Determination of azodicarbonamide in flour samples using high-performance liquid chromatography-tandem mass spectrometry with xanthydrol pre-column derivatisation.

Azodicarbonamide (ADA) is approved as a food additive in flour products due to its oxidising and bleaching properties. However, it is prohibited in Australia and Europe on account of its toxicity and the risk of causing asthma in humans. A method was developed to determine ADA in actual flour samples. This work presents an optimised methodology based on derivatisation and clean-up procedures followed by ultra-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS/MS). The analytical method was successfully validated. An excellent result was obtained for the linearity of matrix-matched calibration curves (R2 > 0.99) in the concentration range of 0.10-80 mg/kg. The recovery rate varied from 81.7% to 102.3%. The relative standard deviations (RSDs) of repeatability (n = 6) were 1.3-4.1%, and inter-day RSDs (n = 6) were 2.2-4.8%. The limit of detection and the limit of quantification were 0.014 and 0.042 mg/kg, which were significantly lower than the requirement of 45 mg/kg stipulated in the Chinese National Food Safety Standard (GB 2760-2014). The detection rate of ADA in 26 flour samples was 23.1%, with the concentration ranging from 0.023 to 23.2 mg/kg.

Reaction of cyclamate with hypochlorous acid in vitro and formation of chlorcyclohexylamine and cyclohexylamine.

In this work, we investigated the reaction of cyclamate with hypochlorous acid (HOCl) in simulated gastric juice. The reaction products were detected by high-performance liquid chromatography diode array detection (HPLC-DAD) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). We also explored the changes in product concentration as a function of reaction time, cyclamate and HOCl concentrations. Cyclamate reacted with hypochlorous acid instantly in the simulated gastric fluid. N, N-dichlorcyclohexylamine and cyclohexylamine were both detected when the HOCl concentration was at millimole. Cyclohexylamine can only be found when HOCl concentration was at micromole. N, N-dichlorcyclohexylamine and cyclohexylamine concentrations both increased when cyclamate concentration increased under the millimole level of HOCl. As an important reactive oxygen species, hypochlorous acid (HClO) is produced in various physiological processes. The abnormal rise of the HClO level is associated with many inflammatory diseases. Chronic gastritis associated with Helicobacter pylori is a multistep, progressive, life-long inflammation. So, chronic gastritis infected with H. pylori may cause cyclamate metabolizing into cyclohexylamine in vivo.

Experimental study on pretreatment effects of [BMIM]HSO4/ethanol on the thermal behavior of cellulose.

Ionic liquids (ILs) have been investigated to dissolve and/or pre-treat cellulose by combining with a low viscous co-solvent. Dissolution and pretreatment of cellulose by ILs are dynamic processes of dissolution and precipitation, which would caused the physical and chemical changes (such as crystallinity and thermal stability) of un-dissolved cellulose residues. Hence, this study focused on the thermal behavior of un-dissolved cellulose (PCEL) after pre-treatment using [BMIM]HSO4/ethanol. Ethanol was used as a green and cheap co-solvent of 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO4) to pre-treat cellulose under different conditions. The pretreatment effect on thermal behavior of PCEL was investigated by thermogravimetric analysis and the distributed activation energy model. [BMIM]HSO4/ethanol pretreatment efficiently lowered the thermal stability of cellulose, and promoted the thermal decomposition at low temperature. The thermal behavior of PCEL can be adjusted by the [BMIM]HSO4 mass concentration.

Clinical Characteristics of H1N1 Influenza A-Associated Mild Encephalopathy with Reversible Splenial Lesion: 4 Pediatric Cases.

OBJECTIVE: Mild encephalopathy with reversible splenial lesion (MERS) is associated with a variety of infections and anti-epileptic drug withdrawal. Here we report the clinical characteristics of H1N1 influenza A-associated MERS based on our experience of four pediatric cases. METHODS: A detailed retrospective analysis of four patients with H1N1 influenza A-associated MERS was performed at Guangzhou Women and Children's Medical Center. RESULTS: All patients exhibited mild influenza-like illness and seizures. Three patients presented with a new-onset seizure with fever after 5 years of age. 75% patients had altered mental status. For all four patients, influenza A (H1N1) viral RNA was detected in throat swab specimens at least twice. Brain magnetic resonance images revealed similar ovoid lesions in the corpus callosum, mainly in the splenium and for one patient in the splenium and genu of the corpus callosum. Only one patient had an abnormal electroencephalogram tracing. Cells and protein in the cerebrospinal fluid were normal in all patients. All patients received oseltamivir and one patient received intravenous immunoglobulin. As a result, all patients fully recovered after 2 months and showed no neurologic sequelae at discharge. CONCLUSION: This case series provides insight towards clinical features of H1N1 influenza A-associated MERS.

Estimated assessment of dietary exposure to artificial sweeteners from processed food in Nanjing, China.

The objective of this study was to measure the concentrations of three intensity sweeteners (Acesulfame-K, cyclamate and saccharin) in different categories of food available on the Nanjing market, and to investigate whether the Nanjing general population was at risk for exceeding the ADI of sweeteners. A set of 1885 foods was collected and analysed using the National Food Safety Standard procedure in order to establish the concentration levels of the sweeteners. Dietary exposure was estimated using probabilistic modelling software and compared directly with each sweetener's ADI. Consumption data from the China National Nutrition and Health Survey (conducted in 2010-2013) and the actual concentrations of sweeteners in the collected food products were used to perform the intake assessment. The results indicated that Acesulfame-K and cyclamate were commonly used in processed food, and processed nuts, preserved fruit, beverages, and bakery products are the main sources of sweeteners in Nanjing. The estimated exposure of sweeteners in Nanjing was well below the ADIs, as relative intakes at the 95th percentile were 29.7% for saccharin, 79.8% for cyclamate, and 35.9% for Acesulfame-K of the respective ADIs. It was concluded that adults were not at risk of exceeding ADIs for these sweeteners, but the intake of cyclamate at the higher percentiles by children may approach or slightly exceed ADI values.

Quality of frozen porcine Longissimus lumborum muscles injected with l-arginine and l-lysine solution.

This study investigated the effects of l-arginine and l-lysine on the water holding capacity, shear force, color, and protein denaturation of frozen porcine Longissimus lumborum. Four batches were prepared, each corresponding to samples of an experimental treatment: without a cryoprotective solution, injecting a 0.3% sodium tripolyphosphate and 0.5% NaCl solution, a 0.5% l-arginine solution, or a 0.5% l-lysine solution. The results showed that both l-arginine and l-lysine decreased thawing loss, cooking loss, shear force, L⁎ values, b⁎ values, and surface hydrophobicity, but they increased pH values, a⁎ values, percentages of peak areas for T21 relaxation times, and Ca2+-ATPase activity. Additionally, both histological and transmission electron microscopy images showed that l-lysine, and especially l-arginine could inhibit the formation of gaps between fiber bundles, alleviate the disruption of intracellular spaces, and maintain the structural integrity of sarcomeres. Overall, the results showed that both l-arginine and l-lysine hindered the structural damage of muscle fibers during freezing and protected myofibrillar proteins from denaturation, ultimately contributing to superior quality attributes.

Determination of semicarbazide residue in human urine samples using liquid chromatography-tandem mass spectrometry.

An ultra-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS/MS) with pre-column derivatisation was developed and validated for the determination of semicarbazide in human urine. Urine samples were derivatised with 2-nitrobenzaldehyde and subsequently extracted with acetonitrile. Extracts were concentrated and then analysed by UPLC-MS/MS. The time per run was 7 min. Good results were observed for the linearity of matrix-matched calibration curves (R2 > 0.99) in the concentration range of 1-100 µg/L. The absolute recovery ranged from 98.7% to 108.6%, with the relative standard deviations (RSDs) of 2.2%-3.6%. The limit of detection and quantification for the semicarbazide was 0.5 µg/L and 1 µg/L, respectively. The method showed good extraction efficiency, high sensitivity, and good reproducibility. It was suitable for the detection of semicarbazide in human urine. Residues of semicarbazide were between 1.0 and 41.5 µg/L in children's 24-h urine. This work is the first report on the quantitative analysis of SEM in 24-h human urine samples.

Downregulated ribosomal protein L39 inhibits trophoblast cell migration and invasion by targeting E-cadherin in the placenta of patients with preeclampsia.

Early-onset preeclampsia (PE) is a pregnancy complication that can lead to severe adverse maternal and fetal outcomes. However, the mechanisms underlying the development of early-onset PE are not fully understood. Ribosomal protein L39 (RPL39) is a member of the S39E family of ribosomal proteins that plays an important role in stem cell self-renewal, cancer metastasis, and chemoresistance. In this study, we aimed to explore the potential function of RPL39 in placental trophoblast cells. We analyzed the expression of RPL39 in early-onset PE and normal placental tissues using real-time PCR, western blot analysis, and immunohistochemistry. The results showed that RPL39 was markedly downregulated in early-onset PE placental tissues. RPL39 knockdown inhibited trophoblast cell proliferation, migration, and invasion, as well as placental explant outgrowth. Flow cytometry analysis suggested that knockdown of RPL39 resulted in cell cycle arrest at the G0/G1 phase, but had no significant effect on cell apoptosis. We also found that RPL39 knockdown could alter cell morphology. We then measured the expression of the epithelial cell marker E-cadherin following knockdown of RPL39 in Bewo and HTR8/SVneo cells. RPL39 knockdown increased the expression of E-cadherin. Furthermore, E-cadherin expression was upregulated in placental explant outgrowth tissues transfected with RPL39 small interfering RNA. In conclusion, RPL39 plays an essential role in proliferation, invasion, and migration of trophoblast cells by targeting E-cadherin. Our findings provide novel insight into the mechanisms underlying the occurrence of early-onset PE.

Experimental study on light volatile products from thermal decomposition of lignin monomer model compounds: effect of temperature, residence time and methoxyl group.

In order to investigate the effects of temperature, residence time (RT) and methoxyl (OCH3) on the product distribution and vapor phase reactions during pyrolysis of complex solid fuels, three model phenolic representatives, phenol, guaiacol and syringol, were pyrolyzed at a residence time of 0.7 s, over a temperature range of 400 °C-950 °C, and at temperatures of 650 °C and 750 °C, in a RT region of 0.1 s-4.2 s. Increasing yields of CO and C1-C5 light hydrocarbons (LHs) with RT at 650 °C and 750 °C indicated that ring-reduction/CO elimination of phenolic compounds happened at 650 °C, and dramatically at 750 °C. The addition of OCH3 affects the product distribution and ring-reduction pathways: C5 LHs from phenol, C2 LHs, C4 LHs and C5 LHs from guaiacol, and C1-C2 LHs from syringol. CO2 yields increase with the addition of OCH3. CO2 was formed via benzoyl and a four-membered ring, which would compete with the CO formation. The addition of OCH3 promotes the formation of coke and tar. The decomposition pathways are discussed, based on the experimental data, focusing on ring-reduction reactions and the formation of CO/CO2 and C1-C5 LHs.

Generation of nine iPSC lines (HNMUi002-A, HNMUi003-A, HNMUi004-A, HNMUi005-A, HNMUi006-A, HNMUi007-A, HNMUi008-A, HNMUi009-A, HNMUi010-A) from three Chinese families with thalassemia.

Thalassemia is a group of single-gene recessive inherited hemoglobin disorders caused by a mutation or deletion of one or more globin genes, which results in abnormal globin chain synthesis and hemoglobin formation. In this study, human iPSC lines HNMUi002-A, HNMUi003-A, HNMUi004-A, HNMUi005-A, HNMUi006-A, HNMUi007-A, HNMUi008-A, HNMUi009-A, HNMUi010-A were generated from the amniotic fluid cells or urine-derived cells isolated from 9 patients with thalassemia. The iPSC lines exhibited the normal karyotype, expressed pluripotency markers, and carried α- or ß- globin gene mutations. These pluripotent stem cell lines will serve as useful tools for studying pathophysiological mechanism of thalassemia.

Histone modifications in oral squamous cell carcinoma and oral potentially malignant disorders.

Oral squamous cell carcinoma (OSCC) is a common malignancy with dismal prognosis without effective therapeutic options in advanced cases. The evolution from oral potentially malignant disorders to OSCC has poorly described underlying epigenetic features. With the ability of silencing or activation of vital genes, histone modifications' and modifiers' potentiality for early diagnosis, prognosis predicting, and therapy in OSCC were evaluated by extensive epigenetic studies. This review investigates the roles of dysregulated histone modifications and the associated modifying enzymes in OSCC onset and progression. Also, we focus on the current advances of histone modifications as therapeutic targets and the potential value of epi-drugs.

MicroRNAs in oral lichen planus and potential miRNA-mRNA pathogenesis with essential cytokines: a review.

Oral lichen planus (OLP) is a potentially premalignant condition with unknown pathogenesis. Immune and inflammatory factors are thought to play important roles in the development of OLP, and cytokines, such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, can act as critical players in the immunopathogenesis of OLP. MicroRNAs (miRNAs) are closely correlated with cytokines in various inflammation-related diseases. In patients with OLP, miRNA-146a and miRNA-155 are increased in peripheral blood mononuclear cells, and numerous miRNAs have been shown to exhibit altered expression profiles in lesions. Although the microRNA-messenger RNA (miRNA-mRNA) network is thought to be involved in the development of OLP, in-depth studies are lacking. Here, we summarize current data on the mechanisms of action of miRNAs regulating typical cytokines in OLP, including interleukin (IL)-10, IL-17, IL-22, IFN-γ, and TNF-α, to study the genetic basis of the pathogenesis of OLP and to provide prospects of therapy.

Possible alternative therapies for oral lichen planus cases refractory to steroid therapies.

Oral lichen planus (OLP) is a chronic inflammatory disorder with a multifactorial etiopathogenesis. Immune dysregulation plays a critical role in the development and progression of this disease. Patients' lives may be affected by pain caused by atrophic-erosive lesions. Given the obscure etiology, treatment is usually symptomatic. Topical steroids remain the mainstay of management. However, their therapeutic benefits are not always evident. There are substantial data on the possible therapeutic strategies that are effective in OLP cases refractory to steroids. This review provides an overview of the current approaches for the management of steroid-refractory OLP. The miscellaneous treatment regimens include tacrolimus, pimecrolimus, thalidomide, low-level laser therapy, photodynamic therapy, and surgical excision. Some results obtained from these studies were promising. However, further studies, especially randomized controlled trials with strict inclusion and exclusion criteria and larger sample sizes, are required for the evaluation of the long-term safety and efficacy of these therapies.

[Determination of four frequently-used essences in foods by ultra performance liquid chromatography-tandem mass spectrometry].

A method has been developed for the simultaneous determination of vanillin, ethyl vanillin, maltol and ethyl maltol in foods by ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). The sample was extracted with ultrapure water, and purified with SPE column. The target compounds were separated on a C18 column with the gradient elution of methanol and water containing 0.002 mol/L ammonium acetate and 0.1% (v/v) formic acid. The four components were determined in the modes of electrospray positive ionization (ESI+) and multiple reaction monitoring (MRM). The linear ranges were 10-1,000 µg/L for vanillin and maltol and 5-500 µg/L for ethyl vanillin and ethyl maltol, with the correlation coefficients more than 0.999. The recoveries of the four compounds ranged from 75.8% to 116%, with the relative standard deviations (RSDs) of 1.58%-4.01%. The method showed good extraction efficiency, high sensitivity and good reproducibility. It is suitable for the simultaneous detection of vanillin, ethyl vanillin, maltol and ethyl maltol in foods.

The role of the lactadherin in promoting intestinal DCs development in vivo and vitro.

Lactadherin, as one of the immune components in the breast milk, might play a role in the intestinal immune system of newborn. Therefore, we investigated the effect of lactadherin-feeding in early time on the development of intestinal immune system compared with naturally rearing and artificially rearing (non-lactadherin). In the present study, we observed that the Peyer's Patches (PP) from the pups of artificially reared group with lactadherin added were characterized by an excess of OX62(+)CD4(+)SIRP(+) DC cells and a higher expression of CD3(+)CD4(+)CD25(+)T cells. Additionally, this study also demonstrated that IL-10 production was dramatically increased when lactadherin was present in culture medium compared with lactadherin-absent culture. These results suggested that lactadherin could adjust intestinal DCs activity, induce CD3(+)CD4(+)CD25(+)T cell differentiation, and enhance IL-10 production.

Morphology and ontogeny of dendritic cells in rats at different development periods.

AIM: To study the morphology and ontogeny of dendritic cells of Peyer's patches in rats at different development periods. METHODS: The morphometric and flow cytometric analyses were performed to detect all the parameters of villous-crypts axis and the number of OX62(+)DC, OX62(+)CD4(+)SIRP(+)DC, and OX62(+)CD4(-)SIRP(-)DC in the small intestine in different groups of rats. The relationship between the parameters of villous-axis and the number of DC and DC subtype were analyzed. RESULTS: All morphometric parameters changed significantly with the development of pups in the different age groups (F = 10.751, 12.374, 16.527, 5.291, 3.486; P = 0.000, 0.000, 0.000, 0.001, 0.015). Villous height levels were unstable and increased from 115.24 microm to 140.43 microm as early as 3 wk postpartum. Villous area increased significantly between 5 and 7 wk postpartum, peeked up to 13817.60 microm(2) at 7 wk postpartum. Villous height and crypt depth ratios were relatively stable and increased significantly from 2.80 +/- 1.01 to 4.54 +/- 1.56, 9-11 wk postpartum. The expression of OX62(+)DC increased from 33.30% +/- 5.80% to 80% +/- 17.30%, 3-11 wk postpartum (F = 5.536, P = 0.0013). OX62(+)CD4(+)SIRP(+)DC subset levels detected in single-cell suspensions of rat total Peyer's patch dendritic cells (PP-DCs) increased significantly from 30.73% +/- 5.16% to 35.50% +/- 4.08%, 5-7 wk postpartum and from 34.20% +/- 1.35% to 43.60% +/- 2.07% 9-11 wk postpartum (F = 7.216, P = 0.005). CONCLUSION: This study confirms the age-related changes in villous-crypt axis differentiation in the small intestine. Simultaneously, there are also development and maturation in rat PP-DCs phenotypic expression. Furthermore, the morphological changes of intestinal mucosa and the development of immune cells (especially DC) peaked at 9-11 wk postpartum, indicating that the intestinal mucosae reached a relatively mature state at 11 wk postpartum.