Performance Liquid Chromatography-tandem Mass Research Articles

Metabolic profiling reveals new serum signatures to discriminate lupus nephritis from systemic lupus erythematosus.

BackgroundLupus nephritis (LN) occurs in 50% of patients with systemic lupus erythematosus (SLE), causing considerable morbidity and even mortality. Previous studies had shown the potential of metabolic profiling in the diagnosis of SLE or LN. However, few metabonomics studies have attempted to distinguish SLE from LN based on metabolic changes. The current study was designed to find new candidate serum signatures that could differentiate LN from SLE patients using a non-targeted metabonomics method based on ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).MethodMetabolic profiling of sera obtained from 21 healthy controls, 52 SLE patients and 43 LN patients. We used SPSS 25.0 for statistical analysis. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and metabolic pathway analysis were used to analyze the metabolic data.ResultsUpon comparison of SLE and LN groups, 28 differential metabolites were detected, the majority of which were lipids and amino acids. Glycerolphospholipid metabolism, pentose and glucuronate interconversions and porphyrin and chlorophyll metabolism were obviously enriched in LN patients versus those with SLE. Among the 28 characteristic metabolites, five key serum metabolites including SM d34:2, DG (18:3(9Z,12Z,15Z)/20:5(5Z,8Z,11Z,14Z,17Z)/0:0), nervonic acid, Cer-NS d27:4, and PC (18:3(6Z,9Z,12Z)/18:3(6Z,9Z,12Z) performed higher diagnostic performance in discriminating LN from SLE (all AUC > 0.75). Moreover, combined analysis of neuritic acid, C1q, and CysC (AUC = 0.916) produced the best combined diagnosis.ConclusionThis study identified five serum metabolites that are potential indicators for the differential diagnosis of SLE and LN. Glycerolphospholipid metabolism may play an important role in the development of SLE to LN. The metabolites we screened can provide more references for the diagnosis of LN and more support for the pathophysiological study of SLE progressed to LN.

Did they really drink alcohol? Key role of ethyl glucuronide and ethyl sulfate in blood and vitreous humour in the interpretation of postmortem alcohol findings

To evaluate the role of ethyl glucuronide (EtG) and ethyl sulphate (EtS) analysis in improving the interpretation of postmortem blood alcohol results. Postmortem ethanol formation is a classic problem in forensic toxicology. EtG and EtS are minority metabolites of ethanol, produced by non-oxidative reactions; they are sensitive and specific markers of ethanol intake that can be useful to distinguish antemortem alcohol intake from postmortem ethanol formation. A sensitive method of EtG and EtS analysis would help to improve the interpretation of questionable alcohol results. EtG and EtS were analysed in whole blood (WB) and vitreous humour (VH), if available, from 48 autopsy cases where ethanol is routinely analysed by headspace gas chromatography with flame ionization detector (GC-FID; Calibration range 0.1–4.0 g/L; LOD 0.04 g/L). WB and VH samples were subjected to protein precipitation, followed by ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS), with the multiple reaction monitoring (MRM) approach in negative mode, for EtG and EtS analysis. Calibration ranges for both analytes were 10–5000 ng/mL; samples were diluted where necessary. Based on ethanol findings and available samples, cases were classified into four groups: – G1: positive results for ethanol in WB and VH, strongly indicative of antemortem alcohol intake ( n = 20, blood alcohol concentration range: 0.1–3.1 g/L, median 1.3 g/L); – G2: no detection of ethanol in WB ( n = 8); – G3: positive results for ethanol in WB, but no detection of alcohol in VH ( n = 12, BAC range: 0.1–> 4.0 g/L, median 0.2 g/L); – G4: positive results for ethanol in WB but VH in poor condition (bloody) or no available VH ( n = 8, BAC range: 0.2–1.9 g/L, median 0.5 g/L). G1: all cases were positive in WB for EtG (range 28–28,314 ng/mL; median 1179 ng/mL) and EtS (range 31–3686 ng/mL; median 450 ng/mL). From cases with HV available for EtG and EtS analysis ( n = 16), 13 were found positive for both analites, two only for EtG and another one only for EtS. G2: EtG and EtS were no detected in WB, nor in HV, in any case. G3: in one of the cases EtG and EtS were positive in WB (131 ng/mL and 181 ng/mL, respectively; BAC 0.13 g/L) and HV. EtG alone was detected in WB and HV in one case, and only in HV in another case. None of them were detected in 9 cases in this group. G4: in two cases EtG and EtS were detected in WB (22,802 ng/mL and 2336 ng/mL, respectively; BAC 1.9 g/L; and 378 ng/mL and 104 ng/mL, respectively; BAC 0.3 g/L) and HV. EtG alone was detected only in WB in one case, and only in HV in another case. None of them were detected in the 4 cases in this group. In most cases from G3 the BAC values were less than 0.4 g/L. Cases with high BAC in this group were deceased with decompensated diabetes and sudden infant deaths; the alcohol detected in blood was probably originated postmortem through microbiological fermentation. Seven cases in G4 were corpses found 1–10 days after death, with variable degree of putrefaction and high risk of postmortem generation of alcohol. Antemortem alcohol intake could be stablished where EtS was detected, taking into account that EtG can be both produced and degraded by microorganisms. The joint analysis of EtG and EtS in postmortem blood and vitreous humour samples plays a key role in the interpretation of most cases where antemortem alcohol intake remains doubtful from the available data of blood alcohol concentration.

Effective enrichment and detection of bisphenol diglycidyl ether, novolac glycerol ether and their derivatives in canned food using a novel magnetic sulfonatocalix[6]arene covalent cross-linked polymer as the adsorbent

A core–shell magnetic sulfonatocalix[6]arene covalently cross-linked polymer was proposed as a magnetic adsorbent, combined with ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the enrichment and determination of epoxy derivatives in canned foods. The adsorbent has high density of host–guest recognition functional groups, abundant binding sites and suitable cavity size, showing good extraction performance for epoxy derivatives. Quantum chemical simulation calculations provedmultiple interaction forces in the adsorption process. Theextractionparameterswere investigated. Under optimized experimental conditions, 13 kinds of target analytes showed low detection limits (0.0072–0.023 ng/g) and good precisions (RSDs of 0.8 %-9.4 %). This method has been successfully applied to the simultaneous determination of 13 kinds of epoxy derivatives in different food samples including canned beverage, fish, meat, and milk powder. Satisfactory recoveries (74.9 %–118 %) were obtained. The results showed the potential application prospects in the enrichment and detection of hazardous substances in food.

Differential expression of cystathionine beta synthase in adolescents with Down syndrome: impact on adiposity.

Obesity is more prevalent among people with Down Syndrome (DS) compared to general population. In this pilot study, we investigated the effect of cystathionine beta-synthase (CBS) overdosage on the regulation of transsulfuration pathway and the obesity phenotype in fifty adolescents (25 obese/overweight and 25 lean) with trisomy 21. The transcriptional levels of CBS in leukocytes and its translational levels in plasma were quantified using real time polymerase chain reaction and enzyme-linked immunosorbent assay respectively. Meanwhile, ultra performance liquid chromatography tandem mass spectrometry was used to determine the plasma concentrations of methionine, homocysteine, cystathionine and cysteine. Fasting plasma lipid profiles were assessed by colorimetric assays. The anthropometric measurements and indices of all subjects were recorded. Both DS groups had comparable levels of CBS transcripts (p = 0.2734). The plasma levels of the enzyme were significantly higher in the lean DS cases (p = 0.0174) compared to the obese/overweight participants. Total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, methionine, homocysteine, cystathionine and cysteine showed similar plasma levels in both groups. However, the plasma cysteine levels exceeded the normal range in all DS cases. We reported a statistically significant inverse association between CBS enzyme levels and weight (r= - 0.3498, p = 0.0128), hip circumference (r= - 0.3584, p = 0.0106), body mass index (r= - 0.3719, p = 0.0078) and body adiposity index (r= - 0.3183, p = 0.0243). Our data suggests that the high concentrations of CBS enzyme together with cysteine modulate the DS obesity presumably through increased hydrogen sulfide production which has recently showed anti-adiposity effects.

Rapid determination of nitrofuran metabolites residues in honey by ultrasonic assisted derivatization - QuEChERS - high performance liquid chromatography / tandem mass spectrometry

In this study, a method of ultrasonic assisted derivatization combined with improved QuEChERS scheme and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was developed for the analysis of nitrofuran metabolite residues in honey samples. The optimized conditions such as ultrasonic assisted derivatization conditions, extraction methods and purification materials quantitatively obtained by matrix standard curve external standard method had finally been proved to be effective in the determination of nitrofuran metabolite residues in honey samples. In order to make the results more accurate, the matrix matched standard for isotope-labeled internal standard method was used for methodological verification. The concentration of all target substances ranged from were 0.25–20 ng/mL, with good linearity, and the correlation coefficient were 0.9999. The LOD and LOQ of the target analyte were 0.15 and 0.5 μg/kg respectively. The average recoveries of the three standards were between 1.89 % and 107.9 %. The recoveries of inter-day and intra-day tests were 96.0–100.2 % and 93.2–98.7 % respectively. The precisions of inter-day(n = 6) and intra-day(n = 6) analysis were 3.56–5.29 % and 3.09–5.13 % respectively. 85 honey samples obtained from the market were analyzed by our optimized method, of which 4 SEM and 1 AOZ were detected in 5 samples.

Dominant changes in the breast muscle lipid profiles of broiler chickens with wooden breast syndrome revealed by lipidomics analyses

BackgroundChicken is the most consumed meat worldwide and the industry has been facing challenging myopathies. Wooden breast (WB), which is often accompanied by white striping (WS), is a serious myopathy adversely affecting meat quality of breast muscles. The underlying lipid metabolic mechanism of WB affected broilers is not fully understood.ResultsA total of 150 chickens of a white-feathered, fast-growing pure line were raised and used for the selection of WB, WB + WS and control chickens. The lipids of the breast muscle, liver, and serum from different chickens were extracted and measured using ultra performance liquid chromatography (UPLC) plus Q-Exactive Orbitrap tandem mass spectrometry. In the breast, 560 lipid molecules were identified. Compared to controls, 225/225 of 560 lipid molecules (40.2%) were identified with differential abundance (DA), including 92/100 significantly increased neutral lipids and 107/98 decreased phospholipids in the WB/WB + WS groups, respectively. The content of monounsaturated fatty acids (MUFA) was significantly higher, and the polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) were significantly lower in the affected breasts. In the liver, 434 lipid molecules were identified, and 39/61 DA lipid molecules (6.7%/14.1%) were detected in the WB and WB + WS groups, respectively. In the serum, a total of 529 lipid molecules were identified and 4/44 DA lipid molecules (0.8%/8.3%) were detected in WB and WB + WS group, respectively. Compared to controls, the content of MUFAs in the serum and breast of the WB + WS group were both significantly increased, and the content of SFAs in two tissues were both significantly decreased. Only five lipid molecules were consistently increased in both liver and serum in WB + WS group.ConclusionsWe have found for the first time that the dominant lipid profile alterations occurred in the affected breast muscle. The relative abundance of 40.2% of lipid molecules were changed and is characteristic of increased neutral lipids and decreased phospholipids in the affected breasts. Minor changes of lipid profiles in the liver and serum of the affected groups were founded. Comprehensive analysis of body lipid metabolism indicated that the abnormal lipid profile of WB breast may be independent of the liver metabolism.

Rapid and accurate quantification and analysis of nitrofuran metabolites residues in aquatic products by ultra-high performance liquid chromatography–tandem mass spectrometry

Rapid and accurate quantification and analysis of nitrofuran metabolites residues in aquatic products by ultra-high performance liquid chromatography–tandem mass spectrometry

HPLC–MS/MS method for the simultaneous determination of aflatoxins in blood: toxicokinetics of aflatoxin B1 and aflatoxin M1 in rats

Mycotoxins are highly toxic fungal metabolites that can pose health threats to humans and animals. Aflatoxins are a type of mycotoxin produced mainly by Aspergillus flavus and A. parasiticus. A sensitive high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method with multiple reaction monitoring (MRM) modes was developed for the determination of aflatoxins in blood after acetonitrile precipitation extraction. The limits of quantification of aflatoxins ranged from 0.05 to 0.2 ng/mL. Intra-day accuracy ranged from 92 to 111.0%, and intra-day precision (n = 6) ranged from 1 to 8%. Inter-day accuracy and precision were 94.0–102.0% and 2.0–8.0%, respectively. The toxicokinetics of AFB1 and its metabolite AFM1 after a single oral administration (AFB1 1 mg/kg body weight) were studied in male Sprague–Dawley rats. The blood AFB1 and AFM1 profiles could be adequately described by a noncompartmental model. The highest concentration of AFB1 (Cmax 93.42 ± 23.01 ng/mL) was observed with Tmax at 0.15 ± 0.034 h. AFB1 was rapidly metabolized to AFM1 which reached its peak blood concentration (Cmax 53.86 ± 12.12 ng/mL) at 0.33 ± 0.11 h. The HPLC–MS/MS method was simple and sensitive, appropriate for studying the in vivo toxicokinetics of aflatoxins.

Development and validation of an LC-MS/MS method for the quantification of mescaline and major metabolites in human plasma

Mescaline is a psychedelic phenethylamine found in different species of cacti. Currently, mescaline’s acute subjective effects and pharmacokinetics are investigated in several modern clinical studies. Therefore, we developed a bioanalytical method for the rapid quantification of mescaline and its metabolites in human plasma. Mescaline and its metabolites 3,4,5-trimethoxyphenylacetic acid (TMPAA), N-acetyl mescaline (NAM), and 3,5-dimethoxy-4-hydroxyphenethylamine (4-desmethyl mescaline) were simultaneously analyzed by ultra-high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). Optimal chromatographic separation was achieved with an Acquity Premier HSS T3 C18 column. The analytes were detected in positive ionization mode using scheduled multiple reaction monitoring. A single step extraction method was implemented to enable fast and automatable plasma sample preparation. An intra-assay accuracy between 84.9% and 106% and a precision of ≤ 7.33% was observed in three validation runs. Plasma was extracted by simple protein precipitation, resulting in a complete recovery (≥ 98.3%) and minor matrix effects (≤ 7.58%). No interference with endogenous matrix components could be detected in human plasma samples (n = 7). Importantly, method sensitivity sufficed for assessing pharmacokinetic parameters of mescaline in clinical study samples with lower limits of quantification of 12.5, 12.5, and 1.25 ng/mL for mescaline, TMPAA, and NAM, respectively. Nonetheless, 4-desmethyl mescaline could not be selectively quantified in pharmacokinetic samples due to interference with another mescaline metabolite. Overall, we developed and validated a reliable and very easy-to-use method for forensic applications as well as investigating the clinical pharmacokinetics of mescaline.

Detection of multi-mycotoxins in rooibos and other consumed teas in South Africa by a modified QuEChERS method and ultra-high performance liquid chromatography tandem mass spectrometry

Globally, tea is the second most consumed drink next to water as it is considered healthy with is medicinal properties. A total of 100 tea samples obtained from registered shops within South Africa were extracted using a validated QuEChERS extraction method followed by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) analysis. The suitability of the analytical method for all the analyzed mycotoxins was determined based on the recoveries (which ranged from 100 to 117%), linearity (>0.99), precision (6–29%) among other satisfactory performance characteristics. The results revealed that three of the aflatoxins i.e., AFB1, AFB2, AFG2, ochratoxin A (OTA) and zearalelone (ZEA) were not detected in all the samples analyzed, nonetheless AFG1 was detected at low concentrations (1.72–5.19 μg/kg), which were below the levels regulated in food by the EU Commission Regulation 1881/2006. The low contamination profile of mycotoxins in tea necessitates their continuous monitoring to ensure product safety. Nonetheless, since this is the first study of mycotoxin contamination of teas in South Africa, it is thus essential to conduct more studies on diverse kinds of tea for mycotoxins regulation in the country.

Rapid determination of 103 common veterinary drug residues in milk and dairy products by ultra performance liquid chromatography tandem mass spectrometry.

A multi-residue method has been developed for the identification and quantification of 103 common veterinary drug residues in milk and dairy Products. This method was based on QuEChERS with dispersive solid-phase where C18 sorbent and anhydrous sodium sulfate were used to sample purification. After evaporation and reconstitution, the samples were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The mean recovery results were all higher than 60% except ampicillin, pipemidic acid, enoxacin, and estriol, and the relative standard deviation was <20.0%. The limit of quantification ranged between 0.1 and 5 μg/kg for milk and between 0.5 and 25 μg/kg for milk powder. It was successfully used to detect residues of veterinary drug in real samples. This study proposes a simple and fast analytical method for monitoring multi-class veterinary drug residues to ensure food safety.

Zi Shen Wan Fang Attenuates Neuroinflammation and Cognitive Function Via Remodeling the Gut Microbiota in Diabetes-Induced Cognitive Impairment Mice.

Background : Cognitive dysfunction is a critical complication of diabetes mellitus, and there are still no clinically approved drugs. Zi Shen Wan Fang (ZSWF) is an optimized prescription composed of Anemarrhenae Rhizoma, Phellodendri Chinensis Cortex, and Cistanches Herba. The purpose of this study is to investigate the effect of ZSWF on DCI and explore its mechanism from the perspective of maintaining intestinal microbial homeostasis in order to find an effective prescription for treating DCI. Methods: The diabetes model was established by a high-fat diet combined with intraperitoneal injections of streptozotocin (STZ, 120 mg/kg) and the DCI model was screened by Morris water maze (MWM) after 8 weeks of continuous hyperglycemic stimulation. The DCI mice were randomly divided into the model group (DCI), the low- and high-ZSWF–dose groups (9.63 g/kg, 18.72 g/kg), the mixed antibiotic group (ABs), and the ZSWF combined with mixed antibiotic group (ZSWF + ABs). ZSWF was administered orally once a day for 8 weeks. Then, cognitive function was assessed using MWM, neuroinflammation and systemic inflammation were analyzed by enzyme-linked immunosorbent assay kits, intestinal barrier integrity was assessed by hematoxylin-eosin (HE) staining and Western blot and high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Furthermore, the alteration to intestinal flora was monitored by 16S rDNA sequencing. Results: ZSWF restored cognitive function in DCI mice and reduced levels of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α. Moreover, ZSWF protected the integrity of the intestinal barrier by increasing intestinal ZO-1 and occludin protein expression and decreasing urinary lactulose to mannitol ratio. In addition, ZSWF reshaped the imbalanced gut microbiota in DCI mice by reversing the abundance changes of a wide range of intestinal bacteria at the phyla and genus levels. In contrast, removing gut microbiota with antibiotics partially eliminated the effects of ZSWF on improving cognitive function and reducing inflammation, confirming the essential role of gut microbiota in the improvement of DCI by ZSWF. Conclusion: ZSWF can reverse cognitive impairment in DCI mice by remolding the structure of destructed gut microbiota community, which is a potential Chinese medicine prescription for DCI treatment.

Development of magnetic molecularly imprinted solid-phase extraction and ultra-high performance liquid chromatography tandem mass spectrometry for rapid and selective determination of urinary diphenyl phosphate of college students

Organophosphate esters (OPEs), known as novel alternative flame retardants, are a class of environmental endocrine disruptors. Long-term exposure to OPEs may bring a non-negligible health risk to human. Urinary OPE metabolites (mOPEs) are generally used as biomarkers to evaluate the internal exposure to OPEs. Diphenyl phosphate (DPHP), the main metabolite of aryl-OPEs, exhibited high detection rates and concentrations in urine samples. To establish a selective and simple analytical method for biomonitoring urinary DPHP, a specific magnetic molecular imprinted polymer (MMIP) was fabricated via a sol-gel method. Under optimum magnetic solid-phase extraction (MSPE) conditions, the resultant MMIP exhibited selective recognition ability, ideal adsorption capacity and good reusability on urinary DPHP enrichment. The developed MSPE method coupled with ultra-high performance liquid chromatography tandem mass spectrometry (U-HPLC-MS/MS) exhibited good precision and accuracy (spiked recoveries of 85.8%-109% with relative standard deviations (RSDs) ranged from 5.1%-13%), low detection limit of 0.035 ng/mL, and negligible matrix inhibition. Then we used this proposed method to detect urinary DPHP levels of recruited 30 college students and investigate the time variability and potential determinants. All urine samples revealed the presence of DPHP at a median concentration of 0.56 μg/g Creatinine (Cr). Moderate reproducibility of DPHP level was observed in first morning urine samples (ICC>0.40). Significant correlations were found between urinary DPHP levels and gender (β=0.72; 95% CI: 0.48∼0.96), sampling time (β=0.36; 95% CI: 0.08∼0.65) as well as the frequency for take-out food (β=0.45; 95% CI: 0.07∼0.74) (p< 0.05). Hence, a fast and sensitive MSPE-U-HPLC-MS/MS method was successfully built to quantify urinary DPHP.

The qualitative and quantitative profiling for quality assessment of Yinxing Mihuan Oral Solution and the stability study on the focused flavonol glycosides

Yinxing Mihuan Oral Solution (YMOS) has been widely applied for the treatment of coronary heart disease, angina pectoris, and cerebral ischemic disease in clinical practice. Nonetheless, the limited basic researches on quality analysis of YMOS remain a critical bottleneck that needs to be enhanced for better clinical applications. In this study, a total of 67 chemical components, including flavonoids, terpene lactones, nucleosides, etc., were tentatively characterized by ultra-high performance liquid chromatography tandem Q-Exactive Orbitrap high-resolution mass spectrometry, among which 34 compounds were further identified by comparison with reference substances. By adopting a methodologically validated method, we discovered that the quantitative estimate of multi-compounds in 22 batches of YMOS showed lot-to-lot consistency, and the additives in YMOS also met the corresponding regulations. Furthermore, five flavonol glycosides whose content presented a downward trend in the expired YMOS were focused. A systematic research on stability test focusing on the five targeted flavonol glycosides was performed under different temperatures and pH levels. It was found that ortho-diphenolic hydroxyl group on B-ring and the type of saccharide connected to 3-hydroxyl on C-ring play a pivotal role in the stability of the tested compounds. Subsequently, as the important compounds, ginkgolides A, B, and C in YMOS were simultaneously quantified with ultra performance liquid chromatography coupled with triple quadrupole mass spectrometry. In brief, this study performs a reliable chemical identification and provides a rapid and feasible method for the quality evaluation, which contributes to the in-depth investigation and safe application of YMOS for clinical uses.

Exploration of emerging environmental pollutants 6PPD and 6PPDQ in honey and fish samples

N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPDQ) can pose a threat to human health through the food chain because of their ubiquitous presence in the environment and the biotoxicity on organisms. In this work, we developed modified QuEChERS methods coupled with high performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) to explore whether 6PPD and 6PPDQ are present in fish and honey. The proposed methods showed acceptable limits of quantification (0.00043-0.001 mg/kg), linearity (R2 > 0.99), recovery (73.3%-108.3%), matrix effect (70.4%-95.6%) and repeatability (RSD < 8.4%). Accordingly, 6PPD and 6PPDQ have been discovered in snakehead, weever and Spanish mackerel fish, while none of which have been detected in the honey samples. The results of our work contributed to increasing public attention to 6PPD and 6PPDQ in agricultural products and provided important reference for the analysis of them.

Physiologically Based Pharmacokinetic Modeling of Vitamin D3 and Metabolites in Vitamin D-Insufficient Patients.

A physiologically based pharmacokinetic (PBPK) model of vitamin D3 and metabolites [25(OH)D3, 1,25(OH)2D3, and 24,25(OH)2D3] is presented. In this study, patients with 25(OH)D3 plasma concentrations below 30 ng/ml were studied after a single dose of 5000 I.U. (125 µg) cholecalciferol, provided with 5000 I.U. daily cholecalciferol supplementation until vitamin D replete [25(OH)D3 plasma concentrations above 30 ng/ml], and had serial plasma samples were collected at each phase for 14 days. Total concentrations of vitamin D3 and metabolites were measured by ultra-high performance liquid chromatography tandem mass spectrometry. A nine-compartment PBPK model was built using MATLAB to represent the triphasic study nature (insufficient, replenishing, and sufficient). The stimulatory and inhibitory effect of 1,25(OH)2D3 were incorporated by fold-changes in the primary metabolic enzymes CYP27B1 and CYP24A1, respectively. Incorporation of dynamic adipose partition coefficients for vitamin D3 and 25(OH)D3 and variable enzymatic reactions aided in model fitting. Measures of model predictions agreed well with data from metabolites, with 97%, 88%, and 98% of the data for 25(OH)D3, 24,25(OH)2D3, and 1,25(OH)2D3, respectively, within twofold of unity (fold error values between 0.5 and 2.0). Bootstrapping was performed and optimized parameters were reported with 95% confidence intervals. This PBPK model could be a useful tool for understanding the connections between vitamin D and its metabolites under a variety of clinical situations. SIGNIFICANCE STATEMENT: This study developed a physiologically based pharmacokinetic (PBPK) model of vitamin D3 and metabolites for patients moving from an insufficient to a repleted state over a period of 16 weeks.

Alpha-chloralose poisoning in cats: clinical findings in 25 confirmed and 78 suspected cases.

ObjectivesThe aim of this study was to describe the clinical picture in cats with alpha-chloralose (AC) intoxication and to confirm AC in serum from suspected cases of AC poisoning.MethodsSuspected cases of AC poisoning were identified in patient records from a small animal university hospital from January 2014 to February 2020. Clinical signs of intoxication described in respective records were compiled, the cats were graded into four intoxication severity scores and hospitalisation time and mortality were recorded. Surplus serum from select cases in late 2019 and early 2020 was analysed to detect AC with a quantitative ultra-high performance liquid chromatography tandem mass spectrometry analysis, and the AC concentration was compared with the respective cat’s intoxication severity score.ResultsSerum from 25 cats was available for analysis and AC poisoning was confirmed in all. Additionally, 78 cats with a clinical suspicion of AC intoxication were identified in the patient records, most of which presented from September to April. The most common signs of intoxication were ataxia, tremors, cranial nerve deficits and hyperaesthesia. The prevalence of clinical signs and intoxication severity differed from what has previously been reported, with our population presenting with less severe signs and no deaths due to intoxication. The majority had a hospitalisation time <48 h, irrespective of intoxication severity score.Conclusions and relevanceThis study describes the clinical signs and prognosis in feline AC intoxication. There were no mortalities in confirmed cases, indicating that AC-poisoned cats have an excellent prognosis when treated in a timely manner. Recognition of AC intoxication as a differential diagnosis for acute onset of the described neurological signs in areas where AC exposure is possible may influence clinical decision-making and help avoid excessive diagnostic procedures. A severe clinical picture upon presentation could be misinterpreted as a grave prognosis and awareness about AC poisoning may avoid unnecessary euthanasia.

Rapid quantitative analysis of 12 chemical constituents in wild-simulated and cultivated Astragali Radix based on UHPLC-MS

ObjectiveAstragali Radix (AR) is one of the most widely used traditional Chinese medicines (TCMs) for tonic, which can be divided into wild-simulated and cultivated AR according to its cultivation method. However, whether cultivated AR can replace wild-simulated AR has always been a concern. MethodsIn this study, a rapid, highly sensitive and specific analytical method using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS) was developed to quantitatively measure 12 chemical constituents of AR in the different cultivation methods. ResultsAR samples were analyzed with a good linear regression relationship (R2, 0.9983–0.9995), precisions (relative standard deviation (RSD), 1.31%−2.36%), repeatability (RSD, 2.65%−4.92%), stability (RSD, 1.50%−4.05%), and recovery (95.13%−106.52%). Through the determination of AR samples, we found the components of flavonoids in wild-simulated AR were higher than cultivated AR, the saponins in cultivated AR were higher, the ratio of saponins/flavonoids in cultivated AR was higher than wild-simulated AR. ConclusionBased on this research, it could provide guidance for the quality control of AR.

Pharmacokinetics Study of Jin-Gu-Lian Prescription and Its Core Drug Pair (Sargentodoxa cuneata (Oliv.) Rehd. et W and Alangium chinense (Lour.) Harms) by UPLC-MS/MS.

Jin-Gu-Lian (JGL) is traditionally used by Miao for the treatment of rheumatism arthralgia. At the same time, the combination of Sargentodoxa cuneata (Oliv.) Rehd. et W (SC) and Alangium chinense (Lour.) Harms (AC), the core drug pair (CDP) in the formula of JGL, is used at high frequencies in many Miao medicine prescriptions for rheumatic diseases. However, previous research lacks the pharmacokinetic study of JGL, and study on the compatibility of its CDP with other medicinal herbs in the formula is needed. This study aims to establish a simple, rapid, and sensitive Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous determination of four main bioactive components of JGL in rat plasma, including Salidroside (Sal), Anabasine (Ana), Chlorogenic Acid (CA), and Protocatechuic Acid (PCA), and compare the pharmacokinetic properties of two groups of rats after being orally administrated with JGL and its CDP extracts, respectively. The results showed that area under the plasma concentration-time curve (AUC), mean retention time (MRT), and clearance rate (CL), of Sal, Ana, CA and PCA in the two groups of rats were changed in different degrees. The CDP combined with other drugs could significantly increase the absorption of Sal and Ana, prolong its retention time in vivo, and may accelerate the absorption rate of CA and PCA. This indicated that the combination of CDP and other herbs may affect the pharmacokinetics process of active components in vivo, increase the exposure and bioavailability of compounds in the JGL group, and prolong the retention time, which may be the reason why JGL has a better inhibitory effect on inflammatory cytokines, providing a viable orientation for the compatibility investigation of herb medicines.

Distribution and Ecological Risk Assessment of Pharmaceuticals and Personal Care Products in Sediments of North Canal, China

The pollution of water bodies by pharmaceuticals and personal care products (PPCPs) has attracted widespread concern due to their widespread use and pseudo-persistence, but their effects on sediments are less known. In this study, solid-phase extraction-high performance liquid chromatography–tandem mass spectrometry (SPE-LC/MSMS) was used to investigate the occurrence and ecological risks of five typical pharmaceuticals and personal care products (PPCPs) in thirteen key reservoirs, sluices, dams, and estuaries in the Haihe River Basin. At the same time, the PPCP exchanges of surface water, groundwater, and sediments in three typical sections were studied. Finally, the PPCP’s environmental risk is evaluated through the environmental risk quotient. The results showed that the five PPCPs were tri-methoprazine (TMP), sinolamine (SMX), ibuprofen (IBU), triclosan (TCS), and caffeine (CAF). The average concentration of these PPCPs ranged from 0 to 481.19 μg/kg, with relatively high concentrations of TCS and CAF. The relationship between PPCPs in the surface sediments was analyzed to reveal correlations between SMX and TMP, CAF and IBU, CAF and TCS. The risk quotients (RQ) method was used to evaluate the ecological risk of the five detected PPCPs. The major contributors of potential environmental risks were IBU, TCS and CAF, among which all the potential environmental risks at the TCS samples were high risk. This study supplemented the research on the ecological risk of PPCPs in sediments of important reaches of the North Canal to reveal the importance of PPCP control in the North Canal and provided a scientific basis for pollution control and risk prevention of PPCPs.