Changes in Bone Mineral Density and Related Influencing Factors Assessed by Quantitative Computed Tomography in Maintenance Dialysis Patients.

OBJECTIVE: To investigate the changes in volumetric bone mineral density (vBMD) assessed by quantitative computed tomography (QCT) in chronic kidney disease (CKD) patients on maintenance dialysis. STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Radiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China, from March to July 2022. METHODOLOGY: Maintenance dialysis patients were selected for this study, and parameters related to renal function and bone metabolism markers were recorded. Patients undergoing routine physical examination were age-matched with maintenance dialysis patients to serve as the control group. vBMD scans of the lumbar spine (L1-3) were obtained by QCT for all participants. RESULTS: Among the 141 maintenance dialysis patients, there were 67 patients with secondary hyperparathyroidism (SHPT) and 74 patients with non-secondary hyperparathyroidism (non-SHPT) with mean vBMDs of 145.99±55.13 mg/cm3 and 129.10±44.20 mg/cm3, respectively. The 159 individuals in the control group had mean age of 52.77±11.66 years and mean vBMD of 129.62±36.36 mg/cm3. The vBMD of the SHPT group was greater than that of both the non-SHPT group and the control group (all p<0.05). For dialysis patients, vBMD was positively correlated with calcium-phosphorus product and intact parathyroid hormone (iPTH) levels (r = 0.181, 0.214, respectively, p<0.05); vBMD was inversely correlated with age (r = -0.555, p<0.05). After adjusting for the covariates, vBMD remained positively correlated with iPTH (r = 0.184, p<0.05). CONCLUSION: Increased lumbar vertebral vBMD in maintenance dialysis patients may be associated with high iPTH, providing clinicians with a new understanding of the changes in bone mineral density in maintenance dialysis patients. KEY WORDS: Bone mineral density, Quantitative computed tomography, Chronic kidney disease, Maintenance dialysis.

Multi-marker scans coupled to high-resolution mass spectrometry strategy for global profiling combined with structure recognition of unknown trace chlorogenic acids in Lonicera Flos.

Deep investigation, profiling of chemical diversity of constituent compounds and discovery of novel structures is a great challenge. A novel comprehensive and effective approach to mine trace unknown compounds combined with structure recognition in complex matrix is developed, in order to profiling potential Chlorogenic acids (CGAs) in Lonicera Flos (LFs): using multiple neutral loss/precursor ion (NL/PI) markers scans combined with high resolution mass spectrometry (HRMS). The workflow included (i) Fragmentation rules deduced by Q-orbitrap and selection of multiple NL/PI markers. (ii) Multiple NL/PI marker scans and grouping of peaks that had responses on two or more channels. (iii) Alignment of peaks in Full-MS scan and multiple NL/PI scans. (iv) The precursor ions list was introduced to mine novel CGAs according to simulated molecular formula. (v) Identification and structure recognition with the aid of HRMS. The procedure proved to be valid to screen and identify 51 CGAs from Lonicera Flos (LFs) with 16 categories, especially dihydroxyphenyl and glucoside for the first time. Its application could also be extended for global profiling of other complicated chemical systems, such as Chinese medicinal formulas.

Simultaneous determination of formononetin, biochanin A and their active metabolites in human breast milk, saliva and urine using salting-out assisted liquid-liquid extraction and ultra high performance liquid chromatography-electrospray ionization tandem mass spectrum.

Isoflavonoid phytoestrogens, referred as "dietary estrogens" are widely distributed in the plant kingdom. Formononetin, biochanin A and their active metabolites daidzein and genistein are known to be the most potent among other isoflavonoid phytoestrogens. Thus there is a growing need to determine accurately their concentration in different biological fluids. In the present work, a sensitive analytical method was developed for the quantitative determination of these compounds in human breast milk, saliva and urine. The glycoside conjugates of these compounds were enzymatically hydrolysis prior to salting-out assisted liquid-liquid extraction. Quantitative analysis was done by ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The obtained results showed high correlation coefficients (r2 > 0.998) for the linear range established for formononetine, biochanin A, daidzein and genistein. The limits of detection (LODs) and low limits of quantitation (LLOQs) were in the ranges of 0.05-1.0 ng/mL and 1.0-4.0 ng/mL for all analytes in human biological fluids, respectively. The average recoveries ranged from 83.29% to 115.24% for the analytes with relative standard deviation (n = 5) values from 1.84% to 9.75% in samples. Both intra-day and inter-day precisions and accuracy were found to be within 12.53% and ± 12.92% respectively. Under different conditions of stability, the concentrations for four isoflavonoid phytoestrogens deviated within ±12.87% of norminal values. The developed method was successfully validated and applied to human breast milk, saliva and urine. The average concentrations of daidzein and genistein found in breast milk, saliva and urine samples ranged from 0 to 104.2 µg/kg, 18.17 to 786.0 µg/kg, 0 to 10974 µg/kg, respectively. Their presence in breast milk samples shows exposure of breast-fed baby to isoflavones. It also allows for the rapid screening of human biological fluids when testing for formononetin, biochanin A, daidzein and genistein production status in human.

Altered brain structural and cognitive impairment in end-stage renal disease patients with secondary hyperparathyroidism.

BACKGROUND: Cognitive impairment has received attention as an important problem in patients with end-stage renal disease, although end-stage renal disease patients with secondary hyperparathyroidism have not been studied. PURPOSE: To assess the pattern of brain volume changes in end-stage renal disease patients with secondary hyperparathyroidism by using voxel-based morphometry and correlating these measures with clinical markers and the Montreal Cognitive Assessment scores. MATERIAL AND METHODS: Fifty end-stage renal disease patients with no anatomical abnormalities in conventional MRI (25 patients with secondary hyperparathyroidism, 14 men, mean age 42.20 ± 7.53 years; 25 patients without secondary hyperparathyroidism, 15 men, mean age 41.96 ± 6.17 years) were selected in this study. All patients underwent laboratory tests, neuropsychological tests, and MRI. Voxel-based morphometry analysis was performed to detect regional gray matter volume differences between the two groups. The relationships between abnormal gray matter volume and clinical markers and Montreal Cognitive Assessment scores were investigated. RESULTS: Voxel-based morphometry revealed increased gray matter volume in end-stage renal disease patients with secondary hyperparathyroidism in the bilateral caudate and bilateral thalamus compared with non- secondary hyperparathyroidism end-stage renal disease patients (P < 0.05, FWE corrected). Regarding the laboratory and neuropsychological tests, we found significant correlations between volume in these brain regions and intact parathyroid hormone levels and negative correlations with the Montreal Cognitive Assessment scores. There were no significant associations between brain volume changes and other clinical data (disease duration, urea, creatinine, and uric acid levels). CONCLUSION: Our results showed significantly increased gray matter volume in end-stage renal disease patients with secondary hyperparathyroidism, which was associated with intact parathyroid hormone levels and cognitive impairment. Serum intact parathyroid hormone levels may be a risk factor for cognitive impairment in end-stage renal disease patients with secondary hyperparathyroidism.

Simultaneous Detection of Eight Prohibited Flavor Compounds in Foodstuffs Using Gas Chromatography-Tandem Mass Spectrometry.

A multiflavor detection method, using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), has been developed for the simultaneous identification and quantification of eight prohibited flavor compounds in daily foods. Under the optimized extraction conditions, samples were purified directly through membrane filtration. Variables affecting the GC-MS/MS were optimized to obtain better separation. The excellent selectivity and sensitivity achieved in multiple reactions monitoring mode allowed satisfactory confirmation and quantitation. In this study, the linear ranges of the target compounds were 0.05 to 500 ng/L with good correlation coefficients ( R2 > 0.999). The limits of detection of target compounds ranged from 0.005 to 0.2 µg/kg. The average recoveries were in the range of 80.2 to 110.6% (beef jerky), 82.3 to 94.1% (cod liver oil), and 83.6 to 104.1% (candy).

[Screening of 17 cephalosporin residues in infant formula milk powder by ultra-high performance liquid chromatography-high resolution mass spectrometry].

A method for the simultaneous determination of 17 cephalosporinsin milk powder by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) has been developed. After dissolution in water, the homogenized milk powder samples were extracted with acetonitrile to remove impurities such as proteins and the extract was further purified by high-speed centrifugation at low temperature. A C8 chromatographic column was employed to separate the analytes. Quantitative and qualitative analyses were performed in Q Exactive Full-MS/dd-MS2 scan mode. The results revealed an excellent linear correlation over a wide range of analyte mass concentrations (5-200 µg/L) with coefficients of determination (r2) greater than 0.99 in all cases. The limits of detection (LODs) and quantitation (LOQs) were in the range of 0.0060-0.014 µg/L and 0.71-4.62 µg/kg, respectively. The overall average recoveries were 69.6%-101.4% with RSDs<10%. This method presents the advantages of simple operation, good repeatability, and high resolution, being suitable for the qualitative and quantitative screening of 17 cephalosporin residues in infant formula milk powder.

Simple, rapid, and environmentally friendly method for the separation of isoflavones using ultra-high performance supercritical fluid chromatography.

Isoflavones are natural substances that exhibit hormone-like pharmacological activities. The separation of isoflavones remains an analytical challenge because of their similar structures. We show that ultra-high performance supercritical fluid chromatography can be an appropriate tool to achieve the fast separation of 12 common dietary isoflavones. Among the five tested columns the Torus DEA column was found to be the most effective column for the separation of these isoflavones. The impact of individual parameters on the retention time and separation factor was evaluated. These parameters were optimized to develop a simple, rapid, and green method for the separation of the 12 target analytes. It only took 12.91 min using gradient elution with methanol as an organic modifier and formic acid as an additive. These isoflavones were determined with limit of quantitation ranging from 0.10 to 0.50 µg/mL, which was sufficient for reliable determination of various matrixes.

Simultaneous determination of 13 carbohydrates using high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry.

A simple, accurate, and highly sensitive method was developed for the determination of 13 carbohydrates in polysaccharide of Spirulina platensis based on high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry. Samples were extracted with deionized water using ultrasonic-assisted extraction, and the ultrasound-assisted extraction conditions were optimized by Box-Behnken design. Then the extracted polysaccharide was hydrolyzed by adding 1 mol/L trifluoroacetic acid before determination by high-performance anion-exchange chromatography coupled with pulsed amperometric detection and confirmed by high-performance anion-exchange chromatography coupled with mass spectrometry. The high-performance anion-exchange chromatography coupled with pulsed amperometric detection method was performed on a CarboPac PA20 column by gradient elution using deionized water, 0.1 mol/L sodium hydroxide solution, and 0.4 mol/L sodium acetate solution. Excellent linearity was observed in the range of 0.05-10 mg/L. The average recoveries ranged from 80.7 to 121.7%. The limits of detection and limits of quantification for 13 carbohydrates were 0.02-0.10 and 0.2-1.2  µg/kg, respectively. The developed method has been successfully applied to ambient samples, and the results indicated that high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry could provide a rapid and accurate method for the simultaneous determination of carbohydrates.

A high-throughput screening method of bisphenols, bisphenols digycidyl ethers and their derivatives in dairy products by ultra-high performance liquid chromatography-tandem mass spectrometry.

A simple and universal analytical method based on ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for high throughput screening of 21 bisphenols, bisphenols digycidyl ethers and their derivatives in dairy products was developed. Response Surface Methodology (RSM) was used to optimize sample preparation conditions based on a quick, easy, cheap, effective, rugged and safe (QuEChERS) method. The analytes were extracted by using 15 mL acetonitrile with 1% acetic acid, and the extracts were further purified by using 190 mg of C18 and 390 mg of PSA. The extracts were analyzed by UHPLC-MS/MS with electrospray ionization (ESI) source. Linearity was assessed by using matrix-matched standard calibration and good correlation coefficients (r2 > 0.99) were obtained. The limits of quantitation (LOQs) for the analytes ranged from 0.02 to 5 µg kg-1. The extraction recoveries were in a range of 88.2%-108.2%. Good method reproducibility in terms of intra- and inter-day precision was observed, yielding relative standard deviations (RSDs) less than 8.9% and 9.9%, respectively. The validation method results revealed that the proposed method was sensitive and reliable. Finally, this method was successfully applied to dairy product analysis.