Novel Substituted Purine Isosteres: Synthesis,Structure-Activity Relationships and Cytotoxic Activity Evaluation

A number of pyrrolo[2,3-c]pyridines, pyrrolo[3,2-d]pyrimidines and pyrazolo[4,3-d]pyrimidines were designed and synthesized as antiproliferative agents. The target compounds possessed selected substituents in analogous positions on the central scaffold that allowed the extraction of interesting SARs. The cytotoxic activity of the new derivatives was evaluated against prostatic (PC-3) and colon (HCT116) cell lines, and the most potent analogues showed IC₅₀ values in the nM to low µM range, while they were found to be non-toxic against normal human fibroblasts (WI-38). Flow cytometric analysis of DNA content revealed that the most promising derivative 14b caused a statistically significant accumulation of PC-3 cells at G₂/M phase and induced apoptosis in PC-3 cells.     

Organic-Inorganic Sol-Gel Hybrids with Ionic Properties

Summary.  A hybrid silicon precursor (ICS-PPG) obtained by reaction of 3-isocyanatopropyltriethoxy silane with poly-(propyleneglycol)-bis-(2-aminopropyl ether) was recognized as a potential host for various salts and molecular species. It has been used for electrochromic, gasochromic, photovoltaic, and fuel cell applications. This focuses on proton conducting gels (PWA/ICS-PPG, SiWA/ICS-PPG, and W-PTA/ICS-PPG) obtained after the incorporation of polyoxometalates in the ICS-PPG host. IR spectroscopic measurements are used to reveal the entrapment, the aggregation, and the interactions of W-PTA, PWA, or SiWA with the sol-gel derived network. The proton conductivity of the composites, measured using impedance spectroscopy, increases with increasing concentration of the polyoxometalates from 10⁻⁶ to 10⁻³ S/cm. Received June 23, 2000. Accepted (revised) September 18, 2000     

Studying Physiological Synchrony in Couple Therapy through Partial Directed Coherence: Associations with the Therapeutic Alliance and Meaning Construction

In line with the growing recognition of the role of embodiment, affect and implicit processes in psychotherapy, several recent studies examine the role of physiological synchrony in the process and outcome of psychotherapy. This study aims to introduce Partial Directed Coherence (PDC) as a novel approach to calculating psychophysiological synchrony and examine its potential to contribute to our understanding of the therapy process. The study adopts a single-case, mixed-method design and examines physiological synchrony in one-couple therapy in relation to the therapeutic alliance and a narrative analysis of meaning construction in the sessions. Interpersonal Physiological Synchrony (IPS) was calculated, via a windowed approach, through PDC of a Heart Rate Variability-derived physiological index, which was measured in the third and penultimate sessions. Our mixed-method analysis shows that PDC quantified significant moments of IPS within and across the sessions, modeling the characteristics of interpersonal interaction as well as the effects of therapy on the interactional dynamics. The findings of this study point to the complex interplay between explicit and implicit levels of interaction and the potential contribution of including physiological synchrony in the study of interactional processes in psychotherapy.     

Rosmarinus officinalis L. Leaf Extracts and Their Metabolites Inhibit the Aryl Hydrocarbon Receptor (AhR) Activation In Vitro and in Human Keratinocytes: Potential Impact on Inflammatory Skin Diseases and Skin Cancer

Aryl hydrocarbon receptor (AhR) activation by environmental agents and microbial metabolites is potentially implicated in a series of skin diseases. Hence, it would be very important to identify natural compounds that could inhibit the AhR activation by ligands of microbial origin as 6-formylindolo[3,2-b]carbazole (FICZ), indirubin (IND) and pityriazepin (PZ) or the prototype ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Five different dry Rosmarinus officinalis L. extracts (ROEs) were assayed for their activities as antagonists of AhR ligand binding with guinea pig cytosol in the presence of [³H]TCDD. The methanolic ROE was further assayed towards CYP1A1 mRNA induction using RT-PCR in human keratinocytes against TCDD, FICZ, PZ, and IND. The isolated metabolites, carnosic acid, carnosol, 7-O-methyl-epi-rosmanol, 4′,7-O-dimethylapigenin, and betulinic acid, were assayed for their agonist and antagonist activity in the presence and absence of TCDD using the gel retardation assay (GRA). All assayed ROE extracts showed similar dose-dependent activities with almost complete inhibition of AhR activation by TCDD at 100 ppm. The methanol ROE at 10 ppm showed 99%, 50%, 90%, and 85% inhibition against TCDD, FICZ, IND, and PZ, respectively, in human keratinocytes. Most assayed metabolites exhibited dose-dependent antagonist activity. ROEs inhibit AhR activation by TCDD and by the Malassezia metabolites FICZ, PZ, and IND. Hence, ROE could be useful for the prevention or treatment of skin diseases mediated by activation of AhR.     

Carbazolevinylene‐based polymers and model compounds with oxadiazole and triphenylamine segments: Synthesis,photophysics, and electroluminescence

Two new soluble alternating carbazolevinylene‐based polymers POXD and PTPA as well as the corresponding model compounds MOXD and MTPA were synthesized by Heck coupling. POXD and MOXD contained 2,5‐diphenyloxadiazole segments, while PTPA and MTPA contained triphenylamine segments. All samples displayed high thermal stability. The polymers had higher glass transition temperature (T_g) than their corresponding model compounds. The samples showed absorption maximum at 364–403 nm with optical band gap of 2.62–2.82 eV. They emitted blue‐green light with photoluminescence (PL) emission maximum at 450–501 nm and PL quantum yields in THF solution of 0.15–0.36. The absorption and the PL emission maxima of PTPA and MTPA were blue‐shifted as compared to those of POXD and MOXD . The electroluminescence (EL) spectra of multilayered devices made using four materials exhibited bluish green emissions, which is well consistent with PL spectra. The EL devices made using poly(vinyl carbazole) doped with MOXD and MTPA as emitting materials showed luminances of 12.1 and 4.8 cd m^?2. POXD and PTPA exhibited 25.4, and 96.3 cd m^?2, respectively. The polymer containing the corresponding molecules in the repeating group showed much higher device performances. Additionally, POXD and MOXD exhibited better stability of external quantum efficiency (EQE) and luminous efficiency with current density resulting from enhancing the electron transporting properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5592–5603, 2008     

Design and synthesis of some new pyranoxanthenones with cytotoxic activity

As part of a research program directed towards the design and synthesis of pyranoxanthones structurally related to acronycine, we present here the synthesis and cytotoxic activity of the pyranoxanthones 3 and 4 (X= H, Br; R= H, OMe; R'= H, Ac). Some of these compounds inhibit L1210 cell proliferation.     

Some attributes of cold hardiness of the gregarious ectoparasitoid Colpoclypeus florus (Hymenoptera: Eulophidae)

Cold hardiness of diapause and non-diapause larvae of the parasitoid Colpoclypeus florus Walker (Hymenoptera: Eulophidae) was examined in the laboratory. Mean supercooling point (SCP) for diapausing larvae was -26.7 degree C and for non-diapausing larvae immediately after their larval development, was -16.2 degree C. Mean SCP for non-diapause larvae at the prepupa stage was -19.1 degree C. A short period of acclimation (1 week at 5 degree C) had no influence on the mean SCPs of both diapause and non-diapause larvae. Pre-freeze mortality for diapause and non-diapause larvae was also studied. A constant exposure of diapause larvae to -6 degree C resulted in high mortality (70.7 percent) after a period of 40 days. In contrast, 6 days at -6 degree C were sufficient to cause the same level of mortality in non-diapause larvae. After exposure of 15 days at -9 degree C, mortality for non-diapause larvae was 70 percent, whereas after 20 days at the same temperature mortality of diapause larvae was 25 percent. The importance of these findings for the cryobiology of C. florus is discussed.     

Collagen fibril diameter in relation to bone site. a quantitative ultrastructural study

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of rats using electron microscopy analysis. Statistically significant differences (0.001<p<0.04) in mean fibril diameter values between different bone sites were detected demonstrating a dependence upon bone use.     

Addendum to: “Dissipative and Entropy Solutions to Non-Isotropic Degenerate Parabolic Balance Laws”

This note generalizes the notion of dissipative solutions to non-isotropic degenerate parabolic balance laws introduced in [3]. The new definition allows us to use a larger class of test functions than the one used in [3] to study the equivalence between dissipative and entropy solutions. As a result, it is possible to study general relaxation-type approximations (limits).Arch. Rational Mech. Anal. 170 (2003) 359–370 Digital Object Identifier (DOI) 10.1007/s00205-003-0282-5 Published online September 30, 2003Acknowledgement This work was partially supported by HYKE programme HPRN-CT-2002-00282 (http://www.hyke.org), and PANAGIOTIS E. SOUGANIDIS by the National Science Foundation.