Compensatory Elevations Research Articles

PMON226 Primary Ovarian Insufficiency: A Case of a Missed Puberty

Abstract Premature Ovarian Insufficiency (POI) is a loss of ovarian function in women less than 40 years old. We present a case of a female with primary amenorrhea due to autoimmune primary ovarian insufficiency (APOI), in which diagnosis was delayed as she had normal breast and pubic/axillary hair development. A 18-year-old female presented to endocrine clinic for evaluation of primary amenorrhea and hypoplastic uterus and ovaries. During her regular follow ups with her pediatrician it was noted that she had not undergone menarche but since her breast development was normal, further evaluation was not pursued. She had a complicated social history and missed several of her follow up appointments. However, further evaluation was done after she presented with severe pain during intercourse. During her physical exam, it was found she had a vaginal opening of 4 cm with an unpalpable cervix. She did however have pubic/axillary hair and breast development consistent with Tanner stage V. Pelvic MRI showed hypoplastic uterus/ovaries. Her lab work revealed she had a total testosterone of 28ng/dL, prolactin 11.1ng/mL, TSH 1.68iIU/mL, LH 42.2mIU/mL, FSH99.77 mIU/mL, estradiol29.36 pg/ML, AMH 3.1ng/mL. Her karyotype was 46XX. Testing for Fragile×Syndrome and 21 hydroxylase antibodies were negative. Anti-ovarian antibody (AOA) was obtained and found to be positive (1: 160). She was diagnosed with APOI and started on estrogen with a goal to increase to adult doses over 1.5-2 years. Progestins are planned to be introduced once she reaches adult doses of estrogen or develops breakthrough bleeding. Typical presentation of patients with POI is primary amenorrhea and lack of breast development during puberty. However, it is important to remember that there can be a broad spectrum of presenting symptoms with variable breast, uterine, and ovarian development as not all patients have the same degree of estrogen deficiency. This is a case of a patient with POI with hypoplastic uterus and ovaries who had Tanner V breast development. Given this patients ovarian atrophy it is likely that the majority of estrogen production originated from adrenal glands and fat cells, which contributed to the normal development of secondary sexual characteristics delaying her diagnosis. Therefore, identification of abnormal menstrual patterns in adolescence should always raise concern for POI even in the setting of normal breast and pubic/axillary hair development. POI is due to premature deprivation of estrogen with subsequent amenorrhea and compensatory elevations in FSH/LH. Early diagnosis of this condition can prevent potential health complications in such as decreased bone mineral density, psychological complications, and extremely painful intercourse as our patient had. It is important to note that fertility in patients with POI is also unpredictable, however earlier diagnosis/treatment can improve fertility preservation, especially in women with normal AMH levels such as this patient. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

MTOR Restricts Chromatin Access and Genomic Activity to Maintain Hematopoietic Stem Cell Quiescence and Engraftment

mTOR kinase is an anti-cancer drug target that integrates signals from nutrients, growth factors, and cellular energy status to control cell growth and proliferation, but its biological function in hematopoietic stem cells remains unclear. Numerous studies by using rapamycin or mTOR kinase inhibitors have indicated that mTOR inhibition suppresses chromatin access and gene expression and inhibits cell growth. Consistent with the notion that mTOR targeting suppresses gene activation, hyperactivation of mTOR by deletion of negative regulators of mTOR, TSC1/TSC2 or PTEN, causes a loss of quiescence and exhaustion of HSCs. To directly examine the function of mTOR and its kinase activity in HSC regulation, we used the conditional Mx-Cre;mTORflox/flox and the Mx-Cre;mTORflox/knockin mice that produce the mTOR-/- and the mTOR kinase-activity deficient D2338A mutant knockin genotype, respectively, upon poly I:C induced Cre recombination. We have determined the phenotypic, genomic and molecular effects of their HSCs. Our previous studies have found that depletion of mTOR drastically affected hematopoiesis, with a marked reduction in total BM cellularity and transient increase in the number of HSCs in bone marrow. Remarkably, mTOR-/- HSCs displayed a loss of quiescence, increased proliferation and a normal survival index (Guo et al., Haematologic a 98:1353). Our current study has found similar phenotypes of the HSCs in increased number and proliferation in the Mx-Cre;mTORflox/knockin mice where the mTOR kinase activity is abolished. Both mTOR-/- and mTORKI/- HSCs are defective in engraftment upon competitive transplant into recipient mice, with a clear molecular signature of drastically reduced downstream effectors p-S6K and p-4E-BP. ATAC-seq reveals that loss of mTOR or mTOR kinase activity results in selectively increased chromatin access and global gene activation, in contrast to the reported effects by mTOR inhibitors such as rapamycin or pp242/AZD2014. ChIP-seq of two active histone markers, H3K27Ac and H3K4Me3, yields consistent results that chromosome of the HSCs are activated upon the loss of mTOR or its kinase activity. In particular, increased H3K27Ac and H3K4Me3 ChIP-seq activities are observed in both the upstream and downstream region of c-myc locus, consistent with an activated c-myc expression. RNA-seq analysis reveals that upon mTOR KO or KI, thousands of genes exhibit differential expression. The up-regulated genes are particularly enriched in functions involved in ribosome biogenesis/protein translation, cell cycle progression, cell fate determination, and survival. Analysis using the STRING functional interaction network to search for the compensatory genes/pathways discovers a number of likely compensatorily upregulated genes, upon mTOR KO or KI, that share a significant number of interacting genes with mTOR, including c-myc, Fos, and Jun. These genes are enriched in pathways such as EGFR-MAPK pathway, PI3K-Akt pathway, Jak-Stat pathway, and NFkB pathway, which may compensate for mTOR loss. RT-PCR and Western blotting further verify that loss of mTOR or its kinase activity causes elevated mRNA and protein expression of selected compensatory genes, including c-myc, Fos, Jun, and Pik3cd. In addition, broad compensatory elevations in ribosome and translation machinery gene expression, activation of RNA pol-II, and activation of several interesting compensatory pathways are seen. The BET inhibitor, JQ1, that inhibits c-myc activity readily suppresses the hyper-proliferative phenotype of mTOR-/- and mTORKI/-HSCs. Thus, contrary to dogma established mostly by transient rapamycin or kinase inhibitor usages, our genetic and genomic studies demonstrate that mTOR, through its kinase activity, plays a restrictive role to maintain chromosomal access and genomic activity of HSCs. Loss of mTOR or its kinase activity unleashes a compensatory chromosomal and gene activation effects that involve master regulators of gene activities such as c-myc and Fos, protein translation and ribosomal proteins, and cell growth signaling pathways. These genomic changes may cause the HSC loss of quiescence and engraftment phenotypes seen upon mTOR loss, and need to be taken into consideration in the development of new generations of mTOR targeted therapy and combinatory therapy.Disclosures: No relevant conflicts of interest to declareASH Members: Yi Zheng DisclosuresNo relevant conflicts of interest to declare.

Thirst perception exacerbates objective mental fatigue

Thirst is represented within the anterior cingulate and insular cortices, and may share some common neuroanatomical structures that are implicated with the regulation of mental fatigue. This novel study investigated whether thirst might modulate the subjective, behavioural, or neurophysiological representations of mental fatigue. In a crossover design, thirst was monitored in 15 males during 60 min of cycling in normothermic conditions. Participants either consumed water to the dictates of their thirst (sated), or fluid was withheld and replaced with periodic salt water mouth rinses (thirst). Following either satiety or thirst, a 60 min modified Stroop task was completed to evoke mental fatigue. Prefrontal cortex (PFC) haemodynamics were monitored throughout the prolonged task, and subjective perceptions of fatigue were reported through a visual analogue scale. Behavioural performance was quantified as the total number of Stroop task iterations completed in the mentally fatiguing task, and by collating response time and accuracy into the inverse efficiency score (IES) for each 5 min interval throughout the task. During thirst, fewer iterations were completed and poorer IES performance was evident toward the latter portion of the mentally fatiguing task. Compensatory elevations in PFC oxyhaemoglobin were produced in each condition, however, differed temporally, and were premature during thirst. A diminished capacity to sustain cognitive performance is likely the product of an inability to preserve the distribution of resources within the prefrontal cortex, due to heightened activation about thirst regulatory centres. These data provide novel insight into the relationship between thirst and mental fatigue, and suggest that drinking to the dictates of thirst may be a pertinent strategy to sustain prolonged cognitive performance.

Heme oxygenase-1 induction by hemin prevents oxidative stress-induced acute cholestasis in the rat.

We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.

Bilateral adrenal hyperplasia and NR3C1 mutations causing glucocorticoid resistance: Is there an association?

Glucocorticoids signal through their cognate, ubiquitously expressed glucocorticoid receptor (GR), which influences the transcription of a large number of target genes. Several genetic defects, including point mutations, deletions or insertions in the NR3C1 gene that encodes the GR, have been associated with familial or sporadic generalized glucocorticoid resistance or Chrousos syndrome. One of the clinical manifestations of this rare endocrine condition is bilateral adrenal hyperplasia due to compensatory elevations of plasma ACTH concentrations. In this commentary, we discuss the interesting findings of the recently published French MUTA-GR Study, and present our perspective on the evolving field of NR3C1 pathology.

Screening for Vitamin D Deficiency in Black Americans: Comparison of Total, Free, Bioavailable 25 Hydroxy Vitamin D Levels with Parathyroid Hormone Levels and Bone Mineral Density.

There is debate surrounding the adequacy of total and free 25 hydroxy vitamin D [25(OH)D] levels in black Americans who have inherently high bone mineral density [BMD] and low serum concentration of vitamin D binding proteins [VDBP]. Retrospective analysis of serum samples and BMD analyses from the African American Health Study [AAHS] cohort. The AAHS is a population-based longitudinal study initiated to examine issues of disability and frailty among urban-dwelling black Americans in the city of Saint Louis, Missouri. 122 men and 206 women, age 60.2 ± 4.3 years. Retrospective analysis. Total 25(OH)D, VDBP, PTH, and BMD of the lumbar spine and hip by dual energy x-ray photometry (DXA). Free and bioavailable vitamin D levels were calculated using serum concentrations and affinity constants for the VDBP (Gc1F and Gc1S) phenotypes. Serum total 25(OH)D levels were 14.6 ± 8.9 ng/mL (36 ± 22 nmol/L). Vitamin D insufficiency was estimated by compensatory elevations of PTH above the normal range (> 65 pg/mL). PTH levels were within the normal reference range in > 95% of the samples at total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L). There was no difference in the correlation of the reciprocal relationship of vitamin D vs parathyroid hormone between the VDBP phenotypes. Receiver operating characteristic curve analyses indicated that serum total 25(OH)D discriminated sufficiency from insufficiency at least as well as the calculated levels of the free and bioavailable vitamin D. Very low levels of total 25(OH)D (≤ 8 ng/mL, ≤20 nmol/L) were associated with decreased BMD (p=0.02), but higher levels of 25(OH)D did not show statistical differences in BMD. Total 25(OH)D levels of ≤ 8ng/mL (≤20 nmol/L) are associated with clinically significant changes in BMD, whereas total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L) suppressed PTH and were not associated with deficiencies in BMD. Lower levels of 25(OH)D may be acceptable for bone health in black than in white Americans.

Coping and Cardiac Troponin T – A Risk for Hypertension and Sub-Clinical ECG Left Ventricular Hypertrophy: The SABPA Study

Defensive coping (DefS) was associated with cardiovascular disease (CVD) susceptibility in Blacks. Whether coping strategies will associate with sub-clinical left ventricular hypertrophy (electrocardiographic-left ventricular hypertrophy [ECG-LVH] or Cornell product), cardiomyocyte injury and blood pressure (BP), is unclear. Therefore, we assessed relationships between ECG-LVH, cardiac troponin T (cTnT) and 24-hour BP in bi-ethnic groups when habitually utilising a certain coping style, and these groups when having a stress-related cTnT cut-point of 4.2ng/L. A target population study included a Black (n=190) and White (n=204) teachers' gender cohort (20-65years) from South Africa. The Coping Strategy Indicator determined DefS, social support and avoidance coping scores. Fasting blood samples, 10-lead ECG, 24-hour BP and ECG data were obtained. Interaction effects showed no gender, social support and avoidance coping differences. Stratification of groups was done for ethnicity and DefS. Blacks sought more social support, used less avoidance coping and presented with higher CVD susceptibility. Hypertension prevalence and ECG-LVH levels in DefS Blacks (63%) were higher compared to DefS Whites (40%). Multivariate regression analyses showed positive associations between Cornell product, cTnT and BP [p≤0.05] in DefS Blacks only. Their 24-hour systolic blood pressure (SBP) was associated with time-domain depressed heart-rate-variability and prolonged ST-segment-depression especially when applying an established stress-related cTnT ≥ 4.2ng/L cut-point. Defensive coping facilitated autonomic hyperactivity, myocardial injury and subsequent compensatory BP elevations as possible homeostatic reflexes to alleviate myocardial perfusion deficits. The resulting pressure overload increased sub-clinical wall remodelling and ischaemic heart disease risk in Blacks utilising habitual defensiveness. We therefore recommend regular ECG and high sensitivity cTnT screening in asymptomatic patients with emotional stress susceptibility. Longitudinal evidence is needed to confirm causality and progression of cardiomyopathy risk.

Study of Systemic and Microvascular Responses to Progressive Hemolytic Anemia in Rats

Hemolytic Anemia (HA) is characterized by an increase in the ratio of red blood cell destruction to production, which results in reduced oxygen carrying capacity, tissue hypoxia, inflammation, and corresponding clinical manifestations. The microvasculature is the primary site of vascular resistance and gas exchange, and is well suited to studying the subclinical progression of HA. HA was induced in male Sprague Dawley rats by intraperitoneal administration of phenylhydrazine (PHZ) per the following dosing schedule: Group 1 (100 mg/kg on Day 1) and Group 2 (100 mg/kg on Day 1, and 50 mg/kg on Day 2). Group 3 (baseline; BL) was an untreated time control. Rats were surgically prepared for the following systemic and microvascular measurements: total hemoglobin (tHb), mean arterial pressure (MAP), heart rate, pulse pressure (PP), arteriolar contractile response to three doses of phenylephrine (PE; 0.01, 0.1, 1 mg/kg; I.V), and tissue oxygenation (PISFO2). PHZ reduced tHb by 47 and 75% for Groups 1 and 2 respectively. The 47% decrease in tHb for Group 1 was associated with the following changes from BL (Group 3): MAP decreased by 12%, PP increased by 121%, and PISFO2 decreased 23%. A 75% decrease in tHb (Group 2) resulted in the following changes from BL: MAP decreased by 34%, PP was no different, and PISFO2 decreased 40%. Heart rate remained unchanged between the three groups. The arteriolar contractile response profile to increasing concentrations of PE was right shifted, or less responsive, as tHb dropped between groups. The data indicate a robust cardiovascular compensatory response to severe hemolytic anemia, which serves to prevent peripheral tissue hypoxia. At a 75% reduction in tHb, though, this system begins to show signs of compromise as arteriolar diameters lose responsiveness to contractile stimuli and compensatory elevations in PP begin to decay. Yet, PISFO2 remains normoxic suggesting that as tHb is reduced, tissue hypoxia occurs precipitously not progressively.Support or Funding InformationSupport: Song Biotechnologies

Changes in dopamine transporter binding in nucleus accumbens following chronic self-administration cocaine: heroin combinations.

Concurrent use of cocaine and heroin (speedball) has been shown to exert synergistic effects on dopamine neurotransmission in the nucleus accumbens (NAc), as observed by significant increases in extracellular dopamine levels and compensatory elevations in the maximal reuptake rate of dopamine. The present studies were undertaken to determine whether chronic self-administration of cocaine, heroin or a combination of cocaine:heroin led to compensatory changes in the abundance and/or affinity of high- and low-affinity DAT binding sites. Saturation binding of the cocaine analog [(125) I] 3β-(4-iodophenyl)tropan-2β-carboxylic acid methyl ester ([(125) I]RTI-55) in rat NAc membranes resulted in binding curves that were best fit to two-site binding models, allowing calculation of dissociation constant (Kd ) and binding density (Bmax ) values corresponding to high- and low-affinity DAT binding sites. Scatchard analysis of the saturation binding curves clearly demonstrate the presence of high- and low- affinity binding sites in the NAc, with low-affinity sites comprising 85 to 94% of the binding sites. DAT binding analyses revealed that self-administration of cocaine and a cocaine:heroin combination increased the affinity of the low-affinity site for the cocaine congener RTI-55 compared to saline. These results indicate that the alterations observed following chronic speedball self-administration are likely due to the cocaine component alone; thus further studies are necessary to elaborate upon the synergistic effect of cocaine:heroin combinations on the dopamine system in the NAc.

Low testosterone is associated with disability in men with multiple sclerosis

Background: Gonadal steroids may modulate disease course in multiple sclerosis (MS). Objective: To assess the prevalence and clinical associations of hypogonadism in men with MS. Methods: Male patients, aged 18–65 years, with relapsing–remitting MS (RRMS) or clinically-isolated syndrome (CIS) and their first symptom < 10 years prior were selected from a longitudinal clinical study. We measured their hormones in stored morning blood samples, and collected their Expanded Disability Status Scale (EDSS) scores every 6 months and their Symbol Digit Modalities Test (SDMT) results annually. Results: Our analysis included 96 men with a mean age of 40 years, EDSS of 1.1 and disease duration of 4.6 years. Of these men, 39% were hypogonadal (total testosterone < 288 ng/dL); none showed compensatory elevations in luteinizing hormone. Their low testosterone levels and testosterone:estradiol ratios were negatively correlated with body mass index (BMI) and leptin, and showed no correlation with 25-hydroxy-vitamin D levels. In our primary cross-sectional analyses, there was a negative age-adjusted correlation between total testosterone and EDSS (p = 0.044). In the age-adjusted longitudinal analyses, higher baseline testosterone levels were associated with less decline in SDMT (p = 0.012). Conclusions: Men with MS may experience hypogonadotropic hypogonadism. Low testosterone levels may be associated with worse clinical outcomes. A potential neuroprotective role for testosterone warrants further investigation.

Comparative effect of Citrus sinensis and carbimazole on serum T4, T3 and TSH levels.

Background:There are previous independent reports on the anti-thyroid property of Citrus sinensis. This isoflavones and phenolic acid-rich natural agent is widely consumed as dietary supplement, thus the need to investigate its comparative effect with a standard anti-thyroid drug on T4, T3 and thyroid stimulating hormone (TSH) levels.Objective:To compare the effect of Citrus sinensis and carbimazole (CARB) on blood levels of thyroid hormones (T4 and T3) and TSH.Materials and Methods:Male wistar albino rats weighing 100-150 g were employed in this research. The rats were randomly assigned to four groups of seven rats per group. Group I served as control and were administered distilled water while groups II-IV were administered with 1500 mg/kg of Citrus sinensis (fresh orange juice; FOJ), 0.1 μg/g of levothyroxine (LVT) and 0.01 mg/g of CARB, respectively, per oral once daily for 28 days. The animals were sacrificed under chloroform anaesthesia and blood sample collected by cardiac puncture and processed by standard method to obtain serum. TSH, T4 and T3 were assayed with the serum using ARIA II automated radioimmunoassay instrument.Results:The results showed that TSH level was significantly (P < 0.05) decreased in LVT treated group compared with the FOJ group. T4 was significantly (P < 0.05) decreased in the FOJ and CARB groups compared with the control and LVT groups. LVT significantly increased T4 when compared with FOJ group. T3 was significantly (P < 0.05) decreased in the CARB group compared with the control.Conclusion:These findings suggest that FOJ alters thyroid hormones metabolism to reduce their serum levels with a compensatory elevations of TSH level in a direction similar to CARB.

Differential levels of brain amino acids in rat models presenting learned helplessness or non-learned helplessness

Glutamatergic and γ-aminobutyric acid (GABA)ergic abnormalities have recently been proposed to contribute to depression. The learned helplessness (LH) paradigm produces a reliable animal model of depression that expresses a deficit in escape behavior (LH model); an alternative phenotype that does not exhibit LH is a model of resilience to depression (non-LH model). We measured the contents of amino acids in the brain to investigate the mechanisms involved in the pathology of depression. LH and non-LH models were subjected to inescapable electric footshocks at random intervals following a conditioned avoidance test to determine acquirement of predicted escape deficits. Tissue amino acid contents in eight brain regions were measured via high-performance liquid chromatography. The non-LH model showed increased GABA levels in the dentate gyrus and nucleus accumbens and increased glutamine levels in the dentate gyrus and the orbitofrontal cortex. The LH model had reduced glutamine levels in the medial prefrontal cortex. Changes in the ratios of GABA, glutamine, and glutamate were detected in the non-LH model, but not in the LH model. Reductions in threonine levels occurred in the medial prefrontal cortex in both models, whereas elevated alanine levels were detected in the medial prefrontal cortex in non-LH animals. The present study demonstrates region-specific compensatory elevations in GABA levels in the dentate gyrus and nucleus accumbens of non-LH animals, supporting the implication of the GABAergic system in the recovery of depression.

Changes in the Intraocular Cytokine Levels after Intravitreal Bevacizumab in Uveitic Macular Edema

Purpose: To evaluate the changes in intraocular cytokine after intravitreal bevacizumab (IVB) for uveiticcystoid macular edema (CME).Methods: The authors evaluated 9 eyes of 8 patients who underwent IVB for uveitic CME. The aqueous humorlevels of vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β2were measured using suspension array technology at baseline and 1 month after IVB.Results: The VEGF level was decreased to insignificant level (p = .008). TGF-β2 and TNF-α levels increased significantly (p = .008 and .021, respectively). IL-6 and IL-8 showed no significant change (p = .051 and.110, respectively).Conclusion: IVB resulted in a significant decrease of VEGF levels, which was associated with anatomical improvement of CME at 1 month. Compensatory elevations of proinflammatory cytokines (IL-6 and IL-8) after selective VEGF inhibition were not observed. Marked elevation of TGF-β2 after IVB seems to play an immunosuppressive role.

Serum anti-inflammatory markers in general population subjects with elevated depressive symptoms

Anti-inflammatory substances have previously been suggested to show compensatory elevations in depressed individuals with pronounced inflammatory changes. In order to further clarify these observations, we examined depression-related alterations in the serum levels of anti-inflammatory markers interleukin (IL)-1 receptor antagonist (RA) and IL-10 and the pro-inflammatory marker IL-6 in 416 general population participants. Depression was evaluated with the Beck Depression Inventory (BDI). Participants with elevated depressive symptoms (BDI > 14, n = 44) had increased levels of IL-1 RA and IL-6. No changes were observed in their IL-10 levels. In multivariate modeling with adjustments for age, gender, obesity, regular smoking, alcohol use, metabolic syndrome, physical exercise, sleep disturbance, and the use of non-steroidal anti-inflammatory drugs, a high level of IL-1 RA was associated with an increased likelihood of belonging to the group with elevated depressive symptoms (OR for each 1 SD increase in the serum level of IL-1 RA: 2.17, 95% CI 1.35–3.48, p = 0.001). The significance of IL-6 alterations did not persist in the same model. The pronounced secretion of anti-inflammatory marker IL-1 RA may reflect the presence of compensatory mechanisms during a depression-related inflammatory state.

Chrousos syndrome: a seminal report, a phylogenetic enigma and the clinical implications of glucocorticoid signalling changes.

Glucocorticoids regulate a broad spectrum of physiologic functions and play important roles in resting and stress homeostasis. Their actions are mediated by the nuclear glucocorticoid receptor (GR). Using a patient as a stimulus, we reviewed briefly the area of Primary Generalized Glucocorticoid Resistance in man and nonhuman primates. In man, Primary Generalized Glucocorticoid Resistance is a rare sporadic or familial syndrome characterized by target-tissue insensitivity to glucocorticoids and compensatory elevations in adrenocorticotropic hormone (ACTH), leading to increased secretion of cortisol and adrenal steroids with mineralocorticoid and/or androgenic activity, and causing hypermineralocorticoidism and hyperandrogenism without Cushing stigmata. The presentation, diagnosis and therapy of this condition are summarized. Many or, most likely, all New World primates have markedly elevated cortisol and ACTH, and resistance to dexamethasone suppression, without any pathology. These primates in fact have 'pan-steroid/sterol' resistance, including all five steroid hormones and 1,25-dihydroxy-vitamin D. In humans, the molecular basis of Primary Generalized Glucocorticoid Resistance has been mainly ascribed to recent mutations in the GR gene, which impair glucocorticoid signal transduction. In contrast, in the primates, steroid/sterol signalling systems have adapted under yet unknown selective pressures or genetic drift over many million years. Of course, other molecules of the signaling pathways may also be involved in both states. There are now a host of human states associated with tissue-specific pathologic glucocorticoid target tissue changes. These include allergic, autoimmune, inflammatory and lymphoproliferative disorders. In recognition of Professor George P. Chrousos' extensive ground-breaking research in this field, and for the sake of brevity, we propose that 'Chrousos syndrome' is used instead of 'Primary Generalized Familial or Sporadic Glucocorticoid Resistance'.

A Novel Point Mutation in Helix 11 of the Ligand-Binding Domain of the Human Glucocorticoid Receptor Gene Causing Generalized Glucocorticoid Resistance

Generalized glucocorticoid resistance is a rare condition characterized by partial, end-organ insensitivity to glucocorticoids, compensatory elevations in adrenocorticotropic hormone and cortisol secretion, and increased production of adrenal steroids with androgenic and/or mineralocorticoid activity. We have identified a new case of glucocorticoid resistance caused by a novel mutation of the human glucocorticoid receptor (hGR) gene and studied the molecular mechanisms through which the mutant receptor impairs glucocorticoid signal transduction. We identified a novel, single, heterozygous nucleotide (T --> C) substitution at position 2209 (exon 9alpha) of the hGR gene, which resulted in phenylalanine (F) to leucine (L) substitution at amino acid position 737 within helix 11 of the ligand-binding domain of the protein. Compared with the wild-type receptor, the mutant receptor hGRalphaF737L demonstrated a significant ligand-exposure time-dependent decrease in its ability to transactivate the glucocorticoid-inducible mouse mammary tumor virus promoter in response to dexamethasone and displayed a 2-fold reduction in the affinity for ligand, a 12-fold delay in nuclear translocation, and an abnormal interaction with the glucocorticoid receptor-interacting protein 1 coactivator. The mutant receptor preserved its ability to bind to DNA and exerted a dominant-negative effect on the wild-type hGRalpha only after a short duration of exposure to the ligand. The mutant receptor hGRalphaF737L causes generalized glucocorticoid resistance because of decreased affinity for the ligand, marked delay in nuclear translocation, and/or abnormal interaction with the glucocorticoid receptor-interacting protein 1 coactivator. These findings confirm the importance of the C terminus of the ligand-binding domain of the receptor in conferring transactivational activity.

Novel Causes of Generalized Glucocorticoid Resistance

Glucocorticoid resistance is a rare condition characterized by generalized, partial, target-tissue insensitivity to glucocorticoids. Compensatory elevations in circulating adrenocorticotropic hormone (ACTH) concentrations lead to increased secretion of cortisol and adrenal steroids with mineralocorticoid and/or androgenic activity, but no clinical evidence of hypercortisolism. The clinical spectrum of the condition is broad, ranging from asymptomatic to severe cases of hyperandrogenism, fatigue and/or mineralocorticoid excess. The molecular basis of glucocorticoid resistance has been ascribed to mutations in the human glucocorticoid receptor (hGR) gene, which impair glucocorticoid signal transduction, thereby altering tissue sensitivity to glucocorticoids. The study of functional defects of natural hGR mutants enhances our understanding of the molecular mechanisms of hGR action and highlights the importance of integrated cellular and molecular signaling mechanisms for maintaining homeostasis and preserving normal physiology.

Interleukin-6 and platelet protagonists in T lymphocyte and virological response

The present cross-sectional study evaluated the status and relationship of interleukin-6, a platelet growth factor, with platelet counts, viral load, CD4 counts, and antiretroviral treatment in 75 HIV-infected subjects with thrombocytopenia and 50 gender-, race-, age- and antiretroviral treatment-matched controls without thrombocytopenia. Mean IL-6 production was significantly higher in thrombocytopenic participants (13 432 ± 8596) than in non-thrombocytopenic subjects (12 859 ± 3538 pg/105 Lym). Univariate analyses indicated, however, that thrombocytopenic patients were more likely to have <3000 pg of IL-6 than non-thrombocytopenic patients (OR = 7 95% CI 1.3–12; P = 0.01). For additional analyses, participants were dichotomized above and below 3000 pg of IL-6. Despite similar age, gender, drug use and antiretroviral treatment, thrombocytopenic participants had lower CD4 counts (186.5 ± 149 vs. 401 ± 286, P = 0.005) than non-thrombocytopenic subjects. Thrombocytopenic participants with elevated IL-6, with or without HAART, were more likely to have higher HIV-replication (496 273 ± 210 416; 34 656 ± 25 332) than thrombocytopenic individuals with low IL-6 levels (105 332 ± 42 699; 19 015 ± 14 296 P = 0.05). Non-thrombocytopenic patients with high IL-6 levels exhibited the highest CD4s (466.7 ± 333) and the lowest viral burden (63 094 ± 53 300) of the groups. Two distinct categories of HIV-associated thrombocytopenia exist: one accompanied by low IL-6, and another with compensatory elevations of IL-6. In thrombocytopenic individuals, the latter was associated with the poorest immunological and virological responses.

Familial/sporadic glucocorticoid resistance: clinical phenotype and molecular mechanisms.

Glucocorticoids regulate a variety of biologic processes and exert profound influences on many physiologic functions. Their actions are mediated by the glucocorticoid receptor (GR), which belongs to the nuclear receptor family of ligand-dependent transcription factors. Alterations in tissue sensitivity to glucocorticoids may manifest as states of resistance or hypersensitivity. Glucocorticoid resistance is a rare, familial or sporadic, condition characterized by generalized, partial target-tissue resistance to glucocorticoids. Compensatory elevations in circulating adrenocorticotropic hormone (ACTH) concentrations lead to increased production of adrenal steroids with mineralocorticoid and/or androgenic activity and their corresponding clinical manifestations, as well as increased urinary free-cortisol excretion in the absence of symptomatology suggestive of hypercortisolism. The molecular basis of the condition has been ascribed to mutations in the GR gene, which impair normal glucocorticoid signal transduction, altering tissue sensitivity to glucocorticoids. The present review focuses on the mechanisms of GR action and the clinical manifestations and molecular mechanisms of familial/sporadic glucocorticoid resistance.

Nicotine is a neurotoxin in the adolescent brain: critical periods, patterns of exposure, regional selectivity, and dose thresholds for macromolecular alterations

In the fetus, nicotine is a neuroteratogen that elicits cell damage and loss and subsequent abnormalities of synaptic function. We explored whether these effects extend into adolescence, the period when most people begin smoking. Beginning on postnatal day 30, rats were given a 1 week regimen of nicotine infusions or twice-daily injections, at doses (0.6, 2 and 6 mg/kg/day) set to achieve plasma levels found in occasional to regular smokers. We assessed indices of cell packing density and cell number (DNA concentration and content), cell size (total protein/DNA ratio) and neuritic projections (membrane/total protein) in the midbrain, hippocampus and cerebral cortex, three regions known to be vulnerable to developmental effects of nicotine. With either route of administration, nicotine evoked shortfalls in DNA concentration and content, compensatory elevations of total protein/DNA, and reductions in the membrane/total protein ratio. Nearly all of the effects were apparent even at the lowest dose of nicotine and remained fully evident 1 month posttreatment. Although both males and females showed significant alterations, in general the effects were larger in females. Our results indicate that in adolescence, even a brief period of continuous or intermittent nicotine exposure, elicits lasting alterations in biomarkers associated with cellular and neuritic damage. As the effects are detected at exposures that produce plasma concentrations one-tenth of those in regular smokers, the exquisite sensitivity of the adolescent brain to nicotine neurotoxicity may contribute to lasting neurobehavioral damage even in occasional smokers.