George Briassoulis

The glucocorticoid receptor and its expression in the anterior pituitary and the adrenal cortex: a source of variation in hypothalamic-pituitary-adrenal axis function; implications for pituitary and adrenal tumors.

OBJECTIVEnTo review the expression of the glucocorticoid receptor (GR) in anterior pituitary and adrenocortical cells and tumors derived from these tissues as well as factors that may influence its expression.nnnMETHODSnWe present an overview of the relevant literature, with a focus on data generated from our studies.nnnRESULTSnThe expression of the GR is an essential element of the negative feedback that closes the loop formed by corticotropin-releasing hormone, adrenocorticotropic hormone, and cortisol in the context of the hypothalamic-pituitary-adrenal (HPA) axis. Although the GR expression in anterior pituitary cells-and in particular the corticotrophs-was first demonstrated several years ago, it was not known until relatively recently where, by what cells, and in what form the GR is expressed in the adrenal cortex. The variability in the expression of the GR in pituitary and adrenocortical cells may underlie the substantial differences in HPA axis function across individuals, especially when testing for tumors associated with hypercortisolemia. This expression is influenced by a multitude of tissue-specific factors, which may explain why it is so difficult to interpret (or reproduce) studies that are based on GR functional polymorphisms on different cohorts of patients or even different sets of laboratory animals.nnnCONCLUSIONnThis review highlights the variability in expression and function of the GR in pituitary and adrenocortical cells as one of the reasons for the appreciable differences in HPA axis function across individuals. Particular attention was paid to interactions that may affect the interpretation of diagnostic testing of the HPA axis in patients with pituitary adenomas (Cushing disease) or adrenocortical tumors (Cushing syndrome).

The challenge of developing a new predictive formula to estimate energy requirements in ventilated critically ill children.

BACKGROUNDnTraditionally, energy requirements have been calculated using predictive equations. These methods have failed to calculate energy expenditure accurately. Routine indirect calorimetry has been suggested, but this method is technically demanding and costly. This study aimed to develop a new predictive equation to estimate energy requirements for critically ill children.nnnMETHODSnThis prospective, observational study on ventilated children included patients with an endotracheal tube leak of < 10% and fractional inspired oxygen of < 60%. An indirect calorimetry energy expenditure measurement was performed and polynomial regression analysis was used to develop new predictive equations. The new formulas were then compared with existing prediction equations.nnnRESULTSnData from 369 measurements were included in the formula design. Only weight and diagnosis influenced energy expenditure significantly. Three formulas (A, B, C) with an R² > 0.8 were developed. When we compared the new formulas with commonly used equations (Schofield, Food and Agriculture Organization/World Health Organization/United Nations University, and White equation), all formulas performed very similar, but the Schofield equation seemed to have the lowest SD.nnnCONCLUSIONSnAll 3 new pediatric intensive care unit equations have R² values of > 0.8; however, the Schofield equation still performed better than other predictive methods in predicting energy expenditure in these patients. Still, none of the predictive equations, including the new equations, predicted energy expenditure within a clinically accepted range, and further research is required, particularly for patients outside the technical scope of indirect calorimetry.

Early Response Roles for Prolactin Cortisol and Circulating and Cellular Levels of Heat Shock Proteins 72 and 90α in Severe Sepsis and SIRS

Objective. To evaluate the early heat shock protein (HSP) and hormonal stress response of intensive care unit (ICU) patients with severe sepsis/septic shock (SS) or systemic inflammatory response syndrome (SIRS) compared to healthy subjects (H). Methods. Patients with early (first 48u2009hrs) SS (n = 29) or SIRS (n = 29) admitted to a university ICU and 16 H were enrolled in the study. Serum prolactin, cortisol, and plasma ACTH were determined using immunoassay analyzers. ELISA was used to evaluate extracellular HSPs (eHSP90α, eHSP72) and interleukins. Mean fluorescence intensity (MFI) values for intracellular HSPs (iHSP72, iHSP90α) were measured using 4-colour flow-cytometry. Results. Prolactin, cortisol, and eHSP90α levels were significantly increased in SS patients compared to SIRS and H (P < 0.003). ACTH and eHSP72 were significantly higher in SS and SIRS compared to H (P < 0.005). SS monocytes expressed lower iHSP72 MFI levels compared to H (P = 0.03). Prolactin was related with SAPS III and APACHE II scores and cortisol with eHSP90α, IL-6, and lactate (P < 0.05). In SS and SIRS eHSP90α was related with eHSP72, IL-6, and IL-10. Conclusion. Prolactin, apart from cortisol, may have a role in the acute stress response in severe sepsis. In this early-onset inflammatory process, cortisol relates to eHSP90α, monocytes suppress iHSP72, and plasma eHSP72 increases.

Immunoparalysis: Clinical and immunological associations in SIRS and severe sepsis patients.

Introduction: This study was designed to identify changes in the monocytic membrane marker HLA‐DR and heat shock proteins (HSPs) in relation to T‐regulatory cells (T‐regs) and other immunological marker changes in patients with systemic inflammatory response syndrome (SIRS) or sepsis/septic shock. Methods: Healthy volunteers, intensive care unit (ICU) patients with SIRS due to head injury and ICU patients with severe sepsis/septic shock were enrolled in the current study. Determination of CD14+/HLA‐DR+ cells, intracellular heat‐shock proteins and other immunological parameters were performed by flow cytometry and RT‐PCR techniques as appropriate. Univariate and multivariate analysis examined associations of CD14/HLA‐DR, HSPs, T‐regs and suppressor of cytokine signalling (SOCS) proteins with SIRS, sepsis and outcome. Results: Fifty patients (37 with severe sepsis and 13 with SIRS) were enrolled, together with 20 healthy volunteers used as a control group. Compared to healthy individuals, patients with SIRS and severe sepsis showed progressive decline of their CD14/HLA‐DR expression (0% to 7.7% to 50% within each study subpopulation, p < 0.001). Mean fluorescent intensity (MFI) levels of HSP70 and HSP90 on monocytes and polymorphonuclear cells were significantly higher in SIRS patients compared to controls and fell significantly in severe sepsis/septic shock patients (p < 0.05 for all comparisons). There was no statistically significant difference between subgroups for levels of T‐regulatory cells or relative copies of Suppressor of Cytokine Signalling 3 (SOCS3) proteins. In univariate models percent of CD14/HLA‐DR was associated with mortality (OR: 1.8 95%CI 1.02–3.2, p = 0.05), while in multivariate models after adjusting for CD14/HLA‐DR only younger age and lower Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were associated with increased chances of survival (beta −0.05, OR 0.9, 95% CI 0.9–0.99, p = 0.038 for age and beta −0.11, OR 0.89, 95% CI 0.8–0.99, p = 0.037 for APACHE II score). Conclusions: Significant associations with SIRS and sepsis were found for CD14/HLA‐DR expression and monocyte and polymorphonuclear cell levels of HSP70 and 90. The role of these biomarkers in assessing the prognosis of sepsis needs to be further explored and validated in prospective studies.

Glutamine suppresses Hsp72 not Hsp90α and is not inducing Th1, Th2, or Th17 cytokine responses in human septic PBMCs.

OBJECTIVEnL-Alanyl-glutamine (L-Ala-Gln) is a pharmaco-nutrient commonly used in nutrition regimens due to its immunomodulatory effects. In critically ill patients who are septic, L-Ala-Gln was associated with an increase in mortality. The aim of this study was to investigate whether L-Ala-Gln modulated heat shock protein (Hsp)-72, 90-α, T helper (Th)1, Th2, and Th17 cytokine expression in the peripheral blood mononuclear cells (PBMC) of patients with severe sepsis.nnnMETHODSnTime-dose effects of L-Ala-Gln were compared with those of L-glutamine (L-Gln) and lipopolysaccharide (LPS) and to healthy controls. PBMCs were incubated with 1 or 10 μg/mL LPS, 5 or 10 mM L-Gln, and 5 or 10 mM L-Ala-Gln for different periods of time (0; 4; 24 h) when culture supernatants were harvested.nnnRESULTSnIn both groups, basal Hsp72 increased over time (P < 0.02); Hsp90-α levels declined in controls (P < 0.02) but remained increased in septic patients (P < 0.02), not exhibiting any significant time-response trend. Both Glns suppressed Hsp72 in septic and controls at 10 mM by 4 h (P < 0.045) and Hsp90-α in the control group by 24 h (P < 0.045). LPS did not induce Hsps in either group. L-Ala-Gln did not induce any of the Th1, Th2, and Th17 cytokines in either group.nnnCONCLUSIONnHigh doses of L-Gln or L-Ala-Gln do not induce any of the Th1, Th2, and Th17 cytokines in either healthy or septic human PBMCs. High Gln doses suppress Hsp72 in septic and control PBMCs. Hsp90-α time-series expression declines, contrasting the increasing trend of Hsp72 in healthy controls. Hsp90-α sustains increased levels in septic supernatants, showing a characteristic longitudinal behavior needed further elucidation.

Prognostic markers of pediatric meningococcal sepsis

Having available tools to determine the prognosis of pediatric meningococcal sepsis at admission to the Intensive Care Unit or during the course of the disease constitutes a clinical necessity. Recently, new readily measurable circulating biomarkers have been described as an additional tool for severity classification and prediction of mortality in meningococcal disease. These biomarkers have been associated with increased risk of mortality scores and a number of organ failures in heterogeneous samples of critically ill children. In future, genetic markers may be used for identification of high-risk patients by creating prediction rules for clinical course and sequelae, and potentially provide more insight in the complex immune response in meningococcal sepsis. We briefly summarize the data pointing at the emerging genome-wide expression profiling studies and review the prognostic value of the main markers investigated in pediatric meningococcal sepsis putting them in the current frame of sepsis in general.

Lack of mutations in the gene coding for the hGR (NR3C1) in a pediatric patient with ACTH-secreting pituitary adenoma, absence of stigmata of Cushing's syndrome and unusual histologic features.

Abstract Background: Rare cases of human glucocorticoid receptor (hGRα) (NR3C1) gene mutations have been described in the gemline or somatic state in Cushing’s disease (CD). Aim: We describe a pediatric patient with CD with clinical evidence of partial glucocorticoid resistance (GR) due to the relative absence of stigmata of Cushing’s syndrome (CS). Case description: A 14-year-old boy with slow growth and hypertension, but no other signs of CS was admitted for CD evaluation. Urinary free cortisol levels (UFC) were consistently 2-3-fold the upper normal range. Pituitary magnetic resonance imaging (MRI) revealed a 3×4 mm hypoenhancing lesion in the right side of the pituitary gland anteriorly (microadenoma). A graded dexamethasone suppression test indicated that the patient had partial GR. Histology confirmed an adrenocorticotrophin (ACTH)-producing pituitary adenoma. We hypothesized that a NR3C1 mutation was present. Sequencing of the entire coding region of the gene produced normal results in both peripheral and tumor DNA. Conclusion: We present the case of a pediatric patient with an ACTH-producing tumor but little evidence of CS. No mutations in the coding sequence of NR3C1 were detected. We conclude that low level somatic mosaicism for NR3C1 mutations or a mutation in another molecule participating in hGRα-signaling may account for this case.

Longitudinal Profiles of Metabolism and Bioenergetics Associated with Innate Immune Hormonal Inflammatory Responses and Amino-Acid Kinetics in Severe Sepsis and Systemic Inflammatory Response Syndrome in Children

BACKGROUNDnExperimental data indicate that sepsis influences the mitochondrial function and metabolism. We aim to investigate longitudinal bioenergetic, metabolic, hormonal, amino-acid, and innate immunity changes in children with sepsis.nnnMETHODSnSixty-eight children (sepsis, 18; systemic inflammatory response syndrome [SIRS], 23; healthy controls, 27) were enrolled. Plasma amino acids were determined by high-performance liquid chromatography (HPLC); flow-cytometry expressed as mean fluorescence intensity (MFI) of heat shock protein (HSP) levels from monocytes (m) and neutrophils (n); resistin, adiponectin, and extracellular (e) HSPs evaluated by ELISA; ATP levels in white blood cells by luciferase luminescent assay; lipid peroxidation products (TBARS) by colorimetric test; nitrite and nitrate levels by chemiluminescent assay; biliverdin reductase (BVR) activity by enzymatic assay; and energy-expenditure (EE) by E-COVX.nnnRESULTSnResistin, eHSP72, eHSP90α, and nitrate were longitudinally higher in sepsis compared with SIRS (p<0.05); mHSP72, nHSP72, VO2 , VCO2 , EE, and metabolic pattern were repressed in sepsis compared with SIRS (p<0.05). Septic patients had lower ATP and TBARS compared with controls on day 1, lower ATP compared with SIRS on day 3 (p<0.05), but higher levels of BVR activity. Sepsis exhibited higher phenylalanine levels on day 1, serine on day 3; lower glutamine concentrations on days 3 and 5 (p<0.05). Resistin, inversely related to ATP, was independently associated with sepsis, along with mHSP72 and eHSP90α (p<0.05); TBARS and VO2 were independently associated with organ failure (p<0.05)). Septic nonsurvivors had malnutrition, persistently repressed metabolism, mHSP72, and induced resistin and adiponectin (p<0.05).nnnCONCLUSIONSnA pattern of early longitudinal induction of metabolic-hormones and eHSP72/HSP90α, repression of bioenergetics and innate immunity, hypo-metabolism, and amino-acid kinetics changes discriminate sepsis from SIRS; malnutrition, hypo-metabolism, and persistently increased resistin and adiponectin are associated with poor outcome.

The Role of Protein Kinase A in Anxiety Behaviors.

This review focuses on the genetic and other evidence supporting the notion that the cyclic AMP (cAMP) signaling pathway and its mediator, the protein kinase A (PKA) enzyme, which respond to environmental stressors and regulate stress responses, are central to the pathogenesis of disorders related to anxiety. We describe the PKA pathway and review in vitro animal studies (mouse) and other evidence that support the importance of PKA in regulating behaviors that lead to anxiety. Since cAMP signaling and PKA have been pharmacologically exploited since the 1940s (even before the identification of cAMP as a second messenger with PKA as its mediator) for a number of disorders from asthma to cardiovascular diseases, there is ample opportunity to develop therapies using this new knowledge about cAMP, PKA, and anxiety disorders.

The sweet lung: Chewing gummi bear aspiration.

Inhalation of foreign bodies, a leading cause of accidental death, is most common in preschool children. In this article we report our experience with a 5-year-old Greek girl who presented with a 24-hour history of sore throat, chest pain, and shortness of breath. Emergency bronchoscopy was performed and multiple small chewing gummi bear (HARIBO) particles impacted in the orifices of the right main bronchus and right lobar and segmentalinic bronchi were successfully removed and aspirated. Aspiration of gummi bears, which is for the first time reported, may cause a silent choking episode leading to life-threatening bronchi obstruction at multiple sites, even in children older than 4 years.