382 resultados para bioactivity


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NV1FGF is an expression plasmid encoding sp.FGF-1(21-154) currently under investigation for therapeutic angiogenesis in clinical trials. NV1FGF plasmid distribution and transgene expression following intramuscular (IM) injection in patients is unknown. The study involved six patients with chronic critical limb ischemia (CLI) planned to undergo amputation. A total dose of 0.5, 2, or 4 mg NV1FGF was administered as eight IM injections (0.006, 0.25, or 0.5 mg per injection) 3-5 days before amputation. Injected sites (30 cm(3)) were divided into equally sized smaller pieces to assess spatial distribution of NV1FGF sequences (PCR), NV1FGF mRNA (reverse transcriptase-PCR), and fibroblast growth factor-1 (FGF-1)-expressing cells (immunohistochemistry). Data indicated gene expression at all doses. The distribution area was within 5-12 cm for NV1FGF sequences containing the expression cassette, up to 5 cm for NV1FGF mRNA, and up to 3 cm for FGF-1-expressing myofibers. All FGF receptors were detected indicating robust potential for bioactivity after NV1FGF gene transfer. Circulating levels of NV1FGF sequences were shown to decrease within days after injection. Data support demonstration of plasmid-mediated gene transfer and expression in muscles from patients with CLI. FGF-1 expression was shown to be limited to injection sites, which supports the concept of multiple-site injection for therapeutic use.

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Ureides are compounds, which essentially incorporate urea as a substructural component either in open or cyclic form. Ureido derivatives are one of the oldest classes of bioactives, widely used as antiinfective agents. Several of these compounds, including aminoquinuride, aminocarbalide, imidurea, cloflucarban, nitrofurazone, urosulfan, viomycin are used in clinical situations. One of the ureides, the triclocarban is compulsorily used as antibacterial agent in cleansing and disinfecting solutions in hospital, household, cosmetics, toys, textile and plastics. It disables the activity of ENR, an enzyme vital for building the cell wall of the bacteria and fungus. Besides, the ureido-penicillins in clinical use there have been several ureido-lactam derivatives which have been reported to exhibit significant antibacterial activity. A urea containing dipeptide TAN-1057A isolated from Flexibacter spp. has potent bioactivity against MRSA. The metal complexes of sulphonyl ureido derivatives are effective antifungal agents by inhibiting the activity of phosphomannose isomerase, a key enzyme in the biosynthesis of yeast cell walls. There have been number of ureides including the cyclic ureas which are potent HIV protease inhibitors and display significant anti-HIV activity. The urea derivative, merimepodip that has been derived using structure based design, is potent inhibitor of IMPDH and is active against Hepatitis-C infection. This review will primarily focus on the significant work reported for this class of compounds including design, synthesis and biological activity.

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It is unknown how receptor binding by the paramyxovirus attachment proteins (HN, H, or G) triggers the fusion (F) protein to fuse with the plasma membrane for cell entry. H-proteins of the morbillivirus genus consist of a stalk ectodomain supporting a cuboidal head; physiological oligomers consist of non-covalent dimer-of-dimers. We report here the successful engineering of intermolecular disulfide bonds within the central region (residues 91-115) of the morbillivirus H-stalk; a sub-domain that also encompasses the putative F-contacting section (residues 111-118). Remarkably, several intersubunit crosslinks abrogated membrane fusion, but bioactivity was restored under reducing conditions. This phenotype extended equally to H proteins derived from virulent and attenuated morbillivirus strains and was independent of the nature of the contacted receptor. Our data reveal that the morbillivirus H-stalk domain is composed of four tightly-packed subunits. Upon receptor binding, these subunits structurally rearrange, possibly inducing conformational changes within the central region of the stalk, which, in turn, promote fusion. Given that the fundamental architecture appears conserved among paramyxovirus attachment protein stalk domains, we predict that these motions may act as a universal paramyxovirus F-triggering mechanism.

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OBJECTIVES The aim of this study was to forecast trends in restorative dentistry over the next 20 years and to identify treatment goals and corresponding properties of restorative materials. METHODS Using the Delphi method, a panel of 3 experts identified 8 key questions, which were sent to experts in restorative and preventive dentistry. In round 1 of this survey, 15 international experts devised a clearer semantic definition of the key questions and the completion of respective items for two additional rounds. In round 2, 125 experts from 35 countries rated the items developed in round 1 using a Likert scale. In round 3, the same 125 experts received the ratings of round 2 and were asked to agree or disagree to these ratings by re-voting on all key questions and items. A total of 105 experts re-voted and finally took part in the complete survey. Among the 8 key questions, two questions were selected for the present report: (Q1) "What will be the future role of restorative treatment?" and (Q6) "What will be the key qualities for clinical success of restorations?" For both questions and the respective items, the experts were asked to evaluate the importance and the feasibility for later calculation of the scientific value (i.e. the opportunity, where opportunity=importance+[importance-feasibility]). RESULTS The three items of highest importance for Q1 were "preservation of existing enamel and dentin tissue," "prevention of secondary caries," and "maintenance of the pulp vitality," and for Q6 they were "optimization of adhesion," "biocompatibility," and "minimizing technical sensitivity." SIGNIFICANCE Bioactivity toward the pulp-dentin complex and prevention of secondary caries were the items generally rated as having the highest opportunity.

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This study investigated the contribution of estrogen receptors (ERs) alpha and beta for epicardial coronary artery function, vascular NO bioactivity, and superoxide (O(2)(-)) formation. Porcine coronary rings were suspended in organ chambers and precontracted with prostaglandin F(2alpha) to determine direct effects of the selective ER agonists 4,4',4''-(4-propyl-[(1)H]pyrazole-1,3,5-triyl)tris-phenol (PPT) or 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) or the nonselective ER agonist 17beta-estradiol. Indirect effects on contractility to U46619 and relaxation to bradykinin were assessed and effects on NO, nitrite, and O(2)(-) formation were measured in cultured cells. Within 5 minutes, selective ERalpha activation by PPT, but not 17beta-estradiol or the ERbeta agonist DPN, caused rapid, NO-dependent, and endothelium-dependent relaxation (49+/-5%; P<0.001 versus ethanol). PPT also caused sustained endothelium- and NO-independent vasodilation similar to 17beta-estradiol after 60 minutes (72+/-3%; P<0.001 versus ethanol). DPN induced endothelium-dependent NO-independent relaxation via endothelium-dependent hyperpolarization (40+/-4%; P<0.01 versus ethanol). 17beta-Estradiol and PPT, but not DPN, attenuated the responses to U46619 and bradykinin. All of the ER agonists increased NO and nitrite formation in vascular endothelial but not smooth muscle cells and attenuated vascular smooth muscle cell O(2)(-) formation (P<0.001). ERalpha activation had the most potent effects on both nitrite formation and inhibiting O(2)(-) (P<0.05). These data demonstrate novel and differential mechanisms by which ERalpha and ERbeta activation control coronary artery vasoreactivity in males and females and regulate vascular NO and O(2)(-) formation. The findings indicate that coronary vascular effects of sex hormones differ with regard to affinity to ERalpha and ERbeta, which will contribute to beneficial and adverse effects of hormone replacement therapy.

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Human GH has two disulfide bridges linking Cys-53 to Cys-165 and Cys-182 to Cys-189. Although absence of the first disulfide bridge has been shown to affect the bioactivity of GH in transgenic mice, little is known of the importance of this bridge in mediating the GH/GH-receptor (GHR) interaction in humans. However, we have identified a missense mutation (G705C) in the GH1 gene of a Serbian patient. This mutation was found in the homozygous state and leads to the absence of the disulfide bridge Cys-53 to Cys-165. To study the impact of this mutation in vitro, GHR binding and Janus kinase (Jak)2/signal transducer and activator of transcription (Stat)5 activation experiments were performed, in which it was observed that at physiological concentrations (3-50 ng/ml) both GHR binding and Jak2/Stat5 signaling pathway activation were significantly reduced in the mutant GH-C53S, compared with wild-type (wt)-GH. Higher concentrations (400 ng/ml) were required for this mutant to elicit responses similar to wt-GH. These results demonstrate that the absence of the disulfide bridge Cys-53 to Cys-165 affects the binding affinity of GH for the GHR and subsequently the potency of GH to activate the Jak2/Stat5 signaling pathway. In conclusion, we have demonstrated that GH-C53S is a bioinactive GH at the physiological range and that the disulfide bridge Cys-53 to Cys-163 is required for mediating the biological effects of GH.

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An increasing number of lipid mediators have been identified as key modulators of immunity. Among these is a family of glycolipids capable of cellular uptake, loading onto the MHC-like molecule CD1d and stimulation of NKT cells. NKT cells are particularly interesting because they bridge innate and adaptive immunity by coordinating the early events of dendritic cell maturation, recruitment of NK cells, CD4 and CD8 T cells, and B cells at the site of microbial injury. As such, their therapeutic manipulation could be of the greatest interest in vaccine design or active immunotherapy. However, the use of NKT cells as cellular adjuvant of immunity in the clinic will require a better knowledge of the pharmacology of lipid agonists in order to optimize their action and avoid potential unseen off-target effects. We have been studying extracellular transport and cellular uptake of NKT agonists for the past few years. This field is confronted to a very limited prior knowledge and a small set of usable tools. New technology must be put in place and adapted to answering basic immunology questions related to NKT cells. The intimate link between the pharmacology of glycolipids and lipid metabolism makes us believe that great variations of bioactivity could be seen in the general population when NKT agonists are used therapeutically.

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Clearance of allergic inflammatory cells from the lung through matrix metalloproteinases (MMPs) is necessary to prevent lethal asphyxiation, but mechanistic insight into this essential homeostatic process is lacking. In this study, we have used a proteomics approach to determine how MMPs promote egression of lung inflammatory cells through the airway. MMP2- and MMP9-dependent cleavage of individual Th2 chemokines modulated their chemotactic activity; however, the net effect of complementing bronchoalveolar lavage fluid of allergen-challenged MMP2(-/-)/MMP9(-/-) mice with active MMP2 and MMP9 was to markedly enhance its overall chemotactic activity. In the bronchoalveolar fluid of MMP2(-/-)/MMP9(-/-) allergic mice, we identified several chemotactic molecules that possessed putative MMP2 and MMP9 cleavage sites and were present as higher molecular mass species. In vitro cleavage assays and mass spectroscopy confirmed that three of the identified proteins, Ym1, S100A8, and S100A9, were substrates of MMP2, MMP9, or both. Function-blocking Abs to S100 proteins significantly altered allergic inflammatory cell migration into the alveolar space. Thus, an important effect of MMPs is to differentially modify chemotactic bioactivity through proteolytic processing of proteins present in the airway. These findings provide a molecular mechanism to explain the enhanced clearance of lung inflammatory cells through the airway and reveal a novel approach to target new therapies for asthma.

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Systemic immune activation, a major determinant of HIV disease progression, is the result of a complex interplay between viral replication, dysregulation of the immune system, and microbial translocation due to gut mucosal damage. While human genetic variants influencing HIV viral load have been identified, it is unknown to what extent the host genetic background contributes to inter-individual differences in other determinants of HIV pathogenesis like gut damage and microbial translocation. Using samples and data from 717 untreated participants in the Swiss HIV Cohort Study and a genome-wide association study design, we searched for human genetic determinants of plasma levels of intestinal fatty-acid binding protein (I-FABP/FABP2), a marker of gut damage, and of soluble sCD14 (sCD14), a marker of LPS bioactivity and microbial translocation. We also assessed the correlations between HIV viral load, sCD14 and I-FABP. While we found no genome-wide significant determinant of the tested plasma markers, we observed strong associations between sCD14 and both HIV viral load and I-FABP, shedding new light on the relationships between processes that drive progression of untreated HIV infection.

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PURPOSE To evaluate the safety, tolerability and bioactivity of ascending doses of MP0112, a designed ankyrin repeat protein (DARPin) that binds with high affinity to vascular endothelial growth factor-A (VEGF-A), in treatment-naive patients with exudative age-related macular degeneration (AMD). DESIGN Phase I/II, open-label, multicenter, dose-escalation study. METHODS Patients were to receive a single intravitreal injection of MP0112 at doses ranging from 0.04 to 3.6 mg and be monitored for 16 weeks for safety, efficacy, pharmacokinetics, and dose response. RESULTS Altogether, 32 patients received a single injection of MP0112. The maximum tolerated dose was 1.0 mg because of a case of endophthalmitis in the 2.0 mg cohort. Drug-related adverse events were reported by 13 (41%) of 32 patients; they included ocular inflammation in 11 patients (7 mild, 4 moderate in severity). Visual acuity scores were stable or improved compared with baseline for ≥4 weeks following injection; both retinal thickness and fluorescein angiography leakage decreased in a dose-dependent manner. Rescue therapy was administered to 20 (91%) of 22 patients who received 0.04-0.4 mg MP0112 compared with 4 of 10 (40%) patients who received 1.0 or 2.0 mg. Of patients in the higher-dose cohorts who did not require rescue treatment, 83% (5/6) maintained reductions in central retinal thickness through week 16. CONCLUSIONS A single injection of 1.0 or 2.0 mg MP0112 resulted in mean decreases in retinal thickness and leakage area despite ocular inflammation. Larger-scale studies are warranted to confirm these observations.

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The hemagglutinin (H) gene of canine distemper virus (CDV) encodes the receptor-binding protein. This protein, together with the fusion (F) protein, is pivotal for infectivity since it contributes to the fusion of the viral envelope with the host cell membrane. Of the two receptors currently known for CDV (nectin-4 and the signaling lymphocyte activation molecule [SLAM]), SLAM is considered the most relevant for host susceptibility. To investigate how evolution might have impacted the host-CDV interaction, we examined the functional properties of a series of missense single nucleotide polymorphisms (SNPs) naturally accumulating within the H-gene sequences during the transition between two distinct but related strains. The two strains, a wild-type strain and a consensus strain, were part of a single continental outbreak in European wildlife and occurred in distinct geographical areas 2 years apart. The deduced amino acid sequence of the two H genes differed at 5 residues. A panel of mutants carrying all the combinations of the SNPs was obtained by site-directed mutagenesis. The selected mutant, wild type, and consensus H proteins were functionally evaluated according to their surface expression, SLAM binding, fusion protein interaction, and cell fusion efficiencies. The results highlight that the most detrimental functional effects are associated with specific sets of SNPs. Strikingly, an efficient compensational system driven by additional SNPs appears to come into play, virtually neutralizing the negative functional effects. This system seems to contribute to the maintenance of the tightly regulated function of the H-gene-encoded attachment protein. Importance: To investigate how evolution might have impacted the host-canine distemper virus (CDV) interaction, we examined the functional properties of naturally occurring single nucleotide polymorphisms (SNPs) in the hemagglutinin gene of two related but distinct strains of CDV. The hemagglutinin gene encodes the attachment protein, which is pivotal for infection. Our results show that few SNPs have a relevant detrimental impact and they generally appear in specific combinations (molecular signatures). These drastic negative changes are neutralized by compensatory mutations, which contribute to maintenance of an overall constant bioactivity of the attachment protein. This compensational mechanism might reflect the reaction of the CDV machinery to the changes occurring in the virus following antigenic variations critical for virulence.

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Indirect plant-mediated interactions between herbivores are important drivers of community composition in terrestrial ecosystems. Among the most striking examples are the strong indirect interactions between spatially separated leaf- and root-feeding insects sharing a host plant. Although leaf feeders generally reduce the performance of root herbivores, little is known about the underlying systemic changes in root physiology and the associated behavioral responses of the root feeders. We investigated the consequences of maize (Zea mays) leaf infestation by Spodoptera littoralis caterpillars for the root-feeding larvae of the beetle Diabrotica virgifera virgifera, a major pest of maize. D. virgifera strongly avoided leaf-infested plants by recognizing systemic changes in soluble root components. The avoidance response occurred within 12 h and was induced by real and mimicked herbivory, but not wounding alone. Roots of leaf-infested plants showed altered patterns in soluble free and soluble conjugated phenolic acids. Biochemical inhibition and genetic manipulation of phenolic acid biosynthesis led to a complete disappearance of the avoidance response of D. virgifera. Furthermore, bioactivity-guided fractionation revealed a direct link between the avoidance response of D. virgifera and changes in soluble conjugated phenolic acids in the roots of leaf-attacked plants. Our study provides a physiological mechanism for a behavioral pattern that explains the negative effect of leaf attack on a root-feeding insect. Furthermore, it opens up the possibility to control D. virgifera in the field by genetically mimicking leaf herbivore-induced changes in root phenylpropanoid patterns.

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Numerous insect herbivores can take up and store plant toxins as self-defense against their own natural enemies. Plant toxin sequestration is tightly linked with tolerance strategies that keep the toxins functional. Specific transporters have been identified that likely allow the herbivore to control the spatiotemporal dynamics of toxin accumulation. Certain herbivores furthermore possess specific enzymes to boost the bioactivity of the sequestered toxins. Ecologists have studied plant toxin sequestration for decades. The recently uncovered molecular mechanisms in combination with transient, non-transgenic systems to manipulate insect gene expression will help to understand the importance of toxin sequestration for food-web dynamics in nature.

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Environmental quality monitoring of water resources is challenged with providing the basis for safeguarding the environment against adverse biological effects of anthropogenic chemical contamination from diffuse and point sources. While current regulatory efforts focus on monitoring and assessing a few legacy chemicals, many more anthropogenic chemicals can be detected simultaneously in our aquatic resources. However, exposure to chemical mixtures does not necessarily translate into adverse biological effects nor clearly shows whether mitigation measures are needed. Thus, the question which mixtures are present and which have associated combined effects becomes central for defining adequate monitoring and assessment strategies. Here we describe the vision of the international, EU-funded project SOLUTIONS, where three routes are explored to link the occurrence of chemical mixtures at specific sites to the assessment of adverse biological combination effects. First of all, multi-residue target and non-target screening techniques covering a broader range of anticipated chemicals co-occurring in the environment are being developed. By improving sensitivity and detection limits for known bioactive compounds of concern, new analytical chemistry data for multiple components can be obtained and used to characterise priority mixtures. This information on chemical occurrence will be used to predict mixture toxicity and to derive combined effect estimates suitable for advancing environmental quality standards. Secondly, bioanalytical tools will be explored to provide aggregate bioactivity measures integrating all components that produce common (adverse) outcomes even for mixtures of varying compositions. The ambition is to provide comprehensive arrays of effect-based tools and trait-based field observations that link multiple chemical exposures to various environmental protection goals more directly and to provide improved in situ observations for impact assessment of mixtures. Thirdly, effect-directed analysis (EDA) will be applied to identify major drivers of mixture toxicity. Refinements of EDA include the use of statistical approaches with monitoring information for guidance of experimental EDA studies. These three approaches will be explored using case studies at the Danube and Rhine river basins as well as rivers of the Iberian Peninsula. The synthesis of findings will be organised to provide guidance for future solution-oriented environmental monitoring and explore more systematic ways to assess mixture exposures and combination effects in future water quality monitoring.

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BACKGROUND Recombinant bone morphogenetic protein two (rhBMP2) has been utilised for a variety of clinical applications in orthopaedic surgery and dental procedures. Despite its widespread use, concerns have been raised regarding its short half-life and transient bioactivity in vivo. Recent investigation aimed at developing rhBMP2 synthesized from a shorter polypeptide chain (108 amino acids) has been undertaken. METHODS The osteopromotive properties of BMP2 were investigated on cell behaviour. Five concentrations of rhBMP2_108 including 10, 50, 100, 200 and 500 ng/ml were compared to a commercially available rhBMP2 (100 ng/ml). Each of the working concentrations of rhBMP2_108 were investigated on MC3T3-E1 osteoblasts for their ability to induce osteoblast recruitment, proliferation and differentiation as assessed by alkaline phosphatase (ALP) staining, alizarin red staining, and real-time PCR for genes encoding ALP, osteocalcin (OCN), collagen-1 (COL-1) and Runx2. RESULTS The results demonstrate that all concentrations of rhBMP2_108 significantly improved cell recruitment and proliferation of osteoblasts at 5 days post seeding. Furthermore, rhBMP2_108 had the most pronounced effects on osteoblast differentiation. It was found that rhBMP2_108 had over a four fold significant increase in ALP activity at seven and 14 days post-seeding and the concentrations ranging from 50 to 200 ng/ml demonstrated the most pronounced effects. Analysis of real-time PCR for genes encoding ALP, OCN, COL-1 and Runx2 further confirmed dose-dependant increases at 14 days post-seeding. Furthermore, alizarin red staining demonstrated a concentration dependant increase in staining at 14 days. CONCLUSION The results from the present study demonstrate that this shorter polypeptide chain of rhBMP2_108 is equally as bioactive as commercially available rhBMP2 for the recruitment of progenitor cells by facilitating their differentiation towards the osteoblast lineage. Future in vivo study are necessary to investigate its bioactivity.