Proximate Composition,Minerals and Antioxidant Activity of Artichoke Leaf Extracts

Biological Trace Element Research - In this study, leaf extracts from the Green Globe cultivar of artichoke (Cynara scolymus L.), a herbaceous plant of the Asteraceae family, were analyzed to...     

Conformation-activity relationships of cyclo-constrained micro/delta opioid agonists derived from the N-terminal tetrapeptide segment of dermorphin/deltorphin.

The N-terminal tetrapeptide segments of dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH(2)) and deltorphin (Tyr-D-Ala-Phe-Asp/Glu-Val-Val-Gly-NH(2)) are agonists at the opioid receptors micro and delta, respectively. [D-Arg(2), Lys(4)]-dermorphin-(1-4) amide (Tyr-D-Arg-Phe-Lys-NH(2), DALDA) and [Dmt(1)]DALDA (where Dmt is 2',6'-dimethyltyrosine) are among the most potent and selective micro-agonists reported to date, both in vitro (having picomolar micro receptor affinity) and in vivo. In this communication, conformation-activity studies of the following four cyclic analogs of DALDA are presented and discussed: the lead peptide S(2),S(4)-cyclo (Tyr-D-Cys-Phe-Cys-NH(2)), constrained by means of an S(4.2)--S(4.4) disulfide between Cys(2) and Cys(4); its two cis and trans C(4.2)--C(4.4)-olefinic dicarba analogs, and the product of saturation of them both. They are potent nonselective or moderately micro-selective opioid agonists in vitro.They have been synthesized and tested earlier [Berezowska I, Chung NN, Lemieux C, Wilkes BC, and Schiller PW, Acta Biochim Polon 53, 2006, 73-76]. We have studied their conformations using NMR and molecular dynamics. With major conformational constraints imposed by the 11-membered ring spanning residues 2-4, they show well defined conformations of this ring, while the exocylic Tyr(1) and Phe(3) side chains still have significant conformational freedom. The more active and selective micro versus delta disulfide and saturated dicarba agonists seem to have in common: (i) their ring structures more flexilble than those of the other two and (ii) their ring structures similar to each other and more diverse than those in the other two. Given this and the small size of the peptides having confirmed bioactivity profiles, there is a chance that their conformations determined in solution approach receptor-bound conformations. Copyright (c) 2008 European Peptide Society and John Wiley & Sons, Ltd.     

Can the condition of the cell microenvironment of mediastinal lymph nodes help predict the risk of metastases in non-small cell lung cancer?

Background: The aim of this study was to analyze the properties of the immune cell microenvironment of regional lymph nodes (LNs) positive for lung cancer. Methods: Twenty-four patients operated on for stages T1 and T2 of the NSCLC, were enrolled in the study. Peripheral blood and LN tissue were obtained from different lymph node sites and levels. As a control, LN tissue was taken from patients diagnosed with emphysema or pneumothorax. The cells from randomly chosen LN were tested by multi-color flow cytometry. Separate portions of LN were snap-frozen and examined for the presence of cytokeratin positive cells (CK). Propensity for apoptosis, level of TCR zeta chain expression of T cells and the number and maturation status of dendritic cells were confronted with the presence of CK-positive cells. Results: The presence of metastases correlated with the downregulation of TCR zeta, especially CD8(+) T cells. The most striking feature was the reduction in the number of myeloid CD11c(+) dendritic cells in the LN of patients with LN metastases. This could be a reflection of the immunodeficient state observed in lung cancer patients. Even in the absence of metastases in the regional LN, the same type of changes in the LN microenvironment were observed in those LN located nearer the primary tumor. Conclusions: The preliminary results of this study suggest that this approach may be helpful as an independent tumor staging factor. It is also worth noting that part of the staging process could also be based on features describing the immune cells in the peripheral blood.     

Feasibility of chiral discrimination using X-ray anomalous scattering

The paper discusses several feasibility prediction criteria with particular emphasis on light atom molecules. For several examples of refined absolute structures, feasibility predictions are calculated and compared with a posteriori calculated values of the Bijvoet ratio. An extension of the Pathasarathy table of the expected value of the Bijvoet ratio is given for parameter ranges corresponding to light anomalous scatters. Practical conclusions are drawn for absolute structure determination of compounds containing oxygen or nitrogen as anomalous scatterers. © 1993 Wiley-Liss, Inc.