Identification of thieno[3,2-b]pyrroles as allosteric inhibitors of hepatitis C virus NS5B polymerase

Thieno[3,2-b]pyrroles are a novel class of allosteric inhibitors of HCV NS5B RNA-dependent RNA polymerase which show potent affinity for the NS5B enzyme. Introduction of a polar substituent in the position N1 led to a compound that efficiently blocks subgenomic HCV RNA replication in HUH-7 cells with an EC50 of 2.9 microM.     

Response of 1,2-dichloroethane-adapted microbial communities to ex-situ biostimulation of polluted groundwater

The microbial community of a groundwater system contaminated by 1,2-dichloroethane (1,2-DCA), a toxic and persistent chlorinated hydrocarbon, has been investigated for its response to biostimulation finalized to 1,2-DCA removal by reductive dehalogenation. The microbial population profile of samples from different wells in the aquifer and from microcosms enriched in the laboratory with different organic electron donors was analyzed by ARISA (Amplified Ribosomal Intergenic Spacer Analysis) and DGGE (Denaturing Gradient Gel Electrophoresis) of 16S rRNA genes. 1,2-DCA was completely removed with release of ethene from most of the microcosms supplemented with lactate, acetate plus formate, while cheese whey supported 1,2-DCA dehalogenation only after a lag period. Microbial species richness deduced from ARISA profiles of the microbial community before and after electron donor amendments indicated that the response of the community to biostimulation was heterogeneous and depended on the well from which groundwater was sampled. Sequencing of 16S rRNA genes separated by DGGE indicated the presence of bacteria previously associated with soils and groundwater polluted by halogenated hydrocarbons or present in consortia active in the removal of these compounds. A PCR assay specific for Desulfitobacterium sp. showed the enrichment of this genus in some of the microcosms. The dehalogenation potential of the microbial community was confirmed by the amplification of dehalogenase-related sequences from the most active microcosms. Cloning and sequencing of PCR products indicated the presence in the metagenome of the bacterial community of a new dehalogenase potentially involved in 1,2-DCA reductive dechlorination.     

Cross-modal interactions between olfaction and vision when grasping

This study used kinematics to investigate the integration between vision and olfaction during grasping movements. Participants were requested to smell an odorant and then grasp an object presented in central vision. The results indicate that if the target was small (e.g., a strawberry), the time and amplitude of maximum hand aperture were later and greater, respectively, when the odor evoked a larger object (e.g., an orange) than when the odor evoked an object of a similar size as the target or no odor was presented. Conversely, the time and amplitude of maximum hand aperture were earlier and reduced, respectively, when the target was large (e.g., a peach) and the odor evoked a smaller sized object (e.g., an almond) than when the odor evoked an object of a similar size as the target or no odor was presented. Taken together, these results support the evidence of cross-modal links between olfaction and vision and extend this notion to goal-directed actions.     

Osteogenic growth peptide effects on primary human osteoblast cultures: potential relevance for the treatment of glucocorticoid-induced osteoporosis

The osteogenic growth peptide (OGP) is a naturally occurring tetradecapeptide that has attracted considerable clinical interest as a bone anabolic agent and hematopoietic stimulator. In vivo studies on animals have demonstrated that the synthetic peptide OGP (10-14), reproducing the OGP C-terminal active portion [H-Tyr-Gly-Phe-Gly-Gly-OH] increases bone formation, trabecular bone density and fracture healing. In vitro studies performed on cellular systems based on osteoblastic-like cell lines or mouse stromal cells, have demonstrated that OGP (10-14) increases osteoblast proliferation, alkaline phosphatase (ALKP) activity and matrix synthesis and mineralization. In view of a potential application of OGP (10-14) in clinical therapy, we have tested different concentrations of OGP (10-14) on primary human osteoblast (hOB) cultures. We have observed significant increases of hOB proliferation (+35%), ALKP activity (+60%), osteocalcin secretion (+50%), and mineralized nodules formation (+49%). Our experimental model based on mature hOBs was used to investigate if OGP (10-14) could prevent the effects on bone loss induced by sustained glucocorticoid (GC) treatments. A strong decrease in bone formation has been attributed to the effects of GCs on osteoblastogenesis and osteocyte apoptosis, while an increase in bone resorption was due to a transient osteoblastic stimulation, mediated by the OPG/RANKL/RANK system, of osteoclasts recruitment and activation. Moreover, GCs act on hOBs decreasing the release of osteoprotegerin (OPG) a regulator of the RANKL/RANK interaction. Here, we provide evidences that OGP (10-14) inhibits hOB apoptosis induced by an excess of dexamethasone (-48% of apoptotic cells). Furthermore, we show that OGP (10-14) can increase OPG secretion (+20%) and can restore the altered expression of OPG induced by GCs to physiological levels. Our results support the employment of OGP (10-14) in clinical trials addressed to the treatment of different bone remodeling alterations including the GC-induced osteoporosis.     

White coat hypertension and haemostatic/fibrinolytic balance disorders

White coat hypertension (WCH) or isolated clinic hypertension is generally accepted to be a benign condition, although some reports have suggested that it may be associated with an increased cardiovascular event rate or other cardiovascular alterations. It has been previously shown that essential hypertension (EH) is associated with abnormalities in haemostatic/fibrinolytic balance and endothelial function. The aim of our study was to assess the impact of WCH on fibrinolytic balance and endothelial function by measuring plasma levels of plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (tPA), fibrinogen, and thrombomodulin. These markers were determined in 71 patients with EH, 26 with WCH and 87 normotensive healthy control subjects. The three groups were not different with respect to age, gender, smoking habits, BMI and blood lipids. Subjects with WCH were found to have increased plasma levels of PAI-1, tPA, fibrinogen and thrombomodulin compared to controls, but less compared to hypertensive ones. Our results suggest that WCH may be associated with decreased fibrinolytic potential and endothelial dysfunction, indicating that WCH may not be a completely harmless trait.     

Effects of olfactory stimuli on arm-reaching duration

The aim of the present study was to investigate the effects of olfactory stimuli on visually guided reaching. In Experiment 1, participants reached toward and grasped either a small (almond/strawberry) or a large (apple/orange) visual target. Any 1 of 4 odors corresponding to the visual stimuli or odorless air was administered before movement initiation. Within the same block of trials, participants smelled 1) an odor associated with an object of a different size than the target, 2) an odor associated with an object of a size equal to that of the target, or 3) odorless air. Results indicated that reaching duration was longer for trials in which the odor "size" and the visual target did not match than when they matched. In Experiment 2, the same procedures were applied but the "no-odor" trials were administered in a separate block to the "odor" trials. Similar results as for Experiment 1 were found. However, in contrast to Experiment 1, the presence of an odor increased the level of alertness resulting in a shortening of reaching duration. We contend that olfactory stimuli have the capacity to elicit motor plans interfering with those programmed for a movement toward a visual stimulus.     

Antimicrobial and cytotoxic arylazoenamines. Part III: antiviral activity of selected classes of arylazoenamines

Eighty-five arylazoenamines, characterized by different types of aryl and basic moieties, have been synthesized and evaluated in cell-based assays for cytotoxicity and antiviral activity against a panel of ten RNA and DNA viruses. The most commonly affected viruses were, in decreasing order, CVB-2, RSV, BVDV, YFV, and Sb-1; the remaining viruses were either not affected (HIV-1, VSV, and VV) or susceptible only to a very few compounds (Reo-1 and HSV-1). Thirty-five compounds exhibited high activity, with EC(50) in the range 0.8-10 microM, and other 28 compounds had EC(50) between 11 and 30 microM, thus indicating that the arylazoenamine molecular pattern is an interesting novel pharmacophore for antiviral agents against ssRNA viruses. Moreover, some compounds (as 28, 32, 42, and 53) appear of high interest, being devoid of toxicity on the human MT-4 cells (CC(50)>100 microM). A ligand-based computational approach was employed to identify highly predictive pharmacophore models for the most frequently affected viruses CVB-2, RSV, and BVDV. These models should allow the design of second generation of more potent inhibitors of these human and veterinary pathogens.     

The number and distances of positive charges of polyamine side chains in a series of perylene diimides significantly influence their ability to induce G-quadruplex structures and inhibit human telomerase

We have synthesized eight polyamine perylene diimides to conjugate the efficiency of perylene derivatives in stabilizing G-quadruplex structures and the polyamines' biological activity, due to specific interactions with different DNA domains. Our study was carried out by investigating the ability of these derivatives to induce inter- and intramolecular G-quadruplex structures by polyacrylamide gel electrophoresis (PAGE) and to inhibit telomerase in a modified TRAP assay. The two properties appear to be satisfactorily correlated and they show that the number and distances of positive charges in the side chains dramatically influence both these features. Although our previous studies on perylene derivatives with mono-positively charged side chains indicated that self assembly in aqueous solution leads to a major efficiency, the result observed with the spermine derivative suggests that a too strong aggregation is unfavourable, because it determines a lower solubility of the compounds.     

Cell volume regulation following hypotonic stress in the intestine of the eel, Anguilla anguilla, is Ca2+-dependent

The involvement of Ca2+ in the regulatory volume decrease (RVD) mechanism was studied in both isolated enterocytes and intestine of the eel, Anguilla anguilla. Videometric methods and electrophysiological techniques were respectively employed. The isolated enterocytes rapidly swelled following a change from isotonic (315 mOsm/kg) to hypotonic (180 mOsm/kg) saline solutions. Afterwards, they tended to recover their original size. This homeostatic response was inhibited both in the absence of extracellular Ca2+ and in the presence of TMB8, an inhibitor of Ca2+ release from intracellular stores. It is likely that Ca2+ entry through verapamil-sensitive Ca2+ channels is responsible for RVD since the blocker impaired the ability of the cell to recover its volume after the hypotonic shock. The observation that a 10-fold increase of K+ concentration as well as the presence of quinine in the hypotonic solution completely abolished RVD indicated the involvement of K+ in this response. Experiments performed with the isolated intestine suggested that the opening of basolateral K+ channels facilitates K+ loss (and hence water efflux) from the cell during RVD and that this opening is probably due to Ca2+ entry into the cell through both the mucosal and the serosal membranes.