<Emphasis Type="Italic">Jurinea turcica</Emphasis> (Asteraceae), a new species from North-West Anatolia,Turkey

Jurinea turcica B.Doǧan & A.Duran sp. nova (Asteraceae) is described and illustrated from North-West Anatolia, Turkey. It is closely related to J. macrocalathia and also an endemic. Diagnostic morphological characters of J. turcica from closely similar taxa are discussed. The pollen characteristics and achene surface morphology of J. turcica and J. macrocalathia are examined by SEM. It is diploid with the chromosome number of 2n = 34.     

HAT: Hypergeometric Analysis of Tiling-arrays with application to promoter-GeneChip data

Background  

Tiling-arrays are applicable to multiple types of biological research questions. Due to its advantages (high sensitivity, resolution, unbiased), the technology is often employed in genome-wide investigations. A major challenge in the analysis of tiling-array data is to define regions-of-interest, i.e., contiguous probes with increased signal intensity (as a result of hybridization of labeled DNA) in a region. Currently, no standard criteria are available to define these regions-of-interest as there is no single probe intensity cut-off level, different regions-of-interest can contain various numbers of probes, and can vary in genomic width. Furthermore, the chromosomal distance between neighboring probes can vary across the genome among different arrays.     

Influence of Dangling Ends and Surface-Proximal Tails of Targets on Probe-Target Duplex Formation in 16S rRNA Gene-Based Diagnostic Arrays

Dangling ends and surface-proximal tails of gene targets influence probe-target duplex formation and affect the signal intensity of probes on diagnostic microarrays. This phenomenon was evaluated using an oligonucleotide microarray containing 18-mer probes corresponding to the 16S rRNA genes of 10 waterborne pathogens and a number of synthetic and PCR-amplified gene targets. Signal intensities for Klenow/random primer-labeled 16S rRNA gene targets were dissimilar from those for 45-mer synthetic targets for nearly 73% of the probes tested. Klenow/random primer-labeled targets resulted in an interaction with a complex mixture of 16S rRNA genes (used as the background) 3.7 times higher than the interaction of 45-mer targets with the same mixture. A 7-base-long dangling end sequence with perfect homology to another single-stranded background DNA sequence was sufficient to produce a cross-hybridization signal that was as strong as the signal obtained by the probe-target duplex itself. Gibbs free energy between the target and a well-defined background was found to be a better indicator of hybridization signal intensity than the sequence or length of the dangling end alone. The dangling end (Gibbs free energy of −7.6 kcal/mol) was found to be significantly more prone to target-background interaction than the surface-proximal tail (Gibbs free energy of −64.5 kcal/mol). This study underlines the need for careful target preparation and evaluation of signal intensities for diagnostic arrays using 16S rRNA and other gene targets due to the potential for target interaction with a complex background.     

Digoxin Exhibits Neuroprotective Properties in a Rat Model of Dementia

Neurochemical Research - Alzheimer's disease (AD) is by far the most common cause of cognitive impairment in older adults. Current treatments are entirely focused on the symptoms of AD. A...     

Cytotoxic and Antimigratory Activity of Retrochalcones from Glycyrrhiza echinata L. on Human Cancer Cells

Cytotoxic activity-guided fractionation studies on Glycyrrhiza echinata roots led to the isolation of eight compounds ( 1 – 8 ). Chemical structures of the isolates were identified by NMR and MS analysis. Among the tested molecules, retrochalcones namely echinatin ( 3 ) (IC₅₀=23.45–41.83 μM), licochalcone B ( 4 ) (IC₅₀=36.04–39.53 μM) and tetrahydroxylmethoxychalcone ( 5 ) (IC₅₀=7.09–80.81 μM) were the most active ones against PC3, MCF7 and HepG2 cells. Moreover, 5 exhibited selectivity on prostate cancer cells (SI: 5.19). Hoechst staining and Annexin V/PI binding assays as well as cell cycle analysis on the compounds 3 (23 μM) and 5 (5 and 7 μM) demonstrated that these retrochalcones induced apoptosis and significantly suppressed cell cycle in G₁ and G₂/M phases. Furthermore, 3 and 5 showed antimigratory effects on PC3 cells by wound healing assay. The results indicated that tested retrochalcones most particularly 5 could be potential anticancer drug candidates that prevent proliferation and migration of cancer cells.