High-performance Tandem Mass Spectrometry Research Articles

Elimination patterns of dimetridazole in egg of laying hens and tissues of broiler after oral administration

Dimetridazole (DMZ) is a broad-spectrum anti-anaerobic and antiprotozoal drug extensively used for the control of blackhead disease in poultry (especially turkeys). The presence of DMZ and its metabolites in animal food poses potential risks to human health. In this study, we developed a high-performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) method for the precise detection of DMZ and its metabolite 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI). Our results demonstrate a strong linear relationship (r2 > 0.99) between the concentrations of DMZ and HMMNI in tissues and egg within the range of 1~100 ng/g. The limits of detection (LOD) were determined to be 0.5 ng/g, with corresponding limits of quantification (LOQ) at 1.0 ng/g. Furthermore, average recoveries in tissues and egg fell within the range of 84.90% to 103.01%, with coefficients of variation below 15% for both intra-day and inter-day analyses. To investigate the residue elimination pattern of DMZ and HMMNI, diets containing 500 mg/kg DMZ were fed to healthy SanHuang chicken and Hy-line Gray laying hens for 10 consecutive days. The results indicated that the concentration of HMMNI consistently exceeded that of DMZ during the same period, in both broiler tissues and egg. Sebum showed the slowest elimination of DMZ and HMMNI, becoming undetectable after 168 h of withdrawal. In egg, residues of both substances peaked on the first day after drug withdrawal, followed by slow elimination with half-lives of 0.45 days for DMZ and 0.66 days for HMMNI. Based on these findings, WT1.4 software was used to calculate a withdrawal time of 11 days for broilers and an egg abandonment period of 14 days after withdrawal for laying hens, providing a scientific basis for the safe and rational use of DMZ in poultry farming.

Improved high-performance liquid chromatography tandem mass spectrometry method for quantification of infliximab in pediatric plasma and its application in therapeutic drug monitoring.

The application of infliximab (IFX) to immune-mediated disease is limited by the significant individual variability and associated clinical nonresponse, emphasizing the importance of therapeutic drug monitoring (TDM). Because of the cross-reactivity, limited linear range, and high costs, the clinical application of the previous reported methods was limited. Here, an improved high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to address the issues. This study developed an improved bioanalytical HPLC-MS/MS method coupling nanosurface and molecular-orientation limited proteolysis technology. The commercially available compound P14R was selected as the internal standard. This method was developed with fewer volume of reagents and was thoroughly validated. The validated method was applied to TDM in pediatric inflammatory bowel disease (IBD). Chromatography was performed using a Shim-pack GISS-HP C18 metal-free column (3 μm, 2.1 × 100 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile at 0.4 mL/min. Detection and quantitation were performed using electrospray ionization (ESI) and multiple reaction monitoring in the positive ion mode. The method was validated to demonstrate its selectivity, linearity, accuracy, precision, recovery, matrix effect, and stability. The method exhibited a linear dynamic range of 0.3-100 μg/mL, with intra- and inter-day precision and relative errors below 15%. The recovery and matrix effect were measured as 87.28%-89.72% and 41.98%-67.17%, respectively, which were effectively compensated by the internal standard. A total of 32 samples collected from 24 pediatric patients with IBD were analyzed using the validated method, and only 46.9% achieved the reported targeted trough level. This study developed an improved HPLC-MS/MS method for the quantitative determination of IFX concentration in human plasma. The accurate, reliable, and cost-effective method was validated and utilized in the analysis of clinical samples. The results confirmed the importance of TDM on IFX and the clinical application prospects of the improved method.

Comparison Between Twenty-Four-Hour Collection and Single Spot Urines for the Detection of Biogenic Amines by High-Performance Liquid Chromatography Tandem Mass Spectrometry

Comparison Between Twenty-Four-Hour Collection and Single Spot Urines for the Detection of Biogenic Amines by High-Performance Liquid Chromatography Tandem Mass Spectrometry

Endocrine effect of phthalate metabolites and a butterfly effect of prenatal exposure to androgens on qualitative aspects of female sexual response- an initial survey.

There is growing evidence that endocrine disruptive chemicals have deleterious effects on sexual and reproductive function. To examine subjective sexual functions in human females and their relationship to postnatal phthalate exposure and perinatal androgenization, a Sexuality Score (SS) was established from a first-stage survey questionnaire of subjective sexual function filled out by female university students (n = 68; average age 25.23 ± 5.17 years; rural 25.51 ± 6.74 vs. urban 25.85 ± 1.43 years). Seventeen phthalate metabolites in urine samples were analyzed by high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). Females were also assessed for the 2D:4D digit ratio as an index of perinatal androgenization. The mean age of menarche was 12.82 ± 1.35 years (rural 12.59 ± 1.39 vs. urban 13.18 ± 1.27; p = 0.01). The mean age at first sexual intercourse was 14.88 ± 6.89 years (rural 14.62 ± 7.20 vs. urban 15.24 ± 6.55), and as the age of first sexual intercourse increases, the SS score tends to increase as well, albeit moderately (r = 0.25, p = 0.037). Mono-iso-butyl phthalate, mono(2-ethyl-5-carboxypentyl) phthalate, mono(hydroxy-n-butyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate (p ≤ 0.05) and mono(2-carboxymethylhexyl) phthalate (p ≤ 0.01) were negatively associated with SS. A compounding butterfly effect of prenatal exposure to androgens was observed with disruptive effects of mono(2-ethyl-5-oxohexyl) phthalate and mono(2-ethyl-5-carboxypentyl) phthalate on sexual function. Exposure to phthalates in adult females may lead to disruption of subjective sexual function, especially concerning sexual desire and sexual satisfaction, and perinatal androgenization could augment these effects.

A Sensitive Assay for Unbound Docetaxel Using Ultrafiltration plus HPLC-MS and Its Application to a Clinical Study.

Docetaxel, a taxane used in the treatment of solid tumours, exerts pharmacological activity when in its unbound form. We report a sensitive assay to quantify unbound docetaxel after oral administration of docetaxel plus encequidar (oDox+E). Unbound drug quantification is important due to its direct correlation with drug-related toxicity and therapeutic efficacy. We improve on the sensitivity of current assay methods and demonstrate the utility of the assay on a novel formulation of oral docetaxel. Ultrafiltration followed by high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) was utilized. Long-term stability, precision, accuracy, and recovery experiments were conducted to validate the assay. Additionally, patient samples from a Phase I dose-escalation pharmacokinetic study were analyzed using the developed assay. The assay method exhibited long-term stability with an observed change between 0.8 and 6.9% after 131 days of storage at -60 °C. Precision and accuracy quality controls met the FDA acceptance criteria. An average recovery of 88% was obtained. Patient sample analysis demonstrated successful implementation of the assay. A validated sensitive assay was developed with an LLOQ of 0.084 ng/mL using 485 µL of human plasma. The sensitivity of the assay allowed quantification of unbound docetaxel concentrations in an early-phase oDox+E clinical study to compare it against IV docetaxel using pharmacokinetic modelling. Successful development of oDox+E represents an opportunity to replace the current IV docetaxel regimen with an oral regimen with lower cost, decreased side effects, and improve patient quality of life and experience.

Enrichment and Evaluation of Antitumor Properties of Total Flavonoids from Juglans mandshurica Maxim.

Flavonoids are important secondary metabolites found in Juglans mandshurica Maxim., which is a precious reservoir of bioactive substances in China. To explore the antitumor actions of flavonoids (JMFs) from the waste branches of J. mandshurica, the following optimized purification parameters of JMFs by macroporous resins were first obtained. The loading concentration, flow rate, and loading volume of raw flavonoid extracts were 1.4 mg/mL, 2.4 BV/h, and 5 BV, respectively, and for desorption, 60% ethanol (4 BV) was selected to elute JMFs-loaded AB-8 resin at a flow rate of 2.4 BV/h. This adsorption behavior can be explained by the pseudo-second-order kinetic model and Langmuir isotherm model. Subsequently, JMFs were identified using Fourier transform infrared combined with high-performance liquid chromatography and tandem mass spectrometry, and a total of 156 flavonoids were identified. Furthermore, the inhibitory potential of JMFs on the proliferation, migration, and invasion of HepG2 cells was demonstrated. The results also show that exposure to JMFs induced apoptotic cell death, which might be associated with extrinsic and intrinsic pathways. Additionally, flow cytometry detection found that JMFs exposure triggered S phase arrest and the generation of reactive oxygen species in HepG2 cells. These findings suggest that the JMFs purified in this study represent great potential for the treatment of liver cancer.

Simultaneous Screening of 172 Veterinary Drugs by Modified QuEChERS-LC-MS/MS in TCM Galli Gigerii Endothelium Corneum.

An analytical method was developed for the screening of 172 veterinary drugs in traditional Chinese medicine Galli Gigerii Endothelium Corneum by high-performance liquid chromatography tandem mass spectrometry. The samples were pretreated by a modified QuEChERS method. A Zorbax Eclipse plus C18 column (1.8μm, 3.0 × 150mm2, Agilent) was used for the separation of analytes by gradient elution. All analytes were detected by electrospray ionization mass spectrometry with multiple reaction monitoring mode. Good linearity with R ≥ 0.99 was exhibited for all analytes within the respective range. The recoveries of all monitored analytes ranged from 55.4 to 127.6% at three spiked levels (limit of quantitation-LOQ, 2-fold LOQ, 10-fold LOQ), with relative standard deviations <17.8%. The estimated LOQ levels were 0.2-20μg/kg. The application of this method provides a reference for the safety control of traditional Chinese medicines.

N-oleoyl alanine attenuates nicotine reward and spontaneous nicotine withdrawal in mice

BackgroundAs nicotine dependence represents a longstanding major public health issue, new nicotine cessation pharmacotherapies are needed. Administration of N-oleoyl glycine (OlGly), an endogenous lipid signaling molecule, prevents nicotine-induced conditioned place preference (CPP) through a peroxisome proliferator-activated receptor-alpha (PPARα) dependent mechanism, and also ameliorated withdrawal signs in nicotine-dependent mice. Pharmacological evidence suggests that the methylated analog of OlGly, N-oleoyl alanine (OlAla), has an increased duration of action and may offer translational benefit. Accordingly, OlAla was assessed in nicotine CPP and dependence assays as well as its pharmacokinetics compared to OlGly. MethodsICR female and male mice were tested in nicotine-induced CPP with and without the PPARα antagonist GW6471. OlAla was also assessed in nicotine-dependent mice following removal of nicotine minipumps: somatic withdrawal signs, thermal hyper-nociception and altered affective behavior (i.e., light/dark box). Finally, plasma and brain were collected after administration of OlGly or OlAla and analyzed by high-performance liquid chromatography tandem mass spectrometry. ResultsOlAla prevented nicotine-induced CPP, but this effect was not blocked by GW6471. OlAla attenuated somatic and affective nicotine withdrawal signs, but not thermal hyper-nociception in nicotine-dependent mice undergoing withdrawal. OlAla and OlGly showed similar time-courses in plasma and brain. ConclusionsThe observation that both molecules showed similar pharmacokinetics argues against the notion that OlAla offers increased metabolic stability. Moreover, while these structurally similar lipids show efficacy in mouse models of reward and dependence, they reduce nicotine reward through distinct mechanisms.

Recent advances in high-performance liquid chromatography tandem mass spectrometry techniques for analysis of DNA damage and epigenetic modifications

Environmental exposure would cause DNA damage and epigenetic modification changes, potentially resulting in physiological dysfunction, thereby triggering diseases and even cancer. DNA damage and epigenetic modifications are thus promising biomarkers for environmental exposures and disease states. Benefiting from its high sensitivity and accuracy, high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is considered the “gold standard technique” for investigating epigenetic DNA modifications. This review summarizes the recent advancements of UHPLC-MS/MS-based technologies for DNA damage and epigenetic modifications analysis, mainly focusing on the innovative methods developed for UHPLC-MS/MS-related pretreatment technologies containing efficient genomic DNA digestion and effective removal of the inorganic salt matrix, and the new strategies for improving detection sensitivity of liquid chromatography-mass spectrometry. Moreover, we also summarized the novel hyphenated techniques of the advanced UHPLC-MS/MS coupled with other separation and analysis methods for the measurement of DNA damage and epigenetic modification changes in special regions and fragments of chromosomes.

Nontargeted lipidomics of Florida seagrasses

Seagrasses are one of the most productive foundation species in the world and are important for maintaining ecosystem homeostasis. However, seagrasses have experienced a global decline in areal extent, due in part to environmental stressors. Despite ongoing decline, little is known about the lipidome of most seagrass species. Generally, lipidome profiles closely align with phenotypic changes and can be used to evaluate the condition of an individual. In this study, a nontargeted lipidomics approach, utilizing high-performance liquid chromatography tandem mass spectrometry, was used to assess the lipidome of wild seagrasses in Florida. Overall, 399 individual lipid species, comprised of 33 lipid subclasses, were identified across all specimens. The lipid classes with the highest total concentration, accounting for 75% of total identified lipids in all seagrasses were: monogalactosyldiacylglycerols (MGDG), digalactosyldiacylglycerols (DGDG), and sulfoquinovosyl diacylglycerols (SQDG). Here, the lipidomic profiles of wild seagrasses were identified for the first time, a necessary step toward using lipodomics as a tool for prospective assessments of condition. Once regional and species-specific baselines have been mapped, lipodomic surveys could provide new insight into the effects of environmental stressors on seagrass condition and help to augment ongoing efforts to document and understand seagrass ecosystem status and trends.

In vitro, invivo metabolism and quantification of the novel synthetic opioid N-piperidinyl etonitazene (etonitazepipne).

N-piperidinyl etonitazene (etonitazepipne) is a newly synthesized opioid related to the 2-benzylbenzimidazole analog class. Etonitazepipne has been formally notified and placed under intensive monitoring in Europe in January 2022. Nitazenes have high affinity at µ-opioid receptor (MOR). Etonitazepipne, specifically shows a EC50 of 2.49 nM, suggesting about 50 times higher potency combined with higher efficacy compared to morphine. Antinociceptive potency l ('hot plate test' with rats) was 192-fold greater than that of morphine. Here we report on a post-mortem case involving etonitazepipne and its quantification using a standard addition method (SAM) through liquid chromatography tandem mass spectrometry (LC-MS/MS). In addition, characterization and identification of phase I human metabolites using invitro assay based on pooled human liver microsomes (pHLM) was performed along with the analysis of authentic urine samples by means of high-performance liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). The concentration of etonitazepipne in post-mortem blood and urine was 8.3 and 11 ng/mL, respectively. SAM was validated by assessing the following parameters: intraday and interday repeatability, matrix effect and recovery rate in post-mortem blood. A total of 20 and 14 metabolites were identified after pHLM incubation and urine analysis, respectively. Most pronounced invitro and invivo transformations were O-deethylation, hydroxylation, ketone reduction, and combinations thereof. Considering small traces of the parent drug often found in real cases, the identification of metabolic biomarkers is crucial to identify exposure to this drug. O-deethylated, oxidated metabolites, and combination thereof are proposed as urinary biomarkers along with the parent compound.

Cross sectional study on exposure to BPA and its analogues and semen parameters in Czech men

Exposure to bisphenols has been found to have adverse effects on male reproductive function in animals. Human exposure to bisphenols is widespread. Bisphenol A (BPA) and its analogues, including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF) are utilized in various consumer products such as food contact materials and dental resins. The effects of these compounds on male fertility and spermatogenesis are unclear and findings from human studies are inconsistent. In this cross-sectional study, we evaluated the influence of BPA, BPS, BPF, BPAF (BPs) measured in semen on number of spermatozoa, total motility, progressive motility, morphology, and DNA fragmentation. We also examined the association of bisphenols (BPs) exposure with patients’ occupation. A total of 358 patients aged 17–62 years with BMI 18–42 were included in the study from 2019 to 2021. BPs were extracted using solvent extraction followed by preconcentration step and determined by high-performance liquid chromatography and tandem mass spectrometry (LC/MSMS). Bisphenols were detected in 343 from 349 analysed samples (98.3% of all the samples). In 6 samples, the concentration of all BPs was under the limit of detection and in 20 samples under the limit of quantification. We did not find a statistically significant relationship between occupation and BPs. However, we observed significant correlations between the concentration of BPA and a lower motility and normal morphology. For BPS, a significant correlation with a lower ejaculate volume and a lower total sperm count was found. BPF and BPAF were detected only in 14.3% and 23.9% of samples, respectively. For BPF and BPAF, no significant correlations with spermiogram parameters were observed. Our results show that BPs are widespread in the male population (more than 90% of analysed samples), independently of an occupation and in case of BPA and BPS having a negative impact on spermiogram parameters.

Association of serum trimethylamine N-oxide levels and bone mineral density in type 2 diabetes mellitus.

The relationship between trimethylamine N-oxide (TMAO) and bone mineral density (BMD) in type 2 diabetes mellitus (T2DM) is unclear. We explore the relationship between TMAO levels and BMD in T2DM. This is a cross-sectional study. 254 T2DM patients were enrolled and divided into three groups by TMAO tertiles, and the clinical data were collected. BMD was determined by dual-energy X-ray absorptiometry (DXA) and serum TMAO levels was determined by stable isotope dilution high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Patients in the highest tertile of TMAO levels (TMAO > 6.72 μmol/L) showed relatively low BMD and a higher number of fracture history, osteoporosis (OP) than those in the lower tertiles. Spearman correlation analysis showed that serum TMAO was negatively correlated with BMD of whole body (WB), lumbar spine (LS) and femoral neck (FN), while TMAO was positive correlated with osteoporotic fracture (p < 0.05). Logistic regression models showed that TMAO was an independent influencing factor of fracture history after adjusting for confounders in TMAO > 6.72 μmol/L group. There is a significant linear correlation between TMAO levels and BMD in T2DM patients. Especially in TMAO > 6.72 μmol/L group, TMAO was negatively correlated with WB, LS, and FN BMD, and was positive correlated with osteoporotic fracture in T2DM patients. The findings suggest that elevated TMAO levels are associated with OP and osteoporotic fracture in T2DM patients.

Formula model established through field application of glass slides and rapid analysis of pesticide residues in vegetables by ion mobility spectrometry

The prevalence of pesticide usage has brought the matter of pesticide residues to the forefront, necessitating the development of effective detection methods as a crucial step towards addressing this issue. This study presents a novel approach for detecting pesticide residues in vegetables using glass slide-formula-ion mobility spectrometry (IMS). The approach enables swift analysis of 36 different pesticides across three vegetable species with glass slides. To establish a formula for calculating pesticide residues in vegetables using glass slides, the vegetable samples and glass slides were placed in a spray tower and evenly sprayed pesticides. The per unit area of glass slides was used to calculate the pesticide loading capacity and total pesticide loading area of vegetables. The original residues were analyzed with ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The field experiment yielded consistent results between the model values of the formula and the actual measured values, with correlation coefficients (R2) ranging from 0.927 to 0.983. The slide-formula model-IMS method was found to be effective for field applications, as it proved to be simple, rapid, and accurate in predicting pesticide residue concentrations in vegetable samples. This approach could be a valuable tool for monitoring pesticide residues in vegetable cultivation globally.

Circulating 3-hydroxy butyrate predicts mortality in patients with chronic heart failure with reduced ejection fraction.

In patients with chronic heart failure with reduced ejection fraction (HFrEF), myocardial ketone metabolism is increased and short-term treatment with the ketone body 3-hydroxy butyrate (3-OHB) has beneficial haemodynamic effects. In patients with HFrEF, we investigated whether the level of circulating 3-OHB predicted all-cause mortality and sought to identify correlations between patient characteristics and circulating 3-OHB levels. We conducted a cohort study in 218 patients with HFrEF. Plasma 3-OHB levels were measured using high-performance liquid chromatography tandem mass spectrometry. Data on all-cause mortality were obtained by reviewing the patients' medical records, which are linked to the national 'Central Person Registry' that registers the timing of all deaths in the country. Mean left ventricular ejection fraction was 35±8.6%, mean age was 67±10years, 54% were New York Heart Association II, and 27% had type 2 diabetes mellitus. Median follow-up time was 7.3 (interquartile range 6.3-8.4) years. We observed large variations in 3-OHB levels between patients (median 59μM, range: 14-694μM). Patients with 3-OHB levels above the median displayed a markedly increased risk of death compared with those with low levels {hazard ratio [HR]: 2.1 [95% confidence interval (CI): 1.3-3.5], P=0.003}. In a multivariate analysis, 3-OHB predicted mortality independently of known chronic heart failure risk factors [HR: 1.004 (95% CI: 1.001-1.007), P=0.02] and with a similar statistical strength as N-terminal pro-brain natriuretic peptide (NT-proBNP) [HR: 1.0005 (95% CI: 1.000-1.001), P=0.02]. For every 100μmol increase in plasma 3-OHB, the hazard of death increased by 49%. The following factors significantly predicted 3-OHB levels in the univariate analysis: free fatty acids (FFAs) [β: 238 (95% CI: 185-292), P<0.0001], age [β: 2.43 (95% CI: 1.14-3.72), P<0.0001], plasma insulin {β: -0.28 [95% CI: -0.54-(-0.02)], P=0.036}, body mass index {β: -3.15 [95% CI: -5.26-(-0.05)], P=0.046}, diabetes [β: 44.49 (95% CI: 14.84-74.14), P=0.003], glycosylated haemoglobin [β: 1.92 (95% CI: 0.24-3.59), P=0.025], New York Heart Association class [β: 26.86 (95% CI: 5.99-47.72), P=0.012], and NT-proBNP [β: 0.03 (95% CI: 0.01-0.04), P=0.001]. In a multivariate analysis, only FFAs predicted 3-OHB levels [β: 216 (95% CI: 165-268), P>0.001]. In patients with HFrEF, circulating 3-OHB was a strong predictor of all-cause mortality independently of NT-proBNP. Circulating FFAs were the best predictor of 3-OHB levels.

Prevalence of carboxy-Δ8 -tetrahydrocannabiniol in antidoping samples.

Δ9 -Tetrahydrocannabinol (Δ9 -THC) is usually the primary psychoactive agent in cannabis preparations. Recently, products containing another isomer, Δ8 -tetrahydrocannabinol (Δ8 -THC), have become available for sale. Δ8 -THC exists naturally in the cannabis plant at very low concentrations; hence, the Δ8 -THC present in most of the above-mentioned products is likely to be manufactured synthetically. A surge in popularity of these products, coupled with little oversight to ensure purity and potency, has led to reports of adverse events. Workplace drug testing programs as well as many sporting organizations prohibit the use of cannabinoids. Carboxy-Δ9 -THC (Δ9 -THC-COOH) is the targeted urinary metabolite for detection of cannabis use. The proliferation of products containing Δ8 -THC, which metabolizes to Δ8 -THC-COOH, presents analytical complexity with respect to separation and quantification of the individual isomers as well as legal complexity with respect to lack of clarity around the legal status of Δ8 -THC. This study aims to estimate the prevalence of Δ8 -THC use in the athlete community by monitoring for Δ8 -THC-COOH in samples collected for antidoping. A high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method was utilized to resolve Δ8 and Δ9 -THC-COOH. One thousand samples with a presumptive Δ9 -THC-COOH finding in routine screening were analyzed by the above LC-MS/MS method. Approximately 12% of samples contained Δ8 -THC-COOH at relative abundances between 5% and 100% of total carboxy-THC content.

Variations in colostrum metabolite profiles in association with sow parity

Abstract Information about the full spectrum of metabolites present in porcine colostrum and factors that influence metabolite abundances is still incomplete. Parity number appears to modulate the concentration of single metabolites in colostrum. This study aimed to 1) characterize the metabolome composition and 2) assess the effect of parity on metabolite profiles in porcine colostrum. Sows (n = 20) were divided into three parity groups: A) sows in parity 1 and 2 (n = 8), B) sows in parity 3 and 4 (n = 6), and C) sows in parity 5 and 6 (n = 6). Colostrum was collected within 12 h after parturition. A total of 125 metabolites were identified using targeted reversed-phase high-performance liquid chromatography-tandem mass spectrometry and anion-exchange chromatography-high resolution mass spectrometry. Gas chromatography additionally identified 19 fatty acids (FAs). Across parities, colostrum was rich in creatine and creatinine, 1,3-dioleyl-2-palmitatoylglycerol, 1,3-dipalmitoyl-2-oleoylglycerol, and sialyllactose. Alterations in colostrum concentrations were found for eight metabolites among parity groups (P &amp;lt; 0.05) but the effects were not linear. For instance, colostrum from parity group C comprised 75.4% more valine but 15.7%, 34.1%, and 47.9% less citric, pyruvic, and pyroglutamic acid, respectively, compared to group A (P &amp;lt; 0.05). By contrast, colostrum from parity group B contained 39.5% more spermidine than from group A (P &amp;lt; 0.05). Of the FAs, C18:1, C16:0, and C18:2 n6 were the main FAs across parities. Parity affected four FAs (C18:3n3, C14:1, C17:0ai, and C17:1), including 43.1% less α-linolenic acid (C18:3n3) in colostrum from parity group C compared to groups A and B (P &amp;lt; 0.05). Signature feature ranking identified 1-stearoyl-2-hydroxy-sn-glycero-3-phosphatidylcholine and the secondary bile acid hyodeoxycholic acid as the most discriminative metabolites, showing a higher variable importance in the projection score in colostrum from parity group A than from groups B and C. Overall, results provided a comprehensive overview about the metabolome composition of sow colostrum. The consequences of the changes in colostrum metabolites with increasing parity for the nutrient supply of the piglets should be investigated in the future. The knowledge gained in this study could be used to optimize feeding strategies for sows.

Association of physical activity and vitamin D deficiency with cognitive impairment in older adults: a population based cross-sectional analysis.

The global aging situation is becoming increasingly critical and cognitive impairment in the elderly has become a public health burden of concern. Physical activity (PA) and vitamin D may play a key role in improving cognitive impairment. However, little studies have examined the interaction between these two. The purpose of this study was to assess the association of PA and vitamin D with cognitive impairment in older adults, as well as the interactions of PA and vitamin D. This study was conducted by multi-stage random sampling of elderly people ≥60 years old, and a total sample of 2,492 (1,207 male and 1,285 female, mean age of 69.41 ± 6.75 years) with complete data was included in the analysis. PA was assessed by the Global Physical Activity Questionnaire, and < 600 MET-min/week was used as the division criteria. Serum vitamin D was measured by high-performance liquid chromatography tandem mass spectrometry, and 25-hydroxyvitamin D2/D3 concentration < 20 ng/mL was used as a vitamin D deficiency criterion. Cognitive function was assessed by three subtests: the Consortium to Establish a Registry for Alzheimer's disease word learning test (CERAD-WL) for immediate and delayed learning, the Animal Fluency Test (AFT) for verbal fluency; and the Digit Symbol Substitution Test (DSST) for information processing speed and switching attention. All three subtests were scored at less than the lowest quartile of the score as a criterion for cognitive impairment. Statistical analysis was performed using SPSS for chi-square test, rank sum test, interaction analysis, subgroup analysis, and regression analysis. Lower level of PA is associated with higher odds of cognitive impairment (CERAD W-L: OR = 1.596, 95% CI: 1.338-1.905, p < 0.001; AFT: OR = 1.833, 95% CI: 1.534-2.190, p < 0.001; DSST: OR = 1.936, 95% CI: 1.609-2.329, p < 0.001). Vitamin D deficiency has significant effects in AFT (OR = 1.322, 95% CI: 1.103-1.584, p = 0.003) and DSST (OR = 1.619, 95% CI: 1.345-1.948, p < 0.001). After adjusted for covariates, PA and vitamin D have multiplicative interaction on AFT (OR = 0.662, 95% CI: 0.448-0.977, p = 0.038) and DSST (OR = 0.775, 95% CI: 0.363-0.868, p = 0.009). The interaction between PA and vitamin D was not significant in the CERAD W-L (OR = 0.757, 95% CI: 0.508-1.128, p = 0.172). The results showed that lower level of PA and vitamin D deficiency were associated with higher odds of cognitive impairment in the elderly population and that there was a multiplicative interaction between PA and vitamin D on cognitive function, with a significant effect of vitamin D on cognitive impairment in high PA conditions.

Association of phthalate exposure with all-cause mortality across renal function status: The U.S. National Health and Nutrition Examination Survey, 2005–2018

BackgroundWide phthalate exposure has been associated with both declines in renal function and an elevated risk of mortality. Whether phthalate-associated risk of premature mortality differs by renal function status remains unclear. MethodsThis study included 9605 adults from the U.S. National Health and Nutrition Examination Survey. Urinary concentrations of 11 phthalate metabolites were assessed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. According to estimated glomerular filtration rate (eGFR), participants were grouped as having normal or modestly declined renal functions, or chronic kidney disease (CKD). Multivariable Cox regression models estimated all-cause mortality associated with phthalate exposure, overall and by renal function status. ResultsOverall, Mono-n-butyl phthalate (MnBP), Mono-benzyl phthalate (MBzP), Mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono-(2-ethyl-5-carbox-ypentyl) phthalate (MECPP) were associated with an elevated risk of mortality (P-trend across tertile <0.05). Moreover, significant interactions were observed between eGFR and MEHHP, MEOHP, MECPP, DEHP in the whole population (P for interactions <0.05). After stratification by renal function, total Di (2-ethylhexyl) phthalate (DEHP) was additionally found to be associated with mortality risk in the CKD group (HR = 1.12; 95% CI: 1.01, 1.25). Co-exposure to the 11 phthalate metabolites was associated with a higher risk of all-cause mortality in the CKD (HR = 1.47; 95% CI: 1.18, 1.84) and modestly declined renal function group (HR = 1.25; 95% CI: 1.09, 1.44). ConclusionsThe associations between phthalate exposure and risk of all-cause mortality were primarily observed in CKD patients, reinforcing the need for monitoring phthalate exposure in this patient population.

Profiling of adenine-derived signaling molecules, cytokinins, in myotubes reveals fluctuations in response to lipopolysaccharide-induced cell stress.

Cytokinins (CTKs) are a diverse collection of evolutionarily conserved adenine-derived signaling molecules classically studied as phytohormones; however, their roles and production have been less studied in mammalian systems. Skeletal muscles are sensitive to cellular cues such as inflammation and in response, alter their secretome to regulate the muscle stem cell and myofiber niche. Using cultured C2C12 muscle cells, we profiled CTK levels to understand (1) whether CTKs are part of the muscle secretome and (2) whether CTKs are responsive to cellular stress. To induce cellular stress, C2C12 myotubes were treated with lipopolysaccharides (LPS) for 24 h and then media and cell fractions were collected for ultra high-performance liquid chromatography tandem mass spectrometry with electrospray ionization (UHPLC-(ESI+)-HRMS/MS) for metabolomics and CTK profiling. Across LPS-treated and control cells, 11 CTKs were detected in the extracellular space while 6 were detected intracellularly. We found that muscle cells are enriched in isopentenyladenine (iP) species (from free base, riboside to nucleotide forms), and that extracellular levels are increased after LPS treatment. Our study establishes that muscle cells express various forms of CTKs, and that CTK levels are responsive to LPS-induced cell stress, suggesting a role for CTKs in intra- and extracellular signaling of mammalian cells.