Trastuzumab quantification in serum: a new,rapid, robust ELISA assay based on a mimetic peptide that specifically recognizes trastuzumab

Trastuzumab, a humanized monoclonal antibody directed against the epidermal growth factor receptor 2 (HER2), is a milestone in the treatment of HER2-overexpressing breast cancer patients. An enzyme-linked immunosorbent assay (ELISA) for trastuzumab has been developed for routine use in the laboratory to support clinical and pharmacokinetic studies to optimize therapy. The method relies on an antigen peptide linked to a 96-well plate via the streptavidin/biotin system. The peptide sequence mimics the extracellular portion of the HER2 receptor that is recognized by trastuzumab. The calibration range of the assay is 10 to 360 ng/mL per well, corresponding to a trastuzumab serum concentration from 5 to 180 μg/mL with a lower limit of quantification of 10 μg/mL. Validation results demonstrate that trastuzumab can be accurately and precisely quantified in human serum using this assay. The procedure was also tested in sera obtained from breast cancer patients to evaluate trastuzumab serum levels, confirming the applicability of method that could be a valid assay to use in daily laboratory practice.     

Rigid chain ribbon‐like metallopolymers

A set of new copolymers is here reported in which the repeating units are connected each other through Cu(II) metal centers. The coordination link is based on the bis‐chelating properties of salicylaldiminate groups of two different monomers. Due to their chemical structure, the two monomers afford, respectively, flexible and rigid repeating units in the metallocopolymers constitution upon coordination to copper centers. All the copolymers were soluble and easily processable. As shown by XRD analysis, rigid units' rich copolymers adopt a ribbon‐like structure in solid state in which highly planar strands of polymer stack thanks to π?π interactions, similarly to the polymer composed exclusively by rigid units. This behavior can be justified assuming the existence of a partial block character in copolymer constitution where long sequences of rigid units are alternated to sequences of flexible units. This assumption is supported also by DSC and UV–Vis analysis. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2412–2421     

An SPME–GC–MS method using an octadecyl silica fibre for the determination of the potential angiogenesis modulators 17β-estradiol and 2-methoxyestradiol in culture media

A simple and easily automable method based on solid-phase microextraction followed by gas chromatographic–mass spectrometric analysis was developed for the determination of two potential angiogenesis modulators 17β-estradiol (17-BE) and 2-methoxyestradiol (2-MEOE) in culture media. Trifluoroacetic anhydride was used as the derivatising agent. A homemade octadecyl silica coating, characterised by a coating thickness of 72 ± 10 μm and a good thermal stability until 250 °C, was prepared. Experimental design was used to optimise the extraction conditions in terms of derivatisation time, derivatisation temperature and time of extraction. As for method validation, lower limits of quantification of 0.17 and 0.015 μg/l for 17β-estradiol and 2-methoxyestradiol, respectively, were obtained. Finally, the capabilities of the developed fibres were evaluated for the analysis of the investigated analytes developed by granulosa cells in culture media maintained under normoxic, hypoxic and anoxic conditions, in order to better elucidate their possible role in the angiogenic process. An increase of the production of both 17-BE and 2-MEOE in hypoxic and anoxic conditions seems to be related to the effect of oxygen deprivation.     

Chemometric investigations on environmental data from Carlo Alberto irrigation canal (Alessandria,Piedmont, Italy)

The Carlo Alberto Canal connects Bormida and Tanaro rivers in Piedmont (ITALY). It was created for irrigation purposes but since its waters are suspected to be polluted, a sampling campaign was performed by the ARPA of Alessandria. The physico-chemical parameters analysed along 3 years (1998-2000) were investigated by multivariate chemometric methods. PCA showed that the waters situation depends heavily on the sampling period. Also a Kohonen self-organising map confirmed the clustering observed, providing insights into the causes of the clusterisation. New samplings are now being performed and a larger set of environmental variables is determined on each sample.     

Cannabioxepane, a novel tetracyclic cannabinoid from hemp, Cannabis sativa L.

Apart from large amounts of cannabidiol, the known stilbenoids 1-4 and the oxylipins 7 and 8, a fibre cultivar of Cannabis sativa derived from the historical Carmagnola variety gave the novel spiranic stilbenoid isocannabispiradienone (5) and the biphenyl-type cannabinoid cannabioxepane (CBX, 6), a tetracyclic compound characterized by an unprecedented C-5/C-8′ oxygen bridge and devoid of cannabinoid activity. Structures were established by analysis of MS and NMR data, and the biogenetic derivation of the new compounds is discussed.     

Determination of four thiophenethylamine designer drugs (2C‐T‐4, 2C‐T‐8, 2C‐T‐13, 2C‐T‐17) in human urine by capillary electrophoresis/mass spectrometry

An analytical procedure for the simultaneous determination in human urine of four thiophenethylamine designer drugs (2C‐T series) is reported. The quantitative analysis was performed by capillary electrophoresis with mass spectrometric detection (CE/MS), using 2,5‐dimethoxy‐4‐methylthiophenethylamine‐D₄ (2C‐T‐D₄) as internal standard. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid‐phase extraction (SPE) was introduced in the method as a clean‐up step. The method was validated according to international guidelines. The data for accuracy and precision were within required limits. Calibration curves were generated over the range from 10 to 500 ng mL^?1 and correlation coefficients always exceeded 0.997. The method was demonstrated to be specific, sensitive, and reliable for the analysis of these derivatives in urine samples. Copyright © 2010 John Wiley & Sons, Ltd.     

On the independence number of graphs related to a polarity

We investigate the independence number of two graphs constructed from a polarity of . For the first graph under consideration, the Erdős-Rényi graph , we provide an improvement on the known lower bounds on its independence number. In the second part of the paper, we consider the Erdős-Rényi hypergraph of triangles . We determine the exact magnitude of the independence number of , even. This solves a problem posed by Mubayi and Williford [On the independence number of the ErdŐs-RÉnyi and projective norm graphs and a related hypergraph, J. Graph Theory, 56 (2007), pp. 113-127, Open Problem 3].     

Antioxidant and spectroscopic studies of crosslinked polymers synthesized by grafting polymerization of ferulic acid

A novel, simple synthetic strategy for the preparation of crosslinked polymers with significant antioxidant properties is proposed. Ferulic acid (FA), a well‐known antioxidant compound, due to its reactivity toward free radical process, was inserted into a polymeric network with methacrylic acid (MAA) and ethylene glycole dimethacrylate acting as comonomer and crosslinker, respectively. All the reactants were simultaneously mixed in the polymerization feed and one‐pot radical reaction was carried out. Irregular microparticles were prepared by bulk polymerization and microspheres by precipitation polymerization. The materials were characterized by nuclear magnetic resonance–magic angle spinning (NMR‐MAS) studies, to verify effective FA insertion into polymeric networks, and by morphological, dimensional analyses, and water absorption measurement to study their superficial and swelling properties, respectively. Antioxidant properties of materials were evaluated by linoleic acid emulsion system–thiocyanate assay, determination of scavenging activity on DPPH radicals, determination of available phenolic groups in polymeric matrices, and determination of total antioxidant capacity. Copyright © 2009 John Wiley & Sons, Ltd.