Cerebrospinal fluid (CSF) hypocretin-1/orexin-A quantification via radioimmunoassay (RIA) is used for diagnosing narcolepsy type 1(NT1), but its limitations require alternative methods. Using liquid chromatography-mass spectrometry (LC-MS), this study aimed to 1) fully characterize CSF orexin-A fragments detected by the gold standard RIA method, and 2) assess diagnostic relevance of measuring the most prevalent fragment, a 16-mer, in patients with NT1, narcolepsy type 2 (NT2), idiopathic hypersomnia (IH), and nonspecified hypersomnolence (NSH). CSF samples were analyzed using RIA and LC-MS in patients with hypersomnolence disorders evaluated at the French Narcolepsy National Reference Center. Fractionation techniques isolated orexin-A and its fragments, which were identified via targeted MS. Statistical analysis compared LC-MS performance against RIA. CSF samples from 115 patients (54.8% females, mean age 30.4 ± 15.8years) including 52 with NT1, 6 NT2, 13 IH, and 44 NSH were analyzed by RIA and LC-MS. A 16-mer orexin-A fragment was identified and quantified by LC-MS, with lower levels in NT1. This fragment correlated strongly with RIA-measured orexin-A (r = 0.83, p < .0001) and demonstrated high sensitivity (98.1%) and specificity (85.7%) for diagnosis of NT1. Receiver operating characteristics analyses confirmed the high performance with an area under the curve of 0.975 and an optimal diagnostic cutoff of 10.67pg/mL for LC-MS. The 16-mer orexin-A peptide represents a promising biomarker that could in the future help in the diagnosis of central hypersomnolence disorders. The transition from RIA to LC-MS methods for the quantification of 16-mer orexin-A represents a critical advance toward improving diagnostic accuracy and understanding orexinergic dysfunction in sleep disorders.

After decades of dramatic reductions in their populations, Italian wolves have begun recolonizing parts of their historic range. This growth in populations can lead to potential conflicts with human activities, which remain the main cause of wolf mortality. With the aim of examining animal welfare and their health status, a hormonal dosage on hair was conducted on 20 wolf carcasses originating from the Tuscany and Emilia‐Romagna regions. The concentrations of cortisol, testosterone, dehydroepiandrosterone (DHEA), progesterone, and oestradiol (E2) were measured using radioimmunoassay (RIA). Our results, listed as mean ± SD, were cortisol 1.81 ± 1.17, testosterone 2.74 ± 1.6, DHEA 62.92 ± 24.99, P4 53.22 ± 32.8 and E2 0.46 ± 0.23 pg/mg. The study employed a novel approach to analyse hormone levels in this species, but its opportunistic nature resulted in uneven data distribution across sex and age groups. Consequently, comparisons of hormone levels by these categories did not yield relevant differences. Further studies with larger sample sizes are necessary to analyse hormone trends throughout the year and explore differences based on factors such as sex, age, and causes of death.

ContextIn clinical practice, plasma arginine vasopressin (AVP) concentrations have been measured with a radioimmunoassay (RIA). However, RIAs have limitations, such as long turnaround time, use of radioisotopes, and restricted antibody availability. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers a promising alternative, eliminating the need for radioisotopes and antibodies while providing faster results.ObjectiveThis study aimed to assess the usefulness of LC-MS/MS for measuring plasma AVP concentrations in diagnosing AVP deficiency (AVP-D).MethodsWe included 16 patients with AVP-D and 28 controls. All participants underwent a hypertonic saline infusion test (HST), during which plasma AVP concentrations were measured using RIA and LC-MS/MS. Regression coefficients (gradients) for serum sodium vs plasma AVP concentrations were evaluated at 90 and 120 minutes, and receiver-operating characteristic analyses were performed based on these regression coefficients.ResultsThe area under the receiver-operating characteristic curve at 90 minutes was 0.97 (95% CI, 0.83-1.00) and 0.93 (95% CI, 0.80-0.98) for LC-MS/MS and RIA, respectively. A regression gradient cutoff with optimal values distinguished AVP-D from controls with a sensitivity of 100% in LC-MS/MS and RIA, whereas the specificity was 96% and 81% with LC-MS/MS and RIA, respectively. Sensitivity or specificity did not differ in 120 minutes between the 2 methods.ConclusionLC-MS/MS demonstrated superior diagnostic accuracy for AVP-D at 90 minutes of HST, indicating that the HST time can be shortened from 120 to 90 minutes by measuring AVP with LC-MS/MS.Clinical trial registrationThe study was registered with the University Hospital Medical Information Network (UMIN) registry (UMIN000043023).

Prostate-specific antigen (PSA) is a protein produced by the prostate gland and is a critical biomarker for the early detection and monitoring of prostate cancer. Current methods in the detection of PSA include enzyme-linked immunosorbent assay (ELISA), chemiluminescent immunoassays (CLIA), and radioimmunoassay (RIA). They are expensive and time-consuming processes, even though they are considered the gold standard. On the other hand, biosensing technology is an emerging alternative method for the detection of PSA. Electrochemical immunosensor systems are widely used for detecting a variety of antigens with high selectivity and specificity. In this study, to prepare an immunosensor for PSA detection, a thiophene appended cobalt(II) phthalocyanine (CoPc), its polymer (Poly-Pc), and CuCoFe2O4@MoS2-NH2 were synthesized. Then, anti-PSA antibodies were immobilized on the CuCoFe2O4@MoS2-NH2-based Poly-Pc composite using glutaraldehyde as a cross-linker, and the immunosensor was prepared. Differential pulse voltammetry (DPV) employed to monitor the measurements showed that the proposed immunosensor system exhibited excellent analytical performance, with a wide linear detection range (0.01-1000 ng/mL) and a low detection limit of 6.3 pg/mL. The proposed immunosensor system offered high selectivity, reproducibility, and stability, even in complex biological samples such as synthetic serum, which was compared to a commercially available ELISA kit. The obtained results showed that the immunosensor has the potential to be used in clinical diagnosis as a rapid and reliable tool for PSA detection.

Angiotensin-converting enzyme 2 (ACE2)has been identified as abiomarker and a promising therapeutic target in several diseases.The noninvasive visualization of in vivo ACE2 mapping is urgent fordisease guidance and treatment assessment. A radioimmuno assay methodadapting to the RBD peptide library was proposed here to screen ahigh ACE2-specific peptide sequence as the targeting molecule. Derivedfrom the constructed RBD peptide libraries of the dominant Omicronvariants (BA.1, BA.2, and BA.5), the superior peptide was high-throughputscreened through the binding rate to the HEK293-hACE2 cell and verifiedby the molecular docking with ACE2. Further, biodistribution studieswere conducted through 125I-based SPECT imaging. The DOTA-modifiedderivant was labeled with Ga-68 to enable ACE2-targeted PET imaging.The peptide 505HQPYRVVVLSFELLH519 (named asOmi-X) showed a superior ACE2 binding via molecular docking and cellularassays. 125I-labeled Omi-X SPECT imaging demonstrated thehigh ACE2-specificity and binding retention in K18-hACE2 mice, togetherwith an ideal performance in labeling stability and flexibility. TheACE2-targeted PET imaging tracers68Ga-DOTA-Omi-Xrealized the ACE2 mapping and further applicability in RAAS-relateddiseasescardiac hypertrophy, intuitively reflecting the ACE2expression and regulating role. This natural evolution-guided approachnot only enabled a noninvasive visualization of ACE2 but also establisheda paradigm for developing targeted therapies by leveraging viral-hostadaptation mechanisms. Our work bridged natural evolution and targetmolecule screening and offered imaging tools for RAAS pathophysiology,investigation, and precision diagnostics.

Background Adrenal venous sampling (AVS) is essential for diagnosing unilateral aldosterone oversecretion in primary aldosteronism (PA). Traditionally, AVS relies on radioimmunoassay (RIA) to measure plasma aldosterone concentration (PAC), although RIA has limited specificity and considerable variability. This study evaluated the role of liquid chromatography-tandem mass spectrometry (LC-MS/MS) in AVS and its impact on clinical outcomes.Methods Among 230 patients with PA (May 2020 to April 2023) who underwent AVS, successful sampling was achieved in 182 patients (79.1%) under unstimulated conditions and 206 patients (89.6%) under stimulated conditions. PAC levels from peripheral and adrenal veins measured by LC-MS/MS were compared with RIA results. Patient outcomes were categorized according to the Primary Aldosteronism Surgical Outcomes criteria.Results LC-MS/MS showed significant correlations with PAC levels measured by RIA in AVS (r=0.40 [unstimulated] and r=0.56 [stimulated]; both P<0.001). However, lateralization concordance between RIA and LC-MS/MS was moderate, at only 57.7% (unstimulated) and 64.6% (stimulated). LC-MS/MS identified more unilateral disease than RIA under both unstimulated (61.5% vs. 37.4%, P<0.001) and stimulated conditions (36.4% vs. 9.7%, P<0.001). Patients achieving complete clinical success after adrenalectomy were more accurately identified by LC-MS/MS than RIA under stimulated (55.6% vs. 22.2%, P=0.035), but not in unstimulated conditions.Conclusion LC-MS/MS outperformed RIA in identifying unilateral disease, resulting in higher rates of complete clinical success in adrenalectomy patients when surgical decisions were based on LC-MS/MS lateralization results.

Orexin-A/hypocretin-1 level is determined in the cerebrospinal fluid samples as a part of clinical narcolepsy diagnostics utilizing a specific commercial radioimmunoassay (RIA); this assay is also widely used in research of many other conditions. The specificity of RIAs is in general variable, and little has been firmly disclosed about the specificity of this RIA assay. Thus, the validity of many research results obtained using the kit is unclear. At least metabolites of orexin-A have been proposed as potential interfering substances. Since this issue has not been systematically assessed, we decided to investigate it using synthetic variants of orexin-A and -B (intact peptides and peptide fragments as well as reduced orexin-A). Our synthetic orexin-A bound correspondingly to the orexin-A standard included in the kit while orexin-B did not bind even at 10000-fold higher concentrations. Reduction of the disulfide bridges in orexin-A (giving orexin-A-SS) decreased its binding 25-fold. C-terminal truncation of orexin-A-SS was well tolerated - some of the fragments actually bound better than orexin-A-SS - while N-terminal truncation was not allowed. The results demonstrate that the RIA kit is fairly selective for intact orexin-A among the peptides tested. However, this does not as such prove that it measures intact orexin-A in the physiological samples, and further studies including identification of physiological orexin-A metabolites are thus required. We also suggest that the redox milieu of cerebrospinal fluid - that has been suggested to vary in different diseases - may have an impact on what is measured with the kit.

A new role for glucagon: from secondary hormone to key player.

Abstract This study evaluated the effects of transportation timing on cortisol concentrations and pregnancy rates in goats undergoing laparoscopic artificial insemination (LAI). In year 1, 20 does (1.6 years old) were randomly assigned to Early Haul (transported 24 hours before LAI) or Late Haul (transported on the day of LAI). Does were transported for three hours, synchronized, and blood samples were collected at multiple time points relative to transport and breeding: -24 hours before transportation (-24 IT), at initial transportation (0 IT), three hours post-transport (3 IT), at breeding (0 B), and at 24, 48, and 72 hours post-transport. Serum cortisol concentrations were determined via radioimmunoassay (RIA) and analyzed using the MIXED procedure in SAS, with pregnancy rates analyzed via GLIMMIX procedures. Cortisol levels varied over time (P &amp;lt; 0.0001) but changes relative to timing of transportation did not differ between haul groups (P = 0.11). A treatment × time interaction was observed (P &amp;lt; 0.0001) with the Early Haul sample 0 B having a lower serum cortisol concentration (3.89 ng/mL ± 2.34) when compared to late haul 0 B (8.18 ng/mL ± 2.34). Pregnancy rates did not differ (P = 0.24) elevated in Early Haul (50%) compared to Late Haul (22%). In year 2, 18 yearling does were treated similarly and bred by the same sire as does in year 1. Sampling was conducted at -24 IT, 0 IT, 3 IT, and 0 B, with additional samples at loading for the return trip (3 h after breeding; 0 RT), three hours post-return transport (3 RT), and at 12, 24, and 72 hours post-initial transport. Cortisol levels again varied significantly over time (P &amp;lt; 0.0001), with a treatment by time interaction (P &amp;lt; 0.0001). The lowest cortisol concentration was observed in Early Haul 0 RT (3.25 ng/mL ±3.08) compared to late haul (5.93 ng/mL ± 3.08). Overall, Late Haul had greater serum cortisol levels than Early Haul (P = 0.0006). Year 2 pregnancy rates did not differ (P = 0.61) between Early (33%) and Late (22%) haul groups. Overall, transporting goats 24 hours before LAI resulted in lower cortisol concentrations, which may positively impact pregnancy rates.

Abstract Introduction Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations, with its pathogenesis linked to hypocretin/orexin deficiency, a key regulator of the sleep-wake cycle. This study compares the diagnostic performance of radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) in measuring cerebrospinal fluid (CSF) hypocretin levels in narcolepsy patients. Methods Twenty-five narcolepsy patients were diagnosed based on clinical symptoms and electrophysiological tests. CSF hypocretin levels were measured using RIA and ELISA, with a hypocretin level of &amp;lt; 110 pg/ml considered diagnostic for narcolepsy type I according to established criteria. Results RIA showed a significantly lower average hypocretin level (9.77±5.65 pg/ml) compared to ELISA (134.56±57.21 pg/ml). Among the 25 patients, 17 were diagnosed with narcolepsy, all of whom had RIA measurements below 110 pg/ml, achieving 100% sensitivity. In contrast, only 4 patients had hypocretin levels &amp;lt; 110 pg/ml using ELISA, resulting in a sensitivity of 23.53%. RIA demonstrated higher sensitivity for detecting low hypocretin concentrations, while ELISA was more accurate for higher concentrations but less sensitive at lower levels. Conclusion RIA demonstrated superior sensitivity and accuracy in detecting low cerebrospinal fluid (CSF) hypocretin levels, which makes it highly valuable for the early diagnosis and ongoing monitoring of the disease. Despite these advantages, its complexity and associated costs pose significant limitations to its widespread clinical applicability. In contrast, ELISA, while less sensitive at very low concentrations, offers greater accessibility and is more suitable for large-scale screening programs. Clinicians are advised to select the most appropriate method based on their specific diagnostic requirements. This study not only contributes to the refinement of diagnostic strategies for narcolepsy but also offers valuable insights that could be applied to broader neurological disorders. Support (if any)

Abstract Objectives The evaluation of male hypogonadism encompasses clinical parameters and biochemical measures of total testosterone (T), sex hormone-binding globulin (SHBG), and free T. Laboratory standardization is however lacking, leading to methodological inconsistencies between laboratories and varying reference ranges. We investigated inter-laboratory methodologic differences in total T, SHBG, and free T in clinical laboratories throughout Europe. Methods An internet-based, open-invitation survey was distributed from December 2022 to December 2023 by the Royal Belgian Society for Laboratory Medicine (RBSLM), the Dutch Association for Clinical Chemistry and Laboratory Medicine (NVKC), the European Academy for Andrology (EAA), the European Federation for Laboratory Medicine (EFLM), the European Society for Sexual Medicine (ESSM), and Andronet. Belgian clinical laboratories were also directly contacted by e-mail. Included in this survey on total T, SHBG, and free T were sampling, methodology, reference ranges, and reporting of results. Results A total of 124 records were analyzed representing clinical laboratories from 27 European countries. These laboratories were private-sector (20.2%), research-focused (1.6%), or associated with a general (38.7%) or tertiary/university hospital (39.5%). Methodologies used for total T included enzyme-linked immunoassay (IA) (72.7%), radioimmunoassay (RIA) (1.7%), mass spectrometry (MS) (8.3%), or a combination (17.3%). While only 43.0% of respondents recommended sampling time to clinicians, even less recommended fasting (25.4%). When reporting total T (IA vs. MS), laboratories used non-stratified (20.0% vs. 16.7%) or age-stratified (79.0% vs. 70.8%) reference ranges. For SHBG, all laboratories used IA and reported using non-stratified (34.0%) or age-stratified (65.0%) reference ranges, for which a majority provided the assay manufacturer as the source (83.1%). Free T was performed using calculation (79.3%) or measurement (10.3%) methods or a combination (10.3%). Calculation of free T was predominantly done by the Vermeulen formula (84.2%). Measurement of free T was performed (n = 10) by direct IA or RIA (60.0% and 20.0%) or MS after equilibrium dialysis or liquid–liquid extraction (20.0%). Conclusions We observed heterogeneity in measurement and reporting of total T, SHBG, and free T between clinical laboratories in Europe, highlighting the necessity of harmonization and standardization. Conflicts of Interest N/A.

Evaluation of plasma arginine vasopressin during hypertonic saline loading: A comparison of radioimmunoassay and liquid chromatography-tandem mass spectrometry.

Fish gonadal melatonin production is still unexplored and could contribute to a better understanding of its role in reproduction control, especially for species with reproductive impairments. This study aimed to comprehend if Senegalese sole testes are an extra-pineal production site of melatonin and if it has seasonal and daily variations. Wild and F1 broodstocks were sampled in the breeding season (BS) and out of the reproductive season (OS), at mid-light (ML) and mid-dark (MD) daytimes. Blood plasma melatonin concentration was determined by radioimmunoassay (RIA). The expression of genes involved in melatonin biosynthesis (tph1a, tph2, hiomt1, aanat1a, aanat1b, and aanat2) and melatonin receptors (mel1, mel1c, and mel2) was evaluated in the brain, eye, and testis by quantitative real-time PCR (qPCR). Plasma melatonin concentration in wild sole displayed day/night differences in both seasons (average ML: 36 ± 22 pg/mL, MD: 108 ± 63 pg/mL), whereas differences in the F1 broodstock were only found OS (ML: 100 ± 54 pg/mL, MD: 187 ± 88 pg/mL). Gene expression of mel1 and mel2 receptors, and tph1a, aanat1a, aanat2, and hiomt1 enzymes was detected and quantified in the fish testes. Moreover, daily and seasonal fluctuations in the expression of those genes were found in all tissues and broodstock groups. However, the F1 group showed distinct gene expression patterns compared to the wild type, suggesting a disruption in the circadian system. This study revealed that Senegalese sole testes are a melatonin production site and, at the same time, suggested a dysregulation in the hypothalamus-pituitary-gonad (HPG) axis of F1 males.

It is a standard approach to evaluate analytical processes in a laboratory routinely. Especially if it involves the study of key hormones like testosterone, progesterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH), which are required for the diagnosis of various health conditions. The aim of this study was to evaluate the sensitivity, cross-reactivity, precision, parallelism, and recovery of radioimmunoassay (RIA) of these hormone parameters to establish their reliability and suitability for clinical applications. The performance parameters were evaluated by using RIA to assay several control and clinical samples as well as their dilutions and multiple combinations of mixtures. The assays showed high precision, sensitivity, selectivity, and accuracy. The result reaffirms the reliability and robustness of RIA as an analytical tool for quantification of FSH, LH, testosterone, and progesterone. Future studies on other hormone RIAs and across other laboratories are required to further validate the result. Bangladesh J. Nuclear Med. 27(2): 229-233, 2024

Musth is a normal physiological phenomenon exhibited predominately by adult healthy dominant bull elephants.The condition is characterized by aggressive behavior due to increased reproductive activity in adult male elephants of both Asian and African species.Physiological, anatomical, and behavioral manifestations are commonly observed during annual musth due to the remarkable elevation of testosterone in the body.The present study investigates serum testosterone and cortisol concentrations in adult bull Asian elephants during pre-musth and non-musth conditions using Radioimmunoassay (RIA).Serum testosterone (67.68 9.98 ng/mL) and cortisol (419.4256.64ng/mL) concentrations in elephants in pre-musth were significantly higher (p>0.01)than in normal elephants.The Pearson correlation between testosterone and cortisol in normal elephants was statistically insignificant (r=-0.067,p=0.791), while in elephants in the pre-musth period, it was insignificant but positively correlated (r=0.302,p=0.561).The regression model predicts that in the pre-musth condition, testosterone increases by approximately 0.05 (ng/mL) as cortisol increases by 1 ng/mL on average, whereas in normal adults, testosterone decreases by 0.001 (ng/mL).However, 9.11% of the variability in testosterone can be explained by the linear association between testosterone and cortisol in elephants during the pre-musth period, in contrast the same was only 0.45% in normal adults.This is the first interim investigation reported on the hormonal profile of elephants in relation to the pre-musth period from the state of Assam, India.

Background: Obesity has a detrimental impact on most organ systems, including the reproductive system and leads to impairments in ovarian, follicular, and oocyte development, fertilization, and embryo development and implantation. The term "ovarian reserve" refers to the quantity and quality of a woman's current reservoir of oocytes and is closely associated with reproductive potential. It naturally declines with age from puberty to menopause. Methods: 50 obese women and 50 non-obese women in the reproductive age group were selected in the study. Measured body mass index (BMI), anti-mullerian hormone (AMH), follicle-stimulating hormone (FSH), antral follicular count (AFC) and ovarian volume (OV) in both obese and non-obese women. The comparison of age and BMI, FSH and AMH, AFC and ovarian volume was done by using t test and P value less than 0.001 was considered statistically significant. Serum FSH and AMH levels were analyzed using radioimmunoassay (RIA) technique while AFC and ovarian volume were determined through transvaginal ultrasonography respectively. Results: This study showed statistically significant lower values of Anti-Müllerian Hormone (AMH), Antral Follicle Count (AFC), and ovarian volume, alongside higher values of Follicle-Stimulating Hormone (FSH), compared to the non-obese women of the same age group. Slightly elevated levels of serum FSH and lower levels of serum AMH, reduced Antral Follicle Count (AFC), and smaller ovarian volume, in obese women compared to non-obese women were shown. Conclusion: This study concludes that obese women exhibit lower AMH levels, AFC and Ovarian volume, along with higher FSH levels, compared to non-obese women of the same age group. These findings suggest that obesity has a detrimental effect on ovarian reserve markers and may impact reproductive health, emphasizing the importance of weight management for preserving fertility.

Background: Sexual function decline in male heroin addicts during methadone maintenance treatment (MMT) is a problem, and the link between methadone doses and sex hormone levels in this group is unclear. This cross - sectional study explored HPG axis hormone levels and their association with methadone doses in Chinese MMT - treated heroin addicts. Methods: All participants provided blood samples. Sexual hormones, including testosterone (T), progesterone (P), prolactin (PRL), follicle - stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2), were measured using radioimmunoassay (RIA). The relationship between different methadone doses (“&lt;=30 mg/d”, “31 - 60mg/d”, and “&gt;=61mg/d”) and sex hormones was analyzed via general linear modeling (GLM). Results: The study included 103 male heroin addicts receiving methadone maintenance treatment (MMT) and 79 healthy male controls. No significant differences were found in the levels of all sex hormones among different methadone doses (all P&gt;0.05). After adjusting for age and the duration of MMT, no significant associations were detected between different methadone doses and the six hormone levels. Conclusion: No dose - response relationship was observed for the six hormone levels. The significance of considering the independence of methadone dose effects on the HPG axis hormone levels of heroin addicts in MMT should be carefully evaluated.

House dust mite (HDM) allergens are one of the most important causes of allergenic diseases in the indoor environment. The World Health Organization (WHO) has defined risk thresholds for Group I HDM allergens as a concentration of 2 and 10 μg/mL in dust for producing asthma risk and polar asthma attacks, respectively. Continuing exposure to high concentrations of HDM allergens greatly increases the risk of developing allergic diseases. Therefore, it's necessary to determine the exposure levels of HDM allergens to estimate the risk. So, various approaches have been developed to directly or indirectly detect HDM allergens in the environment. This paper overviews the developmental progress of HDM allergen detection and introduces the principle of HDM allergen detection methods, including semi-quantitative radioallergosorbent test (RAST), ACAREX test, dot immunobinding assay (DIBA), radioimmunoassay (RIA) which combines the high sensitivity and accuracy, enzyme-linked immunosorbent assay (ELISA) with high accuracy, fluorescent multiple arrays which can simultaneously detect multiple HDM allergens, polymerase chain reaction (PCR), and liquid chromatograph-mass spectrometer (LC-MS) with high sensitivity and accuracy. The paper provides an overall understanding of the development of HDM allergen detection methods and guidance for choosing an appropriate method to detect HDM allergens.

Background: Misalignment between internal circadian timing and environmental time cues, such as light, has been associated with poor cardiometabolic health. We examined whether artificial light at night (ALAN) was associated with higher asleep blood pressure (BP) and lower melatonin levels in a sample of Black adults. Methods: Normotensive Black adults were recruited from a parent study examining circadian contribution to BP. Participants wore the Philips Respironics Actiwatch 2 for seven consecutive days and during the first 24 hours, they also completed 24-hour ambulatory BP monitoring (ABPM) using the SpaceLabs 90227 device. Saliva was collected hourly during a 30-hour constant routine protocol, one of the gold standard methods to assess circadian amplitude in humans. Radioimmunoassay (RIA) was performed to quantify salivary melatonin. Pearson correlations were performed to examine the associations between 1) ALAN exposure duration and asleep BP and 2) salivary melatonin amplitude and asleep BP. Results: Nine participants with complete data from the parent study were included in the analyses, including 5 women (56%) and 4 men (44%) with a mean age of 39.67 ± 15.11 years. Actigraphy revealed a mean sleep duration of 393.44 ± 77.11 minutes (6.56 hours), mean wake after sleep onset (WASO) of 69.42 ± 78.40 minutes and mean white light exposure equivalent to 713.58 ± 1890.25 lux during the sleep period of ABPM. There was no significant correlation between ALAN exposure duration and asleep systolic BP or diastolic BP, r(7) = .56, p = 0.12; r(7) = .45, p = .23. RIA is ongoing and analyses to determine whether there is a correlation between salivary melatonin amplitude and asleep BP will be presented at the meeting. Conclusions: Preliminary findings suggest that ALAN is not correlated with asleep BP in normotensive Black adults; however, our interpretation is limited by small sample size. Given the existing literature demonstrating a relationship between ALAN and asleep BP in other populations, it is possible that this relationship exists in Black adults. Participants exhibited suboptimal sleep, which may have also contributed to their elevated asleep BP. Findings from the salivary melatonin data will provide helpful insights into a potential circadian mechanism underlying elevated asleep BP. Our study is one of few examining the impact of an environmental determinant of circadian health on cardiovascular health in Black adults.

We evaluated the use of non-invasive faecal testosterone analysis to differentiate between musth and non musth in captive Asian elephants. Twenty male elephants were studied, including five in 'musth' from the Pinnawala Elephant Orphanage (PEO), five privately owned males in musth, and 10 males not in musth from the PEO. Musth was identified by temporal gland swelling and urine dribbling. Faecal samples were collected and analysed using a 125I testosterone radioimmunoassay (RIA) kit. Faecal testosterone levels in elephants in musth were significantly higher than those not in musth but were not different between PEO and privately owned elephants in musth.