Analysis of Glycocholic Acid in Human Plasma and Urine from Hepatocellular Carcinoma Patients

Glycocholic acid (GCA) has been identified as endogenous biomarker for hepatocellular carcinoma (HCC). To dissolve protein and liberate GCA from protein, ionic liquids (ILs) that contain chaotropic ions were used for pretreatment of liquid biological samples. Coupling with solid-phase extraction (SPE) and reversed-phase high-performance liquid chromatography (RP-HPLC), the novel sample pretreatment method was applied for quantitative determination of GCA in urine and plasma samples. Compared with the traditional organic solvents pretreatment of biological samples, the proposed method is “greener” and simpler, due to no use of volatile organic solvent, and avoiding centrifugation. Under the optimal conditions, when the GCA-free urine and plasma samples were spiked with GCA at 0.05–1.0 and 0.2–10 μmol L^?1, the recoveries of GCA ranged between 95.8–101.6 and 96.9–100.4%, respectively. These procedures only required 1 mL of urine and 3 mL of 3 mM ILs aqueous solution and 100 μL of plasma and 4 mL of 2 mM ILs aqueous solution, respectively. The proposed method has been successfully validated on a small sample size of 14 HCC patients and 14 healthy volunteers. For HCC patients, the mean concentration of GCA was 24.79 ± 6.86 and 31.98 ± 11.12 μmol L^?1 in urine and plasma samples, and was about 3 times and 24 times as much as in healthy people, respectively. The proposed method opens up a new possibility in early diagnosis of HCC.     

Speciation of Arsenic in Drinking Water by Dispersive Liquid–Liquid Microextraction,Graphite Furnace Atomic Absorption Spectrometry,and Orthogonal Array Design

Orthogonal array design was used to optimize arsenic speciation in drinking water in contact with materials by dispersive liquid–liquid microextraction followed by graphite furnace atomic absorption spectrometry. Arsenic speciation was achieved by the formation of an arsenic(III) hydrophobic complex with a new chelating agent, 1,2,6-hexanetriol trithioglycolate, at neutral pH. The complex was extracted into the organic phase, while arsenic(V) remained in aqueous solution. The concentration of As(V) was determined by subtracting As(III) from the total arsenic following the reduction of As(V) to As(III) by L-cysteine. Orthogonal array design with OA₁₆ (44) and OA₉ (33) matrices was used to optimize the efficiency of dispersive liquid–liquid microextraction and the reduction of As(V) to As(III), respectively. Under the optimal conditions, the detection limit was 0.03?µg?L^?1 for As(III) and the relative standard deviation was 5.9% with an enhancement factor of 87. The calibration curve was linear from 0.19 to 3.0?µg?L^?1 with a correlation coefficient of 0.9996. The developed method was used for arsenic speciation in solutions of drinking water that contacted materials. The recoveries of fortified samples were in an acceptable range from 92.0 to 113.3%.     

Carbon dots doped with heteroatoms for fluorescent bioimaging: a review

Carbon dots (CDs) possess superior fluorescent properties in that they do not blink, are biocompatible, chemically inert, have small size and well tunable photoluminescence (PL), can be easily functionalized with biomolecules, and can be multi-photon excited to give up-converted PL. This review (with 141 refs.) summarizes recent progress in the field of imaging using carbon dots doped with heteroatoms (X-CDs). Following an introduction, we discuss top-down and bottom-up strategies for synthesis and methods for surface modification. We also compare the differences in synthesis for undoped CDs and X-CDs. Specifically, CDs doped with heteroelemets nitrogen, phosphorus, sulfur, selenium, boron and silicium are treated. We then discuss method for determination of the properties (particle size, ZP), how doping affects fluorescence (spectra, quantum yields, decay times), and how dopants affect upconversion (UC, anti-Stokes luminescence). We finally review the progress made in fluorescent imaging of cells tissue, and other biomatter. This review also gives new hints on how to use synthetic methods for tuning the structure of X-CDs, how doping affects properties, and how to achieve new bioimaging applications.

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Graphical abstract Carbon dots doped with heteroatoms (X-CDs) are a kind of fluorescent nanomaterials that display bright fluorescence, high quantum yield, photostability, biocompatibility and low toxicity. Hence, they possess large potential for both in-vitro and in-vivo bioimaging.

     

A poly-dopamine based metal-organic framework coating of the type PDA-MIL-53(Fe) for ultrasound-assisted solid-phase microextraction of polychlorinated biphenyls prior to their determination by GC-MS

The authors describe an ultrasonic-assisted headspace method for solid phase micro-extraction (UA-HS-SPME) of 7 polychlorinated biphenyls (PCBs) with codes PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 and PCB180. The coating is based on a poly-dopamine metal-organic framework [PDA-MIL-53(Fe)] on a stainless steel wire. The coating can be prepared and evenly deposited on the stainless fiber by dipping the PDA fiber into a solution of MIL-53(Fe). The assay is also environmentally friendly because water is used as the solvent. The effects of extraction time, addition of salts, pH value and power of ultrasonic power were optimized. The coating is found to possess a high selectivity and adsorption capacity for PCBs compared to commercial SPME fibers such as the divinylbenzene/carboxen/polydimethylsiloxane fibers. Following desorption, the PCBs were quantified by GC-MS. The detection limits are between 50 and 90 pg?g^?1 of PCBs in soil. The fibers can be easily prepared, and the batch-to-batch reproducibility (RDS) is <10% (for n = 6). The fibers are inexpensive, re-usable and can be easily manipulated, and particularly well suited for screening polychlorinated biphenyls in soil.

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Graphical abstract Schematic of the preparation of an extraction fiber using stainless steel wire as substrate, PDA as adhesive, and MIL-53(Fe) as the adsorbent. It was applied to the extraction of PCBs from soil. The fiber is durable and inexpensive.

     

Naproxen Inhibits UVB‐induced Basal Cell and Squamous Cell Carcinoma Development in Ptch1+/−/SKH‐1 Hairless Mice

Naproxen possesses anti‐proliferative and pro‐apoptotic effects besides its known anti‐inflammatory functions. Here, we demonstrate the anticancer effects of naproxen against UVB‐induced basal cell carcinoma (BCCs) and squamous cell carcinoma (SCCs) in a highly susceptible murine model of UVB carcinogenesis. Naproxen significantly inhibited UVB‐induced BCCs and SCCs in this model. Tumor number and volume were significantly decreased (P < 0.005 and P < 0.05, respectively). Inhibition in UVB‐induced SCCs and BCCs was 77% and 86%, respectively, which was associated with reduced PCNA and cyclin D1 and increased apoptosis. As expected, inflammation‐related iNOS, COX‐2 and nuclear NFκBp65 were also diminished by naproxen treatment. Residual tumors excised from naproxen‐treated animal were less invasive and showed reduced expression of epithelial‐mesenchymal transition (EMT) markers N‐cadherin, Vimentin, Snail and Twist with increased expression of E‐cadherin. In BCC and SCC cells, naproxen‐induced apoptosis and activated unfolded protein response (UPR) signaling with increased expression of ATF4, p‐eIF2α and CHOP. Employing iRNA‐based approaches, we found that naproxen‐induced apoptosis was regulated by CHOP as sensitivity of these cutaneous neoplastic cells for apoptosis was significantly diminished by ablating CHOP. In summary, these data show that naproxen is a potent inhibitor of UVB‐induced skin carcinogenesis. ER stress pathway protein CHOP may play an important role in inducing apoptosis in cancer cells.     

Validation of Sun Exposure Reported Annually Against Interim Self‐report and Daily Sun Diaries

Data on personal sun exposure over a period exceeding the immediate past days or weeks are typically self‐reported in brief questionnaire items. The validity of such self‐reporting of longer term personal sun exposure, for example over a year, including detail on variation across seasons, has not previously been investigated. In a volunteer sample (n = 331) of Australian adults aged 18 years and over, we assessed the 12‐month reliability of sun exposure reported separately for each season, and its accuracy compared to a daily sun diary in the same season. Seasonal time outdoors displayed fair‐to‐good reliability between baseline and end of study (12 months), with responses showing higher agreement at lower levels of time outdoors. There was good agreement for ranking of individuals' time outdoors with the daily sun diary data, although the actual diary time outdoors was typically considerably lower than the self‐reported questionnaire data. Place of residence, education, being a smoker, day of the week (i.e. working day vs nonworking day) and working mainly outdoors were significant predictors of agreement. While participants overestimated their actual time outdoors, the self‐report questionnaire provided a valid ranking of long‐term sun exposure against others in the study that was reliable over time.     

Chemiluminescence immunoassay for cardiac troponin T by using silver nanoparticles functionalized with hemin/G-quadruplex DNAzyme on a glass chip array

The authors describe an array for chemiluminescence (CL) based determination of cardiac troponin T (cTnT), an important cardiovascular disease marker. The tracing tag consists of silver nanoparticles (AgNPs) loaded with guanine-rich DNA sequences and detection antibody in a high numerical ratio. The loaded AgNPs were then reacted with hemin to form a hemin/G-quadruplex DNAzyme. A disposable immunosensor array was fabricated by immobilizing capture antibody on corresponding sensing sites on a glass chip. Once a sandwich immunocomplex is formed on the array, the tracing tag catalyzes the CL reaction of the luminol-p-iodophenol and H₂O₂ system to produce a CL signal, which is collected by a CCD camera. An intuitive CL image is obtained containing all of the spots on the array. Under optimal conditions, the method shows a wide linear range over 4 orders of magnitude (from 0.003 to 270 ng·L^?1), a detection limit down to 84 fg·L^?1, and a throughput as high as 44 tests·h^?1. The results obtained with serum samples are in acceptable agreement with reference values. The AgNP-based tracing tag as well as the immunoassay method shows a promising potential for point-of-care testing for the early clinical diagnosis of cardiovascular disease.

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Graphical abstract Schematic presentation of silver nanoparticles (AgNPs) functionalized with hemin/G-quadruplex DNAzyme for highly sensitive chemiluminescence (CL) immunoassay of cardiac troponin T (cTnT) on a glass chip array.

     

A filter paper coated with phenylboronic acid-modified mesoporous silica for enrichment of intracellular nucleosides prior to their quantitation by HPLC

Microchimica Acta - The authors describe a filter paper modified with mesoporous silica that carries phenylboronic acid on its surface. The material possesses the advantages of the flexibility of...     

Fragilolides A-Q,norditerpenoid and briarane diterpenoids from the gorgonian coral Junceella fragilis

Chemical investigation of the gorgonian coral Junceella fragilis resulted in the isolation of a new norditerpenoid fragilolide A (1), sixteen new briarane diterpenoids fragilolides B-Q (2–17), together with frajunolides H and N, and three known norcembranoids scabrolide D, sinuleptolide and 5-epi-sinuleptolide. The structures of new compounds were determined on the basis of extensive spectroscopic analysis, including the experimental and calculated ECD data and single-crystal X-ray diffraction for the configurational assignments. The structure of fragilolide A featured an unprecedented 4,13- and 7,11-fused tetracyclic norcembranoid, while the biogenetic relationships of the briarane analogues were postulated. Frajunolide H exerted significant inhibition against a panel of tumor cell lines, and six briarane diterpenoids (3, 6, 8, 12, 16, and frajunolide N) exhibited the inhibitory effects against the HBeAg express of hepatitis B virus in HepAD38 cells. In addition, sinuleptolide and 5-epi-sinuleptolide exerted the effects to inhibit NO production in RAW264.7 macrophage cells, in addition to the activation of ARE and the inhibition of NF-κB expression.     

An isothermal strand displacement amplification strategy for nucleic acids using junction forming probes and colorimetric detection

The authors describe a method for DNA target recognition and signal amplification that is based on the target-induced formation of a three way junction. The subsequent assembly of two DNA probes releases the inhibitory strand and triggers a downstream strand displacement amplification. This causes the formation of a G-rich single sequence that binds to a hemin monomer with its peroxidase-mimicking properties. The resulting peroxidase (POx) activity is quantified by using H₂O₂ and TMB as the substrate. In the presence of an inhibitor, in contrast, the POx-like activity is strongly reduced. This forms the basis for a highly sensitive DNA assay. It has a 0.8 pM detection limit when operated at a wavelength of 450 nm and was applied to the isothermal determination of target DNA with high selectivity.

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Graphical abstract Schematic of the assay: Introduction of target results in the formation of a three way junction. The subsequent assembly of two probes releases the inhibitory strand and triggers a downstream strand displacement amplification, generating amount of G-rich single sequence which causes peroxidase-mimicking activity on binding to a hemin monomer.