Source:Acta Histochemica, Volume 120, Issue 3
https://ift.tt/2GuSdaA
Publication date: Available online 27 March 2018
Source:Acta Biomaterialia
Author(s): Jean-Philippe Buffet, Erwan Corre, Evelyne Duvernois-Berthet, Jérôme Fournier, Pascal Jean Lopez
Tube-building sabellariid polychaetes are hermatypic organisms capable of forming vast reefs in highly turbulent marine habitats. Sabellariid worms assemble their tube by gluing together siliceous and calcareous clastic particles using a polyelectrolytic biocement. Here, we performed transcriptomic analyses to investigate the genes that are differentially expressed in the parathorax region, which contains the adhesive gland and tissues, from the rest of the body. We found a large number of candidate genes to be involved in the composition and formation of biocement in two species: Sabellaria alveolata and Phragmatopoma caudata. Our results indicate that the glue is likely to be composed by a large diversity of cement-related proteins, including Poly(S), GY-rich, H-repeat and miscellaneous categories. However, sequences divergence and differences in expression profiles between S. alveolata and P. caudata, of cement-related proteins may reflect adaptation to the type of substratum used to build their tube, and/or to their habitat (temperate vs tropical, amplitude of pH, salinity ...). Related to the L-DOPA metabolic pathways and linked with the genes that were differentially expressed in the parathorax region, we found that tyrosinase and peroxidase gene families may have undergone independent expansion in the two Sabellariidae species investigated. Our data also reinforce the importance of protein modifications in cement formation. Altogether these new genomic resources help to identify novel transcripts encoding for cement-related proteins, but also important enzymes putatively involved in the chemistry of the adhesion process, such as kinases, and may correspond to new targets to develop biomimetic approaches.Statements of SignificanceThe diversity of bioadhesives elaborated by marine invertebrates is a tremendous source of inspiration to develop biomimetic approaches for biomedical and technical applications. Recent studies on the adhesion system of mussel, barnacle and sea star had highlighted the usefulness of high-throughput RNA sequencing in accelerating the development of biomimetic adhesives. Adhesion in sandcastle worms, which involves catechol and phosphate chemistries, polyelectrolyte complexes, supramolecular architectures, and a coacervation process, is a useful model to develop multipurpose wet adhesives. Using transcriptomic tools, we have explored the diversity of genes encoding for structural and catalytic proteins involved in cement formation of two sandcastle worm species, Sabellaria alveolata and Phragmatopoma caudata. The important genomic resource generated should help to design novel "blue" adhesives.
Publication date: Available online 26 March 2018
Source:Acta Biomaterialia
Author(s): Hua Shi, Runqi Yan, Luyan Wu, Yidan Sun, Song Liu, Zhengyang Zhou, Jian He, Deju Ye
Precise diagnosis of lymph node metastasis to guide lymphadenectomy is highly important for gastric cancer therapy in clinics. Though surgical dissection of regional metastatic lymph nodes remains the only way for gastric cancer therapy, the extended dissection may cause unavoidable postoperative risk of complications. These is still lack of effective method enabling the accurate removal of metastatic gastric cancer cells in lymph nodes with minimum injuries to normal tissue. Herein, we report a new fluorescent copper sulfide (CuS) nanoparticle (RGD-CuS-Cy5.5) enabling both non-invasive multimodality imaging and targeting photothermal therapy (PTT) of metastatic gastric cancer cells in lymph nodes. We demonstrate that RGD-CuS-Cy5.5 can easily drain into sentinel lymph nodes (SLN) after injection into primary tumors, and selectively enter into metastatic gastric MNK45 tumor cells via αvβ3 integrin-mediated endocytosis. The resulting strong near-infrared (NIR) fluorescence and computed tomography (CT) contrast in metastatic SLN compared to normal SLN can precisely differentiate SLN metastasis of gastric cancers. Guided by the imaging, localized PTT with RGD-CuS-Cy5.5 is conducted upon irradiation with an 808 nm laser, resulting in complete removal of metastatic gastric tumor cells in SLN without obvious toxicity. Moreover, RGD-CuS-Cy5.5 can also allow for the rapid and non-invasive self-monitoring of PTT efficacy against metastatic SLNs in living mice. This study highlights the potential of using RGD-CuS-Cy5.5 for imaging-guided and targeting PTT of SLN metastasis in vivo, which may be applicable for the metastatic gastric cancer therapy in clinics.Statement of SignificanceRGD-CuS-Cy5.5 nanoparticles possess NIR fluorescence and CT signals for in vivo bimodality imaging of lymph node metastasis.Strong photothermal property under irradiation at 808 nm for efficient PTT.Easy drain into sentinel lymph nodes and selective enter metastatic gastric cancer cells via αvβ3 integrin-mediated endocytosis.Rapid and non-invasive monitoring of therapeutic efficacy against lymph node metastasis.
Publication date: Available online 26 March 2018
Source:Acta Biomaterialia
Author(s): Soyon Kim, Zhong-Kai Cui, Paul Jay Kim, Lawrence Young Jung, Min Lee
Although bone morphogenetic protein-2 (BMP-2) is known to be the most potent stimulator available for bone formation, a major barrier to widespread clinical use is its inherent instability and absence of an adequate delivery system. Heparin is being widely used in controlled release systems due to its strong binding ability and protective effect for many growth factor proteins. In this work, we developed a hydrogel surface that can mimic heparin to stabilize BMP-2 and to enhance osteogenesis by introducing heparin-mimicking sulfonated molecules such as poly-vinylsulfonic acid (PVSA) or poly-4-styrenesulfonic acid (PSS), into photo-crosslinkable hydrogel. Bioactivity of BMP-2 was well preserved in the presence of polysulfonates during exposure to various therapeutically relevant stressors. The heparin-mimicking sulfonated hydrogels were effective to bind BMP-2 compared to unmodified MeGC hydrogel and significantly enhanced osteogenic differentiation of encapsulated bone marrow stromal cells (BMSCs) without the addition of exogenous BMP-2. The sulfonated hydrogels were effective in delivering exogenous BMP-2 with reduced initial burst and increased BMSCs osteogenesis induced by BMP-2. These findings suggest a novel hydrogel platform for sequestering and stabilizing BMP-2 to enhance osteoinductive activity in bone tissue engineering.Statement of significanceAlthough bone morphogenetic protein-2 (BMP-2) is believed to be the most potent cytokine for bone regeneration, its clinical applications require supraphysiological BMP dosage due to its intrinsic instability and fast enzymatic degradation, leading to worrisome side effects. This study demonstrates a novel hydrogel platform that mimics a natural protector of BMPs, heparin, to sequester and stabilize BMP-2 for increased osteoinductive signaling. This study will achieve the stabilization of BMPs with prolonged bioactivity by a synthetic heparin mimic that has not been examined previously. Moreover, the heparin mimetic hydrogel surface can augment endogenous BMP activity by sequestering and localizing the cell-produced BMPs. The additional knowledge gained from this study may suggest basis for future development of material-based therapeutics for tissue engineering.
Publication date: Available online 26 March 2018
Source:Acta Biomaterialia
Author(s): Hua Zhang, Shan Yu, Xinlian Zhao, Zhengwei Mao, Changyou Gao
Intervertebral disc (IVD) degeneration may cause many diseases and pain. Stem cell migration toward the site of IVD degeneration is a key factor for IVD regeneration. In the current study, we prepared albumin/heparin nanoparticles (BHNPs) as injectable carriers of stromal cell-derived factor-1α (SDF-1α, also known as C-X-C motif chemokine 12), a powerful chemoattractant for the homing of bone marrow resident mesenchymal stem cells (MSCs), for protection of the molecule against degradation for a sustained release. The NPs have relatively uniform small size, with a diameter of about 110 nm. The NPs possess a high loading capacity of SDF-1α with a sustained release profile. The bioactivity of the obtained BHNPs/SDF was then studied in vitro and in vivo. The BHNPs/SDF can induce migration of MSCs in a dose-dependent manner in vitro. After injected into the damaged disc, BHNPs/SDF induce much better regeneration of annulus fibrosus and nucleus pulposus, compared to SDF-1α and BHNPs alone, evidenced with better histological grade scores and higher expression of SOX9, Aggrecan, and Collagen type II at the level of both mRNA and protein. This study provides a simple nanoplatform to load SDF-1α and protect it against degradation, with potential application in inductive tissue regeneration in vivo.Statement of significanceStem cell migration toward the site of IVD degeneration is a key factor to help IVD regeneration. In current study, we prepared albumin/heparin nanoparticles (BHNPs) as injectable carriers to protect and sustained release of SDF-1α. After injected into damaged disc, BHNPs/SDF induce much better regeneration of IVD, compared to SDF-1α and BHNPs alone. This study provides a simply nanoplatform to load and protect SDF-1α, with potential application in inductive tissue regeneration in vivo.
Publication date: Available online 27 March 2018
Source:Acta Biomaterialia
Author(s): Srinidhi Nagaraja, Stacey J.L. Sullivan, Phillip R. Stafford, Anne D. Lucas, Elon Malkin
Although nitinol is used widely in percutaneous cardiovascular interventions, a causal relationship between nickel released from implanted cardiovascular devices and adverse systemic or local biological responses has not been established. The objective of this study was to investigate the relationship between nitinol surface processing, in-vivo nickel release, and biocompatibility. Nitinol stents manufactured using select surface treatments were implanted into the iliac arteries of minipigs for 6 months. Clinical chemistry profile, complete blood count, serum and urine nickel analyses were performed periodically during the implantation period. After explant, stented arteries were either digested and analyzed for local nickel concentration or fixed and sectioned for histopathological analysis of stenosis and inflammation within the artery. The results indicated that markers for liver and kidney function were not different than baseline values throughout 180 days of implantation regardless of surface finish. In addition, white blood cell, red blood cell, and platelet counts were similar to baseline values for all surface finishes. Systemic nickel concentrations in serum and urine were not significantly different between processing groups and comparable to baseline values during 180 days of implantation. However, stents with non-optimized surface finishing had significantly greater nickel levels in the surrounding artery compared to polished stents. These stents had increased stenosis around stent struts with potential for local inflammation compared to polished stents. These findings demonstrate that proper polishing of nitinol surfaces can reduce in-vivo nickel release locally, which may aid in minimizing adverse inflammatory reactions and restenosis.Statement of SignificanceNitinol is a commonly used material in cardiovascular medical devices. However, relationships between nitinol surface finishing, in-vivo metal ion release, and adverse biological responses have yet to be established. We addressed this knowledge gap by implanting single and overlapped nitinol stents with different surface finishes to assess systemic impact on minipigs (i.e. serum and urine nickel levels, liver and kidney function, immune and blood count) over the 6 month implantation period. In addition, nickel levels and histopathology in stented arteries were analyzed on explant to determine relationships between surface processing and local adverse tissue reactions. The findings presented here highlight the importance of surface processing on in-vivo nickel release and subsequent impact on local biological response for nitinol implants.
Publication date: Available online 27 March 2018
Source:Molecular and Cellular Endocrinology
Author(s): Karolina Nowak, Wioletta Ratajczak–Wrona, Maria Górska, Ewa Jabłońska
Preservatives (ingredients which inhibit growth of microorganisms) are used to prolong shelf life of various foods, cosmetics, and pharmaceutical products. Parabens are one of the most popular preservatives used in the aforementioned products and is currently being used worldwide. Parabens are easily absorbed by the human body. Thus, it is important to discuss about their safety with respect to human physiology. In view of the current literature, which classifies parabens as a group of endocrine disrupting chemicals (EDCs), it seems that the precise assessment of their influence on the human endocrine system is particularly important. Disruption of the endocrine homoeostasis might lead to multidirectional implications causing disruption of fitness and functions of the body. Therefore, in this review article, we aimed to summarize the current literature on properties, occurrence, and metabolism of parabens as well as to present recent progress in knowledge about their influence on the human endocrine system.
Publication date: Available online 26 March 2018
Source:Molecular and Cellular Endocrinology
Author(s): M.S. Webb, A.L. Miller, T.L. Howard, B.H. Johnson, S. Chumakov, Y. Fofanov, T. Nguyen-Vu, C.Y. Lin, E.B. Thompson
Gene expression responses to glucocorticoid (GC) in the hours preceding onset of apoptosis was compared in three clones of human acute lymphoblastic leukemia CEM cells. Between 2 and 20 h, all three clones showed increasing numbers of responding genes. Each clone had many unique responses, but the two responsive clones showed a group of responding genes in common, different from the resistant clone. MYC levels and the balance of activities between the three major groups of MAPKs are known important regulators of glucocorticoid-driven apoptosis in several lymphoid cell systems. Common to the two sensitive clones were changed transcript levels from genes that decrease amounts or activity of anti-apoptotic ERK/MAPK1 and JNK2/MAPK9, or of genes that increase activity of pro-apoptotic p38/MAPK14. Down-regulation of MYC and several MYC-regulated genes relevant to MAPKs also occurred in both sensitive clones. Transcriptomine comparisons revealed probable NOTCH-GC crosstalk in these cells.
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Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Purim Jarujamrus, Nutthaporn Malahom, Sodsai Puchum, Rattapol Meelapsom, Maliwan Amatatongchai, Atitaya Siripinyanond, Sanoe Chairam, Chadin Kulsing
This work describes analytical approaches based on simple complexometric and argentometric titrations leading to the color change of a novel microfluidic thread-based analytical device (µTAD). The device was fabricated from a cotton thread (15 cm) treated with indicator solution, providing an easy-to-use platform for rapid measurement of analyte concentration in aqueous solution. The thread was immobilized onto a support, being a polypropylene sheet or box platform, to facilitate loading of liquid samples. Interaction between the deposited reagents and analytes in the samples then occurred within a few minutes. This resulted in zones of color change with different lengths along the thread depending on the analyte concentration. The interaction zones can be analyzed by human eyes based on comparison of the zone lengths with the printed scales which are correlated with the analyte concentrations. Complexometric titration using µTADs was initially investigated for Mg(II) determination in water and rubber latex samples. These devices consisted of two threads which were pretreated with Eriochrome Black T (EBT) and then treated with ethylenediaminetetraacetic acid (EDTA) in N-cyclohexyl-3-aminopropanesulfonic acid (CAPS) buffer at pH 10. Both threads were tied together with a central knot before being attached to the box platform prior to the analysis. Load of sample solution (6 µL) resulted in the length of red-violet color product on the threads being proportional to the concentration of Mg(II) in waters and rubber latex samples with the working concentration range of 25–1000 mg L−1. In addition, µTAD with a supporting polypropylene sheet consisting of several threads treated with AgNO3 and K2CrO4 indicators was applied for argentometric titration of chloride ion in water and food seasoning samples. After sample loading (3 µL), the initially red-brown threads turned into white corresponding to formation of AgCl(s) on the threads with a working concentration range of 75–600 mg L−1. Greater selectivity towards Mg(II) and chloride compared with potential interference ions was also observed. All the developed μTADs were applied for analysis of real samples which showed results being in agreement with those obtained by classical titrations.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Viktor V. Pervukhin, Dmitriy G. Sheven
The method of ionization by aerodynamic droplet breakup is considered for applications in mass spectrometric analysis. It is assumed that Aerodynamic Breakup Droplet Ionization (ABDI) occurs in a tube linking the region of atmospheric pressure to the area of weak vacuum. The possibility of ionization of solutions of organic compounds and organometallic complexes is shown. As test compounds were chosen: heroin (as an example of organic compounds) and organometallic complexes of ruthenium and copper, dissolved in water or acetonitrile. The quality of the ABDI spectra depends on the analyte. In general, the analytes ionized by the ABDI method show a great propensity to form dimers and trimers. ABDI system can be easily installed on any mass spectrometer with inlet at atmospheric pressure and used as an additional method. Since compounds prone to degradation in ESI analysis are better suited for ABDI analysis, this seems useful.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): T. Alexandra Ferreira, José A. Rodríguez, Carlos A. Galán-Vidal, Yolanda Castrillejo, Enrique Barrado
In this work an electrochemical procedure for Cr(VI) flow based determination in tap water is presented. An AdCSV method was developed using a screen printed electrode modified with magnetic poly(1-allyl-3-methylimidazolium) chloride and the procedure does not require the addition of complexing agents in the solution unlike the methodologies reported so far for Cr(VI) determination. The flow based system is described and the control variables were studied in detail and optimized using a Taguchi parameters design. Under optimal conditions, the electrochemical sensor offered an excellent response to Cr(VI) and the limit of detection estimated from 3σ was 0.5 µg L−1 (n = 3) allowing the analysis of tap water samples. The effect of interfering ions was also investigated below the maximum permissible limits for tap water according to Mexican standards. The presence of the magnetic particles on the sorbent allowed its easy modification on the electrode surface between each determination when removing the magnetic field placed in the wall-jet cell. Finally, the precision of the method was tested with tap water samples using standard addition method for Cr(VI) quantification and the accuracy was evaluated comparing the results with the dyphenylcarbazide method and by analyzing a certified water sample. The method shows good repeatability and reproducibility (%RSD less than 5%) making it feasible for Cr(VI) flow based determination and no significant difference is observed in the results obtained by both methods.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Qiao-Qiao Li, Feng-Qing Yang, Yin-Zhen Wang, Zhao-Yu Wu, Zhi-Ning Xia, Hua Chen
An online capillary electrophoresis (CE)-based thrombin (THR) immobilized enzyme microreactor (IMER) method was established to screen THR inhibitors in this study. S-2366 was used as chromogenic substrate for determination of THR activity and other kinetic constants. After continuously run for 50 times, the prepared IMER could still remain 89% of the initial immobilized enzyme activity. The Michaelis-Menten constant (Km) of immobilized THR was measured as 0.514 mmol/L and the half-maximal inhibitory concentration (IC50) and inhibition constant (Ki) of argatroban on THR were determined as 78.07 and 26.53 nmol/L, respectively, which indicated that CE-based THR IMER was successfully established and could be applied to screen THR inhibitors. Then the prepared IMER was used to investigate the inhibitory potency on THR of four main catechins in green tea including epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG). The results showed that ECG and EGCG had good THR inhibition activity and their inhibition rates at concentration of 200 μmol/L were 53.2 ± 3.8% and 55.8 ± 2.6%, respectively, which was in consistent with the results of microplate reader assay. Additionally, molecular docking results showed that the benzopyran groups of ECG and EGCG were inserted into the THR active pocket and interacted with residues LYS60F, TRP60D, TRY60A, IEU99, GLY216, HIS57 and SER195, but EC and EGC did not. Therefore, the developed CE-based THR IMER is reliable method for measuring THR inhibitory activity of natural inhibitors.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): JingHong Li, Nan Chen, YiPing Tian, Hui Xu
The exploration of volatile organic compounds (VOCs) produced by cell lines may be a powerful and non-invasive tool for the study of the health risk of human exposure to atmospheric particulate matter (PM). In this work, we developed a sensitive solid phase microextraction-gas chromatography-mass spectrometry method (SPME-GC-MS) to analyze VOCs in breathed gas of PM2.5-induced human embryonic fibroblast cell line (MRC-5). A novel graphene oxide/polyaniline/polydopamine (GO/PANI/PDA) coating was prepared on a stainless steel wire via electrochemical deposition and self-polymerization for the first time. The GO/PANI/PDA coating exhibited high extraction efficiency, good thermal stability (> 380 ℃), excellent mechanical stability as well as long service time (> 150 times). Parameters that may affect the results were optimized systematically. Under the optimal conditions, VOCs including benzene series, aldehydes and alkane were detected with low limit of detection (0.2–2.0 μg L−1) and good correlation (correlation coefficients above 0.9922). The relative standard deviations of within-day and between-day were 1.1–8.4% and 0.2–11.2%, respectively. Satisfactory recoveries of 82–117% indicated good repeatability of the method. The method has been successfully applied for the determination of target VOCs in the headspace gas of PM2.5-induced MRC-5 cell. And it is expected to provide an alternative tool for the study of cytotoxicology of atmospheric particulates.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Xueguang Shao, Xiaoyu Cui, Xiaoming Yu, Wensheng Cai
Temperature dependent near infrared (NIR) spectroscopy has been developed for analyzing multi–component mixtures and understanding the molecular interactions in solutions. In this work, a chemometric method named as mutual factor analysis (MFA) was proposed for the analysis of temperature dependent NIR spectra. The method extracts the common spectral feature contained in the spectra of different temperature or different concentration. The relative quantity of the extracted spectral feature is proportional to the temperature or concentration. From the spectra of water–glucose mixtures, both the spectral variations induced by temperature and concentration are obtained and the variations are correlated with the inducements, respectively, in a very good linearity. Serum samples were used for validation of the method. An acceptable calibration model with a good correlation coefficient (R2 = 0.8639) was obtained for glucose measurement. The relative deviations of the measured concentrations from the calibration model are in the range of –18.7–8.52%, which are in a reasonable level for clinical uses. More importantly, the calculations are based on the spectral information of water that has interactions with the analyte. This provides a new way for quantitative analyses of bio–systems.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Yan Wu, Tingting Jiang, Zhaoyang Wu, Ruqin Yu
A ratiometric surface-enhanced Raman scattering (SERS) aptasensor based on internal standard (IS) methods was proposed for the ultrasensitive and reproducible quantitative detection of silver ion (Ag+) with Au@Ag core-shell nanoparticle (Au@Ag NP) substrate. In principle, the thiolated 5′-Rox C-containing labeled aptamer probe (Rox-aptamer) is firstly immobilized on the SERS substrate surface and then hybridizes with the complementary DNA (cDNA) to form a rigid double-stranded DNA (dsDNA), in which the Rox Raman labels is used to produce the Raman signal. Furthermore, the pyridine is employed as an IS element to provide the ratiometric determination of target. In the presence of Ag+, the Rox-aptamer is turned into the cytosine (C)-Ag+-C mediated hairpin structure, which remarkably reduces the distance between the Rox labels and the Au@Ag NP surface responsible for a measurable 'turn-on' signal change of Rox. This IS-based ratiometric SERS aptasensor exhibits a limit of detection of 50 pM for Ag+ with a linear detection range from 0.1 to 100 nM and the shortcoming of irreproducibility of SERS signal could be overcome. The proposed method provides a simple, robust, and rapid approach for the sensitive and reproducible quantitative detection of Ag+, and it could also be used for the detection of other metal ions which exhibits specific interactions with natural or synthetic bases.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Elodie Mattio, Fabien Robert-Peillard, Laurent Vassalo, Catherine Branger, André Margaillan, Christophe Brach-Papa, Joël Knoery, Jean-Luc Boudenne, Bruno Coulomb
In recent years, the development of 3D printing in flow analysis has allowed the creation of new systems with various applications. Up to now, 3D printing was mainly used for the manufacture of small units such as flow detection cells, preconcentration units or mixing systems. In the present study, a new 3D printed lab-on-valve system was developed to selectively quantify lead and cadmium in water. Different technologies were compared for lab-on-valve 3D printing. Printed test units have shown that stereolithography or digital light processing are satisfactory techniques for creating complex lab-on-valve units. The lab-on-valve system was composed of two columns, eight peripheral ports and a central port, and a coil integrating baffles to increase mixing possibilities. A selective extraction of lead was first carried out by TrisKem Pb™ Resin column. Then, cadmium not retained on the first column was extracted on a second column of Amberlite® IR 120 resin. In a following step, lead and cadmium were eluted with ammonium oxalate and potassium iodide, respectively. Finally, the two metals were sequentially detected by the same Rhod-5N™ fluorescent reagent. This 3D printed lab-on-valve flow system allowed us to quantify lead and cadmium with a linear response from 0.2 to 15 µg L−1 and detection limits of 0.17 and 0.20 µg L−1 for lead and cadmium, respectively, which seems adapted for natural water analysis.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Kelliton José Mendonça Francisco, Claudimir Lucio do Lago
A 3D-printed cartridge was developed to improve the interface between a capillary electrophoresis instrument and a mass spectrometer. The thermostated airflow from the CE was guided to the entrance of the electrospray source keeping as much as possible the silica capillary in a proper Joule-heating dissipation environment. Hollow 3D-printed walls made of ABS covered by a 0.2 mm thick copper foil on the inner side were used. The cartridge also allows including up to two capacitively coupled contactless conductivity detectors (C4Ds). Experiments about the separation of monoethyl carbonate (a thermally unstable species) shows that the peak area obtained with the original cartridge is only 21% of the value obtained with the 3D-printed cartridge, which demonstrates the improvement in heat dissipation.
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Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Li Li, Minghui Zan, Xingwang Qie, Peng Miao, Juan Yue, Zhimin Chang, Zheng Wang, Fu-Quan Bai, Hong-Xing Zhang, James K. Ferri, Wen-Fei Dong
A new cyanide probe has been prepared by one-step synthesis and evaluated by UV–vis and fluorescent method. This probe is combined by a fluorene part and a hemicyanine group through a conjugated linker, which is found to show rapid response, high selectivity and sensitivity for cyanide anions with significant dual colorimetric and fluorescent signal changes in aqueous solution. An intramolecular charge transfer (ICT) effect plays a key role in the CN− sensing properties, and the details of this mechanism are further supported by DFT and TD-DFT calculations. The theoretical study shows that the introduction of CN- twists the original plane structure and blocks the ICT process in the whole molecule, which brings about the absorption blue-shift and the fluorescence quenching.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Sheng Tang, Xiaomeng Mei, Wei Chen, Shao-Hua Huang, Zheng-Wu Bai
N-Methoxycarbonyl chitosan was prepared by selectively modifying the amino group at the 2-position of chitosan with methyl chloroformate, which was further functionalized with p-methylbenzylamine to produce chitosan (p-methylbenzylurea). Then, the hydroxyl groups at the 3- and 6-positions of the glucose skeleton were modified with various phenyl isocyanates, affording a series of chitosan 3,6-bis(arylcarbamate)-2-(p-methylbenzylurea)s, which were characterized and proposed as chiral selectors for enantiomer separation. Nineteen racemates, most of which are drugs or intermediates for drugs, were selected as the model analytes to evaluate the enantioseparation performance. The structure-performance relationship of the chiral selectors was investigated in detail. It was found that the methyl-substituted chiral selectors possessed more preferable enantioseparation performance compared with the chloro-substituted ones, and the chiral selectors containing a methyl substituent at the 4-position of the benzene ring showed the best chiral recognition and separation ability with 17 racemates being recognized and 13 racemates being baseline separated. The prepared chiral separation materials derived from these chiral selectors exhibited favorable solvent tolerance towards ethyl acetate, acetone, chloroform and a low proportion of tetrahydrofuran in normal phase. To sum up, this work provided a useful reference for the design and preparation of high-performance chiral separation materials for efficient enantiomer separation.
Publication date: 1 August 2018
Source:Talanta, Volume 185
Author(s): Francisco M. Hernández-Maya, María P. Cañizares-Macías
β-glucosidase from almonds was immobilized on a polydimethylsiloxane (PDMS) microdevice by covalent chain using 3-aminopropyltrietoxysilane and glutaraldehyde. Enzymatic activity was evaluated using p-nitro-phenyl-β-D-glucopyranoside dissolved in a 0.01 M pH 5.0 phosphate solution at 45 °C measuring the reaction product (p-nitrophenol) at 410 nm. The microdevice consisted of two parts: the one part where the enzymatic reaction was carried out and a second part where pH was adjusted at 10, with NaOH. The reaction product was measured at the microchip exit using two optical fibers which were aligned facing each other with a gap of 7 mm, between both tips using guides located perpendicular to the flow outlet. A water bath was used to carry out the enzymatic reaction on the microdevice at 45 °C. The enzymatic surface of the PDMS microdevice was 1.15 cm2 and the immobilized β-glucosidase amount on the microdevice was of 1.17 µg/cm2. The calculated kinetics parameters were: Km 2.5 mM; Vmax 2.2 mM/min; Kcat 908.3/min and Kcat/Km 363.3/mM min. The immobilized enzyme is very stable decreasing only 5% the first 15 days; on the 30th day, the activity was 69%, regarding the initial activity.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Humberto Cabrera, Jehan Akbar, Dorota Korte, Evelio E. Ramírez-Miquet, Ernesto Marín, Joseph Niemela, Zeinab Ebrahimpour, Kasun Mannatunga, Mladen Franko
In the thermal lens experimental set-up we replaced the commonly employed pump laser by a halogen lamp, combined with an interference filter, providing a tuneable, nearly monochromatic pump source over the range of wavelengths 430–710 nm. Counter-propagating pump and probe beams are used and a 1 mm path-length sample cell together with the interference filter makes an optical cavity, providing amplification of the thermal lens signal, which leads to enhancement of the measurement sensitivity, and enables detection of absorbances on the order of 5 × 10−6. Amplified thermal lens signal allows us to replace the typical lock-in amplifier and digital oscilloscope with a silicon photodetector, Arduino, and a personal computer, offering the possibility for a compact, robust and portable device, useful for in-field absorption measurements in low concentration or weakly absorbing species. The use of a white light source for optical pumping, an interference filter for wavelength selection and direct diagnostic of the thermal lens signal increase the versatility of the instrument and simplifies substantially the experimental setup. Determination of Fe(II) concentrations at parts per billion levels was performed by the described white-light thermal lens spectrophotometer and the absorption spectrum for 50 μgL–1 Fe(II)-1,10-phenanthroline was well reproduced with an average measurement precision of 4%. The obtained limits of detection and quantitation of Fe(II) determination at 510 nm are 3 µgL−1 and 11 µgL−1, respectively. The calibration curve was linear in the concentration range of LOQ-500 µgL−1 with reproducibility between 2% and 6%, confirming that this instrument provides good spectrometric capabilities such as high sensitivity, tuneability and good reproducibility. In addition, the versatility of the instrument was demonstrated by recording the photothermal spectrum of gold nanostructured material and determination of excitation wavelength with most efficient optical to thermal energy conversion, which differs considerably (cca 100 nm) from the absorption maximum of the investigated sample.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Cemil Can Eylem, Mustafa Taştekin, Adnan Kenar
A method was developed to determine copper and zinc simultaneously in brass sample using a multiple ion-selective electrode array system and multivariate calibration techniques. The multiple ion-selective electrode array system was consisted of one pH electrode and eight ion selective electrodes which were formed using commercial ionophores and which are mainly sensitive copper and zinc. PCR, PLS1 which are multivariate calibration techniques were used to calibrate the multiple ion-selective electrode array system using five level multivariate calibration design and PCR method was selected as most suitable method. The measurements were performed at pH 10 in ammonia-ammonium chloride buffer. Copper and zinc content of a brass sample were determined by the calibrated multiple ion-selective electrode array system and the composition of brass sample was also determined by gravimetric method. The percentage amount of copper and zinc in brass sample were 64 ± 1 and 26 ± 2, respectively using the gravimetric method. The percentage results obtained in brass samples for copper and zinc were 63 ± 3 and 24 ± 3 by PCR method and 60 ± 5 and 20 ± 7 by PLS1 method, respectively. The obtained results were calculated for a 95% confidence level.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Roberta Risoluti, Stefano Materazzi, Francesco Sorrentino, Carlotta Bozzi, Patrizia Caprari
A novel approach based on Thermogravimetric analysis followed by Chemometrics (TGA/Chemometrics) is provided for Thalassemia diagnosis and a comprehensive study consisting of the coupled approach TGA/Chemometrics, the Complete Blood Count (CBC) and Red Blood Cell (RBC) indices is developed and results are compared.A number of 128 subjects were involved in this study included 16 thalassemia intermedia transfusion-dependent (TI-TD) patients, 18 thalassemia intermedia non transfusion-dependent (TI-NTD) patients, and 14 thalassemia major β (TM-TD) patients. Thalassemic patients were found to be clearly distinct from healthy donors as a function of a different thermal behavior. The chemometric analysis identifies the differences in the composition of blood and a model of prediction for β-thalassemia was developed and validated to distinguish all patients. TGA/Chemometrics method also permitted to differentiate thalassemic patients according to the severity of anaemia while the evaluation of the indices and the CBC are not able to identify TI-TD, TI-NTD and TM-TD patients at first level test.TGA/Chemometrics was successfully applied for thalassemia diagnosis with 100% of correct classification rate. Chemometric analysis demonstrated that red cell distribution width (RDW), haemoglobin (Hb) and RBC are the diagnostic features in thalassemia compared to mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH). New insights into the significance of the haematological features were provided for an update of the thalassemia classification.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Giorgia La Barbera, Anna Laura Capriotti, Chiara Cavaliere, Francesca Ferraris, Carmela Maria Montone, Susy Piovesana, Riccardo Zenezini Chiozzi, Aldo Laganà
The paper describes the development of an enrichment method for the analysis of the endogenous phosphopeptides in saliva. The method was based on magnetic solid phase extraction by a magnetic graphitized carbon black-TiO2 composite material and was developed considering different saliva pre-treatments, namely C18 solid phase extraction for purification, direct dilution in loading buffer or acetonitrile precipitation. The method was based on a shotgun proteomics workflow and the enriched peptide mixture was analysed by nanoHPLC and high resolution tandem mass spectrometry. Acetonitrile precipitation provided the best results, with up to 165 endogenous phosphopeptides identified in saliva samples from healthy individuals. The physico-chemical features of the identified endogenous phosphopeptides indicated that such peptides were large, hydrophilic and basic.
Publication date: 1 June 2018
Source:Talanta, Volume 183
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Publication date: 1 June 2018
Source:Talanta, Volume 183
https://ift.tt/2IWiWLF
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): George Machairas, Irene Panderi, Ariadni Geballa-Koukoula, Stavroula Rozou, Nikolaos Antonopoulos, Christos Charitos, Ariadni Vonaparti
A hydrophilic interaction liquid chromatography method with diode array detection (HILIC-DAD) was developed and validated for the simultaneous determination of impurities in extended-release fixed-dose combination tablets containing rosuvastatin and metformin in a ratio 1:100. The analytes were separated by hydrophilic interaction liquid chromatography using an XBridge®-HILIC analytical column under isocratic elution. The mobile phase was composed of ammonium formate at 150 mM containing 0.05% diethylamine (pH 8.5)/acetonitrile, 4/96 (v/v) and pumped at a flow rate of 0.5 mL min−1. Method validation was performed according to ICH guidelines. The calibration curves for rosuvastatin, metformin and their seven impurities showed good linearity (r > 0.994) within the calibration ranges tested. The intra- and inter-day R.S.D. values were less than 4.5%, while the relative percentage error Er was less than 2.7% for all compounds. Accelerated stability studies performed under various stress conditions including hydrolysis, oxidation and heat proved the selectivity of the procedure. A run time of less than 25 min for each sample made it possible to analyze a large number of samples per day. The method is the first reported application of HILIC for the analysis of impurities in fixed-dose combination tablets containing rosuvastatin and metformin and it can be used for the quality control of these drugs.
Publication date: 1 June 2018
Source:Talanta, Volume 183
Author(s): Heshmatollah Alinezhad, Amirhassan Amiri, Mehrasa Tarahomi, Behrooz Maleki
A novel polyamidoamine dendrimer functionalized with Fe3O4 nanoparticles (Fe3O4@PAMAM) had been fabricated and used as magnetic solid-phase extraction (MSPE) adsorbent. The Fe3O4@PAMAM nanocomposites were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron spectroscopy, elemental analytical, and thermal gravimetric analysis. The MSPE method coupled with high-performance liquid chromatography with an ultraviolet detection system was applied for the separation/analysis of non-steroidal anti-inflammatory drugs (NSAIDs). Major parameters affecting the extraction efficiency of the selected drugs were optimized. Under optimal conditions, the enrichment factors for the proposed method were 701835. The linear range, limit of detection, correlation coefficient (r), and relative standard deviation (RSD) were found to be 0.15–500 ng mL−1, 0.050.08 ng mL−1, 0.99320.9967, and 4.5–7.0% (n = 5, 0.2, 10 and 300 ng mL−1), respectively. The method was successfully applied to the determination of NSAIDs in the real water samples. The recoveries of spiked water samples were in the range of 93.6–98.9% with RSDs varying from 6.1% to 9.0%, showing the good accuracy of the method.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Hongmei Mou
CFTR biosynthesis is highly dynamic. In this issue of Developmental Cell, Okiyoneda et al. (2018) show that RFFL serves as a CFTR conformation scrutinizer at the plasma membrane. It recognizes misfolded CFTR proteins and marks them for degradation. This quality control mechanism may be explored to benefit cystic fibrosis patients.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Joshua M. Svendsen, Taiowa A. Montgomery
piRNAs are known to silence transposable elements, but not all piRNAs match transposon sequences. Recent studies from Shen et al. (2018) and Zhang et al. (2018) identify rules for piRNA target recognition in Caenorhabditis elegans. Permissive pairing rules allow targeting of essentially all germline mRNAs, while protective mechanisms prevent silencing self-genes.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Lendert Gelens, Adrian T. Saurin
Protein phosphorylation is a dynamic post-translational modification critical for biological responses. At the level of individual molecules, phosphorylation dynamics can have important functional implications, but this information is rarely quantified. We discuss how rapid phosphorylation-dephosphorylation cycles could underlie important signaling properties, including the ability to rapidly bind and release proteins.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Purushothama Rao Tata, Ryan D. Chow, Srinivas Vinod Saladi, Aleksandra Tata, Arvind Konkimalla, Anne Bara, Daniel Montoro, Lida P. Hariri, Angela R. Shih, Mari Mino-Kenudson, Hongmei Mou, Shioko Kimura, Leif W. Ellisen, Jayaraj Rajagopal
We show that the loss or gain of transcription factor programs that govern embryonic cell-fate specification is associated with a form of tumor plasticity characterized by the acquisition of alternative cell fates normally characteristic of adjacent organs. In human non-small cell lung cancers, downregulation of the lung lineage-specifying TF NKX2-1 is associated with tumors bearing features of various gut tissues. Loss of Nkx2-1 from murine alveolar, but not airway, epithelium results in conversion of lung cells to gastric-like cells. Superimposing oncogenic Kras activation enables further plasticity in both alveolar and airway epithelium, producing tumors that adopt midgut and hindgut fates. Conversely, coupling Nkx2-1 loss with foregut lineage-specifying SOX2 overexpression drives the formation of squamous cancers with features of esophageal differentiation. These findings demonstrate that elements of pathologic tumor plasticity mirror the normal developmental history of organs in that cancer cells acquire cell fates associated with developmentally related neighboring organs.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Edward E. Morrisey
Basal cells are an important stem cell lineage in many tissues, including the lung. In this issue of Developmental Cell, Yang et. al. (2018) find that basal cells emerge very early in lung development and that a subset of these contributes to the expansive epithelial wound response observed after influenza injury.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Zhigang Xie, Seong Kwon Hur, Liang Zhao, Charles S. Abrams, Vytas A. Bankaitis
Phosphatidylinositol (PtdIns) transfer proteins (PITPs) stimulate PtdIns-4-P synthesis and signaling in eukaryotic cells, but to what biological outcomes such signaling circuits are coupled remains unclear. Herein, we show that two highly related StART-like PITPs, PITPNA and PITPNB, act in a redundant fashion to support development of the embryonic mammalian neocortex. PITPNA/PITPNB do so by driving PtdIns-4-P-dependent recruitment of GOLPH3, and likely ceramide transfer protein (CERT), to Golgi membranes with GOLPH3 recruitment serving to promote MYO18A- and F-actin-directed loading of the Golgi network to apical processes of neural stem cells (NSCs). We propose the primary role for PITP/PtdIns-4-P/GOLPH3/CERT signaling in NSC Golgi is not in regulating bulk membrane trafficking but in optimizing apically directed membrane trafficking and/or apical membrane signaling during neurogenesis.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Fumiaki Obata, Kayoko Tsuda-Sakurai, Takahiro Yamazaki, Ryo Nishio, Kei Nishimura, Masaki Kimura, Masabumi Funakoshi, Masayuki Miura
The intestine has direct contact with nutritional information. The mechanisms by which particular dietary molecules affect intestinal homeostasis are not fully understood. In this study, we identified S-adenosylmethionine (SAM), a universal methyl donor synthesized from dietary methionine, as a critical molecule that regulates stem cell division in Drosophila midgut. Depletion of either dietary methionine or SAM synthesis reduces division rate of intestinal stem cells. Genetic screening for putative SAM-dependent methyltransferases has identified protein synthesis as a regulator of the stem cells, partially through a unique diphthamide modification on eukaryotic elongation factor 2. In contrast, SAM in nutrient-absorptive enterocytes controls the interleukin-6-like protein Unpaired 3, which is required for rapid division of the stem cells after refeeding. Our study sheds light upon a link between diet and intestinal homeostasis and highlights the key metabolite SAM as a mediator of cell-type-specific starvation response.
Publication date: 26 March 2018
Source:Developmental Cell, Volume 44, Issue 6
Author(s): Ying Yang, Paul Riccio, Michael Schotsaert, Munemasa Mori, Jining Lu, Dong-Kee Lee, Adolfo García-Sastre, Jianming Xu, Wellington V. Cardoso
Basal cells (BCs) are p63-expressing multipotent progenitors of skin, tracheoesophageal and urinary tracts. p63 is abundant in developing airways; however, it remains largely unclear how embryonic p63+ cells contribute to the developing and postnatal respiratory tract epithelium, and ultimately how they relate to adult BCs. Using lineage-tracing and functional approaches in vivo, we show that p63+ cells arising from the lung primordium are initially multipotent progenitors of airway and alveolar lineages but later become restricted proximally to generate the tracheal adult stem cell pool. In intrapulmonary airways, these cells are maintained immature to adulthood in bronchi, establishing a rare p63+Krt5− progenitor cell population that responds to H1N1 virus-induced severe injury. Intriguingly, this pool includes a CC10 lineage-labeled p63+Krt5− cell subpopulation required for a full H1N1-response. These data elucidate key aspects in the establishment of regionally distinct adult stem cell pools in the respiratory system, potentially with relevance to other organs.
Ramucirumab—alone or combined with paclitaxel—represents one of the main options for patients failing first-line treatment for advanced gastric cancer.
The RAMoss study aimed to evaluate the safety and efficacy profile of ramucirumab in the "real-life setting".
Patients from 25 Italian hospitals started therapy consisting of ramucirumab 8 mg/kg i.v. d1,15q28 with or without paclitaxel 80 mg/m2 i.v. d1,8,15q28. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS).
One hundred sixty-seven patients with disease progression on first-line therapy received ramucirumab as monotherapy (10%) or combined with paclitaxel (90%). Median treatment duration was 4 months (1–17 months). Global incidence of grade (G) 3–4 toxicity was 9.6%, and for neutropenia 5.4%; treatment was discontinued due to toxicity in 3% of patients. The most frequent adverse events (AE) were G1–2 fatigue (27.5%), G1–2 neuropathy (26.3%), and G1–2 neutropenia (14.9%). ORR was 20.2%. Stable disease was observed in 39.2% of patients, with a disease control rate of 59.4%. With a median follow-up of 11 months, median PFS was 4.3 months (95% confidence interval [CI] 4.1–4.7), whereas median OS was 8.0 months (95% CI: 7.09–8.9). In a multivariate analysis, ECOG performance status <1 or ≥1 (HR 1.13, 95% CI 1.0–1.27, p = 0.04) and the presence versus absence of peritoneal metastases (HR 1.57, 95% CI 1.63–2.39, p = 0.03) were independent poor prognostic factors.
These "real-life" efficacy data on ramucirumab treatment are in line with previous randomized trials. Ramucirumab is well tolerated in daily clinical practice.
Jervell and Lange-Nielsen syndrome (JLNS), a rare autosomal recessive congenital QT prolongation syndrome, is characterized by cardiac arrhythmias, syncopal episodes, and profound deafness. A cochlear implant (CI) for patients with JLNS is expected to result in hearing improvement. Sometimes, defibrillation is required if a patient experiences lethal arrhythmia. In this paper, we report a pediatric patient with JLNS who received defibrillation after CI surgery in his right ear at the age of 2 years.
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Significant disparities exist in asthma outcomes. Racial and ethnic minorities have lower controller medication adherence, which may contribute to differences in asthma morbidity between minority and non-minority groups. The objective of this review is to identify individual, patient-provider communication, and systems issues that contribute to this pattern of medication underuse and to discuss potential strategies for intervention.
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Key Messages – 18-02-0119
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The two-hundredth anniversary of K. F. Graefe's "Rhinoplasty", E. Zeis' naming of the specialty of plastic surgery in 1838, and the continuing discussion on what is plastic surgery have prompted this historical-conceptual review with an analytic semantic insight into the meaning of the word "plastic". A literature search has revealed that this term has a dual content composed of an artistic and a philosophic aspect. Progressive development of these two connotations can be traced from their birth in the ceramics and myths of the ancient Greece to their metamorphoses in the fine arts, science, and plasticity philosophy of our days.
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The use of light for its antidepressant action dates back to the beginnings of civilization. As early as 4700 years ago, Wong Tai mentioned the fluctuation of diseases with seasons, Hippocrates wrote on the interrelation between seasonal climates and mood (melancholia and mania) [1], and Aretaeus of Cappadocia prescribed, in the second century AD, that "Lethargics be laid in the light, and exposed to the rays of the sun, for the disease is gloom". While being reported for millennia, bright light therapy (BLT) in depression was not officially recognized until 30 years ago for treating the Seasonal Affective Disorder (SAD), which may affect both unipolar and bipolar disorders (BD) [2].
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Chronic insomnia is highly prevalent and associated with significant morbidity (i.e., confers risk for multiple psychiatric and medical disorders, such as depression and hypertension). Therefore, it is essential to identify factors that perpetuate this disorder. One candidate factor in the neurobiology of chronic insomnia is hypothalamic-pituitary-adrenal-axis dysregulation, and in particular, alterations in circadian cortisol rhythmicity. Cortisol secretory patterns, however, fluctuate with both a circadian and an ultradian rhythm (i.e., pulses every 60-120 minutes).
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There is a wealth of evidence to say that sleep impacts maternal health during pregnancy, however, little has been published on fetal health and maternal sleep. This scoping review summarises current literature on maternal sleep including sleep disordered breathing, sleep quality, sleep duration and supine sleep position, as these relate to fetal outcomes specifically birth weight, growth, preterm birth and stillbirth.An overall interpretation of the studies evaluated shows that events occurring during maternal sleep such as obstructive sleep apnea, sleep disruption and sleep position may have a negative effect on the fetus resulting in altered growth, gestational length and even death.
https://ift.tt/2pHpBRY
Shift workers often experience reduced sleep quality, duration and/or excessive sleepiness due to the imposed conflict between work and their circadian system. About 20-30% of shift workers experience prominent insomnia symptoms and excessive daytime sleepiness consistent with the circadian rhythm sleep disorder known as shift work disorder. Individual factors may influence this vulnerability to shift work disorder or sleep-related impairment associated with shift work. This paper was registered with Prospero and was conducted using recommended standards for systematic reviews and meta-analyses.
https://ift.tt/2DXhSn2
J reconstr Microsurg
DOI: 10.1055/s-0038-1636939
Introduction Free-flap outcomes in lower extremity reconstruction carry the lowest anastomotic success rates compared with other anatomical sites. Despite their advantages over traditional nonperforator flaps, free perforator flaps have only recently become established in this area due to the additional challenges faced. It is therefore crucial to assess the anastomotic outcomes of perforator and nonperforator free flaps. Methods We performed a single-center retrospective cohort study and combined this with a meta-analysis of the relevant literature. We evaluated three flap anastomotic outcomes: reexploration, operative salvage, and flap failure rates. Results Between January 2010 and June 2015, our center managed 161 patients who underwent lower extremity free-flap reconstruction, which included 76 perforator flaps and 85 nonperforator flaps. The perforator flaps had higher reexploration rates compared with the nonperforator flaps, but this was not statistically significant (18.4 and 10.6%; p = 0.18). Perforator flaps had a higher flap salvage rate but were not statistically significant (78.6 and 22.2%; p = 0.374). Lastly, although not statistically significant, perforator flaps had a lower rate of complete failure due to anastomotic complications (3.9 and 8.2%; p = 0.336). The meta-analysis included 12 studies (inclusive of the index study) and found no statistical difference in all three outcomes. Conclusion Our meta-analysis is the first reported study and serves as an indication that free perforator flaps in lower extremity are as reliable as their traditional nonperforator counterparts. This does come with the prerequisite appreciation of the anatomical variations, the delicate handling of these flaps, and a low threshold for reexploration.
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Table of contents | Abstract | Full text
Melanoma of unknown primary (MUP) is incompletely described on a population level.
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Errors in Breslow thickness reporting can give misclassification of T category, an important classifier in melanoma staging.
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The risk of skin cancer in HIV-infected patients has not been extensively studied.
https://ift.tt/2pMK3Am
There are limited pediatric data on non-malignant cutaneous changes, including autoimmune conditions and permanent alopecia, after hematopoietic stem cell transplantation (HSCT).
https://ift.tt/2GenjQK
Humic acids have an important impact on the distribution, toxicity, and bioavailability of hazardous metals in the environment. In this study, a synthetic humic-like acid (SHLA) was prepared by an abiotic humification process using catechol and glycine as humic precursors and a MnO2 catalyst. The effect of physico-chemical conditions (ionic strength from 0.01 to 0.5 M NaNO3, pH from 4 to 8, temperature from 25 to 45 °C, and humic acid concentration from 5 to 100 mg/L) on the complexation ability of SHLA for Cu2+ were investigated. A commercial humic acid (CHA, CAS: 1415-93-6) from Sigma-Aldrich was also studied for comparison. The results showed that for pH 4 to 8, the conditional stability constants (log K) of SHLA and CHA were in the range 5.63–8.62 and 4.87–6.23, respectively, and complexation capacities (CC) were 1.34–2.61 and 1.42–2.31 mmol/g, respectively. The Cu complexation ability of SHLA was higher than that of the CHA due to its higher number of acidic functional groups (SHLA 19.19 mmol/g; CHA 3.87 mmol/g), extent of humification and aromaticity (AL/AR: 0.333 (SHLA); 1.554 (CHA)), and O-alkyl functional groups (SHLA 15.56%; CHA 3.45%). The log K and complexation efficiency (fraction of metal bound to SHLA) of SHLA were higher at higher pH, lower ionic strength, higher temperature, and higher SHLA concentration. Overall, SHLA was a good and promising complexation agent for copper in both soil washing of copper contaminated soil and the treatment of copper-containing wastewater.
Publication date: Available online 26 March 2018
Source:Free Radical Biology and Medicine
Author(s): Michael J. Maroney, Robert J. Hondal
This review highlights the contributions of Jean Chaudière to the field of selenium biochemistry. Chaudière was the first to recognize that one of the main reasons that selenium in the form of selenocysteine is used in proteins is due to the fact that it strongly resists permanent oxidation. The foundations for this important concept was laid down by Al Tappel in the 1960's and even before by others. The concept of oxygen tolerance first recognized in the study of glutathione peroxidase was further advanced and refined by those studying [NiFeSe]-hydrogenases, selenosubtilisin, and thioredoxin reductase. After 200 years of selenium research, work by Marcus Conrad and coworkers studying glutathione peroxidase-4 has provided definitive evidence for Chaudière's original hypothesis [Ingold, I., Berndt, C., Schmitt, S., Doll, S., Poschmann, G., Buday, K., Roveri, A., Peng, X., Porto Freitas, F., Seibt, T., Mehr, L., Aichler, M., Walch, A., Lamp, D., Jastroch, M., Miyamoto, S., Wurst, W., Ursini, F., Arnér, E. S. J., Fradejas-Villar, N., Schweizer, U., Zischka, H., Angeli J. P. F, and Conrad, M. (2018) Selenium utilization by GPX4 is required to prevent hydroperoxide-induced ferroptosis, Cell 172, 1–14.]. While the reaction of selenium with oxygen is readily reversible, there are many other examples of this phenomenon of reversibility. Many reactions of selenium can be described as "easy in – easy out". This is due to the strong nucleophilic character of selenium to attack electrophiles, but then this reaction can be reversed due to the strong electrophilic character of selenium and the weakness of the selenium-carbon bond. Several examples of this are described.
AbstractBackground
Few data exist on long-term outcomes and structural valve degeneration (SVD) in consecutive unselected patients undergoing surgical aortic valve replacement (SAVR).
ObjectivesThe goal of this study was to determine the long-term outcomes of a contemporary cohort of consecutive unselected SAVR recipients with a focus on evaluating clinical outcomes and SVD based on echocardiographic criteria.
MethodsA total of 672 consecutive patients (mean age: 72 ± 8 years; 61.5% male) undergoing SAVR with a bioprosthesis between 2002 and 2004 were included. Baseline and follow-up data were prospectively collected in a dedicated database. Baseline post-operative echocardiographic data were obtained in the 624 patients alive at hospital discharge and in 209 patients at 10 years (87% of the patients at risk). SVD was defined as subclinical (increase >10 mm Hg in mean transvalvular gradient + decrease >0.3 cm2 in valve area and/or new-onset mild or moderate aortic regurgitation) and clinically relevant (increase >20 mm Hg in mean transvalvular gradient + decrease >0.6 cm2 in valve area and/or new-onset moderate-to-severe aortic regurgitation).
ResultsAt a median follow-up of 10 years (interquartile range: 5 to 13 years), 432 patients (64.3%) had died. Older age, left ventricular dysfunction, atrial fibrillation, chronic obstructive pulmonary disease, greater body mass index, and diabetes mellitus were associated with an increased mortality risk (p < 0.05 for all). Clinically relevant SVD occurred in 6.6% of patients; 30.1% of patients had subclinical SVD. A greater body mass index and the use of a specific aortic bioprosthesis were independently associated with clinically relevant SVD (p < 0.05 for both), and 83% of these patients underwent aortic valve reintervention (valve-in-valve transcatheter aortic valve replacement in 44% of them).
ConclusionsThe 10-year mortality rate in elderly SAVR recipients of a bioprosthetic valve was considerable, chiefly determined by their older age and the presence of comorbidities. Clinically relevant SVD was infrequent, but close to one third of the population exhibited subclinical SVD. These results provide contemporary data on long-term clinical outcomes and SVD post-SAVR, and they should be taken into consideration when evaluating late clinical outcomes and valve durability after transcatheter aortic valve replacement.
Abstract
Most guidelines for the management of patients with cardiovascular disease recommend angiotensin-converting enzyme (ACE) inhibitors as first-choice therapy, whereas angiotensin receptor blockers (ARBs) are merely considered an alternative for ACE inhibitor–intolerant patients. The aim of this review was to compare outcomes and adverse events between ACE inhibitors and ARBs in patients. In patients with hypertension and hypertension with compelling indications, we found no difference in efficacy between ARBs and ACE inhibitors with regard to the surrogate endpoint of blood pressure and outcomes of all-cause mortality, cardiovascular mortality, myocardial infarction, heart failure, stroke, and end-stage renal disease. However, ACE inhibitors remain associated with cough and a very low risk of angioedema and fatalities. Overall withdrawal rates because of adverse events are lower with ARBs than with ACE inhibitors. Given the equal outcome efficacy but fewer adverse events with ARBs, risk-to-benefit analysis in aggregate indicates that at present there is little, if any, reason to use ACE inhibitors for the treatment of hypertension or its compelling indications.
AbstractBackground
Surgical aortic valve replacement using conventional biological valves (CBVs) is the standard of care for treatment of old patients with aortic valve disease. Recently, rapid deployment valves (RDVs) have been introduced.
ObjectivesThe purpose of this study was to report the nationwide German experience concerning RDVs for treatment of aortic valve stenosis and provide a head-to-head comparison with CBVs.
MethodsA total of 22,062 patients who underwent isolated surgical aortic valve replacement using CBV or RDV between 2011 and 2015 were enrolled into the German Aortic Valve Registry. Baseline, procedural, and in-hospital outcome parameters were analyzed for CBVs and RDVs using 1:1 propensity score matching. Furthermore, 3 RDVs were compared with each other.
ResultsA total of 20,937 patients received a CBV, whereas 1,125 patients were treated with an RDV. Patients treated with an RDV presented with significantly reduced procedure (160 min [25th to 75th percentile: 135 to 195 min] vs. 150 min [25th to 75th percentile: 127 to 179 min]; p < 0.001), cardiopulmonary bypass (83 min [25th to 75th percentile: 68 to 104 min] vs. 70 min [25th to 75th percentile: 56 to 87 min]; p < 0.001), and aortic cross clamp times (60 min [25th to 75th percentile: 48 to 75 min] vs. 44 min [25th to 75th percentile: 35 to 57 min]; p < 0.001), but showed significantly elevated rates of pacemaker implantation (3.7% vs. 8.8%; p < 0.001) and disabling stroke (0.9% vs. 2.2%; p < 0.001), whereas in-hospital mortality was similar (1.7% vs. 2.2%; p = 0.22). These findings persisted after 1:1 propensity score matching. Comparison of the 3 RDVs revealed statistically nonsignificant different pacemaker rates and significantly different post-operative transvalvular gradients.
ConclusionsIn this large, all-comers database, the incidence of pacemaker implantation and disabling stroke was higher with RDVs, whereas no beneficial effect on in-hospital mortality was seen. The 3 RDVs presented different complication profiles with regard to pacemaker implantation and transvalvular gradients. (German Aortic Valve Registry [GARY]; NCT01165827)
AbstractBackground
Presenting systolic blood pressure (SBP) is a powerful predictor of mortality in many cardiovascular settings, including acute coronary syndromes, cardiogenic shock, and acute heart failure.
ObjectivesThis study evaluated the association of presenting SBP with in-hospital outcomes, specifically all-cause mortality, in acute aortic dissection (AAD).
MethodsThe study included 6,238 consecutive patients (4,167 with type A and 2,071 with type B AAD) enrolled in the International Registry of Acute Aortic Dissection. Patients were stratified in 4 groups according to presenting SBP: SBP >150, SBP 101 to 150, SBP 81 to 100, or SBP ≤80 mm Hg.
ResultsThe relationship between presenting SBP and in-hospital mortality displayed a J-curve association, with significantly higher mortality rates in patients with very high SBP (26.3% for SBP >180 mm Hg in type A AAD, 13.3% for SBP >200 mm Hg in type B AAD; p = 0.005 and p = 0.018, respectively) as well as in those with SBP ≤100 mm Hg (29.9% in type A, 22.4% in type B; p = 0.033 and p = 0.015, respectively). This relationship was mainly from increased rates of in-hospital complications (acute renal failure, coma, and mesenteric ischemia/infarction in patients with SBP >150 mm Hg; stroke, coma, cardiac tamponade, myocardial ischemia/infarction, and acute renal failure in patients with SBP ≤80 mm Hg). Notably, presenting SBP ≤80 mm Hg was independently associated with in-hospital mortality in both type A (p = 0.001) and type B AAD (p = 0.003).
ConclusionsPresenting SBP showed a clear J-curve relationship with in-hospital mortality in patients with AAD. Although this association was related to increased rates of comorbid conditions at the edges of the curve, SBP ≤80 mm Hg was an independent correlate of in-hospital mortality.