Cerebrospinal fluid and plasma concentrations of the inflammatory marker soluble CD27 in a large surgical population.

Soluble CD27 (sCD27) is a potential biomarker for diseases involving immune dysfunction. As there is currently little data on cerebrospinal fluid (CSF) sCD27 concentrations in the general population we measured CSF and plasma concentrations in 486 patients (age range 18-92 years, 57% male) undergoing spinal anesthesia for elective surgery. Across the complete cohort the median [range] sCD27 concentrations were 163 [<50 to 7474] pg/mL in CSF and 4624 [1830 to >400,000] pg/mL in plasma.

Creatine homeostasis and the kidney: comparison between kidney transplant recipients and healthy controls.

Creatine is a natural nitrogenous organic acid that is integral to energy metabolism and crucial for proper cell functioning. The kidneys are involved in the first step of creatine production. With kidney transplantation being the gold-standard treatment for end-stage kidney disease, kidney transplant recipients (KTR) may be at risk of impaired creatine synthesis.

Exploring the kynurenine pathway in mild traumatic brain injury: A longitudinal study.

A potential source of novel biomarkers for mTBI is the kynurenine pathway (KP), a metabolic pathway of tryptophan (Trp), that is up-regulated by neuroinflammation and stress. Considering that metabolites of the KP (kynurenines) are implicated in various neuropsychiatric diseases, exploration of this pathway could potentially bridge the gap between physiological and psychological factors in the recovery process after mTBI. This study, therefore, set out to characterize the KP after mTBI and to examine associations with long-term outcome.

SHBG gene polymorphisms and their influence on serum SHBG, total and free testosterone concentrations in men.

Context: Genetic variation in sex hormone-binding globulin (SHBG) structure may affect estimates of sex steroid exposure by altering the affinity of the protein for its ligand. Consequently, free hormone calculations assuming constant binding affinity may, for certain genetic variations, lead to incorrect diagnoses if genetic variation is not taken into consideration.

Objective: To investigate the effects of genetic variation in SHBG on calculated and measured serum free testosterone (T) in men.

Simultaneous mass spectrometric quantification of trace amines, their precursors and metabolites.

Objectives: Trace amines are powerful neuromodulators influencing the release and reuptake of catecholamines. These low concentrated endogenous amines impact mood, cognition, and hormone regulation. Dysregulation of trace amines have been associated with a variety of diseases, such as schizophrenia, Parkinson's disease, migraine, depression and more.

Association of Fetal Catecholamines With Neonatal Hypoglycemia.

Importance: Perinatal stress and fetal growth restriction increase the risk of neonatal hypoglycemia. The underlying pathomechanism is poorly understood. In a sheep model, elevated catecholamine concentrations were found to suppress intrauterine insulin secretion, followed by hyperresponsive insulin secretion once the adrenergic stimulus subsided.

Discriminatory Value of Steroid Hormones on Polycystic Ovary Syndrome and Clustering of Hyperandrogenism and Metabolic Factors.

Objective: We determined (1) if 11-oxygenated androgens better identify polycystic ovary syndrome (PCOS) diagnosis in women with obesity compared to total or free testosterone (T) and free androgen index; (2) how biochemical hyperandrogenism and metabolic factors cluster in a cohort of women with infertility and obesity.

Methods: Women with obesity and PCOS comprised the study group (N = 132). Ovulatory women with obesity and idiopathic, tubal or male factor infertility were the control group (N = 83).

Effects of endocrine disrupting chemicals and their interactions with genetic risk scores on cardiometabolic traits.

Ubiquitous non-persistent endocrine disrupting chemicals (EDCs) have inconsistent associations with cardiometabolic traits. Additionally, large-scale genome-wide association studies (GWASs) have yielded many genetic risk variants for cardiometabolic traits and diseases. This study aimed to investigate the associations between a wide range of EDC exposures (parabens, bisphenols, and phthalates) and 14 cardiometabolic traits and whether these are moderated by their respective genetic risk scores (GRSs).

Hereditary Alpha Tryptasemia: Validation of a Single-Well Multiplex Digital Droplet PCR Assay in a Cohort of Symptomatic Patients.

Background: Hereditary alpha tryptasemia (HαT) has significant prevalence and potential morbidity in the general population. However, it remains largely undiagnosed in routine clinical diagnostics due to low availability of efficient assessment methods. To address this issue, we developed a reliable and efficient single-well multiplex digital droplet PCR assay.

Quantitative bioanalysis of proteins by digestion and LC-MS/MS: the use of multiple signature peptides.

The use of multiple signature peptides for the quantification of proteins by digestion and LC-MS/MS is reviewed and evaluated here. A distinction is made based on the purpose of the use of multiple peptides: confirmation of the protein concentration, discrimination between different protein forms or species and biotransformation. Most reports that describe methods with at least two peptides use these for confirmation, but it is not always mentioned how the peptides are used and how possible differences in concentration between the peptides are handled.

Sleep quality, fatigue, societal participation and health-related quality of life in kidney transplant recipients: a cross-sectional and longitudinal cohort study.

Background: Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep.

Methods: Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used.

Plasticity in metabolism of maternal androgens in avian embryos.

Mothers can influence offspring phenotypes by transferring non-genetic information to the young, which provides them with a flexible tool to adjust the developmental trajectory of the young in fluctuating environments. Mothers can differentially deposit their resources in the same reproductive attempt in relation to the offspring position in the sibling hierarchy. However, whether embryos from different positions can be plastic in their response to the maternal signals, potentially leading to a mother-offspring conflict, is yet unclear.

Dynamics of maternal androgens and its metabolites during early embryonic development: embryonic modification of a maternal effect.

In birds, exposure to maternal (yolk) testosterone affects a diversity of offspring post-hatching traits, which eventually affect offspring competitiveness. However, maternal testosterone is heavily metabolized at very early embryonic developmental stages to hydrophilic metabolites that are often assumed to be much less biologically potent. Either the rapid metabolism could either keep the maternal testosterone from reaching the embryos, opening the possibility for a mother-offspring conflict or the metabolites may facilitate the uptake of the lipophilic testosterone from the yolk into the embryonic circulation after which they are either converted back to the testosterone or functioning directly as metabolites.

Brain Kynurenine Pathway Metabolite Levels May Reflect Extent of Neuroinflammation in ALS, FTD and Early Onset AD.

Objectives: Despite distinct clinical profiles, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients share a remarkable portion of pathological features, with a substantial percentage of patients displaying a mixed disease phenotype. Kynurenine metabolism seems to play a role in dementia-associated neuroinflammation and has been linked to both diseases. We aimed to explore dissimilarities in kynurenine pathway metabolites in these early onset neurodegenerative disorders in a brain-region-specific manner.

Concentration gradients of monoamines, their precursors and metabolites in serial lumbar cerebrospinal fluid of neurologically healthy patients determined with a novel LC-MS/MS technique.

Background: Potential biomarkers for neuropsychiatric disorders are cerebrospinal fluid (CSF) monoamines and their corresponding precursors and metabolites. During CSF sampling, CSF flows towards the lumbar sampling site from more cranial regions. To compare the results of studies in which different CSF volumes were acquired, it is important to know if ventricular-lumbar concentration gradients exist.

An antibody-free LC-MS/MS method for the quantification of sex hormone binding globulin in human serum and plasma.

Objectives: Sex hormone binding globulin (SHBG) is a hormone binding protein which plays an important role in regulating the transport and availability of biologically active androgens and estradiol to target cells and used to calculate free testosterone concentrations.

Methods: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed, featuring an albumin removal step followed by a tryptic digestion. After a reduction step with dithiothreitol and alkylation with iodoacetamide three signature peptides were used for the quantification of SHBG.

Urinary concentrations of bisphenols and parabens and their association with attention, hyperactivity and impulsivity at adolescence.

Background: Neurobehavioural disorder diagnoses have been increasing over the last decades, leading to heightened interest in the aetiological factors involved. Endocrine disrupting chemicals, such as parabens and bisphenols, have been suggested as one of those factors. It is unknown whether exposure during adolescence may affect neurobehavioural development.

Reference intervals for plasma, urinary, and salivary concentrations of free metanephrines in dogs: Relevance to the diagnosis of pheochromocytoma.

Background: Measurement of free metanephrines is recommended for screening of pheochromocytoma (PCC) but requires appropriate reference intervals (RIs).

Hypothesis/objectives: To report RIs for plasma, urinary and salivary concentrations of free metanephrines and to determine the diagnostic performance of plasma free normetanephrine (pNMN) and metanephrine (pMN) concentrations in dogs with PCC, hypercortisolism (HC), and nonadrenal illness (NAI).

Animals: Eighty healthy dogs, 11 PCC dogs, 25 HC dogs, 6 NAI dogs.

Dietary lithium intake, graft failure and mortality in kidney transplant recipients.

Background: Long-term high-dose lithium therapy in bipolar disorder is known to adversely affect kidney function. However, recent animal studies have revealed that low amounts of lithium are beneficial for the kidney when it is damaged by exposure to nephrotoxic compounds, inflammation or oxidative stress. This study aimed to investigate whether urinary lithium excretion, reflecting dietary lithium intake, is associated with adverse long-term kidney graft outcomes and patient survival.

Circulating FGF21 Concentration, Fasting Plasma Glucose, and the Risk of Type 2 Diabetes: Results From the PREVEND Study.

Objective: Fibroblast growth factor 21 (FGF21) is a peptide hormone synthesized by several organs and regulates, among others, energy homeostasis. In obesity, insulin resistance and type 2 diabetes (T2D), higher circulating FGF21 concentrations have been found. Temporal analyses in murine studies demonstrate that FGF21 increases before insulin resistance occurs.

Clinical irrelevance of lower titer thyroglobulin autoantibodies in patients with differentiated thyroid carcinoma.

Objective: Thyroglobulin (Tg) is an established tumor marker for differentiated thyroid carcinoma (DTC) patients. However, Tg immunoassays can be subject to Tg autoantibody (TgAb) interference resulting in incorrect Tg values. Therefore, Tg measurement with liquid chromatography-tandem mass spectrometry (LC-MS/MS) could be promising in patients with TgAbs.