and placenta express the relevant receptors. Human trophoblast and decidualized endometrial cells also express Fas ligand (FasL), a pro-apoptotic molecule. These findings suggest that intra-uterine CRH may participate in local inflammatory phenomena associated with blastocyst implantation, while FasL may assist with maternal immune tolerance to the semi-allograft embryo. A nonpeptidic CRH receptor type 1 (CRH-R1)-specific antagonist decreased the expression of FasL by human trophoblasts, suggesting that CRH regulates the pro-apoptotic potential of these cells in an auto-paracrine fashion. Invasive trophoblasts promoted apoptosis of activated Fas-expressing human T lymphocytes, an effect potentiated by CRH and inhibited by the CRH antagonist. Female rats treated with the CRH antagonist in the first 6 days of gestation had a dose-dependent decrease of endometrial implantation sites and live embryos as well as markedly diminished endometrial FasL expression. However, embryos of mothers lacking T cells (nude rats) and embryos of syngeneic matings were not rejected when mothers were treated with antalarmin, suggesting that the effect of antalarmin on embryonic implantation is not due to a nonspecific toxicity of this compound but a specific effect on T cells. Our data suggest important physiological roles of endometrial and placental CRH in the regulation of blastocyst implantation and early maternal tolerance.
Corticotropin-Releasing Hormone↗
Participation of maternal and fetal CRH in early phases of human implantation: the role of antalarmin.
The hypothalamic neuropeptide corticotropin-releasing hormone (CRH) is produced by several tissues of the female reproductive system. It is also secreted at inflammatory sites and possesses potent pro-inflammatory properties influencing both innate and acquired immune processes. Uterine CRH participates in local immune early pregnancy phenomena, such as decidualization of endometrial strom a and protection of the fetus from maternal immune system. This is maintained through induction of the expression of apoptotic FasL on invasive extravillous trophoblast and maternal decidual cells at the fetal-maternal interface. Furthermore, CRH increases apoptosis of activated T lymphocytes through FasL induction participating in the process of implantation and early pregnancy. Female rats treated with the non-peptidic CRH receptor 1 (CRHR1) specific antagonist antalarmin, in the first 6 days of gestation, have undergone a decrease of endometrial implantation sites and live embryos and markedly diminished endometrial FasL expression.
Animals↗
Preterm birth: associated neuroendocrine, medical, and behavioral risk factors.
Increased CRH secretion by the placenta of pregnant women has been associated with preterm birth. Certain indices of risk, both medical and psychosocial in nature, have been linked to preterm delivery. Levels of total, bound, and free CRH, CRH-binding protein (CRH-BP), and cortisol were measured prospectively in a large sample of pregnant Danish women who delivered preterm and term infants. Measures of maternal serum hormones were taken at 7--23 and 27--37 weeks gestation and, for those who delivered at term, at 37--43 weeks gestation. At 7--23 weeks gestation, maternal levels of total CRH (P = 0.01), bound CRH (P = 0.03), and CRH-BP (P = 0.01) were higher in the preterm than in the term group. At 27--37 weeks gestation, levels of total CRH (P < 0.0001), bound CRH (P < 0.0001), free CRH (P < 0.0001), and cortisol (P < 0.0001) were all higher in the preterm than the term group, whereas levels of CRH-BP (P < 0.0001) were lower in the preterm than in the term group. The best medical and behavioral factors associated with preterm delivery were, respectively, previous preterm delivery (P < 0.0001) and engagement in certain risk-taking behaviors (P = 0.008). The positive relations between preterm delivery and various adverse medical and socioeconomic variables with increases in placental secretion of CRH suggest that the latter may participate in the pathophysiology of preterm delivery.
Adult↗
Perturbations of arginine vasopressin secretion during inflammatory stress. Pathophysiologic implications.
Pro-inflammatory cytokines, such as interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF alpha), released from inflammatory foci, can activate the hypothalamus to produce corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP). These hypothalamic peptides in synergy increase ACTH production by the pituitary gland and hence corticosteroid (CS) secretion by the adrenal cortices. CS dampens inflammation. The pituitary also produces prolactin (PRL), which is pro-inflammatory, and macrophage inhibitory factor (MIF), which by counteracting the anti-inflammatory and immunosuppressive effects of CS, is pro-inflammatory. Lewis rats develop a variety of induced-autoimmune inflammatory conditions, such as streptococcal cell wall arthritis, whereas the histocompatible F344 Fisher rats are resistant to this condition. Lewis rats have a defective hypothalamic-pituitary adrenal (HPA) response to a variety of hypothalamic stimuli, but have augmented systemic secretion of AVP. Patients with rheumatoid arthritis (RA) have deficient CS with exaggerated PRL responses to inflammatory stimuli. Within inflammatory foci, CRH is pro-inflammatory. AVP, which augments autologous mixed lymphocyte reactions, can replace the IL-2 requirement for gamma IFN production by T cells via V1a receptors, and potentiates primary antibody responses, is also pro-inflammatory. Lewis rats have significantly high plasma levels, hypothalamic content, and in vitro release of AVP in comparison to the inflammatory disease-resistant Fischer rats. Immunoneutralization of AVP attenuates inflammatory responses. In Sprague-Dawley rats, AVP potentiates PRL secretion. Preliminary studies in patients with RA have shown that the circulating levels of AVP are significantly increased, which might be a compensatory response to low CS levels or a result of elevated levels of IL-6 in these patients but could nevertheless contribute to rheumatoid inflammation. A similar observation has been made in patients with ankylosing spondylitis.
Animals↗
Decreased corticosensitivity in quiescent Crohn's disease: an ex vivo study using whole blood cell cultures.
Corticosensitivity influences the degree and the duration of an inflammatory reaction by altering target cell responses to endogenous and/or exogenous glucocorticoids. Indeed, different clinical responses to glucocorticoids have been observed among patients with Crohn's disease, suggesting different degrees of corticosensitivity in these subjects. The purpose of this study was to compare the corticosensitivity of patients with quiescent Crohn's disease to that of healthy subjects (HS). Nineteen patients with quiescent Crohn's disease and 14 HS were studied; all patients were steroid-free for at least six months; 7 of the 19 were corticosteroid-dependent (CSD) and treated with nonglucocorticoid immunosuppressants at the time of the study. Corticosensitivity was measured by the inhibition of LPS-induced cytokine secretion in whole blood cell cultures treated with increasing concentrations (10(-9) to 10(-6) M) of dexamethasone. Tumor-necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta) were measured using specific immunoassays. Crohn's disease patients had a markedly decreased dexamethasone-mediated inhibition of TNF-alpha (P < 0.01), IL-6 (P < 0.001), and IL-1 beta (P < 0.01) compared to healthy subjects, with a shift of the dexamethasone dose-response curve to the right. No significant differences in the basal and LPS-stimulated secretion of the three cytokines were observed between CSD and non-CSD patients, and both subgroups of patients had similar degrees of dexamethasone-mediated cytokine inhibition. We conclude that patients with Crohn's disease have a significant decrease in the corticosensitivity of their leukocytes. This may be related to a specific genetic/constitutional background and/or could be acquired, due to inflammation-related endocrine and/or immune factors.
Adult↗
Knocking out the stress response.
Transgenic animals and knockout mice have been generated with defined defects in various components of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system. These models provide valuable and novel insights into the development, crosstalk, organization, and functioning of the stress system.
Animals↗
The hypoplastic inferior petrosal sinus: a potential source of false-negative results in petrosal sampling for Cushing's disease.
Our purpose was to describe the hypoplastic or plexiform inferior petrosal sinus as a potential cause of false-negative sampling results in patients with Cushing's disease. Five hundred and one patients with surgically proven Cushing's disease and negative or equivocal magnetic resonance imaging scans of the pituitary gland underwent petrosal sinus sampling. Four patients (0.8%) with surgically proven Cushing's disease had false-negative results of petrosal sinus sampling. Retrograde inferior petrosal sinograms in these patients were reviewed to evaluate the anatomy of the inferior petrosal sinuses for abnormalities that could have contributed to this misdiagnosis. In addition, the retrograde inferior petrosal sinograms of 100 consecutive patients were reviewed to establish the frequency of asymmetric and/or hypoplastic inferior petrosal sinuses. All four patients with false-negative results of petrosal sampling demonstrated a hypoplastic or plexiform inferior petrosal sinus ipsilateral to an ACTH-secreting microadenoma. When the sampling catheter was in the hypoplastic petrosal sinus, retrograde sinograms from the contralateral side demonstrated anomalous drainage patterns on the side of the hypoplastic sinus. Because the negative results of petrosal sinus sampling false-suggested the presence of the ectopic ACTH syndrome, curative transsphenoidal surgery in these four patients was delayed up to 31 months. We conclude that the presence of a unilateral hypoplastic or plexiform inferior petrosal sinus can result in anomalous drainage from the pituitary gland that may lead to false-negative sampling results in patients with Cushing's disease.
Adolescent↗
Corticotropin-releasing hormone induces skin mast cell degranulation and increased vascular permeability, a possible explanation for its proinflammatory effects.
Mast cells are involved in atopic disorders, often exacerbated by stress, and are located perivascularly close to sympathetic and sensory nerve endings. Mast cells are activated by electrical nerve stimulation and millimolar concentrations of neuropeptides, such as substance P (SP). Moreover, acute psychological stress induces CRH-dependent mast cell degranulation. Intradermal administration of rat/human CRH (0.1-10 microM) in the rat induced mast cell degranulation and increased capillary permeability in a dose-dependent fashion. The effect of CRH on Evans blue extravasation was stronger than equimolar concentrations of the mast cell secretagogue compound 48/80 or SP. The free acid analog of CRH, which does not interact with its receptors (CRHR), had no biological activity. Moreover, systemic administration of antalarmin, a nonpeptide CRHR1 antagonist, prevented vascular permeability only by CRH and not by compound 48/80 or SP. CRHR1 was also identified in cultured leukemic human mast cells using RT-PCR. The stimulatory effect of CRH, like that of compound 48/80 on skin vasodilation, could not be elicited in the mast cell deficient W/Wv mice but was present in their +/+ controls, as well as in C57BL/6J mice; histamine could still induce vasodilation in the W/Wv mice. Treatment of rats neonatally with capsaicin had no effect on either Evans blue extravasation or mast cell degranulation, indicating that the effect of exogenous CRH in the skin was not secondary to or dependent on the release of neuropeptides from sensory nerve endings. The effect of CRH on Evans blue extravasation and mast cell degranulation was inhibited by the mast cell stabilizer disodium cromoglycate (cromolyn), but not by the antisecretory molecule somatostatin. To investigate which vasodilatory molecules might be involved in the increase in vascular permeability, the CRH injection site was pretreated with the H1-receptor antagonist diphenhydramine, which largely inhibited the CRH effect, suggesting that histamine was involved in the CRH-induced vasodilation. The possibility that nitric oxide might also be involved was tested using pretreatment with a nitric oxide synthase inhibitor that, however, increased the effect of CRH. These findings indicate that CRH activates skin mast cells at least via a CRHR1-dependent mechanism leading to vasodilation and increased vascular permeability. The present results have implications for the pathophysiology and possible therapy of skin disorders, such as atopic dermatitis, eczema, psoriasis, and urticaria, which are exacerbated or precipitated by stress.
Animals↗
Hypothalamic-pituitary-adrenal function following cranial irradiation.
We assessed the effect of cranial irradiation on hypothalamic-pituitary (HP)-adrenal function in 17 patients (12 females, 5 males) treated with cranial/ craniospinal irradiation for acute leukemia (2 patients) or tumors distant from the hypothalamus and pituitary (8 medulloblastoma, 3 astrocytoma, 3 rhabdomyosarcoma, 1 ependymoma). Estimated doses of radiation (RT) to the HP region ranged from 18 to 72 Gy. Thirteen of seventeen patients were also treated with chemotherapy. Patients were a median of 3.75 years of age (1.5-19 years) at diagnosis and were studied at a median of 5 years (0.1-20 years) after RT. Patients received corticotropin-releasing factor (oCRF, 1 microgram/kg i.v.), and sampling for cortisol and ACTH levels was performed at -15, 0, 15, 30, 60, 90 and 120 min. The-5- and 0-min levels were combined for a standardized baseline value (Base). Cortisol levels at 0, Base, 30 and 120 min, as well as the peak cortisol response, were significantly lower in the patients. Twelve of seventeen patients' peak cortisol levels fell below the normal range. The patients' mean integrated values for cortisol (area under the curve) were not, however, different from controls. The ACTH responses to oCRF did not differ between patients and controls. No relationship was observed between ACTH or cortisol responses and the time elapsed from treatment or dose of HP RT. Further, in 10 of 12 patients, 0-min dehydroepiandrosterone sulfate levels were lower than the expected normal mean levels for age, sex and pubertal status, and in 4 of these 10 patients the values were below the normal range. These data suggest that some patients treated with HP RT may be at risk for adrenal insufficiency.
Adolescent↗
Chronic imipramine is associated with diminished hypothalamic-pituitary-adrenal axis responsivity in healthy humans.
The hypercortisolism of melancholic depression is thought to reflect hypothalamic hypersecretion of CRH and may be related to the hyperarousal associated with this syndrome. Although chronic administration of imipramine to experimental animals significantly decreases CRH messenger RNA levels in the paraventricular nucleus, it is generally thought that resolution of hypercortisolism following recovery from depression is related to the improvement in mood and decrease in anxiety that accompanies recovery rather than an intrinsic effect of imipramine. The present study was designed to explore whether chronic imipramine administration to healthy, nondepressed volunteers is associated with effects on hypothalamic-pituitary-adrenal (HPA) axis function. We studied basal and provocative measures of HPA axis function in 14 healthy volunteers before and after 6 weeks of imipramine treatment at therapeutic doses. Imipramine was associated with decreased responses in peak ACTH and cortisol to ovine CRH and in peak ACTH to arginine vasopressin (P = 0.02, P = 0.003, and P = 0.02, respectively) without changes in indices of basal HPA axis function. These data are consistent with preclinical findings and support the hypothesis that imipramine has an intrinsic effect on central components of HPA axis function, potentially related to its therapeutic effects.
Adrenocorticotropic Hormone↗
Bone mineral density in women with depression.
BACKGROUND: Depression is associated with alterations in behavior and neuroendocrine systems that are risk factors for decreased bone mineral density. This study was undertaken to determine whether women with past or current major depression have demonstrable decreases in bone density. METHODS: We measured bone mineral density at the hip, spine, and radius in 24 women with past or current major depression and 24 normal women matched for age, body-mass index, menopausal status, and race, using dual-energy x-ray absorptiometry. We also evaluated cortisol and growth hormone secretion, bone metabolism, and vitamin D-receptor alleles. RESULTS: As compared with the normal women, the mean (+/-SD) bone density in the women with past or current depression was 6.5 percent lower at the spine (1.00+/-0.15 vs. 1.07+/-0.09 g per square centimeter, P=0.02), 13.6 percent lower at the femoral neck (0.76+/-0.11 vs. 0.88+/-0.11 g per square centimeter, P<0.001), 13.6 percent lower at Ward's triangle (0.70+/-0.14 vs. 0.81+/-0.13 g per square centimeter, P<0.001), and 10.8 percent lower at the trochanter (0.66+/-0.11 vs. 0.74+/-0.08 g per square centimeter, P<0.001). In addition, women with past or current depression had higher urinary cortisol excretion (71+/-29 vs. 51+/-19 micrograms per day [196+/-80 vs. 141+/-52 nmol per day], P=0.006), lower serum osteocalcin concentration (P=0.04), and lower urinary excretion of deoxypyridinoline (P=0.02). CONCLUSIONS: Past or current depression in women is associated with decreased bone mineral density.
Absorptiometry, Photon↗
Sociotropy, autonomy, stress, and depression in Cushing syndrome.
Cognitive theory ascribes nonendogenous depression to latent dysfunctional beliefs activated by stressors impinging upon core values (e.g., rejection for a sociotropic person). To address ambiguities in past tests of the theory, this study measured personality (Sociotropy-Autonomy Scale) and recent stressors (Life Experience Survey and Hassles Scale) among 14 Cushing syndrome patients and 12 controls. Patients scored nonsignificantly higher in sociotropy, and sociotropy correlated positively with depression among patients. Because depression in Cushing syndrome presumably results from biological dysfunction rather than from the interaction of personality and relevant stressors, these results imply that sociotropy may be a consequence of depression as opposed to a contributory cause. There was no congruence between personality and types of stressors reported, which suggest that mood-dependent recall does not account for past evidence of congruence.
Adult↗
Role of surgery in management of adrenocorticotropic hormone-producing islet cell tumors of the pancreas.
BACKGROUND: Ectopic adrenocorticotropic hormone-producing islet cell tumors of the pancreas (ACTH-ICT) are a rare cause of Cushing's syndrome with a severe and rapidly progressive clinical course. METHODS: Charts were reviewed on all patients evaluated and treated for proven Cushing's syndrome caused by ACTH-ICT (n = 12), specifically for the role of surgery in the management of this disease. RESULTS: Ten (83%) of twelve patients with ACTH-ICT had liver metastases at the time of diagnosis (eight of eight with Zollinger-Ellison syndrome, two of four without Zollinger-Ellison syndrome). Surgical management of the primary tumor included three patients who underwent distal pancreatectomy combined with hepatic resection and one patient who underwent laparoscopic enucleation of a tumor from the pancreatic tail. Eight of twelve patients underwent bilateral adrenalectomy to control symptoms of Cushing's syndrome, including three patients who underwent concurrent distal pancreatectomy and hepatic resection. Six of twelve patients died of the disease within 2 1/2 years of diagnosis, four are alive with progressive hepatic metastases, and one has biochemical evidence of disease. CONCLUSIONS: ACTH-ICT of the pancreas is an aggressive tumor, particularly when there is coproduction of gastrin. The benefit of aggressive surgical resection of primary or metastatic ACTH-ICT has not been established. However, palliative bilateral adrenalectomy is justified, because no patients had biochemical cures after aggressive surgical resection in this series.
ACTH Syndrome, Ectopic↗
Excessive and dysregulated secretion of prolactin in rheumatoid arthritis: immunopathogenetic and therapeutic implications.
Prolactin (PL) is essential for the normal function of the immune system. It is required for the induction of a number of autoimmune conditions in experimental animals. The role of prolactin in the immunopathogenesis of autoimmune human disease has not been established. RA is characterized by a variety of immune and inflammatory processes which determine disease activity. It has a pronounced diurnal periodicity with a peak at 03.15 hours. Since PL has a diurnal rhythm of secretion in man with a peak at about 02.00 hours, it may contribute to the nocturnal worsening of RA. We show that patients with RA secrete an excess of prolactin as evidenced by an upregulated diurnal periodicity and an abnormal increase in plasma prolactin concentration following surgery. By contrast, patients with chronic osteomyelitis, who had chronic inflammation of similar severity to patients with RA, had a normal prolactin diurnal rhythm and response to surgery. Hence, the abnormal changes in prolactin physiology seen in RA appear to be a feature of the disease per se rather than related to chronic inflammation. The elevated levels of prolactin may contribute to disease activity by augmenting immune processes and may be an additional genetic factor, independent of HLA-DR4, in the immunopathogenesis of RA. Furthermore, the effective inhibition of prolactin secretion and/or action may have potential as therapy for RA.
Adult↗
Suppression of hypothalamic-pituitary-adrenal axis responsiveness to stress in a rat model of acute cholestasis.
Cholestatic patients undergoing surgery have increased mortality and demonstrate clinical features suggestive of adrenal insufficiency. To examine whether cholestasis influences the status of the hypothalamic-pituitary-adrenal axis, we evaluated rats with acute cholestasis caused by bile duct resection (BDR) and sham-operated and unoperated controls. Basal unstressed plasma concentrations of ACTH and corticosterone were similar in BDR and sham-operated and unoperated control rats. However, exposure of BDR rats to saturated ether vapor resulted in significantly less ACTH and corticosterone release in plasma than in the control animals. To understand the mechanism(s) of decreased HPA axis responsiveness to ether stress in cholestasis, we administered corticotropin-releasing factor (CRF) and measured hypothalamic content, mRNA levels and in vitro secretion of CRF and arginine vasopressin (AVP), the two principal secretagogues of ACTH. In BDR animals, ACTH responses to CRF were decreased and hypothalamic content of CRF and CRF mRNA expression in the paraventricular nucleus were decreased by 25 and 37%, respectively. Furthermore, CRF release from hypothalamic explants of BDR rats was 23% less than that of controls. In contrast to CRF, hypothalamic content of AVP was 35% higher, AVP mRNA in the paraventricular nucleus was increased by 6.6-fold, and hypothalamic explant release of AVP was 24% higher in BDR rats than in control animals. Pituitary ACTH contents were similar in BDR and sham resected rats, but higher than unoperated controls. These findings demonstrate that acute cholestasis in the rat is associated with suppression of hypothalamic-pituitary-adrenal axis responsiveness to stress and demonstrate a dissociation between mechanisms of ACTH regulation mediated by CRF and AVP.
Acute Disease↗
Defective hypothalamic response to immune and inflammatory stimuli in patients with rheumatoid arthritis.
OBJECTIVE: To determine the integrity of the hypothalamic-pituitary-adrenal (HPA) axis responses to immune/inflammatory stimuli in patients with rheumatoid arthritis (RA). METHODS: Diurnal secretion of cortisol and the cytokine and cortisol responses to surgery were studied in subjects with active RA, in subjects with chronic osteomyelitis (OM), and in subjects with noninflammatory arthritis, who served as controls. RESULTS: Patients with RA had a defective HPA response, as evidenced by a diurnal cortisol rhythm of secretion which was at the lower limit of normal in contrast to those with OM, and a failure to increase cortisol secretion following surgery, despite high levels of interleukin-1 beta (IL-1 beta) and IL-6. The corticotropin-releasing hormone stimulation test in the RA patients showed normal results, thus suggesting a hypothalamic defect, but normal pituitary and adrenal function. CONCLUSION: These findings suggest that RA patients have an abnormality of the HPA axis response to immune/inflammatory stimuli which may reside in the hypothalamus. This hypothalamic abnormality may be an additional, and hitherto unrecognized, factor in the pathogenesis of RA.
Adult↗
Abnormal neuroendocrine immune communications in patients with rheumatoid arthritis.
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Adrenal Cortex Hormones↗