Pre-analytical stability and physiological fluctuations affect plasma steroid hormone outcomes: A real-world study.

Since steroids are crucial for diagnosing endocrine disorders, the lack of research on factors that affect hormone levels makes interpreting the results difficult. Our study aims to assess the stability of the pre-analytical procedure and the impact of hormonal physiological fluctuations using real-world data. The datasets were created using 12,418 records from individuals whose steroid hormone measurements were taken in our laboratory between September 2019 and March 2024.

A comprehensive LC-MS/MS method for the simultaneous measurement of 24 adrenal steroids: From research to clinical practice.

Steroids are essential in the differential diagnosis of congenital adrenal hyperplasia (CAH) subtypes; however, they may confuse physicians with multifarious results. In this study, we established a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous measurement of 24 steroids and developed a steroid metabolite pathway-based report to aid physicians in understanding these results. Solid-phase extraction was used to concentrate and purify target plasma steroids.

Nightshift work can induce oxidative DNA damage: a pilot study.

Background: Regular sleep is very important for human health; however, the short-term and long-term effects of nightshift with sleep deprivation and disturbance on human metabolism, such as oxidative stress, have not been effectively evaluated based on a realistic cohort. We conducted the first long-term follow-up cohort study to evaluate the effect of nightshift work on DNA damage.

Methods: We recruited 16 healthy volunteers (aged 33 ± 5 years) working night shifts at the Department of Laboratory Medicine at a local hospital.

Reference intervals for LC-MS /MS measurements of plasma renin activity, aldosterone, angiotensin II, and 24-hour urinary aldosterone in Northern Chinese Han population.

Background: Examination of aldosterone to Renin Ratio (ARR) and plasma aldosterone concentration (PAC) or 24-h urinary aldosterone excretion (24-h UALD) was the necessary tests in confirmatory tests for primary aldosteronism (PA). We developed a combined liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for plasma renin activity (PRA), PAC, and angiotensin II (Ang II) and investigated their reference intervals (RIs) in northern Chinese Han population. The RIs of 24-h UALD excretion were also studied using LC-MS/MS.

A robust LC-MS/MS method to measure 8-oxoGuo, 8-oxodG, and NMN in human serum and urine.

Objective: To establish and validate a robust LC-MS/MS method for simultaneously measuring 8-oxoGuo, 8-oxodG, and NMN in serum and urine to evaluate the oxidative stress status.

Methods: A Waters TQ-XS triple quadrupole mass spectrometer system coupled with an Acquity UPLC Primer HSS T3 column was chosen. The clinical performance was verified according to the CLSI C62-A and EP-15 guidelines.

An automated magnetic bead extraction method for measuring plasma metanephrines and 3-methoxytyramine using liquid chromatography tandem mass spectrometry.

Liquid chromatography tandem mass spectrometry (LC-MS/MS) is used routinely in clinical diagnostics; however, automating the sample pretreatment is challenging. We established and evaluated an automated method based on the magnetic bead extraction principle (MBE) to measure normetanephrine (NMN), metanephrine (MN), and 3-methoxytyramine (3-MT). The target analytes were extracted, purified, and concentrated using different solvents and chemical bond-modified magnetic beads transferred via a magnetic bar.

A robust method for simultaneous measurement of serum 25(OH)D, 1,25(OH) D, and 24,25(OH) D by liquid chromatography-tandem mass spectrometry with efficient separation of 3-epi analogs, 23R,25(OH) D , and 4β,25(OH) D.

Background: This study aimed to establish a robust, simple method to detect 25-hydroxyvitamin D (25(OH)D ), 25-hydroxyvitamin D (25(OH)D ), 1,25-dihydroxyvitamin D (1,25(OH) D ), 1,25-dihydroxyvitamin D (1,25(OH) D ), 24,25-dihydroxyvitamin D (24,25(OH) D ), and 24,25-dihydroxyvitamin D (24,25(OH) D ) simultaneously with efficient separation of 3-epi 25(OH)D , 3-epi 24,25(OH) D , 23R,25(OH) D , and 4β,25-dihydroxyvitamin D (4β,25(OH) D ) by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Method: This method was validated according to procedures established by Clinical and Laboratory Standards Institute (CLSI) and then applied in healthy population to determine the distribution of the vitamin D metabolites by LC-MS/MS.

Results: The total-run CV% of 25(OH)D , 25(OH)D , 24,25(OH) D , 24,25(OH) D , 1,25(OH) D , and 1,25(OH) D were 6.

Endocrine pheromones couple fat rationing to dauer diapause through HNF4α nuclear receptors.

Developmental diapause is a widespread strategy for animals to survive seasonal starvation and environmental harshness. Diapaused animals often ration body fat to generate a basal level of energy for enduring survival. How diapause and fat rationing are coupled, however, is poorly understood.

Analytical and Clinical Performance of a Liquid Chromatography-Tandem Mass Spectrometry Method for Measuring Gastrin Subtypes G34 and G17 in Serum.

Background: Two major forms of gastrin, gastrin-17 (G17) and gastrin-34 (G34), exist in blood. However, conventional immunoassay methods can only quantify total gastrin or G17 alone. Here, we aimed to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify G17 and G34 simultaneously.

Plasma or serum, which is the better choice for the measurement of metanephrines?

Measurement of metanephrines (MNs: metanephrine [MN] and normetanephrine [NMN]) is recommended for the initial biochemical diagnosis of pheochromocytoma and paraganglioma. Despite some drawbacks, plasma is commonly used for sampling. Here, we determined the feasibility of using serum, as an alternative to plasma, by comparing MNs in plasma and serum and evaluating the stability of MNs in serum.

Short-term biological variation and Reference change values of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine.

Aim: The DNA and RNA oxidative damage products urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-odGsn) and 8-oxo-7,8-dihydroguanosine (8-oGsn) have potential use in clinical practice. However, biological variation (BV) and reference change values (RCVs) have not been established. The aim of this study was to establish the short-term between-subject BV(CV ) within-subject BV(CV ), and RCVs for urinary 8-odGsn and 8-oGsn.

Validation of an improved liquid chromatography tandem mass spectrometry method for rapid and simultaneous analysis of plasma catecholamine and their metabolites.

Catecholamines [dopamine (DA), epinephrine (E), and norepinephrine (NE)] and their metabolites [metanephrine (MN), normetanephrine (NMN), and 3-methoxytyramine (3-MT)] are functionally important in humans. Their overexpression can indicate the presence of neuroendocrine tumors. Accurate and rapid quantitation of catecholamines and their metabolites may function in differential diagnosis of neuroendocrine tumors.

Sources of variation evaluation of 24,25(OH)2D levels and the ratio of 25OHD to 24,25(OH)2D in apparently healthy Chinese adults: a multicenter cross-sectional study.

24,25(OH)D and the 25OHD/24,25(OH)D ratio have recently been shown to be useful for screening for hypercalcemia caused by CYP24A1 mutations. However, no population-based data on 24,25(OH)D have been published for Chinese populations, and few studies evaluated the sources of variation on 24,25(OH)D levels and the 25OHD/24,25(OH)D ratio. Hence, in 2018, we enrolled 1211 apparently healthy adults without systematic diseases from six representative cities in China (Beijing, Dongying, Guiyang, Urumqi, Shenzhen, and Qiqihar).

Rapid liquid chromatography-tandem mass spectrometry to determine very-long-chain fatty acids in human and to establish reference intervals for the Chinese population.

Very-long-chain fatty acids (VLCFAs), including hexacosanoic, tetracosanoic, and docosanoic acids, are peroxisomal disease markers, whose abnormal accumulation warrants prompt detection for timely, effective treatment. This study aimed to establish and validate a robust liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method to simultaneously quantify VLCFAs and provide reference intervals among Chinese individuals, quantify VLCFAs in pregnancy, and explore potential associations between plasma and amniotic fluid. Analytes were extracted via water-bath incubation with HCl and liquid-liquid extraction.

A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans.

To identify genes that regulate the dynamics of lipid droplet (LD) size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 10(5) mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm.