Prolonged exposure to glucocorticoids in pharmacologic amounts results in muscle wasting, but whether changes in plasma cortisol within the physiologic range affect amino acid and protein metabolism in man has not been determined. To determine whether a physiologic increase in plasma cortisol increases proteolysis and the de novo synthesis of alanine, seven normal subjects were studied on two occasions during an 8-h infusion of either hydrocortisone sodium succinate (2 micrograms/kg X min) or saline. The rate of appearance (Ra) of leucine and alanine were estimated using [2H3]leucine and [2H3]alanine. In addition, the Ra of leucine nitrogen and the rate of transfer of leucine nitrogen to alanine were estimated using [15N]leucine. Plasma cortisol increased (10 +/- 1 to 42 +/- 4 micrograms/dl) during cortisol infusion and decreased (14 +/- 2 to 10 +/- 2 micrograms/dl) during saline infusion. No change was observed in plasma insulin, C-peptide, or glucagon during either saline or cortisol infusion. Plasma leucine concentration increased more (P less than 0.05) during cortisol infusion (120 +/- 1 to 203 +/- 21 microM) than saline (118 +/- 8 to 154 +/- 4 microM) as a result of a greater (P less than 0.01) increase in its Ra during cortisol infusion (1.47 +/- 0.08 to 1.81 +/- 0.08 mumol/kg X min for cortisol vs. 1.50 +/- 0.08 to 1.57 +/- 0.09 mumol/kg X min). Leucine nitrogen Ra increased (P less than 0.01) from 2.35 +/- 0.12 to 3.46 +/- 0.24 mumol/kg X min, but less so (P less than 0.05) during saline infusion (2.43 +/- 0.17 to 2.84 +/- 0.15 mumol/kg X min, P less than 0.01). Alanine Ra increased (P less than 0.05) during cortisol infusion but remained constant during saline infusion. During cortisol, but not during saline infusion, the rate and percentage of leucine nitrogen going to alanine increased (P less than 0.05). Thus, an increase in plasma cortisol within the physiologic range increases proteolysis and the de novo synthesis of alanine, a potential gluconeogenic substrate. Therefore, physiologic changes in plasma cortisol play a role in the regulation of whole body protein and amino acid metabolism in man.

1. Mechanisms of ion transport across the choroidal epithelium were investigated using an in vitro preparation of the frog choroid plexus.2. Sodium was actively transported across the plexus from the vascular to the ventricular surface by an ouabain sensitive electrically silent pump. As in other epithelial membranes the rate of sodium transport was stimulated by the presence of bicarbonate ions in the Ringer solutions. Chloride and bicarbonate ions accompany the net flux of sodium across this tissue.3. Some experiments suggest that potassium is actively transported from the ventricular to the serosal surface, and that the rate of transport is a function of the extracellular potassium concentration.4. No evidence was obtained to suggest that calcium is actively transported across this tissue in either direction.5. Diamox, ethoxyzolamide, pitocin, pitressin, hydrocortisone, amiloride, spironolactone and anoxia all failed to influence sodium transport.6. The sequence of passive ion permeation across the plexus was P(Rb) approximately P(K)>> P(Cs) approximately P(Na) approximately P(Cl) approximately P(HCO3)>> P(Li) as deduced from diffusion potential measurements. At least for Na, K and Cl there was a good correlation between the permeability coefficients derived from unidirectional flux measurements and from electrical parameters. This indicates that exchange diffusion is unimportant as a mechanism for passive ion transport.7. The instantaneous current-voltage curves were linear in both symmetrical and asymmetrical salt solutions and the choroid plexus conductance was found to be directly proportional to the external salt concentration. These and other lines of evidence suggest that the major route of passive ion permeation across this epithelium is via the tight junction route and not through the cell interior.8. These results are discussed in relation to the in vivo studies of c.s.f. secretion and the mechanisms of active and passive ion transport across other epithelial membranes such as the gall-bladder, intestine and renal proximal tubule.

Using mouse mammary epithelial cells (MME) as a model, we show that extracellular matrix (ECM) plays a fundamental role in the maintenance of tissue-specific function in culture. The ECM affects both the level of mRNA and the rates of synthesis and secretion of milk proteins. Casein gene expression by primary mammary epithelial cells and cell strains is controlled by both ECM and lactogenic hormones (insulin, hydrocortisone and prolactin). In the case of transferrin, the major iron-binding protein of mouse milk, the ECM rather than prolactin, appears to modulate the level of its mRNA. We further show that both ECM and lactogenic hormones influence cell shape and polarity of mammary epithelial cells. The data are consistent with a model of "Dynamic Reciprocity" (Bissell et al. 1982) where the ECM is postulated to exert an influence on gene expression via transmembrane proteins and cytoskeletal components. Cytoskeleton, in turn, is associated with polyribosomes, affecting mRNA stability and rates of protein synthesis, and with the nuclear matrix, affecting mRNA processing and, possibly, rates of transcription. We postulate that hormones and ECM act synergistically to complete the 'reciprocity' loop.

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) often colonize the anterior nares, and nasal carriage remains the main source of bacterial dissemination. The aim of this study was to assess the in vivo activity of the lantibiotic mersacidin against MRSA colonizing nasal epithelia.

METHODS

The efficiency of mersacidin in the eradication of MRSA was tested employing mice pre-treated with hydrocortisone and inoculated intranasally either three or six times with a bacterial suspension.

RESULTS

In mersacidin-treated animals, pre-colonized with MRSA, bacteria could not be detected in blood, lungs, liver, kidney, spleen or nasal scrapings and there were no lesions manifested after intraperitoneal drug application. Blood samples from infected mice obtained 2 h after mersacidin therapy revealed anti-MRSA activity in a serum bactericidal test. Moreover, elevated interleukin-1beta and tumour necrosis factor-alpha titres were noticed in the pre-infected but not in cured animals. In contrast, mersacidin did not induce differences in the cytokine profiles of treated uninfected control mice.

CONCLUSIONS

In the mouse rhinitis model, mersacidin was able to eradicate MRSA colonization. The site of action (epithelium versus blood) of mersacidin needs to be further explored.

Neutrophils are important cellular mediators in inflammatory bowel disease (IBD). Interleukin (IL)8, a powerful neutrophil chemoattractant, is found in increased quantities in inflamed mucosa, but the cells of origin are uncertain. IL8 gene expression was studied by in situ hybridisation in uninflamed intestinal tissue resected for colon carcinoma (n = 7) and in inflamed colonic tissue resected for IBD (n = 11). Immunohistochemistry was used to assess the phenotype of IL8 expressing macrophages and the production of IL8 protein. Macrophages isolated from intestinal resections and lipopolysaccharide stimulated peripheral blood monocytes treated with 5-aminosalicylic acid, hydrocortisone, and cyclosporin A were examined for IL8 mRNA by northern blotting and IL8 secretion by enzyme linked immunosorbent assay (ELISA). In all cases IL8 mRNA was detected by in situ hybridisation in macrophages and neutrophils adjacent to ulceration in inflamed bowel, but not detected in uninflamed mucosa from carcinoma resections. Recently recruited CD14 positive macrophages were responsible for some of this IL8 expression. IL8 protein was present in the same distribution as mRNA. Epithelial cells in normal and inflamed tissue showed neither mRNA nor protein. IL8 mRNA was expressed significantly more commonly by macrophages from IBD affected than from normal mucosa, and IL8 secretion by IBD but not normal colon macrophages was augmented significantly by lipopolysaccharide treatment. IL8 expression and production by lipopolysaccharide treated blood monocytes was inhibited by the therapeutic agents tested. These results show that neutrophils and recently recruited macrophages are responsible for production of IL8 in IBD, suggesting a mechanism for a continuing cycle of neutrophil attraction. Agents used therapeutically in these diseases may be effective in part by disrupting this cycle.

BACKGROUND

Severe systemic infection leads to hypercortisolism. Reduced cortisol binding proteins may accentuate the free cortisol elevations seen in systemic infection. Recently, low total cortisol increments after tetracosactrin have been associated with increased mortality and hemodynamic responsiveness to exogenous hydrocortisone in septic shock (SS), a phenomenon termed by some investigators as relative adrenal insufficiency (RAI).

OBJECTIVE

Free plasma cortisol may correspond more closely to illness severity than total cortisol, comparing SS and sepsis (S).

METHODS

This was a prospective study.

METHODS

This study took place in a tertiary teaching hospital.

METHODS

Patients had SS (n = 45) or S (n = 19) or were healthy controls (HCs; n = 10).

OBJECTIVE

The aim of the study was to compare total with free cortisol, measured directly and estimated by Coolens' method, corticosteroid-binding globulin (CBG), and albumin in patients with SS (with and without RAI) and S during acute illness, recovery, and convalescence.

RESULTS

Comparing SS, S, and HC subjects, free cortisol levels reflected illness severity more closely than total cortisol (basal free cortisol, SS, 186 vs. S, 29 vs. HC, 13 nmol/liter, P < 0.001 compared with basal total cortisol, SS, 880 vs. S, 417 vs. HC, 352 nmol/liter, P < 0.001). Stimulated free cortisol increments varied greatly with illness category (SS, 192 vs. S, 115 vs. HC, 59 nmol/liter, P = 0.004), whereas total cortisol increments did not (SS, 474 vs. S, 576 vs. HC, 524 nmol/liter, P = 0.013). The lack of increase in total cortisol with illness severity is due to lower CBG and albumin. One third of patients with SS (15 of 45) but no S patients met a recently described criterion for RAI (total cortisol increment after tetracosactrin < or = 248 nmol/liter). RAI patients had higher basal total cortisol (1157 vs. 756 nmol/liter; P = 0.028) and basal free cortisol (287 vs. 140 nmol/liter; P = 0.017) than non-RAI patients. Mean cortisol increments in RAI were lower (total, 99 vs. 648 nmol/liter, P < 0.001; free, 59 vs. 252 nmol/liter, P < 0.001). These differences were not due to altered CBG or albumin levels. Free cortisol levels normalized more promptly than total cortisol in convalescence. Calculated free cortisol by Coolens' method compared closely with measured free cortisol.

CONCLUSIONS

Free cortisol is likely to be a better guide to cortisolemia in systemic infection because it corresponds more closely to illness severity. The attenuated cortisol increment after tetracosactrin in RAI is not due to low cortisol-binding proteins. Free cortisol levels can be determined reliably using total cortisol and CBG levels.

OBJECTIVE

Rheumatoid arthritis (RA) is classically thought of as a Th1, T lymphocyte-driven disease of the adaptive immune system. However, cells of the innate immune system, including neutrophils, are prevalent within the diseased joint, and accumulate in large numbers. This study was undertaken to determine whether cells of the rheumatoid stromal microenvironment could establish an inflammatory environment in which endothelial cells are conditioned in a disease-specific manner to support neutrophil recruitment.

METHODS

Human umbilical vein endothelial cells (ECs) and fibroblasts isolated from the synovium or skin of RA patients were established in coculture on opposite sides of porous transwell filters. After 24 hours of EC conditioning, the membranes were incorporated into a parallel-plate, flow-based adhesion assay and levels of neutrophil adhesion to ECs were measured.

RESULTS

ECs cocultured with synovial, but not skin, fibroblasts could recruit neutrophils in a manner that was dependent on the number of fibroblasts. Antibody blockade of P-selectin or E-selectin reduced neutrophil adhesion, and an antibody against CD18 (the beta2 integrin) abolished adhesion. Blockade of CXCR2, but not CXCR1, also greatly inhibited neutrophil recruitment. Interleukin-6 (IL-6) was detectable in coculture supernatants, and both IL-6 and neutrophil adhesion were reduced in a dose-dependent manner by hydrocortisone added to cocultures. Antibody blockade of IL-6 also effectively abolished neutrophil adhesion.

CONCLUSIONS

Synovial fibroblasts from the rheumatoid joint play an important role in regulating the recruitment of inflammatory leukocytes during active disease. This process may depend on a previously unsuspected route of IL-6-mediated crosstalk between fibroblasts and endothelial cells.

The antagonism between analgesic antipyretic drugs and bradykinin was examined quantitatively, using the bronchoconstrictor response of guinea-pigs in vivo. The dose of bradykinin required to overcome antagonism by calcium acetylsalicylate increased with the dose of acetylsalicylate given, the ratio being roughly constant. Fifty times the quantity of acetylsalicylate which just antagonized bradykinin did not modify bronchoconstriction due to small doses of histamine, 5-hydroxytryptamine, or acetylcholine. A method of measuring the potency of this anti-bradykinin action was developed. Acetylsalicylic acid, phenylbutazone, amidopyrine, and phenazone had a high potency; paracetamol, cinchophen, sodium salicylate, and acetanilide had a moderate potency; and phenacetin, salicylamide, and 4-hydroxyisophthalic acid had little or none. Cortisone, hydrocortisone, aldosterone, amodiaquine, and morphine were ineffective or their action was non-specific. In sensitized guinea-pigs, an injection of antigen caused bronchospasm. This response was greatly lessened by pretreatment with mepyramine, but was not affected by calcium acetylsalicylate, lysergic acid diethylamide, or atropine. Acetylsalicylic acid, phenylbutazone, and amidopyrine did not specifically antagonize the action of bradykinin on the capillaries of guinea-pig skin in vivo, on guinea-pig ileum in vitro or on rat duodenum in vitro.

Although the first fibroblast growth factor (FGF) was discovered as a mitogen on 3T3 fibroblasts [Gospodarowicz D: Localization of a fibroblast growth factor and its effect alone and with hydrocortisone on 3T3 cell growth. Nature 1974, 249:123-127], this name is functionally misleading. This group of secreted proteins consisting now of 22 members was composed based on common structural characteristics rather than on functional similarity. Thus, only a few members of the human FGF family promote growth and strictly act on fibroblasts. While the research in the last century firmly established FGFs as key players in development, morphogenesis, angiogenesis, hematopoiesis, and survival, this decade provided clues on FGF roles in metabolism. In particular, 'hormone-like' FGF19, FGF21, and FGF23, were shown to be involved in glucose, lipid, bile acid, phosphate, and vitamin D metabolism but the mechanisms underlying their functions as metabolic regulators are still being defined.

A prospective double blind controlled trial was undertaken to examine the role of metronidazole as an adjunct to corticosteroids in the management of severe ulcerative colitis. Thirty nine patients with severe ulcerative colitis were randomised on admission to hospital to receive either intravenous metronidazole 500 mg eight hourly (19 patients) or an identical intravenous placebo (20 patients). The two groups were similar with respect to age, sex, and the extent of colitis. In addition all patients received a standard intravenous regimen consisting of methyl prednisolone 16 mg six hourly and parenteral nutrition together with a twice daily hydrocortisone 100 mg enema. Treatment was continued for five days when the patients were formally assessed. Fourteen of 19 patients (74%) receiving metronidazole and 14/20 (70%) receiving placebo were substantially improved, or in remission at the end of five days. Five patients treated with metronidazole and six with placebo had no improvement and all proceeded to urgent colectomy with no operative mortality. There were three late deaths, one in the metronidazole and two in the placebo group. These results do not support the routine use of intravenous metronidazole in the treatment of severe ulcerative colitis.

Lymphocyte kinetic studies employing 51-chromium-labeled autologous lymphocytes were performed in nine normal volunteers in order to determine the effects of hydrocortisone administration on the recirculating versus the nonrecirculating intravascular lymphocyte pools. Following infusion of labeled cells, the recirculating portion of the labeled cells rapidly equilibrated with the total intravascular lymphocyte pool and the vastly larger total-body recirculating lymphocyte pool, so that by 1 hr following infusion 21.8% plus or minus 3.2% of the labeled lymphocytes were left in the circulation. Four hundred milligrams of intravenous hydrocortisone administered 24 hr after infusion of labeled cells caused a profound but transient lymphocytopenia which was maximal at 4 hr with return of lymphocyte counts to normal by 24 hr after injection. Concomitant with the lymphocytopenia there was a dramatic increase in lymphocyte specific activity (cpm per 10-6 lymphocytes), while the total lymphocyte-associated radioactivity remaining in the circulation was unchanged, indicating that corticosteroid administration depleted the unlabeled recirculating cells. As the lymphocyte counts returned to normal following hydrocortisone, the specific activity also returned to normal. These studies indicated that hydrocortisone administration caused a transient lymphocytopenia by a preferential depletion of the recirculating portion of the intravascular lymphocyte pool

Acute stress is associated with a sensitized amygdala. Corticosteroids, released in response to stress, are suggested to restore homeostasis by normalizing/desensitizing brain processing in the aftermath of stress. Here, we investigated the effects of corticosteroids on amygdala processing using functional magnetic resonance imaging. Since corticosteroids exert rapid nongenomic and slow genomic effects, we administered hydrocortisone either 75 min (rapid effects) or 285 min (slow effects) before scanning in a randomized, double-blind, placebo-controlled design. Seventy-two healthy males were scanned while viewing faces morphing from a neutral facial expression into fearful or happy expressions. Imaging results revealed that hydrocortisone desensitizes amygdala responsivity rapidly, while it selectively normalizes responses to negative stimuli slowly. Psychophysiological interaction analyses suggested that this slow normalization is related to an altered coupling of the amygdala with the medial prefrontal cortex. These results reveal a temporarily fine-tuned mechanism that is critical for avoiding amygdala overshoot during stress and enabling adequate recovery thereafter.

B chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of slow-dividing and long-lived monoclonal B cells arrested at the intermediate stage of their differentiation. We previously showed that interleukin 4 (IL-4) not only inhibits but also prevents the proliferation of B-CLL cells. We report here that IL-4 protects the B-CLL cells from death by apoptosis (programmed cell death [PCD]). IL-4 inhibits spontaneous and hydrocortisone (HC)-induced PCD of highly purified B cells from 12 unselected CLL patients, as shown by sustained cell viability and lack of DNA fragmentation. IL-1, -2, -3, -5, -6, -7, tumor necrosis factor alpha, and transforming growth factor beta have no protective effect. The in vitro rescue from apoptosis by IL-4 is reflected by an increased expression of Bcl-2 protein, a proto-oncogene directly involved in the prolongation of cell survival in vivo and in vitro. Hence, IL-4-treated B-CLL cells express significantly more Bcl-2 than unstimulated, HC-treated, or fresh B-CLL cells. Furthermore, subcutaneous injection of IL-4 into one CLL patient enhances Bcl-2 protein expression in the leukemic B cells. These data may suggest that IL-4 prevents apoptosis of B-CLL cells using a Bcl-2-dependent pathway. Given our recent observations that fresh T cells from B-CLL patients express IL-4 mRNA, we propose that IL-4 has an essential role in the pathogenesis of CLL disease, by preventing both the death and the proliferation of the malignant B cells.

We investigated whether plasticity of human motor cortex (M1) is influenced by time of day, and whether changes in circulating levels of cortisol contribute to this effect. Neuroplasticity was induced using paired associative stimulation (PAS), involving electrical stimulation of left median nerve, paired with transcranial magnetic stimulation over the right M1 25 ms later (90 pairs at 0.05 Hz). Surface EMG was recorded from the left abductor pollicis brevis (APB) and first dorsal interosseous muscle. Cortisol levels were assessed from saliva. Time-of-day modulation of PAS effectiveness was assessed in 25 subjects who were tested twice, at 8:00 A.M. and 8:00 P.M. on separate days. In a second double-blind study, 17 subjects were tested with PAS at 8:00 P.M. on two occasions after administration of oral hydrocortisone (24 mg) or placebo. The motor-evoked potential (MEP) in resting APB increased significantly after PAS in the evening (when endogenous cortisol levels were low), but not in the morning. Oral hydrocortisone prevented facilitation of the APB MEP after PAS, and in the drug study, mean salivary cortisol levels were negatively associated with PAS effectiveness. The GABA(B)-mediated cortical silent period for APB was longer in the morning than in the evening, and was lengthened by PAS and oral hydrocortisone. We conclude that neuroplasticity in human M1 and GABA(B)-dependent intracortical inhibitory systems are influenced by time of day and modified by circulating levels of cortisol.

We report on the production of hydrocortisone, the major adrenal glucocorticoid of mammals and an important intermediate of steroidal drug synthesis, from a simple carbon source by recombinant Saccharomyces cerevisiae strains. An artificial and fully self-sufficient biosynthetic pathway involving 13 engineered genes was assembled and expressed in a single yeast strain. Endogenous sterol biosynthesis was rerouted to produce compatible sterols to serve as substrates for the heterologous part of the pathway. Biosynthesis involves eight mammalian proteins (mature forms of CYP11A1, adrenodoxin (ADX), and adrenodoxin reductase (ADR); mitochondrial forms of ADX and CYP11B1; 3beta-HSD, CYP17A1, and CYP21A1). Optimization involved modulating the two mitochondrial systems and disrupting of unwanted side reactions associated with ATF2, GCY1, and YPR1 gene products. Hydrocortisone was the major steroid produced. This work demonstrates the feasibility of transfering a complex biosynthetic pathway from higher eukaryotes into microorganisms.

OBJECTIVE

This study examined whether chronic interpersonal stress is associated with cellular markers of inflammation and regulation of these responses by in vitro doses of glucocorticoids in rheumatoid arthritis (RA) patients. The association between these markers of inflammation and fatigue was also tested.

METHODS

Fifty-eight RA patients completed up to 30 daily ratings of the stressfulness of their interpersonal relations. Interleukin-6 (IL-6) production was analyzed in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cell cultures with and without varying concentrations of the glucocorticoid hydrocortisone. In addition, plasma levels of IL-6 and C-reactive protein (CRP) were analyzed, and subjective ratings of fatigue and pain were obtained on the day of blood sampling.

RESULTS

Multilevel modeling showed that higher chronic interpersonal stress was associated with greater stimulated IL-6 production (p<0.05) as well as greater resistance to hydrocortisone inhibition of IL-6 production (p<0.05). These relations were not accounted for by demographic factors, body mass index, or steroid medication use. Stimulated production of IL-6, in turn, was associated with greater levels of self-reported fatigue, controlling for pain (p<0.05). Neither chronic stress ratings nor fatigue symptoms were related to plasma levels of IL-6 or CRP (ps>.05).

CONCLUSIONS

Among RA patients, chronic interpersonal stress is associated with greater stimulated cellular production of IL-6 along with impairments in the capacity of glucocorticoids to inhibit this cellular inflammatory response. Moreover, these findings add to a growing body of data that implicate heightened proinflammatory cytokine activity in those at risk for fatigue symptoms.

Caco-2 cells, which express spontaneous enterocytic differentiation at confluency, is one of the most relevant in vitro models for the study of differentiation and regulation of intestinal functions. However, these cells are normally cultured in the presence of 15-20% serum which renders extremely complex the identification of the factors involved in the regulation of both proliferation and differentiation. This study has been devoted to the establishment of chemically defined culture conditions which can sustain growth and differentiation of Caco-2 cells. The replacement of serum by ITS (insulin, transferrin, and selenium) allowed for normal structural and functional differentiation of cells as revealed by the establishment of cell polarity and the expression of brush-border membrane enzyme markers (sucrase, maltase, lactase, alkaline phosphatase, gamma-glutamyltransferase, aminopeptidase N, and dipeptidyl-dipeptidase IV), although the levels of sucrase activity were lower in ITS-supplemented medium. Coating petridishes with either type IV collagen or basement membrane proteins (Matrigel) did not improve the differentiation of cells, brush-border membrane enzyme activities being, in fact, lower when the cells were grown on these substrata. When triiodothyronine (T3, 5 x 10(-8) M) was added to the ITS-supplemented medium, disaccharidase and alkaline phosphatase activities were significantly increased while gamma-glutamyltransferase activity was diminished by T3 and stimulated by epidermal growth factor (1.6 x 10(-6) M). On the other hand, hydrocortisone (HC, 10(-6) M) did not modify disaccharidase and peptidase activities. These data clearly show that Caco-2 cells can be maintained in serum-free medium and that this system allows the study of the factors involved in the regulation of the differentiation of enterocyte in vitro.

Primary cultures of baby mouse kidney epithelial cells can grow without fibroblast overgrowth in a hormone-supplemented serum-free medium (Medium K-1) designed for an established kidney epithelial cell line, MDCK. The five supplements in Medium K-1 are insulin, transferrin, PGE1, T3, and hydrocortisone. Medium K-1 also supports the growth of kidney epithelial cell cultures from a number of animals, including man, without fibroblast overgrowth. Outgrowth of kidney epithelial cells from kidney explants was also observed with Medium K-1. Thus, the medium appears to be selective for epithelial cell growth. The physiological properties of primary cultures of baby mouse kidney epithelial cells were studied in detail. Baby mouse kidney epithelial cells grew at equal rates (0.5 doublings/day) in Medium K-1 and serum-supplemented medium. Medium K-1 also supported the formation of baby mouse kidney epithelial colonies at low cell densities. The dependence of baby mouse kidney epithelial colony formation upon the five factors in Medium K-1 was examined. These studies indicated that the formation of baby mouse kidney epithelial colonies in defined medium depended upon all the five supplements in Medium K-1, in a manner similar, although not identical, to MDCK colonies. Primary cultures of baby mouse kidney epithelial cells grown in Medium K-1 retained kidney cell-associated properties, including the ability to form multicellular domes, a phenomenon associated with transepithelial salt transport. Amiloride-sensitive Na+ uptake and the mucosal surface enzyme leucine aminopeptidase were also observed in baby mouse kidney cultures. Similar functions were observed in MDCK monolayers.

OBJECTIVE

Circulating cortisol fluctuates diurnally under the control of the "master" circadian CLOCK, while the peripheral "slave" counterpart of the latter regulates the transcriptional activity of the glucocorticoid receptor (GR) at local glucocorticoid target tissues through acetylation. In this manuscript, we studied the effect of CLOCK-mediated GR acetylation on the sensitivity of peripheral tissues to glucocorticoids in humans.

METHODS

We examined GR acetylation and mRNA expression of GR, CLOCK-related and glucocorticoid-responsive genes in peripheral blood mononuclear cells (PBMCs) obtained at 8 am and 8 pm from 10 healthy subjects, as well as in PBMCs obtained in the morning and cultured for 24 hours with exposure to 3-hour hydrocortisone pulses every 6 hours. We used EBV-transformed lymphocytes (EBVLs) as non-synchronized controls.

RESULTS

GR acetylation was higher in the morning than in the evening in PBMCs, mirroring the fluctuations of circulating cortisol in reverse phase. All known glucocorticoid-responsive genes tested responded as expected to hydrocortisone in non-synchronized EBVLs, however, some of these genes did not show the expected diurnal mRNA fluctuations in PBMCs in vivo. Instead, their mRNA oscillated in a Clock- and a GR acetylation-dependent fashion in naturally synchronized PBMCs cultured ex vivo in the absence of the endogenous glucocorticoid, suggesting that circulating cortisol might prevent circadian GR acetylation-dependent effects in some glucocorticoid-responsive genes in vivo.

CONCLUSIONS

Peripheral CLOCK-mediated circadian acetylation of the human GR may function as a target-tissue, gene-specific counter regulatory mechanism to the actions of diurnally fluctuating cortisol, effectively decreasing tissue sensitivity to glucocorticoids in the morning and increasing it at night.

OBJECTIVE

There is much concern about potential neurodevelopmental impairment after neonatal corticosteroid treatment for chronic lung disease. Dexamethasone is the corticosteroid most often used in this clinical setting, and it has been shown to impair cortical growth among preterm infants. This study evaluated long-term effects of prematurity itself and of neonatal hydrocortisone treatment on structural and functional brain development using three-dimensional MRI with advanced image-processing and neurocognitive assessments.

METHODS

Sixty children born preterm, including 25 children treated with hydrocortisone and 35 children not treated with hydrocortisone, and 21 children born at term were evaluated, at a mean age of 8 years, with quantitative MRI and neurocognitive assessments (Wechsler Intelligence Scales for Children-Revised [WISC-R]). Automatic image segmentation was used to determine the tissue volumes of cerebral gray matter, white matter, and cerebrospinal fluid. In addition, the volume of the hippocampus was determined manually. WISC-R scores were recorded as mean intelligence scores at evaluation. Neonatal hydrocortisone treatment for chronic lung disease consisted of a starting dose of 5 mg/kg per day tapered over a minimum of 3 weeks.

RESULTS

Cerebral gray matter volume was reduced among preterm children (regardless of hydrocortisone treatment), compared with children born at term (preterm: 649 +/- 4.4 mL; term: 666 +/- 7.3 mL). Birth weight was shown to correlate with gray matter volume at 8 years of age in the preterm group (r = 0.421). Cerebrospinal fluid volume was increased among children born preterm, compared with children born at term (preterm: 228 +/- 4.9 mL; term: 206 +/- 8.2 mL). Total hippocampal volume tended to be lower among children born preterm, with a more pronounced reduction of hippocampal volume among boys (preterm: 6.1 +/- 0.13 mL; term: 6.56 +/- 0.2 mL). The WISC-R score was lower for children born preterm, compared with children born at term (preterm: 99.4 +/- 12.4; term: 109.6 +/- 8.8). Children treated with neonatal hydrocortisone had very similar volumes of gray matter (preterm with hydrocortisone: 650 +/- 7.0 mL; preterm without hydrocortisone: 640 +/- 5.6 mL), white matter (preterm with hydrocortisone: 503 +/- 6.1 mL; preterm without hydrocortisone: 510 +/- 4.9 mL), and cerebrospinal fluid (preterm with hydrocortisone: 227 +/- 7.4 mL; preterm without hydrocortisone: 224 +/- 6.0 mL), compared with untreated infants. The hippocampal volumes were similar in the 2 groups (preterm with hydrocortisone: 5.92 +/- 0.15 mL; preterm without hydrocortisone: 5.81 +/- 0.12 mL). The WISC-R score assessments were within the normal range for both groups, with no difference between the groups (preterm with hydrocortisone: 100.8 +/- 13; preterm without hydrocortisone: 98.6 +/- 12.3).

CONCLUSIONS

Prematurity is associated with mild brain structural differences that persist at 8 years of age, with associated lower scores in neurocognitive assessments. The data suggest that perinatal hydrocortisone given at the described dosage has no long-term effects on either neurostructural brain development or neurocognitive outcomes.

BACKGROUND

Hypopituitary patients with untreated GH deficiency and patients on inappropriately high doses of glucocorticoid (GC) share certain clinical features.

OBJECTIVE

The aim of the study was to examine the influence of GC substitution on clinical characteristics in hypopituitary patients before and after GH replacement therapy.

METHODS

A total of 2424 hypopituitary patients within the KIMS (Pfizer International Metabolic Database) were grouped according to ACTH status. Comparisons were performed between subjects on hydrocortisone (HC) (n = 1186), cortisone acetate (CA) (n = 487), and prednisolone/dexamethasone (n = 52), and ACTH-sufficient patients (AS) (n = 717) before and after 1 yr of GH treatment in terms of body mass index, waist and hip circumference, blood pressure, glucose, glycosylated hemoglobin (HbA1c), serum lipids, IGF-I, and comorbidity. Hydrocortisone equivalent (HCeq) doses were calculated, and measurements were adjusted for sex and age.

RESULTS

At baseline, the HC group had increased total cholesterol, triglycerides, waist circumference, and HbA1c, and the prednisolone/dexamethasone group had increased waist/hip ratio as compared with AS. After HCeq dose adjustment, the HC group retained higher HbA1c than the CA group. GC-treated patients showed a dose-related increase in serum IGF-I, body mass index, triglycerides, low-density lipoprotein cholesterol and total cholesterol levels. Subjects with HCeq doses less than 20 mg/d (n = 328) at baseline did not differ from AS in metabolic endpoints. The 1-yr metabolic response to GH was similar in all GC groups and dose categories. All new cases of diabetes (n = 12), stroke (n = 8), and myocardial infarction (n = 3) during GH treatment occurred in GC-treated subjects.

CONCLUSIONS

HCeq doses of at least 20 mg/d in adults with hypopituitarism are associated with an unfavorable metabolic profile. CA replacement may have metabolic advantages compared with other GCs.

Vigabatrin has been shown to be efficient in infants with infantile spasms and tuberous sclerosis, in open studies. In order to compare vigabatrin to oral steroids, a prospective randomized multicenter study was implemented using both drugs as monotherapy in newly diagnosed patients with infantile spasms and tuberous sclerosis. Eleven infants received vigabatrin (150 mg/kg per day) and 11 hydrocortisone (15 mg/kg per day) for 1 month. Spasm free patients continued vigabatrin or progressively stopped hydrocortisone in 1 month, non-responders were crossed to the other drug for a new 2 month-period. All vigabatrin patients (11/11) were spasm-free versus 5/11 hydrocortisone infants (P < 0.01). Seven patients were crossed to vigabatrin (six for inefficacy, one for adverse events) and became also totally controlled. Mean time to disappearance of infantile spasms was 3.5 days on vigabatrin versus 13 days on hydrocortisone (P < 0.01). Five patients exhibited side effects on vigabatrin but nine on hydrocortisone (P = 0.006). Vigabatrin should therefore be considered as the first choice treatment for infantile spasms due to tuberous sclerosis.

Mammalian circadian organization is governed by pacemaker neurons in the brain that communicate with oscillators in peripheral tissues. Adrenal glucocorticoids are important time-giving signals to peripheral circadian oscillators. We investigated the rhythm of Per1-luc expression in pineal, pituitary, salivary glands, liver, lung, kidney, cornea as well as suprachiasmatic nucleus from adrenalectomized and sham-operated rats kept under light-dark cycles, or exposed to single 6-h phase delays or advances of their light cycles. Adrenalectomy shifted the phases of Per1-luc in liver, kidney, and cornea and caused phase desynchrony and significant dampening in the rhythmicity of cornea. Treatment with hydrocortisone shifted the phases of Per1-luc in most of the tissues examined, even those that were not affected by adrenalectomy. The rhythm in cornea recovered in animals given hydrocortisone in vivo or when corneas were treated with dexamethasone in vitro. Adrenalectomy increased the rate of reentrainment after phase shifts in liver, kidney, cornea, pineal, lung, and suprachiasmatic nucleus but not in pituitary and salivary glands. Our data show that glucocorticoids act as strong entraining signals for peripheral circadian oscillators and may feed back on central oscillators as well.

Patients with postinfective irritable bowel syndrome and Trichinella spiralis-infected mice share many features including visceral hypersensitivity and disordered motility. We assessed enterochromaffin (EC) numbers and serotonin transporter (SERT) using National Institute of Health (NIH) female mice studied for up to 56 days post-T. spiralis infection. The effects of steroid treatment and the T-cell dependence of the observed responses were assessed by infection of hydrocortisone-treated or T-cell receptor knock out [TCR (betaxdelta) KO] animals. Enterochromaffin cell density in uninfected animals increased from duodenum 10.0 cells mm-2 (5.9-41.0) to colon 61.8. (46.3-162) cells mm-2 P<0.0001. Infection increased duodenal and jejunal counts which rose to 37.3 (22-57.7) cells mm-2 and 50.6 (7-110.8) cells mm-2, respectively, at day 14. Infection significantly reduced jejunal SERT expression, with luminance values falling from 61.0 (45.1-98.3) to a nadir of 11.6 (0-36.0) units at day 9, P<0.001. Specific deficiencies in all T cells reduced EC hyperplasia and abrogated infection-induced mastocytosis. Thus infection induced inflammation increases EC numbers, as has been reported in PI-IBS, and reduces SERT. This may increase mucosal 5HT availability and contribute to the clinical presentation of PI-IBS.