Cerebrospinal fluid cortisol and clinical disease progression in MCI and dementia of Alzheimer's type.

Increased peripheral and central nervous system cortisol levels have been reported in Alzheimer's disease (AD) and may reflect dysfunction of cerebral components of the hypothalamic-pituitary-adrenal (HPA) axis. However, brain exposure to high cortisol concentrations may also accelerate disease progression and cognitive decline. The objectives of this study were to investigate whether HPA-axis dysregulation occurs at early clinical stages of AD and whether plasma and CSF cortisol levels are associated with clinical disease progression. Morning plasma and CSF cortisol concentrations were obtained from the subjects with AD dementia, mild cognitive impairment of AD type (MCI-AD), MCI of other type (MCI-O), and controls with normal cognition included in a multicenter study from the German Dementia Competence Network. A clinical and neuropsychological follow-up was performed in a subgroup of participants with MCI-AD, MCI-O, and AD dementia. CSF cortisol concentrations were increased in the subjects with AD dementia or MCI-AD compared with subjects with MCI-O or normal cognition. After controlling for possible confounders including CSF measures of amyloid beta1-42 and total tau, higher baseline CSF cortisol levels were associated with faster clinical worsening and cognitive decline in MCI-AD. The findings suggest that HPA-axis dysregulation occurs at the MCI stage of AD and may accelerate disease progression and cognitive decline.

SALO, a novel classical pathway complement inhibitor from saliva of the sand fly Lutzomyia longipalpis.

Blood-feeding insects inject potent salivary components including complement inhibitors into their host's skin to acquire a blood meal. Sand fly saliva was shown to inhibit the classical pathway of complement; however, the molecular identity of the inhibitor remains unknown. Here, we identified SALO as the classical pathway complement inhibitor. SALO, an 11 kDa protein, has no homology to proteins of any other organism apart from New World sand flies. rSALO anti-complement activity has the same chromatographic properties as the Lu. longipalpis salivary gland homogenate (SGH)counterparts and anti-rSALO antibodies blocked the classical pathway complement activity of rSALO and SGH. Both rSALO and SGH inhibited C4b deposition and cleavage of C4. rSALO, however, did not inhibit the protease activity of C1s nor the enzymatic activity of factor Xa, uPA, thrombin, kallikrein, trypsin and plasmin. Importantly, rSALO did not inhibit the alternative or the lectin pathway of complement. In conclusion our data shows that SALO is a specific classical pathway complement inhibitor present in the saliva of Lu. longipalpis. Importantly, due to its small size and specificity, SALO may offer a therapeutic alternative for complement classical pathway-mediated pathogenic effects in human diseases.

Long-term citalopram administration reduces responsiveness of HPA axis in patients with major depression: relationship with S-citalopram concentrations in plasma and cerebrospinal fluid (CSF) and clinical response.

RATIONALE: A dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is a well-documented neurobiological finding in major depression. Moreover, clinically effective therapy with antidepressant drugs may normalize the HPA axis activity. OBJECTIVE: The aim of this study was to test whether citalopram (R/S-CIT) affects the function of the HPA axis in patients with major depression (DSM IV). METHODS: Twenty depressed patients (11 women and 9 men) were challenged with a combined dexamethasone (DEX) suppression and corticotropin-releasing hormone (CRH) stimulation test (DEX/CRH test) following a placebo week and after 2, 4, and 16 weeks of 40 mg/day R/S-CIT treatment. RESULTS: The results show a time-dependent reduction of adrenocorticotrophic hormone (ACTH) and cortisol response during the DEX/CRH test both in treatment responders and nonresponders within 16 weeks. There was a significant relationship between post-DEX baseline cortisol levels (measured before administration of CRH) and severity of depression at pretreatment baseline. Multiple linear regression analyses were performed to identify the impact of psychopathology and hormonal stress responsiveness and R/S-CIT concentrations in plasma and cerebrospinal fluid (CSF). The magnitude of decrease in cortisol responsivity from pretreatment baseline to week 4 on drug [delta-area under the curve (AUC) cortisol] was a significant predictor (p<0.0001) of the degree of symptom improvement following 16 weeks on drug (i.e., decrease in HAM-D21 total score). The model demonstrated that the interaction of CSF S-CIT concentrations and clinical improvement was the most powerful predictor of AUC cortisol responsiveness. CONCLUSION: The present study shows that decreased AUC cortisol was highly associated with S-CIT concentrations in plasma and CSF. Therefore, our data suggest that the CSF or plasma S-CIT concentrations rather than the R/S-CIT dose should be considered as an indicator of the selective serotonergic reuptake inhibitors (SSRIs) effect on HPA axis responsiveness as measured by AUC cortisol response.

Nasal immunization of mice with human papillomavirus type 16 virus-like particles elicits neutralizing antibodies in mucosal secretions.

To specifically induce a mucosal antibody response to purified human papillomavirus type 16 (HPV16) virus-like particles (VLP), we immunized female BALB/c mice orally, intranasally, and/or parenterally and evaluated cholera toxin (CT) as a mucosal adjuvant. Anti-HPV16 VLP immunoglobulin G (IgG) and IgA titers in serum, saliva, and genital secretions were measured by enzyme-linked immunosorbent assay (ELISA). Systemic immunizations alone induced HPV16 VLP-specific IgG in serum and, to a lesser extent, in genital secretions but no secretory IgA. Oral immunization, even in the presence of CT, was inefficient. However, three nasal immunizations with 5 microgram of VLP given at weekly intervals to anesthetized mice induced high (>10(4)) and long-lasting (>15 weeks) titers of anti-HPV16 VLP antibodies in all samples, including IgA and IgG in saliva and genital secretions. CT enhanced the VLP-specific antibody response 10-fold in serum and to a lesser extent in saliva and genital secretions. Nasal immunization of conscious mice compared to anesthetized mice was inefficient and correlated with the absence of uptake of a marker into the lung. However, a 1-microgram VLP systemic priming followed by two 5-microgram VLP intranasal boosts in conscious mice induced both HPV16 VLP-specific IgG and IgA in secretions, although the titers were lower than in anesthetized mice given three intranasal immunizations. Antibodies in serum, saliva, and genital secretions of immunized mice were strongly neutralizing in vitro (50% neutralization with ELISA titers of 65 to 125). The mucosal and systemic/mucosal HPV16 VLP immunization protocols that induced significant titers of neutralizing IgG and secretory IgA in mucosal secretions in mice may be relevant to genital HPV VLP-based human vaccine trials.

Endocrine response and perceived stress test during an experimental challenge task in adult survivors of a childhood cancer.

BACKGROUND: Although long-term implications of cancer in childhood or adolescence with regard to medical conditions are well documented, the impact on mental health and on response to stress, which may be an indicator of psychological vulnerability, is not yet well understood. In this study, psychological and physiological responses to stress were examined.¦PROCEDURE: Fifty-three participants aged 18-39 years (n = 25 survivors of childhood or adolescence cancer, n = 28 controls) underwent an experimental stress test, the Trier Social Stress Test (TSST). Participants were asked to provide repeated evaluations of perceived stress on visual-analogical scales and blood samples were collected before and after the TSST to measure plasma cortisol.¦RESULTS: The psychological perception of stress was not different between the two groups. However, the cancer survivors group showed a higher global plasma cortisol level as well as higher amplitude in the response to the TSST. The global cortisol level in cancer survivors was increased when depression symptoms were present. The subjective perception of stress and the plasma cortisol levels were only marginally correlated in both groups.¦CONCLUSIONS: It is suggested that the exposure to a life-threatening experience in childhood/adolescence increases the endocrine response to stress, and that the presence of depressive symptoms is associated with an elevation of plasma cortisol levels. A better knowledge of these mechanisms is important given that the dysregulations of the stress responses may cause psychological vulnerability. Pediatr Blood Cancer 2012; 59: 138-143. © 2011 Wiley Periodicals, Inc.

The anabolic androgenic steroid fluoxymesterone inhibits 11β-hydroxysteroid dehydrogenase 2-dependent glucocorticoid inactivation.

Anabolic androgenic steroids (AAS) are testosterone derivatives used either clinically, in elite sports, or for body shaping with the goal to increase muscle size and strength. Clinically developed compounds and nonclinically tested designer steroids often marketed as food supplements are widely used. Despite the considerable evidence for various adverse effects of AAS use, the underlying molecular mechanisms are insufficiently understood. Here, we investigated whether some AAS, as a result of a lack of target selectivity, might inhibit 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2)-dependent inactivation of glucocorticoids. Using recombinant human 11β-HSD2, we observed inhibitory effects for several AAS. Whereas oxymetholone, oxymesterone, danazol, and testosterone showed medium inhibitory potential, fluoxymesterone was a potent inhibitor of human 11β-HSD2 (half-maximal inhibitory concentration [IC(50)] of 60-100nM in cell lysates; IC(50) of 160nM in intact SW-620, and 530nM in MCF-7 cells). Measurements with rat kidney microsomes and lysates of cells expressing recombinant mouse 11β-HSD2 revealed much weaker inhibition by the AAS tested, indicating that the adverse effects of AAS-dependent 11β-HSD2 inhibition cannot be investigated in rats and mice. Furthermore, we provide evidence that fluoxymesterone is metabolized to 11-oxofluoxymesterone by human 11β-HSD2. Structural modeling revealed similar binding modes for fluoxymesterone and cortisol, supporting a competitive mode of inhibition of 11β-HSD2-dependent cortisol oxidation by this AAS. No direct modulation of mineralocorticoid receptor (MR) function was observed. Thus, 11β-HSD2 inhibition by fluoxymesterone may cause cortisol-induced MR activation, thereby leading to electrolyte disturbances and contributing to the development of hypertension and cardiovascular disease.

Testosterone Restoration by Enclomiphene Citrate in Men with Secondary Hypogonadism: a pharmacodynamic and Pharmacokinetic study.

OBJECTIVES: To determine the pharmacodynamic (PD) profile of serum total testosterone levels (TT) and luteinizing hormone (LH) in men with secondary hypogonadism following initial and chronic daily oral doses of enclomiphene citrate in comparison to transdermal testosterone. To determine the effects of daily oral doses of enclomiphene citrate (Androxal®) in comparison to transdermal testosterone on other hormones and markers in men with secondary hypogonadism. PATIENTS AND METHODS: This was a randomized, single blind, two-center phase II study to evaluate three different doses of enclomiphene citrate (6.25mg, 12.5mg and 25 mg Androxal®), versus AndroGel®, a transdermal testosterone, on 24-hour LH and TT in otherwise normal healthy men with secondary hypogonadism. Forty-eight men were enrolled in the trial (ITT Population), but 4 men had T levels >350 ng/dL at baseline. Forty-four men completed the study per protocol (PP population). All subjects enrolled in this trial had serum TT in the low range (<350 ng/dL) and had low to normal LH (<12 IU/L) on at least two occasions. TT and LH levels were assessed each hour for 24 hours to examine the effects at each of three treatment doses of enclomiphene versus a standard dose (5 grams) of transdermal testosterone (AndroGel). In the initial profile TT and LH were determined in a naïve population following a single initial oral or transdermal treatment (Day 1). This was contrasted to that seen after six weeks of continuous daily oral or transdermal treatment (Day 42). The pharmacokinetics of enclomiphene was performed in a select subpopulation. Serum samples were obtained over the course of the study to determine levels of various hormones and lipids. RESULTS: After six weeks of continuous use, the mean ± SD concentration of TT at Day 42 C0hrTT, was 604 ± 160 ng/dL for men taking the highest of dose of enclomiphene citrate (enclomiphene, 25 mg daily) and 500 ± 278 ng in those men treated with transdermal testosterone. These values were higher than Day 1 values but not different from each other (p = 0.23, T-test). All three doses of enclomiphene increased C0hrTT, CavgTT, CmaxTT, CminTT and CrangeTT. Transdermal testosterone also raised TT, albeit with more variability, and with suppressed LH levels. The patterns of TT over 24 hour period following six weeks of dosing could be fit to a non-linear function with morning elevations, mid-day troughs, and rising night-time levels. Enclomiphene and transdermal testosterone increased levels of TT within two weeks, but they had opposite effects on FSH and LH Treatment with enclomiphene did not significantly affect levels of TSH, ACTH, cortisol, lipids, or bone markers. Both transdermal testosterone and enclomiphene citrate decreased IGF-1 levels (p<0.05) but suppression was greater in the enclomiphene citrate groups. CONCLUSIONS: Enclomiphene citrate increased serum LH and TT; however, there was not a temporal association between the peak drug levels and the Cmax levels LH or TT. Enclomiphene citrate consistently increased serum TT into the normal range and increased LH and FSH above the normal range. The effects on LH and TT persisted for at least one week after stopping treatment.

Techniques for analytical testing of unconventional samples.

Forensic scientists have long detected the presence of drugs and their metabolites in biological materials using body fluids such as urine, blood and/or other biological liquids or tissues. For doping analysis, only urine has so far been collected. In recent years, remarkable advances in sensitive analytical techniques have encouraged the analysis of drugs in unconventional biological samples such as hair, saliva and sweat. These samples are easily collected, although drug levels are often lower than the corresponding levels in urine or blood. This chapter reviews recent studies in the detection of doping agents in hair, saliva and sweat. Sampling, analytical procedures and interpretation of the results are discussed in comparison with those obtained from urine and blood samples.

Energy expenditure by doubly labeled water: validation in humans and proposed calculation.

To further validate the doubly labeled water method for measurement of CO2 production and energy expenditure in humans, we compared it with near-continuous respiratory gas exchange in nine healthy young adult males. Subjects were housed in a respiratory chamber for 4 days. Each received 2H2(18)O at either a low (n = 6) or a moderate (n = 3) isotope dose. Low and moderate doses produced initial 2H enrichments of 5 and 10 X 10(-3) atom percent excess, respectively, and initial 18O enrichments of 2 and 2.5 X 10(-2) atom percent excess, respectively. Total body water was calculated from isotope dilution in saliva collected at 4 and 5 h after the dose. CO2 production was calculated by the two-point method using the isotopic enrichments of urines collected just before each subject entered and left the chamber. Isotope enrichments relative to predose samples were measured by isotope ratio mass spectrometry. At low isotope dose, doubly labeled water overestimated average daily energy expenditure by 8 +/- 9% (SD) (range -7 to 22%). At moderate dose the difference was reduced to +4 +/- 5% (range 0-9%). The isotope elimination curves for 2H and 18O from serial urines collected from one of the subjects showed expected diurnal variations but were otherwise quite smooth. The overestimate may be due to approximations in the corrections for isotope fractionation and isotope dilution. An alternative approach to the corrections is presented that reduces the overestimate to 1%.

Une IgA à coefficient de sédimentation 11 S dans les sécrétions externes de l'espèce bovine

The sedimentation coefficient of a secretory IgA found in bovine colostrum and saliva is compared with that of IgG and IgM from the same colostrum. The IgA fraction gives a value of 10.8 S, whereas the major part of the IgG has a value of 7.1 S and the IgM 19.2 S. The sedimentation coefficient of the free secretory piece has also been determined: its value is 4.95 S.

Abrupt decrease in serum testosterone levels after an oral glucose load in men: implications for screening for hypogonadism.

OBJECTIVE: This study examines the physiological impact of a glucose load on serum testosterone (T) levels in men with varying glucose tolerance (GT). DESIGN: Cross-sectional study. PATIENTS AND METHODS: 74 men (19-74 years, mean 51·4 ± 1·4 years) underwent a standard 75-g oral glucose tolerance test with blood sampling at 0, 30, 60, 90 and 120 min. Fasting serum glucose, insulin, total T (and calculated free T), LH, SHBG, leptin and cortisol were measured. RESULTS: 57% of the men had normal GT, 30% had impaired GT and 13% had newly diagnosed type 2 diabetes. Glucose ingestion was associated with a 25% decrease in mean T levels (delta = -4·2 ± 0·3 nm, P < 0·0001). T levels remained suppressed at 120 min compared with baseline (13·7 ± 0·6 vs 16·5 ± 0·7 nm, P < 0·0001) and did not differ across GT or BMI. Of the 66 men with normal T levels at baseline, 10 (15%) had levels that decreased to the hypogonadal range (<9·7 nm) at one or more time points. SHBG, LH and cortisol levels were unchanged. Leptin levels decreased from baseline at all time points (P < 0·0001). CONCLUSIONS: Glucose ingestion induces a significant reduction in total and free T levels in men, which is similar across the spectrum of glucose tolerance. This decrease in T appears to be because of a direct testicular defect, but the absence of compensatory changes in LH suggests an additional central component. Men found to have low nonfasting T levels should be re-evaluated in the fasting state.

Abus sexuel, psychopathologie et réponses psycho-endocriniennes au stress

Résumé : Des événements traumatiques précoces peuvent favoriser le développement ultérieur de psychopathologies telles que les troubles anxieux ou dépressifs. Dans quelle mesure ces événements influencent-ils la réaction d'un sujet à un stress aigu ? Objectif : comparer la prévalence de troubles psychiatriques et déterminer la différence de réaction au stress à l'âge adulte de femmes ayant ou non subi un traumatisme de type abus sexuel dans leur enfance. Participants : 46 femmes âgées de 22 à 48 ans recrutées entre juin 2004 et juillet 2006 réparties en 2 groupes (groupe contrôle de 16 sujets, groupe traumatisé de 30 sujets). L'étude se déroule dans l'Unité de recherche du SUPEA, rue du Bugnon 25A, 1005 Lausanne. Mesures : hormone adrenocorticotropiqué (ACTI-I), cortisol plasmatique et salivaire, fréquence cardiaque au cours du TSST (test psychosocial de stress standardisé), réponses aux questionnaires standardisés VAS (visual analog scale) et MDBF (Mehrdimensionale Befindlichkeitsfragebogen), MINI (mini international neuropsychiatric interview), ETI (early trauma inventory). Les différences de cóncentration d'ACTH et de cortisol, du rythme cardiaque, et des réponses aux questionnaires VAS et MDBF entre des groupes contrôle et abus ont été analysés (ANOVA, ANalysis Of VAriance). Lorsque les résultats montraient une grande hétérogénéité, nous .avons également appliqué les tests de Mann-Whitney et de Kruskal-Wallis: Résultats principaux : les personnes abusées dans leur enfance souffrent à l'âge adulte plus fréquemment de troubles psychiatriques selon les critères du MINI DSM-IV. Ces personnes réagissent fortement au stress, mais seules leurs réponses subjectives montrent des différences significatives par rapport à un groupe de contrôle.

Blunting the response to endotoxin in healthy subjects: effects of various doses of intravenous fish oil.

To test the dose response effect of infused fish oil (FO) rich in n-3 PUFAs on the inflammatory response to endotoxin (LPS) and on membrane incorporation of fatty acids in healthy subjects. Prospective, sequential investigation comparing three different FO doses. Three groups of male subjects aged 26.8 +/- 3.2 years (BMI 22.5 +/- 2.1). One of three FO doses (Omegaven10%) as a slow infusion before LPS: 0.5 g/kg 1 day before LPS, 0.2 g/kg 1 day before, or 0.2 g/kg 2 h before. Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-alpha, stress hormones) were collected. After LPS temperature, ACTH and TNF-alpha concentrations increased in the three groups: the responses were significantly blunted (p < 0.0001) compared with the control group of the Pluess et al. trial. Cortisol was unchanged. Lowest plasma ACTH, TNF-alpha and temperature AUC values were observed after a single 0.2 g/kg dose of FO. EPA incorporation into platelet membranes was dose-dependent. Having previously shown that the response to LPS was reproducible, this study shows that three FO doses blunted it to various degrees. The 0.2 g/kg perfusion immediately before LPS was the most efficient in blunting the responses, suggesting LPS capture in addition to the systemic and membrane effects.

Oxytocin response to an experimental psychosocial challenge in adults exposed to traumatic experiences during childhood or adolescence.

Long-term implications of the exposure to traumatizing experiences during childhood or adolescence, such as sexual abuse, or cancer, have been documented, namely the subjects' response to an acute stress in adulthood. Several indicators of the stress response have been considered (e.g. cortisol, heart rate). Oxytocin (OT) response to an acute stress of individuals exposed to trauma has not been documented. Eighty subjects (n=26 women who had experienced episodes of child abuse, n=25 men and women healthy survivors of cancer in childhood or adolescence, and 29 controls) have been submitted to a laboratory session involving an experimental stress challenge, the Trier social stress test. Overall, there was a clear OT response to the psychosocial challenge. Subjects having experienced a childhood/adolescence life-threatening illness had higher mean levels of OT than both abused and control subjects. There was a moderate negative relationship between OT and salivary cortisol. It is suggested that an acute stress stimulates OT secretion, and that the exposure to enduring life-threatening experiences in childhood/adolescence has long-lasting consequences regarding the stress system and connected functions, namely the activation of OT secretion. Better knowledge of such long-term implications is important so that to prevent dysregulations of the stress responses, which have been shown to be associated to the individual's mental health.