[Determination of chlorate and perchlorate in infant formula by ultra-high performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for determination of perchlorate and chlorate in infant formula by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: Chlorate-~(18)O_3 and perchlorate-~(18)O_4 were added to the samples, and the filtrate was collected and analyzed by UPLC-MS/MS by vortex mixing, extraction, centrifugation and filtration. The mobile phase was 20 mmol/L ammonium formate and acetonitrile. The Waters Torus~(TM) DEA(2.1 mm×100 mm, 1.7 µm)column was used to separate chlorate and perchlorate. The negative spray ionization(ESI-) was used. The multi-response monitoring(MRM) mode was used for monitoring. The internal standard method was used for quantification. RESULTS: The linear relationships of chlorate and perchlorate were good in the range of 0.2-200 µg/L and 0.1-100 µg/L(R~2& gt; 0.999), respectively. The detection limits(LOD, S/N=3) of chlorate and perchlorate were 0.35 µg/kg and 0.12 µg/kg, respectively, and the quantitative limits(LOQ, S/N=10) of chlorate and perchlorate were 1.16 µg/kg and 0.40 µg/kg, respectively. At the addition levels of 15.0, 75.0 and 150 µg/kg, the chlorate recovery was 91.9%-102.8% and the relative standard deviation(RSD, n=6) was 2.5%-4.4%. At the addition levels of 7.5, 37.5 and 75.0 µg/kg, the recovery rate of perchlorate was 91.3%-106.3% and the RSD(n=6) was 2.6%-3.9%. CONCLUSTION The method is simple, rapid, sensitive and accurate, and is suitable for simultaneous analysis of perchlorate and chlorate in various complex substrates.

Association between body roundness index and risk of ultrasound-defined non-alcoholic fatty liver disease.

Objectives: While several indicators have been studied, the association of body roundness index (BRI) with non-alcoholic fatty liver disease (NAFLD) remains unclear. We aimed to explore the association between BRI and ultrasound-defined NAFLD. Methods: The sample dataset was extracted from the National Health and Nutrition Examination Survey (NHANES) during the period of 2017-2018. The diagnosis of NAFLD was determined based on the controlled attenuated parameter (CAP≥248 dB/m) score of liver ultrasound transient elastography (LUTE). Participants with excessive alcohol use and viral hepatitis were excluded. To delve deeper into the relationship, Multivariable logistic regression with adjustment for confounding variables and smoothing curve analysis was used to investigate the association and nonlinear relationships between BRI and NAFLD. Results: Among 4210 individuals aged 20 years or older included in the study, 28.2 % had NAFLD. Compared to the first tertile, BRI notably increased the risk of NAFLD 3.53-fold [95 % confidence interval (CI) = 2.73-4.57] in the second tertile and 7.00-fold (95%CI = 5.29-9.27) in the third tertile after adjusting for multiple covariates (P for trend <0.001). Furthermore, when BRI was treated as a continuous variable, one unit of increment in BRI was associated with 41 % higher odds of NAFLD [adjusted odds ratio (aOR) = 1.41; 95%CI = 1.34-1.48; P < 0.001]. The associations of BRI with NAFLD persisted in all subgroup analyses. A smoothing curve fitting demonstrated that the relationship between BRI and NAFLD was a nonlinear connection. The risk of NAFLD increased significantly when BRI was lower than 4.82, after which the curve showed a modest ascent. Conclusion: Higher BRI was consistently associated with an increased risk of NAFLD in US adults. BRI is a risk factor for NAFLD, and there is an imperative to give more attention to lowering the BRI.

Novel pleuromutilin derivatives as antibacterial agents: synthesis, biological evaluation and molecular docking studies.

Owing to the increasingly serious problems caused by multidrug resistance in community-acquired infection pathogens, it has become an urgent need to develop new classes of antibiotics for overcoming the resistance. In this paper, we describe the design and synthesis of novel pleuromutilin derivatives containing the (2-aminothiazol-4-yl)-4-methyl group, as well as their in vitro antibacterial activities against Gram-positive clinical bacteria. Most of the tested compounds displayed strong antibacterial activities against these methicillin-susceptible and methicillin-resistant bacteria. Particularly noteworthy compound 15 and its derivative 16e, both showed potent antibacterial properties (0.0625-0.5µg/mL) that are superior to amoxicillin and tiamulin. Molecular docking studies suggested that the amino thiazole ring on the side chains of the pleuromutilin derivatives can in general be accommodated near the mutilin core in the binding pocket, and thus play an important role in the activity of the whole molecule. The findings reported herein may provide a new insight into the design of novel pleuromutilin derivatives for human clinical use.

[Immuno-affinity chromatographic purification: the study of methods to test citrinin in monascus products by high performance liquid chromatography].

OBJECTIVE: To establish a method to test citrinin (CIT) in monascus products by immuno-affinity chromatography (IAC)-high performance liquid chromatography (HPLC), and to detect the content of CIT in monascus products in Fujian province. METHODS: IAC-HPLC was applied to detect the CIT content in monascus products. The conditions to use HPLC were as follows: C(18) reversed-phase chromatographic column, 150.0 mm×4.6mm×3 µm; mobile phase: the volume ratio of acetonitrile and 0.1% phosphoric acid solution at 65:35; isocratic elution; column temperature: 28°C; flow velocity: 0.8 ml/min; fluorescence detector, excitation wavelength (λ(ex)) was 331 nm and emission wavelength (λ(em)) was 500 nm. The standard curved was established by the linear regression of peak area (Y) to CIT content (X, ng/ml). The accuracy and precision of the method would then be verified. And 32 kinds of monascus products were determined and their color values were compared by this method. RESULT: The standard curve established in this study was Y = 4634.8X-136.42, r = 1.000; whose limits of detection was 20 µg/kg and the limits of qualification was 64 µg/kg. In the range between 200 and 800 µg/kg, the standard recovery rate was 98.9% - 110.0% (n = 3), and the relative standard deviation (RSD) was 0.51% - 1.76%. Out of the 32 samples, CIT was detected from 11 samples of monascus rice, 9 samples of monascus powder and 5 samples of monascus pigments, the content was around 0.212 - 14.500 mg/kg. 4 out of 7 functional monascus samples were detected out CIT, whose content at 0.142 - 0.275 mg/kg. CONCLUSION: The method to detect CIT in monascus products by IAC-HPLC has been established.

Ultrasound far-focused pixel-based imaging using Wiener postfilter scaled by adjustable zero-cross factor.

Synthetic aperture (SA) imaging can provide a uniform lateral resolution but an insufficient signal-to-noise ratio (SNR). SA method with bidirectional pixel-based focusing (SA-BiPBF) has the ability to obtain a higher quality image than conventional SA imaging. In this paper, an enhanced SA-BiPBF named full aperture received far-focused pixel-based (FrFPB) is firstly proposed to obtain a high resolution image. An adjustable zero-cross factor scaled Wiener postfilter (AZFsW) is then implemented in FrFPB for improving contrast ratio (CR). The adjustable zero-cross factor is calculated using the polarity of echo signals sequence with an adjustable coefficient σ to estimate the signal coherence, and it is combined with Wiener postfilter to obtain a good capability of noise reduction and background speckle pattern preservation. Simulation and experiments have been conducted to evaluate the imaging performance of the proposed methods. Results show that FrFPB can obviously improve the resolution in comparison with SA-BiPBF, and contrast-to-noise ratio (CNR) and speckle signal-to-noise ratio (sSNR) are retained. In addition, AZFsW can achieve a much higher CR than SA-BiPBF. When σ is 0.6, the CR improvement is 96.7% in simulation, 78.7% in phantom experiment, and 49.2% in in-vivo experiment. To evaluate the imaging performance of AZFsW, coherence factor, conventional Wiener postfilter, and scaled Wiener postfilter are implemented. The imaging results show that when σ is in the range of [0.6, 0.7], AZFsW exhibits a satisfying comprehensive imaging performance.

Antibiotic residues in poultry food in Fujian Province of China.

Thirty-nine kinds of antibiotics (11 quinolones, 10 tetracyclines, and 18 sulphonamides) residues were screened in 146 samples including chicken, chicken giblets, and eggs in Fujian by ultra-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) and analysed the contamination status of antibiotic residues.seventeen kinds of antibiotics were detected, with an overall detection rate of 47.3% and the exceeding rate was 11.6%. Antibiotics were found in 46.7% chicken, 72.2% chicken giblets, and 30% eggs. In 11.1% of chicken giblets and 26% of eggs, the detected concentration exceeded the maximum residue level (MRLs). The total detection rate of tetracycline antibiotics was higher than that of quinolones (33.6% vs. 24.7%) and the sulphonamides (33.6% vs. 4.8%). The exceeding rates of tetracyclines, quinolones, and sulphonamides were 2.7%, 10.3%, and 1.4%, respectively. We suggested that the abuse of antibiotics in poultry foods still exists, and more attention should be paid to the antibiotic residues in poultry eggs.

Diagnosis of liver fibrosis in patients with hepatitis B-related liver disease using ultrasound with wave-number domain attenuation coefficient.

BACKGROUND/AIMS: The importance of identifying the stage of liver fibrosis has motivated the development of non-invasive methods. This study aimed to evaluate the applicability of ultrasound analysis involving the wave-number domain attenuation coefficient (W-Ac) in the non-invasive quantitative differentiation of liver fibrosis. MATERIALS AND METHODS: This was a prospective study of inpatients with hepatitis B-related liver disease treated between October 2016 and January 2018. In ultrasound, the echo from the near-field liver tissue was selected as the reference signal. The W-Ac of liver tissues was based on the fast Fourier transform of the acquired post-beamforming radio frequency signals. These values were compared with fibrosis from biopsy METAVIR score results. A receiver operating characteristic (ROC) curve tested the W-Ac method. RESULTS: A total of 46 patients were enrolled, including 27 males and 19 females. Fibrosis was stage F0 in 12 patients, F1 in 13 patients, F2 in 10 patients, F3 in 7 patients, and F4 in 4 patients. W-Ac increased with the progression of liver fibrosis up to stage F3. There were differences between F0 and F4 stages (p<0.001) and between any 2 stages of fibrosis (p<0.05), except for stages F3 and F4. There was a significant correlation between W-Ac and METAVIR score (r=0.795, p<0.001). W-Ac differed between non-fibrosis (F0) and fibrosis (F1-F4) groups (p<0.001) and in the normal (F0), early fibrosis (F1-2), and late fibrosis groups (F3-4) (p<0.001). ROC area under the curve was 0.890, and at a cut-off of 0.12153, sensitivity was 0.706 and specificity was 0.830. CONCLUSIONS: W-Ac allowed assessment of liver fibrosis in clinical practice.

Polysaccharides from Chrysanthemum morifolium Ramat ameliorate colitis rats by modulating the intestinal microbiota community.

The gut microflora dysbiosis has been closely related with the inflammatory bowel disease (IBD). In this study, the effect of polysaccharides from Chrysanthemum morifolium Ramat on the gut microbiota was evaluated by ulcerative colitis (UC) rat model. Physiological and pathological analyses suggested that Chrysanthemum polysaccharides possessed notably protective effects on UC in vivo. Based on the Illumina MiSeq platform, 16S rRNA sequencing of the rat colonic contents indicated that the intestinal flora structure remarkably changed in the model rats and the tendency was alleviated to a certain degree by treatment with different dosages of Chrysanthemum polysaccharides. In normal groups, there were more Firmicutes than Bacteroidetes, but this change lost at the pathological state. Following Chrysanthemum polysaccharides, rising Firmicutes/Bacteroidetes ratio was validated. Besides the microbial diversity and the community richness of the UC rats were improved by Chrysanthemum polysaccharides, the composition of intestinal microflora in the model group were also restored after oral administration of Chrysanthemum polysaccharides. The abundance of opportunistic pathogens was decreased (Escherichia, Enterococcus and Prevotella), while the levels of protective bacteria such as Butyricicoccus and Clostridium (butyrate-producing bacteria), Lactobacillus and Bifidobacterium (probiotics), Lachnospiraceae and Rikenellaceae elevated in various degrees. Correlation analysis between intestinal flora and biochemical factors suggested that the relative abundance of protective bacteria was positively correlated with the levels of anti-inflammatory cytokines such as IL-4, IL-10 and IL-11, while aggressive bacteria were positively correlated with proinflammatory cytokine such as IL-23、IL-6、 IF-17、TNF-α、IL-1ß and IFN-γ. The above results showed that the intestinal flora were closely related to the secretion and expression of cytokines in the body, and they interacted with each other to regulate immune function. Thus, Chrysanthemum polysaccharides could ameliorate ulcerative colitis by fostering beneficial intestinal flora growth, modulating the balance of intestinal microecology and restoring the immune system.

Biotransformation and metabolic profile of catalpol with human intestinal microflora by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years. Catalpol, an iridoid glucoside, abundantly found in the root of the common used herb medicine Rehmannia glutinosa Libosch, has been reported to show various biological effects and pharmacological activities. After oral administration, the active ingredient might have interactions with the intestinal bacteria, which could help unravel how the medicine was processed in vivo. In this work, different pure bacteria from healthy human feces were isolated and used to bioconvert catalpol. Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technique combined with Metabolynx(™) software was applied to analyze catalpol metabolites. Compared with blank samples, parent compound (M0) and four metabolites (M1-M4) were detected and tentatively identified based on the characteristics of their protonated ions. The metabolites were likely to be: catalpol aglycone (M1), acetylated catalpol (M2), dimethylated and hydroxylated catalpol aglycone (M3), nitrogen-containing catalpol aglycone (M4). M1 and M4 were generated in the majority of the samples like Bacteroides sp. 45. M3 was obtained in several bacterial samples like Enterococcus sp. 8-2 and M2 was detected only in the sample of Enterococcus sp. 43-1. To our knowledge, the metabolic routes and metabolites of catalpol produced by human intestinal bacteria were all firstly reported.

Biotransformation of luteoloside by a newly isolated human intestinal bacterium using UHPLC-Q-TOF/MS.

To explore the metabolic pathways and metabolites of luteoloside yielded by the isolated human intestinal bacteria from healthy human feces and characterize the ß-d-glucosidase activity of the specific strain which catalyzed the breakdown of luteoloside, a preculture bacterial GAM broth and luteoloside were mixed incubated together for 48h. UHPLC-Q-TOF/MS was used for analysis of the metabolites of luteoloside in the corresponding supernatant fractions from fermentation. Aliquots of the reactive solutions were collected at different times and were measured with a microplate reader at 405nm to evaluate the enzymatic activity. Three metabolites (acetylated luteoloside, luteolin and deoxygenated luteolin) were detected in the fractions isolated from the bacterial samples. The variation of ß-d-glucosidase activity inside the bacterium was in coincidence with the changes in luteolin generation or luteoloside degradation in different time periods.