Search

Insulin-like growth factor-2 binding proteins (IGF2BPs) are oncogenic RNA-binding proteins, highly up-regulated in HCC, and were recently validated as direct targets of the tumour suppressor miR-1275. It is worth noting that around 47% of FDA approved anticancer drugs are derived from plants. Modulation by miRNAs and their cellular signalling cascades could constitute new pathways by which these phytochemicals exert their effects. This study aimed to investigate the potential use of Tamarix articulata, quercetin and epigallocatechin gallate (EGCG) in HCC and how these phytochemicals could epigenetically modulate the IGF axis using their impact on miR-1275. T. articulata ethyl acetate fraction significantly reduced the viability of Huh-7 cells compared to control cells. Treatment with T. articulata ethyl acetate fraction, quercetin and EGCG significantly enhanced miR-1275, while suppressed IGF2BP1 and IGF2BP3 mRNA expression levels. In summary, T. articulata, quercetin and EGCG have important implications for HCC molecular-targeted therapy through destabilizing the interplay between miR-1275 and the IGF axis. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mass Spectrometry is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We have investigated the fragmentation behavior of a number of DOTA-metal complexes under collision-induced dissociation, infrared-multiphoton dissociation and higher-energy collisional dissociation activation conditions. Both, positive and negative ion mode electrospray ionization was applied. The results show that characteristic fragmentations were obtained for the metalcomplexes under the investigated conditions. All elemental compositions of fragment ions have been unambiguously identified by high resolution-accurate mass measurements. Certain trends, for instance eliminations of carbon dioxide, alkyl and amine residues, were observed that coincidewith the size of themetal and its locationwithin the periodic table. Additionally, lanthanide, aluminium and indium species with even oxidation state or containing a radical have been detected. To further investigate the observed water capture during activation, deuterium labeling experiments have also been carried out. [ABSTRACT FROM AUTHOR]

Sensitive, accurate and fast absolute quantification of intact proteins is reported using metal coded affinity tags (MeCATs) combined with gel electrophoresis (GE) separation, inductively coupled plasma mass spectrometry (ICP-MS) detection and label-specific isotope dilution analysis quantification. Two different approaches were investigated concerning the introduction of the sample into ICP-MS, mineralization of the gel and direct laser ablation (LA) of the spot. Three major advantages are remarkable in the proposed method. First, not only heteroatom-containing proteins but also all labeled proteins in the sample can be absolutely quantified preparing an isotopically enriched tracer. On the other hand, highly sensitive determination in the amol range can be performed, considerably reducing the analysis time due to the straightforward measurements by ICP-MS. Furthermore, the studied method allows accurate quantifications with different sample-to-spike ratios and using stock spikes stored for months. After the first characterization using standard proteins, human serum albumin (HSA) and transferrin (Tf) were determined in human serum to test the applicability of the method to biological samples. The results show satisfactory quantifications for the studied proteins despite the difference in concentration and the similarity in migration distances. [ABSTRACT FROM AUTHOR]

Aims To directly compare the differential effects of oxygen, prostacyclin and iloprost (aerosolized and intravenous) in primary pulmonary hypertension.Methods and results Twenty-one patients with severe primary pulmonary hypertension underwent right heart catheterization following oxygen inhalation, inhalation of aerosolized iloprost, intravenous prostacyclin or intravenous iloprost. The stability of the iloprost solution was tested for up to 4 weeks. Oxygen slightly decreased pulmonary vascular resistance. Intravenous prostacyclin (7.2±3.4ngkg−1min−1) reduced pulmonary (1772±844 vs 1325±615dynscm−5, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.001\) \end{document}) and systemic vascular resistance, and arterial and right atrial pressure, while cardiac output increased. Iloprost inhalation diminished pulmonary (1813±827 vs 1323±614dynscm−5, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.001\) \end{document}) and systemic vascular resistance, and pulmonary artery (58±12 vs 50±12mmHg,\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.001\) \end{document}) and right atrial pressure, while cardiac output increased. With intravenous iloprost (1.2±0.5ngkg−1min−1, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=8\) \end{document}) a decrease in pulmonary (2202±529 vs 1515±356dynscm−5, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.05\) \end{document}) and systemic vascular resistance and right atrialpressure occurred while cardiac output increased. Iloprost solution remained stable for 33 days while losing <10% (4°C) of its active drug concentration.Conclusions Intravenous iloprost and prostacyclin have very similar haemodynamic profiles. In contrast, only inhaled iloprost exerted selective pulmonary vasodilation, reducing pulmonary vascular resistance and pulmonary artery pressure withoutsystemic vasodilation. The longer half-life and extended stability despite lower costs render iloprost an attractive alternative to chronic prostacyclin treatment in primary pulmonary hypertension. [ABSTRACT FROM PUBLISHER]

For application of continuous-flow fast atom bombardment (CFFAB), an ion source for a sector field mass spectrometer was designed which gives improved sensitivity and much better long-term stability than a source with standard ion optics. The optics are based on two sets of static quadrupoles and a conical ion extraction device. It was shown that the gain in sensitivity has to be assigned mainly to the reduction of the chemical background in the CFFAB mass spectra. The reason for this reduction appears to be the exclusion of matrix fragment ions sputtered from the outer parts of the FAB target, whereas the center is continuously refreshed by the liquid emerging the capillary. The benefits of using this source were demonstrated in the course of the determination of the drug ifosfamide to a level of 1.5 ng cm−3 using selected ion recording and in the analysis of a Gramicidin S sample, where a minor component at a level of ∼1 pmol was detected. [ABSTRACT FROM AUTHOR]

A new and simple ion source for thermospray on a sector field mass spectrometer has been designed, which is based on two sets of electrostatic quadrupole lenses to focus the divergent ion beam that emanates from the extraction cone into the ion source region. To illustrate the performance of the source, the on-line separation and detection of a few samples are shown using scanning and single-ion monitoring techniques. Examples are a mixture of phena-zines and samples of caffeine and adenosine. With single ion motoring, 5 ng of a phenazine, 300 pg of caffeine and ∼1 ng of adenosine were detected. Further, it is shown that declustering and collision-induced fragmentation occur inside the sampling cone, resulting in peak broadening on the low-mass side of signals of protonated species. Minimizing the collision-induced dissociation of erythromycin was used to optimize the flow-rate of the liquid chromatograph and the pressure in the source housing. [ABSTRACT FROM AUTHOR]

Copyright of Organic Mass Spectrometry is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The collisionally activated dissociation (CAD) of six protonated dinucleoside monophosphates produced by field desorption has been studied by linked scanning ( B/E=constant). Complete spectra with detailed structure information have been obtained despite the small ion currents and other technical problems. It is possible to distinguish isomeric sequences in both ribo- and deoxyribo-nucleotides series. [ABSTRACT FROM AUTHOR]

Phenolic metabolite profiling using two dimensional paper chromatographic analysis (2 DPC) was used for assaying the complex mixture of phenolics of an aqueous ethanol aerial part extract of Cuphea ignea (Lytheraceae). A coumarin with a rare structure, namely, 7-hydroxy 3-methoxy coumarin 5-O-β-glucopyranoside was isolated from the investigated extract. The structure was elucidated by conventional methods and spectral analysis, including one and two dimensional NMR (1D and 2D NMR), as well as by interpretation of the spectra obtained by high resolution electrospray ionization mass technique (HRESIMS). The rare coumarin significantly inhibited reactive oxygen species production with an ED50 value of 6.31±1.64 μg/ml and 5.78±0.66 μg/ml as determined by the the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the oxygen radical absorption capacity (ORAC) assay respectively. The isolated coumarin presented a cytotoxic activity assessed by using the neutral red assay (NRU) against lung cancer cell line (H23) with IC50 of 40.38±2.75 μg/ml.

Leaves of Melaleuca leucadendra contain the novel flavonol glycoside, myricetin 3-O-β-4C1-galactopyranuronoid. In addition, known fifteen phenolics were identified. All isolates are characterized for the first time from this plant. Structures were established by conventional methods and confirmed by spectral methods of analysis, including one and two-dimensional nuclear magnetic resonance spectroscopy (1D and 2D-NMR) and high resolution electro-spray ionization mass spectrometry (HRESIMS), as well. Assessment of some immunological and biological efficacy, of the extract in combination with a parallel cytotoxicity evaluation, using the method of cellular reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) technique was carried out. Besides, evaluation of the antioxidant effectiveness, using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the oxygen radical absorption capacity (ORAC) methods was performed. In addition, the cytotoxicity against liver (Huh-7), breast (MCF-7) and prostate (PC-3) cancers using the neutral red assay (NRU) technique for the extract and the new flavonol glycoside also, was assessed.

Bdellovibrio bacteriovorus is an obligate predator of bacteria that grows and divides within the periplasm of its prey. Functions involved in the early steps of predation have been identified and characterized, but mediators of prey invasion are still poorly detailed. By combining omics data available for Bdellovibrio and like organisms (BALO's), we identified 43 genes expressed in B. bacteriovorus during the early interaction with prey. These included genes in a tight adherence (TAD) operon encoding for two type IVb fimbriae-like pilin proteins (flp1 and flp2), and their processing and export machinery. Two additional flp genes (flp3 and flp4) were computationally identified at other locations along the chromosome, defining the largest and most diverse type IVb complement known in bacteria to date. Only flp1, flp2 and flp4 were expressed; their respective gene knock-outs resulted in a complete loss of the predatory ability without losing the ability to adhere to prey cells. Additionally, we further demonstrate differential regulation of the flp genes as the TAD operon of BALOs with different predatory strategies is controlled by a flagellar sigma factor FliA, while flp4 is not. Finally, we show that FliA, a known flagellar transcriptional regulator in other bacteria, is an essential Bdellovibrio gene.

Phenolic metabolite profiling and identification using high performance liquid chromatography (HPLC) coupled to high resolution accurate mass spectrometry (HR-ESI-MS) with detection of negative ions was used for assaying the complex mixture of phenolics of an aqueous ethanol leaf extract of Eugeniajambos L. (Myrtaceae). Eight known polyphenolics were tentatively identified, and, in addition, three hitherto unknown flavonol-O-glycosides were detected in the extract. These unknowns were taken as the targets and isolated by means of consecutive polyamide S6, MCI gel and repeated Sephadex LH-20 column fractionation. The isolation and purification were monitored by HPLC/ESI-MS. The isolates were subsequently identified as quercetin 3-O-xylosyl-(1"' --> 2")-O-xyloside, myricetin 7-methylether 3-O-xylosyl-(1"' --> 2")-rhamnoside and myricetin 3',5'-dimethyl ether 3-O-xylosyl-(1"'-->* 2")-O-rhamnoside. All known metabolites were also separated by applying the same chromatographic techniques. ESI-MS, ¹H and ¹³C NMR spectra were then recorded, completely interpreted and confirmed by HR-ESI-MS and 2D NMR spectroscopy. In order to get information about biological activities of E. jambos the extract was tested for radical scavenging activity by DPPH and ORAC assay. In addition, its cytotoxicity was assessed by the neutral red assay against non-tumorigenic HaCaT keratinocytes and the human bladder carcinoma cell line 5637.

Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(α,β)-4C1-glucopyranose (8), for which 1D and 2D-NMR spectra were recorded and assigned for the first time. The structures of all isolates (1 - 8) were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HR-ESIMS as well. All of the isolated compounds were evaluated for their antioxidant activities, determined by the DPPH and ORAC methods and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis. Compounds 1, 3, 4, 5, and 6 significantly inhibited reactive oxygen species production with ED50 values between 3.22 and 9.79 μg/ml. Compounds 1, 3, 4, and 5 showed cytotoxic activity against HaCaT cells with IC50 values between 30.7 and 84.1 μg/ml. The new galloyl glucose (8) was found not cytotoxic. Ellagitannins, 2,3-hexahydroxy-((α/β)-glucopyranose (1) and 1 -0-galloyl 2,3-hexahydroxy-(α)-glucopyranose (5) possess remarkable antioxidative and comparably weak cytotoxic activity.