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Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Sugar,Oligoamides: Bound-State Conformation and DNA Minor-Groove-Binding Description by TR-NOESY and Differential-Frequency Saturation-Transfer-Difference Experiments

CHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2008
Florence Souard
Abstract Selective-frequency saturation-transfer-difference (STD) spectra allow the description of complexes established between minor-groove binders and long tracts of calf thymus DNA (ct-DNA). Two sets of experiments with selective saturation of either the H1, or H4,/H5,/H5,, proton NMR regions of deoxyribose allow the description of the ligand residues close to the inner (H1,) and outer regions (H4,/H5,/H5,,) of the minor groove of double-helical DNA. A series of complexes of sugar,oligoamides (2,6) with ct-DNA have been studied by both TR-NOESY and STD experiments. The binding mode of the complexes is similar to that of netropsin (1) and allows us to define a general binding mode for this family of ligands, in which an NH rim points towards the internal area (inner region) and a CH3 rim points towards the external part (outer region) of the minor groove of DNA. Also by means of both TR-NOESY and STD experiments, a description of the asymmetric centers of the sugar residue close to the inner and outer regions of the groove has been achieved. These results confirm that the sugar is responsible for the differences previously found in binding energetics. [source]

Anti-epidermal growth factor receptor monoclonal antibodies in cancer therapy

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2009
E. Martinelli
Summary The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor involved in the proliferation and survival of cancer cells. EGFR is the first molecular target against which monoclonal antibodies (mAb) have been developed for cancer therapy. Here we review the mechanisms underlying the effects of EGFR-specific mAb in cancer therapy. The efficacy of EGFR-specific mAb in cancer occurs thanks to inhibition of EGFR-generated signalling; furthermore, the effects of antibodies on the immune system seem to play an important role in determining the overall anti-tumour response. In this review, attention is focused on cetuximab and panitumumab, two mAb introduced recently into clinical practice for treatment of metastatic colorectal and head and neck cancer which target the external part of EGFR. [source]

Semen cryopreservation in the Salmonidae and in the Northern pike

AQUACULTURE RESEARCH, Issue 3 2000
F. Lahnsteiner
The present paper summarizes the data on a semen cryopreservation method for the Salmonidae (Oncorhynchus mykiss, Salmo trutta f. lacustris, Salvelinus fontinalis, Salvelinus alpinus, Salmo trutta f. fario, Hucho hucho, Coregonus lavaretus, Thymallus thymallus) and for the Northern pike (Esox lucius) published during recent years. It describes (1) methods used for the determination of sperm viability; (2) the protective efficiency of substances specifically for protection of internal and external parts of cells and the process of extender development; (3) the freezing, thawing and fertilization conditions; and (4) the tolerable deviations from the freezing protocol for more easy application. Finally, biomarkers are reported that predict the suitability of semen for cryopreservation and the quality of frozen,thawed semen. [source]

Progress in rational methods of cryoprotection in macromolecular crystallography

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2010
Thomas Alcorn
Cryogenic cooling of macromolecular crystals is commonly used for X-ray data collection both to reduce crystal damage from radiation and to gather functional information by cryogenically trapping intermediates. However, the cooling process can damage the crystals. Limiting cooling-induced crystal damage often requires cryoprotection strategies, which can involve substantial screening of solution conditions and cooling protocols. Here, recent developments directed towards rational methods for cryoprotection are described. Crystal damage is described in the context of the temperature response of the crystal as a thermodynamic system. As such, the internal and external parts of the crystal typically have different cryoprotection requirements. A key physical parameter, the thermal contraction, of 26 different cryoprotective solutions was measured between 294 and 72,K. The range of contractions was 2,13%, with the more polar cryosolutions contracting less. The potential uses of these results in the development of cryocooling conditions, as well as recent developments in determining minimum cryosolution soaking times, are discussed. [source]