miR-155 promotes cutaneous wound healing through enhanced keratinocytes migration by MMP-2

Abstract

Inflammation, re-epithelization and tissue remodeling are three essential steps during wound healing. The re-epithelization process plays the most important role which mainly involves keratinocyte proliferation and migration. miR-155 has been reported to participate in cell migration and transformation, however, its function in skin wound healing is largely unknown. Here we hypothesize that overexpression of miR-155 at wound edges could accelerate wound healing mediated by enhanced keratinocyte migration. To test this hypothesis, direct local injection of miR-155 expression plasmid to wound edges was conducted to overexpress miR-155 in vivo. Results shown that miR-155 significantly promoted wound healing and re-epithelization compared to control, while did not affect wound contraction. Also, miR-155 overexpression accelerated primarily cultured keratinocyte migration in vitro, but had no effect on cell proliferation. Importantly, western blot analysis shown that MMP-2 was significantly upregulated whiles its inhibitor TIMP-1 downregulated after miR-155 treatment. Moreover, the use of ARP-101, an MMP-2 inhibitor, effectively attenuated the accelerative effects on cell migration induced by miR-155. Taken together, our results suggest that miR-155 has the promote effect on wound healing that is probably mediated by accelerating keratinocyte migration via upregulated MMP-2 level. This study provides a rationale for the therapeutic effect of miR-155 on wound healing.

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HPV and Oral Squamous Cell Carcinoma: A Review of HPV-positive OSCC and Possible Strategies for Future

Publication date: Available online 1 March 2017
Source:Current Problems in Cancer
Author(s): Shan Jiang, Yong Dong
BackgroundOral Squamous Cell Carcinoma (OSCC) is a common cancer worldwide. Besides tobacco use and alcohol consumption, Human Papillomavirus (HPV) infection has also been identified as a risk factor for OSCC recently. The OSCC incidence has increased in recent years, especially among younger women. The purpose of this paper is to review clinical and epidemiological studies on the association between HPV infection and OSCCs, and the efficacy of HPV vaccine, so as to provide possible policy implications for preventing HPV-positive OSCC.Methodit is necessary to review the present related body of knowledge to determine whether the association between HPV infection and OSCC has been thoroughly studied. The study was based on literature review. Studies were identified using electronic databases including MEDLINE, PubMed, EMBASE, etc. The inclusion and exclusion criteria were on the basis of consultation from a panel of experts in this area and carefully designed.Resultsbased on a systematic review of literatures, HPV infection is a possible cause for the incidence of HPV-positive OSCCs. The prevalence of HPV infection possibly contributed to the increasing trends of HPV-positive OSCCs. Oral HPV infection is a form of HPV transmission. Oral sex behaviors and open-mouthed kissing are probably reasons for oral HPV infection. We also have some epidemiological evidences proving that HPV vaccine provides a possible solution for preventing oral HPV infection.ConclusionsIncreased awareness of HPV-positive OSCCs is essential due to the severity of this problem. Biological and epidemiological data regarding the link between sexual behavior and HPV-associated cancers indicates a probable connection, although definitive data is needed. Future studies are needed to investigate the mechanisms of how HPV infection causes HPV-positive OSCCs, whether HPV vaccine provides a prevention for OSCCs, and other important issues.



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Surgical management of urinary stones with abnormal kidney anatomy

Publication date: Available online 1 March 2017
Source:The Kaohsiung Journal of Medical Sciences
Author(s): Giray Ergin, Mustafa Kirac, Ali Unsal, Burak Kopru, Mustafa Yordam, Hasan Biri
In spite of the fact that urologic surgical techniques used by urologists are becoming more and more minimally invasive and easier because of developing technologies, surgical approaches for the urinary stones in kidneys with abnormal anatomy are still confusing. The objective of this article is to determine the treatment options in these kidneys. For this purpose, between 2005 and 2015, we retrospectively evaluated patients operated for urolithiasis with various congenital renal anomalies in five referral urology clinics in our country. Of the 178 patients (110 male, 60 female), 96 had horseshoe kidneys, 42 had pelvic ectopic kidneys (PEKs), and 40 had isolated rotation anomalies (IRAs) of the kidney. We evaluated the patients for stone-free rate (SFR), mean operation time, mean hospitalization time, and complication rate. In horseshoe kidney, SFRs for retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups were 72.2% and 90%, respectively. In PEKs, these rates were 83.6% and 100% for RIRS and laparoscopic pyelolithotomy, respectively. SFRs in kidneys with IRA were 75% for RIRS and 83.3% for PNL. The mean operation time for RIRS and PNL groups in horseshoe kidney was 40.5±11.2 minutes and 74.5±19.3 minutes, respectively. In PEKs, these times were 52.1±19.3 minutes and 53.1±24.3 minutes for RIRS and laparoscopic pyelolithotomy, respectively. Mean operation time in kidneys with IRA was 48.7±14.4 minutes for RIRS and 53.2±11.3 minutes for PNL. Mean hospitalization times for RIRS and PNL groups in horseshoe kidneys were 1.4±0.7 days and 2.2±1.4 days, respectively. In PEKs, these times were 2.7±1.8 days and 1.9±0.4 days for RIRS and laparoscopic pyelolithotomy, respectively. Mean operation time in kidneys with IRA was 1.5±0.9 days for RIRS and 1.8±0.6 days for PNL. The results of our study showed that RIRS could be used in all of types of abnormal kidneys with small- and medium-sized renal calculi safely and satisfactorily.



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Incidence trends in oesophageal cancer by histological type: An updated analysis in Sweden

Publication date: April 2017
Source:Cancer Epidemiology, Volume 47
Author(s): Shao-Hua Xie, Fredrik Mattsson, Jesper Lagergren
BackgroundWe aimed to update incidence trends of oesophageal cancer by histological type in Sweden.MethodsUsing data from the Swedish Cancer Registry, we examined incidence trends of oesophageal cancer by histological types in individuals aged ≥50 years in 1970–2014 using log-linear joinpoint regressions.ResultsThe age-standardised incidence rate of oesophageal adenocarcinoma in men increased on average by 3.0% per year in 1970–1994, followed by a more rapid increase of 13.7% per year in 1994–2000, and a slower increase of 2.6% per year in 2010–2014. The rate of oesophageal adenocarcinoma in women increased on average by 4.2% per year during the entire period. The rate of squamous cell carcinoma generally decreased over the past 2–3 decades in both sexes.ConclusionsThe incidence of oesophageal adenocarcinoma continues to rise in Sweden, although the increase seems to have slowed down in men since 2000. The incidence of oesophageal squamous cell carcinoma is decreasing.



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Extent and computed tomography appearance of early radiation induced lung injury for non-small cell lung cancer

Publication date: Available online 1 March 2017
Source:Radiotherapy and Oncology
Author(s): Uffe Bernchou, Rasmus Lübeck Christiansen, Jon Thor Asmussen, Tine Schytte, Olfred Hansen, Carsten Brink
Background and purposeThe present study investigates the extent and appearance of radiologic injury in the lung after radiotherapy for non-small cell lung cancer (NSCLC) patients and correlates radiologic response with clinical and dosimetric factors.Methods and materialsEligible follow-up CT scans acquired up to six months after radiotherapy were evaluated for radiologic injuries in 220 NSCLC patients. Radiologic injuries were divided into three categories: (1) interstitial changes, (2) ground-glass opacity, or (3) consolidation. The relationship between the fraction of injured lung of each category and clinical or dosimetric factors was investigated.ResultsRadiological injuries of category 1–3 were found in 67%, 52%, and 51% of the patients, and the mean (and maximum) fraction of injured lung was 4.4% (85.9%), 2.4% (46.0%), and 2.1% (22.9%), respectively. Traditional lung dose metrics and time to follow-up predicted lung injury of all categories. Older age increased the risk of interstitial changes and current smoking reduced the risk of consolidation in the lung.ConclusionRadiologic injuries were frequently found in follow-up CT scans after radiotherapy for NSCLC patients. The risk of a radiologic response increased with increasing time and lung dose metrics, and depended on patient age and smoking status.



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Alopécie frontale fibrosante : étude prospective de 20 cas

Publication date: Available online 1 March 2017
Source:Annales de Dermatologie et de Vénéréologie
Author(s): S. Elloudi, S. Gallouj, M. Meziane, F.-Z. Mernissi, M. Rimani
IntroductionL'alopécie frontale fibrosante (AFF) est une variante de lichen plan pilaire touchant volontiers la femme ménopausée. Nous rapportons une série de vingt observations d'AFF et en décrivons les caractéristiques épidémiologiques, cliniques, dermatoscopiques et évolutives sous traitement.Patients et méthodesIl s'agit d'une étude prospective qui a inclus, sur une durée de 16 mois, tous les malades atteints d'AFF ayant consulté au service de dermatologie du CHU Hassan II de Fès.RésultatsTous les patients étaient de sexe féminin ; leur âge moyen était de 46 ans et 65 % d'entre elles n'étaient pas ménopausées. L'examen dermatoscopique objectivait des signes spécifiques de la maladie. La biopsie cutanée, orientée par la dermatoscopie, confirmait dans tous les cas le diagnostic de lichen plan pilaire dans sa variante AFF. Des affections dysimmunitaires et autres étaient notées chez la moitié des patientes. Des traitements variés étaient instaurés : dermocorticoïdes, tacrolimus en pommade, minoxidil topique à 2 %, hydroxychloroquine, finastéride oral…ConclusionL'AFF est de plus en plus décrite chez des femmes avant la ménopause. La dermatoscopie facilite le diagnostic, oriente la biopsie, évalue l'efficacité du traitement et estime le pronostic.BackgroundFrontal fibrosing alopecia (FFA) is a variant of lichen planopilaris predominantly affecting postmenopausal women. We report a series of 20 cases of FFA and describe the epidemiological, clinical, dermoscopic features and progress under treatment.Patients and methodsThis was a prospective study conducted over a period of 16 months in patients seen at the dermatology department of the Hassan II University in Fez, Morocco.ResultsMean patient age was 46 years. Patients were premenopausal in 65% of cases. Dermoscopic examination revealed specific signs of the disease. Skin biopsy guided by dermoscopy confirmed the diagnosis of lichen planus pilaris in its FFA variant in all cases. Immune dysfunctions and other disorders were noted in half of the cases. Various treatments had been initiated, including topical corticosteroids, tacrolimus ointment, minoxidil 2%, hydroxychloroquine, and oral finasteride. The results were satisfactory with a decline within one year.ConclusionFFA is increasingly widely described in premenopausal women. Dermoscopy may be used to facilitate diagnosis, guide biopsy, evaluate treatment efficacy and establish a prognosis.



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Editorial Board

Publication date: March 2017
Source:Journal of Autoimmunity, Volume 78





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226Ra dynamic lixiviation from phosphogypsum samples by an automatic flow-through system with integrated renewable solid-phase extraction

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Melisa Rodas Ceballos, Antoni Borràs, Rafael García-Tenorio, Rogelio Rodríguez, José Manuel Estela, Víctor Cerdà, Laura Ferrer
The release of ²²⁶Ra from phosphogypsum (PG) was evaluated by developing a novel tool for fully automated ²²⁶Ra lixiviation from PG integrating extraction/pre-concentration using a renewable sorbent format. Eight leached fractions (30mL each one) and a residual fraction were analyzed allowing the evaluation of dynamic lixiviation of ²²⁶Ra. An automatic system allows this approach coupling a homemade cell with a ²²⁶Ra extraction/pre-concentration method, which is carried out combining two procedures: Ra adsorption on MnO2 and its posterior co-precipitation with BaSO4. Detection was carried out with a low-background proportional counter, obtaining a minimum detectable activity of 7Bqkg⁻¹. Method was validated by analysis of a PG reference material (MatControl CSN-CIEMAT 2008), comparing the content found in fractions (sum of leached fractions + residual fraction) to the reference value. PG samples from Huelva (Spain) were studied. ²²⁶Ra average activity concentration of the sum of leached fractions with artificial rainwater at pH 5.4±0.2 was 105±3Bqkg⁻¹d.w. representing a ²²⁶Ra lixiviation of 37%; while at pH 2.0±0.2, it was 168±3Bqkg⁻¹ d.w., which represents a 50%. Also, static lixiviation, maintaining the same experimental conditions, was carried out indicating that, for both considered pH, the ²²⁶Ra release from PG is up to 50% higher in a dynamic leaching that in a static one, may have both environmental and reutilization implications.

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Development, validation and comparison of near infrared and Raman spectroscopic methods for fast characterization of tablets with amlodipine and valsartan

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Tibor Casian, Andra Reznek, Andreea Loredana Vonica-Gligor, Jeroen Van Renterghem, Thomas De Beer, Ioan Tomuță
The objective of this study was to develop, validate and compare NIR and Raman spectroscopic methods for fast characterization in terms of API content and tensile strength of fixed-dose combination tablets containing amlodipine and valsartan.For the APIs assay NIR-transmittance and Raman-reflectance methods were considered, whereas for the tensile strength assay Raman spectra were recorded in reflectance configuration and NIR spectra were recorded in both reflectance and transmittance. Multivariate calibration models (PLS) were built by applying different pre-processing methods (SNV, MSC, SD+SNV) on certain spectral regions. Correlating pre-processed spectral data with tablet properties resulted in highly predictive models except in the case of NIR-transmittance spectra for tensile strength estimation. The best models selected by cross-validation were further validated on independent samples in terms of linearity, trueness, accuracy and precision. Using Bland and Altman analysis the analytical performance of the NIR and Raman methods were compared, demonstrating their similarity considering the investigated applications. The two spectroscopic methods can be used in association to confirm each others results for at-line characterization of the pharmaceutical product.

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Migration test of Bisphenol A from polycarbonate cups using excitation-emission fluorescence data with parallel factor analysis

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): M.L. Spagnuolo, F. Marini, L.A. Sarabia, M.C. Ortiz
Bisphenol A (BPA) is one of the most largely produced chemical in the world; it is used to make plastics and epoxy resins. The endocrine disruptor potential of BPA is well known, but recent researches suggest a relationship between chronic exposure to BPA, genotoxic activity and epigenetic modifications.The main source of exposure to BPA includes food contact materials (FCM). Thus simple and robust test methods are needed to improve the migration test of BPA. In this work, a non-separative, easy, fast and inexpensive spectrofluorimetric method based on the second order calibration of excitation-emission fluorescence matrices (EEMs) was proposed for the determination of BPA. For the first time, molecular fluorescence was used to identify unequivocally and quantify BPA. Trilinearity of the data tensor guarantees the uniqueness of the solution obtained through parallel factor analysis (PARAFAC), so one factor of the decomposition matches up with BPA even if other fluorophores are in the test sample.The effect of four experimental factors of the procedure on the figures of merit and the unequivocally identification was investigated by means of a D-optimal design and PARAFAC calibration. The method is linear and accurate in the range 0–720µgL⁻¹. The decision limit CCα and detection capability CCβ are 6.63µgL⁻¹ and 18.85µgL⁻¹ respectively (with probabilities of false positive and false negative fixed at 0.05).Finally the proposed method was applied to carry out a migration test from two polycarbonate cups, using 3% (w/v) acetic acid in aqueous solution as food simulant. The migrated amount of BPA was found to be 688.7µgL⁻¹ (n=5) for the first cup and 710.5µgL⁻¹ (n=4) for the second one, above the specific migration limit set by EFSA (European Food Safety Authority).

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A quantitative approach for Cd, Cu, Fe and Mn through laser ablation imaging for evaluating the translocation and accumulation of metals in sunflower seeds

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Gustavo de S. Pessôa, Cícero A. Lopes Júnior, Katherine C. Madrid, Marco A.Z. Arruda
The uptake and accumulation of Cd in sunflower seeds represents an important pathway for imputing potentially toxic metals into human and animal food. In this way, bioimaging of Cd and micronutrients (Cu, Fe and Mn) in the seeds of sunflower grown in soil contaminated with Cd are performed. For this task, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used in quantitative approach, considering four groups: precursor, control, Cd-low (50mg) and Cd-high (700mg). For attaining our proposals, ICP-MS (nebulizer and auxiliary flow rates and radiofrequency power) and LA (laser intensity, frequency and spot size) parameters were optimized, and the analytical signal improved to 197%, 217%, 232%, and 283%, for ⁵⁷Fe, ¹¹²Cd, ⁵⁵Mn and ⁶³Cu, respectively. The accuracy of proposed method using LA-ICP-MS is evaluated comparing the CRM results (Tomato leaves, NIST SRM 1573a). No difference is found at 95% confidence level. Regarding Cd accumulation in sunflower seeds, the results indicated that cadmium is translocated to seeds, and the cotyledons showed the highest concentration (Cd-high group), ranging from 10 to 20µgg⁻¹. Considering both total concentration and the distribution in the seeds, Cd uptake is responsible to the homeostasis misbalance of micronutrients, which play an essential role in the sunflower metabolism. Such results highlight the importance of bioimaging evaluation, in the translocation and accumulation of metals, contributing to expand the information available of this culture.

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Prediction of organic carbon and total nitrogen contents in organic wastes and their composts by Infrared spectroscopy and partial least square regression

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): M. Sisouane, M.M. Cascant, S. Tahiri, S. Garrigues, M. EL Krati, G.EL Kadiri Boutchich, M.L. Cervera, M. de la Guardia
Middle and near infrared (MIR and NIR) were employed to determine organic carbon (OC) and total nitrogen (TN) in different soil organic amendments including wastes, composts and mixtures of composts and organic wastes. Prediction models based on partial least squares (PLS) regression from the spectra of untreated samples were built. Different spectra preprocessing strategies were adopted and the best number of latent variable was evaluated using leave-one-out cross-validation. Attenuated total reflectance (PLS-ATR-MIR) and diffuse reflectance (PLS-DR-NIR) models were built and evaluated from root mean square error of cross validation and prediction (RMSECV and RMSEP), coefficients of determination for prediction (R² pred) and residual predictive deviation (RPD). ATR-MIR provided a better prediction capability than DR-NIR with RMSEP, R²pred and RPD values of 2.2%, 0.76 and 2.0 for OC and values of 0.2%, 0.82 and 2.4 for TN, respectively.

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Facile visual colorimetric sensor based on iron carbide nanoparticles encapsulated in porous nitrogen-rich graphene

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Siyuan Wu, Hao Huang, Xun Feng, Cuicui Du, Wenbo Song
Herein, via one-step pyrolysis of glucose, dicyandiamide (DCDA) and Fe containing metal–organic framework (Fe-MOF), small Fe3C nanoparticles were in-situ decorated in 3D porous network of N-rich graphene (NGr). The Fe-MOF served as size regulating precursor, layered g-C3N4 (derived from pyrolysis of DCDA) acted as not only a template to guide the growth of small Fe3C nanoparticles, but also the carbon source for 3D porous NGr network. The intrinsic peroxidase-like catalytic activity of Fe3C/NGr was unpredictably discovered, by taking the oxidation reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) with H2O2 as a protocol. Fast and distinguished color change, improved stability in exposure to extreme H2O2 concentration and high temperature were obtained. The Michaelis–Menten kinetics was investigated. The detection of glucose was accomplished over a wide concentration range of 2.0~500.0μM with a detection limit lower than most of other similar systems. The reliability of the present sensor was further evaluated by practical monitoring glucose in diluted serum samples. Low cost and simple preparation, fast and distinguished color change, high tolerance to extreme H2O2 concentration and high temperature, endow Fe3C/NGr as one of the promising materials for fast visual colorimetry.

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Quantification of polybrominated diphenyl ethers (PBDEs) in food. A review

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Wojciech Jerzy Pietroń, Paweł Małagocki
The polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants (BFRs), are food contaminants of animal origin. Interest in food matrices analysis is growing due to the toxicity of PBDEs and European Commission (EC) recommendation (118/2014/EU). Here we review papers concerning methods of PBDEs analysis while focusing on extraction, clean up, chromatographic separation and detection techniques. The emphasis is put on EC recommendation, the congeners and the efficiency of different detection systems. Some analytical problems caused by differences between low- and high-molecular-mass congener properties, especially the possible limitations of BDE-209 analysis, are discussed. Detection techniques and mass spectrometry (MS) ionization modes applied to PBDE level determination in food of animal origin are compared. The gas chromatography (GC) coupled to high-resolution MS is undoubtedly fit for that purpose, but ion trap MS could be used to PBDEs determination as well. ECD is the most sensitive technique; however, other halogen compounds present in sample may interfere with PBDEs congeners necessitating results confirmation. Moreover, the novel atmospheric pressure chemical ionization (APCI) method applied to GC in tandem with MS places this technique in the top category of the most sensitive techniques which may be used.

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Ferrocene-graphene sheets for high-efficiency quenching of electrochemiluminescence from Au nanoparticles functionalized cadmium sulfide flower-like three dimensional assemblies and sensitive detection of prostate specific antigen

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Jiu-Jun Yang, Jun-Tao Cao, Hui Wang, Yan-Ming Liu, Shu-Wei Ren
A signal-switchable electrochemiluminescence (ECL) aptasensor was presented for sensitive prostate specific antigen (PSA) assay using ferrocene-graphene sheets (Fc-GNs) for high-efficiency quenching of ECL from Au nanoparticles functionalized cadmium sulfide flower-like three dimensional (3D) assemblies (Au-CdS flower-like 3D assemblies). Au-CdS flower-like 3D assemblies were synthesized and employed as luminophore, exhibiting strong and stable ECL intensity, and followed by assembling captured DNA (cDNA) and hybridizing it with half of base sequence of PSA aptamer on the Au-CdS flower-like 3D assemblies modified electrode. The remaining part of the non-complementary base of the aptamer could preferentially adsorb GN with the signal switched "off" state. While in the presence of the PSA, the binding of PSA with aptamer caused desorption of aptamer from the surface of Fc-GNs and was then released from electrode surface, thus allowing the ECL signal enhancement. With the transformation of luminescence signal from "off" to "on", the aptasensor displays high sensitivity for PSA detection with a linear range from 1pgmL⁻¹ to 25ngmL⁻¹ and a detection limit of 0.38pgmL⁻¹S/N=3). Moreover, this developed method could be successfully applied to the determination of PSA in human serum samples with recoveries of 85.8–104.0%, suggesting great potential applications in biochemical analysis.

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Identification and determination of synthetic cannabinoids in herbal products by dry film attenuated total reflectance-infrared spectroscopy

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Victor de la Asunción-Nadal, Sergio Armenta, Salvador Garrigues, Miguel de la Guardia
A new procedure has been developed for the identification and quantitative determination of synthetic cannabinoids in illicit herbal preparations. The methodology is based on the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) measurement of sample extracts with 2-propanol drying 5µL of the extracts onto the ATR crystal. The qualitative identification was carried out on the 2-propanol extract after identification of the herbal matrix, followed by its subtraction and using a cut-off criterion of 75%. Quantitative determination was made by univariate calibration using the absorbance of the band located at 1520cm^-1 of the spectrum. Four different cannabinoids, RCS-4, JWH-210, UR-144 and JWH-081 were used as test analytes and the ATR-FTIR method provided limits of quantification from 14 till 79mgL^-1. Sized blank market samples were successfully identified and UR-144 quantified.

Graphical abstract

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Glycine post-synthetic modification of MIL-53(Fe) metal–organic framework with enhanced and stable peroxidase-like activity for sensitive glucose biosensing

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Wenfei Dong, Liaoyuan Yang, Yuming Huang
A facile and rapid post-synthetic strategy was proposed to prepare a glycine functionalized MIL-53(Fe), namely glycine-MIL-53(Fe), by a simple mixing of water dispersible MIL-53(Fe) and glycine. The FT-IR, SEM, XRD and zeta potential were used to characterize the glycine-MIL-53(Fe). The result showed that glycine post-synthetic modification of MIL-53(Fe) did not change in the morphology and crystal structure of MIL-53(Fe). Interestingly, compared with MIL-53(Fe), the glycine-MIL-53(Fe) exhibits an enhanced peroxidase-like activity, which could catalyze the oxidation of TMB by H2O2 to produce an intensive color reaction. Kinetic analysis indicated that the Km of glycine-MIL-53(Fe) for TMB was one-tenth of that of MIL-53(Fe). The glycine-MIL-53(Fe) as peroxidase mimetic displays better stability under alkaline or acidic conditions than MIL-53(Fe). The good performance of glycine-MIL-53(Fe) over MIL-53(Fe) may be attributed to the increase of affinity between TMB and the glycine-MIL-53(Fe). With these characteristics, a simple and sensitive method was developed for the detection of H2O2 and glucose. The linear detection range for H2O2 is 0.10–10μM with a detection limit of 49nM, and glucose could be linearly detected in the range from 0.25 to 10μM with a detection limit of 0.13μM. The proposed method was successfully used for glucose detection in human serum samples.

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Novel immunochromatographic assay on cotton thread based on carbon nanotubes reporter probe

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Li-Li Meng, Ting-Ting Song, Xun Mao
In this article, a novel immunochromatographic assay method on cotton thread based on carbon nanotubes (CNTs) as reporter probe was successfully prepared for visual and rapid detection of a lung cancer related biomarker, human ferritin antigen. A model system comprising ferritin as an analyte was used to demonstrate the protocol of the cotton thread immunoassay device. The device can detect at least 50ng/mL human ferritin antigen, which improved the sensitivity approximately by 500 folds comparing with previous point-of-care test report based on carbon nanotubes as reporter probe. The CNTs reporter probe combined with cotton thread device based biosensor provided an alternative path for clinical diagnosis of other protein or nucleic acid biomarkers.

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Efficient extraction of low-abundance peptides from digested proteins and simultaneous exclusion of large-sized proteins with novel hydrophilic magnetic zeolitic imidazolate frameworks

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Man Zhao, Yiqin Xie, Hemei Chen, Chunhui Deng
Zeolitic imidazolate frameworks (ZIFs) are composed of tetrahedral transition metal ions and imidazolate type organic linkers. This kind of metal organic frameworks (MOFs) combines the unique properties of both zeolites and MOFs. Furthermore, ZIFs can be assembled under mild biocompatible conditions. These advantages make them be primarily studied for biochemical analysis. In this work, polydopamine-modified hydrophilic magnetic ZIFs were synthesized in a simple and mild way for the efficient extraction of low-abundance peptides. Thanks to the low-coordinated Zn²⁺ ions, the Fe3O4@PDA@ZIF-8 composites showed strong affinity towards low-abundance peptides, especially those with histidine residues. After enrichment, the sequence coverage of BSA and HSA tryptic digest got a significant increase. The solid phase method based on the magnetic ZIFs exhibited size-exclusion effect towards large-sized proteins, and proved to be effective even under the 200-fold dilution with BSA protein solution.

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Optimization and validation of the methods for the total mercury and methylmercury determination in breast milk

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Véronique Vacchina, Fabienne Séby, Rachida Chekri, Justine Verdeil, Jean Dumont, Marion Hulin, Véronique Sirot, Jean-Luc Volatier, Raphaël Serreau, Alexandra Rousseau, Tabassome Simon, Thierry Guérin
The objective of the work was to develop and validate methods for the total Hg and methylmercury (MeHg) in breast milk that could be further used to obtain first data on chemical contamination of French breast milk. For total Hg determination, the potential of two techniques, namely Advanced Mercury Analyzer (AMA) and ICP MS, was compared. For MeHg determination, ICP MS detection associated to a quantification by isotopic dilution was used and the potential of a preliminary separation by gas or liquid chromatography was evaluated and discussed. The optimization studies have shown that AMA for total Hg determination and HPLC – ID – ICP MS, after a preconcentration step by freeze-drying, for MeHg quantification were the most relevant methods to use for epidemiologic studies. The figures of merit for both methods were evaluated by means of accuracy profiles in terms of limits of quantification (1.82 and 1.35µg Hg/kg dry weight, corresponding to 0.22 and 0.16µg Hg/kg wet basis for total Hg and MeHg, respectively), repeatability (2–11% and 3–8% for total Hg and MeHg respectively), intermediate precision reproducibility (4–12% and 4–8% for total Hg and MeHg respectively) and trueness bias (−0.1–9% and −4–0% for total Hg and MeHg respectively). The methods were then applied to 180 breast milk samples. Total Hg concentrations ranged from <LD to 16.9µg Hg/kg wet basis (<LD to 142µg Hg/kg dry weight) and the MeHg contents from <LD to 0.43µg Hg/kg wet basis (<LD to 3.67µg Hg/kg dry weight).

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