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At least 163 records · Page 9Linked to original sources

PubMed2007

Salivary cortisol in preterm infants: Validation of a simple method for collecting saliva for cortisol determination.

BACKGROUND AND AIMS: The increased use of salivary cortisol as a biomarker of stress and/or diurnal rhythms has facilitated research of Hypothalamic-pituitary-adrenocortical (HPA)function. Saliva collection remains problematic with preterm infants. The twofold purpose of this study is to 1) establish validity of the filter paper method for saliva collection and 2) apply the filter paper method for saliva collection to preterm infants. DESIGN AND MEASURES: Whole saliva was collected from six normal adult subjects to create a pool. Validation measures included comparison of levels obtained from whole saliva and filter paper, an evaluation of storage effects, assessing spiking recovery, and measurement of linearity of dilution. In the application study, saliva was collected every three hours, before feedings for three consecutive days from 26 hospitalized preterm infants. Diurnal variation in cortisol was examined using hierarchical linear modeling and individual calculation of diurnal pattern using an accepted technique. RESULTS: Validation studies revealed acceptable recovery of whole saliva from filters, no effect of room temperature storage of filters for up to six months, and acceptable linearity of dilution up to 4. Saliva from preterm infants was easily collected. Only 2% of the samples were lost due to inadequate wetting of the filters. An inverse association was found between postconceptional age and one-minute APGAR scores and infant cortisol levels. Variable daily cortisol patterns and no discernable rhythm were found for this sample; however, four infants appeared to show atypical diurnal pattern. CONCLUSIONS: The filter paper method is a valid method of saliva collection that is feasible to use with preterm infants.

Biomarkers↗

PubMed2005

Automated on-line SPE LC-MS/MS method to quantitate 6beta-hydroxycortisol and cortisol in human urine: use of the 6beta-hydroxycortisol to cortisol ratio as an indicator of CYP3A4 activity.

A sensitive method for quantitation of urinary 6beta-hydroxycortisol (6beta-HC) and cortisol using on-line SPE and LC-MS/MS was developed and validated. Human urine samples were injected directly onto an on-line solid phase extraction apparatus, Prospekt-2, followed by HPLC separation and electrospray triple quadrupole LC-MS/MS detection. The inter-day precision for the 6beta-HC:cortisol ratio was 7-9%. The lower limit of quantitation was 1 and 0.2 ng/mL for 6beta-HC and cortisol, respectively. Using the method we observed a diurnal variation on the 6beta-HC:cortisol ratio in healthy volunteers with the maximal ratio observed in the 2-10 pm urine collection period.

Autoanalysis↗

PubMed2006

Diurnal excretion of urinary cortisol, cortisone, and cortisol metabolites in chronic fatigue syndrome.

OBJECTIVE: The aim of this study was to obtain comprehensive information on basal hypothalamic-pituitary-adrenal (HPA) axis activity in chronic fatigue syndrome (CFS) patients who were not affected by medication or comorbid psychiatric disorder likely to influence the HPA axis. METHOD: Steroid analysis of urine collections from 0600 to 2100 h at 3-h intervals in CFS patients and in controls. RESULTS: Urinary free cortisol and cortisone concentrations showed a significant normal diurnal rhythm, but levels were lower across the cycle in CFS. In contrast, while urinary cortisol metabolites also showed a normal diurnal rhythm, levels were not significantly different between the CFS and controls at any time. Derived metabolite ratios were similar in both groups. CONCLUSION: This study provides further evidence for reduced basal HPA axis function in patients with CFS, based on lower free cortisol and cortisone levels, but this is not corroborated by cortisol metabolite data. The difference between these measures cannot be explained by an altered timing of the diurnal rhythm.

Adult↗

PubMed2005

Alterations in cortisol negative feedback inhibition as examined using the ACTH response to cortisol administration in PTSD.

OBJECTIVE: Studies using the dexamethasone suppression test (DST) have demonstrated an enhanced negative feedback inhibition at the pituitary in PTSD, but have not provided information about central feedback effects, since dexamethasone (DEX) does not penetrate the brain well. The authors therefore examined the change in ACTH and cortisol before and after cortisol administration, which acts at central feedback sites in addition to peripheral targets. METHOD: Blood was obtained from 31 male veterans (18 with PTSD) before, and 8, 40 and 95 min following injection of 17.5 mg cortisol and placebo. RESULTS: A greater decline in ACTH was observed after cortisol injection in PTSD. CONCLUSIONS: Central as well as peripheral negative feedback inhibition may be altered in PTSD.

Adrenocorticotropic Hormone↗

PubMed2001

Lower baseline plasma cortisol and prolactin together with increased body temperature and higher mCPP-induced cortisol responses in men with pedophilia.

There is some evidence that hormonal and serotonergic alterations may play a role in the pathophysiology of paraphilias. The aims of the present study were to examine: 1) baseline plasma cortisol, plasma prolactin, and body temperature; and 2) cortisol, prolactin, body temperature, as well as behavioral responses to meta-chlorophenylpiperazine (mCPP) and placebo in pedophiles and normal men. Pedophiles showed significantly lower baseline plasma cortisol and prolactin concentrations and a higher body temperature than normal volunteers. The mCPP-induced cortisol responses were significantly greater in pedophiles than in normal volunteers. In normal volunteers, mCPP-induced a hyperthermic response, whereas in pedophiles no such response was observed. mCPP induced different behavioral responses in pedophiles than in normal men. In pedophiles, but not in normal men, mCPP increased the sensations "feeling dizzy, " "restless," and "strange" and decreased the sensation "feeling hungry". The results suggest that there are several serotonergic disturbances in pedophiles. It is hypothesized that the results are compatible with a decreased activity of the serotonergic presynaptic neuron and a 5-HT2 postsynaptic receptor hyperresponsivity.

Adrenal Cortex Diseases↗

PubMed1980

Influence of oxygen tension and cortisol environment upon growth and cortisone conversion to cortisol by cultured human fetal lung fibroblasts.

Growth and conversion of cortisone to cortisol by human fetal lung fibroblasts in monolayer cell culture have been found to be sensitive to steady-state oxygen concentrations or to acute oxidant stresses. Oxygen-dependent differences are significantly modified by pre-incubation with cortisol. We speculate that cortisol may have an oxygen-protective role, and that the induction of increased conversion of cortisone to cortisol with an increase in oxygen tension, such at that observed at delivery, may be of significance in the prematurely born infant with the respiratory distress syndrome.

Cell Line↗

PubMed1982

Salivary cortisol determination: adaptation of a commercial serum cortisol kit.

The determination of cortisol levels in saliva offers a number of significant advantages as compared with plasma or serum measurements, and radioimmunoassay is the technique of choice because of the greater sensitivity required. To date, the assay of salivary cortisol has been limited to only a few centres employing 'in-house' reagents. We describe some simple modifications of a commercial kit, designed for the assay of cortisol in serum and urine, which allow direct and rapid determination of the steroid in saliva. These modifications enable any laboratory with access to a gamma counter to perform large numbers of salivary cortisol assays at relatively low cost.

Adult↗

PubMed2003

Midnight salivary cortisol versus urinary free and midnight serum cortisol as screening tests for Cushing's syndrome.

The diagnosis of Cushing's syndrome (CS) is often a challenge. Recently, the determination of late night salivary cortisol levels has been reported to be a sensitive and convenient screening test for CS. However, no studies have included a comparison with other screening tests in a setting more closely resembling clinical practice, i.e. few patients with CS to be distinguished from patients with pseudo-Cushing states (PC), including the large population of obese patients. The aim of this study was to compare the diagnostic performance of midnight salivary cortisol (MSC) measurement with that of midnight serum cortisol (MNC) and urinary free cortisol (UFC) in differentiating 41 patients with CS from 33 with PC, 199 with simple obesity, and 27 healthy normal weight volunteers. Three patients with CS had MSC levels lower than the cut-off point derived from receiver operator characteristic analysis (9.7 nmol/liter), yielding a sensitivity for this parameter of 92.7%. In the whole study population, no statistically significant differences in terms of sensitivity, specificity, diagnostic accuracy, and predictive values were observed among tests. In particular, the overall diagnostic accuracy for MSC (93%; 95% confidence interval, 90.1-95.9%) was similar to those of UFC (95.3%; 94.1-96.5%) and MNC (95.7%; 93.4-98%; both P = NS). The diagnostic performance of MSC was superimposable to that of MNC also within the area of overlap in UFC values (< or =569 nmol/24 h) between CS and PC. In conclusion, MSC measurement can be recommended as a first-line test for CS in both low risk (simple obesity) and high-risk (i.e. PC) patients. Given its convenience, this procedure can be added to tests traditionally used for this purpose, such as UFC and MNC.

Adolescent↗

PubMed2005

Preproorexin and orexin receptors are expressed in cortisol-secreting adrenocortical adenomas, and orexins stimulate in vitro cortisol secretion and growth of tumor cells.

Orexins A and B are hypothalamic peptides that originate from the proteolytic cleavage of preproorexin and act through two subtypes of receptors, named OX1-R and OX2-R. OX1-R almost exclusively binds orexin-A, whereas OX2-R is nonselective for both orexins. We previously found that orexin-A, via the OX1-R, stimulates cortisol secretion from dispersed human adrenocortical cells. In this study, we demonstrate that six of eight cortisol-secreting adenomas expressed preproorexin mRNA, and seven of 10 adenomas contained measurable amounts of orexin-A but not orexin-B. Normal adrenal cortexes neither expressed preproorexin nor contained orexins. All adenomas expressed OX1-R and OX2-R mRNAs, and real-time PCR showed that the expression of both receptors was up-regulated in adenomas, compared with normal adrenal cortex. Orexin-A concentration-dependently raised basal cortisol secretion from freshly dispersed normal and adenomatous cells, minimal and maximal effective concentrations being 10(-10) and 10(-8) m, and the peptide efficacy (percent increase elicited by 10(-8) m orexin-A) was significantly higher in adenomas than in the normal adrenal cortex. Orexin-B was ineffective, thereby indicating that orexin secretagogue action is mediated by the OX1-R. In contrast, both orexins (10(-8) m) raised the proliferative activity of cultured normal and adenomatous cells, suggesting that this effect is mediated by OX2-R or both receptor subtypes. Collectively, our findings allow us to conclude that the orexin system is overexpressed in cortisol-secreting adenomas and suggest that orexin-A may act as an autocrine-paracrine regulator of the secretory activity and growth of some of these adrenal tumors.

Adrenal Cortex Neoplasms↗

PubMed1979

Interrelationships of circulating maternal steroid concentrations in third trimester pregnancies. III. Effect of intravenous cortisol infusion on maternal concentrations of estriol, 16 alpha-hydroxyprogesterone, 17 alpha-hydroxyprogesterone, progesterone, 20 alpha-dihydroprogesterone, delta 5-pregnenolone, delta5-pregnenolone sulfate, dehydroepiandrosterone sulfate, and cortisol.

The effect of a large dose (1000 mg) of iv cortisol-hemisuccinate on circulating steroid concentrations in five women, 28--34 weeks, gestational age, is reported. Maternal concentrations of estriol, 16 alpha-hydroxyprogesterone, 17 alpha-hydroxyprogesterone, progesterone, 20 alpha-dihydroprogesterone, delta 5-pregnenolone, delta 5-pregnenolone sulfate, dehydroepiandrosterone sulfate, and cortisol were measured by RIA before and at 8 and 12 h after iv cortisol infusions at 0 and 8 h. Data were evaluated by repeated measure analysis of variance. Estriol and 17 alpha-hydroxyprogesterone suppressed initially (P less than 0.05) and suppressed further with retreatment and increased treatment time (P less than 0.05). Dehydroepiandrosterone sulfate and progesterone suppressed initially (P less than 0.05) but did not suppress further with retreatment and increased treatment time (P greater than 0.05). delta 5-Pregnenolone and delta5-pregnenolone sulfate increased initially (P less than 0.05) but did not increase further (P greater than 0.05). Concentrations of 16 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone were unchanged by cortisol infusion initially (P greater than 0.1) and with retreatment and increased treatment time (P greater than 0.1).

20-alpha-Dihydroprogesterone↗

PubMed1980

A comparative study of urinary 17-hydroxycorticosteroids, urinary free cortisol, and the integrated concentration of plasma cortisol.

The discriminatory power of three clinical tests for adrenal activity are compared by measuring the variability of the results obtained in 40 normal control subjects, 35 patients with mild essential hypertension, and 13 patients with Cushing syndrome. The variance of the 24-h integrated plasma concentration of cortisol was significantly (P < 0.0001) smaller than the variance of the 24-h urinary excretion of 17-hydroxycorticosteroids and free cortisol. While the 24-h urinary excretion of 17-hydroxycorticosteroids and free cortisol of the patients with Cushing syndrome overlapped with the corresponding values of the normal and hypertensive subjects, their integrated cortisol concentration did not exhibit any overlap.

17-Hydroxycorticosteroids↗

PubMed1979

Effects of obesity, total fasting and re-alimentation on L-thyroxine (T4), 3,5,3'-L-triiodothyronine (T3), 3,3',5'-L-triiodothyronine (rT3), thyroxine binding globulin (TBG), cortisol, thyrotrophin, cortisol binding globulin (CBG), transferrin, alpha 2-haptoglobin and complement C'3 in serum.

UNLABELLED: The effects of total fasting for 31 +/- 10 days followed by re-alimentation with an 800 calorie diet on thyroid function, i.e. T4,T3,rT3,RT3U (resin T3 uptake), and TSH, and on TBG levels in serum were studied sequentially in obese hospitalized patients (N=18). Additionally, cortisol, growth hormone, prolactin, parathyrin and free fatty acids were followed as hormonal and metabolic parameters, respectively. Further, CBG, transferrin, alpha 2-haptoglobin and complement C'3 were measured as representatives of other serum proteins. Results before fasting: T4, T3, TBG, cortisol, CBG, alpha 2-haptoglobin and complement C'3 of the obese patients were elevated when compared with healthy normal weight controls, whereas rT3, T4/TBG ratio, T3/TBG ratio, TSH, coritsol/cbg ratio, growth hormone, prolactin, parathyrin and transferrin of the obese group were normal. RT3U and fT4 index were decreased in the obese patients. Results during fasting: Significant decreases were observed during fasting for the following parameters -- T3, TBG, T3/TBG ratio, transferrin, alpha 2-haptoglobin complement C'3. rT3, T4/TBG ratio, RT3U, fT4 index and FFA increased. T4, tsh response to TRH stimulation, cortisol, CBG, cortisol/cbg ratio, parathyrin, growth hormone and prolactin did not change. Results during re-alimentation: T3, TBG, T3/TBG ratio, TSH response to TRH, transferrin, alpha 2-haptoglobin and complement C'3 increased. Conversely, fT3, RT3U, FFA, cortisol and cortisol/cbg ratio decreased whereas the other parameters did not change. CONCLUSIONS: 1) There is no evidence for primary hypothyroidism in obese patients during prolonged fasting and re-alimentation. 2) The rapid decrease of T3 and increase of RT3U after initiation of fasting are not fully explained by the observed slower decreases in TBG. 3) The alterations of T3, rT3 and RT3U resemble in their kinetics the changes in FFA levels. 4) Fasting reduced the levels of only certain serum proteins, interestingly TBG, transferrin, alpha 2-haptoglobin and complement C'3, all of which, except transferrin, are elevated in obesity. 5) The magnitude of the observed decreases does not suggest any clinically relevant deficiencies in serum proteins. 6) Re-alimentation reverses rapidly all observed changes.

Adult↗

PubMed1979

Ratio of amniotic fluid cortisol and maternal serum cortisol (AFC/MSC) as an index of fetal lung maturity.

Fifty-eight samples of amniotic fluid from pregnant women between the gestation period of 34-42 weeks were analyzed for total cortisol levels. Thirty-four simulatneous maternal serum total cortisol levels were also measured. Amniotic fluid cortisol (AFC), maternal serum cortisol (MSC) and the ratio of AFC/MSC were correlated with L/S ratio. AFC alone and AFC/MSC ratios correlate with L/S ratios (r=0.36, p less than 0.01, and r=0.46, p less than 0.01, respectively). MSC and L/S ratios had no correlation. AFC/MSC had less individual variation as compared to AFC alone. The AFC/MSC could be divided by an arbitrary line at 0.1 and values less than 0.1 signify immature fetal lungs. Values of 0.1 and greater signify mature fetal lungs.

Amniotic Fluid↗

PubMed1987

Measurement of free cortisol and the capacity and association constant of cortisol-binding proteins in plasma of foals and adult horses.

A direct method for measuring the capacity of the high-affinity binding protein, CBG, based on charcoal adsorption, was validated for use in the horse. Several unique aspects of cortisol binding in the horse were observed: (1) CBG content at birth was the lowest of any species studied, (2) CBG concentration increased with age whereas in other species it decreases, (3) the plasma of the new born foal has a binding protein, not reported for other species, which binds as much cortisol as does CBG. Its capacity and affinity are intermediate between albumin and CBG. It may be involved prenatally in increasing dam to fetus transfer of cortisol, and post-natally in buffering the effects of the huge stress-related peripartum release of cortisol.

Aging↗

PubMedDate not supplied

Radioimmunoassay of urinary cortisol: comparison of the procedures with and without previous cortisol extraction.

Although only less than 1% of the daily secreted cortisol is excreted unchanged into urine, the determination of urinary cortisol has proved to be a valuable parameter in evaluation of adrenocortical function. We compared the procedures of cortisol determination by radioimmunoassay after extraction and without extraction direct in crude urine. Direct determination needs less tracer and antibody and is less laborious. Intra- and interassay variance is 4.5%, 16.0% in the extraction method and 2.7%, 8.2% in the direct method, respectively. Comparison of both methods is acceptable (r = 0.92), recovery and dilution studies prove the direct method to be correct. Despite a lowered specificity, which gives higher results (factor 1.7) compared to the extraction method, the direct method is entirely sufficient for routine laboratory purposes. It can be achieved without additional equipment by laboratories, which determine total cortisol concentration in plasma.

Humans↗

PubMed1981

Cortisol resistant RPMI-1788 lymphocytes become sensitive to cortisol subsequent to a 24-h incubation period in medium containing purified human transcortin.

RPMI-1788 lymphocytes (a human cell line) are resistant to cortisol in vitro. Prior incubation for a minimum of 24 h in a medium which contains purified human transcortin at a concentration of 50 micrograms/ml renders these cells sensitive to the inhibitory action of cortisol as regards the synthesis of DNA. Only the transcortin-exposed cells contain a cortisol binding species whose sedimentation behavior in a sucrose gradient is identical to that of transcortin.

Cells, Cultured↗

PubMed1989

Cortisol and behavior: 1. Adaptation of a radioimmunoassay kit for reliable and inexpensive salivary cortisol determination.

We adapted a commercial serum cortisol radioimmunoassay (RIA) kit for use with saliva specimen. Using 50 microliters sample volume, the lower sensitivity was found to be 0.02 microgram/dl with intraassay variation coefficients between 5.4 and 8.9% at different concentrations. The 50% intercept was either 0.5 or 0.26 microgram/dl (50 or 100 microliters standard/sample volume). Fifty-four early morning samples from healthy adults showed absolute concentrations which are closely comparable to respective data from other laboratories. A comparison of 35 saliva samples which were each assayed with the adapted RIA as well as with three other commercial kits revealed high correlations between these assays (r = .94 to r = .97). Data on salivary cortisol responses to CRH stimulation and dexamethasone suppression in healthy subjects further the validity of the assay results. The most important contribution of this assay modification, however, is thought to be its impact on analysis costs: The protocol presented in this paper allows for reliable salivary cortisol measures with a reduction of costs for analytical material to 25% compared to serum determinations.

Corticotropin-Releasing Hormone↗

PubMed1991

Protein binding of cortisol by means of competitive adsorption: application to cortisol binding by serum of sixteen eutherian mammals.

1. Binding of 3H-cortisol by serum proteins by means of competitive adsorption was relatively high by serum of the gerbil, human, rabbit, sheep, tree shrew, hamster, rhesus monkey and horse. 2. A somewhat lower binding was observed by serum proteins of the baboon, cattle, dog, rat and cat. 3. Serum taken from either the mouse, guinea pig or pig gave very flat binding curves, specific binding not exceeding 5% of added 3H-cortisol. 4. It is concluded that the measurement of protein-binding of 3H-cortisol by means of competitive adsorption is a reliable method for serum of most eutherian species but is unsuited if serum of the mouse, guinea pig or pig is used.

Adrenal Cortex Hormones↗