On the use of a 2D-carbon microfiber fractionation system to improve flow-injection QTOF-HRMS analysis in complex matrices: the case of Abelmoschus manihot flower extracts.

A two-dimensional microscale carbon fiber/active carbon fiber system combined with a quadrupole time of flight high-resolution mass spectrometry (2DµCFs-QTOF-HRMS) system is proposed for the rapid putative identification of polar, medium-polar and weakly polar constituents in complex matrices while strongly mitigating ionic suppression effects. The capabilities of 2DµCFs-QTOF-HRMS have been proven by analysing the composition of Abelmoschus manihot flower extracts, allowing, in a single run, the detection of 41 known substances and the presence of 6 compounds never revealed before in these samples. 2DµCFs-QTOF-HRMS has been compared with traditional HPLC-MS, showing higher versatility and a significant reduction of both analysis time (70 min to 5 min) and solvent consumption (35 mL to 1.5 mL). A comparison with the results obtained by direct flow-injection MS analyses demonstrated that 2DµCFs-QTOF-HRMS leads to a more comprehensive analysis and to improved detection sensitivity. The proposed method can be considered suitable for the rapid and comprehensive analysis of food, environmental and pharmaceutical complex samples. 2DµCFs-QTOF-HRMS can thus be considered a rapid, versatile, reliable, high-throughput and economical technique that allows for the collection of information on polar, semipolar, and weakly polar components in complex matrices.

High prevalence of chronic kidney disease among patients with diabetic foot: A cross-sectional study at a tertiary hospital in China.

OBJECTIVE: Chronic kidney disease (CKD) is a severe complication of diabetes mellitus (DM). However, the prevalence of CKD among DM patients with diabetic foot (DF) is unknown. Accordingly, we conducted a cross-sectional study at a tertiary hospital to explore the prevalence of CKD among DF patients. METHODS: A total of 42 132 inpatients with DM were enrolled from May 2015 to October 2018. Four hundred and forty-seven DF patients were selected, and 116 patients with incomplete data were excluded. CKD was defined as an estimated glomerular filtration rate < 60 mL/min per 1.73 m2 or presence of proteinuria (urine protein ≥1). We compared the CKD prevalence of DF patients with non-DF patients and general CKD patients hospitalized in China. Multivariable regression analysis was performed to explore the relationship between different variables in DF patients and CKD. RESULTS: A total of 361 DF patients aged 67.9 ± 12.2 years were analyzed. Of these patients, 63.7% of were males. The prevalence of CKD was 49.0% (n = 177), which was higher than that observed for the general inpatients (4.5%, n = 871 742). However, 59.9% of CKD patients were not diagnosed during their hospitalizations. In the multivariable logistic regression analysis, after adjusting for potential confounders, the following variables were correlated with CKD: uric acid (odds ratio (OR) = 1.49, 95% confidence interval (CI) = 1.22-1.82), homocysteine (OR = 1.05, 95% CI = 1.00-1.10), and HBA1C (OR = 1.23, 95% CI = 1.04-1.47). CONCLUSION: This study revealed that the prevalence of CKD among DF patients was high, and special attention should be paid to these patients.

The spectrum of biopsy-proven secondary glomerular diseases: A cross-sectional study in China
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AIMS: The distribution of the spectrum of chronic kidney disease (CKD) has been found to vary with time. Limited information is available regarding the changing spectrum of secondary glomerular diseases (SGDs). To further investigate changes in the spectrum of SGDs, we performed a cross-sectional study. METHODS: From June 2010 to May 2015, 5,935 patients from 37 hospitals in Shandong Province were involved in this study. The study was divided into five periods according to 1-year intervals. The patients were divided into four age groups. RESULTS: Of the 5,935 patients with qualified specimens, 1,038 (17.5%) were diagnosed with a SGD. Lupus nephritis (LN) (27.6%) was the most frequently identified SGD, followed by Henoch-Schönlein purpura glomerulonephritis (HSPN) (21.7%) and diabetic nephropathy (DN) (21.6%). The prevalence rate of DN demonstrated an increasing trend, and this condition became the leading cause of renal biopsy in period 3 (29.3%). The proportion of patients with hepatitis B virus-associated nephritis (HBVAN) decreased from 14.7% in period 2 to 5.1% in period 5 (p < 0.001). The proportion of patients with amyloidosis nephropathy (AN) increased from 2.2% in period 1 to 7.0% in period 5 (p = 0.088). The prevalence rate of DN was 0.6% in pediatric patients and 40.7% in elderly patients (p < 0.001). CONCLUSIONS: In our study, SGD was the second leading cause of renal biopsy. The distribution of the spectrum of SGD varied with time and age. Given the possibility of a detection bias, larger prospective cohort studies are needed in the future.
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Arterial stiffness evaluated by carotid-femoral pulse wave velocity increases the risk of chronic kidney disease in a Chinese population-based cohort.

AIM: Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease. Although pulse wave velocity (PWV), which reflects arterial stiffness, was increased in subjects with CKD, little is known regarding whether arterial stiffness can increase the risk of CKD. To help clarify this we conducted a prospective cohort study to measure the association of arterial stiffness with CKD. METHODS: A total of 7154 adults aged 54.8 ± 10.6 years undergoing physical examinations without CKD at baseline were enrolled. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cfPWV). CKD was defined as decreased estimated glomerular filtration rate (eGFR < 60 mL/min per 1.73 m2 ) or presence of proteinuria (urine protein ≥ 1+) assessed using a repeated dipstick method. RESULTS: During 3 years of follow-up, 167 (2.3%) patients developed CKD, 101 (1.4%) patients with proteinuria and 68 (1.0%) patients with decreased eGFR. After adjusted for potential confounders, either cfPWV (per 1 m/s increase) or the highest quartile of cfPWV (increased cfPWV) was independently associated with increased risk of proteinuria, with a fully adjusted OR of 1.15 (95% CI, 1.07 to 1.23) and 1.93 (95% CI, 1.15 to 3.25), respectively. By contrast, neither cfPWV (per 1 m/s increase) nor increased cfPWV was associated with decreased eGFR in the multivariable logistic regression analysis. CONCLUSIONS: The study revealed that arterial stiffness increases the risk of proteinuria. This suggests that vascular stiffness could be considered as a target for delaying the development of CKD.

Total parathyroidectomy with autotransplantation versus subtotal parathyroidectomy for renal hyperparathyroidism: A systematic review and meta-analysis.

AIM: Total parathyroidectomy with autotransplantation (TPTX + AT) and subtotal parathyroidectomy (SPTX) have been recommended to patients with renal hyperparathyroidism (RHPT).But which one is the best surgical method remains controversial. The aim of the present study was to compare the two surgical procedures with respect to long-term outcomes. METHODS: A literature search was undertaken using Medline, EMBASE, CNKI and CBM from inception to May 2015. Study quality was assessed using the Newcastle-Ottawa Scale. Data were analyzed using Review Manager version 5.1.0. RESULTS: A total of 13 studies comprising 1589 patients with renal failure were identified. There was no statistically significant difference in the rate of symptomatic improvement (OR 0.77; 95%CI 0.22 to 2.69; P = 0.68), radiological success (OR 0.17; 95%CI 0.02 to 1.56; P = 0.90), hyperparathyroidism recurrence or persistence (OR 1.31; 95%CI 0.65 to 2.65; P = 0.45) and reoperation (OR 1.55; 95%CI 0.62 to 3.86; P = 0.35) between TPTX + AT and SPTX. The effects on serum calcium and parathyroid hormone (PTH) were similar between two surgical protocols. CONCLUSION: Both the TPTX + AT and SPTX were effective in treating RHPT and preventing recurrence. The difference between the two surgeries in recurrence or persistence and reoperation rate was insignificant. Further prospective, randomized controlled trials with high statistic power are necessary to comparative the two surgeries on the long term safety.

Increasing prevalence of membranous nephropathy in patients with primary glomerular diseases: A cross-sectional study in China.

AIM: Primary glomerular disease (PGD) remains the most common renal disease in China. A limited number of single centre studies show that the frequency of membranous nephropathy (MN) has increased; however, IgA nephropathy (IgAN) is still the most common PGD. To the best of our knowledge, there has been no multi-centre study in China that has explored the changes in PGD spectrum. To further investigate the changes in renal histopathological spectrum, we performed the cross-sectional study. METHOD: From June 2010 to May 2015, 5935 patients from 37 hospitals in Shandong Province were involved in this retrospective study. The study was divided into five periods according to 1-year intervals. The patients were divided into four age groups (≤18 years, 19-44 years, 45-59 years and ≥60 years). RESULT: Among the 5935 qualified specimens, 4855 (81.8%) were diagnosed with PGD. MN (43.3%) became the most common PGD instead of IgA (34.1%) (P < 0.001). The frequency of MN was increased from 30.7% in period 1 to 53.5% in period 5 (P < 0.001). The prevalence of MN tended to increase in every age section. IgA was the main cause of PGD in periods 1 and 2; however, its proportion decreased significantly from 41.8% in period 2 to 25.2% in period 5 (P < 0.001). CONCLUSION: Primary glomerular disease remains the most common renal disease in our study. For the first time, this cross-sectional study suggests that MN, in place of IgAN, has grown to be the first leading pathological type of PGD.

Anesthetic constituents of Zanthoxylum bungeanum Maxim.: A pharmacokinetic study.

A sensitive and selective ultra high performance liquid chromatography with tandem mass spectrometry method was established and validated for the simultaneous determination of hydroxy-α-sanshool, hydroxy-ß-sanshool, and hydroxy-γ-sanshool in rat plasma after the subcutaneous and intravenous administration of an extract of the pericarp of Zanthoxylum bungeanum Maxim. Piperine was used as the internal standard. The analytes were extracted from rat plasma by liquid-liquid extraction with ethyl acetate and separated on a Thermo Hypersil GOLD C18 column (2.1 mm × 50 mm, 1.9 µm) with a gradient elution system at a flow rate of 0.4 mL/min. The mobile phase consisted of acetonitrile/0.05% formic acid in water and the total analysis time was 4 min. Positive electrospray ionization was performed using multiple reaction monitoring mode for the analytes. The calibration curves of the three analytes were linear over the tested concentration range. The intra- and interday precision was no more than 13.6%. Extraction recovery, matrix effect, and stability were satisfactory in rat plasma. The developed and validated method was suitable for the quantification of hydroxy-α-sanshool, hydroxy-ß-sanshool, and hydroxy-γ-sanshool and successfully applied to a pharmacokinetic study of these analytes after subcutaneous and intravenous administration to rats.

Hypovolaemia was associated with clustering of major cardiovascular risk factors in general population.

BACKGROUND: Previous studies indicated that the clustering of major cardiovascular disease (CVD) risk factors is common, and multiple unhealthy lifestyles are responsible for the clustering of CVD risk factors. However, little is known about the direct association between the volume load and the clustering of CVD risk factors in general population. METHODS: We investigated the association of the clustering of CVD risk factors (defined as two or more of the following factors: hypertension, diabetes, dyslipidemia and overweight) with volume load, which was evaluated by bioelectrical impedance analysis. Hypovolaemia was defined as extracellular water/total body water (ECW/TBW) at and under the 10th percentile for the normal population. RESULTS: Among the 7900 adults, only 29.3% were free of any pre-defined CVD risk factors and 40.8% had clustering of CVD risk factors. Hypovolaemia in clustering group was statistically higher than that either in the single or in the none risk factor group, which was 23.7% vs. 17.0% and 10.0%, respectively (P <0.001). As a categorical outcome, the percentage of the lowest quartiles of ECW/TBW and TBW/TBWwatson in clustering group were statistically higher than either those in the single or in the none risk factor group, which were 44.9% vs. 36.9% and 25.1% (P <0.001), 36.2% vs. 32.2% and 25.0%, respectively (P <0.001). After adjusting of potential confounders, hypovolaemia was significantly associated with clustering of CVD risk factors, with an OR of 1.66 (95% CI, 1.45-1.90). CONCLUSIONS: Hypovolaemia was associated with clustering of major CVD risk factors, which further confirms the importance of lifestyle for the development of CVD.

Association of clustering of major cardiovascular risk factors with chronic kidney disease in the adult population.

BACKGROUND: The prevalence of chronic kidney disease (CKD) is high in China, as is the clustering of major cardiovascular (CVD) risk factors. We aimed to explore the association of clustering of CVD risk factors with CKD in the adult population. METHODS: A total of 3,287 adults who visited the Health Checkup Clinic were consecutively enrolled in the study. We investigated the clustering of four CVD risk factors (defined as two or more of the following: hypertension, diabetes, dyslipidemia, and overweight) and their association with CKD. CKD was defined as decreased estimated glomerular filtration rate (eGFR < 60 mL/min/1.73 m2) or the presence of albuminuria (urinary albumin-to-creatinine >= 30 mg/g). RESULTS: Among the total participants in this study, only 27.4% were free of any pre-defined CVD risk factors, and 46% of them had clustering of CVD risk factors. The prevalence of decreased eGFR, albuminuria, and the overall prevalence of CKD in the group of clustering of CVD risk factors was higher than in the group of none or in the group of single CVD risk factors, which were 4.9% vs. 1.0% and 1.8% (p < 0.001), 9.0% vs. 4.1% and 4.0% (p < 0.001), 12.8% vs. 5.1% and 5.8% (p < 0.001), respectively. After being adjusted for potential confounders, the clustering of CVD risk factors was positively associated with either albuminuria or CKD,with odds ratio of 1.93 (95% confidence interval [CI], 1.39 - 2.68) and 1.72 (95%CI, 1.29 - 2.28). CONCLUSIONS: Clustering of CVD risk factors was positively associated with CKD, which further confirms the importance of modifying lifestyle to reduce the burden of CKD. *contributed equally to this work.

The serum from dialysis patients with acute coronary syndrome up-regulates the expression of TLR2 and its downstream effectors in human renal glomerular endothelial cells.

BACKGROUND: This study was to investigate the expression of toll-like receptor 2 and its downstream effectors in endothelial cells in response to the serum from maintenance hemodialysis (MHD) patients with acute coronary syndrome (ACS). METHODS: Human renal glomerular endothelial cells (HRGEC) were treated in vitro with serum from the healthy subjects (control group), the MHD patients with stable angina pectoris (SAP group), or the MHD patients with ACS (ACS group). The cells in ACS group were cultured in the presence or absence of TLR2 signaling blockers for 18 h. The mRNA level for TLR2, nuclear factor-κB (NF-κB), interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (VCAM-1) were examined by real-time qPCR, the localization of TLR2 was detected by immunocytochemistry, and the secretion of IL-6 and VCAM-1 were measured by enzyme-linked immunosorbent assay. RESULTS: The mRNA level of TLR2, NF-κB and IL-6 were statistically higher in the ACS group when compared with those in SAP group and healthy controls (p < 0.05), but not significantly different between SAP and healthy controls. The secretion of IL-6 in ACS group was increased when compared with SAP group and control subjects (p < 0.05). When the HRGEC were cultured with the anti-TLR2 antibodies, the expression of NF-κB, IL-6 and VCAM-1 mRNA as well as the secretion of IL-6 and VCAM-1 were significantly inhibited (p < 0.05). CONCLUSION: This study revealed that the TLR2 signaling may mediate pro-inflammatory response in the MHD patients occurring with ACS.

Fast, sustainable, and simultaneous analysis of water- and fat-soluble vitamins by the two-dimensional microcarbon fiber fractionation system hyphenated with MS detection.

BACKGROUND: Vitamins are micronutrients that are required for normal growth and development of living organisms. However, due to their various chemical properties (e.g., acid-base behavior, the presence of numerous forms) and fluctuating concentration levels within complex matrices, simultaneous analysis of multi-class vitamins, including their active forms, is a challenging task. The growing nutrient shortage in foods is concerning for food consumers, manufacturers, and quality control organizations. Hence, a simple, fast, and greener approach that can simultaneously analyze multi-class vitamins is required to aid food testing and clinical laboratories in evaluating vitamin content more rapidly and accurately. RESULTS: A green and rapid analytical method based on online two-dimensional microscale carbon fiber/activated carbon fiber fractionation-mass spectrometry (2DµCFs-MS) was developed and validated for simultaneous determination of vitamins (water- and fat-soluble vitamins and some analogs) in food supplements and fortified energy drinks. Vitamins have been successfully separated into three different fractions using the minimum toxic solvent (only 0.7 mL of organic solvent) in a single run within 6 min. The limit of detection (LOD) ranges from 0.1 to 10.4 ng/mL, and the limit of quantification (LOQ) ranges from 0.39 to 34.5 ng/mL. The method also showed adequate repeatability and intermediate precision, with RSD<10 % and R2 > 0.99 for most vitamins. The analytical method was evaluated in terms of greenness, with an analytical greenness (AGREE) score of 0.68. SIGNIFICANCE: The 2DµCFs-MS system was developed to separate and detect multi-class vitamins simultaneously, which can be used as a beneficial tool to investigate vitamin content for food labeling and determining the vitamins in biological fluids and other complex samples. The developed method can tackle the challenge of simultaneous and fast routine analysis of multi-class vitamins.

Eco-friendly high-throughput screening of cephalosporins impurities: Utilizing 2D-carbon microfiber fractionation system combined with quadrupole time of flight high-resolution mass spectrometer.

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Specific fractionation of ginsenosides based on activated carbon fibers and online fast screening of ginseng extract by mass spectrometry.

Ginseng is beneficial in the prevention of many diseases and provides benefits for proper growth and development owing to the presence of various useful bioactive substances of diverse chemical heterogeneity (e.g., triterpenoid saponins, polysaccharides, volatile oils, and amino acids). As a result, understanding the therapeutic advantages of ginseng requires an in-depth compositional evaluation employing a simple and rapid analytical technique. In this work, three types of surface-activated carbon fibers (ACFs) were prepared by gas-phase oxidation, strong acid treatment, and Plasma treatment to obtain CO2-ACFs, acidified-ACFs, and plasma-ACFs, respectively. Three prepared ACFs were compared in terms of their physicochemical characterization (i.e., surface roughness and functional groups). A separation system was built using a column with modified ACFs, followed by mass spectrometry detection to investigate and determine substances of different polarities. Among the three columns, CO2-ACFs showed the optimum separation effect. 13 strong polar compounds (12 amino acids and1 oligosaccharide) and 15 lesser polar compounds (ginsenosides) were separated and identified successfully within 4 min in the ginseng sample. The data obtained by CO2-ACFs-TOF-MS/MS and UHPLC-TOF-MS/MS were compared. Our approach was found to be faster (4 min vs. 36 min) and greener, requiring much less solvent (1 mL vs. 10.8 mL), and power (0.06 vs. 0.6 kWh). The developed methodology can provide a faster, eco-friendly, and more reliable tool for the high-throughput screening of complex natural matrices and the simultaneous evaluation of several compounds in diverse samples.

Construction of "peptide-hemin/DNA" hybrid-complexes and their peroxidase activities.

N-Acetylated microperoxidase-11 and G-quadruplex DNA are shown to form a stable "peptide-hemin/DNA" hybrid-complex, in which the peroxidase activity at the interface between hemin and the G-quartet planes exponentially increases with increasing Ka value.

Inhibition of the expression of TGF-ß1 and CTGF in human mesangial cells by exendin-4, a glucagon-like peptide-1 receptor agonist.

BACKGROUND: Despite the presence of glucagon-like peptide-1 receptor (GLP-1R) in kidney tissues, its direct effect on diabetic nephropathy remains unclear. The transforming growth factor-ß(1) (TGF-ß(1)) and the connective tissue growth factor (CTGF) both induce extracellular matrix accumulation and persistent fibrosis in the glomerular mesangium of patients with diabetic nephropathy. OBJECTIVE: Herein, we demonstrate that a GLP-1R agonist, exendin-4, exerts renoprotective effects through its influence on TGF-ß(1) and CTGF in human mesangial cells (HMCs), cultured in a high glucose medium. METHOD: HMCs, cultured in a high glucose medium, were used for the current study. The direct effect of exendin-4 on TGF-ß(1) and CTGF expression was confirmed in HMCs. MDL-12330A (a specific adenylate cyclase inhibitor) and PKI14-22 (a protein kinase A inhibitor) were used to examine the role of the cAMP signaling pathway in exendin's anti-fibrosis action. RESULTS: The findings showed that exendin-4 inhibited the proliferation of HMCs, and upregulated the expression of TGF-ß(1) and CTGF, induced by high glucose. The effect of exendin-4 is largely dependent on the activation of adenylate cyclase. CONCLUSION: This study provides new evidence that GLP-1 acts as an antifibrotic agent in HMCs.

Oral activated charcoal suppresses hyperphosphataemia in haemodialysis patients.

AIM: Hyperphosphataemia is almost inevitable in end stage renal disease (ESRD) patients and is associated with increased morbidity and mortality. In this study we examined whether oral activated charcoal (oAC) reduces serum phosphate level in haemodialysis patients. METHODS: This was an open-label, prospective, uncontrolled study. One hundred and thirty-five haemodialysis patients were included in this study, with cessation of treatment with any phosphate binders during a 2 week washout period. Patients with serum phosphate levels greater than 5.5 mg/dL during the washout period were included for treatment with oAC. oAC was started at a dose of 600 mg three times per day with meals and was administered for 24 weeks. oAC dose was titrated up during the 24 week period to achieve phosphate control (3.5-5.5 mg/dL). A second 2 week washout period followed the end of oAC treatment. RESULTS: In the 114 patients who successfully completed the trial, the mean dose of activated charcoal was 3190 ± 806 mg/day. oAC reduced mean phosphate levels to below 5.5 mg/dL, with mean decreases of 2.60 ± 0.11 mg/dL (P < 0.01) and 103 (90.4%) of the patients reached the phosphate target. After the second washout period the phosphate levels increased to 7.50 ± 1.03 mg/dL (P < 0.01). Serum intact parathyroid hormone (iPTH) levels declined from 338.75 ± 147.77 pg/mL to 276.51 ± 127.82 pg/mL (P < 0.05) during the study. oAC had no influence on serum prealbumin, total cholesterol, triglycerides, serum ferritin, haemoglobin or platelet levels and the levels of 1,25-dihydroxyvitamin D were stable during the study. CONCLUSION: In this open-label uncontrolled study, oAC effectively controls hyperphosphataemia and hyperparathyroidism in haemodialysis patients. The safety and efficacy of oAC needs to be assessed in a randomized controlled trial.

Association between microalbuminuria and subclinical atherosclerosis evaluated by carotid artery intima-media in elderly patients with normal renal function.

BACKGROUND: Moderate to severe renal insufficiency and albuminuria have been shown to be independent risk factors for atherosclerosis. However, little is known about the direct association between subclinical atherosclerosis evaluated by carotid artery intima-media thickness (IMT) and microalbuminuria in elderly patients with normal renal function. METHODS: Subjects were 272 elderly patients (age ≥ 60 years) with normoalbuminuria (n = 238) and microalbuminuria (n = 34). Carotid IMT was measured by means of high-resolution B-mode ultrasonography. Estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m2 was defined as normal renal function. Those who had macroalbuminuria and atherosclerotic vascular disease were not included. RESULTS: Compared to subjects with normoalbuminuria, subjects with microalbuminuria had higher mean carotid IMT (1.02 ± 0.38 vs. 0.85 ± 0.28 mm; P < 0.01) and maximal IMT (1.86 ± 0.86 vs. 1.60 ± 0.73 mm; P = 0.06). By a multiple linear regression, microalbuminuria positively correlated with mean carotid IMT after adjusting for traditional cardiovascular disease risk factors including age, sex, hypertension, diabetes, smoking, total cholesterol, pulse pressure, waist circumference, serum uric acid. As a categorical outcome, the prevalence of the highest mean cariotid IMT quartile (increased IMT ≥ 1.05 mm) was compared with the lower three quartiles. After adjusted for potential confounders, microalbuminuria was associated with increased carotid IMT, with an odds ratio of 2.95 [95 % confidence interval, 1.22 - 7.10]. eGFR was not significantly associated with mean carotid IMT in our analysis. CONCLUSIONS: A slight elevation of albuminuria is a significant determinant of carotid IMT independent of traditional cardiovascular risk factors in our patients. Our study further confirms the importance of intensive examinations for the early detection of atherosclerosis when microalbuminuria is found in elderly patients, although with normal renal function.

Use of tandem carbon microfiber columns for on-line fractionation strategy of reducing ion suppression effects in electrospray ionization-mass spectrometry.

As we all know, the complexity and diversity of complex sample are confronting with challenge of high-sensitive mass spectrometry analysis, especially direct mass spectrometry. The work proposed a two-dimensional carbon microfiber fractionation (2DµCFs) system for the reduction of ion suppression effects in electrospray ionization mass spectrometry (ESI-MS). The 2DµCFs system can on-line fractionated the complex sample into strong-polar, medium-polar and weak-polar fractions for sequential MS analysis. Direct analysis brings about the strong ion suppression effect up to 85%, but the fractionated analysis of 2DµCFs system can distinctly reduce the ion suppression effect to less than 43%, even close to none. And the fractionated analysis not only decrease the number of analytes of direct analysis, but also narrows down the polarity range of analytes within the droplets of ESI, contributing to the homogeneous distribution to reduce the ion suppression effect. As an example, the 2DµCFs system coupled with tandem mass spectrometry (MS/MS) was applied for fractionated analysis of Radix Puerariae extract in 4.5 min. Compared with direct MS/MS, the 2DµCFs-MS/MS shows the lower ion suppression and the more ionic species (m/z). In addition, and most of ionic species detected by the 2DµCFs-MS/MS, are the same as those by HPLC MS/MS. Furthermore, the 2DµCFs-MS/MS exhibit the good analysis repeatability of real sample with the RSDs less than 10.32% (intra-day), 7.12% (inter-day) and 14.28% (inter-batch of CFs and ACFs). The carbon fibers (CFs) and active carbon fibers (ACFs) columns, as the key parts, are conducive to achieve on-line fractionation of compounds based on the difference of polarity. The 2DµCFs system has the merits of on-line, speediness, low-pressure and recycle. More importantly, such fast and high-throughput method is advantageous for comprehensive screening of complex samples in drug, clinical, environment and plant.

Comparative study of the immunomodulatory effects of different fucoidans from Saccharina japonica mediated by scavenger receptors on RAW 264.7 macrophages.

Scavenger receptors (SRs) have been shown to participate in regulating the immune response of macrophages, and fucoidan from Fucus vesiculosus has been verified as a ligand of class A SRs (SR-A). However, the roles of SRs in the immunomodulatory activity of fucoidan from Saccharina japonica are not clear. Thus, we performed a comparative study of the immunomodulatory activities of six different fucoidans from S. japonica on RAW 264.7 macrophages, and the roles of SRs in the processes were studied. Six fucoidans (0.5 M FPS, 1 M FPS, 2 M FPS, 0.5 M DFPS, 1 M DFPS and 2 M FPS) had different molecular weights and chemical compositions. Griess reagent system, ELISA and RT-qPCR results showed that different fucoidans displayed different stimulation of macrophages to secrete NO, IL-6, IL-1ß and TNF-α, as well as differences in the upregulation of their gene expressiones. Flow cytometric analysis of the protein expression level indicated the upregulation of TLR4 after treatment with all the fucoidans but different expressions of SRs. Furthermore, only 0.5 M DFPS and 1 M DFPS were confirmed to be ligands of SR-A through the competitive binding assay with Ac-LDL bound to the fluorescent probe DiI by flow cytometry. Our results revealed that fucoidans with low molecular weight and heterogeneity more easily bound to SRs and contributed to their immunomodulatory effects. This comparative study might promote the biological study of targeted SRs and the discovery of new pharmacological mechanisms of different fucoidans.

Nanoconfined liquid phase nanoextraction combined with in-fiber derivatization for simultaneous quantification of seventy amino-containing metabolites in plasma by LC-MS/MS: Exploration of lung cancer screening model.

Targeted metabolomics with absolute quantification is widely applied in biomarker identification and drug screening. However, due to the complexity of biological matrix and trace amount of metabolites in plasma, simultaneous quantification of highly polar metabolites in plasma with broad coverage in short time is still challenging. Herein, we proposed a nanoconfined liquid phase nanoextraction (NLPNE) combined with in-fiber derivatization (IFD) strategy that enabled simultaneous quantification of seventy amino-containing analytes in plasma, including amines, nucleosides and their metabolites. Methanol-water (2:1, v/v) was selected as nanoconfined solvent (NCS) to quickly extract highly polar analytes based on the nanoconfinement effect, followed by IFD process directly performed by adding the derivatization reagent benzoyl chloride (BzCl) within 5 min. Besides saving time, this combination strategy was environment-friendly with little organic solvent consumption and cost-effective by using reusable carbon nanofibers. Furthermore, the sensitivity was increased up to 4.92-fold compared with protein precipitation (PP) based conventional derivatization method. Key factors that affected derivatization efficiency including the derivatization time, the amount of derivatization reagent, desorption solution and CNFs, were optimized by response surface methodology (RSM). After systematical method validation, this methodology was applied to determine the multi-metabolites index in plasma of lung cancer using an integrated data processing workflow. Then lung cancer diagnosis model was established through binary logistic regression analysis to make a reference for quick lung cancer screening clinically. Taken together, the NLPNE-IFD LC-MS/MS method for targeted metabolomics enables simultaneous quantification of seventy amino-containing analytes with advantages of broad coverage, high sensitivity, time- and solvent-saving, which could be used on cancer diagnosis clinically.