Legacy environmental polychlorinated biphenyl contamination attenuates the acute stress response in a cartilaginous fish, the Round Stingray.

In a population of Round Stingrays (Urobatis halleri) sampled from mainland California (polychlorinated biphenyl [PCB] exposed site, n = 46), relative to a nearby offshore island (reference site, n = 34), we tested the hypothesis that stingrays from the PCB-exposed site would have a compromised stress response. Adult male and pregnant female (pregnancy = matrotrophic histotrophy), stingrays were captured via hook and line at both locations over a breeding season and plasma was sampled either immediately (Baseline, males = 10, females = 31), or after ∼5 min of struggle on the line followed by a 15 min confinement stressor (Stressed, males = 16, females = 23). Biomarkers of the primary stress response (1α-OH-corticosterone) and the secondary response (energy mobilization; glucose, glycogen, and lactate in liver and muscle) were assessed. Females from both sites demonstrated the expected primary stress response of 1α-OH-corticosterone elevation, but the contaminant-exposed males did not. PCB-exposed stingrays, regardless of sex, failed to produce a plasma glucose increase in response to the applied stress, even though the stressor increased liver glucose as expected. This suggests a dysfunction in glucose transport due to PCB exposure. The Round Stingray accumulates lower PCB loads than other, predatory elasmobranchs, and by extension, the stress axis effects could be more severely impacted in those species as well. Lay summary Legacy polychlorinated biphenyl (PCB) contamination continues to adversely affect marine life. We show that PCB-exposure interferes with the ability of pregnant female and adult male stingrays to mobilize the energy necessary to respond appropriately to an acute stress like capture. Other cartilaginous fish species, such as sharks, accumulate considerably more PCB as a result of their predatory diet, and are likely to be more adversely impacted.

Steroid concentrations in maternal serum and uterine histotroph in round stingrays (Urobatis halleri).

Despite a wide range of elasmobranch (sharks, skates and rays) matrotrophic strategies, and thus potentially diverse pathways for maternal-fetal hormone exchange, little attention has been given to uterine steroids during development. Round Stingrays (Urobatis halleri) with matrotrophic histotrophy were captured during every month of their annual reproductive season from post-ovulation to near parturition, and paired samples of plasma and histotroph were analyzed for a suite of steroid hormones using LC-ESI/MRM. Hormone concentrations within and between maternal and uterine compartments were compared using two markers of embryo development. Histotroph had consistently higher detection rates and concentrations of hormones than maternal plasma, especially during early pregnancy when embryos are yolk sac-dependent for nutrition. Peaks in histotroph testosterone concentrations preceded maternal plasma, suggesting that hormones were locally produced within the uterine compartment. Embryonic sexual differentiation based on the presence of visible claspers (male copulatory organs) coincided with peaks in histotroph progesterone, testosterone, 17-hydroxyprogesterone and estradiol, suggesting that, like mammalian pregnancy, elasmobranch embryonic steroids also contribute to their own developmental environment.

Cortisol Stress Response Variability in Early Adolescence: Attachment, Affect and Sex.

Attachment, affect, and sex shape responsivity to psychosocial stress. Concurrent social contexts influence cortisol secretion, a stress hormone and biological marker of hypothalamic-pituitary-adrenal axis activity. Patterns of attachment, emotion status, and sex were hypothesized to relate to bifurcated, that is, accentuated and attenuated, cortisol reactivity. The theoretical framework for this study posits that multiple individual differences mediate a cortisol stress response. The effects of two psychosocial stress interventions, a modified Trier Social Stress Test for Teens and the Frustration Social Stressor for Adolescents were developed and investigated with early adolescents. Both of these protocols induced a significant stress reaction and evoked predicted bifurcation in cortisol responses; an increase or decrease from baseline to reactivity. In Study I, 120 predominantly middle-class, Euro-Canadian early adolescents with a mean age of 13.43 years were studied. The girls' attenuated cortisol reactivity to the public performance stressor related significantly to their self-reported lower maternal-attachment and higher trait-anger. In Study II, a community sample of 146 predominantly Euro-Canadian middle-class youth, with an average age of 14.5 years participated. Their self-reports of higher trait-anger and trait-anxiety, and lower parental attachment by both sexes related differentially to accentuated and attenuated cortisol reactivity to the frustration stressor. Thus, attachment, affect, sex, and the stressor contextual factors were associated with the adrenal-cortical responses of these adolescents through complex interactions. Further studies of individual differences in physiological responses to stress are called for in order to clarify the identities of concurrent protective and risk factors in the psychosocial stress and physiological stress responses of early adolescents.

Human intermittent hypoxia-induced respiratory plasticity is not caused by inflammation.

Ventilatory instability, reflected by enhanced acute hypoxic (AHVR) and hypercapnic (AHCVR) ventilatory responses is a fundamental component of obstructive sleep apnoea (OSA) pathogenesis. Intermittent hypoxia-induced inflammation is postulated to promote AHVR enhancement in OSA, although the role of inflammation in intermittent hypoxia-induced respiratory changes in humans has not been examined. Thus, this study assessed the role of inflammation in intermittent hypoxia-induced respiratory plasticity in healthy humans.In a double-blind, placebo-controlled, randomised crossover study design, 12 males were exposed to 6 h of intermittent hypoxia on three occasions. Prior to intermittent hypoxia exposures, participants ingested (for 4  days) either placebo or the nonsteroidal anti-inflammatory drugs indomethacin (nonselective cyclooxygenase (COX) inhibitor) and celecoxib (selective COX-2 inhibitor). Pre- and post-intermittent hypoxia resting ventilation, AHVR, AHCVR and serum concentration of the pro-inflammatory cytokine tumour necrosis factor (TNF)-α were assessed.Pre-intermittent hypoxia resting ventilation, AHVR, AHCVR and TNF-α concentrations were similar across all three conditions (p≥0.093). Intermittent hypoxia increased resting ventilation and the AHVR similarly across all conditions (p=0.827), while the AHCVR was increased (p=0.003) and TNF-α was decreased (p=0.006) with only selective COX-2 inhibition.These findings indicate that inflammation does not contribute to human intermittent hypoxia-induced respiratory plasticity. Moreover, selective COX-2 inhibition augmented the AHCVR following intermittent hypoxia exposure, suggesting that selective COX-2 inhibition could exacerbate OSA severity by increasing ventilatory instability.

Acute BVDV-2 infection in beef calves delays humoral responses to a non-infectious antigen challenge.

Immunosuppressive effects of an intranasal challenge with non-cytopathic bovine viral diarrhea virus (BVDV) 2a (strain 1373) were assessed through acquired and innate immune system responses to ovalbumin (OVA). Concurrent BVDV infection was hypothesized to delay and reduce the humoral response to ovalbumin (administered on days 3 and 15 post-inoculation). Infected animals followed the expected clinical course. BVDV titers, and anti-BVDV antibodies confirmed the course of infection and were not affected by the administration of OVA. Both the T-helper (CD4(+)) and B-cell (CD20(+)) compartments were significantly (P < 0.05) reduced in infected animals, while the gamma-delta T-cell population (Workshop cluster 1+, WC1(+)) decreased slightly in numbers. Infection with BVDV delayed the increase in OVA IgG by approximately 3 d from day 12 through day 21 post-inoculation. Between days 25 and 37 post-inoculation following BVDV infection the IgM concentration in the BVDV- group decreased while the OVA IgM titer still was rising in the BVDV+ animals. Thus, active BVDV infection delays IgM and IgG responses to a novel, non-infectious antigen.

Une infection aiguë par le BVDV-2 chez les veaux retarde les réponses humorales face à un test à l'aide d'un antigène non infectieux. Les effets immunosuppressifs d'une inoculation défin intranasale à l'aide du virus non cytopathogène de la diarrhée virale bovine (VBVD) 2a (souche 1373) ont été évalués par les réactions acquises et innées du système immunitaire à l'ovalbumine (OVA). On a émis l'hypothèse que l'infection concomitante par le VBVD retardait et réduisait la réaction humorale à l'ovalbumine (administrée aux jours 3 et 15 après l'inoculation). Les animaux infectés ont suivi le cheminement clinique prévu. Les titres de BVDV et les anticorps anti-BVDV ont confirmé le déroulement de l'infection et ils n'ont pas été affectés par l'administration d'OVA. Les compartiments des lymphocytes T auxiliaires (CD4+) et des cellules B (CD20+) étaient significativement réduits (P < 0,05) chez les animaux infectés, tandis que la numération de la population de cellules T gamma-delta (WC1+) a diminué légèrement. L'infection par le VBVD a retardé l'augmentation de l'OVA IgG d'environ 3 jours, à compter du jour 12 jusqu'au jour 21 après l'inoculation. Entre les jours 25 et 37 après l'inoculation suivant l'infection par le BVDV, la concentration d'IgM dans le groupe VBVD a diminué tandis que le titre d'OVA IgM augmentait toujours chez les animaux positifs pour le VBVD. Par conséquent, l'infection active par le VBVD retarde les réactions IgM et IgG face à un antigène non infectieux nouveau.(Traduit par Isabelle Vallières).

Limited efficacy of Fever Tag(®) temperature sensing ear tags in calves with naturally occurring bovine respiratory disease or induced bovine viral diarrhea virus infection.

Temperature sensing ear tags were tested in 1) auction-derived calves with 50% incidence of bovine respiratory disease, and 2) specific pathogen-free calves infected with bovine virus diarrhea virus. There were no false positives, but tag placement, probe displacement, and a high threshold for activation all contributed to failure to reliably detect sick calves.

Efficacité limitée des étiquettes d'oreille Fever TagMDpour mesurer la température chez les veaux atteints de maladies respiratoires d'origine naturelle ou d'une infection induite par le virus de la diarrhée virale des bovins. Les étiquettes d'oreille pour mesurer la température ont été testées chez 1) des veaux provenant d'encans ayant 50 % d'incidence de maladies respiratoires et 2) des veaux exempts d'agents pathogènes spécifiques infectés par le virus de la diarrhée virale bovine. Il n'y avait aucun faux positif, mais le placement des étiquettes, le déplacement de la sonde et un seuil d'activation élevé ont tous contribué à l'échec de la détection fiable des veaux malades.(Traduit par Isabelle Vallières).

Transport versus on-farm slaughter of bison: physiological stress, animal welfare, and avoidable trim losses.

Ranched bison are typically less acclimated to handling than are domesticated livestock, suggesting that they might be more vulnerable to handling and transportation stressors. Grain-finished bison were slaughtered on-farm (n = 11), or held for 48 h, transported to a research abattoir, held in lairage for 18 h, and then slaughtered (n = 11). An additional group (n = 10) was sampled at a conventional fixed location abattoir. Measures included serum cortisol and corticosterone concentrations during on-farm handling and exsanguination, serum glucose, creatinine phosphokinase (CPK), aspartate aminotransferase (AST), and trim losses. Transport was associated with an increase in trim loss. On-farm, glucose was elevated, CPK was positively associated with handling order over 12 h, and corticosterone concentration, although lower than cortisol concentration, showed a greater response to prolonged disturbance. With appropriate on-farm handling facilities, the use of on-farm slaughter and mobile abattoir could avoid muscle damage and trim losses, and mitigate injuries sustained during handling and transport of bison.

Transport ou abattage des bisons à la ferme : stress physiologique, bien-être animal et pertes de viande évitables. Les bisons élevés dans un ranch sont habituellement moins accoutumés à la manipulation que le bétail domestiqué, ce qui suggère qu'ils sont plus vulnérables aux facteurs de stress liés à la manipulation et au transport. Des bisons engraissés au grain ont été abattus à la ferme (n = 11), ou détenus pendant 48 h, transportés à un abattoir de recherche, mis dans des installations d'attente pendant 18 h, puis abattus (n = 11). Un groupe additionnel (n = 10) a été échantillonné à un abattoir fixe conventionnel. Les mesures incluaient les concentrations de cortisol sérique et de corticostérone durant la manipulation et l'exsanguination à la ferme, le glucose sérique, la créatinine phosphokinase (CPK), l'aspartate aminotransférase (AST) et les pertes de viande. Le transport était associé à une hausse de la perte de viande. À la ferme, le glucose était élevé, la CPK était positivement associée à l'ordre de manipulation pendant 12 heures et la concentration de corticostérone, quoique inférieure à la concentration de cortisol, a montré une réponse plus élevée lors d'une perturbation prolongée. Avec des installations de manipulation à la ferme appropriées, l'utilisation de l'abattage à la ferme et d'un abattoir mobile pourrait éviter les dommages musculaires et les pertes de viande et atténuer les blessures subies durant la manipulation et le transport des bisons.(Traduit par Isabelle Vallières).

Saliva Cortisol as a Biomarker of Injury in Youth Sport-Related Concussion.

Increasing rates of sport-related concussion (SRC) in youth impose a significant burden on public health systems and the lives of young athletes. Accurate prediction for those likely to develop persistent post-concussion symptomology (PPCS) using a fluid biomarker, reflecting both acute injury and recovery processes, would provide the opportunity for early intervention. Cortisol, a stress hormone released through the hypothalamic-pituitary-adrenal (HPA) axis following injury, may provide a missing physiological link to clinical recovery. This cohort study investigated the change in saliva cortisol following SRC and the association between cortisol and symptom burden in pediatric ice hockey players. Further, the association between cortisol levels and medical clearance to return to play was explored. In total, cortisol samples from 233 players were included; 165 athletes (23.6% female) provided pre-injury saliva and 68 athletes (19.1% female) provided post-SRC saliva samples for cortisol analysis. Quantile (median) regressions were used to compare cortisol between pre-injury and post-SRC groups, and the association between total symptoms (/22) and symptom severity scores (/132) reported on the Sport Concussion Assessment Tool (SCAT)3/SCAT5 and post-SRC cortisol (adjusting for age, sex, history of concussion, and time from injury to sample collection). Results demonstrated significantly lower saliva cortisol in post-SRC athletes compared with the pre-injury group (ß = -0.62, 95% confidence interval [CI; -1.08, -0.16], p = 0.009). Post-SRC cortisol was not significantly associated with the SCAT3/SCAT5 symptom totals or symptom severity scores; however, females were found to report more symptoms (ß = 6.95, 95% CI [0.35, 13.55], p = 0.040) and greater symptom severity (ß = 23.87, 95% CI [9.58, 38.15], p = 0.002) compared with males. Exploratory time-to-event analysis revealed a point estimate suggesting a potential association between low cortisol levels and days to medical clearance to return to play. Although preliminary, these findings suggest that the HPA axis may be dysregulated post-SRC. Further, our exploratory analysis and case presentation of post-injury outliers highlight the need to further research cortisol as a prognostic biomarker to inform individualized sex-specific care after SRC.

Non-breeding feather concentrations of testosterone, corticosterone and cortisol are associated with subsequent survival in wild house sparrows.

Potential mechanistic mediators of Darwinian fitness, such as stress hormones or sex hormones, have been the focus of many studies. An inverse relationship between fitness and stress or sex hormone concentrations has been widely assumed, although empirical evidence is scarce. Feathers gradually accumulate hormones during their growth and provide a novel way to measure hormone concentrations integrated over time. Using liquid chromatography-tandem mass spectrometry, we measured testosterone, corticosterone and cortisol in the feathers of house sparrows (Passer domesticus) in a wild population which is the subject of a long-term study. Although corticosterone is considered the dominant avian glucocorticoid, we unambiguously identified cortisol in feathers. In addition, we found that feathers grown during the post-nuptial moult in autumn contained testosterone, corticosterone and cortisol levels that were significantly higher in birds that subsequently died over the following winter than in birds that survived. Thus, feather steroids are candidate prospective biomarkers to predict the future survival of individuals in the wild.

Cortisol and corticosterone independence in cortisol-dominant wildlife.

Species have traditionally been defined as cortisol-dominant or corticosterone-dominant, depending on the glucocorticoid that is reported. To assess the degree of covariance versus independence between cortisol and corticosterone, 245 serum samples belonging to 219 individuals from 18 cortisol-dominant, non-domesticated species (6 mammalian orders) were compared by mass spectrometry. In these samples, which were elevated above baseline, concentration ranges were overlapping for cortisol and corticosterone although cortisol was dominant in every sample except one of 17 bighorn sheep with a corticosterone-biased cortisol-to-corticosterone ratio of 0.17. As expected, cortisol and corticosterone were strongly associated among species (r(2)=0.8; species with high absolute cortisol tend to have high absolute corticosterone concentrations), with wide variation in the species-average cortisol-to-corticosterone ratio (range 7.5-49) and an even wider ratio range across individuals (0.2-341). However, only 9 out of 13 species with >7 individuals showed a positive association between cortisol and corticosterone among individuals, and repeated measures of the cortisol-to-corticosterone ratio within individuals were weakly associated (CV range 3-136%). We conclude that corticosterone, although at lower concentrations, has the potential to signal independently of cortisol, and should be included in integrated endocrine models of stress responses.

Migratory carryover effects and endocrinological correlates of reproductive decisions and reproductive success in female albatrosses.

Physiological mechanisms mediating carryover effects, wherein events or activities occurring in one season, habitat, or life-history stage affect important processes in subsequent life-history stages, are largely unknown. The mechanism most commonly invoked to explain carryover effects from migration centres on the acquisition and utilization of resources (e.g. body mass, or individual 'condition'). However, other mechanisms are plausible, e.g. trade-offs reflecting conflict or incompatibility between physiological regulatory systems required for different activities or life-history stages (migration vs. reproduction). Here we show that in female black-browed albatrosses (Thalassarche melanophris) the decision to reproduce or to defer reproduction, made prior to their arrival at breeding colonies after long-distance migration, is associated with condition-related (body mass, hematocrit, hemoglobin concentrations) and hormonal (progesterone, testosterone, estrogen-dependent yolk precursors) traits. In contrast, reproductive success showed little association with condition but showed significant associations with the steroidogenic processes underlying follicle development. Specifically, success was determined by reproductive readiness via differences in steroid hormones and hormone-dependent traits. Successful albatrosses were characterized by high progesterone and high estradiol-dependent yolk precursor levels, whereas failed albatrosses had high testosterone and low yolk precursor levels. Results are discussed with reference to migratory carryover effects and how these can differentially affect the physiologies influencing reproductive decisions and reproductive success.

The stress-response-dampening effects of placebo.

This experiment used both biological and self-report measures to examine how alcohol modifies stress responses, and to test whether the interaction between these two factors alters risk-taking in healthy young adults. Participants were divided into stress or no-stress conditions and then further divided into one of three beverage groups. The alcohol group consumed a binge-drinking level of alcohol; the placebo group consumed soda, but believed they were consuming alcohol; the sober group was aware that they were not consuming alcohol. Following beverage consumption, the stress group was subjected to the Trier Social Stress Test (TSST) while the no-stress group completed crossword puzzles; all participants subsequently completed a computerized risk-taking task. Exposure to the TSST significantly increased salivary levels of the hormone cortisol and the enzyme alpha-amylase, as well as subjective self-ratings of anxiety and tension. In the stress condition, both placebo and intoxicated groups reported less tension and anxiety, and exhibited a smaller increase in cortisol, following the TSST than did the sober group. Thus, the expectation of receiving alcohol altered subjective and physiological responses to the stressor. Neither alcohol nor stress increased risk taking, however the sober group demonstrated lower risk-taking on the computer task on the second session. These findings clearly demonstrate that the expectation of alcohol (placebo) alters subsequent physiological responses to stress.

Sublethal, sex-specific, osmotic, and metabolic impairments in embryonic and adult round stingrays from a location exposed to environmental contamination in southern California, USA.

Organic contaminants are known to affect a suite of physiological processes across vertebrate clades. However, despite their ancient lineage and important roles in maintaining healthy ecosystems, elasmobranchs (sharks, skates, and rays) are understudied with regard to sublethal effects of contaminant exposure on metabolic processes. Perturbations resulting from contaminant exposure can divert energy away from maintaining physiological homeostasis, particularly during energetically challenging life stages, such as pregnancy and embryonic development. Using the round stingray (Urobatis halleri) as a model elasmobranch species, we captured adult males and pregnant females (matrotrophic histotrophy) and their embryos from two populations differing in their environmental exposure to organic contaminants (primarily polychlorinated biphenyls (PCBs)). Pregnant females from the PCB-exposed population experienced significant decreases from early- to late-pregnancy in tissue mass and quality not seen in reference females. PCB-exposed pregnant females also failed to maintain plasma urea concentrations as pregnancy progressed, which was accompanied by a loss in muscle protein content. Despite the energetic demands of late-term pregnancy, females had significantly greater liver lipid content than reproductively inactive adult males. PCB-exposed adult males also had high metabolic capacity (i.e., enzyme activity) for most substrate groupings of all sex-site groups, suggesting that males may be even more negatively impacted by contaminant exposure than pregnant females. Evidence that in utero exposure to PCBs via maternal offloading impairs embryo outcomes is accumulating. Embryos from the PCB-contaminated site had lower tissue quality measures and indications that sex-based differences were manifesting in utero as males had higher metabolic capacities than females. This study indicates that accumulated PCB contaminants are not physiologically inert in the stingray.

Cortisol reactivity to stress predicts behavioral responsivity to reward moderation by sex, depression, and anhedonia.

Depression is associated with blunted reactivity to acute stress, as well as blunted responsivity to rewards. However, the extent to which responses to stress are associated with responses to reward in individuals meeting criteria for a depressive disorder is unknown. The goal of this study was to examine the relation of responses to stress and reward, and to determine if this relation is moderated by depression diagnosis, anhedonia, and sex. Participants included 114 adults (68 depressed, 46 non-depressed; 75% women) recruited from the community. Stress reactivity was operationalized as the total salivary cortisol output to the Trier Social Stress Test (TSST; Kirschbaum et al., 1993). Response bias to monetary reward was assessed following the TSST recovery period with a probabilistic reward task (PRT; Pizzagalli et al., 2005). In men only, total cortisol output during the TSST was more strongly positively associated with response bias to reward across the three blocks of the PRT. In addition, among depressed participants with high levels of anhedonia, higher cortisol output during the TSST was significantly associated with higher overall response bias to reward. We suggest that in men, the stress and reward systems may both respond quickly, and resolve rapidly, in the face of acute stress. Further, in depression, our findings suggest that anhedonia may represent a specific phenotype in which the stress and reward systems are particularly tuned together.

The significance of biological variation in the diagnosis of testosterone deficiency, and consideration of the relevance of total, free and bioavailable testosterone determinations.

PURPOSE: The diagnosis of testosterone deficiency syndrome is based on clinical manifestations and documentation of low testosterone. Which biochemical tests to use and the importance of morning sampling are still controversial. Biological variation (including interindividual and intraindividual biological variation) must be considered when interpreting individual results as it determines the usefulness of reference intervals and the change (reference change value) necessary for a significant difference between results. MATERIALS AND METHODS: A total of 87 healthy men (50 to 70+ years old) provided blood in the morning of the first day, and 4 weeks later in the morning and afternoon. Samples were frozen (-70C) and analyzed in the same run for serum testosterone, sex hormone-binding globulin and albumin, and bioavailable testosterone and free testosterone were calculated. RESULTS: Serum testosterone was lower in the afternoon by 1.5 nmol/l (43 ng/dl, p <0.05), with larger changes observed with higher morning values. However, this diurnal effect was dwarfed by the normal biological variation observed for repeat morning samples (serum testosterone +/- 4 nmol/l [115 ng/dl]). Between day intra-individual biological variation for morning serum testosterone was 18.7% while within day intra-individual biological variation was 12.9%. A change of 52% (reference change value) is necessary between serial morning results to confirm a significant difference. The biological variation parameters of calculated bioavailable testosterone and calculated free testosterone confer no advantage over total testosterone. CONCLUSIONS: Marked individuality of serum testosterone is evident even in healthy men. Because intraindividual biological variation is less than interindividual biological variation, reference intervals are marginally useful. The homeostatic set point of a patient could decrease by half and still be within the reference interval. Prospective establishment of an individual's baseline over repeated measurements or symptoms regardless of serum testosterone concentration should be used to guide clinical decisions.

Substrates and Clearance Products of Fetal Adrenal Glucocorticoid Synthesis in Full-Term Human Umbilical Circulation.

In full-term elective caesarian sections, fetal flow of adrenal substrate steroids to products differs by sex, with males (M) in molar equilibrium whereas females (F) add net molarity and synthesize more cortisol. Using the same sampling design, paired, full-term, arterial, and venous umbilical cord samples and intrapartum chart records were obtained at the time of vaginal delivery (N = 167, 85 male) or emergency C-section (N = 38, 22 male). Eight steroids were quantified by liquid chromatography coupled to tandem mass spectrometry (adrenal glucocorticoids [cortisol, corticosterone], sequential cortisol precursor steroids [17-hydroxyprogesterone, 11-deoxycortisol], cortisol and corticosterone metabolites [cortisone and 11-dehydrocorticosterone], and gonadal steroids [androstenedione, testosterone]). Fetal sex was not significant in any analytic models. Going through both phase 1 and phase 2 labor increased fetal adrenal steroidogenesis and decreased male testosterone relative to emergency C-sections that do not reach stage 2 of labor (ie, head compressions) and elective C-sections with no labor. Sum adrenal steroid molarity arriving in venous serum was almost double the equivalent metric for deliveries without labor. No effects of operative vaginal delivery were noted. Maternal regional anesthetic suppressed venous concentrations, and fetal synthesis replaced that steroid. Approximate molar equivalence between substrate pool depletion and net glucocorticoid synthesis was seen. Paired venous and arterial umbilical cord serum has the potential to identify sex differences that underlie antenatal programming of hypothalamic-pituitary-adrenal axis function in later life. However, stage 2 labor before the collection of serum, and regional anesthetic for the mother, mask those sex differences.

Of 11 candidate steroids, corticosterone concentration standardized for mass is the most reliable steroid biomarker of nutritional stress across different feather types.

Measuring corticosterone in feathers has become an informative tool in avian ecology, enabling researchers to investigate carry-over effects and responses to environmental variability. Few studies have, however, explored whether corticosterone is the only hormone expressed in feathers and is the most indicative of environmental stress. Essential questions remain as to how to compare hormone concentrations across different types of feathers and whether preening adds steroids, applied after feather growth.We used liquid chromatography coupled to tandem mass spectrometry to quantify a suite of 11 steroid hormones in back, breast, tail, and primary feathers naturally grown at overlapping time intervals by rhinoceros auklet Cerorhinca monocerata captive-reared fledglings and wild-caught juveniles. The captive-reared birds were raised on either a restricted or control diet. Measured steroids included intermediates in the adrenal steroidogenesis pathway to glucocorticoids and the sex steroids pathway to androgens and estrogens.Corticosterone was detected in the majority of feathers of each type. We also detected cortisone in back feathers, androstenedione in breast feathers, and testosterone in primary feathers. Captive fledglings raised on a restricted diet had higher concentrations of corticosterone in all four feather types than captive fledglings raised on a control diet. Corticosterone concentrations were reliably repeatable across feather types when standardized for feather mass, but not for feather length. Of the seven hormones looked for in uropygial gland secretions, only corticosterone was detected in one out of 23 samples.We conclude that corticosterone is the best feather-steroid biomarker for detection of developmental nutritional stress, as it was the only hormone to manifest a signal of nutritional stress, and that exposure to stress can be compared among different feather types when corticosterone concentrations are standardized by feather mass.

Sex differences in substrates and clearance products of cortisol and corticosterone synthesis in full-term human umbilical circulation without labor: Substrate depletion matches synthesis in males, but not females.

BACKGROUND: Antenatal impacts on the hypothalamus- pituitary-adrenal axis affect health throughout later life and the impacts on developing males and females often differ. The female fetus at full-term (sampled as scheduled Caesarian section without antecedent labor) both receives more cortisol in umbilical venous blood and adds more cortisol to umbilical arterial circulation than the male. The current study was designed to expand our knowledge of sex-specific, fetal, adrenal steroid synthesis and clearance pathways. METHODS: Paired, full-term, arterial and venous umbilical cord samples were taken at the time of scheduled Caesarian delivery (N = 53, 33 male). Adrenal glucocorticoids (cortisol, corticosterone), cortisol precursor steroids (17-hydroxyprogesterone, 11-deoxycortisol), and cortisol and corticosterone metabolites (cortisone and 11-dehydrocorticosterone), as well as gonadal steroids (testosterone and androstenedione), were quantified by liquid chromatography coupled to tandem mass spectrometry. RESULTS: Both sexes preferentially added corticosterone. Males added more testosterone than females. The female fetus had higher umbilical cord (arterial and venous) concentrations of cortisol, as well as higher total steroid molarity summed across the six adrenal steroids, than males. Depletion of substrate pools of 17-hydroxyprogesterone, 11-deoxycortisol, and cortisone could account for only 20% of net female cortisol synthesis. In contrast, increased fetal synthesis of cortisol was balanced by equivalent molar depletion of substrate pools when the fetus was male. CONCLUSIONS: Preferential fetal corticosterone synthesis in both sexes, and higher concentrations of cortisol in females were confirmed. Differences in adrenal steroidogenesis pathway function in full-term males and females might underlie antenatal programming of hypothalamic-pituitary-adrenal axis function in later life.

Quantitative meta-analysis of maternal prenatal salivary cortisol and newborn birthweight does not identify effect of fetal sex.

BACKGROUND: Heightened concentration of maternal cortisol is a frequently proposed mechanism linking adverse maternal environments with poor birth outcomes, including birth weight. It is commonly hypothesized that prenatal exposures have sexually dimorphic effects on fetal development, however few studies have assessed the effects of fetal sex on the relationship between maternal cortisol and birth outcomes. METHODS: In a previous systematic review and meta-analysis we obtained data from authors of included studies to calculate trimester-specific correlations between maternal prenatal salivary cortisol and newborn birth weight. Given that this data was well-poised to address the unknown effects of fetal sex on the relationship between maternal cortisol and birth outcomes, we contacted authors a second time with request to unblind sex into the correlations. An updated database search was conducted to identify potentially relevant articles published within 2018 and two additional articles were included. RESULTS AND DISCUSSION: Eleven studies with a total of 2236 maternal-fetal dyads demonstrated negative correlations for both males, -0.15 (95% CI -0.24 to -0.06, I2 = 98.5%, p < 0.001) and females -0.21 (95% CI -0.25 to -0.17, I2 = 93.3%, p < 0.001). Sex difference were not statistically significant, p = 0.62. Despite greater exposure to cortisol and lower birth weight among females, the association did not differ by sex.