Targeted changes in blood lipids improves fibrosis in renal allografts.

BACKGROUND: Chronic interstitial fibrosis is the primary barrier against the long-term survival of transplanted kidneys. Extending the lifespan of allografts is vital for ensuring the long-term health of patients undergoing kidney transplants. However, few targets and their clinical applications have been identified. Moreover, whether dyslipidemia facilitates fibrosis in renal allograft remains unclear. METHODS: Blood samples were collected from patients who underwent kidney transplantation. Correlation analyses were conducted between the Banff score and body mass index, and serum levels of triacylglycerol, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. A rat model of renal transplantation was treated with the lipid-lowering drug, fenofibrate, and kidney fibrosis levels were determined by histochemical staining. Targeted metabolomic detection was conducted in blood samples from patients who underwent kidney transplantation and were divided into fibrotic and non-fibrotic groups. Rats undergoing renal transplantation were fed either an n-3 or n-6 polyunsaturated fatty acid (PUFA)-enriched diet. Immunohistochemical and Masson's trichrome staining were used to determine the degree of fibrosis. RESULTS: Hyperlipidemia was associated with fibrosis development. Treatment with fenofibrate contributed to improve fibrosis in a rat model of renal transplantation. Moreover, n-3 PUFAs from fibrotic group showed significant downregulation compared to patients without fibrotic renal allografts, and n-3 PUFAs-enriched diet contributed to delayed fibrosis in a rat model of renal transplantation. CONCLUSIONS: This study suggests that hyperlipidemia facilitates fibrosis of renal allografts. Importantly, a new therapeutic approach was provided that may delay chronic interstitial fibrosis in transplanted kidneys by augmenting the n-3 PUFA content in the diet.

Enhancing production of hydrocarbon-rich bio-oil from biomass via catalytic fast pyrolysis coupled with advanced oxidation process pretreatment.

This study aims to propose a method for upgrading biomass pyrolysis products based on the combination of sodium persulfate pretreatment and fast catalytic pyrolysis. Combined with the analysis of components and thermogravimetric analysis, the result showed that after pretreatment the biomass structure was gradually depolymerized, the contents of lignin, the reaction of activation energy and the crystallinity of cellulose decreased. Due to the destructive effect of persulfate radicals, in fast pyrolysis, the relative contents of acids and oxygen-containing substances decreased, and the relative content of phenols can significantly increase to 19.20%. The yield of aromatic hydrocarbons and total hydrocarbons had a high value under the catalytic pyrolysis in the best performance which amount of yield reached 28.66% and 33.72%, respectively. Sodium persulfate pretreatment was beneficial in the production of hydrocarbon-rich bio-oils and high-value chemicals since the radicals can effectively depolymerize lignin which promoted the process of pyrolysis.

Fluorescence assay for three organophosphorus pesticides in agricultural products based on Magnetic-Assisted fluorescence labeling aptamer probe.

There has been increasing recent concern about the agricultural use of organophosphorus pesticides. A rapid and sensitive fluorescence assay for the detection of three organophosphorus pesticides has therefore been developed using 6-carboxy-fluorescein labeling aptamer as the probe and functionalized magnetic nanoparticles as the separation carrier. The aptamer hybridized with complementary DNA conjugated on the surface of the magnetic nanoparticles to form a magnetic aptamer-complementary DNA complex. Upon introducing the target organophosphorus pesticide, the aptamer departed from the complementary DNA, resulting in the fluorescence signal. Under optimized conditions, the limits of detection (LODs, S/N = 3) for trichlorfon, glyphosate, and malathion were 72.20 ng L-1, 88.80 ng L-1, and 195.37 ng L-1, respectively. The method was applied for the detection of trichlorfon, glyphosate, and malathion in spiked lettuce and carrot samples. The recoveries were in the range of 79.4%-118.7%, which were in good agreement with those obtained by gas chromatography, and the relative standard deviations were also acceptable. The method therefore has high sensitivity, so provides a means for the detection of multiple organophosphorus pesticides.

Tumour-specific amplitude-modulated radiofrequency electromagnetic fields induce differentiation of hepatocellular carcinoma via targeting Cav3.2 T-type voltage-gated calcium channels and Ca2+ influx.

BACKGROUND: Administration of amplitude modulated 27·12 MHz radiofrequency electromagnetic fields (AM RF EMF) by means of a spoon-shaped applicator placed on the patient's tongue is a newly approved treatment for advanced hepatocellular carcinoma (HCC). The mechanism of action of tumour-specific AM RF EMF is largely unknown. METHODS: Whole body and organ-specific human dosimetry analyses were performed. Mice carrying human HCC xenografts were exposed to AM RF EMF using a small animal AM RF EMF exposure system replicating human dosimetry and exposure time. We performed histological analysis of tumours following exposure to AM RF EMF. Using an agnostic genomic approach, we characterized the mechanism of action of AM RF EMF. FINDINGS: Intrabuccal administration results in systemic delivery of athermal AM RF EMF from head to toe at levels lower than those generated by cell phones held close to the body. Tumour shrinkage results from differentiation of HCC cells into quiescent cells with spindle morphology. AM RF EMF targeted antiproliferative effects and cancer stem cell inhibiting effects are mediated by Ca2+ influx through Cav3·2 T-type voltage-gated calcium channels (CACNA1H) resulting in increased intracellular calcium concentration within HCC cells only. INTERPRETATION: Intrabuccally-administered AM RF EMF is a systemic therapy that selectively block the growth of HCC cells. AM RF EMF pronounced inhibitory effects on cancer stem cells may explain the exceptionally long responses observed in several patients with advanced HCC. FUND: Research reported in this publication was supported by the National Cancer Institute's Cancer Centre Support Grant award number P30CA012197 issued to the Wake Forest Baptist Comprehensive Cancer Centre (BP) and by funds from the Charles L. Spurr Professorship Fund (BP). DWG is supported by R01 AA016852 and P50 AA026117.

Effect of acidic, neutral and alkaline conditions on product distribution and biocrude oil chemistry from hydrothermal liquefaction of microalgae.

Hydrothermal liquefaction (HTL) of microalgae produces high amount of water-insoluble organic compounds, the biocrude oil. Using high-growth-rate Spirulina platensis as feedstock, product fraction distribution and biocrude oil chemistry from HTL at a temperature of 240-300 °C under acidic, neutral and alkaline condition were studied. Positive effects on biocrude oil yield were only found with KOH and acetic acid, and these effects were stronger under milder HTL conditions. FT-ICR MS showed that O2 class in the biocrude was high due to higher carbohydrate in the biomass, numbers of N3O5-6 species present in the sample from acetic acid run, indicating its less decarboxylation ability. GC-MS showed more ketones and amides were formed from fatty acids in catalytic HTL, and this effect was sensitive toward reaction temperature. GPC suggested more light volatiles were in biocrude from KOH run, while analysis from NMR, FT-IR and elemental confirmed its high oil quality.

Targeting the upstream transcriptional activator of PD-L1 as an alternative strategy in melanoma therapy.

Programmed cell death ligand 1 (PD-L1) interacts with programmed cell death protein-1 (PD-1) as an immune checkpoint. Reactivating the immune response by inhibiting PD-L1 using therapeutic antibodies provides substantial clinical benefits in many, though not all, melanoma patients. However, transcriptional suppression of PD-L1 expression as an alternative therapeutic anti-melanoma strategy has not been exploited. Here we provide biochemical evidence demonstrating that ultraviolet radiation (UVR) induction of PD-L1 in skin is directly controlled by nuclear factor E2-related transcription factor 2 (NRF2). Depletion of NRF2 significantly induces tumor infiltration by both CD8+ and CD4+ T cells to suppress melanoma progression, and combining NRF2 inhibition with anti-PD-1 treatment enhanced its anti-tumor function. Our studies identify a critical and targetable PD-L1 upstream regulator and provide an alternative strategy to inhibit the PD-1/PD-L1 signaling in melanoma treatment.

Celastrol induces apoptosis in hepatocellular carcinoma cells via targeting ER-stress/UPR.

Hepatocellular carcinoma (HCC) is one of the most serious and deadly diseases worldwide with limited options for effective treatment. Biomarker-based active compound targeting therapy may shed some light on novel drugs for HCC. The endoplasmic reticulum (ER) stress and unfolded protein response (UPR) play important roles in the regulation of cell fate and have become novel signaling targets for the development of anticancer drugs. Celastrol, a triterpene from traditional Chinese medicine, has been reported to possess anti-tumor effects on various cancers. We, along with several other research groups, have recently reported that UPR was induced by celastrol in several different cancers, including hepatocellular carcinoma. However, UPR status in HCC still remains unclear. The role of ER stress and autophagy in response to celastrol also has yet to be elucidated. Our results demonstrated that celastrol could cause G2/M phase rest and inhibit proliferation in HepG2 and Bel7402. Exposure to celastrol resulted in the activation of the intrinsic apoptotic pathway, via ER stress and the UPR. In murine syngeneic model studies celastrol inhibited H22 tumor growth via the induction of ER stress and apoptosis. Our study suggests that celastrol is a potential drug for HCC therapy via targeting ER-stress/UPR.

A study on biomimetic immunoassay-capillary electrophoresis method based on molecularly imprinted polymer for determination of trace trichlorfon residue in vegetables.

Pesticide residue in vegetables is a serious problem that has adverse effects on human health. In our study, we designed and synthesized a molecularly imprinted polymer that can selectively recognize trichlorfon. Using the polymer material as biomimetic antibody, we developed a biomimetic immunoassay-capillary electrophoresis method with improved sensitivity for the detection of trichlorfon. We evaluated the competitive reactions between HRP labeled trichlorfon hapten and free trichlorfon with the biomimetic antibody. Factors that affected the sensitivity of our method were tested in detail. Under optimal conditions, the limit of detection (LOD, IC15) and the sensitivity (IC50) of this method were 0.16mgL-1 and 0.13µgL-1 for trichlorfon. We used this method to determine the trichlorfon spiked in the kidney bean and cucumber samples with recoveries ranging from 78.8% to 103%. We also detected residual trichlorfons in the leek samples, and these results were verified by gas chromatography method.

Enhanced biotic and abiotic transformation of Cr(vi) by quinone-reducing bacteria/dissolved organic matter/Fe(iii) in anaerobic environment.

This study investigated the simultaneous transformation of Cr(vi) via a closely coupled biotic and abiotic pathway in an anaerobic system of quinone-reducing bacteria/dissolved organic matters (DOM)/Fe(iii). Batch studies were conducted with quinone-reducing bacteria to assess the influences of sodium formate (NaFc), electron shuttling compounds (DOM) and the Fe(iii) on Cr(vi) reduction rates as these chemical species are likely to be present in the environment during in situ bioremediation. Results indicated that the concentration of sodium formate and anthraquinone-2-sodium sulfonate (AQS) had apparently an effect on Cr(vi) reduction. The fastest decrease in rate for incubation supplemented with 5 mM sodium formate and 0.8 mM AQS showed that Fe(iii)/DOM significantly promoted the reduction of Cr(vi). Presumably due to the presence of more easily utilizable sodium formate, DOM and Fe(iii) have indirect Cr(vi) reduction capability. The coexisting cycles of Fe(ii)/Fe(iii) and DOM(ox)/DOM(red) exhibited a higher redox function than the individual cycle, and their abiotic coupling action can significantly enhance Cr(vi) reduction by quinone-reducing bacteria.

Effect of garlic powder on acrylamide formation in a low-moisture model system and bread baking.

BACKGROUND: Acrylamide (AA) is of concern worldwide because of its neurotoxicity, genotoxicity and reproductive/developmental toxicity. Consequently, methods for minimizing AA formation during food processing are vital. RESULTS: In this study, the formation and elimination of AA in an asparagine/glucose low-moisture model system were investigated by response surface methodology. The effect of garlic powder on the kinetics of AA formation/elimination was also evaluated. The AA content reached a maximum level (674.0 nmol) with 1.2 mmol of glucose and 1.2 mmol of asparagine after heating at 200 °C for 6 min. The AA content was greatly reduced with the addition of garlic powder. Compared to without garlic powder, an AA reduction rate of 43% was obtained with addition of garlic powder at a mass fraction of 0.05 g. Garlic powder inhibited AA formation during the generation-predominant kinetic stage and had no effect on the degradation-predominant kinetic stage. The effect of garlic powder on AA formation in bread and bread quality was also investigated. Adding a garlic powder mass fraction of 15 g to 500 g of dough significantly (P < 0.05) reduced the formation of AA (reduction rate of 46%) and had no obvious effect on the sensory qualities of the bread. CONCLUSION: This study provides a possible method for reducing the AA content in bread and other heat-treated starch-rich foods.

Study on a biomimetic enzyme-linked immunosorbent assay method for rapid determination of trace acrylamide in French fries and cracker samples.

BACKGROUND: Acrylamide has attracted worldwide concern due to its neurotoxicity, genotoxicity, reproductive-development toxicity. It is necessary to develop an accurate and reliable analytical method to prevent the harm on the human health. RESULTS: In this study, a sensitive and fast analytical method of direct competitive biomimetic enzyme-linked immunosorbent assay (BELISA) was developed using a hydrophilic imprinted membrane as biomimetic antibody. This novel imprinted membrane was directly synthesised on the well surface of MaxiSorp polystyrene 96-well plates in an aqueous environment, and it exhibited high binding ability and specificity toward acrylamide. Under the optimal conditions, the established BELISA method had a good sensitivity (IC50, 8.0 ± 0.4 mg L(-1)) and a low limit of detection (IC15, 85.0 ± 4.2 µg L(-1)). The blank potato samples spiked with acrylamide at three levels of 100, 250 and 500 µg L(-1) were extracted and determinate by the proposed method, and good recoveries ranging from 90.0% to 110.5% were obtained. This presented method was applied to the quantitative detection of the acrylamide in French fries and cracker samples. Also, the results were correlated well with that obtained by the gas chromatography method. CONCLUSION: With good properties of high sensitivity, simple pre-treatment and low cost, this BELISA could be a promising screening method in food sample analysis.

Study of a molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography for simultaneous determination of trace trichlorfon and monocrotophos residues in vegetables.

BACKGROUND: Organophosphate pesticide residues are harmful to human health because of their potential mutagenic and carcinogenic properties. Therefore, it is of great importance to development an accurate and reliable analytical method to prevent their uncontrolled effects on environmental pollution and human health. RESULTS: This study reports a new method of molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography (MISPE-HPLC) for simultaneous determination of two organophosphate pesticides residues. Two types of molecularly imprinted polymers (MIPs) were prepared using the trichlorfon and monocrotophos as the template molecule, respectively, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. The recognition ability and adsorption-desorption dynamic of each imprinted polymer toward the trichlorfon or monocrotophos were characterised. Using the mixture of trichlorfon-MIP and monocrotophos-MIP (20:80, wt/wt) as solid-phase extraction sorbent, the factors affecting the pre-concentration on the analytes and the sensitivity of the MISPE-HPLC method were optimised. Under optimal condition, the linear range was 0.005-1.0 mg L⁻¹. The limit of detection was 4.2 µg g⁻¹ for trichlorfon, and 1.2 ng g⁻¹ for monocrotophos. The peak area precision [Relative standard deviation (RSD)] for three replicates was 2.9-4.5%. The blank rape and cauliflower samples spiked with trichlorfon and monocrotophos at 0.05 and 0.005 µg g⁻¹ levels were extracted and determined by this method with recoveries ranging from 88.5% to 94.2%. Moreover, this method was successfully applied to the quantitative detection of the trichlorfon and monocrotophos residues in leek samples. CONCLUSION: With good properties of high sensitivity, simple pre-treatment and low cost, this MISPE-HPLC method could provide a new tool for the rapid determination of multi-pesticide residues in the complicated food samples.

Preparation and application of immobilised ionic liquid in solid-phase extraction for determination of trace acrylamide in food samples coupled with high-performance liquid chromatography.

BACKGROUND: Acrylamide has attracted worldwide concerns because of its demonstrated neurotoxicity, genetoxicity and reproductive-development toxicity. It is necessary to control acrylamide production during food processing and protect human health. RESULTS: In this study, a functionalised material was synthesised by immobilising an ionic liquid onto an activated silica gel surface. The adsorption ability of the material towards acrylamide was evaluated, and the results showed that it had high adsorption capacity. Scatchard analysis indicated that the binding sites in the prepared material had two distinct groups (high and low affinity binding sites). The saturated adsorption capacity (Q(max,1)) was 7.9 mg g(-1) due to the high affinity binding sites, and another saturated adsorption capacity (Q(max,2)) was 2.3 mg g(-1) due to the low affinity binding sites. This prepared material also offered fast kinetics for adsorption of the acrylamide. Using this material as sorbent, a method of solid-phase extraction coupled with high-performance liquid chromatography (SPE-HPLC) for analysis of acrylamide in foods was developed. Under optimal conditions, the limit of detection (S/N = 3) of this method for acrylamide was 2.1 µg kg(-1), and the RSD for five replicate extractions of 50 µL(-1) acrylamide was 4.5%. The blank potato and bread crumb samples spiked with acrylamide at different levels of 10.0 and 15.0 µg kg(-1) were extracted and determined respectively by this developed method, and recoveries ranging from 83.0% to 89.1% were obtained. Finally, this method was applied to quantitative detection of acrylamide in bread crust and cracker samples. CONCLUSION: With high sensitivity and pre-treatment simplicity, this SPE-HPLC method could provide a new tool for the rapid determination of acrylamide in the food samples.

Effect of porphobilinogen on the formation of garlic green pigments.

BACKGROUND: Garlic (Allium sativum L.) bulb is processed into various forms such as crushed garlic, garlic juice, granules, dehydrated garlic pieces and garlic powder. However, greening is often a major problem when garlic is crushed, since it affects the appearance and quality of the resulting product. Therefore study of the formation mechanism of garlic green pigments is very important for garlic processing. RESULTS: The effect of porphobilinogen (PBG) on the formation of garlic green pigments was investigated in this study. As the storage time increased, there was a significant positive correlation between garlic greening and PBG content at low temperature (4 °C). PBG content decreased significantly during the garlic greening process. When treated with respiration inhibitor, both garlic greening strength and PBG content decreased as the concentration of respiration inhibitor increased. The green colour was generated when extracted PBG and allicin mixed thoroughly. CONCLUSION: There was a clear relationship between PBG content and garlic greening. As a provider of pyrrolyl compounds, PBG plays an important role in the formation of garlic green pigments.