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Sample records for biological properties issledovanie

  1. Antimicrobial Peptides: Versatile Biological Properties

    PubMed Central

    Pushpanathan, Muthuirulan; Rajendhran, Jeyaprakash

    2013-01-01

    Antimicrobial peptides are diverse group of biologically active molecules with multidimensional properties. In recent past, a wide variety of AMPs with diverse structures have been reported from different sources such as plants, animals, mammals, and microorganisms. The presence of unusual amino acids and structural motifs in AMPs confers unique structural properties to the peptide that attribute for their specific mode of action. The ability of these active AMPs to act as multifunctional effector molecules such as signalling molecule, immune modulators, mitogen, antitumor, and contraceptive agent makes it an interesting candidate to study every aspect of their structural and biological properties for prophylactic and therapeutic applications. In addition, easy cloning and recombinant expression of AMPs in heterologous plant host systems provided a pipeline for production of disease resistant transgenic plants. Besides these properties, AMPs were also used as drug delivery vectors to deliver cell impermeable drugs to cell interior. The present review focuses on the diversity and broad spectrum antimicrobial activity of AMPs along with its multidimensional properties that could be exploited for the application of these bioactive peptides as a potential and promising drug candidate in pharmaceutical industries. PMID:23935642

  2. Bioferroelectricity and optical properties of biological systems

    NASA Astrophysics Data System (ADS)

    Bystrov, Vladimir; Bystrova, Natalia

    2003-08-01

    A bioferroelectric approach to analysis of ferroelectric behavior of biological systems is presented. The optical properties of nerve fibers, biomembrane ion channels, and purple membrane films containing bacteriorhodopsin are analyzed. The features, influence of the proton subsystem and proton transfer on the hydrogen-bonded biomolecular structures are analyzed within the ferroelectric liquid-crystal model and possible biomedical applications discussed. The ferroelectric behavior of biological systems and the set of various bioferroelectric effects are considered within the limits of phenomenological theory of ferroelectrics. The nonlinear response to weak actions under conditions critical to human organism is one of specific features characterizing biological objects on molecular, cell and organism levels.

  3. Predicting Soil Biological and Physical Properties Using Hydrological Properties

    NASA Astrophysics Data System (ADS)

    Geiger, L.; Hofmockel, K.; Kaleita, A.; Hargreaves, S.

    2012-12-01

    Soil biological and chemical properties vary at different spatial scales, which make predicting processes associated with these properties difficult. However, soil biological and chemical properties are important to fertility and ecosystem functioning. In this study, we used a Self Organizing Map (SOM) to determine whether soil hydrological characteristics can be used to characterize the distribution of a suite of soil biological and chemical properties. From a row crop field in south-central Iowa, we generated 36 sampling locations via a SOM, which were grouped into three categories according to hydrological properties by the SOM. Soil samples were then analyzed for microbial biomass, carbon and nitrogen mineralization potential, and organic and inorganic pools of carbon and nitrogen. We found that sampling locations in category 1 (potholes and toe slopes) had greater microbial biomass, total carbon, total nitrogen, and extractable organic carbon than compared locations in the two well-drained categories. Nitrogen and carbon mineralization and inorganic nitrogen pools did not differ significantly among the categories. These results demonstrate that hydrological characteristics can be used to predict relatively stable biological and chemical soil properties. However, prediction of nitrogen and carbon fluxes remains a challenge.

  4. Physical and biological properties of Bazna waters

    PubMed Central

    TRÂMBIŢAŞ, DAN

    2013-01-01

    The healing properties of Bazna waters and their therapeutic indications have been well known since the 18th century. The objective of the present study was to characterize these waters from physical and biological points of view, and to further analyze the nitrogen compounds, especially NH4+. The following physical parameters of the water were analyzed: density (g/cm3), electric resistivity (Ω·m), electric conductivity (cm−1o−1), salinity, The pH analysis of the biological component was performed on samples from 4 basins. Nitrogen compounds were dosed in the form of ammonium ion (NH4+). The physical and chemical proprieties are similar across the basins. Flora and fauna biological components were identified. Ammonium ions were identified in large quantities, but this did not lead to hygienicaly unclean waters. PMID:26527972

  5. Biological Properties and Therapeutic Applications of Propolis.

    PubMed

    Sforcin, José M

    2016-06-01

    Propolis is a resinous material collected by bees from bud and exudates of the plants, mixed with bee enzymes, pollen and wax. In this review, the biological properties of propolis and some therapeutic applications are discussed. The same biological activities have been investigated until today, using samples from different geographic regions. Thus, the study of the biological properties of a given sample should always be associated with its chemical composition and botanical source, representing a particular sample of a given geographic area, exploring its biological potential and the role of its constituents. Efforts have been carried out to explain propolis' mechanisms of action in vivo and in vitro, but the majority of propolis' targets and actions are still unclear. The number of formulations containing propolis and patents have increased, although propolis extracts have been used deliberately with different recommendations, not always mentioning the chemical composition, vegetal source and the methods of extraction. Clinical studies will help to obtain criterious recommendations in view of the expected outcomes. Further investigation should explore the effects of common compounds found in the samples from all over the world in an attempt to standardize the research on propolis and to obtain new drugs. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26988443

  6. Phytochemistry and Biological Properties of Glabridin

    PubMed Central

    Simmler, Charlotte; Pauli, Guido F.; Chen, Shao-Nong

    2013-01-01

    Glabridin, a prenylated isoflavonoid of G. glabra L. roots (European licorice, Fabaceae), has been associated with a wide range of biological properties such as antioxidant, anti-inflammatory, anti-atherogenic, regulation of energy metabolism, estrogenic, neuroprotective, anti-osteoporotic, skin-whitening. While glabridin is one of the most studied licorice flavonoids, a comprehensive literature survey linked to its numerous bioactivities is unavailable. The present review provides a comprehensive description of glabridin as a key chemical and biological marker of G. glabra, by covering both its phytochemical characterization and reported biological activities. Both glabridin and standardized licorice extracts have significant impact on food, dietary supplements (DSs) and cosmetic markets, as evidenced by the amount of available patents and scientific articles since 1976, when glabridin was first described. Nevertheless, a thorough literature survey also reveals that information about the isolation and chemical characterization of this important marker is scattered and less detailed than expected. Accordingly, the first part of this review gathers all analytical and spectroscopic data required for the comprehensive phytochemical characterization of glabridin. The four most frequently described and most relevant bioactivities of glabridin are its anti-inflammatory, anti-atherogenic, estrogenic-like effects, and its capacity to regulate energy metabolism. While all bioactivities reported for glabridin belong to a wide array of targets, its principal biological properties are likely interconnected. To this end, the current state of the literature suggests that the biological activity of glabridin mainly results from its capacity to down-regulate intracellular reactive oxygen species, bind to antioxidant effectors, and act on estrogen receptors, potentially as a plant-based Selective Estrogen Receptor Modulator (phytoSERM). PMID:23850540

  7. Arbutus unedo L.: chemical and biological properties.

    PubMed

    Miguel, Maria G; Faleiro, Maria L; Guerreiro, Adriana C; Antunes, Maria D

    2014-01-01

    Arbutus unedo L. (strawberry tree) has a circum-Mediterranean distribution, being found in western, central and southern Europe, north-eastern Africa (excluding Egypt and Libya) and the Canary Islands and western Asia. Fruits of the strawberry tree are generally used for preparing alcoholic drinks (wines, liqueurs and brandies), jams, jellies and marmalades, and less frequently eaten as fresh fruit, despite their pleasing appearance. An overview of the chemical composition of different parts of the plant, strawberry tree honey and strawberry tree brandy will be presented. The biological properties of the different parts of A. unedo and strawberry tree honey will be also overviewed. PMID:25271425

  8. The Optical Properties of Biological Tissue.

    NASA Astrophysics Data System (ADS)

    Bews, Jeffrey Alan

    The ability of light to propagate through biological tissue has found much application in medicine (ie. Photodynamic therapy and Diaphanography). However, a poor understanding of this transport phenomenon has served to limit the effectiveness of those modalities employing it in their operation. This thesis is a study of light propagation through biological tissue, its goal being to improve on the lack of knowledge that presently exists. A spectrophotometer type instrument (DICOM-8) was developed to measure the diffuse spectra extinction of biological tissue. Results were obtained for both normal and diseased breast tissue. Extinction curves for the two tissues exhibited a similar shape (extinction monotonically decreasing with increasing wavelength) but differed in magnitude below 700 nm with carcinoma possessing a higher extinction than normal. Data obtained from these tissue measurements served as the basis for developing a homogeneous liquid (TEM) for simulating the optical properties of tissue over the range 550 to 900 nm. Bench-top Diaphanography studies carried out on a breast phantom constructed of TEM demonstrated the improved tumor visualization attainable with short wavelength light. TEM also functioned as a test medium in which light distributions resulting from highly controlled irradiation geometries (isotropic point and planar sources) were measured and compared with those predicted by Linear Transport (LT) theory. The mean free path (MFP) of TEM ranged from 0.206 mm at 550 nm to 0.495 mm at 900 nm and was found to be directly proportional to the square of the wavelength. The scatter/absorption coefficient (c) was 0.9986459 at 550 nm and 0.9997315 at 850 nm. Agreement between experimental and theoretical distributions was found to be extremely good. Theoretical distributions generated with LT theory revealed the fact that small changes in MFP will have little effect on light transport. Similar changes in c, meanwhile, will drastically alter the

  9. Goat herpesviruses: biological and physicochemical properties.

    PubMed

    Engels, M; Gelderblom, H; Darai, G; Ludwig, H

    1983-10-01

    Two herpesvirus isolates from goats are known which cause afflictions of the digestive tract in kids and, in some cases, abortion. An antigenic relationship of these goat herpesviruses with infectious bovine rhinotracheitis/infectious pustular vulvo-vaginitis virus (bovid herpesvirus 1, BHV-1) was reported and because of the species-specific pathogenicity, the goat isolates were named caprine herpesvirus 1. In this report the two isolates are further characterized and compared with BHV-1. Although the caprine herpesviruses share many biological and physicochemical properties with BHV-1, they can be differentiated from the bovine viruses with respect to growth cycle, one-way cross-neutralization and, most importantly, the restriction endonuclease fragments of their DNAs. The molecular weight of the caprine herpesvirus DNA, based on electron microscopic length measurement is 90 X 10(6), similar to that of BHV-1 (95 X 10(6]. On the basis of these genomic differences, we propose that DNA restriction endonuclease patterns of the caprine herpesviruses should be designated as prototypic of bovid herpesvirus 6 (BHV-6). PMID:6311953

  10. VISCOELASTIC PROPERTIES OF A BIOLOGICAL HYDROGEL PRODUCED FROM SOYBEAN OIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogels formed from biopolymers or natural sources have special advantages because of their biodegradable and biocompatible properties. The viscoelastic properties of a newly developed biological hydrogel made from modified vegetable oil, epoxidized soybean oil (ESO) were investigated. The mater...

  11. Mechanical and biological properties of keratose biomaterials.

    PubMed

    de Guzman, Roche C; Merrill, Michelle R; Richter, Jillian R; Hamzi, Rawad I; Greengauz-Roberts, Olga K; Van Dyke, Mark E

    2011-11-01

    The oxidized form of extractable human hair keratin proteins, commonly referred to as keratose, is gaining interest as a biomaterial for multiple tissue engineering studies including those directed toward peripheral nerve, spinal cord, skin, and bone regeneration. Unlike its disulfide cross-linked counterpart, kerateine, keratose does not possess a covalently cross-linked network structure and consequently displays substantially different characteristics. In order to understand its mode(s) of action and potential for clinical translatability, detailed characterization of the composition, physical properties, and biological responses of keratose biomaterials are needed. Keratose was obtained from end-cut human hair fibers by peracetic acid treatment, followed by base extraction, and subsequent dialysis. Analysis of lyophilized keratose powder determined that it contains 99% proteins by mass with amino acid content similar to human hair cortex. Metallic elements were also found in minute quantities. Protein oxidation led to disulfide bond cleavage and drastic reduction of free thiols due to conversion of sulfhydryl to sulfonic acid, chain fragmentation, and amino acid modifications. Mass spectrometry identified the major protein constituents as a heterogeneous mixture of 15 hair keratins (type I: K31-35 and K37-39, and type II: K81-86) with small amounts of epithelial keratins which exist in monomeric, dimeric, multimeric, and even degraded forms. Re-hydration with PBS enabled molecular assembly into an elastic solid-like hydrogel. Highly-porous scaffolds formed by lyophilization of the gel had the compression behavior of a cellular foam material and reverted back to gel upon wetting. Cytotoxicity assays showed that the EC50 for various cell lines were attained at 8-10 mg/mL keratose, indicating the non-toxic nature of the material. Implantation in mouse subcutaneous tissue pockets demonstrated that keratose resorption follows a rectangular hyperbolic regression

  12. Dynamic and rheological properties of soft biological cell suspensions

    PubMed Central

    Yazdani, Alireza; Li, Xuejin

    2016-01-01

    Quantifying dynamic and rheological properties of suspensions of soft biological particles such as vesicles, capsules, and red blood cells (RBCs) is fundamentally important in computational biology and biomedical engineering. In this review, recent studies on dynamic and rheological behavior of soft biological cell suspensions by computer simulations are presented, considering both unbounded and confined shear flow. Furthermore, the hemodynamic and hemorheological characteristics of RBCs in diseases such as malaria and sickle cell anemia are highlighted. PMID:27540271

  13. NANOSILVER MOVEMENT THROUGH BIOLOGICAL BARRIERS RELATES TO PHYSICOCHEMICAL PROPERTIES

    EPA Science Inventory

    Linking the physicochemical (PC) properties of engineered nanomaterials (NM) to their biological activity is critical for identifying their (toxic) mode of action, and developing appropriate and effective risk assessment guidelines. Particle surface charge (zeta potential), surfa...

  14. Insight into Biological Apatite: Physiochemical Properties and Preparation Approaches

    PubMed Central

    Liu, Quan; Matinlinna, Jukka Pekka; Chen, Zhuofan; Pan, Haobo

    2013-01-01

    Biological apatite is an inorganic calcium phosphate salt in apatite form and nano size with a biological derivation. It is also the main inorganic component of biological hard tissues such as bones and teeth of vertebrates. Consequently, biological apatite has a wide application in dentistry and orthopedics by using as dental fillers and bone substitutes for bone reconstruction and regeneration. Given this, it is of great significance to obtain a comprehensive understanding of its physiochemical and biological properties. However, upon the previous studies, inconsistent and inadequate data of such basic properties as the morphology, crystal size, chemical compositions, and solubility of biological apatite were reported. This may be ascribed to the differences in the source of raw materials that biological apatite are made from, as well as the effect of the preparation approaches. Hence, this paper is to provide some insights rather than a thorough review of the physiochemical properties as well as the advantages and drawbacks of various preparation methods of biological apatite. PMID:24078928

  15. SOME CHEMICAL PROPERTIES UNDERLYING ARSENIC'S BIOLOGICAL ACTIVITY

    EPA Science Inventory

    ABSTRACT

    In this paper some of the chemical properties of arsenicals (atomic
    and molecular orbitals, electronegativity, valence state, changes between
    valence state, nucleophilicity, the hard/soft acid/base principle) that may
    account for some of the b...

  16. Intellectual property conundrum for the biological sciences.

    PubMed

    Olds, James L

    2004-03-01

    Policy regarding academically generated biomedical intellectual property (IP) has been shaped by two important events: the Vannevar Bush report to then President Roosevelt in 1945 and the Bayh-Dole Act of 1980. This policy, which vests the intellectual property produced from federally funded biomedical research from the government to the academic institution, was designed to promote technology transfer and thus promote the health of the U.S. economy. However, the policy has led to significant challenges, particularly in implementation. Here it is argued that the difficulties are due to differences in the structure of motivations between biomedical scientists, institutional officials, and private sector entrepreneurs. Understanding these differences may lead to a review of policy with the goal of enhancing technology transfer for the future. PMID:15052648

  17. [Biological properties of immunochemically pure tetanus antitoxin].

    PubMed

    Kornilova, A V; Khavkin, Iu A; Batalova, T A; Aleksevich, Ia I; Baschenko, I A

    1983-02-01

    Immunochemically pure tetanus antitoxin obtained from enzyme-treated horse serum is less reactogenic and anaphylactogenic and possesses higher therapeutic properties than antitoxin purified by nonspecific physico-chemical methods and containing ballast antigens. Due to its increased persistence in the recipient's body, the immunochemically pure antitoxin induces passive immunity in considerably lower doses than the preparations purified by the method "Diaferm-3". PMID:6340393

  18. Biological Properties of Plant-Derived Alkylresorcinols: Mini-Review.

    PubMed

    Luís, Ângelo; Domingues, Fernanda; Duarte, Ana Paula

    2016-01-01

    Alkylresorcinols are compounds which belong to the family of phenolic lipids, and are usually found in numerous biological species. In the particular case of higher plants, alkylresorcinols have been found in various counterparts with chains of thirteen to twenty-seven carbon atoms containing several saturations. Due to the demonstrated antimicrobial properties of many naturally occurring members of the alkylresorcinols family, it is possible to conclude that these compounds act as defensive agents in plants. Previous studies led to the isolation and identification of 5-alkylresorcinols that cleave DNA. Additionally, in the literature, there are several other biological effects attributed to some resorcinol derivatives, namely, cytotoxic, anticarcinogenic, antiproliferative, antileishmanial and antioxidant properties. This mini-review intends to outline the biological activities of the most relevant alkylresorcinols isolated from plants and to propose future directions for subsequent studies regarding the effective biological effects of this class of compounds. PMID:26864549

  19. The diverse biological properties of the chemically inert noble gases.

    PubMed

    Winkler, David A; Thornton, Aaron; Farjot, Géraldine; Katz, Ira

    2016-04-01

    The noble gases represent an intriguing scientific paradox. They are extremely inert chemically but display a remarkable spectrum of clinically useful biological properties. Despite a relative paucity of knowledge of their mechanisms of action, some of the noble gases have been used successfully in the clinic. Studies with xenon have suggested that the noble gases as a class may exhibit valuable biological properties such as anaesthesia; amelioration of ischemic damage; tissue protection prior to transplantation; analgesic properties; and a potentially wide range of other clinically useful effects. Xenon has been shown to be safe in humans, and has useful pharmacokinetic properties such as rapid onset, fast wash out etc. The main limitations in wider use are that: many of the fundamental biochemical studies are still lacking; the lighter noble gases are likely to manifest their properties only under hyperbaric conditions, impractical in surgery; and administration of xenon using convectional gaseous anaesthesia equipment is inefficient, making its use very expensive. There is nonetheless a significant body of published literature on the biochemical, pharmacological, and clinical properties of noble gases but no comprehensive reviews exist that summarize their properties and the existing knowledge of their models of action at the molecular (atomic) level. This review provides such an up-to-date summary of the extensive, useful biological properties of noble gases as drugs and prospects for wider application of these atoms. PMID:26896563

  20. [Oregano: properties, composition and biological activity].

    PubMed

    Arcila-Lozano, Cynthia Cristina; Loarca-Piña, Guadalupe; Lecona-Uribe, Salvador; González de Mejía, Elvira

    2004-03-01

    The oregano spice includes various plant species. The most common are the genus Origanum, native of Europe, and the Lippia, native of Mexico. Among the species of Origanum. their most important components are the limonene, gamma-cariofilene, rho-cymenene, canfor, linalol, alpha-pinene, carvacrol and thymol. In the genus Lippia, the same compounds can be found. The oregano composition depends on the specie, climate, altitude, time of recollection and the stage of growth. Some of the properties of this plant's extracts are being currently studied due to the growing interest for substituting synthetic additives commonly found in foods. Oregano has a good antioxidant capacity and also presents antimicrobial activity against pathogenic microorganisms like Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, among others. These are all characteristics of interest for the food industry because they may enhance the safety and stability of foods. There are also some reports regarding the antimutagenic and anticarcinogenic effect of oregano; representing an alternative for the potential treatment and/or prevention of certain chronic ailments, like cancer. PMID:15332363

  1. Measuring Elastic Properties of Thin Biological Films Using Capillary Wrinkling

    NASA Astrophysics Data System (ADS)

    Iyer, N.; Cooper, K.; Yang, J.; Zenhausern, F.

    2008-08-01

    Imprinting of soft biological cells to create microenvironments for cell culture has gained significant importance in studying biological processes. Developments in soft lithography techniques have caused a decrease in the size of these imprinted biological cells. Where pattern sizes were in the range of 50 um, they are now being fabricated in the range of 1 um. However, there has been very little work done to characterize the elastic properties of these imprinted gels at this scale. In this work, we attempt to use an unique technique that uses the wrinkling that occurs when a floating thin film is subject to a normal loading force. A previous study has reported the use of this metrology method to measure elastic properties of floating thin polystyrene films by counting the number and length of wrinkles that are created when subjected to radial stresses from a droplet of water. In this case, we extend this theory to study wrinkle formation in floating polystyrene films coated with biological cells, and fibronectin. Also, we attempt to study capillary wrinkling in biological films such as agarose and Matrigel™. Wrinkles are induced in thin films of these materials by applying a droplet of fluid on the film surface. Using an appropriate scaling relationship, the elastic properties of these films may be obtained. The dependence of these elastic properties on gel aspect ratios, concentration, and, film floating media will be discussed.

  2. Dynamics of hydraulic properties due to biological clogging

    NASA Astrophysics Data System (ADS)

    Rosenzweig, R.; Shavit, U.; Furman, A.

    2012-04-01

    Classic treatment of soil-water flow is described by the unsaturated version of Darcy's law and Richards' equation, assuming time invariant hydraulic properties, e.g. the saturated hydraulic conductivity, Ks, and van Genuchten-Mualem's α and n. However, when bacteria is present the soil is quite far from being time invariant and biological activity constantly alters the pore-scale structure, leading to macro-scale alteration of the hydraulic properties. This may be of high relevance to processes such as subsurface bioremediation, soil aquifer treatment, wastewater irrigation, and more. In this work we explore the dynamic alteration of soil hydraulic properties by a combination of column experiments and pore-network modeling. We experimentally demonstrate how biological activity clogs an unsaturated soil column and reduces its hydraulic conductivity, while a similar column where biological activity is limited does not clog. Further, we demonstrate that the clogging is preferential to the nutrient input. Next, we develop a pore-network model that uses triangular shape channels. This allows a dual occupancy (water-air) of each channel and high connectivity. The model solves the flow of water, nutrient transport, and biological dynamics. It includes biofilm growth and decay, attachment and detachment, and nutrient exchange between the water and biofilm phases. We perform a sensitivity analysis of the model and qualitatively show through the loss of connectivity how the clogging that was observed in our experiment can be explained.

  3. Physicochemical Properties of Ion Pairs of Biological Macromolecules

    PubMed Central

    Iwahara, Junji; Esadze, Alexandre; Zandarashvili, Levani

    2015-01-01

    Ion pairs (also known as salt bridges) of electrostatically interacting cationic and anionic moieties are important for proteins and nucleic acids to perform their function. Although numerous three-dimensional structures show ion pairs at functionally important sites of biological macromolecules and their complexes, the physicochemical properties of the ion pairs are not well understood. Crystal structures typically show a single state for each ion pair. However, recent studies have revealed the dynamic nature of the ion pairs of the biological macromolecules. Biomolecular ion pairs undergo dynamic transitions between distinct states in which the charged moieties are either in direct contact or separated by water. This dynamic behavior is reasonable in light of the fundamental concepts that were established for small ions over the last century. In this review, we introduce the physicochemical concepts relevant to the ion pairs and provide an overview of the recent advancement in biophysical research on the ion pairs of biological macromolecules. PMID:26437440

  4. Group IV nanoparticles: synthesis, properties, and biological applications.

    PubMed

    Fan, Jiyang; Chu, Paul K

    2010-10-01

    In this review, the emerging roles of group IV nanoparticles including silicon, diamond, silicon carbide, and germanium are summarized and discussed from the perspective of biologists, engineers, and medical practitioners. The synthesis, properties, and biological applications of these new nanomaterials have attracted great interest in the past few years. They have gradually evolved into promising biomaterials due to their innate biocompatibility; toxic ions are not released when they are used in vitro or in vivo, and their wide fluorescence spectral regions span the near-infrared, visible, and near-ultraviolet ranges. Additionally, they generally have good resistance against photobleaching and have lifetimes on the order of nanoseconds to microseconds, which are suitable for bioimaging. Some of the materials possess unique mechanical, chemical, or physical properties, such as ultrachemical and thermal stability, high hardness, high photostability, and no blinking. Recent data have revealed the superiority of these nanoparticles in biological imaging and drug delivery. PMID:20730824

  5. Physical properties of biological entities: an introduction to the ontology of physics for biology.

    PubMed

    Cook, Daniel L; Bookstein, Fred L; Gennari, John H

    2011-01-01

    As biomedical investigators strive to integrate data and analyses across spatiotemporal scales and biomedical domains, they have recognized the benefits of formalizing languages and terminologies via computational ontologies. Although ontologies for biological entities-molecules, cells, organs-are well-established, there are no principled ontologies of physical properties-energies, volumes, flow rates-of those entities. In this paper, we introduce the Ontology of Physics for Biology (OPB), a reference ontology of classical physics designed for annotating biophysical content of growing repositories of biomedical datasets and analytical models. The OPB's semantic framework, traceable to James Clerk Maxwell, encompasses modern theories of system dynamics and thermodynamics, and is implemented as a computational ontology that references available upper ontologies. In this paper we focus on the OPB classes that are designed for annotating physical properties encoded in biomedical datasets and computational models, and we discuss how the OPB framework will facilitate biomedical knowledge integration. PMID:22216106

  6. Evaluation of biological cell properties using dynamic indentation measurement.

    PubMed

    Cao, Guoxin; Chandra, Namas

    2010-02-01

    Viscoelastic mechanical properties of biological cells are commonly measured using atomic force microscope (AFM) dynamic indentation with spherical tips. A semiempirical analysis based on numerical simulation is built to determine the cell mechanical properties. It is shown that the existing analysis cannot reflect the accurate values of cell elastic/dynamic modulus due to the effects of substrate, indenter tip size, and cell size. Among these factors, substrate not only increases the true contact radius but also interferes the indentation stress field, which can cause the overestimation of cell moduli. Typically, the substrate effect is much stronger than the other two influences in cell indentation; and, thus, the cell modulii are usually overestimated. It is estimated that the moduli can be overestimated by as high as over 200% using the existing analysis. In order to obtain the accurate properties of cells, correction factors that account for these effects are required in the existing analysis. PMID:20365612

  7. Light localization properties of biological cells via confocal imaging

    NASA Astrophysics Data System (ADS)

    Sahay, Peeyush; Ghimire, Hemendra M.; Almabadi, Huda; Pradhan, Prabhakar

    2015-03-01

    Detection and characterization of the spatial refractive index fluctuations of very weakly disordered optical dielectric media has ample applications in various fields ranging from soft condensed matter to biological research. We report a study of the submicron scale degree of the structural disorder of heterogeneous weakly disordered optical dielectric media, such as biological cells, by quantifying their submicron scale light-localization properties. Confocal microscopy is used to construct disordered optical lattices of these dielectric media. Light-localization properties are studied by the statistical analysis of the inverse participation ratio (IPR) of the localized eigenfunctions of these optical lattices at the submicron scales. The method is described and its importance is highlighted. As one of the applications, we demonstrate that using this method, different types of normal and cancerous cells can be distinguished by quantifying the structural disorder inside the cells via their confocal micrographs. Other potential applications of the technique to characterize weakly disordered media, as well as biological cells, in particular cancer detection, are also discussed. NIH and University of Memphis.

  8. EFFECTS OF A BIOLOGICAL AMENDMENT ON CHEMICAL AND BIOLOGICAL PROPERTIES AND MICROBIAL DIVERSITY IN SOILS RECEIVING DIFFERENT ORGANIC AMENDMENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological fertilizers consisting of suspensions of selected microorganisms are often used in conjunction with various organic materials for amending soils to improve soil quality and plant growth. The effects of a biological fertilizer on chemical and biological properties of soil were investigated...

  9. Chrysotile: its occurrence and properties as variables controlling biological effects.

    PubMed

    Langer, A M; Nolan, R P

    1994-08-01

    Chrysotile formation arises through serpentinization of ultramafics and silicified dolomitic limestones. Rock types tend to control the trace metal content and both the nature and amounts of admixed minerals in the ore, such as fibrous brucite (nemalite) and tremolite. Some associated minerals and trace metals are thought to play a role in biological potential. Tremolite, one of the important associated minerals, may occur with different morphological forms, called habits. These habits range from asbestiform (tremolite asbestos) to common blocky or non-fibrous form (tremolite cleavage fragments). The latter is most common in nature. Tremolite in chrysotile ore varies in habit and concentration, both factors determining the degree of risk following inhalation. Tremolite fibre is thought to be important in relation to the occurrence of mesothelioma. Chrysotile fibrils may vary in diameter. Dust clouds generated following manipulation vary in fibre number and surface area. Chrysotile fibres exhibit a range of physical characteristics. The fibre may be non-flexible ('stiff') and low in tensile strength ('brittle'), and may lack an ability to curl. This fibre, referred to as 'harsh', sheds water more quickly than its curly, flexible 'soft' variety. The behaviour of the harsh fibres is more amphibole-like and their splintery nature suggests an enhanced inhalation potential. Slip fibre ore from Canada tends to contain more fibrous brucite (nemalite) than cross-fibre ore in the same mine. Industrial manipulation, which includes chemical treatment, heating and milling, may impart new surface properties to chrysotile dusts. Biological potential may be enhanced (opening of fibre bundles) or reduced (disruption of surface bonds and lessened ability to interact with organic moieties). Leaching of magnesium from chrysotile occurs at a pH less than about 10. Chrysotile has been demonstrated to lose magnesium in vivo and undergo clearance from the lung. The biological potential of

  10. Biological activities and medicinal properties of Gokhru (Pedalium murex L.)

    PubMed Central

    Rajashekar, V; Rao, E Upender; P, Srinivas

    2012-01-01

    Bada Gokhru (Pedalium murex L.) is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has some medicinal property and is thus commercially exploitable. During the last five decades, apart from the chemistry of the Pedalium murex compounds, considerable progress has been achieved regarding the biological activity and medicinal applications of this plant. It is now considered as a valuable source of unique natural products for development of medicines against various diseases and also for the development of industrial products. This review gives a bird's eye view mainly on the biological activities of some of this compounds isolated, pharmacological actions of the extracts, clinical studies and plausible medicinal applications of gokharu along with their safety evaluation. PMID:23569975

  11. Biological properties of mesenchymal Stem Cells from different sources

    PubMed Central

    Giai Via, Alessio; Frizziero, Antonio; Oliva, Francesco

    2012-01-01

    Summary Mesenchymal stem cells (MSCs) are adult, nonhematopoietic, stem cells that were initially isolated from bone marrow. Now they can be isolated from almost every tissue of the body. They have the ability to self-renew and differentiate into multiple cell lineage, including bone, chondrocytes, adipocytes, tenocytes and cardiomyocytes, and it makes them an attractive cell source for a new generation of cell-based regenerative therapies. In this review we try to summarize data on sources and the biological properties of MSCs. PMID:23738292

  12. Physical Properties of Biological Entities: An Introduction to the Ontology of Physics for Biology

    PubMed Central

    Cook, Daniel L.; Bookstein, Fred L.; Gennari, John H.

    2011-01-01

    As biomedical investigators strive to integrate data and analyses across spatiotemporal scales and biomedical domains, they have recognized the benefits of formalizing languages and terminologies via computational ontologies. Although ontologies for biological entities—molecules, cells, organs—are well-established, there are no principled ontologies of physical properties—energies, volumes, flow rates—of those entities. In this paper, we introduce the Ontology of Physics for Biology (OPB), a reference ontology of classical physics designed for annotating biophysical content of growing repositories of biomedical datasets and analytical models. The OPB's semantic framework, traceable to James Clerk Maxwell, encompasses modern theories of system dynamics and thermodynamics, and is implemented as a computational ontology that references available upper ontologies. In this paper we focus on the OPB classes that are designed for annotating physical properties encoded in biomedical datasets and computational models, and we discuss how the OPB framework will facilitate biomedical knowledge integration. PMID:22216106

  13. Biochemical Properties and Biological Functions of FET Proteins.

    PubMed

    Schwartz, Jacob C; Cech, Thomas R; Parker, Roy R

    2015-01-01

    Members of the FET protein family, consisting of FUS, EWSR1, and TAF15, bind to RNA and contribute to the control of transcription, RNA processing, and the cytoplasmic fates of messenger RNAs in metazoa. FET proteins can also bind DNA, which may be important in transcription and DNA damage responses. FET proteins are of medical interest because chromosomal rearrangements of their genes promote various sarcomas and because point mutations in FUS or TAF15 can cause neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal lobar dementia. Recent results suggest that both the normal and pathological effects of FET proteins are modulated by low-complexity or prion-like domains, which can form higher-order assemblies with novel interaction properties. Herein, we review FET proteins with an emphasis on how the biochemical properties of FET proteins may relate to their biological functions and to pathogenesis. PMID:25494299

  14. Mechanical and biological properties of oxidized horn keratin.

    PubMed

    Zhang, Quanbin; Shan, Guanghua; Cao, Ping; He, Jia; Lin, Zhongshi; Huang, Yaoxiong; Ao, Ningjian

    2015-02-01

    The goal of this study was to investigate the mechanical and biological properties of oxidized keratin materials, which were obtained by using buffalo horns to oxidize. It could provide a way to evaluate their potential for clinical translatability. The characterization on their composition, mechanical properties, and biological responses was performed. It is found that the oxidation process could lead the disulfide bond to break down and then to form sulfonic acid, or even make partial peptide chain to be fragment for the new modification of amino acid. Hence the oxidized horn keratins have lower thermal stability and hydrolytic stability in comparison with horn keratin, but the degradation products of oxidized horn keratins have no significant difference. In addition, the mechanical properties of oxidized horn keratins are poorer than that of horn keratin, but the oxidized horn keratins still have disulfide bonds to form a three-dimensional structure, which benefits for their mechanical properties. The fracture toughness of oxidized horn keratins increases with the increase in the degree of oxidation. After oxidation, the oxidized horn keratins have lower cytotoxicity and lower hemolysis ratio. Moreover, when the oxidized horn keratins, as well as different concentration of degradation products of oxidized horn keratins, are directly in contact with platelet-rich plasma, platelets are not activated. It suggests that the oxidized horn keratins have good hemocompatibility, without triggering blood thrombosis. The implantation experiment in vivo also demonstrates that the oxidized horn keratins are compatible with the tissue, because there are minimal fibrous capsule and less of infiltration of host cells, without causing serious inflammation. In summary, the oxidized horn keratins can act as implanted biomaterial devices that are directly in contact with blood and tissue. PMID:25492180

  15. Biological glass fibers: Correlation between optical and structural properties

    PubMed Central

    Aizenberg, Joanna; Sundar, Vikram C.; Yablon, Andrew D.; Weaver, James C.; Chen, Gang

    2004-01-01

    Biological systems have, through the course of time, evolved unique solutions for complex optical problems. These solutions are often achieved through a sophisticated control of fine structural features. Here we present a detailed study of the optical properties of basalia spicules from the glass sponge Euplectella aspergillum and reconcile them with structural characteristics. We show these biosilica fibers to have a distinctive layered design with specific compositional variations in the glass/organic composite and a corresponding nonuniform refractive index profile with a high-index core and a low-index cladding. The spicules can function as single-mode, few-mode, or multimode fibers, with spines serving as illumination points along the spicule shaft. The presence of a lens-like structure at the end of the fiber increases its light-collecting efficiency. Although free-space coupling experiments emphasize the similarity of these spicules to commercial optical fibers, the absence of any birefringence, the presence of technologically inaccessible dopants in the fibers, and their improved mechanical properties highlight the advantages of the low-temperature synthesis used by biology to construct these remarkable structures. PMID:14993612

  16. Biological Properties of Acidic Cosmetic Water from Seawater

    PubMed Central

    Liao, Wei-Ting; Huang, Tsi-Shu; Chiu, Chien-Chih; Pan, Jian-Liang; Liang, Shih-Shin; Chen, Bing-Hung; Chen, Shi-Hui; Liu, Po-Len; Wang, Hui-Chun; Wen, Zhi-Hong; Wang, Hui-Min; Hsiao, Shu-Wen

    2012-01-01

    This current work was to investigate the biological effects of acidic cosmetic water (ACW) on various biological assays. ACW was isolated from seawater and demonstrated several bio-functions at various concentration ranges. ACW showed a satisfactory effect against Staphylococcus aureus, which reduced 90% of bacterial growth after a 5-second exposure. We used cultured human peripheral blood mononuclear cells (PBMCs) to test the properties of ACW in inflammatory cytokine release, and it did not induce inflammatory cytokine release from un-stimulated, normal PBMCs. However, ACW was able to inhibit bacterial lipopolysaccharide (LPS)-induced inflammatory cytokine TNF-α released from PBMCs, showing an anti-inflammation potential. Furthermore, ACW did not stimulate the rat basophilic leukemia cell (RBL-2H3) related allergy response on de-granulation. Our data presented ACW with a strong anti-oxidative ability in a superoxide anion radical scavenging assay. In mass spectrometry information, magnesium and zinc ions demonstrated bio-functional detections for anti-inflammation as well as other metal ions such as potassium and calcium were observed. ACW also had minor tyrosinase and melanin decreasing activities in human epidermal melanocytes (HEMn-MP) without apparent cytotoxicity. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects of ACW on human skin melanoma cells (A375.S2) indicating that it exerted the anti-cancer potential against skin cancer. The results obtained from biological assays showed that ACW possessed multiple bioactivities, including anti-microorganism, anti-inflammation, allergy-free, antioxidant, anti-melanin and anticancer properties. To our knowledge, this was the first report presenting these bioactivities on ACW. PMID:22754342

  17. Probing mechanical properties of fully hydrated gels and biological tissues.

    PubMed

    Constantinides, Georgios; Kalcioglu, Z Ilke; McFarland, Meredith; Smith, James F; Van Vliet, Krystyn J

    2008-11-14

    A longstanding challenge in accurate mechanical characterization of engineered and biological tissues is maintenance of both stable sample hydration and high instrument signal resolution. Here, we describe the modification of an instrumented indenter to accommodate nanomechanical characterization of biological and synthetic tissues in liquid media, and demonstrate accurate acquisition of force-displacement data that can be used to extract viscoelastoplastic properties of hydrated gels and tissues. We demonstrate the validity of this approach via elastoplastic analysis of relatively stiff, water-insensitive materials of elastic moduli E>1000 kPa (borosilicate glass and polypropylene), and then consider the viscoelastic response and representative mechanical properties of compliant, synthetic polymer hydrogels (polyacrylamide-based hydrogels of varying mol%-bis crosslinker) and biological tissues (porcine skin and liver) of E<500 kPa. Indentation responses obtained via loading/unloading hystereses and contact creep loading were highly repeatable, and the inferred E were in good agreement with available macroscopic data for all samples. As expected, increased chemical crosslinking of polyacrylamide increased stiffness (E40 kPa) and decreased creep compliance. E of porcine liver (760 kPa) and skin (222 kPa) were also within the range of macroscopic measurements reported for a limited subset of species and disease states. These data show that instrumented indentation of fully immersed samples can be reliably applied for materials spanning several orders of magnitude in stiffness (E=kPa-GPa). These capabilities are particularly important to materials design and characterization of macromolecules, cells, explanted tissues, and synthetic extracellular matrices as a function of spatial position, degree of hydration, or hydrolytic/enzymatic/corrosion reaction times. PMID:18922534

  18. Millimeter wave and terahertz dielectric properties of biological materials

    NASA Astrophysics Data System (ADS)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  19. Correlating the morphological and light scattering properties of biological cells

    NASA Astrophysics Data System (ADS)

    Moran, Marina

    The scattered light pattern from a biological cell is greatly influenced by the internal structure and optical properties of the cell. This research project examines the relationships between the morphological and scattering properties of biological cells through numerical simulations. The mains goals are: (1) to develop a procedure to analytically model biological cells, (2) to quantitatively study the effects of a range of cell characteristics on the features of the light scattering patterns, and (3) to classify cells based on the features of their light scattering patterns. A procedure to create an analytical cell model was developed which extracted structural information from the confocal microscopic images of cells and allowed for the alteration of the cell structure in a controlled and systematic way. The influence of cell surface roughness, nuclear size, and mitochondrial volume density, spatial distribution, size and shape on the light scattering patterns was studied through numerical simulations of light scattering using the Discrete Dipole Approximation. It was found that the light scattering intensity in the scattering angle range of 25° to 45° responded to changes in the surface fluctuation of the cell and the range of 90° to 110° was well suited for characterization of mitochondrial density and nuclear size. A comparison of light scattering pattern analysis methods revealed that the angular distribution of the scattered light and Gabor filters were most helpful in differentiating between the cell characteristics. In addition, a measured increase in the Gabor energy of the light scattering patterns in response to an increase in the complexity of the cell models suggested that a complex nuclear structure and mitochondria should be included when modeling biological cells for light scattering simulations. Analysis of the scattering pattern features with Gabor filters resulted in discrimination of the cell models according to cell surface roughness

  20. Structural, biological and biophysical properties of glycated and glycoxidized phosphatidylethanolamines.

    PubMed

    Annibal, Andrea; Riemer, Thomas; Jovanovic, Olga; Westphal, Dennis; Griesser, Eva; Pohl, Elena E; Schiller, Jürgen; Hoffmann, Ralf; Fedorova, Maria

    2016-06-01

    Glycation and glycoxidation of proteins and peptides have been intensively studied and are considered as reliable diagnostic biomarkers of hyperglycemia and early stages of type II diabetes. However, glucose can also react with primary amino groups present in other cellular components, such as aminophospholipids (aminoPLs). Although it is proposed that glycated aminoPLs can induce many cellular responses and contribute to the development and progression of diabetes, the routes of their formation and their biological roles are only partially revealed. The same is true for the influence of glucose-derived modifications on the biophysical properties of PLs. Here we studied structural, signaling, and biophysical properties of glycated and glycoxidized phosphatidylethanolamines (PEs). By combining high resolution mass spectrometry and nuclear magnetic resonance spectroscopy it was possible to deduce the structures of several intermediates indicating an oxidative cleavage of the Amadori product yielding glycoxidized PEs including advanced glycation end products, such as carboxyethyl- and carboxymethyl-ethanolamines. The pro-oxidative role of glycated PEs was demonstrated and further associated with several cellular responses including activation of NFκB signaling pathways. Label free proteomics indicated significant alterations in proteins regulating cellular metabolisms. Finally, the biophysical properties of PL membranes changed significantly upon PE glycation, such as melting temperature (Tm), membrane surface charge, and ion transport across the phospholipid bilayer. PMID:27012418

  1. Physiochemical and biological properties of phosphorylated polysaccharides from Dictyophora indusiata.

    PubMed

    Deng, Chao; Fu, Haitian; Xu, Jingjing; Shang, Jingying; Cheng, Yongmei

    2015-01-01

    In this study, we aim to investigate the physiochemical and biological properties of water-soluble phosphorylated polysaccharides (P-DIP) obtained from a water-insoluble polysaccharide (DIP) extracted from Dictyophora indusiata. A series of physiochemical properties were determined, including morphology, water-solubility, molecular weight, and degree of substitution (DS). To investigate the antioxidant activity of P-DIP, we determined the scavenging activity of hydroxyl radicals and DPPH, as well as the reducing power. MTT assay was performed to determine the cytotoxic effects of DIP and P-DIP on the cellular proliferation of MCF-7 and B16 cells. Compared with DIP, P-DIP showed a satisfactory water-solubility and significant increase in the antioxidant properties. Moreover, P-DIP also showed more significant inhibitory effects on the growth of MCF-7 and B16 tumor cells than the water-insoluble DIP. These results indicated that phosphorylation might contribute to the improvement of water solubility, as well as antioxidant and anti-tumor activities of natural DIP. PMID:25316421

  2. Menthol: a simple monoterpene with remarkable biological properties.

    PubMed

    Kamatou, Guy P P; Vermaak, Ilze; Viljoen, Alvaro M; Lawrence, Brian M

    2013-12-01

    Menthol is a cyclic monoterpene alcohol which possesses well-known cooling characteristics and a residual minty smell of the oil remnants from which it was obtained. Because of these attributes it is one of the most important flavouring additives besides vanilla and citrus. Due to this reason it is used in a variety of consumer products ranging from confections such as chocolate and chewing gum to oral-care products such as toothpaste as well as in over-the-counter medicinal products for its cooling and biological effects. Its cooling effects are not exclusive to medicinal use. Approximately one quarter of the cigarettes on the market contain menthol and small amounts of menthol are even included in non-mentholated cigarettes. Natural menthol is isolated exclusively from Mentha canadensis, but can also be synthesised on industrial scale through various processes. Although menthol exists in eight stereoisomeric forms, (-)-menthol from the natural source and synthesised menthol with the same structure is the most preferred isomer. The demand for menthol is high and it was previously estimated that the worldwide use of menthol was 30-32,000 metric tonnes per annum. Menthol is not a predominant compound of the essential oils as it can only be found as a constituent of a limited number of aromatic plants. These plants are known to exhibit biological activity in vitro and in vivo such as antibacterial, antifungal, antipruritic, anticancer and analgesic effects, and are also an effective fumigant. In addition, menthol is one of the most effective terpenes used to enhance the dermal penetration of pharmaceuticals. This review summarises the chemical and biological properties of menthol and highlights its cooling effects and toxicity. PMID:24054028

  3. Acinetobacter lipases: molecular biology, biochemical properties and biotechnological potential.

    PubMed

    Snellman, Erick A; Colwell, Rita R

    2004-10-01

    Lipases (EC 3.1.1.3) have received increased attention recently, evidenced by the increasing amount of information about lipases in the current literature. The renewed interest in this enzyme class is due primarily to investigations of their role in pathogenesis and their increasing use in biotechnological applications. Also, many microbial lipases are available as commercial products, the majority of which are used in detergents, cosmetic production, food flavoring, and organic synthesis. Lipases are valued biocatalysts because they act under mild conditions, are highly stable in organic solvents, show broad substrate specificity, and usually show high regio- and/or stereo-selectivity in catalysis. A number of lipolytic strains of Acinetobacter have been isolated from a variety of sources and their lipases possess many biochemical properties similar to those that have been developed for biotechnological applications. This review discusses the biology of lipase expression in Acinetobacter, with emphasis on those aspects relevant to potential biotechnology applications. PMID:15378387

  4. Biological and therapeutic activities, and anticancer properties of curcumin

    PubMed Central

    PERRONE, DONATELLA; ARDITO, FATIMA; GIANNATEMPO, GIOVANNI; DIOGUARDI, MARIO; TROIANO, GIUSEPPE; LO RUSSO, LUCIO; DE LILLO, ALFREDO; LAINO, LUIGI; LO MUZIO, LORENZO

    2015-01-01

    Curcumin (diferuloylmethane) is a polyphenol derived from the Curcuma longa plant. Curcumin has been used extensively in Ayurvedic medicine, as it is nontoxic and exhibits a variety of therapeutic properties, including antioxidant, analgesic, anti-inflammatory and antiseptic activities. Recently, certain studies have indicated that curcumin may exert anticancer effects in a variety of biological pathways involved in mutagenesis, apoptosis, tumorigenesis, cell cycle regulation and metastasis. The present study reviewed previous studies in the literature, which support the therapeutic activity of curcumin in cancer. In addition, the present study elucidated a number of the challenges concerning the use of curcumin as an adjuvant chemotherapeutic agent. All the studies reviewed herein suggest that curcumin is able to exert anti-inflammatory, antiplatelet, antioxidative, hepatoprotective and antitumor activities, particularly against cancers of the liver, skin, pancreas, prostate, ovary, lung and head neck, as well as having a positive effect in the treatment of arthritis. PMID:26640527

  5. Ethical and intellectual property in the biological sciences.

    PubMed

    Maher, E A

    1997-05-01

    Ethical concerns on patents in the biological sciences are increased by the prospect of patents for higher life forms. A Canadian patent grants the owner the right to exclude others in Canada from making, using, or selling or offering for sale his or her invention for the term of the patent; however, it does not give the patent owner any positive rights to do likewise. As with other forms of property, the right to make, use, or sell a patented invention may be regulated by other laws or guidelines. In Canada, higher life forms, medical and surgical methods are not patentable subject matter. Unicellular life forms and subcellular material are considered patentable. Decisions on ethical issues are not considered by patent officers. The Patent Office is guided only by legislation. Other regulations by the legislatures can direct public policy and minimize risks. PMID:9193780

  6. Biological and therapeutic properties of bee pollen: a review.

    PubMed

    Denisow, Bożena; Denisow-Pietrzyk, Marta

    2016-10-01

    Natural products, including bee products, are particularly appreciated by consumers and are used for therapeutic purposes as alternative drugs. However, it is not known whether treatments with bee products are safe and how to minimise the health risks of such products. Among others, bee pollen is a natural honeybee product promoted as a valuable source of nourishing substances and energy. The health-enhancing value of bee pollen is expected due to the wide range of secondary plant metabolites (tocopherol, niacin, thiamine, biotin and folic acid, polyphenols, carotenoid pigments, phytosterols), besides enzymes and co-enzymes, contained in bee pollen. The promising reports on the antioxidant, anti-inflammatory, anticariogenic antibacterial, antifungicidal, hepatoprotective, anti-atherosclerotic, immune enhancing potential require long-term and large cohort clinical studies. The main difficulty in the application of bee pollen in modern phytomedicine is related to the wide species-specific variation in its composition. Therefore, the variations may differently contribute to bee-pollen properties and biological activity and thus in therapeutic effects. In principle, we can unequivocally recommend bee pollen as a valuable dietary supplement. Although the bee-pollen components have potential bioactive and therapeutic properties, extensive research is required before bee pollen can be used in therapy. © 2016 Society of Chemical Industry. PMID:27013064

  7. Comparison of biological chromophores: photophysical properties of cyanophenylalanine derivatives.

    PubMed

    Martin, Joshua P; Fetto, Natalie R; Tucker, Matthew J

    2016-07-27

    Within this work, the family of cyanophenylalanine spectroscopic reporters is extended by showing the ortho and meta derivatives have intrinsic photophysical properties that are useful for studies of protein structure and dynamics. The molar absorptivities of 2-cyanophenylalanine and 3-cyanophenylalanine are shown to be comparable to that of 4-cyanophenylalanine with similar spectral features in their absorbance and emission profiles, demonstrating that these probes can be utilized interchangeably. The fluorescence quantum yields are also on the same scale as commonly used fluorophores in peptides and proteins, tyrosine and tryptophan. These new cyano-fluorophores can be paired with either 4-cyanophenylalanine or tryptophan to capture distances in peptide structure through Förster resonance energy transfer. Additionally, the spectroscopic properties of these chromophores can report the local solvent environment via changes in fluorescence emission intensity as a result of hydrogen bonding and/or hydration. A decrease in the quantum yield is also observed in basic environments due to photoinduced electron transfer from a deprotonated amine in the free PheCN species and at the N-terminus of a short peptide, providing an avenue to detect pH in biological systems. Our results show the potential of these probes, 2-cyanophenylalanine and 3-cyanophenylalanine, to be incorporated into a single peptide chain, either individually or in tandem with 4-cyanophenylalanine, tryptophan, or tyrosine, in order to obtain information about peptide structure and dynamics. PMID:27412819

  8. Mathematically modeling the biological properties of gliomas: A review.

    PubMed

    Martirosyan, Nikolay L; Rutter, Erica M; Ramey, Wyatt L; Kostelich, Eric J; Kuang, Yang; Preul, Mark C

    2015-08-01

    Although mathematical modeling is a mainstay for industrial and many scientific studies, such approaches have found little application in neurosurgery. However, the fusion of biological studies and applied mathematics is rapidly changing this environment, especially for cancer research. This review focuses on the exciting potential for mathematical models to provide new avenues for studying the growth of gliomas to practical use. In vitro studies are often used to simulate the effects of specific model parameters that would be difficult in a larger-scale model. With regard to glioma invasive properties, metabolic and vascular attributes can be modeled to gain insight into the infiltrative mechanisms that are attributable to the tumor's aggressive behavior. Morphologically, gliomas show different characteristics that may allow their growth stage and invasive properties to be predicted, and models continue to offer insight about how these attributes are manifested visually. Recent studies have attempted to predict the efficacy of certain treatment modalities and exactly how they should be administered relative to each other. Imaging is also a crucial component in simulating clinically relevant tumors and their influence on the surrounding anatomical structures in the brain. PMID:25974347

  9. Optical characterization of thermal properties of biological tissue

    NASA Astrophysics Data System (ADS)

    Gutierrez-Arroyo, A.; Sánchez Pérez, C.; Alemán-García, N.; Piña-Barba, C.

    2013-11-01

    In this work we utilize heat conduction measurements trough the photothermal beam deflection technique to characterize thermal properties of biological tissue. We design a heat flux sensor based on the phenomenon of photothermal laser beam deflection within a thermo-optic slab (acrylic), where the deflection is quantified by an optical fiber angle sensor. We analytically model the heat flux sensor response based on heat wave propagation theory that well agree with experimental data. We present heat conduction measurements on different tissues applying a heat pulse. Hence we obtain the thermal effusivity coefficient of bovine tendon and chicken liver and heart. It has been shown that thermal conduction depends on the tissués chemical composition as well on their structural arrangements, so any modification in tissue will affect on heat conduction rendering this method potentially useful as an auxiliary in biomedical studies. Nowadays there are several thermal effusivity and diffusivity measurement techniques with classic calorimetry (using thermistors) for research and industrial applications. However there are only few integrated optical devices already proposed, turning this optical technique in an innovative and alternative sensing system for thermal properties characterization.

  10. Inverse Algorithm Optimization for Determining Optical Properties of Biological Materials from Spatially-Resolved Diffuse Reflectance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optical characterization of biological materials is useful in many scientific and industrial applications like biomedical diagnosis and nondestructive quality evaluation of food and agricultural products. However, accurate determination of the optical properties from intact biological materials base...

  11. [Biological properties and therapeutic use of interleukin 2 (IL-2)].

    PubMed

    Robak, T

    1995-01-01

    A cytokine produced by the subpopulation of activated helper lymphocytes T has been called interleukin-2 (IL-2). The obtaining of recombinant cytokine has facilitated the study of its biological properties and its application in the treatment of certain neoplastic and infectious diseases. IL-2 affects the target cells by means of a receptor of great affinity consisting of three independent chains: alpha, beta, gamma. The cytokine is the most important growth factor of lymphocytes T, conditioning their clonal expansion. Antigen stimulation is the condition for the expression of IL-2 does not, however, affect resting lymphocytes T. The expression of the receptor for this cytokine on NK cells is, however, continuous in character but only a very small percentage of these cells has receptors of great affinity. IL-2 plays a great role in adoptive immunotherapy consisting in intravenous administration of cells with cytotoxic properties. Cells obtained from peripheral blood and grown in vitro are called LAK cells (lymphocyte activated killer cells), while cells obtained from neoplasms and grown in similar conditions are named TIL cells (tumor infiltrated lymphocytes). LAK and TIL cells reveal a similar antineoplastic activity in vivo. At present, however, recombinant IL-2 alone is used more often, either intravenously or subcutaneously. The cytokine is effective in the treatment of patients with disseminate cancer of the kidney and melanoma, and in adjuvant therapy of acute myeloid leukemia. Attempts have been made to apply it in the treatment of AIDS and leprosy. The toxic effect of IL-2 depends on the dose and the mode of administration. In the majority of patients parainfluenza symptoms appear. Most undesirable effects are connected with multisystemic syndrome of capillary vessels hyperpermeability leading to the increased fluid retention into extravascular spaces, oedema, hypotonia and oliguria. PMID:8657637

  12. Impact of temperature on the biological properties of soil

    NASA Astrophysics Data System (ADS)

    Borowik, Agata; Wyszkowska, Jadwiga

    2016-01-01

    The aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase - at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

  13. Chenopodium album Linn: review of nutritive value and biological properties.

    PubMed

    Poonia, Amrita; Upadhayay, Ashutosh

    2015-07-01

    Green leafy vegetables have generated interest worldwide as they exhibit multiple benefits for health of human beings. Vegetables can form the cheapest and most readily available sources of important vitamins, minerals, fibres and essential amino acids particularly. In most of the developing countries where the daily diet is dominated by starchy staple foods, vegetables can form the cheapest and most readily available sources of important vitamins, minerals, fibres and essential amino acids. Across the globe there are several local and wild vegetables which are under-exploited because of inadequate scientific information on knowledge of their nutritional potentials. A resurgence of interest has developed in wild vegetables for their possible medicinal values in diets. C. album is under exploited vegetable which has high functional potential apart from basic nutritional benefits. The plant is used in diet not only to provide minerals, fibre, vitamins and essential fatty acids but also enhance sensory and functional value of the food. The plant has been traditionally used as a bloodpurifier, diuretic, sedative, hepatoprotective, antiscorbutic laxative and as an anthelmentic against round and hookworms. Pharmacological studies have revealed that the plant possesses anthelmentic, sperm immobilizing and contraceptive properties. It is also claimed to be antipruritic and antinociceptive in action. Therefore C. album holds a great potential for in depth biological evaluation. No significant work has ever been carried out for processing parameters for this potentially useful plant. Significance and future scope of C. album for public and dietary awareness of its nutritional status has been discussed in this review. PMID:26139865

  14. Essential oils from neotropical Myrtaceae: chemical diversity and biological properties.

    PubMed

    Stefanello, Maria Élida Alves; Pascoal, Aislan C R F; Salvador, Marcos J

    2011-01-01

    Myrtaceae family (121 genera, 3800-5800 spp.) is one of the most important families in tropical forests. They are aromatic trees or shrubs, which frequently produce edible fruits. In the neotropics, ca. 1000 species were found. Several members of this family are used in folk medicine, mainly as an antidiarrheal, antimicrobial, antioxidant, cleanser, antirheumatic, and anti-inflammatory agent and to decrease the blood cholesterol. In addition, some fruits are eaten fresh or used to make juices, liqueurs, and sweets very much appreciated by people. The flavor composition of some fruits belonging to the Myrtaceae family has been extensively studied due to their pleasant and intense aromas. Most of the essential oils of neotropical Myrtaceae analyzed so far are characterized by predominance of sesquiterpenes, some with important biological properties. In the present work, chemical and pharmacological studies carried out on neotropical Myrtaceae species are reviewed, based on original articles published since 1980. The uses in folk medicine and chemotaxonomic importance of secondary metabolites are also briefly discussed. PMID:21259421

  15. Dynamic properties of biologically active synthetic heparin-like hexasaccharides.

    PubMed

    Angulo, Jesús; Hricovíni, Milos; Gairi, Margarida; Guerrini, Marco; de Paz, José Luis; Ojeda, Rafael; Martín-Lomas, Manuel; Nieto, Pedro M

    2005-10-01

    A complete study of the dynamics of two synthetic heparin-like hexasaccharides, D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (1) and -->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHAc-6-SO4-alpha-(1-->4)-L-IdoA-alpha-(1-->4)-D-GlcNHSO3-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (2), has been performed using 13C-nuclear magnetic resonance (NMR) relaxation parameters, T1, T2, and heteronuclear nuclear Overhauser effect (NOEs). Compound 1 is constituted from sequences corresponding to the major polysaccharide heparin region, while compound 2 contains a sequence never found in natural heparin. They differ from each other only in sulphation patterns, and are capable of stimulating fibroblast growth factors (FGFs)-1 induced mitogenesis. Both oligosaccharides exhibit a remarkable anisotropic overall motion in solution as revealed by their anisotropic ratios (tau /tau||), 4.0 and 3.0 respectively. This is a characteristic behaviour of natural glycosaminoglycans (GAG) which has also been observed for the antithrombin (AT) binding pentasaccharide D-GlcNHSO3-6-SO4-alpha-(1-->4)-D-GlcA-beta-(1-->4)-D-GlcNHSO3-(3,6-SO4)-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-1-->Me (3) (Hricovíni, M., Guerrini, M., Torri, G., Piani, S., and Ungarelli, F. (1995) Conformational analysis of heparin epoxide in aqueous solution. An NMR relaxation study. Carbohydr. Res., 277, 11-23). The motional properties observed for 1 and 2 provide additional support to the suitability of these compounds as heparin models in agreement with previous structural (de Paz, J.L., Angulo, J., Lassaletta, J.M., Nieto, P.M., Redondo-Horcajo, M., Lozano, R.M., Jiménez-Gallego, G., and Martín-Lomas, M. (2001) The activation of fibroblast growth factors by heparin: synthesis, structure and biological activity of heparin-like oligosaccharides. Chembiochem, 2, 673-685; Ojeda, R

  16. Biological residues define the ice nucleation properties of soil dust

    NASA Astrophysics Data System (ADS)

    Conen, F.; Morris, C. E.; Leifeld, J.; Yakutin, M. V.; Alewell, C.

    2011-09-01

    Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nucleation sites per unit mass active in the immersion freezing mode at -12 °C than montmorillonite, the nucleation properties of which are often used to represent those of mineral dusts in modelling studies. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

  17. Optical Properties and Biological Applications of Electromagnetically Coupled Metal Nanoparticles

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Sassan Nathan

    The optical properties of metallic particles change dramatically as the size shrinks to the nanoscale. The familiar mirror-like sheen of bulk metals is replaced by the bright, sharp, colorful plasmonic resonances of nanoparticles. The resonances of plasmonic metal nanoparticles are highly tunable throughout the visible spectrum, depending on the size, shape, local dielectric environment, and proximity to other optical resonances. Fundamental and applied research in the nanoscience community in the past few decades has sought to understand and exploit these phenomena for biological applications. In this work, discrete nanoparticle assemblies were produced through biomolecular interactions and studied at the single particle level with darkfield spectroscopy. Pairs of gold nanoparticles tethered by DNA were utilized as molecular rulers to study the dynamics of DNA bending by the restriction enzyme EcoRV. These results substantiated that nanoparticle rulers, deemed "plasmon rulers", could measure the dynamics of single biomolecules with high throughput, long lifetime, and high temporal resolution. To extend these concepts for live cell studies, a plasmon ruler comprised of peptide-linked gold nanoparticle satellites around a core particle was synthesized and utilized to optically follow cell signaling pathways in vivo at the single molecule level. The signal provided by these plasmon rulers allowed continuous observation of caspase-3 activation at the single molecule level in living cells for over 2 hours, unambiguously identifying early stage activation of caspase-3 in apoptotic cells. In the last section of this dissertation, an experimental and theoretical study of electomagnetic coupling in asymmetric metal nanoparticle dimers is presented. A "heterodimer" composed of a silver particle and a gold particle is observed to have a novel coupling between a plasmon mode (free electron oscillations) and an inter-band absorption process (bound electron transitions). The

  18. Tip110: Physical properties, primary structure, and biological functions.

    PubMed

    Whitmill, Amanda; Timani, Khalid Amine; Liu, Ying; He, Johnny J

    2016-03-15

    HIV-1 Tat-interacting protein of 110kDa (Tip110), also referred to as squamous cell carcinoma antigen recognized by T cells 3 (Sart3), p110 or p110(nrb), was initially identified as a cDNA clone (KIAA0156) without annotated functions. Over the past twenty years, several functions have been attributed to this protein. The proposed biological functions include roles for Tip110 in pre-mRNA splicing, gene transcription, stem cell biology, and development. Dysregulation of Tip110 is also a contributing factor in the development of cancer and other human diseases. It is clear that our understanding of this protein is rapidly evolving. In this review, we aimed to provide a summary of all the existing literature on this gene/protein and its proposed biological functions. PMID:26896687

  19. Predictive Models of Nanotoxicity: Relationship of Physicochemical Properties to Particle Movement Through Biological Barriers

    EPA Science Inventory

    Understanding the linkage between the physicochemical (PC) properties of nanoparticles (NP) and their activation of biological systems is poorly understood, yet fundamental to predicting nanotoxicity, idenitifying mode of actions and developing appropriate and effective regul...

  20. Biological activities and medicinal properties of Cajanus cajan (L) Millsp.

    PubMed Central

    Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K.

    2011-01-01

    Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. PMID:22247887

  1. Biological activities and medicinal properties of Cajanus cajan (L) Millsp.

    PubMed

    Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K

    2011-10-01

    Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. PMID:22247887

  2. Synthesis, transformations and biological properties of furo[2,3-b]pyridines

    NASA Astrophysics Data System (ADS)

    Sirakanyan, S. N.; Hovakimyan, A. A.; Noravyan, A. S.

    2015-04-01

    Data on furo[2,3-b]pyridines published in the last 15 years are integrated and analyzed for the first time. Information on the methods of synthesis, chemical transformations and biological action of these systems is described systematically. Particular attention is paid to the preparation and study of properties of polycondensed derivatives as the most promising and rapidly developing line of research of furo[2,3-b]pyridine chemistry. The biological properties of this class of compounds are discussed, and examples of furo[2,3-b]pyridines that exhibit high biological activities are given. The bibliography includes 88 references.

  3. Multiple biological properties of macelignan and its pharmacological implications.

    PubMed

    Paul, Saswati; Hwang, Jae Kwan; Kim, Hahn Young; Jeon, Won Kyung; Chung, ChiHye; Han, Jung-Soo

    2013-03-01

    Macelignan found in the nutmeg mace of Myristica fragrans obtains increasing attention as a new avenue in treating various diseases. Macelignan has been shown to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anti-cancer, anti-diabetes, and hepatoprotective activities; recently, it has also been shown to have neuroprotective activities. This review summarizes the current research on the biological effects of macelignan derived from M. fragrans, with emphasis on the importance in understanding and treating complex diseases such as cancer and Alzheimer's disease. PMID:23435944

  4. Biological properties of extracellular vesicles and their physiological functions.

    PubMed

    Yáñez-Mó, María; Siljander, Pia R-M; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E; Buzas, Edit I; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Cordeiro-da Silva, Anabela; Fais, Stefano; Falcon-Perez, Juan M; Ghobrial, Irene M; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H H; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Nolte-'t Hoen, Esther N M; Nyman, Tuula A; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; Del Portillo, Hernando A; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G; Vasconcelos, M Helena; Wauben, Marca H M; De Wever, Olivier

    2015-01-01

    In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system. PMID:25979354

  5. Biological properties of extracellular vesicles and their physiological functions

    PubMed Central

    Yáñez-Mó, María; Siljander, Pia R.-M.; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E.; Buzas, Edit I.; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Silva, Anabela Cordeiro-da; Fais, Stefano; Falcon-Perez, Juan M.; Ghobrial, Irene M.; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H. H.; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Hoen, Esther N.M. Nolte-‘t; Nyman, Tuula A.; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; del Portillo, Hernando A.; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N.; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G.; Vasconcelos, M. Helena; Wauben, Marca H. M.; De Wever, Olivier

    2015-01-01

    In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system. PMID:25979354

  6. Synthesis and biological properties of amino acids and peptides containing a tetrazolyl moiety

    NASA Astrophysics Data System (ADS)

    Popova, E. A.; Trifonov, R. E.

    2015-09-01

    Literature data published mainly in the last 15 years on the synthesis and biological properties of amino acid analogues and derivatives containing tetrazolyl moieties are analyzed. Tetrazolyl analogues and derivatives of amino acids and peptides are shown to be promising for medicinal chemistry. Being polynitrogen heterocyclic systems comprising four endocyclic nitrogen atoms, tetrazoles can behave as acids and bases and form strong hydrogen bonds with proton donors (more rarely, with acceptors). They have high metabolic stability and are able to penetrate biological membranes. The review also considers the synthesis and properties of linear and cyclic peptides based on modified amino acids incorporating a tetrazolyl moiety. A special issue is the discussion of the biological properties of tetrazole-containing amino acids and peptides, which exhibit high biological activity and can be used to design new drugs. The bibliography includes 200 references.

  7. Occult breast tumor reservoir: biological properties and clinical significance.

    PubMed

    Santen, Richard J; Yue, Wei; Heitjan, Daniel F

    2013-08-01

    Small, occult, undiagnosed breast cancers are found at autopsy in up to 15.6 % of women dying from unrelated causes with an average of 7 % from eight separate studies. The mammographic detection threshold of breast tumors ranges from 0.88 to 1.66 cm in diameter based on the patient's age. Tumor growth rates, expressed as "effective doubling times," vary from 10 to >700 days. We previously reported two models, based on iterative analysis of these parameters, to describe the biologic behavior of undiagnosed, occult breast tumors. Our models facilitate interpretation of the Women's Health Initiative (WHI) and antiestrogen breast cancer prevention studies. A nude mouse xenograft model was used to validate our assumption that breast tumors grow in a log-linear fashion. We then used our previously reported occult tumor growth (OTG) and computer-simulated tumor growth models to analyze various clinical trial data. Parameters used in the OTG model included a 200-day effective doubling time, 7 % prevalence of occult tumors, and 1.16 cm detection threshold. These models had been validated by comparing predicted with observed incidence of breast cancer in eight different populations of women. Our model suggests that menopausal hormone therapy with estrogens plus a progestogen (E + P) in the WHI trial primarily promoted the growth of pre-existing, occult lesions and minimally initiated de novo tumors. We provide a potential explanation for the lack of an increase in breast cancer incidence in the subgroup of women in the WHI who had not received E + P prior to randomization. This result may have reflected a leftward skew in the distribution of occult tumor doublings and insufficient time for stimulated tumors to reach the detection threshold. Our model predicted that estrogen alone reduced the incidence of breast cancer as a result of apoptosis. Understanding of the biology of occult tumors suggests that breast cancer "prevention" with antiestrogens or aromatase

  8. Terahertz vibrational properties of water nanoclusters relevant to biology.

    PubMed

    Johnson, Keith

    2012-01-01

    Water nanoclusters are shown from first-principles calculations to possess unique terahertz-frequency vibrational modes in the 1-6 THz range, corresponding to O-O-O "bending," "squashing," and "twisting" "surface" distortions of the clusters. The cluster molecular-orbital LUMOs are huge Rydberg-like "S," "P," "D," and "F" orbitals that accept an extra electron via optical excitation, ionization, or electron donation from interacting biomolecules. Dynamic Jahn-Teller coupling of these "hydrated-electron" orbitals to the THz vibrations promotes such water clusters as vibronically active "structured water" essential to biomolecular function such as protein folding. In biological microtubules, confined water-cluster THz vibrations may induce their "quantum coherence" communicated by Jahn-Teller phonons via coupling of the THz electromagnetic field to the water clusters' large electric dipole moments. PMID:23277672

  9. Chemical and biological properties related to toxicity of heated fats.

    PubMed

    Alexander, J C

    1981-01-01

    Heating of fats brings about measurable changes in their chemical and physical characteristics. Heat is applied in processing for food manufacture, such as during hydrogenation of oils with a catalyst, and in frying for meal preparation. Partially hydrogenated products generally contain substantial quantities of geometric and positional isomers of the original unsaturated fatty acids. During deep-fat frying, when the fat is used repeatedly, oxidative and thermal effects result in the formation of many volatile and nonvolatile products, some of which are potentially toxic, depending on the level of intake. Because of concern about the types of changes that take place in fats during oxidative and thermal deterioration and the effects the derivatives could have on the consumer, many chemical and biological studies have been carried out. Experimental findings indicate that any potential danger to the consumer is relative to the severity of the overall treatment of the fat. In some studies we evaluated biological effects on rats of trans fatty acid in the diet and of concentrates of fatty acid derivatives produced in thermally oxidized fats. trans-Octadecenoic acid changed the concentrations of the phospholipid classes in the liver lipids, and interfered with conversion of the essential n - 6 series of fatty acids to higher members. Compared to oleic acid, elaidic acid was preferentially incorporated into the phospholipids instead of the triacylglycerols and was also concentrated in the lipoprotein fractions. Administration of non-urea-adductable concentrates from thermally oxidized fats produced cellular damage in hearts, livers, and kidneys of the animals. Since even practical processing and frying conditions can produce some nutritionally undesirable products, a concerted effort should be made to minimize substantial accumulation of these in our dietary fats. PMID:7265292

  10. Phytochrome from Green Plants: Properties and biological Function

    SciTech Connect

    Quail, Peter H.

    2014-07-25

    Plants constantly monitor the light environment for informational light signals used to direct adaptational responses to the prevailing conditions. One major such response, the Shade-Avaoidance Response (SAR), triggered when plants sense the presence of competing neighbors, results in enhanced channeling of photosynthetically-fixed carbon into stem elongation at the expense of deposition in reproductive tissues. This response has been selected against in many modern food crops to ensure maximum edible yield (e.g. seeds). Converse enhancement of the SAR, with consequent increased carbon channeling into vegetative cellulose, could contribute to the generation of crops with improved yield of tissues suitable for cellulosic biofuel production. The signal for this response is light enriched in far-red wavelengths. This signal is produced by sunlight filtered through, or reflected from, neighboring vegetation, as a result of preferential depletion of red photons through chlorophyll absorption. The plant phytochrome (phy) photoreceptor system (predominantly phyB) senses this signal through its capacity to switch reversibly, in milliseconds, between two molecular states: the biologically inactive Pr (red-light-absorbing) and biologically active Pfr (far-red-light-absorbing) conformers. The photoequilibrium established between these two conformers in light-grown plants is determined by the ratio of red-to-far-red wavelengths in the incoming signal. The levels of Pfr then dictate the recipient plant’s growth response: high levels suppress elongation growth; low levels promote elongation growth. Studies on seedling deetiolation have advanced our understanding considerably in recent years, of the mechanism by which the photoactivated phy molecule transduces its signal into cellular growth responses. The data show that a subfamily of phy-interacting bHLH transcription factors (PIFs) promote skotomorphogenic seedling development in post-germinative darkness, but that the phy

  11. Fractal Scaling of Particle Size Distribution and Relationships with Topsoil Properties Affected by Biological Soil Crusts

    PubMed Central

    Gao, Guang-Lei; Ding, Guo-Dong; Wu, Bin; Zhang, Yu-Qing; Qin, Shu-Gao; Zhao, Yuan-Yuan; Bao, Yan-Feng; Liu, Yun-Dong; Wan, Li; Deng, Ji-Feng

    2014-01-01

    Background Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. Methodology/Principal Findings To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R2 = 0.494∼0.955, P<0.01). Conclusions/Significance Biological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions. PMID:24516668

  12. Manipulating lipid bilayer material properties using biologically active amphipathic molecules

    NASA Astrophysics Data System (ADS)

    Ashrafuzzaman, Md; Lampson, M. A.; Greathouse, D. V.; Koeppe, R. E., II; Andersen, O. S.

    2006-07-01

    Lipid bilayers are elastic bodies with properties that can be manipulated/controlled by the adsorption of amphipathic molecules. The resulting changes in bilayer elasticity have been shown to regulate integral membrane protein function. To further understand the amphiphile-induced modulation of bilayer material properties (thickness, intrinsic monolayer curvature and elastic moduli), we examined how an enantiomeric pair of viral anti-fusion peptides (AFPs)—Z-Gly-D-Phe and Z-Gly-Phe, where Z denotes a benzyloxycarbonyl group, as well as Z-Phe-Tyr and Z-D-Phe-Phe-Gly—alters the function of enantiomeric pairs of gramicidin channels of different lengths in planar bilayers. For both short and long channels, the channel lifetimes and appearance frequencies increase as linear functions of the aqueous AFP concentration, with no apparent effect on the single-channel conductance. These changes in channel function do not depend on the chirality of the channels or the AFPs. At pH 7.0, the relative changes in channel lifetimes do not vary when the channel length is varied, indicating that these compounds exert their effects primarily by causing a positive-going change in the intrinsic monolayer curvature. At pH 4.0, the AFPs are more potent than at pH 7.0 and have greater effects on the shorter channels, indicating that these compounds now change the bilayer elastic moduli. When AFPs of different anti-fusion potencies are compared, the rank order of the anti-fusion activity and the channel-modifying activity is similar, but the relative changes in anti-fusion potency are larger than the changes in channel-modifying activity. We conclude that gramicidin channels are useful as molecular force transducers to probe the influence of small amphiphiles upon lipid bilayer material properties.

  13. Biological residues define the ice nucleation properties of soil dust

    NASA Astrophysics Data System (ADS)

    Conen, F.; Morris, C. E.; Leifeld, J.; Yakutin, M. V.; Alewell, C.

    2011-06-01

    Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nuclei per unit mass active in the immersion freezing mode at -12 °C than montmorillonite, the most efficient pure clay mineral. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

  14. Antioxidant properties of violacein: possible relation on its biological function.

    PubMed

    Konzen, Marlon; De Marco, Daniela; Cordova, Clarissa A S; Vieira, Tiago O; Antônio, Regina V; Creczynski-Pasa, Tânia B

    2006-12-15

    Violacein, a violet pigment produced by Chromobacterium violaceum, has attracted much attention in recent literature due to its pharmacological properties. In this work, the antioxidant properties of violacein were investigated. The reactivity with oxygen and nitrogen reactive species and 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical, was evaluated. EPR studies were carried out to evaluate the reactivity with the hydroxyl radical. The action of violacein against lipid peroxidation in three models of lipid membranes, including rat liver microsomes, Egg and Soy bean phosphathidylcholine liposomes were also evaluated. The compound reacted with DPPH (IC(50)=30microM), nitric oxide (IC(50)=21microM), superoxide radicals (IC(50)=125microM) and decreased the hydroxyl radical EPR signal. The compound protected the studied membranes against peroxidation induced by reactive species in the micromolar range. The reconstitution of violacein into the membranes increased its antioxidant effect. These results indicate that the compound has strong antioxidant potential. Based on these results we suggest violacein plays an important role with the microorganism membrane in defense against oxidative stress. PMID:17011197

  15. [Lysozyme--occurrence in nature, biological properties and possible applications].

    PubMed

    Gajda, Ewa; Bugla-Płoskońska, Gabriela

    2014-01-01

    Lysozyme (LZ, muramidase, N-acetylmuramylhydrolase) is a protein occuring in animals, plants, bacteria and viruses. It can be found e.g. in granules of neutrophils, macrophages and in serum, saliva, milk, honey and hen egg white. The enzyme hydrolyzes the β-1,4 glycosidic bonds between N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) of cell wall peptidoglycan (PG) in Gram-positive and Gram-negative bacteria. In the animal kingdom, three muramidase types have been identified: the c-type (chicken type), the g-type (goose-type) and the i-type (invertebrates). The c-type LZ from hen egg white is a model for the study of protein structure and function. Muramidase shows bactericidal activity mainly against Gram-positive bacteria. Cytolytic activity against cells of Gram-negative bacteria has not been proved. Bacterial cells have developed defense mechanisms that allow them to avoid the action of LZ. They are based e.g. on the production of enzyme inhibitors or modification of the PG. LZ is one of the most studied enzymes and yet not all aspects characterizing this protein are fully understood. One of the most important unresolved issues concerning the biological function of LZ is the role of muramidase in the bactericidal action of serum against Gram-negative bacteria. In order to clarify the function of LZ, the enzyme is e.g. removed from the serum by adsorption onto bentonite (montmorillonite, MMT). By using X-ray diffraction techniques it has been shown that MMT after contact with the serum is delaminated. The problems associated with folding of muramidase and LZ participation in the development of amyloidoses also await explanation. PMID:25531714

  16. Cells release subpopulations of exosomes with distinct molecular and biological properties.

    PubMed

    Willms, Eduard; Johansson, Henrik J; Mäger, Imre; Lee, Yi; Blomberg, K Emelie M; Sadik, Mariam; Alaarg, Amr; Smith, C I Edvard; Lehtiö, Janne; El Andaloussi, Samir; Wood, Matthew J A; Vader, Pieter

    2016-01-01

    Cells release nano-sized membrane vesicles that are involved in intercellular communication by transferring biological information between cells. It is generally accepted that cells release at least three types of extracellular vesicles (EVs): apoptotic bodies, microvesicles and exosomes. While a wide range of putative biological functions have been attributed to exosomes, they are assumed to represent a homogenous population of EVs. We hypothesized the existence of subpopulations of exosomes with defined molecular compositions and biological properties. Density gradient centrifugation of isolated exosomes revealed the presence of two distinct subpopulations, differing in biophysical properties and their proteomic and RNA repertoires. Interestingly, the subpopulations mediated differential effects on the gene expression programmes in recipient cells. In conclusion, we demonstrate that cells release distinct exosome subpopulations with unique compositions that elicit differential effects on recipient cells. Further dissection of exosome heterogeneity will advance our understanding of exosomal biology in health and disease and accelerate the development of exosome-based diagnostics and therapeutics. PMID:26931825

  17. Cells release subpopulations of exosomes with distinct molecular and biological properties

    PubMed Central

    Willms, Eduard; Johansson, Henrik J.; Mäger, Imre; Lee, Yi; Blomberg, K. Emelie M.; Sadik, Mariam; Alaarg, Amr; Smith, C.I. Edvard; Lehtiö, Janne; EL Andaloussi, Samir; Wood, Matthew J.A.; Vader, Pieter

    2016-01-01

    Cells release nano-sized membrane vesicles that are involved in intercellular communication by transferring biological information between cells. It is generally accepted that cells release at least three types of extracellular vesicles (EVs): apoptotic bodies, microvesicles and exosomes. While a wide range of putative biological functions have been attributed to exosomes, they are assumed to represent a homogenous population of EVs. We hypothesized the existence of subpopulations of exosomes with defined molecular compositions and biological properties. Density gradient centrifugation of isolated exosomes revealed the presence of two distinct subpopulations, differing in biophysical properties and their proteomic and RNA repertoires. Interestingly, the subpopulations mediated differential effects on the gene expression programmes in recipient cells. In conclusion, we demonstrate that cells release distinct exosome subpopulations with unique compositions that elicit differential effects on recipient cells. Further dissection of exosome heterogeneity will advance our understanding of exosomal biology in health and disease and accelerate the development of exosome-based diagnostics and therapeutics. PMID:26931825

  18. Physicochemical and biological properties of biomimetic mineralo-protein nanoparticles formed spontaneously in biological fluids.

    PubMed

    Peng, Hsin-Hsin; Wu, Cheng-Yeu; Young, David; Martel, Jan; Young, Andrew; Ojcius, David M; Lee, Yu-Hsiu; Young, John D

    2013-07-01

    Recent studies indicate that mineral nanoparticles (NPs) form spontaneously in human body fluids. These biological NPs represent mineral precursors that are associated with ectopic calcifications seen in various human diseases. However, the parameters that control the formation of mineral NPs and their possible effects on human cells remain poorly understood. Here a nanomaterial approach to study the formation of biomimetic calcium phosphate NPs comparable to their physiological counterparts is described. Particle sizing using dynamic light scattering reveals that serum and ion concentrations within the physiological range yield NPs below 100 nm in diameter. While the particles are phagocytosed by macrophages in a size-independent manner, only large particles or NP aggregates in the micrometer range induce cellular responses that include production of mitochondrial reactive oxygen species, caspase-1 activation, and secretion of interleukin-1β (IL-1β). A comprehensive proteomic analysis reveals that the particle-bound proteins are similar in terms of their identity and number, regardless of particle size, suggesting that protein adsorption is independent of particle size and curvature. In conclusion, the conditions underlying the formation of mineralo-protein particles are similar to the ones that form in vivo. While mineral NPs do not activate immune cells, they may become pro-inflammatory and contribute to pathological processes once they aggregate and form larger mineral particles. PMID:23255529

  19. Evaluation of biological properties and clinical effectiveness of Aloe vera: A systematic review

    PubMed Central

    Radha, Maharjan H.; Laxmipriya, Nampoothiri P.

    2014-01-01

    Aloe vera (蘆薈 lú huì) is well known for its considerable medicinal properties. This plant is one of the richest natural sources of health for human beings coming. The chemistry of the plant has revealed the presence of more than 200 different biologically active substances. Many biological properties associated with Aloe species are contributed by inner gel of the leaves. Most research has been centralized on the biological activities of the various species of Aloe, which include antibacterial and antimicrobial activities of the nonvolatile constituents of the leaf gel. Aloe species are widely distributed in the African and the eastern European continents, and are spread almost throughout the world. The genus Aloe has more than 400 species but few, such as A. vera, Aloe ferox, and Aloe arborescens, are globally used for trade. A. vera has various medicinal properties such as antitumor, antiarthritic, antirheumatoid, anticancer, and antidiabetic properties. In addition, A. vera has also been promoted for constipation, gastrointestinal disorders, and for immune system deficiencies. However, not much convincing information is available on properties of the gel. The present review focuses on the detailed composition of Aloe gel, its various phytocomponents having various biological properties that help to improve health and prevent disease conditions. PMID:26151005

  20. Evaluation of biological properties and clinical effectiveness of Aloe vera: A systematic review.

    PubMed

    Radha, Maharjan H; Laxmipriya, Nampoothiri P

    2015-01-01

    Aloe vera ( lú huì) is well known for its considerable medicinal properties. This plant is one of the richest natural sources of health for human beings coming. The chemistry of the plant has revealed the presence of more than 200 different biologically active substances. Many biological properties associated with Aloe species are contributed by inner gel of the leaves. Most research has been centralized on the biological activities of the various species of Aloe, which include antibacterial and antimicrobial activities of the nonvolatile constituents of the leaf gel. Aloe species are widely distributed in the African and the eastern European continents, and are spread almost throughout the world. The genus Aloe has more than 400 species but few, such as A. vera, Aloe ferox, and Aloe arborescens, are globally used for trade. A. vera has various medicinal properties such as antitumor, antiarthritic, antirheumatoid, anticancer, and antidiabetic properties. In addition, A. vera has also been promoted for constipation, gastrointestinal disorders, and for immune system deficiencies. However, not much convincing information is available on properties of the gel. The present review focuses on the detailed composition of Aloe gel, its various phytocomponents having various biological properties that help to improve health and prevent disease conditions. PMID:26151005

  1. Bioactive glass/hydroxyapatite composites: mechanical properties and biological evaluation.

    PubMed

    Bellucci, Devis; Sola, Antonella; Anesi, Alexandre; Salvatori, Roberta; Chiarini, Luigi; Cannillo, Valeria

    2015-06-01

    Bioactive glass/hydroxyapatite composites for bone tissue repair and regeneration have been produced and discussed. The use of a recently developed glass, namely BG_Ca/Mix, with its low tendency to crystallize, allowed one to sinter the samples at a relatively low temperature thus avoiding several adverse effects usually reported in the literature, such as extensive crystallization of the glassy phase, hydroxyapatite (HA) decomposition and reaction between HA and glass. The mechanical properties of the composites with 80wt.% BG_Ca/Mix and 20wt.% HA are sensibly higher than those of Bioglass® 45S5 reference samples due to the presence of HA (mechanically stronger than the 45S5 glass) and to the thermal behaviour of the BG_Ca/Mix, which is able to favour the sintering process of the composites. Biocompatibility tests, performed with murine fibroblasts BALB/3T3 and osteocites MLO-Y4 throughout a multi-parametrical approach, allow one to look with optimism to the produced composites, since both the samples themselves and their extracts do not induce negative effects in cell viability and do not cause inhibition in cell growth. PMID:25842126

  2. [SEROLOGICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF PANTOEA AGGLOMERANS LIPOPOLYSACCHARIDES].

    PubMed

    Bulygina, T V; Yakovleva, L M; Brovarska, O S; Varbanets, L D

    2015-01-01

    The serological and phytotoxic properties of lipopolysaccharide (LPS) of plant pathogens--Pantoea agglomerans were studied. It is known that the thin variations in the structure of the O-specific polysaccharides determining serological specificity of gram- negative bacteria and used as a molecular basis of serological classification schemes. For P. agglomerans still does not exist a classification scheme based on serology specificity of their LPS. The results of cross serological tests demonstrate immunochemical heterogeneity of species P agglomerans. Only three strains of the 8488, 8490 and 7969 according to the agglutination of O-antigens and direct hemagglutination and inhibition direct hemagglutination can be attributed to a single serogroup. Other strains--each separate group, although some have a relationship. Compared with control plants under the influence of seed treatment of LPS in plants may be reduced, and in some cases increased root length, height and weight sprout, depending on the strain from which the selected LPS. Dive seedlings of tomatoes in the solutions of the studied preparations FSC caused the loss, and after some time, restore turgor. PMID:26829835

  3. [Photosensitizing properties of 3,3'-diethylthiacarbocyanine in biological media].

    PubMed

    Andreev, V M; Kuznetsova, N V; Shevelev, A B; Kudykina, Iu K; Guseva, M A; Epremian, A S; Lisitsyna, E S; Kuz'min, V A

    2014-01-01

    The objective of the study is elucidation of perspectives of 3,3'-diathylcarbocyaine application as a photosensitizer for curing viral infections by photodynamic therapy. Lipid-containing bacteriophage PM-2 of Pseudoalteromonas espejiana was used as a model. The testing was carried out at a special installation modeling photodynamic exposure conditions towards a non-fractionated phage lysate. 3,3'-DECC demonstrated a rapid photo-bleaching when added tothe phage lysate but not to water. The initial rate of PM-2 phage photoinactivation was proportional to the square concentration of the dye in the range of 0.5-9 μmol/L. This confirms a hypothesis that the dimer is the principal photochemically active form of the dye. An improved ability to form dimers was found in the dye in the phage lysate (10-folds better than in the water). The dye formed a stable adduct with the bacteriophage material. This adduct had an extinction maximum at λ(max) = 594 nm and demonstrated the properties of a polymer (sedimentation under a low-speed centrifugation). PMID:25775825

  4. Structure and mechanical properties of Saxidomus purpuratus biological shells.

    PubMed

    Yang, W; Zhang, G P; Zhu, X F; Li, X W; Meyers, M A

    2011-10-01

    The strength and fracture behavior of Saxidomus purpuratus shells were investigated and correlated with the structure. The shells show a crossed lamellar structure in the inner and middle layers and a fibrous/blocky and porous structure composed of nanoscaled particulates (~100 nm diameter) in the outer layer. It was found that the flexure strength and fracture mode are a function of lamellar organization and orientation. The crossed lamellar structure of this shell is composed of domains of parallel lamellae with approximate thickness of 200-600 nm. These domains have approximate lateral dimensions of 10-70 μm with a minimum of two orientations of lamellae in the inner and middle layers. Neighboring domains are oriented at specific angles and thus the structure forms a crossed lamellar pattern. The microhardness across the thickness was lower in the outer layer because of the porosity and the absence of lamellae. The tensile (from flexure tests) and compressive strengths were analyzed by means of Weibull statistics. The mean tensile (flexure) strength at probability of 50%, 80-105 MPa, is on the same order as the compressive strength (~50-150 MPa) and the Weibull moduli vary from 3.0 to 7.6. These values are significantly lower than abalone nacre, in spite of having the same aragonite structure. The lower strength can be attributed to a smaller fraction of the organic interlayer. The fracture path in the specimens is dominated by the orientation of the domains and proceeds preferentially along lamella boundaries. It also correlates with the color changes in the cross section of the shell. The cracks tend to undergo a considerable change in orientation when the color changes abruptly. The distributions of strengths, cracking paths, and fracture surfaces indicate that the mechanical properties of the shell are anisotropic with a hierarchical nature. PMID:21783161

  5. Effects of degree of carboxymethylation on physicochemical and biological properties of pachyman.

    PubMed

    Wang, Yongjiang; Mo, Qing; Li, Zenan; Lai, Hongwu; Lou, Jian; Liu, Shiwang; Mao, Jianwei

    2012-12-01

    Polysaccharides (pachyman) extracted from Poria cocos sclerotium were chemically modified by carboxymethylation and the effects on the structural and biological properties of the polysaccharides were investigated as a function of the degree of carboxymethylation. The degree of substitution (DS) of five carboxymethylated pachyman, coded as CMP1/CMP2/CMP3/CMP4/CMP5, was determined to be 0.44-0.88. The structures were confirmed by FT-IR and their weight-average molecular masses (Mw) were obtained by SEC-LLS. Experimental results showed that derivatives were effective in anti-oxidation and bile acid binding in a dose dependent way. Furthermore, their water solubility and biological activities were improved with the increase of DS. Therefore, results proved that the carboxymethylation of pachyman effectively enhanced their potential biological properties. PMID:22947452

  6. Long-term Tillage influences on soil carbon, nitrogen, physical, chemical, and biological properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term tillage influences physical, chemical, and biological properties of the soil environment and thereby crop production and quality. We evaluated the effect of long-term (>20 yrs) tillage no-till, spring till, and fall plus spring till under continuous spring wheat (Triticum aestivum L.) on s...

  7. Rheological Properties of a Biological Thermo-Hydrogel Produced from Soybean Oil Polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of a newly developed biological thermo-hydrogel made from vegetable oil were investigated. The material named HPSO-HG is a hydrolytic product of polymerized soybean oil (PSO). HPSO-HG exhibited viscoelastic behavior above 2% (wt.%) at room temperature and viscous fluid b...

  8. Rheological properties of a biological thermo-responsive hydrogel produced from soybean oil polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of a newly developed biological thermo-hydrogel made from vegetable oil were investigated. The material named HPSO-HG is a hydrolytic product of polymerized soybean oil (PSO). HPSO-HG is a thermo-responsive gel, and it exhibited viscoelastic behavior above 2% (wt.%) at roo...

  9. Rheological properties of a biological thermo-responsive hydrogel produced from soybean oil polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of a newly developed biological thermo-hydrogel made from vegetable oil were investigated. The material named HPSO-VI is a hydrolytic product of polymerized soybean oil (PSO). HPSO-VI exhibited viscoelastic behavior above 2% (wt. %) at room temperature and viscous fluid ...

  10. Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation

    USGS Publications Warehouse

    Hansen, Angela; Kraus, Tamara; Pellerin, Brian; Fleck, Jacob; Downing, Bryan D.; Bergamaschi, Brian

    2016-01-01

    Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commonly used optical properties and indices in DOM leached from peat soil, plants, and algae following biological and photochemical degradation to determine whether they provide unique signatures that can be linked to original DOM source. Changes in individual optical parameters varied by source material and process, with biodegradation and photodegradation often causing values to shift in opposite directions. Although values for different source materials overlapped at the end of the 111-day lab experiment, multivariate statistical analyses showed that unique optical signatures could be linked to original DOM source material even after degradation, with 17 optical properties determined by discriminant analysis to be significant (p<0.05) in distinguishing between DOM source and environmental processing. These results demonstrate that inferring the source material from optical properties is possible when parameters are evaluated in combination even after extensive biological and photochemical alteration.

  11. Biological Responses to Diesel Exhaust Particles (DEPs) Depend on the Physicochemical Properties of the DEPs

    PubMed Central

    Park, Eun-Jung; Roh, Jinkyu; Kang, Min-Sung; Kim, Soo Nam; Kim, Younghun; Choi, Sangdun

    2011-01-01

    Diesel exhaust particles (DEPs) are the main components of ambient particulate materials, including polyaromatic hydrocarbons (PAHs), n-PAHs, heavy metals, and gaseous materials. Many epidemiological, clinical, and toxicological studies have shown that ambient particles, including DEPs, are associated with respiratory disorders, such as asthma, allergic rhinitis, and lung cancer. However, the relationship between the biological response to DEPs and their chemical composition remains unclear. In this study, we investigated the physicochemical properties of DEPs before toxicological studies, and then administered a single intratracheal instillation of DEPs to mice. The mice were then killed 1, 7, 14 and 28 days after DEP exposure to observe the biological responses induced by DEPs over time. Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response. Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs. Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles. PMID:22039547

  12. Biological Properties of Single Chemical–DNA Adducts: A Twenty Year Perspective

    PubMed Central

    Delaney, James C.; Essigmann, John M.

    2010-01-01

    The genome and its nucleotide precursor pool are under sustained attack by radiation, reactive oxygen and nitrogen species, chemical carcinogens, hydrolytic reactions, and certain drugs. As a result, a large and heterogeneous population of damaged nucleotides forms in all cells. Some of the lesions are repaired, but for those that remain, there can be serious biological consequences. For example, lesions that form in DNA can lead to altered gene expression, mutation, and death. This perspective examines systems developed over the past 20 years to study the biological properties of single DNA lesions. PMID:18072751

  13. Mesenchymal Stem Cells Isolated from Adipose and Other Tissues: Basic Biological Properties and Clinical Applications

    PubMed Central

    Orbay, Hakan; Tobita, Morikuni; Mizuno, Hiroshi

    2012-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells that were initially isolated from bone marrow. However, subsequent research has shown that other adult tissues also contain MSCs. MSCs originate from mesenchyme, which is embryonic tissue derived from the mesoderm. These cells actively proliferate, giving rise to new cells in some tissues, but remain quiescent in others. MSCs are capable of differentiating into multiple cell types including adipocytes, chondrocytes, osteocytes, and cardiomyocytes. Isolation and induction of these cells could provide a new therapeutic tool for replacing damaged or lost adult tissues. However, the biological properties and use of stem cells in a clinical setting must be well established before significant clinical benefits are obtained. This paper summarizes data on the biological properties of MSCs and discusses current and potential clinical applications. PMID:22666271

  14. Predicting spiral wave patterns from cell properties in a model of biological self-organization

    NASA Astrophysics Data System (ADS)

    Geberth, Daniel; Hütt, Marc-Thorsten

    2008-09-01

    In many biological systems, biological variability (i.e., systematic differences between the system components) can be expected to outrank statistical fluctuations in the shaping of self-organized patterns. In principle, the distribution of single-element properties should thus allow predicting features of such patterns. For a mathematical model of a paradigmatic and well-studied pattern formation process, spiral waves of cAMP signaling in colonies of the slime mold Dictyostelium discoideum, we explore this possibility and observe a pronounced anticorrelation between spiral waves and cell properties (namely, the firing rate) and particularly a clustering of spiral wave tips in regions devoid of spontaneously firing (pacemaker) cells. Furthermore, we observe local inhomogeneities in the distribution of spiral chiralities, again induced by the pacemaker distribution. We show that these findings can be explained by a simple geometrical model of spiral wave generation.

  15. Electronic and Transport Properties of Quasi-1D Wires of Biological Molecules

    NASA Astrophysics Data System (ADS)

    Oetzel, Björn; Matthes, Lars; Tandetzky, Falk; Ortmann, Frank; Bechstedt, Friedhelm; Hannewald, Karsten

    2010-03-01

    In the search for organic materials with good charge-transport properties, artificial stacks of biological molecules are considered attractive candidates [1,2]. In this spirit, we present ab-initio DFT calculations of the structural, electronic, and quantum-transport properties of quasi-1D wires based on guanine and eumelanin molecules [3]. Hereby, a special focus is put on the results for the electronic bandwidths and the consequences for potential applications. [4pt] [1] R. di Felice et al., Phys. Rev. B 65, 045104 (2001) [0pt] [2] P. Meredith et al., Pigment Cell Res. 19, 572 (2006) [0pt] [3] B. Oetzel et al. (unpublished)

  16. [Study of some physical and biological properties of an endodontic sealer composed of calcium hydroxide].

    PubMed

    Birman, E G; Sampaio, J M; Magalhães, J; Sato, E

    1990-01-01

    The authors present a study of the physical and biological properties of a new endodontic cement known as Sealapex. In its composition the presence of calcium hydroxide is introduced in order to induce calcification of the periapical tissue. Our results using glass round cover slips implanted on the subcutaneous tissue of mice indicated a persistent foreign body reaction (60 days). The physical properties studied compared to N-Rickert ciment indicated, a decreased leakage. Adhesivity tests didn't give us significant values. Laboratorial studies and clinical trials are necessary to a complete acceptance of this new ciment in endodontic treatment. PMID:2135327

  17. Differentiation of celosia mosaic virus and asparagus virus 1 based on biological properties.

    PubMed

    Owolabi, A T; Proll, E

    2000-01-01

    An attempt was made to distinguish between celosia mosaic virus (CIMV) and asparagus virus 1 (AV-1) based on biological properties, which hitherto was obscured from serological data from previous work. The host range of AV-1 was found to be a subset of that of CIMV and AV-1 was transmitted by the aphid Myzus persicae which, on the other hand, did not transmit CIMV. No evidence of cross-protection was obtained between these two viruses. PMID:11155362

  18. Structure-property relationship of quinuclidinium surfactants--Towards multifunctional biologically active molecules.

    PubMed

    Skočibušić, Mirjana; Odžak, Renata; Štefanić, Zoran; Križić, Ivana; Krišto, Lucija; Jović, Ozren; Hrenar, Tomica; Primožič, Ines; Jurašin, Darija

    2016-04-01

    Motivated by diverse biological and pharmacological activity of quinuclidine and oxime compounds we have synthesized and characterized novel class of surfactants, 3-hydroxyimino quinuclidinium bromides with different alkyl chains lengths (CnQNOH; n=12, 14 and 16). The incorporation of non conventional hydroxyimino quinuclidinium headgroup and variation in alkyl chain length affects hydrophilic-hydrophobic balance of surfactant molecule and thereby physicochemical properties important for its application. Therefore, newly synthesized surfactants were characterized by the combination of different experimental techniques: X-ray analysis, potentiometry, electrical conductivity, surface tension and dynamic light scattering measurements, as well as antimicrobial susceptibility tests. Comprehensive investigation of CnQNOH surfactants enabled insight into structure-property relationship i.e., way in which the arrangement of surfactant molecules in the crystal phase correlates with their solution behavior and biologically activity. The synthesized CnQNOH surfactants exhibited high adsorption efficiency and relatively low critical micelle concentrations. In addition, all investigated compounds showed very potent and promising activity against Gram-positive and clinically relevant Gram-negative bacterial strains compared to conventional antimicrobial agents: tetracycline and gentamicin. The overall results indicate that bicyclic headgroup with oxime moiety, which affects both hydrophilicity and hydrophobicity of CnQNOH molecule in addition to enabling hydrogen bonding, has dominant effect on crystal packing and physicochemical properties. The unique structural features of cationic surfactants with hydroxyimino quinuclidine headgroup along with diverse biological activity have made them promising structures in novel drug discovery. Obtained fundamental understanding how combination of different functionalities in a single surfactant molecule affects its physicochemical

  19. Biological and genetic properties of the p53 null preneoplastic mammary epithelium

    NASA Technical Reports Server (NTRS)

    Medina, Daniel; Kittrell, Frances S.; Shepard, Anne; Stephens, L. Clifton; Jiang, Cheng; Lu, Junxuan; Allred, D. Craig; McCarthy, Maureen; Ullrich, Robert L.

    2002-01-01

    The absence of the tumor suppressor gene p53 confers an increased tumorigenic risk for mammary epithelial cells. In this report, we describe the biological and genetic properties of the p53 null preneoplastic mouse mammary epithelium in a p53 wild-type environment. Mammary epithelium from p53 null mice was transplanted serially into the cleared mammary fat pads of p53 wild-type BALB/c female to develop stable outgrowth lines. The outgrowth lines were transplanted for 10 generations. The outgrowths were ductal in morphology and progressed through ductal hyperplasia and ductal carcinoma in situ before invasive cancer. The preneoplastic outgrowth lines were immortal and exhibited activated telomerase activity. They are estrogen and progesterone receptor-positive, and aneuploid, and had various levels of tumorigenic potential. The biological and genetic properties of these lines are distinct from those found in most hyperplastic alveolar outgrowth lines, the form of mammary preneoplasia occurring in most traditional models of murine mammary tumorigenesis. These results indicate that the preneoplastic cell populations found in this genetically engineered model are similar in biological properties to a subset of precurser lesions found in human breast cancer and provide a unique model to identify secondary events critical for tumorigenicity and invasiveness.

  20. Effect of calcium hydroxide on mechanical strength and biological properties of bioactive glass.

    PubMed

    Shah, Asma Tufail; Batool, Madeeha; Chaudhry, Aqif Anwar; Iqbal, Farasat; Javaid, Ayesha; Zahid, Saba; Ilyas, Kanwal; Bin Qasim, Saad; Khan, Ather Farooq; Khan, Abdul Samad; Ur Rehman, Ihtesham

    2016-08-01

    In this manuscript for the first time calcium hydroxide (Ca(OH)2) has been used for preparation of bioactive glass (BG-2) by co-precipitation method and compared with glass prepared using calcium nitrate tetrahydrate Ca(NO3)2·4H2O (BG-1), which is a conventional source of calcium. The new source positively affected physical, biological and mechanical properties of BG-2. The glasses were characterized by Fourier transform infrared (FTIR), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA-DSC), BET surface area analysis and Knoop hardness. The results showed that BG-2 possessed relatively larger surface properties (100m(2)g(-1) surface area) as compared to BG-1 (78m(2)g(-1)), spherical morphology and crystalline phases (wollastonite and apatite) after sintering at lower than conventional temperature. These properties contribute critical role in both mechanical and biological properties of glasses. The Knoop hardness measurements revealed that BG-2 possessed much better hardness (0.43±0.06GPa at 680°C and 2.16±0.46GPa at 980°C) than BG-1 (0.24±0.01 at 680°C and 0.57±0.07GPA at 980°C) under same conditions. Alamar blue Assay and confocal microscopy revealed that BG-2 exhibited better attachment and proliferation of MG63 cells. Based on the improved biological properties of BG-2 as a consequent of novel calcium source selection, BG-2 is proposed as a bioactive ceramic for hard tissue repair and regeneration applications. PMID:27068802

  1. Structural Features and Biological Properties of Ellagitannins in Some Plant Families of the Order Myrtales

    PubMed Central

    Yoshida, Takashi; Amakura, Yoshiaki; Yoshimura, Morio

    2010-01-01

    Plant tannins, including hydrolysable and condensed varieties, are well known antioxidants in medicinal plants, foods, and edible fruits. Their diverse biological properties and potential for disease prevention have been demonstrated by various in vitro and in vivo assays. A number of ellagitannins, the largest group of hydrolysable tannins, have been isolated from dicotyledoneous angiosperms and characterized. This diverse class of tannins is sub-grouped into simple ellagitannins, C-glycosidic ellagitannins, complex tannins (condensates of C-glycosidic tannins with flavan-3-ol), and oligomers up to pentamers. This review outlines and describes the chemotaxonomic significance of structural features in various types of ellagitannins found in plants belonging to the Myrtaceae, Onagraceae, and Melastomataceae families, which are all included in the order Myrtales. Any biological activities that have been reported, including antitumor and antibacterial effects as well as enzyme inhibition, are also reviewed. PMID:20162003

  2. Microwave processed nanocrystalline hydroxyapatite: Simultaneous enhancement of mechanical and biological properties

    PubMed Central

    Bose, Susmita; Dasgupta, Sudip; Tarafder, Solaiman; Bandyopadhyay, Amit

    2010-01-01

    Despite excellent bioactivity of hydroxyapatite (HA) ceramics, poor mechanical strength has limited its applications primarily to coatings and other non-load bearing areas as bone grafts. Using synthesized HA nanopowder, dense compacts with grain sizes in nanometers to micrometers were processed via microwave sintering between 1000 and 1150 °C for 20 minutes. Here we demonstrate that mechanical properties, such as compressive strength, hardness and indentation fracture toughness of HA compacts increased with a decrease in grain size. HA with 168± 86 nm grain size showed the highest compressive strength of 395±42 MPa, hardness of 8.4±0.4 GPa and indentation fracture toughness of 1.9 ±0.2 MPam1/2. To study the in vitro biological properties, HA compacts with grain size between 168 nm and 1.16 µm were assessed for in vitro bone cell-materials interactions with human osteoblast cell line. Vinculin protein expression for cell attachment and bone cell proliferation using MTT assay showed surfaces with finer grains provided better bone cell-materials interactions than coarse grained samples. Our results indicate simultaneous improvements in mechanical and biological properties in microwave sintered HA compacts with nanoscale grain size. PMID:20230922

  3. Some reactions and properties of nitro radical-anions important in biology and medicine.

    PubMed Central

    Wardman, P

    1985-01-01

    Nitroaromatic compounds, ArNO2 have widespread actual or potential use in medicine and cancer therapy. There is direct proof that free-radical metabolites are involved in many applications, and an appreciation of the conceptual basis for their therapeutic differential; however, an understanding of the detailed mechanisms involved is lacking. Redox properties control most biological responses of nitro compounds, and the characteristics of the one-electron couple: ArNO2/ArNO2- are detailed. The "futile metabolism" of nitroaryl compounds characteristic of most aerobic nitroreductase systems reflects competition between natural radical-decay pathways and a one-electron transfer reaction to yield superoxide ion, O2-. Prototropic properties control the rate of radical decay, and redox properties control the rate of electron transfer to O2 or other acceptors. There are clear parallels in the chemistry of ArNO2- and O2-. While nitro radicals have frequently been invoked as damaging species, they are very unreactive (except as simple reductants). It seems likely that reductive metabolism of nitroaryl compounds, although generally involving nitro radical-anions as obligate intermediates (and this is required for therapeutic selectivity towards anaerobes), results in biological damage via reductive metabolites of higher reduction order than the one-electron product. PMID:3830700

  4. Soil Physicochemical and Biological Properties of Paddy-Upland Rotation: A Review

    PubMed Central

    Lv, Teng-Fei; Chen, Yong; Westby, Anthony P.; Ren, Wan-Jun

    2014-01-01

    Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

  5. Optimization of the Inverse Algorithm for Estimating the Optical Properties of Biological Materials Using Spatially-resolved Diffuse Reflectance Technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of the optical properties from intact biological materials based on diffusion approximation theory is a complicated inverse problem, and it requires proper implementation of inverse algorithm, instrumentation, and experiment. This work was aimed at optimizing the procedure of estimatin...

  6. Electrostatically self-assembled biodegradable microparticles from pseudoproteins and polysaccharide: fabrication, characterization, and biological properties.

    PubMed

    Potuck, Alicia N; Weed, Beth L; Leifer, Cynthia A; Chu, C C

    2015-02-01

    Electrostatically self-assembling hybrid microparticles derived from novel cationic unsaturated arginine-based poly(ester amide) polymers (UArg-PEA) and anionic hyaluronic acid (HA) were fabricated into sub-micron-sized particles in aqueous medium with subsequent UV crosslinking treatment to stabilize the structure. These hybrid microparticles were characterized for size, charge, viscosity, chemical structure, morphology, and biological properties. Depending on the feed ratio of cationic UArg-PEA to anionic HA, the crosslinked microparticles formed spherical structures of 0.772-22.08 μm in diameter, whereas the uncrosslinked microparticles formed a core with an outer petal-like structure of 2.49-15 μm in diameter. It was discovered that the morphological structure of the self-assembled microparticles had a profound influence on their biological properties. At a 1:1 feed ratio of UArg-PEA to HA, the uncrosslinked microparticles showed no cytotoxicity toward NIH 3T3 fibroblasts at concentrations up to 20 μg/mL, and the crosslinked particles exhibited no cytotoxicity at concentrations up to 10 μg/mL. The UArg-PEA/HA hybrid microparticles exhibited a significantly lower macrophage-induced proinflammatory response (via TNF-α) than that from a pure hyaluronic acid control while retaining the beneficial anti-inflammatory IL-10 production by HA. The UArg-PEA/HA microparticles also stimulated size-dependent induction of arginase activity. Therefore, self-assembling these two types of biomaterials in a favorable nontoxic aqueous environment, having complementary biological properties like those of the currently reported UArg-PEA/HA hybrid microparticles, may provide a new class of biomaterials to improve the overall tissue microenvironment for promoting wound healing. PMID:25531946

  7. Synthesis and biological properties of thiazole-analogues of pyochelin, a siderophore of Pseudomonas aeruginosa.

    PubMed

    Noël, Sabrina; Hoegy, Françoise; Rivault, Freddy; Rognan, Didier; Schalk, Isabelle J; Mislin, Gaëtan L A

    2014-01-01

    Pyochelin is a siderophore common to all strains of Pseudomonas aeruginosa utilized by this Gram-negative bacterium to acquire iron(III). FptA is the outer membrane transporter responsible of ferric-pyochelin uptake in P. aeruginosa. We describe in this Letter the synthesis and the biological properties ((55)Fe uptake, binding to FptA) of several thiazole analogues of pyochelin. Among them we report in this Letter the two first pyochelin analogues able to bind FptA without promoting any iron uptake in P. aeruginosa. PMID:24332092

  8. Physical, chemical, and biological properties of soils in the city of Mariupol, Ukraine

    NASA Astrophysics Data System (ADS)

    Shekhovtseva, O. G.; Mal'tseva, I. A.

    2015-12-01

    Physicochemical and biological properties of urbanized soils in the city of Mariupol have been considered in comparison with the background soils. The parametrical characteristics (abundance and biomass) of soil algal groups, the content of humus, the reaction of soil solution, the content of heavy metals, and the particle size distributions of soils under different anthropogenic impacts have been assessed. The physicochemical properties of soils developing under urboecosystem conditions affect the number of structure-forming species, biomass, and proportions of soil algae. According to the particle size distribution, urban soils are classified among the medium and heavy loamy soils with the predominance of the clay and coarse silt fractions. The fractions of physical clay and clay are of highest importance for the existence of algae. The accumulation of heavy metals in the surface horizons of soils can stimulate or inhibit the development of algae depending on the metal concentration.

  9. The effect of fibronectin on structural and biological properties of single walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Mottaghitalab, Fatemeh; Farokhi, Mehdi; Atyabi, Fatemeh; Omidvar, Ramin; Shokrgozar, Mohammad Ali; Sadeghizadeh, Majid

    2015-06-01

    Despite the attractive properties of carbon nanotubes (CNTs), cytoxicity and hydrophobicity are two main considerable features which limit their application in biomedical fields. It was well established that treating CNTs with extracellular matrix components could reduce these unfavourable characteristics. In an attempt to address these issues, fibronectin (FN) with different concentrations was loaded on single walled carbon nanotubes (SWCNTs) substrate. Scanning electron microscope, atomic force microscopy (AFM), contact angles and X-ray photoelectron spectroscopy (XPS) were preformed in order to characterize FN loaded SWCNTs substrates. According to XPS and AFM results, FN could interact with SWCNTs and for this, the hydrophilicity of SWCNTs was improved. Additionally, SWCNT modified with FN showed less cytotoxicity compared with neat SWCNT. Finally, FN was shown to act as an interesting extracellular component for enhancing the biological properties of SWCNT.

  10. A few nascent methods for measuring mechanical properties of the biological cell.

    SciTech Connect

    Thayer, Gayle Echo; de Boer, Maarten Pieter; Corvalan, Carlos; Corwin, Alex David; Campanella, Osvaldo H. (Purdue University, West Lafayette, IN); Nivens, David (Purdue University, West Lafayette, IN); Werely, Steven (Purdue University, West Lafayette, IN); Sumali, Anton Hartono; Koch, Steven John

    2006-01-01

    This report summarizes a survey of several new methods for obtaining mechanical and rheological properties of single biological cells, in particular: (1) The use of laser Doppler vibrometry (LDV) to measure the natural vibrations of certain cells. (2) The development of a novel micro-electro-mechanical system (MEMS) for obtaining high-resolution force-displacement curves. (3) The use of the atomic force microscope (AFM) for cell imaging. (4) The adaptation of a novel squeezing-flow technique to micro-scale measurement. The LDV technique was used to investigate the recent finding reported by others that the membranes of certain biological cells vibrate naturally, and that the vibration can be detected clearly with recent instrumentation. The LDV has been reported to detect motions of certain biological cells indirectly through the motion of a probe. In this project, trials on Saccharomyces cerevisiae tested and rejected the hypothesis that the LDV could measure vibrations of the cell membranes directly. The MEMS investigated in the second technique is a polysilicon surface-micromachined force sensor that is able to measure forces to a few pN in both air and water. The simple device consists of compliant springs with force constants as low as 0.3 milliN/m and Moire patterns for nanometer-scale optical displacement measurement. Fields from an electromagnet created forces on magnetic micro beads glued to the force sensors. These forces were measured and agreed well with finite element prediction. It was demonstrated that the force sensor was fully functional when immersed in aqueous buffer. These results show the force sensors can be useful for calibrating magnetic forces on magnetic beads and also for direct measurement of biophysical forces on-chip. The use of atomic force microscopy (AFM) for profiling the geometry of red blood cells was the third technique investigated here. An important finding was that the method commonly used for attaching the cells to a

  11. Wildfire effects on biological properties of soils in forest-steppe ecosystems of Russia

    NASA Astrophysics Data System (ADS)

    Maksimova, E.; Abakumov, E.

    2014-01-01

    Soils affected by forest wildfires in 2010 in Russia were studied on postfire and mature plots near the Togljatty city, Samara region. Soil biological properties and ash composition dynamics were investigated under the forest fire affect: a place of local forest fire, riding forest fire and unaffected site by fire-control (mature) during 3 yr of restoration. Soil samples were collected at 0-15 cm. Soil biological properties was measured by the fumigation method. The analytical data obtained shows that wildfires lead to serious changes in a soil profile and soil chemistry of upper horizons. Wildfires change a chemical composition of soil horizons and increase their ash-content. Fires lead to accumulation of biogenic elements' content (P and K) in the solum fine earth. Calcium content is increased as a result of fires that leads to an alkaline pH of the solum. The values of nutrients decreased as a result of leaching out with an atmospheric precipitation during the second year of restoration. Thus, when the upper horizons are burning the ash arriving on a soil surface enrich it with nutrients. The mature (unaffected by fire) soils is characterized by the greatest values of soil microbial biomass in the top horizon and, respectively, the bigger values of basal respiration whereas declining of the both parameters was revealed on postfire soils. Nevertheless this influence does not extend on depth more than 10 cm. Thus, fire affect on the soil were recognized in decreasing of microbiological activity.

  12. [Biological properties of L-asparaginase preparations from E. coli in cell cultures].

    PubMed

    Kondrat'eva, N A; Dobrynin, Ia V; Merkulov, M F

    1978-01-01

    Non-specific cytotoxicity and specific antitumor activity of 5 preparations of L-asparaginase from E. coli were studied. Two cell line, i.e. the asparagine-dependent (Berkitt lymphoma cells) and asparagin-independent (human ovary cancer cells) were used as the test-system. Incorporation of 3H-thimidine into DNA was the criterion of the preparation effect on the cells. Preparation I with the specific activity of 60-90 IU per 1 mg of protein obtained at the first stages of purification had high non-specific cytotoxicity. Preparation II obtained after further purification of preparation I, as well as preparation II without any stabilizer with the specific activity of 200 IU/mg were not inferior to the "Bayer" preparation by their biological properties. Addition of L-asparaginase to the preparation as a stabilizer of excessive glycine (preparation IV) increased its non-specific cytotoxicity and interfered with the study of its properties in the cell systems. Mannitol (preparation V) had no effect on the biological activity of L-asparaginase preparation. PMID:341799

  13. Synthesis and biological properties of caffeic acid-PNA dimers containing guanine.

    PubMed

    Gaglione, Maria; Malgieri, Gaetano; Pacifico, Severina; Severino, Valeria; D'Abrosca, Brigida; Russo, Luigi; Fiorentino, Antonio; Messere, Anna

    2013-01-01

    Caffeic acid (CA; 3,4-dihydroxycinnamic acid) is endowed with high antioxidant activity. CA derivatives (such as amides) have gained a lot of attention due to their antioxidative, antitumor and antimicrobial properties as well as stable characteristics. Caffeoyl-peptide derivatives showed different antioxidant activity depending on the type and the sequence of amino acid used. For these reasons, we decided to combine CA with Peptide Nucleic Acid (PNA) to test whether the new PNA-CA amide derivatives would result in an improvement or gain of CA's biological (i.e., antioxidant, cytotoxic, cytoprotective) properties. We performed the synthesis and characterization of seven dimer conjugates with various combinations of nucleic acid bases and focused NMR studies on the model compound ga-CA dimer. We demonstrate that PNA dimers containing guanine conjugated to CA exhibited different biological activities depending on composition and sequence of the nucleobases. The dimer ag-CA protected HepG2, SK-B-NE(2), and C6 cells from a cytotoxic dose of hydrogen peroxide (H₂O₂). PMID:23912270

  14. Physical Effects of Buckwheat Extract on Biological Membrane In Vitro and Its Protective Properties.

    PubMed

    Włoch, Aleksandra; Strugała, Paulina; Pruchnik, Hanna; Żyłka, Romuald; Oszmiański, Jan; Kleszczyńska, Halina

    2016-04-01

    Buckwheat is a valuable source of many biologically active compounds and nutrients. It has properties that reduce blood cholesterol levels, and so reduces the risk of atherosclerosis, seals the capillaries, and lowers blood pressure. The aim of the study was to determine quantitative and qualitative characteristics of polyphenols contained in extracts from buckwheat husks and stalks, the biological activity of the extracts, and biophysical effects of their interaction with the erythrocyte membrane, treated as a model of the cell. An analysis of the extract's composition has shown that buckwheat husk and stalk extracts are a rich source of polyphenolic compounds, the stalk extracts showing more compounds than the husk extract. The study allowed to determine the location which incorporated polyphenols occupy in the erythrocyte membrane and changes in the membrane properties caused by them. It was found that the extracts do not induce hemolysis of red blood cells, causing an increase in osmotic resistance of erythrocytes. They affect mainly the hydrophilic region by changing the degree of order of the polar heads of lipids, but do little to change the fluidity of the membrane and its hydration. The results showed also that polyphenolic substances included in the extracts well protect the membranes of red blood cells against oxidation and exhibit anti-inflammatory effect. PMID:26581904

  15. Can Carbon Nanotubes Deliver on Their Promise in Biology? Harnessing Unique Properties for Unparalleled Applications.

    PubMed

    Serpell, Christopher J; Kostarelos, Kostas; Davis, Benjamin G

    2016-04-27

    Carbon nanotubes (CNTs) are cylindrical sheets of hexagonally ordered carbon atoms, giving tubes with diameters on the order of a few nanometers and lengths typically in the micrometer range. They may be single- or multiwalled (SWCNTs and MWCNTs respectively). Since the seminal report of their synthesis in 1991, CNTs have fascinated scientists of all stripes. Physicists have been intrigued by their electrical, thermal, and vibrational potential. Materials scientists have worked on integrating them into ultrastrong composites and electronic devices, while chemists have been fascinated by the effects of curvature on reactivity and have developed new synthesis and purification techniques. However, to date no large-scale, real-life biotechnological CNT breakthrough has been industrially adopted and it is proving difficult to justify taking these materials forward into the clinic. We believe that these challenges are not the end of the story, but that a viable carbon nanotube biotechnology is one in which the unique properties of nanotubes bring about an effect that would be otherwise impossible. In this Outlook, we therefore seek to reframe the field by highlighting those biological applications in which the singular properties of CNTs provide some entirely new activity or biological effect as a pointer to "what could be". PMID:27163049

  16. Can Carbon Nanotubes Deliver on Their Promise in Biology? Harnessing Unique Properties for Unparalleled Applications

    PubMed Central

    2016-01-01

    Carbon nanotubes (CNTs) are cylindrical sheets of hexagonally ordered carbon atoms, giving tubes with diameters on the order of a few nanometers and lengths typically in the micrometer range. They may be single- or multiwalled (SWCNTs and MWCNTs respectively). Since the seminal report of their synthesis in 1991, CNTs have fascinated scientists of all stripes. Physicists have been intrigued by their electrical, thermal, and vibrational potential. Materials scientists have worked on integrating them into ultrastrong composites and electronic devices, while chemists have been fascinated by the effects of curvature on reactivity and have developed new synthesis and purification techniques. However, to date no large-scale, real-life biotechnological CNT breakthrough has been industrially adopted and it is proving difficult to justify taking these materials forward into the clinic. We believe that these challenges are not the end of the story, but that a viable carbon nanotube biotechnology is one in which the unique properties of nanotubes bring about an effect that would be otherwise impossible. In this Outlook, we therefore seek to reframe the field by highlighting those biological applications in which the singular properties of CNTs provide some entirely new activity or biological effect as a pointer to “what could be”. PMID:27163049

  17. Improving mechanical and biological properties of macroporous HA scaffolds through composite coatings.

    PubMed

    Zhao, J; Lu, X; Duan, K; Guo, L Y; Zhou, S B; Weng, J

    2009-11-01

    Interconnected porous hydroxyapatite (HA) scaffolds are widely used for bone repair and replacement, owing to their ability to support the adhesion, transfer, proliferation and differentiation of cells. In the present study, the polymer impregnation approach was adopted to produce porous HA scaffolds with three-dimensional (3D) porous structures. These scaffolds have an advantage of highly interconnected porosity (approximately 85%) but a drawback of poor mechanical strength. Therefore, the as-prepared HA scaffolds were lined with composite polymer coatings in order to improve the mechanical properties and retain its good bioactivity and biocompatibility at the same time. The composite coatings were based on poly(D,L-lactide) (PDLLA) polymer solutions, and contained single component or combination of HA, calcium sulfate (CS) and chondroitin sulfate (ChS) powders. The effects of composite coatings on scaffold porosity, microstructure, mechanical property, in vitro mineralizing behavior, and cell attachment of the resultant scaffolds were investigated. The results showed that the scaffolds with composite coatings resulted in significant improvement in both mechanical and biological properties while retaining the 3D interconnected porous structure. The in vitro mineralizing behaviors were mainly related to the compositions of CS and ChS powders in the composite coatings. Excellent cell attachments were observed on the pure HA scaffold as well as the three types of composite scaffolds. These composite scaffolds with improved mechanical properties and bioactivities are promising bone substitutes in tissue engineering fields. PMID:19679453

  18. Physico-chemical properties and biological effects of diesel and biomass particles.

    PubMed

    Longhin, Eleonora; Gualtieri, Maurizio; Capasso, Laura; Bengalli, Rossella; Mollerup, Steen; Holme, Jørn A; Øvrevik, Johan; Casadei, Simone; Di Benedetto, Cristiano; Parenti, Paolo; Camatini, Marina

    2016-08-01

    Diesel combustion and solid biomass burning are the major sources of ultrafine particles (UFP) in urbanized areas. Cardiovascular and pulmonary diseases, including lung cancer, are possible outcomes of combustion particles exposure, but differences in particles properties seem to influence their biological effects. Here the physico-chemical properties and biological effects of diesel and biomass particles, produced under controlled laboratory conditions, have been characterized. Diesel UFP were sampled from a Euro 4 light duty vehicle without DPF fuelled by commercial diesel and run over a chassis dyno. Biomass UFP were collected from a modern automatic 25 kW boiler propelled by prime quality spruce pellet. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of both diesel and biomass samples showed aggregates of soot particles, but in biomass samples ash particles were also present. Chemical characterization showed that metals and PAHs total content was higher in diesel samples compared to biomass ones. Human bronchial epithelial (HBEC3) cells were exposed to particles for up to 2 weeks. Changes in the expression of genes involved in xenobiotic metabolism were observed after exposure to both UFP already after 24 h. However, only diesel particles modulated the expression of genes involved in inflammation, oxidative stress and epithelial-to-mesenchymal transition (EMT), increased the release of inflammatory mediators and caused phenotypical alterations, mostly after two weeks of exposure. These results show that diesel UFP affected cellular processes involved in lung and cardiovascular diseases and cancer. Biomass particles exerted low biological activity compared to diesel UFP. This evidence emphasizes that the study of different emission sources contribution to ambient PM toxicity may have a fundamental role in the development of more effective strategies for air quality improvement. PMID:27194366

  19. Physical-chemical determinant properties of biological communities in continental semi-arid waters.

    PubMed

    da Rocha, Francisco Cleiton; de Andrade, Eunice Maia; Lopes, Fernando Bezerra; de Paula Filho, Francisco José; Filho, José Hamilton Costa; da Silva, Merivalda Doroteu

    2016-08-01

    Throughout human history, water has undergone changes in quality. This problem is more serious in dry areas, where there is a natural water deficit due to climatic factors. The aims of this study, therefore, were (i) to verify correlations between physical attributes, chemical attributes and biological metrics and (ii) from the biological attributes, to verify the similarity between different points of a body of water in a tropical semi-arid region. Samples were collected every 2 months, from July 2009 to July 2011, at seven points. Four physical attributes, five chemical attributes and four biological metrics were investigated. To identify the correlations between the physicochemical properties and the biological metrics, hierarchical cluster analysis (HCA) and canonical correlation analysis (CCA) were applied. Nine classes of phytoplankton were identified, with the predominance of species of cyanobacteria, and ten families of macroinvertebrates. The use of HCA resulted in the formation of three similar groups, showing that it was possible to reduce the number of sampling points when monitoring water quality with a consequent reduction in cost. Group I was formed from the waters at the high end of the reservoir (points P1, P2 and P3), group II by the waters from the middle third (points P4 and P5), and group III by the waters from the lower part of the reservoir (points P6 and P7). Richness of the phytoplanktons Cyanophyceae, Chorophyceae and Bacillariophyceae was the attribute which determined dissimilarity in water quality. Using CCA, it was possible to identify the spatial variability of the physicochemical attributes (TSS, TKN, nitrate and total phosphorus) that most influence the metrics of the macroinvertebrates and phytoplankton present in the water. Low macroinvertebrate diversity, with a predominance of indicator families for deterioration in water quality, and the composition of phytoplankton showing a predominance of cyanobacteria, suggests greater

  20. Extracellular polysaccharides from Ascomycota and Basidiomycota: production conditions, biochemical characteristics, and biological properties.

    PubMed

    Osińska-Jaroszuk, Monika; Jarosz-Wilkołazka, Anna; Jaroszuk-Ściseł, Jolanta; Szałapata, Katarzyna; Nowak, Artur; Jaszek, Magdalena; Ozimek, Ewa; Majewska, Małgorzata

    2015-12-01

    Fungal polysaccharides (PSs) are the subject of research in many fields of science and industry. Many properties of PSs have already been confirmed and the list of postulated functions continues to grow. Fungal PSs are classified into different groups according to systematic affinity, structure (linear and branched), sugar composition (homo- and heteropolysaccharides), type of bonds between the monomers (β-(1 → 3), β-(1 → 6), and α-(1 → 3)) and their location in the cell (cell wall PSs, exoPSs, and endoPSs). Exopolysaccharides (EPSs) are most frequently studied fungal PSs but their definition, classification, and origin are still not clear and should be explained. Ascomycota and Basidiomycota fungi producing EPS have different ecological positions (saprotrophic and endophytic, pathogenic or symbiotic-mycorrhizae fungi); therefore, EPSs play different biological functions, for example in the protection against environmental stress factors and in interactions with other organisms. EPSs obtained from Ascomycota and Basidiomycota fungal cultures are known for their antioxidant, immunostimulating, antitumor, and antimicrobial properties. The major objective of the presented review article was to provide a detailed description of the state-of-the-art knowledge of the effectiveness of EPS production by filamentous and yeast Ascomycota and Basidiomycota fungi and techniques of derivation of EPSs, their biochemical characteristics, and biological properties allowing comprehensive analysis as well as indication of similarities and differences between these fungal groups. Understanding the role of EPSs in a variety of processes and their application in food or pharmaceutical industries requires improvement of the techniques of their derivation, purification, and characterization. The detailed analyses of data concerning the derivation and application of Ascomycota and Basidiomycota EPSs can facilitate development and trace the direction of application of these EPSs

  1. A New Open-Source Toolbox for Estimating the Electrical Properties of Biological Tissues in the Terahertz Frequency band

    NASA Astrophysics Data System (ADS)

    Saviz, Mehrdad; Mogouon Toko, Lynda; Spathmann, Oliver; Streckert, Joachim; Hansen, Volkert; Clemens, Markus; Faraji-Dana, Reza

    2013-09-01

    The dielectric properties of biological tissues and their substructures at terahertz frequencies are needed for computational dosimetry, radiation safety regulation, and medical imaging, but experimental tissue data are only scarcely available for the terahertz band. Tissue properties can be theoretically predicted at terahertz frequencies if the tissue microstructure and composition, and the dielectric properties of several basic biological materials are known. This paper introduces a new open-source toolbox where a material database and many of the relevant formulas are implemented to facilitate related research. Several examples have been analyzed and successfully verified with experimental data from the literature.

  2. Mechanical and biological properties of chitosan/carbon nanotube nanocomposite films.

    PubMed

    Aryaei, Ashkan; Jayatissa, Ahalapitiya H; Jayasuriya, Ambalangodage C

    2014-08-01

    In this article, different concentrations of multiwalled carbon nanotube (MWCNT) were homogeneously dispersed throughout the chitosan (CS) matrix. A simple solvent-cast method was used to fabricate chitosan films with 0.1, 0.5, and 1% of MWCNT with the average diameter around 30 nm. The CS/MWCNT films were characterized for structural, viscous and mechanical properties with optical microscopy, wide-angle X-ray diffraction, Raman spectroscopy, tensile test machine, and microindentation testing machine. Murine osteoblasts were used to examine the cell viability and attachment of the nanocomposite films at two time points. In comparison to the pure chitosan film, the mechanical properties, including the tensile modulus and strength of the films, were greatly improved by increasing the percentage of MWCNT. Furthermore, adding MWCNT up to 1% increased the viscosity of the chitosan solution by 15%. However, adding MWCNT decreased the samples ductility and transparency. In biological point of view, no toxic effect on osteoblasts was observed in the presence of different percentages of MWCNT at day 3 and day 7. This investigation suggested MWCNT could be a promising candidate for improving chitosan mechanical properties without inducing remarkable cytotoxicity on bone cells. PMID:24108584

  3. Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties.

    PubMed

    Sant, Shilpa; Hwang, Chang Mo; Lee, Sang-Hoon; Khademhosseini, Ali

    2011-04-01

    Poly(glycerol sebacate) (PGS) is a biodegradable elastomer that has generated great interest as a scaffold material due to its desirable mechanical properties. However, the use of PGS in tissue engineering is limited by difficulties in casting micro- and nanofibrous structures, due to high temperatures and vacuum required for its curing and limited solubility of the cured polymer. In this paper, we developed microfibrous scaffolds made from blends of PGS and poly(ε-caprolactone) (PCL) using a standard electrospinning set-up. At a given PGS:PCL ratio, higher voltage resulted in significantly smaller fibre diameters (reduced from ∼4 µm to 2.8 µm; p < 0.05). Further increase in voltage resulted in the fusion of fibres. Similarly, higher PGS concentrations in the polymer blend resulted in significantly increased fibre diameter (p < 0.01). We further compared the mechanical properties of electrospun PGS:PCL scaffolds with those made from PCL. Scaffolds with higher PGS concentrations showed higher elastic modulus (EM), ultimate tensile strength (UTS) and ultimate elongation (UE) (p < 0.01) without the need for thermal curing or photocrosslinking. Biological evaluation of these scaffolds showed significantly improved HUVEC attachment and proliferation compared to PCL-only scaffolds (p < 0.05). Thus, we have demonstrated that simple blends of PGS prepolymer with PCL can be used to fabricate microfibrous scaffolds with mechanical properties in the range of a human aortic valve leaflet. PMID:20669260

  4. Biological and physical properties of autogenous vascularized fibular grafts in dogs

    SciTech Connect

    Goldberg, V.M.; Stevenson, S.; Shaffer, J.W.; Davy, D.; Klein, L.; Zika, J.; Field, G. )

    1990-07-01

    The biological and biomechanical properties of normal fibulae, fibulae that had had a sham operation, and both vascularized and non-vascularized autogenous grafts were studied in dogs at three months after the operation. The study was designed to quantify and correlate changes in these properties in orthotopic, stably fixed, weight-bearing grafts and to provide a baseline for additional studies of allografts. The grafts were eight centimeters long and internally fixed. The mechanical properties of the grafts were studied by torsional testing. Metabolic turnover of the grafts was evaluated by preoperative labeling of the dogs with 3H-tetracycline for resorption of bone mineral and with 3H-proline for turnover of collagen. Cortical bone area and porosity were measured. Postoperative formation of bone was evaluated by sequential labeling with fluorochrome. The vascularized grafts resembled the fibulae that had had a sham operation and those that had not had an operation with regard to the total number of osteons and the remodeling process, as measured both morphometrically and metabolically. The vascularized grafts were stronger and stiffer than the non-vascularized grafts and were not different from the bones that had had a sham operation. In contrast, the non-vascularized grafts were smaller, weaker, less stiff, and more porotic, had fewer osteons, and demonstrated increased turnover and resorption compared with the vascularized grafts, the bones that had had a sham operation, and the bones that had not been operated on.

  5. Mechanical and biological properties of chitosan/carbon nanotube nanocomposite films

    PubMed Central

    Aryaei, Ashkan; Jayatissa, Ahalapitiya H.; Jayasuriya, Ambalangodage C.

    2015-01-01

    In this paper, different concentrations of multi-walled carbon nanotube (MWCNT) were homogeneously dispersed throughout the chitosan (CS) matrix. A simple solvent-cast method was used to fabricate chitosan films with 0.1, 0.5, and 1% of MWCNT with the average diameter around 30 nm. The CS/MWCNT films were characterized for structural, viscous and mechanical properties with optical microscopy, wide-angle X-ray diffraction, Raman spectroscopy, tensile test machine, and microindentation testing machine. Murine osteoblasts were used to examine the cell viability and attachment of the nanocomposite films at two time points. In comparison to the pure chitosan film, the mechanical properties, including the tensile modulus and strength of the films were greatly improved by increasing the percentage of MWCNT. Furthermore, adding MWCNT up to 1% increased the viscosity of the chitosan solution by 15%. However, adding MWCNT decreased the samples ductility and transparency. In biological point of view, no toxic effect on osteoblasts was observed in the presence of different percentages of MWCNT at day 3 and day 7. This investigation suggested MWCNT could be a promising candidate for improving chitosan mechanical properties without inducing remarkable cytotoxicity on bone cells. PMID:24108584

  6. Hybrid PGS-PCL Microfibrous Scaffolds with Improved Mechanical and Biological Properties

    PubMed Central

    Sant, Shilpa; Hwang, Chang Mo; Lee, Sang-Hoon; Khademhosseini, Ali

    2010-01-01

    Poly(glycerol sebacate) (PGS) is a biodegradable elastomer that has generated great interest as a scaffold material due to its desirable mechanical properties. However, the use of PGS in tissue engineering is limited by the difficulties to cast micro and nanofibrous structures due to high temperatures and vacuum required for its curing and limited solubility of the cured polymer. In this paper, we developed microfibrous scaffolds made from blends of PGS and poly (ε-caprolactone) (PCL) by using standard electrospinning set up. At a given PGS:PCL ratio, higher voltage resulted in significantly smaller fiber diameters (from ~ 4 μm to 2.8 μm, p < 0.05). Further increase in voltage resulted in the fusion of fibers. Similarly, higher PGS concentrations in the polymer blend resulted in significantly increased fiber diameter (p < 0.01). We further compared mechanical properties of electrospun PGS:PCL scaffolds with those made from PCL. Scaffolds with higher PGS concentration showed higher elastic modulus (EM), ultimate tensile strength (UTS) and ultimate elongation (UE) (p < 0.01) without the need for thermal curing or photocrosslinking. Biological evaluation of these scaffolds showed significantly improved HUVEC attachment and proliferation compared to PCL-only scaffolds (p < 0.05). Thus, we have demonstrated that simple blends of PGS prepolymer with PCL can be used to fabricate microfibrous scaffolds with mechanical properties in the range of human aortic valve leaflet. PMID:20669260

  7. Effect of Gamma Irradiation on Structural and Biological Properties of a PLGA-PEG-Hydroxyapatite Composite

    PubMed Central

    Shahabi, Sima; Najafi, Farhood; Majdabadi, Abbas; Hooshmand, Tabassom; Haghbin Nazarpak, Masoumeh; Karimi, Batool

    2014-01-01

    Gamma irradiation is able to affect various structural and biological properties of biomaterials In this study, a composite of Hap/PLGA-PEG and their ingredients were submitted to gamma irradiation doses of 25 and 50 KGy. Various properties such as molecular weight (GPC), thermal behavior (DSC), wettability (contact angle), cell viability (MTT assay), and alkaline phosphatase activity were studied for the composites and each of their ingredients. The results showed a decrease in molecular weight of copolymer with no change in the glass transition and melting temperatures after gamma irradiation. In general gamma irradiation can increase the activation energy ΔH of the composites and their ingredients. While gamma irradiation had no effect on the wettability of copolymer samples, there was a significant decrease in contact angle of hydroxyapatite and composites with increase in gamma irradiation dose. This study showed an increase in biocompatibility of hydroxyapatite with gamma irradiation with no significant effect on cell viability in copolymer and composite samples. In spite of the fact that no change occurred in alkaline phosphatase activity of composite samples, results indicated a decrease in alkaline phosphatase activity in irradiated hydroxyapatites. These effects on the properties of PLGA-PEG-hydroxyapatite can enhance the composite application as a biomaterial. PMID:25574485

  8. Biological and physical properties of autogenous vascularized fibular grafts in dogs.

    PubMed

    Goldberg, V M; Stevenson, S; Shaffer, J W; Davy, D; Klein, L; Zika, J; Field, G

    1990-07-01

    The biological and biomechanical properties of normal fibulae, fibulae that had had a sham operation, and both vascularized and non-vascularized autogenous grafts were studied in dogs at three months after the operation. The study was designed to quantify and correlate changes in these properties in orthotopic, stably fixed, weight-bearing grafts and to provide a baseline for additional studies of allografts. The grafts were eight centimeters long and internally fixed. The mechanical properties of the grafts were studied by torsional testing. Metabolic turnover of the grafts was evaluated by preoperative labeling of the dogs with 3H-tetracycline for resorption of bone mineral and with 3H-proline for turnover of collagen. Cortical bone area and porosity were measured. Postoperative formation of bone was evaluated by sequential labeling with fluorochrome. The vascularized grafts resembled the fibulae that had had a sham operation and those that had not had an operation with regard to the total number of osteons and the remodeling process, as measured both morphometrically and metabolically. The vascularized grafts were stronger and stiffer than the non-vascularized grafts and were not different from the bones that had had a sham operation. In contrast, the non-vascularized grafts were smaller, weaker, less stiff, and more porotic, had fewer osteons, and demonstrated increased turnover and resorption compared with the vascularized grafts, the bones that had had a sham operation, and the bones that had not been operated on. PMID:2365713

  9. Possible prebiotic significance of polyamines in the condensation, protection, encapsulation, and biological properties of DNA

    NASA Technical Reports Server (NTRS)

    Baeza, I.; Ibanez, M.; Wong, C.; Chavez, P.; Gariglio, P.; Oro, J.

    1991-01-01

    Some properties of DNA condensed with spermidine have been compared with the properties of DNA condensed with Co3+(NH3)6 to determine whether condensation of DNA with these trivalent cations protects DNA against the action of DNase I and increases transcription and encapsulation of DNA into liposomes. It was shown that DNA condensed with Co3+(NH3)6 was resistant to the action of the endonuclease DNase I such as DNA condensed with spermidine was. However, DNA condensed with Co3+(NH3)6 was significantly less active in transcription with the E. coli RNA polymerase than DNA-spermidine condensed forms. In addition, it was demonstrated that both compacted forms of DNA were more efficiently encapsulated into neutral liposomes; however, negatively, charged liposomes were scarcely formed in the presence of DNA condensed with Co3+(NH3)6. These experiments and the well documented properties of polyamines increasing the resistance to radiations and hydrolysis of nucleic acids, as well as their biological activities, such as replication, transcription, and translation, together with the low concentration of Co3+ in the environment, lead us to propose spermidine as a plausible prebiotic DNA condensing agent rather than Co3+ and the basic proteins proposed by other authors. Then, we consider the possible role and relevance of the polyamine-nucleic acids complexes in the evolution of life.

  10. Effect of gamma irradiation on structural and biological properties of a PLGA-PEG-hydroxyapatite composite.

    PubMed

    Shahabi, Sima; Najafi, Farhood; Majdabadi, Abbas; Hooshmand, Tabassom; Haghbin Nazarpak, Masoumeh; Karimi, Batool; Fatemi, Seyyed Mostafa

    2014-01-01

    Gamma irradiation is able to affect various structural and biological properties of biomaterials In this study, a composite of Hap/PLGA-PEG and their ingredients were submitted to gamma irradiation doses of 25 and 50 KGy. Various properties such as molecular weight (GPC), thermal behavior (DSC), wettability (contact angle), cell viability (MTT assay), and alkaline phosphatase activity were studied for the composites and each of their ingredients. The results showed a decrease in molecular weight of copolymer with no change in the glass transition and melting temperatures after gamma irradiation. In general gamma irradiation can increase the activation energy ΔH of the composites and their ingredients. While gamma irradiation had no effect on the wettability of copolymer samples, there was a significant decrease in contact angle of hydroxyapatite and composites with increase in gamma irradiation dose. This study showed an increase in biocompatibility of hydroxyapatite with gamma irradiation with no significant effect on cell viability in copolymer and composite samples. In spite of the fact that no change occurred in alkaline phosphatase activity of composite samples, results indicated a decrease in alkaline phosphatase activity in irradiated hydroxyapatites. These effects on the properties of PLGA-PEG-hydroxyapatite can enhance the composite application as a biomaterial. PMID:25574485

  11. Insights on the Optical Properties of Estuarine DOM - Hydrological and Biological Influences.

    PubMed

    Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B H; Almeida, Adelaide

    2016-01-01

    Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems. PMID:27195702

  12. Insights on the Optical Properties of Estuarine DOM – Hydrological and Biological Influences

    PubMed Central

    Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B. H.

    2016-01-01

    Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems. PMID:27195702

  13. Self-Organisation, Thermotropic and Lyotropic Properties of Glycolipids Related to their Biological Implications

    PubMed Central

    Garidel, Patrick; Kaconis, Yani; Heinbockel, Lena; Wulf, Matthias; Gerber, Sven; Munk, Ariane; Vill, Volkmar; Brandenburg, Klaus

    2015-01-01

    Glycolipids are amphiphilic molecules which bear an oligo- or polysaccharide as hydrophilic head group and hydrocarbon chains in varying numbers and lengths as hydrophobic part. They play an important role in life science as well as in material science. Their biological and physiological functions are quite diverse, ranging from mediators of cell-cell recognition processes, constituents of membrane domains or as membrane-forming units. Glycolipids form an exceptional class of liquid-crystal mesophases due to the fact that their self-organisation obeys more complex rules as compared to classical monophilic liquid-crystals. Like other amphiphiles, the supra-molecular structures formed by glycolipids are driven by their chemical structure; however, the details of this process are still hardly understood. Based on the synthesis of specific glycolipids with a clearly defined chemical structure, e.g., type and length of the sugar head group, acyl chain linkage, substitution pattern, hydrocarbon chain lengths and saturation, combined with a profound physico-chemical characterisation of the formed mesophases, the principles of the organisation in different aggregate structures of the glycolipids can be obtained. The importance of the observed and formed phases and their properties are discussed with respect to their biological and physiological relevance. The presented data describe briefly the strategies used for the synthesis of the used glycolipids. The main focus, however, lies on the thermotropic as well as lyotropic characterisation of the self-organised structures and formed phases based on physico-chemical and biophysical methods linked to their potential biological implications and relevance. PMID:26464591

  14. Medicinal properties of mangiferin, structural features, derivative synthesis, pharmacokinetics and biological activities.

    PubMed

    Benard, Outhiriaradjou; Chi, Yuling

    2015-01-01

    The identification of biologically active and potentially therapeutically useful pharmacophores from natural products has been a long-term focus in the pharmaceutical industry. The recent emergence of a worldwide obesity and Type II diabetes epidemic has increased focus upon small molecules that can modulate energy metabolism, insulin sensitivity and fat biology. Interesting preliminary work done on mangiferin (MGF), the predominant constituent of extracts of the mango plant Mangifera indica L., portends potential for this pharmacophore as a novel parent compound for treating metabolic disorders. MGF is comprised of a C-glucosylated xanthone. Owing to the xanthone chemical structure, MGF has a redox active aromatic system and has antioxidant properties. MGF exerts varied and impressive metabolic effects in animals, improving metabolic disorders. For example we have discovered that MGF is a novel activator of the mammalian pyruvate dehydrogenase complex, leading to enhancement of carbohydrate utilization in oxidative metabolism, and leading to increased insulin sensitivity in animal models of obesity and insulin resistance. In addition, recent unbiased proteomics studies revealed that MGF upregulates proteins pivotal for mitochondrial bioenergetics and downregulates proteins controlling de novo lipogenesis in liver, helping to explain protective effects of MGF in prevention of liver steatosis. Several chemical studies have achieved synthesis of MGF, suggesting possible synthetic strategies to alter its chemical structure for development of structure-activity relationship (SAR) information. Ultimately, chemical derivatization studies could lead to the eventual development of novel therapeutics based upon the parent pharmacophore structure. Here we provide comprehensive review on chemical features of MGF, synthesis of its derivatives, its pharmacokinetics and biological activities. PMID:25827900

  15. Studies of optical and biological properties of terrestrial land cover using multispectral linear array technology

    NASA Technical Reports Server (NTRS)

    Barnes, W. L.; Salomonson, V. V.

    1984-01-01

    A series of experiments to study the optical and biological properties of terrestrial land cover are planned for late 1987 using a six-channel imaging spectroradiometer based on newly developed multispectral linear array (MLA) detector technology. Data from selected portions of the Sahel and rain forests of Africa and South America will be used to delineate biomass classes and estimate spherical albedos. A spatial resolution of 15 meters in the four visible-near IR channels and 30 meters in two shortwave IR channels, including a 'new' channel centered at 1.24 micrometers when combined with a spectral width of 20 nm for all channels, will be used to investigate possible improvements in land cover classification. Technology demonstrations include a test of data compression on data quality, the first spaceborne utilization of short wave infrared Schottky barrier Pd2Si detector arrays, and the use of close-butted, multi-array modules with attached spectral filters.

  16. Synthesis and Biological Properties of Porphyrin-Containing Polymeric Micelles with Different Sizes.

    PubMed

    Zhang, Jialiang; Zhang, Zhengkui; Yu, Bo; Wang, Chen; Wu, Wei; Jiang, Xiqun

    2016-03-01

    To understand the size effect of polymeric micelles on their biological properties, such as cellular uptake, biodistribution, tumor accumulation, and so on, we prepared a series of doxorubicin (DOX)-loaded protoporphyrin (PP)-poly(ε-caprolactone) (PCL)-poly(ethylene glycol) (PEG) micelles with different diameters (40, 70, 100, and 130 nm). The incorporation of the protoporphyrin moiety enhanced the stability of the micelles and provided luminescent capability that is useful in the investigation of the cellular uptake of the micelles by fluorescence imaging. The biodistributions of the micelles in mice bearing tumors were evaluated by near-infrared fluorescence imaging and DOX concentration measurements in different tissues. The in vitro and in vivo investigations demonstrated the pronounced dependence of the cellular uptake, biodistribution, and antitumor effectiveness of the micelles on their size. PMID:26894502

  17. Capturing mechanical properties of biological cells using coarse-grained modeling

    NASA Astrophysics Data System (ADS)

    Mao, Wenbin; Chang, Monique; Alexeev, Alexander

    2013-11-01

    Understanding cell mechanics is important for a variety of biomedical applications. Our goal is to develop a coarse-grained computational model that can properly capture the micromechanics of biological cells. The coarse-grained cell model includes an elastic shell enclosing a cross-linked polymer network and a viscous fluid representing, respectively, cell membrane, cytoskeleton, and cytoplasm. We use this model to investigate the mechanical response of cells to external forces and compare the results with the experimental AFM measurements. We systematically vary the properties and structure of the internal polymer network and the outer membrane to assess their influence on the cell mechanical responses. This model not only reveals interesting insights into the cell mechanics, but also provides a promising tool for investigation of motile and multicellular systems. Acknowledge financial support from NSF under Award No. 0932510.

  18. Production and Analysis of Biological Properties of Recombinant Human Apolipoprotein A-I.

    PubMed

    Ryabchenko, A V; Kotova, M V; Tverdohleb, N V; Knyazev, R A; Polyakov, L M

    2015-11-01

    Production of recombinant human apolipoprotein A-I (apoA-I) in E. coli cells is described and its biological properties are compared with those of natural protein. Recombinant apoA-I was isolated as a chimeric polypeptide and then processed to a mature form apoA-I (rapo-I). We studied the ability of the resulting protein to penetrate into hepatocyte nuclei and regulate the rate of DNA biosynthesis in complex with estriol. Penetration of rapoA-I conjugated with FITC into hepatocyte nuclei was demonstrated. rapoA-I-estriol and apoA-I-estriol complexes induced similar increase in DNA biosynthesis rate in isolated hepatocytes, which confi rms functional similarity of the obtained recombinant mature protein (rapoA-I) and native human apoA-I. PMID:26612626

  19. Understanding Oxadiazolothiazinone Biological Properties: Negative Inotropic Activity versus Cytochrome P450-Mediated Metabolism.

    PubMed

    Carosati, Emanuele; Cosimelli, Barbara; Ioan, Pierfranco; Severi, Elda; Katneni, Kasiram; Chiu, Francis C K; Saponara, Simona; Fusi, Fabio; Frosini, Maria; Matucci, Rosanna; Micucci, Matteo; Chiarini, Alberto; Spinelli, Domenico; Budriesi, Roberta

    2016-04-14

    We present a series of oxadiazolothiazinones, selective inotropic agents on isolated cardiac tissues, devoid of chronotropy and vasorelaxant activity. Functional and binding data for the precursor of the series (compound 1) let us hypothesize LTCC blocking activity and the existence of a recognition site specific for this scaffold. We synthesized and tested 22 new derivatives: introducing a para-methoxyphenyl at C-8 led to compound 12 (EC50 = 0.022 μM), twice as potent as its para-bromo analogue (1). For 10 analogues, we extended the characterization of the biological properties by including the assessment of metabolic stability in human liver microsomes and cytochrome P450 inhibition potential. We observed that the methoxy group led to active compounds with low metabolic stability and high CYP inhibition, whereas the protective effect of bromine resulted in enhanced metabolic stability and reduced CYP inhibition. Thus, we identified two para-bromo benzothiazino-analogues as candidates for further studies. PMID:26962886

  20. Ultrastable gold substrates: Properties of a support for high-resolution electron cryomicroscopy of biological specimens

    PubMed Central

    Russo, Christopher J.; Passmore, Lori A.

    2016-01-01

    Electron cryomicroscopy (cryo-EM) allows structure determination of a wide range of biological molecules and specimens. All-gold supports improve cryo-EM images by reducing radiation-induced motion and image blurring. Here we compare the mechanical and electrical properties of all-gold supports to amorphous carbon foils. Gold supports are more conductive, and have suspended foils that are not compressed by differential contraction when cooled to liquid nitrogen temperatures. These measurements show how the choice of support material and geometry can reduce specimen movement by more than an order of magnitude during low-dose imaging. We provide methods for fabrication of all-gold supports and preparation of vitrified specimens. We also analyse illumination geometry for optimal collection of high resolution, low-dose data. Together, the support structures and methods herein can improve the resolution and quality of images from any electron cryomicroscope. PMID:26592474

  1. On the influence of microscopic architecture elements to the global viscoelastic properties of soft biological tissue

    NASA Astrophysics Data System (ADS)

    Posnansky, Oleg P.

    2014-12-01

    In this work we introduce a 2D minimal model of random scale-invariant network structures embedded in a matrix to study the influence of microscopic architecture elements on the viscoelastic behavior of soft biological tissue. Viscoelastic properties at a microscale are modeled by a cohort of basic elements with varying complexity integrated into multi-hierarchic lattice obeying self-similar geometry. It is found that this hierarchy of structure elements yields a global nonlinear frequency dependent complex-valued shear modulus. In the dynamic range of external frequency load, the modeled shear modulus proved sensitive to the network concentration and viscoelastic characteristics of basic elements. The proposed model provides a theoretical framework for the interpretation of dynamic viscoelastic parameters in the context of microstructural variations under different conditions.

  2. Biological and immunological properties of the carboxyl terminus of staphylococcal enterotoxin C1.

    PubMed

    Bohach, G A; Handley, J P; Schlievert, P M

    1989-01-01

    Comparisons of recently published primary sequences of staphylococcal and streptococcal pyrogenic toxins prompted an evaluation of biological and immunological properties of the C terminus of staphylococcal enterotoxin C1. The 59 N-terminal amino acids were deleted from the toxin by digestion with trypsin. The resulting fragment (Mr, 20,659) contained the remaining 180 C-terminal residues. This fragment (Trp F1) consisted of two polypeptide chains (Trp F1a and Trp F1b) linked by cysteine residues. Trp F1 was mitogenic, pyrogenic, and enhanced susceptibility of rabbits to lethal endotoxin shock. In addition, this fragment contained at least one antigenic epitope that cross-reacted with enterotoxin B. PMID:2909489

  3. Force per cross-sectional area from molecules to muscles: a general property of biological motors

    PubMed Central

    Meyer-Vernet, Nicole

    2016-01-01

    We propose to formally extend the notion of specific tension, i.e. force per cross-sectional area—classically used for muscles, to quantify forces in molecular motors exerting various biological functions. In doing so, we review and compare the maximum tensions exerted by about 265 biological motors operated by about 150 species of different taxonomic groups. The motors considered range from single molecules and motile appendages of microorganisms to whole muscles of large animals. We show that specific tensions exerted by molecular and non-molecular motors follow similar statistical distributions, with in particular, similar medians and (logarithmic) means. Over the 1019 mass (M) range of the cell or body from which the motors are extracted, their specific tensions vary as Mα with α not significantly different from zero. The typical specific tension found in most motors is about 200 kPa, which generalizes to individual molecular motors and microorganisms a classical property of macroscopic muscles. We propose a basic order-of-magnitude interpretation of this result. PMID:27493785

  4. ADP ribosylation of human neutrophil peptide-1 regulates its biological properties.

    PubMed

    Paone, Gregorino; Wada, Akihiro; Stevens, Linda A; Matin, Abul; Hirayama, Toshiya; Levine, Rodney L; Moss, Joel

    2002-06-11

    In human airways, epithelial cells lining the lumen and intraluminal cells (e.g., polymorphonuclear cells) participate in the innate immune response. These cells secrete or express on their surfaces arginine-specific ADP ribosyltransferases. Defensins, antimicrobial proteins secreted by immune cells, are arginine-rich, leading us to hypothesize that ADP ribosylation could modify their biological activities. We found that an arginine-specific ADP ribosyltransferase-1 present on airway epithelial cells modifies Arg-14 of alpha defensin-1. ADP-ribosylated defensin-1 had decreased antimicrobial and cytotoxic activities but still stimulated T cell chemotaxis and IL-8 release from A549 cells. Further, ADP-ribosylated defensin-1 inhibited cytotoxic and antimicrobial activities of unmodified defensin-1. We identified ADP-ribosylated defensin-1 in bronchoalveolar lavage fluid from smokers but not from nonsmokers, confirming its existence in vivo. Thus, airway mono-ADP-ribosyltransferases could have an important regulatory role in the innate immune response through modification of alpha defensin-1 and perhaps other basic molecules, with alteration of their biological properties. PMID:12060767

  5. Structural parameters, molecular properties, and biological evaluation of some terpenes targeting Schistosoma mansoni parasite.

    PubMed

    Mafud, Ana C; Silva, Marcos P N; Monteiro, Daniela C; Oliveira, Maria F; Resende, João G; Coelho, Mayara L; de Sousa, Damião P; Mendonça, Ronaldo Z; Pinto, Pedro L S; Freitas, Rivelilson M; Mascarenhas, Yvonne P; de Moraes, Josué

    2016-01-25

    The use of natural products has a long tradition in medicine, and they have proven to be an important source of lead compounds in the development of new drugs. Among the natural compounds, terpenoids present broad-spectrum activity against infective agents such as viruses, bacteria, fungi, protozoan and helminth parasites. In this study, we report a biological screening of 38 chemically characterized terpenes from different classes, which have a hydroxyl group connected by hydrophobic chain or an acceptor site, against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. In vitro bioassays revealed that 3,7-dimethyl-1-octanol (dihydrocitronellol) (10) was the most active terpene (IC50 values of 13-52 μM) and, thus, we investigated its antischistosomal activity in greater detail. Confocal laser scanning microscopy revealed that compound 10 induced severe tegumental damage in adult schistosomes and a correlation between viability and tegumental changes was observed. Furthermore, we compared all the inactive compounds with dihydrocitronellol structurally by using shape and charge modeling. Lipophilicity (miLogP) and other molecular properties (e.g. molecular polar surface area, molecular electrostatic potential) were also calculated. From the 38 terpenes studied, compound 10 is the one with the greatest flexibility, with a sufficient apolar region by which it may interact in a hydrophobic active site. In conclusion, the integration of biological and chemical analysis indicates the potential of the terpene dihydrocitronellol as an antiparasitic agent. PMID:26697994

  6. Inactivation of the antibacterial and cytotoxic properties of silver ions by biologically relevant compounds.

    PubMed

    Mulley, Geraldine; Jenkins, A Tobias A; Waterfield, Nicholas R

    2014-01-01

    There has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells). Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC) if Ag+ and thiols are added in a 1:1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec) and Acticoat (Smith & Nephew) to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants). We believe our findings are essential for the effective design and testing of antimicrobial silver coatings. PMID:24728271

  7. Inactivation of the Antibacterial and Cytotoxic Properties of Silver Ions by Biologically Relevant Compounds

    PubMed Central

    Mulley, Geraldine; Jenkins, A. Tobias A.; Waterfield, Nicholas R.

    2014-01-01

    There has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells). Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC) if Ag+ and thiols are added in a 1∶1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec) and Acticoat (Smith & Nephew) to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants). We believe our findings are essential for the effective design and testing of antimicrobial silver coatings. PMID:24728271

  8. Optical and biological properties of transparent nanocrystalline hydroxyapatite obtained through spark plasma sintering.

    PubMed

    Li, Zhong; Thompson, Brianna C; Dong, Zhili; Khor, Khiam Aik

    2016-12-01

    Transparent bioceramics have attracted a large amount of research interest as they facilitate direct observation of biointerfacial reactions. Thus far, attempts to achieve transparent hydroxyapatite have been focused on augmenting the sintering pressure and/or extending the sintering duration. This study aims at fabricating transparent HA using a direct and fast spark plasma sintering process with appropriate starting powder and moderate sintering pressure. Three types of raw powder, namely micro-spheres, nano-rods and nano-spheres, were sintered to investigate the optical and biological properties of the compacted pellets. It was found that in terms of transparency, the micro-sphere pellet sintered at 1000°C stood out with an in-line transmittance as high as 84% achieved at 1300nm for a 2mm thick sample. In addition, pellets fabricated from micro-spheres demonstrated the highest cell viability in in vitro biological tests with L929 cells. Living cells cultured on a transparent micro-sphere pellet could be directly and clearly observed by light microscopy. It is thus concluded that the micro-sphere powder is the most desirable raw material to manufacture transparent hydroxyapatite because it could enable dense pellets with notably high transparency and outstanding in vitro biocompatibility to be readily obtained. PMID:27612791

  9. Chemical Diversity and Biological Properties of Secondary Metabolites from Sea Hares of Aplysia Genus

    PubMed Central

    Pereira, Renato B.; Andrade, Paula B.; Valentão, Patrícia

    2016-01-01

    The marine environment is an important source of structurally-diverse and biologically-active secondary metabolites. During the last two decades, thousands of compounds were discovered in marine organisms, several of them having inspired the development of new classes of therapeutic agents. Marine mollusks constitute a successful phyla in the discovery of new marine natural products (MNPs). Over a 50-year period from 1963, 116 genera of mollusks contributed innumerous compounds, Aplysia being the most studied genus by MNP chemists. This genus includes 36 valid species and should be distinguished from all mollusks as it yielded numerous new natural products. Aplysia sea hares are herbivorous mollusks, which have been proven to be a rich source of secondary metabolites, mostly of dietary origin. The majority of secondary metabolites isolated from sea hares of the genus Aplysia are halogenated terpenes; however, these animals are also a source of compounds from other chemical classes, such as macrolides, sterols and alkaloids, often exhibiting cytotoxic, antibacterial, antifungal, antiviral and/or antifeedant activities. This review focuses on the diverse structural classes of secondary metabolites found in Aplysia spp., including several compounds with pronounced biological properties. PMID:26907303

  10. Lipopolysaccharide of Yersinia pestis, the Cause of Plague: Structure, Genetics, Biological Properties

    PubMed Central

    Knirel, Y.A.; Anisimov, A.P.

    2012-01-01

    The present review summarizes data pertaining to the composition and structure of the carbohydrate moiety (core oligosaccharide) and lipid component (lipid A) of the various forms of lipopolysaccharide (LPS), one of the major pathogenicity factors ofYersinia pestis, the cause of plague. The review addresses the functions and the biological significance of genes for the biosynthesis of LPS, as well as the biological properties of LPS in strains from various intraspecies groups ofY. pestis and their mutants, including the contribution of LPS to the resistance of bacteria to factors of the innate immunity of both insect-vectors and mammal-hosts. Special attention is paid to temperature-dependent variations in the LPS structure, their genetic control and roles in the pathogenesis of plague. The evolutionary aspect is considered based on a comparison of the structure and genetics of the LPS ofY. pestis and other enteric bacteria, including otherYersinia species. The prospects of development of live plague vaccines created on the basis ofY. pestis strains with the genetically modified LPS are discussed. PMID:23150803

  11. Chemical Diversity and Biological Properties of Secondary Metabolites from Sea Hares of Aplysia Genus.

    PubMed

    Pereira, Renato B; Andrade, Paula B; Valentão, Patrícia

    2016-02-01

    The marine environment is an important source of structurally-diverse and biologically-active secondary metabolites. During the last two decades, thousands of compounds were discovered in marine organisms, several of them having inspired the development of new classes of therapeutic agents. Marine mollusks constitute a successful phyla in the discovery of new marine natural products (MNPs). Over a 50-year period from 1963, 116 genera of mollusks contributed innumerous compounds, Aplysia being the most studied genus by MNP chemists. This genus includes 36 valid species and should be distinguished from all mollusks as it yielded numerous new natural products. Aplysia sea hares are herbivorous mollusks, which have been proven to be a rich source of secondary metabolites, mostly of dietary origin. The majority of secondary metabolites isolated from sea hares of the genus Aplysia are halogenated terpenes; however, these animals are also a source of compounds from other chemical classes, such as macrolides, sterols and alkaloids, often exhibiting cytotoxic, antibacterial, antifungal, antiviral and/or antifeedant activities. This review focuses on the diverse structural classes of secondary metabolites found in Aplysia spp., including several compounds with pronounced biological properties. PMID:26907303

  12. Effects of cellular homeostatic intrinsic plasticity on dynamical and computational properties of biological recurrent neural networks.

    PubMed

    Naudé, Jérémie; Cessac, Bruno; Berry, Hugues; Delord, Bruno

    2013-09-18

    Homeostatic intrinsic plasticity (HIP) is a ubiquitous cellular mechanism regulating neuronal activity, cardinal for the proper functioning of nervous systems. In invertebrates, HIP is critical for orchestrating stereotyped activity patterns. The functional impact of HIP remains more obscure in vertebrate networks, where higher order cognitive processes rely on complex neural dynamics. The hypothesis has emerged that HIP might control the complexity of activity dynamics in recurrent networks, with important computational consequences. However, conflicting results about the causal relationships between cellular HIP, network dynamics, and computational performance have arisen from machine-learning studies. Here, we assess how cellular HIP effects translate into collective dynamics and computational properties in biological recurrent networks. We develop a realistic multiscale model including a generic HIP rule regulating the neuronal threshold with actual molecular signaling pathways kinetics, Dale's principle, sparse connectivity, synaptic balance, and Hebbian synaptic plasticity (SP). Dynamic mean-field analysis and simulations unravel that HIP sets a working point at which inputs are transduced by large derivative ranges of the transfer function. This cellular mechanism ensures increased network dynamics complexity, robust balance with SP at the edge of chaos, and improved input separability. Although critically dependent upon balanced excitatory and inhibitory drives, these effects display striking robustness to changes in network architecture, learning rates, and input features. Thus, the mechanism we unveil might represent a ubiquitous cellular basis for complex dynamics in neural networks. Understanding this robustness is an important challenge to unraveling principles underlying self-organization around criticality in biological recurrent neural networks. PMID:24048833

  13. Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction

    PubMed Central

    Periaswamy Sivagnanam, Saravana; Yin, Shipeng; Choi, Jae Hyung; Park, Yong Beom; Woo, Hee Chul; Chun, Byung Soo

    2015-01-01

    The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process. PMID:26035021

  14. Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction.

    PubMed

    Sivagnanam, Saravana Periaswamy; Yin, Shipeng; Choi, Jae Hyung; Park, Yong Beom; Woo, Hee Chul; Chun, Byung Soo

    2015-06-01

    The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone-methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process. PMID:26035021

  15. How preconditioning affects the measurement of poro-viscoelastic mechanical properties in biological tissues.

    PubMed

    Hosseini, Sayyed Mohsen; Wilson, Wouter; Ito, Keita; van Donkelaar, Corrinus C

    2014-06-01

    It is known that initial loading curves of soft biological tissues are substantially different from subsequent loadings. The later loading curves are generally used for assessing the mechanical properties of a tissue, and the first loading cycles, referred to as preconditioning, are omitted. However, slow viscoelastic phenomena related to fluid flow or collagen viscoelasticity are initiated during these first preconditioning loading cycles and may persist during the actual data collection. When these data are subsequently used for fitting of material properties, the viscoelastic phenomena that occurred during the initial cycles are not accounted for. The aim of the present study is to explore whether the above phenomena are significant for articular cartilage, by evaluating the effect of such time-dependent phenomena by means of computational modeling. Results show that under indentation, collagen viscoelasticity dominates the time-dependent behavior. Under UC, fluid-dependent effects are more important. Interestingly, viscoelastic and poroelastic effects may act in opposite directions and may cancel each other out in a stress-strain curve. Therefore, equilibrium may be apparent in a stress-strain relationship, even though internally the tissue is not in equilibrium. Also, the time-dependent effects of viscoelasticity and poroelasticity may reinforce each other, resulting in a sustained effect that lasts longer than suggested by their individual effects. Finally, the results illustrate that data collected from a mechanical test may depend on the preconditioning protocol. In conclusion, preconditioning influences the mechanical response of articular cartilage significantly and therefore cannot be neglected when determining the mechanical properties. To determine the full viscoelastic and poroelastic properties of articular cartilage requires fitting to both preconditioning and post-preconditioned loading cycles. PMID:23864393

  16. Physico-chemical properties of hydrophilic and amphiphilic crosslinked systems that influence biological responses

    NASA Astrophysics Data System (ADS)

    Ejiasi, Angel

    The effect of physical, chemical, and biological cues on the behavior of smooth muscle cells (SMCs) and attachment of marine organisms was investigated. Both hydrophilic and amphiphilic crosslinked polymer networks with varying chemical and mechanical properties were used to direct biological responses. Poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels were fabricated with tunable mechanical properties by varying the di-functional monomer concentration in the feed composition. Amphiphilic hydrogels composed of 2-hydroxyethyl methacrylate (HEMA), 1,3-bis(3-methacryloxypropyl)tetrakis(trimethylsiloxy)disiloxane (MPTSDS), and tris(trimethylsiloxy)-3-methacryloxypropylsilane (TRIS) were copolymerized using ultraviolet (UV) light and a photo-initiator. Hydrogels prepared with varying concentration of di-functional monomer, MPTSDS, exhibited an order of magnitude difference in elastic moduli. Not only were the bulk material properties influenced by the crosslinking agent concentration in the feed composition, but the surface properties (i.e., contact angle and hysteresis) were influenced as well. Modulus (E) has been reported to be positively correlated with the settlement of marine organisms. However, this was not the case for the amphiphilic gels tested against biomolecules and marine organisms. Stiffer gels inhibited fouling of proteins and marine organism, Ulva linza, to a greater extent than the softer gels. Furthermore, the network structure, in regards to the molecular weight between crosslinks Mc, was found to have a greater influence on fouling. A strong correlation was observed between protein adsorption and Mc of the amphiphilic crosslinked networks compared to just the modulus and surface energy (Upsilon) alone. A higher correlation was also obtained between Mc and Ulva sporeling biomass than between sporeling biomass and elastic modulus E, exhibiting R² value of 0.98 and 0.38, respectively. The percent removal of sporeling biomass growth was shown to be

  17. Comparative analysis of housekeeping and tissue-selective genes in human based on network topologies and biological properties.

    PubMed

    Yang, Lei; Wang, Shiyuan; Zhou, Meng; Chen, Xiaowen; Zuo, Yongchun; Sun, Dianjun; Lv, Yingli

    2016-06-01

    Housekeeping genes are genes that are turned on most of the time in almost every tissue to maintain cellular functions. Tissue-selective genes are predominantly expressed in one or a few biologically relevant tissue types. Benefitting from the massive gene expression microarray data obtained over the past decades, the properties of housekeeping and tissue-selective genes can now be investigated on a large-scale manner. In this study, we analyzed the topological properties of housekeeping and tissue-selective genes in the protein-protein interaction (PPI) network. Furthermore, we compared the biological properties and amino acid usage between these two gene groups. The results indicated that there were significant differences in topological properties between housekeeping and tissue-selective genes in the PPI network, and housekeeping genes had higher centrality properties and may play important roles in the complex biological network environment. We also found that there were significant differences in multiple biological properties and many amino acid compositions. The functional genes enrichment and subcellular localizations analysis was also performed to investigate the characterization of housekeeping and tissue-selective genes. The results indicated that the two gene groups showed significant different enrichment in drug targets, disease genes and toxin targets, and located in different subcellular localizations. At last, the discriminations between the properties of two gene groups were measured by the F-score, and expression stage had the most discriminative index in all properties. These findings may elucidate the biological mechanisms for understanding housekeeping and tissue-selective genes and may contribute to better annotate housekeeping and tissue-selective genes in other organisms. PMID:26897376

  18. [Biological properties of the isolate of Trichinella spp. from a jackal in the North-Caucasian Region].

    PubMed

    Odoevskaia, I M; Kurnosova, O P; Klinkov, A V; Bocharova, M M

    2009-01-01

    The biological properties of the isolate from Trichinella from ajackal in the North-Caucasian Region of the Russian Federation were studied. The jackal's muscle tissue showed two Trichinella species preserving their genetic isolation during 5 passages on mice. Oval capsules containing live larvae (on day 90 after infection) in the rat muscles corresponds to the conventional description of the species Trichinella spiralis in their morphometric and biological properties. The morphological data, biological properties, and poor adaptation of round capsule-enclosed parasites to rats indirectly show their affiliation to the other Trichinella species--T. native or T. britovi. There was a negative test for outbred albino rat muscle Trichinella resistance to freezing, which, might be associated with the poor adaptation of this Trichinella isolate to this species of rodents. PMID:19830913

  19. Biological properties of carbon/carbon implant composites with unique manufacturing processes.

    PubMed

    Wang, Guo-Hui; Yu, Shu; Zhu, Shai-Hong; Gao, Chang-Qing; Liu, Yong; Miu, Yun-Liang; Huang, Bo-Yun

    2009-12-01

    The goal was to manufacture carbon/carbon (C/C) composites through a unique procedure with improved biocompatibility and reduced debris release. C/C composites were prepared by chemical vapor deposition, and their biological properties were analyzed. With regard to mechanical properties, compressive strength/modulus was 219.1 MPa/9.72 GPa, flexural strength/modulus was 121.63 MPa/21.9 GPa, and interlaminar sheer was 15.13 GPa. Biocompatibility testing revealed: (1) the extract liquid from the C/C composites had no effect on cell proliferation; (2) the extract had no impact on micronucleus frequency as compared with the control groups (P > 0.05); (3) in vivo, there was mild tissue inflammation after implantation within the first 2 weeks, but there was no significant difference compared with the control group (P > 0.05); (4) the implants were well integrated into the host tissue, and debris was limited. The tested samples have excellent biocompatibilities and reduced release of debris. The demonstrated changes in manufacturing procedures are promising. PMID:19593650

  20. Biological properties and biodegradation studies of chitosan biofilms plasticized with PEG and glycerol.

    PubMed

    Kammoun, Maher; Haddar, Manel; Kallel, Tasnim Kossentini; Dammak, Mohamed; Sayari, Adel

    2013-11-01

    Chitosan biofilms, prepared by casting method at various percentage of plasticizer (PEG and glycerol), were evaluated for their biological, structural and thermal properties. The addition of PEG at 30% (w/w) and glycerol at 10% (w/w) to chitosan has increased the antioxidant activity of biofilm with the percentages of 22 and 26%, respectively. The increase of ferric reducing power was noted for the mixtures of chitosan-PEG (70-30) and chitosan-GLY (75-25). Additionally, the antibacterial properties of several biofilms were tested against E. coli and S. aureus. Biofilms with 70-30 and 90-10 blends ratio of chitosan-PEG and chitosan-GLY showed the best inhibitory effect against E. coli and S. aureus with 12 and 27%, respectively. All biofilms were degraded in compost in liquid and the addition of plasticizer PEG to chitosan increased his biodegradability with a value of BOD5 about 2.33 O2/mg CO. FT-IR spectra showed that the addition of plasticizer promoted the interactions through hydrogen bonding as reflected on the shifting of main peaks but there is no effect on biodegradation. PMID:24076201

  1. An optimized molecular inclusion complex of diferuloylmethane: enhanced physical properties and biological activity

    PubMed Central

    Tan, Qunyou; Li, Yi; Wu, Jianyong; Mei, Hu; Zhao, Chunjing; Zhang, Jingqing

    2012-01-01

    Objective The purpose of this study was to explore and evaluate the enhanced physical properties and biological activity of a molecular inclusion complex (MICDH) comprising diferuloylmethane (DFM) and hydroxypropyl-β-cyclodextrin. Methods The preparation conditions of MICDH were optimized using an orthogonal experimental design. The solubility, in vitro release and model fitting, microscopic morphology, molecular structure simulation, anti-lung cancer activity, and action mechanism of MICDH were evaluated. Results The solubility of DFM was improved 4400-fold upon complexation with hydroxypropyl-β-cyclodextrin. The release rate of DFM was significantly higher from MICDH than from free DFM. MICDH exhibited higher antitumor activity against human lung adenocarcinoma A549 cells than free DFM. More cells were arrested in the S/G2 phase of the cell cycle or were induced to undergo apoptosis when treated with MICDH than when treated with free DFM. Furthermore, increased reactive oxygen species and intracellular calcium ion levels and decreased mitochondrial membrane potential were observed in cells treated with MICDH. Conclusion MICDH markedly improved the physical properties and antitumor activity of DFM. MICDH may prove to be a preferred alternative to free DFM as a formulation for DFM delivery in lung cancer treatment. PMID:23091376

  2. Biological Properties and Characterization of ASL50 Protein from Aged Allium sativum Bulbs.

    PubMed

    Kumar, Suresh; Jitendra, Kumar; Singh, Kusum; Kapoor, Vaishali; Sinha, Mou; Xess, Immaculata; Das, Satya N; Sharma, Sujata; Singh, Tej P; Dey, Sharmistha

    2015-08-01

    Allium sativum is well known for its medicinal properties. The A. sativum lectin 50 (ASL50, 50 kDa) was isolated from aged A. sativum bulbs and purified by gel filtration chromatography on Sephacryl S-200 column. Agar well diffusion assay were used to evaluate the antimicrobial activity of ASL50 against Candida species and bacteria then minimal inhibitory concentration (MIC) was determined. The lipid A binding to ASL50 was determined by surface plasmon resonance (SPR) technology with varying concentrations. Electron microscopic studies were done to see the mode of action of ASL50 on microbes. It exerted antimicrobial activity against clinical Candida isolates with a MIC of 10-40 μg/ml and clinical Pseudomonas aeruginosa isolates with a MIC of 10-80 μg/ml. The electron microscopic study illustrates that it disrupts the cell membrane of the bacteria and cell wall of fungi. It exhibited antiproliferative activity on oral carcinoma KB cells with an IC50 of 36 μg/ml after treatment for 48 h and induces the apoptosis of cancer cells by inducing 2.5-fold higher caspase enzyme activity than untreated cells. However, it has no cytotoxic effects towards HEK 293 cells as well as human erythrocytes even at higher concentration of ASL50. Biological properties of ASL50 may have its therapeutic significance in aiding infection and cancer treatments. PMID:26043852

  3. Biologically relevant photoacoustic imaging phantoms with tunable optical and acoustic properties.

    PubMed

    Vogt, William C; Jia, Congxian; Wear, Keith A; Garra, Brian S; Joshua Pfefer, T

    2016-10-01

    Established medical imaging technologies such as magnetic resonance imaging and computed tomography rely on well-validated tissue-simulating phantoms for standardized testing of device image quality. The availability of high-quality phantoms for optical-acoustic diagnostics such as photoacoustic tomography (PAT) will facilitate standardization and clinical translation of these emerging approaches. Materials used in prior PAT phantoms do not provide a suitable combination of long-term stability and realistic acoustic and optical properties. Therefore, we have investigated the use of custom polyvinyl chloride plastisol (PVCP) formulations for imaging phantoms and identified a dual-plasticizer approach that provides biologically relevant ranges of relevant properties. Speed of sound and acoustic attenuation were determined over a frequency range of 4 to 9 MHz and optical absorption and scattering over a wavelength range of 400 to 1100 nm. We present characterization of several PVCP formulations, including one designed to mimic breast tissue. This material is used to construct a phantom comprised of an array of cylindrical, hemoglobin-filled inclusions for evaluation of penetration depth. Measurements with a custom near-infrared PAT imager provide quantitative and qualitative comparisons of phantom and tissue images. Results indicate that our PVCP material is uniquely suitable for PAT system image quality evaluation and may provide a practical tool for device validation and intercomparison. PMID:26886681

  4. Lunar Rhythms In Forestry Traditions - Lunar-Correlated Phenomena In Tree Biology And Wood Properties

    NASA Astrophysics Data System (ADS)

    Zürcher, Ernst

    For more than 2000 years, certain forestry practices and rules regarding tree felling have been carried out in observance to Moon cycles. A general review of the different types of rules followed (known in Europe and on other continents and stemming from both written sources and current practitioners) shows that special timber uses are mentioned in relation to a specific felling date which supposedly ensures advantageous wood properties. These empirical forestry traditions apply to a range of wood uses as diverse as building timber, shingles, wooden chimneys, fuel wood, resonance wood for harmony tables of violins, cheese-boxes, barrels and ploughs. In each of these cases, felling at the ``right date'' is thought to be an important factor to ensure the required properties of the product. Moreover, the rafting of timber used to be limited to certain days of the Moon cycle, when the water was supposed to carry the wood in the best way. The second part presents scientific studies concerned, on the one hand, with ``Moon phases'' factor. They deal with elements of tree biology such as germination and initial growth of tropical trees (where strong and systematic variations and their complicating aspects have been observed), insect attacks on trees and reversible fluctuations of stem diameters. On the other hand, some works concentrate on wood properties and the relation between wood and water. They deal with the durability of wood, with systematic density variations after kiln-drying and with variations in the compression strength of the corresponding samples. An overview tries to find a common link between empirical practices and the scientific results.

  5. Spectroscopic properties of gold nanoparticles at the single-particle level in biological environments.

    PubMed

    Estrada, Laura C; Gratton, Enrico

    2012-03-01

    Labeling cells and tissues with fluorescent probes, such as organic dyes and quantum dots (Qdots) is a widespread and successful technique for studying molecular dynamics both in vitro and in vivo. However, those probes usually suffer from undesirable photophysical/photochemical processes, such as blinking and photobleaching, limiting their utilization. The main challenges in fluorescent probe design are to improve their absorption/emission properties, and to provide higher stability against photobleaching. In the last few years, metallic nanoparticles (NPs) of various sizes, shapes, and compositions have been used as a new alternative for cellular microscopy. This is in part because-unlike common organic dyes and Qdots-metallic NPs do not bleach or blink upon continuous illumination, are extremely stable, very bright, and their luminescence spans over the visible spectrum. These characteristics make them attractive contrast agents for cell imaging both in vitro and in vivo. For these reasons, the emission of metallic NPs in bulk solutions has already been extensively characterized. In contrast with bulk experiments, where billions of molecules are measured simultaneously, single-particle techniques allow the observation of characteristics and dynamical processes otherwise hidden in the measured average. A full understanding of the photophysical properties of the NPs is critical when they are used for single-molecule applications. Photophysical processes can be a source of artifacts if they are not interpreted accordingly, and thus a careful characterization of these labels at the single-particle level became crucial for the correct interpretation of the experimental results. Herein, we study some of their unique optical properties at the single-particle level and show examples that illustrate their intrinsic heterogeneity when used in biological environments. PMID:22298327

  6. Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests

    PubMed Central

    Ayres, Edward; Steltzer, Heidi; Berg, Sarah; Wallenstein, Matthew D.; Simmons, Breana L.; Wall, Diana H.

    2009-01-01

    Background Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. Methodology/Principal Findings We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N) concentration and lowest lignin∶N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin∶N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not

  7. Comparative study of the biological properties of Trypanosoma cruzi I genotypes in a murine experimental model.

    PubMed

    Cruz, Lissa; Vivas, Angie; Montilla, Marleny; Hernández, Carolina; Flórez, Carolina; Parra, Edgar; Ramírez, Juan David

    2015-01-01

    Chagas disease is an endemic zoonosis in Latin America and caused by the parasite Trypanosoma cruzi. This kinetoplastid displays remarkable genetic variability, allowing its classification into six Discrete Typing Units (DTUs) from TcI to TcVI. T. cruzi I presents the broadest geographical distribution in the continent and has been associated to severe forms of cardiomyopathies. Recently, a particular genotype associated to human infections has been reported and named as TcIDOM (previously named TcIa-b). This genotype shows to be clonal and adapted to the domestic cycle but so far no studies have determined the biological properties of domestic (TcIDOM) and sylvatic TcI strains (previously named TcIc-e). Hence, the aim of this study was to untangle the biological features of these genotypes in murine models. We infected ICR-CD1 mice with five TcI strains (two domestic, two sylvatic and one natural mixture) and determined the course of infection during 91 days (acute and chronic phase of the disease) in terms of parasitemia, tissue tropism, immune response (IgG titers) and tissue invasion by means of histopathology studies. Statistically significant differences were observed in terms of parasitemia curves and prepatent period between domestic (TcIDOM) and sylvatic strains. There were no differences in terms of IgG antibodies response across the mice infected with the five strains. Regarding the histopathology, our results indicate that domestic strains present higher parasitemias and low levels of histopathological damage. In contrast, sylvatic strains showed lower parasitemias and high levels of histopathological damage. These results highlight the sympatric and behavioral differences of domestic and sylvatic TcI strains; the clinical and epidemiological implications are herein discussed. PMID:25461848

  8. Mapping the functional properties of soft biological tissues under shear loading

    NASA Astrophysics Data System (ADS)

    Buckley, Mark Raymond

    The structure and composition of articular cartilage and other load-bearing biological tissues are highly complex and heterogeneous. As a result, their functional mechanical properties exhibit clear spatial variations. Unlocking the structure-function relationship in these materials is critical for devising strategies to restore tissue impaired by injury or disease and can provide a template for successful implant design. Here, we describe a tissue deformation imaging stage (TDIS) allowing for simultaneous force measurement and visualization of microscale deformation in soft biological tissues under controlled shear strain. In combination with a fast confocal microscope, the TDIS is used to test the microscale response of articular cartilage to shear loading. To obtain the location-specific shear modulus of this tissue, we employ a high-resolution technique that involves tracking the deformation of a line photobleached into a fluorescently stained sample loaded in the TDIS. We find that the quasi-static and dynamic shear moduli are lowest roughly 100 mum below the articular surface. Here, articular cartilage is highly nonlinear, stiffening under increased shear strain and becoming more compliant under increased compressive strain. Using a simple thought model, we relate these results to structural features of the collagen network in articular cartilage. Furthermore, we demonstrate that the region of maximum compliance is also the primary site of shear energy dissipation in articular cartilage. Our findings suggest that damage to or surgical removal of the surface of this tissue will increase the joint's susceptibility to shear-induced damage. Finally, similar experiments are performed on intervertebral disc and growth plate, demonstrating the versatility of our in-situ strain mapping techniques.

  9. Path-Integration Computation of the Transport Properties of Polymers Nanoparticles and Complex Biological Structures

    NASA Astrophysics Data System (ADS)

    Douglas, Jack

    2014-03-01

    finite cross-section, DNA, nanoparticles with grafted chain layers and knotted polymers. The path-integration method, which grew up from research in Karl Freed's group, is evidently a powerful tool for computing basic transport properties of complex-shaped objects and should find increasing application in polymer science, nanotechnological applications and biology.

  10. LASER METHODS IN BIOLOGY: Optical anisotropy of fibrous biological tissues: analysis of the influence of structural properties

    NASA Astrophysics Data System (ADS)

    Zimnyakov, D. A.; Sinichkin, Yu P.; Ushakova, O. V.

    2007-08-01

    The results of theoretical analysis of the optical anisotropy of multiply scattering fibrillar biological tissues based on the model of an effective anisotropic medium are compared with the experimental in vivo birefringence data for the rat derma obtained earlier in spectral polarisation measurements of rat skin samples in the visible region. The disordered system of parallel dielectric cylinders embedded into an isotropic dielectric medium was considered as a model medium. Simulations were performed taking into account the influence of a partial mutual disordering of the bundles of collagen and elastin fibres in derma on birefringence in samples. The theoretical optical anisotropy averaged over the spectral interval 550-650 nm for the model medium with parameters corresponding to the structural parameters of derma is in good agreement with the results of spectral polarisation measurements of skin samples in the corresponding wavelength range.

  11. Some biologically active oxovanadium(IV) complexes of triazole derived Schiff bases: their synthesis, characterization and biological properties.

    PubMed

    Chohan, Zahid H; Sumrra, Sajjad H

    2010-10-01

    A series of biologically active oxovanadium(IV) complexes of triazole derived Schiff bases L(1)-L(5) have been synthesized and characterized by their physical, analytical, and spectral data. The synthesized ligands potentially act as bidentate, in which the oxygen of furfural and nitrogen of azomethine coordinate with the oxovanadium atom to give a stoichiometry of vanadyl complexes 1:2 (M:L) in a square-pyramidal geometry. In vitro antibacterial and antifungal activities on different species of pathogenic bacteria (E. coli, S. flexneri, P. aeruginosa, S. typhi, S. aureus, and B. subtilis) and fungi (T. longifusus, C. albicans, A. flavus, M. canis, F. solani, and C. glabrata) have been studied. All compounds showed moderate to significant antibacterial activity against one or more bacterial strains and good antifungal activity against most of the fungal strains. The brine shrimp bioassay was also carried out to check the cytotoxicity of coordinated and uncoordinated synthesized compounds. PMID:20429776

  12. Potential of Magnetic Nanofiber Scaffolds with Mechanical and Biological Properties Applicable for Bone Regeneration

    PubMed Central

    Singh, Rajendra K.; Patel, Kapil D.; Lee, Jae Ho; Lee, Eun-Jung; Kim, Joong-Hyun; Kim, Tae-Hyun; Kim, Hae-Won

    2014-01-01

    Magnetic nanofibrous scaffolds of poly(caprolactone) (PCL) incorporating magnetic nanoparticles (MNP) were produced, and their effects on physico-chemical, mechanical and biological properties were extensively addressed to find efficacy for bone regeneration purpose. MNPs 12 nm in diameter were citrated and evenly distributed in PCL solutions up to 20% and then were electrospun into nonwoven nanofibrous webs. Incorporation of MNPs greatly improved the hydrophilicity of the nanofibers. Tensile mechanical properties of the nanofibers (tensile strength, yield strength, elastic modulus and elongation) were significantly enhanced with the addition of MNPs up to 15%. In particular, the tensile strength increase was as high as ∼25 MPa at 15% MNPs vs. ∼10 MPa in pure PCL. PCL-MNP nanofibers exhibited magnetic behaviors, with a high saturation point and hysteresis loop area, which increased gradually with MNP content. The incorporation of MNPs substantially increased the degradation of the nanofibers, with a weight loss of ∼20% in pure PCL, ∼45% in 10% MNPs and ∼60% in 20% MNPs. Apatite forming ability of the nanofibers tested in vitro in simulated body fluid confirmed the substantial improvement gained by the addition of MNPs. Osteoblastic cells favored the MNPs-incorporated nanofibers with significantly improved initial cell adhesion and subsequent penetration through the nanofibers, compared to pure PCL. Alkaline phosphatase activity and expression of genes associated with bone (collagen I, osteopontin and bone sialoprotein) were significantly up-regulated in cells cultured on PCL-MNP nanofibers than those on pure PCL. PCL-MNP nanofibers subcutaneously implanted in rats exhibited minimal adverse tissue reactions, while inducing substantial neoblood vessel formation, which however, greatly limited in pure PCL. In vivo study in radial segmental defects also signified the bone regeneration ability of the PCL-MNP nanofibrous scaffolds. The magnetic, bone

  13. CARBON LOSS AND OPTICAL PROPERTY CHANGES DURING LONG-TERM PHOTOCHEMICAL AND BIOLOGICAL DEGRADATION OF ESTUARINE DISSOLVED ORGANIC MATTER

    EPA Science Inventory

    Terrestrially derived dissolved organic matter (DOM) impacts the optical properties of coastal seawater and affects carbon cycling on a global scale. We studied sequential long-term photochemical and biological degradation of estuarine dissolved organic matter from the
    Satilla...

  14. Optimization of the Hyperspectral Imaging-based Spatially-resolved System for Measuring the Optical Properties of Biological Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports on the optimization and assessment of a hyperspectral imaging-based spatially-resolved system for determination of the optical properties of biological materials over the wavelengths of 500-1,000 nm. Twelve model samples covering a wide range of absorption and reduced scattering c...

  15. Long term effects of annual additions of animal manure on soil chemical, physical, and biological properties in the Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the effects of long-term annual beef manure amendments and wheat and rye cover crops on selected chemical, physical and biological properties of a typical Midwest U.S. soil under corn silage production. The treatments included: manure application/cover cr...

  16. Structure and biological properties of solubilized envelope proteins of Bordetella pertussis.

    PubMed Central

    Robinson, A; Hawkins, D C

    1983-01-01

    The structure and biological properties of solubilized envelope proteins of Bordetella pertussis have been examined. Several envelope proteins were found to be specific for phase I strains of B. pertussis and could be isolated by selective detergent extraction. These proteins had molecular weights of 90,000, 86,000, 81,000, 33,000, 31,000, and 30,000 and were reduced or absent in envelope preparations from Bordetella bronchiseptica, Bordetella parapertussis, or phase IV strains of B. pertussis. When the envelope preparations from phase I B. pertussis were assayed in the mouse intracerebral protection test they were found to be highly protective, and there was a strong correlation between the protective potency and the lymphocytosis-promoting factor (LPF) content of different preparations. Treatment with glutaraldehyde reduced the LPF activity, toxicity, and protective potency of the envelope extracts. Similarly affinity chromatography of envelope proteins on columns of haptoglobin coupled to Sepharose 4B reduced both the LPF content and the protective potency. The addition of a small amount of purified LPF to the haptoglobin-treated proteins restored the protective potency. The LPF by itself was nonprotective, indicating a potentiating role of LPF in the mouse intracerebral challenge test. Images PMID:6299946

  17. Design, synthesis and biological activity of a novel Rutin analogue with improved lipid soluble properties.

    PubMed

    Baldisserotto, Anna; Vertuani, Silvia; Bino, Alessia; De Lucia, Daniela; Lampronti, Ilaria; Milani, Roberta; Gambari, Roberto; Manfredini, Stefano

    2015-01-01

    Recent interest in flavonoids has increased greatly due to their biological and pharmacological activities. Flavonoids, consist of a large group of low molecular weight polyphenolic substances, naturally occurring in fruits, vegetables, tea, and wine, and are an integral part of the human diet. Rutin is a common dietary flavonoid that is widely consumed worldwide from plant-derived beverages and foods as traditional and folk medicine remedy as well. Rutin exhibit important pharmacological activities, including anti-oxidation, anti-inflammation, anti-diabetic, anti-adipogenic, neuroprotective and hormone therapy. Here, we present the synthesis, antimicrobial, antiproliferative and pro-apoptotic effect on human leukemic K562 cells of compound R2, a new semi-synthetic derivative of Rutin as compared to Rutin itself. The new derivative was also included in finished topical formulations to evaluate a potential application to the dermatology field in view of the antioxidant/antimicrobial/antiinflammatory properties. Stability studies were performed by HPLC; PCL assay and ORAC tests were used to determine the antioxidant activity. R2 presented an antioxidant activity very close to that of the parent Rutin while bearing much better lipophilic character. Regarding antiproliferative effects on the human K562 cell line, R2 was found to be more effective than parent Rutin. Preliminary experiments demonstrated that R2 inhibits NF-kB activity and promotes cellular apoptosis. PMID:25496805

  18. Effect of heparin on the biological properties and molecular signature of human mesenchymal stem cells.

    PubMed

    Ling, Ling; Camilleri, Emily T; Helledie, Torben; Samsonraj, Rebekah M; Titmarsh, Drew M; Chua, Ren Jie; Dreesen, Oliver; Dombrowski, Christian; Rider, David A; Galindo, Mario; Lee, Ian; Hong, Wanjin; Hui, James H; Nurcombe, Victor; van Wijnen, Andre J; Cool, Simon M

    2016-01-15

    Chronic use of heparin as an anti-coagulant for the treatment of thrombosis or embolism invokes many adverse systemic events including thrombocytopenia, vascular reactions and osteoporosis. Here, we addressed whether adverse effects might also be directed to mesenchymal stem cells that reside in the bone marrow compartment. Harvested human bone marrow-derived mesenchymal stem cells (hMSCs) were exposed to varying doses of heparin and their responses profiled. At low doses (<200 ng/ml), serial passaging with heparin exerted a variable effect on hMSC proliferation and multipotentiality across multiple donors, while at higher doses (≥ 100 μg/ml), heparin supplementation inhibited cell growth and increased both senescence and cell size. Gene expression profiling using cDNA arrays and RNA-seq analysis revealed pleiotropic effects of low-dose heparin on signaling pathways essential to hMSC growth and differentiation (including the TGFβ/BMP superfamily, FGFs, and Wnts). Cells serially passaged in low-dose heparin possess a donor-dependent gene signature that reflects their altered phenotype. Our data indicate that heparin supplementation during the culturing of hMSCs can alter their biological properties, even at low doses. This warrants caution in the application of heparin as a culture supplement for the ex vivo expansion of hMSCs. It also highlights the need for careful evaluation of the bone marrow compartment in patients receiving chronic heparin treatment. PMID:26484394

  19. Synthesis, biophysical properties and biological activity of second generation antisense oligonucleotides containing chiral phosphorothioate linkages

    PubMed Central

    Wan, W. Brad; Migawa, Michael T.; Vasquez, Guillermo; Murray, Heather M.; Nichols, Josh G.; Gaus, Hans; Berdeja, Andres; Lee, Sam; Hart, Christopher E.; Lima, Walt F.; Swayze, Eric E.; Seth, Punit P.

    2014-01-01

    Bicyclic oxazaphospholidine monomers were used to prepare a series of phosphorothioate (PS)-modified gapmer antisense oligonucleotides (ASOs) with control of the chirality of each of the PS linkages within the 10-base gap. The stereoselectivity was determined to be 98% for each coupling. The objective of this work was to study how PS chirality influences biophysical and biological properties of the ASO including binding affinity (Tm), nuclease stability, activity in vitro and in vivo, RNase H activation and cleavage patterns (both human and E. coli) in a gapmer context. Compounds that had nine or more Sp-linkages in the gap were found to be poorly active in vitro, while compounds with uniform Rp-gaps exhibited activity very similar to that of the stereo-random parent ASOs. Conversely, when tested in vivo, the full Rp-gap compound was found to be quickly metabolized resulting in low activity. A total of 31 ASOs were prepared with control of the PS chirally of each linkage within the gap in an attempt to identify favorable Rp/Sp positions. We conclude that a mix of Rp and Sp is required to achieve a balance between good activity and nuclease stability. PMID:25398895

  20. A functionalizable polyester with free hydroxyl groups and tunable physiochemical and biological properties

    PubMed Central

    You, Zhengwei; Cao, Haiping; Gao, Jin; Shin, Paul H.; Day, Billy W.; Wang, Yadong

    2010-01-01

    Polyesters with free functional groups allow facile modifications with biomolecules, which can lead to versatile biomaterials that afford controlled interactions with cells and tissues. Efficient synthesis of functionalizable polyesters is still a challenge that greatly limits the availability and widespread applications of biofunctionalized synthetic polymers. Here we report a simple route to prepare a functionalizable polyester, poly(sebacoyl diglyceride) (PSeD) bearing free hydroxyl groups. The key synthetic step is an epoxide ring-opening polymerization, instead of the traditional polycondensation, that produces poly(glycerol sebacate) (PGS) [1]. PSeD has a more defined structure with mostly linear backbone, more free hydroxyl groups, higher molecular weight, and lower polydispersity than PGS. Crosslinking PSeD with sebacic acid yields a polymer five times tougher and more elastic than cured PGS. PSeD exhibits good cytocompatibility in vitro. Furthermore, functionalization by glycine proceeds with high efficiency. This versatile synthetic platform can offer a large family of biodegradable, functionalized polymers with tunable physiochemical and biological properties useful for a wide range of biomedical applications. PMID:20149441

  1. Biological properties of purified recombinant HCV particles with an epitope-tagged envelope

    SciTech Connect

    Takahashi, Hitoshi; Akazawa, Daisuke; Kato, Takanobu; Date, Tomoko; Shirakura, Masayuki; Nakamura, Noriko; Mochizuki, Hidenori; Tanaka-Kaneko, Keiko; Sata, Tetsutaro; Tanaka, Yasuhito; Mizokami, Masashi; Suzuki, Tetsuro; Wakita, Takaji

    2010-05-14

    To establish a simple system for purification of recombinant infectious hepatitis C virus (HCV) particles, we designed a chimeric J6/JFH-1 virus with a FLAG (FL)-epitope-tagged sequence at the N-terminal region of the E2 hypervariable region-1 (HVR1) gene (J6/JFH-1/1FL). We found that introduction of an adaptive mutation at the potential N-glycosylation site (E2N151K) leads to efficient production of the chimeric virus. This finding suggests the involvement of glycosylation at Asn within the envelope protein(s) in HCV morphogenesis. To further analyze the biological properties of the purified recombinant HCV particles, we developed a strategy for large-scale production and purification of recombinant J6/JFH-1/1FL/E2N151K. Infectious particles were purified from the culture medium of J6/JFH-1/1FL/E2N151K-infected Huh-7 cells using anti-FLAG affinity chromatography in combination with ultrafiltration. Electron microscopy of the purified particles using negative staining showed spherical particle structures with a diameter of 40-60 nm and spike-like projections. Purified HCV particle-immunization induced both an anti-E2 and an anti-FLAG antibody response in immunized mice. This strategy may contribute to future detailed analysis of HCV particle structure and to HCV vaccine development.

  2. Evaluation of microbial loads, physical characteristics, chemical constituents and biological properties of radiation processed Fagonia arabica

    NASA Astrophysics Data System (ADS)

    Khattak, Khanzadi Fatima

    2012-06-01

    Whole plant of Fagonia arabica with 3 different particle sizes (30, 50 and 70 mesh) were exposed to gamma radiation doses of 1-10 kGy from a Cobalt 60 source. A series of tests was performed in order to check the feasibility of irradiation processing of the plant. The applied radiation doses did not affect (P<0.05) pH and antimicrobial activities of the plant. The total weight of the dry extracts in methanol as well as water was found increased with irradiation. The irradiated samples showed significant increase in phenolic content and free radical scavenging activity using DPPH. Shortly after irradiation (on the day of radiation treatment) high amounts of free radicals were detected in the irradiated plant samples and the chemiluminescence measurements were generally found to be dose dependent. Maximum luminescence intensity was observed in case of samples with mesh size of 30 for all the radiation doses applied. After a period of one month the chemiluminescence signals of the irradiated samples approximated those of the controls. The study suggests that gamma irradiation treatment is effective for quality improvement and enhances certain beneficial biological properties of the treated materials.

  3. Near infrared fluorescence quenching properties of copper (II) ions for potential applications in biological imaging

    NASA Astrophysics Data System (ADS)

    Maji, Dolonchampa; Zhou, Mingzhou; Sarder, Pinaki; Achilefu, Samuel

    2014-03-01

    Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M-1 in 25 mM MES buffer, pH 6.5 at room temperature. We synthesized LS835, a compound containing cypate attached covalently to chelated Cu(II) to study fluorescence quenching by chelated Cu(II). The fluorescence quenching mechanism of chelated Cu(II) is predominantly dynamic or collisional quenching. The quenching efficiency of chelated Cu(II) was calculated to be 58% ± 6% in dimethylsulfoxide at room temperature. Future work will involve further characterization of the mechanism of NIR fluorescence quenching by Cu(II) and testing its reversibility for potential applications in designing fluorophore-quencher based molecular probes for biological imaging.

  4. Biological and Immunogenicity Property of IgY Anti S. mutans ComD

    PubMed Central

    Bachtiar, E.W.; Bachtiar, B.M.; Soejoedono, R.D.; Wibawan, I.W.; Afdhal, A.

    2016-01-01

    Objective: This study aims to elucidate the effect of IgY anti ComD on the biological properties of Streptococcus mutans. (S. mutans) ComD is an interspecies quorum-sensing signaling receptor that plays an important role in biofilm formation by S. mutans. Materials and Methodology: Egg yolk IgY was produced by the immunization of chickens with a DNA vaccine containing the ComD DNA coding region. We evaluated the effect of the antibody on biofilm formation by S. mutans isolated from subjects with or without dental caries. We also assessed the immunoreactivity of the antibody against all isolates, and analyzed the protein profile of S. mutans by SDS-PAGE. Results: The ComD antibody was successfully induced in the hens’ eggs. It inhibited biofilm formation by all S. mutans isolates. In addition, the expression of some protein bands was affected after exposure to the antibody. Conclusion: IgY anti-S. mutans ComD reduces biofilm formation by this bacterium and alters the protein profile of S. mutans. PMID:27386013

  5. The Mechanism and Properties of Electron Transfer in the Biological Organism

    NASA Astrophysics Data System (ADS)

    Pang, Xiao-Feng

    2013-08-01

    The mechanism and properties of electron transfer along protein molecules at finite temperature T ≠ 0 in the life systems are studied using nonlinear theory of bio-energy transport and Green function method, in which the electrons are transferred from donors to acceptors in virtue of the supersound soliton excited by the energy released in ATP hydrolysis. The electron transfer is, in essence, a process of oxidation-reduction reaction. In this study we first give the Hamiltonian and wavefunction of the system and find out the soliton solution of the dynamical equation in the protein molecules with finite temperature, and obtain the dynamical coefficient of the electron transfer. The results show that the speed of the electron transfer is related to the velocity of motion of the soliton, distribution of electrons in the donor and acceptor as well as the interaction strength among them. We finally concluded the changed rule of electric current, arising from the electron transfer, with increasing time. These results are useful in molecular and chemical biology.

  6. The impact of antibiotics (benzylpenicillin, and nystatin) on the biological properties of ordinary chernozems

    NASA Astrophysics Data System (ADS)

    Akimenko, Yu. V.; Kazeev, K. Sh.; Kolesnikov, S. I.

    2014-09-01

    In recent years, the input of antibiotics into soils has sharply increased. We studied the impact antibiotics (benzylpenicillin, pharmasin, and nystatin) at different concentrations (100 and 600 mg/kg) on population densities of microorganisms and enzymatic activity of ordinary chernozems in model experiments. The applied doses of antibiotics had definite suppressing effects on population densities of microorganisms (up to 30-70% of the control) and on the soil enzymatic activity (20-70% of the control). Correlation analysis showed close correlation between the concentrations of antibiotics and the population densities of soil microorganisms ( r = -0.68-0.86). Amylolytic bacteria had the highest resistance to the antibiotics, whereas ammonifying bacteria had the lowest resistance. Among the studied enzymes belonging to oxidoreductases and hydrolases, catalase and phosphatase had the highest and the lowest resistance to the antibiotics, respectively. The effect of antibiotics on the biological properties of the chernozem lasted for a long time. The studied parameters were not completely recovered in 120 days.

  7. Porous Tantalum Structures for Bone Implants: Fabrication, Mechanical and In vitro Biological Properties

    PubMed Central

    Balla, Vamsi Krishna; Bodhak, Subhadip; Bose, Susmita; Bandyopadhyay, Amit

    2010-01-01

    Relatively high cost of manufacturing and inability to produce modular all tantalum implants has limited its widespread acceptance, in spite of its excellent in vitro and in vivo biocompatibility. In this article, we report how to process Ta to create net shape porous structures with varying porosity using Laser Engineered Net Shaping (LENS™) for the first time. Porous Ta samples with relative densities between 45 to 73% have been successfully fabricated and characterized for their mechanical properties. In vitro cell materials interactions, using human osteoblast cell line hFOB, have been accessed on these porous Ta structures and compared with porous Ti control samples. The results show that the Young’s modulus of porous Ta can be tailored between 1.5 to 20 GPa by changing the pore volume fraction between 27 and 55%. In vitro biocompatibility in terms of MTT assay and immunochemistry study showed excellent cellular adherence, growth and differentitation with abundant extracellular matrix formation on porous Ta structures compared to porous Ti control. These results indicate that porous Ta structures can promote enhanced/early biological fixation. The enhanced in vitro cell-materials interactions on porous Ta surface are attributed to chemistry and its high wettability and surface energy relative to porous Ti. Our results show that these laser processed porous Ta structures can find numerous applications, particularly among older patients, for metallic implants because of their excellent bioactivity. PMID:20132912

  8. Effects of sterilization methods on the physical, chemical, and biological properties of silk fibroin membranes.

    PubMed

    de Moraes, Mariana Agostini; Weska, Raquel Farias; Beppu, Marisa Masumi

    2014-05-01

    Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physical, chemical, and biological characteristics of dense and porous silk fibroin membranes. Silk fibroin membranes were treated by several procedures: immersion in 70% ethanol solution, ultraviolet radiation, autoclave, ethylene oxide, and gamma radiation, and were analyzed by scanning electron microscopy, Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction, tensile strength and in vitro cytotoxicity to Chinese hamster ovary cells. The results indicated that the sterilization methods did not cause perceivable morphological changes in the membranes and the membranes were not toxic to cells. The sterilization methods that used organic solvent or an increased humidity and/or temperature (70% ethanol, autoclave, and ethylene oxide) increased the silk II content in the membranes: the dense membranes became more brittle, while the porous membranes showed increased strength at break. Membranes that underwent sterilization by UV and gamma radiation presented properties similar to the nonsterilized membranes, mainly for tensile strength and FTIR results. PMID:24259492

  9. Biological and chemical-physical properties of root-end filling materials: A comparative study

    PubMed Central

    Ceci, Matteo; Beltrami, Riccardo; Chiesa, Marco; Colombo, Marco; Poggio, Claudio

    2015-01-01

    Aim: The purpose of the study is to evaluate and compare the biological and chemical-physical properties of four different root-end filling materials. Materials and Methods: Cytotoxicity towards murine odontoblasts cells (MDPC-23) was evaluated using the Transwell insert methodology by Alamar blue test. Streptococcus salivarius, S. sanguis, and S. mutans strains were selected to evaluate the antimicrobial activity by agar disc diffusion test. Solubility was determined after 24 h and 2 months. pH values were measured after 3 and 24 h. To evaluate radiopacity, all materials were scanned on a GE Healthcare Lunar Prodigy. Results: Excellent percentage of vitality were obtained by mineral trioxide aggregate (MTA)-based materials and Biodentine. MTA-Angelus, ProRoot MTA, and Intermediate Restorative Material (IRM) showed the highest values for the inhibition zones when tested for S. mutans, while Biodentine showed the largest inhibition zone when tested for S. sanguis. All the materials fulfilled the requirements of the International Standard 6876, demonstrating low solubility with a weight loss of less than 3%. No significant reduction in pH value was demonstrated after 24 h. ProRoot MTA and MTA-Angelus showed the highest values of radiographic density. Conclusions: The differences showed by the root-end filling materials tested do not cover completely the ideal clinical requests. PMID:25829684

  10. Comparison of Binding Properties and Early Biological Effects of Elicitins in Tobacco Cells1

    PubMed Central

    Bourque, Stéphane; Ponchet, Michel; Binet, Marie-Noëlle; Ricci, Pierre; Pugin, Alain; Lebrun-Garcia, Angela

    1998-01-01

    Elicitins are a family of small proteins secreted by Phytophthora species that have a high degree of homology and elicit defense reactions in tobacco (Nicotiana tabacum). They display acidic or basic characteristics, the acidic elicitins being less efficient in inducing plant necrosis. In this study we compared the binding properties of four elicitins (two basic and two acidic) and early-induced signal transduction events (Ca2+ influx, extracellular medium alkalinization, and active oxygen species production). The affinity for tobacco plasma membrane-binding sites and the number of binding sites were similar for all four elicitins. Furthermore, elicitins compete with one another for binding sites, suggesting that they interact with the same receptor. The four elicitins induced Ca2+ influx, extracellular medium alkalinization, and the production of active oxygen species in tobacco cell suspensions, but the intensity and kinetics of these effects were different from one elicitin to another. As a general observation the concentrations that induce similar levels of biological activities were lower for basic elicitins (with the exception of cinnamomin-induced Ca2+ uptake). The qualitative similarity of early events induced by elicitins indicates a common transduction scheme, whereas fine signal transduction tuning is different in each elicitin. PMID:9847105

  11. Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

    PubMed Central

    Sangpheak, Waratchada; Kicuntod, Jintawee; Schuster, Roswitha; Rungrotmongkol, Thanyada; Wolschann, Peter; Kungwan, Nawee; Viernstein, Helmut

    2015-01-01

    Summary The aim of this work is to improve physical properties and biological activities of the two flavanones hesperetin and naringenin by complexation with β-cyclodextrin (β-CD) and its methylated derivatives (2,6-di-O-methyl-β-cyclodextrin, DM-β-CD and randomly methylated-β-CD, RAMEB). The free energies of inclusion complexes between hesperetin with cyclodextrins (β-CD and DM-β-CD) were theoretically investigated by molecular dynamics simulation. The free energy values obtained suggested a more stable inclusion complex with DM-β-CD. The vdW force is the main guest–host interaction when hesperetin binds with CDs. The phase solubility diagram showed the formation of a soluble complex of AL type, with higher increase in solubility and stability when hesperetin and naringenin were complexed with RAMEB. Solid complexes were prepared by freeze-drying, and the data from differential scanning calorimetry (DSC) confirmed the formation of inclusion complexes. The data obtained by the dissolution method showed that complexation with RAMEB resulted in a better release of both flavanones to aqueous solution. The flavanones-β-CD/DM-β-CD complexes demonstrated a similar or a slight increase in anti-inflammatory activity and cytotoxicity towards three different cancer cell lines. The overall results suggested that solubilities and bioactivities of both flavanones were increased by complexation with methylated β-CDs. PMID:26877798

  12. Chemical and biological properties in the rhizosphere of Lupinus albus alter soil heavy metal fractionation.

    PubMed

    Martínez-Alcalá, I; Walker, D J; Bernal, M P

    2010-05-01

    To understand better the suitability of white lupin (Lupinus albus L.) for phytoremediation of heavy metal-contaminated soils, the effect of its roots on chemical and biological properties of the rhizosphere affecting soil metal fractionation was studied. Plants were cultivated in two similar soils, with high levels of Zn, Cd, Cu and Pb but differing pH values (4.2 and 6.8). In the rhizosphere of both soils, its roots induced increases in water-soluble carbon, which influenced the fractionation of heavy metals and ultimately their uptake by plant roots. In the rhizosphere of the acid soil, the concentrations of 0.1M CaCl(2)-extractable Mn, Zn and Cu were lower than in the bulk soil, possibly due to their increased retention on Fe (III) hydroxides/oxyhydroxides, while in the neutral soil only the Zn concentration was lower. Higher concentrations of heavy metals were found in plants growing on the acid soil, reflecting their greater availability in this soil. The restricted transfer of heavy metals to the shoot confirms the potential role of this species in the initial phytoimmobilisation of heavy metals, particularly in neutral-alkaline soils. PMID:20060590

  13. Isolation, Characterization and Biological Properties of Membrane Vesicles Produced by the Swine Pathogen Streptococcus suis

    PubMed Central

    Haas, Bruno; Grenier, Daniel

    2015-01-01

    Streptococcus suis, more particularly serotype 2, is a major swine pathogen and an emerging zoonotic agent worldwide that mainly causes meningitis, septicemia, endocarditis, and pneumonia. Although several potential virulence factors produced by S. suis have been identified in the last decade, the pathogenesis of S. suis infections is still not fully understood. In the present study, we showed that S. suis produces membrane vesicles (MVs) that range in diameter from 13 to 130 nm and that appear to be coated by capsular material. A proteomic analysis of the MVs revealed that they contain 46 proteins, 9 of which are considered as proven or suspected virulence factors. Biological assays confirmed that S. suis MVs possess active subtilisin-like protease (SspA) and DNase (SsnA). S. suis MVs degraded neutrophil extracellular traps, a property that may contribute to the ability of the bacterium to escape the host defense response. MVs also activated the nuclear factor-kappa B (NF-κB) signaling pathway in both monocytes and macrophages, inducing the secretion of pro-inflammatory cytokines, which may in turn contribute to increase the permeability of the blood brain barrier. The present study brought evidence that S. suis MVs may play a role as a virulence factor in the pathogenesis of S. suis infections, and given their composition be an excellent candidate for vaccine development. PMID:26110524

  14. The organization of biological sequences into constrained and unconstrained parts determines fundamental properties of genotype-phenotype maps.

    PubMed

    Greenbury, S F; Ahnert, S E

    2015-12-01

    Biological information is stored in DNA, RNA and protein sequences, which can be understood as genotypes that are translated into phenotypes. The properties of genotype-phenotype (GP) maps have been studied in great detail for RNA secondary structure. These include a highly biased distribution of genotypes per phenotype, negative correlation of genotypic robustness and evolvability, positive correlation of phenotypic robustness and evolvability, shape-space covering, and a roughly logarithmic scaling of phenotypic robustness with phenotypic frequency. More recently similar properties have been discovered in other GP maps, suggesting that they may be fundamental to biological GP maps, in general, rather than specific to the RNA secondary structure map. Here we propose that the above properties arise from the fundamental organization of biological information into 'constrained' and 'unconstrained' sequences, in the broadest possible sense. As 'constrained' we describe sequences that affect the phenotype more immediately, and are therefore more sensitive to mutations, such as, e.g. protein-coding DNA or the stems in RNA secondary structure. 'Unconstrained' sequences, on the other hand, can mutate more freely without affecting the phenotype, such as, e.g. intronic or intergenic DNA or the loops in RNA secondary structure. To test our hypothesis we consider a highly simplified GP map that has genotypes with 'coding' and 'non-coding' parts. We term this the Fibonacci GP map, as it is equivalent to the Fibonacci code in information theory. Despite its simplicity the Fibonacci GP map exhibits all the above properties of much more complex and biologically realistic GP maps. These properties are therefore likely to be fundamental to many biological GP maps. PMID:26609063

  15. The organization of biological sequences into constrained and unconstrained parts determines fundamental properties of genotype–phenotype maps

    PubMed Central

    Greenbury, S. F.; Ahnert, S. E.

    2015-01-01

    Biological information is stored in DNA, RNA and protein sequences, which can be understood as genotypes that are translated into phenotypes. The properties of genotype–phenotype (GP) maps have been studied in great detail for RNA secondary structure. These include a highly biased distribution of genotypes per phenotype, negative correlation of genotypic robustness and evolvability, positive correlation of phenotypic robustness and evolvability, shape-space covering, and a roughly logarithmic scaling of phenotypic robustness with phenotypic frequency. More recently similar properties have been discovered in other GP maps, suggesting that they may be fundamental to biological GP maps, in general, rather than specific to the RNA secondary structure map. Here we propose that the above properties arise from the fundamental organization of biological information into ‘constrained' and ‘unconstrained' sequences, in the broadest possible sense. As ‘constrained' we describe sequences that affect the phenotype more immediately, and are therefore more sensitive to mutations, such as, e.g. protein-coding DNA or the stems in RNA secondary structure. ‘Unconstrained' sequences, on the other hand, can mutate more freely without affecting the phenotype, such as, e.g. intronic or intergenic DNA or the loops in RNA secondary structure. To test our hypothesis we consider a highly simplified GP map that has genotypes with ‘coding' and ‘non-coding' parts. We term this the Fibonacci GP map, as it is equivalent to the Fibonacci code in information theory. Despite its simplicity the Fibonacci GP map exhibits all the above properties of much more complex and biologically realistic GP maps. These properties are therefore likely to be fundamental to many biological GP maps. PMID:26609063

  16. Study Under AC Stimulation on Excitement Properties of Weighted Small-World Biological Neural Networks with Side-Restrain Mechanism

    NASA Astrophysics Data System (ADS)

    Yuan, Wu-Jie; Luo, Xiao-Shu; Jiang, Pin-Qun

    2007-02-01

    In this paper, we propose a new model of weighted small-world biological neural networks based on biophysical Hodgkin-Huxley neurons with side-restrain mechanism. Then we study excitement properties of the model under alternating current (AC) stimulation. The study shows that the excitement properties in the networks are preferably consistent with the behavior properties of a brain nervous system under different AC stimuli, such as refractory period and the brain neural excitement response induced by different intensities of noise and coupling. The results of the study have reference worthiness for the brain nerve electrophysiology and epistemological science.

  17. Conformational assembly and biological properties of collagen mimetic peptides and their thermally responsive polymer conjugates

    NASA Astrophysics Data System (ADS)

    Krishna, Ohm Divyam

    2011-12-01

    Collagens are one of the most abundant proteins found in body tissues and organs, endowing structural integrity, mechanical strength, and multiple biological functions. Destabilized collagen inside human body leads to various degenerative diseases (ex. osteoarthritis) and ageing. This has continued to motivate the design of synthetic peptides and bio-synthetic polypeptides to closely mimic the native collagens in terms of triple helix structure and stability, potential for higher order assembly, and biological properties. However, the widespread application of de novo collagens has been limited in part by the need for hydroxylated proline in the formation of stable triple helical structures. To address this continued need, a hydroxyproline-free, thermally stable collagen-mimetic peptide (CLP-Cys) was rationally designed via the incorporation of electrostatically stabilized amino acid triplets. CLP-Cys was synthesized via solid phase peptide synthesis. The formation and stability of the triple helical structure were indicated via circular dichroism (CD) experiments and confirmed via differential scanning calorimetry (DSC) results. CLP-Cys also self-assembled into nano-rods and micro-fibrils, as evidenced via a combination of dynamic light scattering and transmission electron microscopy. Given the high thermal stability and its propensity for higher-order assembly, CLP-Cys was further functionalized at both the ends with a thermally responsive polymer, poly(diethylene glycol methyl ether methacrylate), (PDEGMEMA) to synthesize a biohybrid triblock copolymer. The CD results indicated that the triple helical form is retained, the thermal unfolding is sustained and helix to coil transition is reversible in the triblock hybrid context. The LCST of PDEGMEMA homopolymer (26 °C) is increased (to 35 °C) upon conjugation to the hydrophilic collagen peptide domain. Further, a combination of static light scattering, Cryo-SEM, TEM and confocal microscopy elucidated that the

  18. trkC encodes multiple neurotrophin-3 receptors with distinct biological properties and substrate specificities.

    PubMed Central

    Lamballe, F; Tapley, P; Barbacid, M

    1993-01-01

    The trkC gene product gp145trkC is a high affinity signaling receptor for neurotrophin-3 (NT-3), a member of the NGF family of neurotrophic factors. We now report that trkC encodes at least two additional tyrosine protein kinase receptors. These receptors, designated TrkC K2 and TrkC K3, have the same amino acid sequences as gp145trkC (now designated TrkC K1) except for the presence of 14 and 25 additional amino acid residues between kinase subdomains VII and VIII, just downstream from the TDYYR motif which encompasses the putative autophosphorylation site of the Trk receptor family. Upon interaction with their cognate ligand, NT-3, all three TrkC receptor isoforms become rapidly phosphorylated on tyrosine residues and induce DNA synthesis in quiescent cells. However, only TrkC K1 has mitogenic activity in NIH3T3 cells and induces neuronal differentiation of PC12 cells. The different biological properties of these TrkC receptor isoforms probably result from their engagement with different signaling pathways. Whereas TrkC K1 phosphorylates phospholipase C gamma 1 and phosphatidylinositol-3 kinase, TrkC K2 and TrkC K3 do not. TrkC K2 and transcripts encoding TrkC K3 have been identified in various structures of the adult murine brain. These observations suggest that the trophic activities of NT-3 in the mammalian nervous system might be mediated by different TrkC receptor isoforms. Images PMID:8344249

  19. Yellow Fever/Japanese Encephalitis Chimeric Viruses: Construction and Biological Properties

    PubMed Central

    Chambers, Thomas J.; Nestorowicz, Ann; Mason, Peter W.; Rice, Charles M.

    1999-01-01

    A system has been developed for generating chimeric yellow fever/Japanese encephalitis (YF/JE) viruses from cDNA templates encoding the structural proteins prM and E of JE virus within the backbone of a molecular clone of the YF17D strain. Chimeric viruses incorporating the proteins of two JE strains, SA14-14-2 (human vaccine strain) and JE Nakayama (JE-N [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. The JE envelope protein (E) retained antigenic and biological properties when expressed with its prM protein together with the YF capsid; however, viable chimeric viruses incorporating the entire JE structural region (C-prM-E) could not be obtained. YF/JE(prM-E) chimeric viruses grew efficiently in cells of vertebrate or mosquito origin compared to the parental viruses. The YF/JE SA14-14-2 virus was unable to kill young adult mice by intracerebral challenge, even at doses of 106 PFU. In contrast, the YF/JE-N virus was neurovirulent, but the phenotype resembled parental YF virus rather than JE-N. Ten predicted amino acid differences distinguish the JE E proteins of the two chimeric viruses, therefore implicating one or more residues as virus-specific determinants of mouse neurovirulence in this chimeric system. This study indicates the feasibility of expressing protective antigens of JE virus in the context of a live, attenuated flavivirus vaccine strain (YF17D) and also establishes a genetic system for investigating the molecular basis for neurovirulence determinants encoded within the JE E protein. PMID:10074160

  20. Effects of selenium on biological and physiological properties of the duckweed Landoltia punctata.

    PubMed

    Zhong, Y; Cheng, J J

    2016-09-01

    Duckweed can be used for bioremediation of selenium (Se) polluted water because of its capability of absorbing minerals from growing media. However, the presence of Se in the media may affect the growth of the duckweed. Landoltia punctata 7449 has been studied for its changes in chemical and biological properties with the presence of Se in the media. The duckweed was cultivated over a 12-day period at different initial concentrations of selenite (Na2 SeO3 ) from 0 to 80 μmol·l(-1) . The growth rate, the organic and total Se contents, the activity of antioxidant enzymes, the photosynthetic pigment contents, the chlorophyll a fluorescence OJIP transient, and the ultrastructure of the duckweed were monitored during the experiment. The results have shown that Se at low concentrations of ≤20 μmol·l(-1) promoted the growth of the L. punctata and inhibited lipid peroxidation. Substantial increases in duckweed growth rate and organic Se content in the duckweed were observed at low Se concentrations. The anti-oxidative effect occurred likely with the increases in guaiacol peroxidase, catalase and superoxide dismutase activities as well as the amount of photosynthetic pigments. However, negative impact to the duckweed was observed when the L. punctata was exposed to high Se concentrations (≥40 μmol·l(-1) ), in which the duckweed growth was inhibited by the selenium. The results indicate that L. punctata 7449 can be used for bioremediation of selenium (Se) polluted water when the Se concentration is ≤20 μmol·l(-1) . PMID:27284791

  1. Pegylation of biological molecules and potential benefits: pharmacological properties of certolizumab pegol.

    PubMed

    Pasut, Gianfranco

    2014-04-01

    PEGylation of biological proteins, defined as the covalent conjugation of proteins with polyethylene glycol (PEG), leads to a number of biopharmaceutical improvements, including increased half-life, increased solubility and reduced aggregation, and reduced immunogenicity. Since their introduction in 1990, PEGylated proteins have significantly improved the management of various chronic diseases, including rheumatoid arthritis (RA) and Crohn's disease. Certolizumab pegol is the only PEGylated anti-tumour necrosis factor (TNF)-α agent. It is a PEGylated, humanised, antigen-binding fragment of an anti-TNF monoclonal antibody. Unlike other anti-TNF agents, it has no crystallisable fragment (Fc) domain. Because of its novel structure, certolizumab pegol may have a different mechanism of action to the other anti-TNF agents, and also has different pharmacodynamic properties, which could possibly translate to a different safety profile. Pharmacodynamic studies have shown that certolizumab pegol binds to TNF with a higher affinity than adalimumab and infliximab. Certolizumab pegol is also more potent at neutralising soluble TNF-mediated signalling than adalimumab and infliximab, and has similar or lesser potency to etanercept. Certolizumab pegol does not cause detrimental in vitro effects such as degranulation, loss of cell integrity, apoptosis, complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. Certolizumab pegol may also penetrate more effectively into inflamed arthritic tissue than other anti-TNF agents, and is not actively transported across the placenta during pregnancy. Pharmacokinetic studies in healthy volunteers demonstrated that single intravenous and subcutaneous doses of certolizumab pegol had predictable pharmacokinetics. The pharmacokinetics of certolizumab pegol in patients with RA and Crohn's disease were consistent with pharmacokinetics in healthy volunteers. PMID:24687235

  2. Photophysical properties of biologically compatible CdSe quantum dot structures.

    PubMed

    Kloepfer, Jeremiah A; Bradforth, Stephen E; Nadeau, Jay L

    2005-05-26

    The photophysical properties of CdSe and ZnS(CdSe) semiconductor quantum dots in nonpolar and aqueous solutions were examined with steady-state (absorption and emission) and time-resolved (time-correlated single-photon-counting) spectroscopy. The CdSe structures were prepared from a single CdSe synthesis, a portion of which were ZnS-capped, thus any differences observed in the spectral behavior between the two preparations were due to changes in the molecular shell. Quantum dots in nonpolar solvents were surrounded with a trioctylphosphine oxide (TOPO) coating from the initial synthesis solution. ZnS-capped CdSe were initially brighter than bare uncapped CdSe and had overall faster emission decays. The dynamics did not vary when the solvent was changed from hexane to dichloromethane; however, replacement of the TOPO cap by pyridine affected CdSe but not ZnS(CdSe). CdSe was then solubilized in water with mercapto-acetic acid or dihydrolipoic acid, whereas ZnS(CdSe) could be solubilized only with dihydrolipoic acid. Both solubilization agents quenched the nanocrystal emission, though with CdSe the quenching was nearly complete. Additional quenching of the remaining emission was observed when the redox-active molecule adenine was conjugated to the water-soluble CdSe but was not seen with ZnS(CdSe). The emission of aqueous CdSe could be enhanced under prolonged exposure to room light and resulted in a substantial increase of the emission lifetimes; however, the enhancement occurred concurrently with precipitation of the nanocrystals, which was possibly caused by photocatalytic destruction of the mercaptoacetic acid coating. These results are the first presented on aqueous CdSe quantum dot structures and are presented in the context of designing better, more stable biological probes. PMID:16852208

  3. A review on chemical and biological properties of Cayratia trifolia Linn. (Vitaceae).

    PubMed

    Kumar, Dinesh; Kumar, Sunil; Gupta, Jyoti; Arya, Renu; Gupta, Ankit

    2011-07-01

    Cayratia trifolia Linn. Domin Syn. Vitis trifolia (Family: Vitaceae) is commonly known as Fox grape in English; Amlabel, Ramchana in Hindi and Amlavetash in Sanskrit. It is native to India, Asia and Australia. It is a perennial climber having trifoliated leaves with 2-3 cm long petioles and ovate to oblong-ovate leaflets. Flowers are small greenish white and brown in color. Fruits are fleshy, juicy, dark purple or black, nearly spherical, about 1 cm in diameter. It is found throughout the hills in India. This perennial climber is also found in the hotter part of India from Jammu and Rajasthan to Assam extending into the peninusular India upto 600 m height. Whole plant of Cayratia trifolia has been reported to contain yellow waxy oil, steroids/terpenoids, flavonoids, tannins upon preliminary phytochemical screening. Leaves contain stilbenes (piceid, reveratrol, viniferin, ampelopsin). Stem, leaves, roots are reported to possess hydrocyanic acid, delphinidin and several flavonoids such as cyanidin is reported in the leaves. This plant also contains kaempferol, myricetin, quercetin, triterpenes and epifriedelanol. Infusion of seeds along with extract of tubers is traditionally given orally to diabetic patients to check sugar level of blood. Paste of tuberous is applied on the affected part in the treatment of snake bite. Whole plant is used as diuretic, in tumors, neuralgia and splenopathy. Its climbers wrapped around the neck of frantic bullock and poultice of leaves are used to yoke sores of bullock. The bark extract shows the antiviral, antibacterial, antiprotozoal, hypoglycemic, anticancer and diuretic activity. This article focuses on the upgraded review on chemical and biological properties of Cayratia trifolia Linn. and triggers further investigation on this plant. PMID:22279376

  4. The influence comparing of activated biochar and conventional biochar on the soil biological properties

    NASA Astrophysics Data System (ADS)

    Dvořáčková, Helena; Mykajlo, Irina; Záhora, Jaroslav

    2016-04-01

    In our experiment we have used biochar. This material is the product of the pyrolysis that has shown a positive effect on numerous physical and chemical soil properties. However, its influence on the biological component of the soil is very variable. A number of toxic substances that inhibit the soil productivity may be produced during pyrolysis process. The experiment dealt with the hypothesis concerning biochar toxicity reduction by simulating natural processes in the soil. Biochar has been exposed to aeration in the aquatic environment, enriched with nutrients and a source of native soil microflora. It has been created 6 variants in total, each with four replications. The soils samples have been placed in a phytotron for 90 days. Variants consisted of the soil with fertilizers adding (compost, biochar, activated biochar) and have been prepared as well as variants containing compost and biochar and activated biochar optionally. The highest aboveground biomass production has been estimated in variants containing compost, while the lowest production - in the variants containing conventional biochar. During production comparing of the variants with the conventional biochar, activated biochar and control samples it has been evident that activated biochar promotes plant growth, and in contradiction conventional biochar inhibits it. We will approach to the same conclusions when comparing variants with a combination of conventional biochar + compost and activated biochar + compost. Mineral nitrogen leaching has been another investigated parameter. The highest leaching has occurred in the control variant, while the lowest - in the variant with activated biochar (the leaching of nitrate nitrogen has been negligeable). Our results suggest that activated biochar has the potential; however, it is necessary to carry out similar experiments in the field conditions.

  5. Biological Motion Preference in Humans at Birth: Role of Dynamic and Configural Properties

    ERIC Educational Resources Information Center

    Bardi, Lara; Regolin, Lucia; Simion, Francesca

    2011-01-01

    The present study addresses the hypothesis that detection of biological motion is an intrinsic capacity of the visual system guided by a non-species-specific predisposition for the pattern of vertebrate movement and investigates the role of global vs. local information in biological motion detection. Two-day-old babies exposed to a biological…

  6. Grammatical Gender and Inferences about Biological Properties in German-Speaking Children

    ERIC Educational Resources Information Center

    Saalbach, Henrik; Imai, Mutsumi; Schalk, Lennart

    2012-01-01

    In German, nouns are assigned to one of the three gender classes. For most animal names, however, the assignment is independent of the referent's biological sex. We examined whether German-speaking children understand this independence of grammar from semantics or whether they assume that grammatical gender is mapped onto biological sex when…

  7. Physicochemical and biological properties of oxovanadium(IV), cobalt(II) and nickel(II) complexes with oxydiacetate anions.

    PubMed

    Wyrzykowski, Dariusz; Kloska, Anna; Pranczk, Joanna; Szczepańska, Aneta; Tesmar, Aleksandra; Jacewicz, Dagmara; Pilarski, Bogusław; Chmurzyński, Lech

    2015-03-01

    The potentiometric and conductometric titration methods have been used to characterize the stability of series of VO(IV)-, Co(II)- and Ni(II)-oxydiacetato complexes in DMSO-water solutions containing 0-50 % (v/v) DMSO. The influence of DMSO as a co-solvent on the stability of the complexes as well as the oxydiacetic acid was evaluated. Furthermore, the reactivity of the complexes towards superoxide free radicals was assessed by employing the nitro blue tetrazolium (NBT) assay. The biological properties of the complexes were investigated in relation to their cytoprotective activity against the oxidative damage generated exogenously by using hydrogen peroxide in the Human Dermal Fibroblasts adult (HDFa) cell line as well as to their antimicrobial activity against the bacteria (Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis). The relationship between physicochemical and biological properties of the complexes was discussed. PMID:25488702

  8. Nanomechanical control of properties of biological membranes achieved by rodlike magnetic nanoparticles in a superlow-frequency magnetic field

    NASA Astrophysics Data System (ADS)

    Golovin, Yu. I.; Klyachko, N. L.; Gribanovskii, S. L.; Golovin, D. Yu.; Samodurov, A. A.; Majouga, A. G.; Sokolsky-Papkov, M.; Kabanov, A. V.

    2015-05-01

    It is proposed to use single-domain rodlike magnetic nanoparticles (MNPs) as mediators for nanomechanical control of properties of biological membranes and cells on the molecular or cellular level by exposing them to a homogeneous nonheating low-frequency magnetic field (AC MF). The trigger effect is achieved due to rotatory-oscillatory motion of MNPs in the AC MF, which causes the needed deformations in macromolecules of the membrane interacting with these MNPs.

  9. Biological properties and molecular targets of umbelliprenin--a mini-review.

    PubMed

    Shakeri, Abolfazl; Iranshahy, Milad; Iranshahi, Mehrdad

    2014-01-01

    7-Prenyloxycoumarins are a group of secondary metabolites found mainly in plants belonging to the families Rutaceae and Apiaceae. Auraptene, umbelliprenin (UM), and 7-isopentenyloxycoumarin are some examples of prenylated coumarins. UM occurs in various edible plant species including celery, coriander, angelica, lemon, and particularly, Ferula species. Although UM was isolated more than 50 years ago, its biological activities have been studied since the last two decades. Besides anticancer activities, biological activities including anti-inflammatory, antioxidant, and antileishmanial activities have been reported from this natural compound. The present mini-review deals with the biological activities and mechanism of actions reported for UM. PMID:24852499

  10. [Effects of composting with earthworm on the chemical and biological properties of agricultural organic wastes: a principal component analysis].

    PubMed

    Liu, Ting; Ren, Zong-Ling; Zhang, Chi; Chen, Xu-Fei; Zhou, Bo; Dai, Jun

    2012-03-01

    Taking mixed agricultural organic wastes cattle manure and rice straw (C:N = 28.7:1) as the substrate of earthworm Eisenia foetida, an experiment was conducted to study the effects of earthworm on the changes of the chemical and biological properties of wastes during vermi-composting. After 30 days of vermi-composting, the substrate' s pH and C/N decreased while the total P content increased significantly, and the total N, available N, dissolved organic carbon, available P content, microbial biomass-C, respiration rate, and microbial quotient increased by 8.5% , 2.6%, 1.8%, 6.3%, 21.2%, 4.4%, and 30.0% whereas the organic matter content and metabolic quotient decreased by 5.0% and 21.9%, respectively, as compared with natural composting. Vermi-composting made the substrate have higher invertase, acid phosphatase, and alkaline phosphatase activities but lower catalase and urease activities. Principal component analysis and discriminant analysis confirmed the significant differences in the substrate' s chemical and biological properties between vermi-composting and natural composting. This study indicated that vermi-composting was superior to natural composting, which could obviously improve the chemical and biological properties of composted organic materials, being a high efficient technology for the management of agricultural organic wastes. PMID:22720625

  11. Using Petri Net Tools to Study Properties and Dynamics of Biological Systems

    PubMed Central

    Peleg, Mor; Rubin, Daniel; Altman, Russ B.

    2005-01-01

    Petri Nets (PNs) and their extensions are promising methods for modeling and simulating biological systems. We surveyed PN formalisms and tools and compared them based on their mathematical capabilities as well as by their appropriateness to represent typical biological processes. We measured the ability of these tools to model specific features of biological systems and answer a set of biological questions that we defined. We found that different tools are required to provide all capabilities that we assessed. We created software to translate a generic PN model into most of the formalisms and tools discussed. We have also made available three models and suggest that a library of such models would catalyze progress in qualitative modeling via PNs. Development and wide adoption of common formats would enable researchers to share models and use different tools to analyze them without the need to convert to proprietary formats. PMID:15561791

  12. Characterizing and optimizing human anticancer drug targets based on topological properties in the context of biological pathways.

    PubMed

    Zhang, Jian; Wang, Yan; Shang, Desi; Yu, Fulong; Liu, Wei; Zhang, Yan; Feng, Chenchen; Wang, Qiuyu; Xu, Yanjun; Liu, Yuejuan; Bai, Xuefeng; Li, Xuecang; Li, Chunquan

    2015-04-01

    One of the challenging problems in drug discovery is to identify the novel targets for drugs. Most of the traditional methods for drug targets optimization focused on identifying the particular families of "druggable targets", but ignored their topological properties based on the biological pathways. In this study, we characterized the topological properties of human anticancer drug targets (ADTs) in the context of biological pathways. We found that the ADTs tended to present the following seven topological properties: influence the number of the pathways related to cancer, be localized at the start or end of the pathways, interact with cancer related genes, exhibit higher connectivity, vulnerability, betweenness, and closeness than other genes. We first ranked ADTs based on their topological property values respectively, then fused them into one global-rank using the joint cumulative distribution of an N-dimensional order statistic to optimize human ADTs. We applied the optimization method to 13 anticancer drugs, respectively. Results demonstrated that over 70% of known ADTs were ranked in the top 20%. Furthermore, the performance for mercaptopurine was significant: 6 known targets (ADSL, GMPR2, GMPR, HPRT1, AMPD3, AMPD2) were ranked in the top 15 and other four out of the top 15 (MAT2A, CDKN1A, AREG, JUN) have the potentialities to become new targets for cancer therapy. PMID:25724580

  13. Near infrared spectra are more sensitive to land use changes than physical, chemical and biological soil properties

    NASA Astrophysics Data System (ADS)

    Guerrero, C.; Zornoza, R.; Mataix-Solera, J.; Mataix-Beneyto, J.; Scow, K.

    2009-04-01

    We studied the sensibility of the near infrared spectra (NIR) of soils to the changes caused by land use, and we compared with the sensibility of different sets of physical, chemical and biological soil properties. For this purpose, we selected three land uses, constituted by forest, almond trees orchards, and orchards abandoned between 10 and 15 years previously to sampling. Sampling was carried out in four different locations from the province of Alicante (SE Spain). We used discriminant analysis (DA) using different sets of soil properties. The different sets tested in this study using DA were: (1) physical and chemical properties (organic carbon, total nitrogen, available phosphorus, pH, electrical conductivity, cation exchange capacity, aggregate stability, water holding capacity, and available Ca, Mg, K and Na), (2) biochemical properties (microbial biomass carbon, basal respiration and urease, phosphatase and β-glucosidase activities), (3) phospholipids fatty acids (PLFAs), (4) physical, chemical and biochemical properties (all properties of the previous sets), and (5) the NIR spectra of soils (scores of the principal components). In general, all sets of properties were sensible to land use. This was observed in the DAs by the separation (more or less clear) of samples in groups defined by land use (irrespective of site). The worst results were obtained using soil physical and chemical properties. The combination of physical, chemical and biological properties enhanced the separation of samples in groups, indicating higher sensibility. It is accepted than combination of properties of different nature is more effective to evaluate the soil quality. The microbial community structure (PLFAs) was highly sensible to the land use, grouping correctly the 100% of the samples according with the land use. The NIR spectra were also sensitive to land use. The scores of the first 5 components, which explained 99.97% of the variance, grouped correctly the 85% of the soil

  14. Mobility as an emergent property of biological organization: Insights from experimental evolution.

    PubMed

    Wallace, Ian J; Garland, Theodore

    2016-05-01

    Anthropologists accept that mobility is a critical dimension of human culture, one that links economy, technology, and social relations. Less often acknowledged is that mobility depends on complex and dynamic interactions between multiple levels of our biological organization, including anatomy, physiology, neurobiology, and genetics. Here, we describe a novel experimental approach to examining the biological foundations of mobility, using mice from a long-term artificial selection experiment for high levels of voluntary exercise on wheels. In this experiment, mice from selectively bred lines have evolved to run roughly three times as far per day as those from nonselected control lines. We consider three insights gleaned from this experiment as foundational principles for the study of mobility from the perspective of biological evolution. First, an evolutionary change in mobility will necessarily be associated with alterations in biological traits both directly and indirectly connected to mobility. Second, changing mobility will result in trade-offs and constraints among some of the affected traits. Third, multiple solutions exist to altering mobility, so that various combinations of adjustments to traits linked with mobility can achieve the same overall behavioral outcome. We suggest that anthropological knowledge of variation in human mobility might be improved by greater research attention to its biological dimensions. PMID:27312181

  15. The effect of model soil contamination with Cr, Cu, Ni, and Pb on the biological properties of soils in the dry steppe and semidesert regions of southern Russia

    NASA Astrophysics Data System (ADS)

    Kolesnikov, S. I.; Spivakova, N. A.; Kazeev, K. Sh.

    2011-09-01

    Model soil contamination with Cr, Cu, Ni, and Pb in the dry steppes and semideserts of southern Russia has worsened the biological soil properties. With respect to the degree of deterioration of the biological properties, the soils can be arranged in the following sequence: dark chestnut soils > chestnut soils > light chestnut soils > brown semidesert soils > sandy brown semidesert soils. The sequence of metal oxides according to the adverse effect on the biological soil properties is as follows: CrO3 > CuO ≥ PbO ≥ NiO.

  16. Interaction of silver nanoparticles with biological objects: antimicrobial properties and toxicity for the other living organisms

    NASA Astrophysics Data System (ADS)

    Egorova, E. M.

    2011-04-01

    This paper presents several examples of the biological effects of small-sized silver nanoparticles (10.5±3.5nm) observed in experiments on bacteria, slim mold, unicellular alga and plant seeds. The nanoparticles were prepared by the biochemical synthesis, based on the reduction of metal ions in reverse vicelles by biological reductants - natural plant pigments (flavonoids). It is found that, except for the plant seeds, silver nanoparticles (SNP) act as a strong toxic agent, both in water solution and as part of liquid-phase material. It is shown also that the biological action of silver nanoparticles can not be reduced to the toxic action of silver ions in equivalent concentrations or to that of the surfactant (the SNP stabilizer) present in the SNP water solution. Possible SNP applications are suggested.

  17. Biological and Chemical Properties of the Epidioxide Isomer of Abscisic Acid and its Rearrangement Products

    PubMed Central

    Sondheimer, Ernest; Michniewicz, Barbara M.; Powell, Loyd E.

    1969-01-01

    The growth inhibitory activity of the epidioxide (II), a precursor in the synthesis of abscisic acid (ABA), has been confirmed with additional assay systems. Under physiological conditions the epidioxide is rearranged to give ABA and an isomer of ABA which has probably the structure V. This major product has very low, if any, biological activity. The biological activity of the epidioxide is explained by its partial conversion (about 20%) to ABA. The reaction rate was enhanced by heavy metal ions and decreased by EDTA. At pH 12.5, the decomposition of the epidioxide is slower than it is near neutrality and ABA is the predominant product. In the biological systems studied the activity of the epidioxide can be accounted for by nonenzymatic conversion to ABA. PMID:16657047

  18. Optical properties of peritoneal biological tissues in the spectral range of 350-2500 nm

    NASA Astrophysics Data System (ADS)

    Bashkatov, A. N.; Genina, E. A.; Kozintseva, M. D.; Kochubei, V. I.; Gorodkov, S. Yu.; Tuchin, V. V.

    2016-01-01

    The optical characteristics of biological tissues sampled from the anterior abdominal wall of laboratory rats are for the first time experimentally studied in a wide wavelength range (350-2500 nm). The experiments have been performed in vitro using a LAMBDA 950 (PerkinElmer, United States) spectrophotometer. Inverse Monte Carlo simulation is used to restore the spectral dependences for scattering and absorption coefficients, as well as the scattering anisotropy factor for biological tissue based on the recorded spectra of diffuse reflection and total and collimated transmissions.

  19. Correlation between structure, retention, property, and activity of biologically relevant 1,7-bis(aminoalkyl)diazachrysene derivatives.

    PubMed

    Šegan, Sandra; Trifković, Jelena; Verbić, Tatjana; Opsenica, Dejan; Zlatović, Mario; Burnett, James; Šolaja, Bogdan; Milojković-Opsenica, Dušanka

    2013-01-01

    The physicochemical properties, retention parameters (R(M)(0)), partition coefficients (logP(OW)), and pK(a) values for a series of thirteen 1,7-bis(aminoalkyl) diazachrysene (1,7-DAAC) derivatives were determined in order to reveal the characteristics responsible for their biological behavior. The investigated compounds inhibit three unrelated pathogens (the Botulinum neurotoxin serotype A light chain (BoNT/A LC), Plasmodium falciparum malaria, and Ebola filovirus) via three different mechanisms of action. To determine the most influential factors governing the retention and activities of the investigated diazachrysenes, R(M)(0), logP(OW), and biological activity values were correlated with 2D and 3D molecular descriptors, using a partial least squares regression. The resulting quantitative structure-retention (property) relationships indicate the importance of descriptors related to the hydrophobicity of the molecules (e.g., predicted partition coefficients and hydrophobic surface area). Quantitative structure-activity relationship models for describing biological activity against the BoNT/A LC and malarial strains also include overall compound polarity, electron density distribution, and proton donor/acceptor potential. Furthermore, models for Ebola filovirus inhibition are presented qualitatively to provide insights into parameters that may contribute to the compounds' antiviral activities. Overall, the models form the basis for selecting structural features that significantly affect the compound's absorption, distribution, metabolism, excretion, and toxicity profiles. PMID:22985530

  20. Biological Properties of Solid Free Form Designed Ceramic Scaffolds with BMP-2: In Vitro and In Vivo Evaluation

    PubMed Central

    Abarrategi, Ander; Moreno-Vicente, Carolina; Martínez-Vázquez, Francisco Javier; Civantos, Ana; Ramos, Viviana; Sanz-Casado, José Vicente; Martínez-Corriá, Ramón; Perera, Fidel Hugo; Mulero, Francisca; Miranda, Pedro; López-Lacomba, José Luís

    2012-01-01

    Porous ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. Solid free form (SFF) fabrication methods allow fabrication of ceramic scaffolds with fully controlled pore architecture, which opens new perspectives in bone tissue regeneration materials. However, little experimentation has been performed about real biological properties and possible applications of SFF designed 3D ceramic scaffolds. Thus, here the biological properties of a specific SFF scaffold are evaluated first, both in vitro and in vivo, and later scaffolds are also implanted in pig maxillary defect, which is a model for a possible application in maxillofacial surgery. In vitro results show good biocompatibility of the scaffolds, promoting cell ingrowth. In vivo results indicate that material on its own conducts surrounding tissue and allow cell ingrowth, thanks to the designed pore size. Additional osteoinductive properties were obtained with BMP-2, which was loaded on scaffolds, and optimal bone formation was observed in pig implantation model. Collectively, data show that SFF scaffolds have real application possibilities for bone tissue engineering purposes, with the main advantage of being fully customizable 3D structures. PMID:22470527

  1. TH-A-19A-05: Modeling Physics Properties and Biologic Effects Induced by Proton and Helium Ions

    SciTech Connect

    Taleei, R; Titt, U; Peeler, C; Guan, F; Mirkovic, D; Grosshans, D; Mohan, R

    2014-06-15

    Purpose: Currently, proton and carbon ions are used for cancer treatment. More recently, other light ions including helium ions have shown interesting physical and biological properties. The purpose of this work is to study the biological and physical properties of helium ions (He-3) in comparison to protons. Methods: Monte Carlo simulations with FLUKA, GEANT4 and MCNPX were used to calculate proton and He-3 dose distributions in water phantoms. The energy spectra of proton and He-3 beams were calculated with high resolution for use in biological models. The repair-misrepairfixation (RMF) model was subsequently used to calculate the RBE. Results: The proton Bragg curve calculations show good agreement between the three general purpose Monte Carlo codes. In contrast, the He-3 Bragg curve calculations show disagreement (for the magnitude of the Bragg peak) between FLUKA and the other two Monte Carlo codes. The differences in the magnitude of the Bragg peak are mainly due to the discrepancy in the secondary fragmentation cross sections used by the codes. The RBE for V79 cell lines is about 0.96 and 0.98 at the entrance of proton and He-3 ions depth dose respectively. The RBE increases to 1.06 and 1.59 at the Bragg peak of proton and He-3 ions. The results demonstrated that LET, microdosimetric parameters (such as dose-mean lineal energy) and RBE are nearly constant along the plateau region of Bragg curve, while all parameters increase within the Bragg peak and at the distal edge for both proton and He-3 ions. Conclusion: The Monte Carlo codes should revise the fragmentation cross sections to more accurately simulate the physical properties of He-3 ions. The increase in RBE for He-3 ions is higher than for proton beams at the Bragg peak.

  2. Characterization of Mechanical and Biological Properties of 3-D Scaffolds Reinforced with Zinc Oxide for Bone Tissue Engineering

    PubMed Central

    Shuai, Cijun; Peng, Shuping

    2014-01-01

    A scaffold for bone tissue engineering should have highly interconnected porous structure, appropriate mechanical and biological properties. In this work, we fabricated well-interconnected porous β-tricalcium phosphate (β-TCP) scaffolds via selective laser sintering (SLS). We found that the mechanical and biological properties of the scaffolds were improved by doping of zinc oxide (ZnO). Our data showed that the fracture toughness increased from 1.09 to 1.40 MPam1/2, and the compressive strength increased from 3.01 to 17.89 MPa when the content of ZnO increased from 0 to 2.5 wt%. It is hypothesized that the increase of ZnO would lead to a reduction in grain size and an increase in density of the strut. However, the fracture toughness and compressive strength decreased with further increasing of ZnO content, which may be due to the sharp increase in grain size. The biocompatibility of the scaffolds was investigated by analyzing the adhesion and the morphology of human osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The scaffolds exhibited better and better ability to support cell attachment and proliferation when the content of ZnO increased from 0 to 2.5 wt%. Moreover, a bone like apatite layer formed on the surfaces of the scaffolds after incubation in simulated body fluid (SBF), indicating an ability of osteoinduction and osteoconduction. In summary, interconnected porous β-TCP scaffolds doped with ZnO were successfully fabricated and revealed good mechanical and biological properties, which may be used for bone repair and replacement potentially. PMID:24498185

  3. Noble metals on the nanoscale: optical and photothermal properties and some applications in imaging, sensing, biology, and medicine.

    PubMed

    Jain, Prashant K; Huang, Xiaohua; El-Sayed, Ivan H; El-Sayed, Mostafa A

    2008-12-01

    Noble metal nanostructures attract much interest because of their unique properties, including large optical field enhancements resulting in the strong scattering and absorption of light. The enhancement in the optical and photothermal properties of noble metal nanoparticles arises from resonant oscillation of their free electrons in the presence of light, also known as localized surface plasmon resonance (LSPR). The plasmon resonance can either radiate light (Mie scattering), a process that finds great utility in optical and imaging fields, or be rapidly converted to heat (absorption); the latter mechanism of dissipation has opened up applications in several new areas. The ability to integrate metal nanoparticles into biological systems has had greatest impact in biology and biomedicine. In this Account, we discuss the plasmonic properties of gold and silver nanostructures and present examples of how they are being utilized for biodiagnostics, biophysical studies, and medical therapy. For instance, taking advantage of the strong LSPR scattering of gold nanoparticles conjugated with specific targeting molecules allows the molecule-specific imaging and diagnosis of diseases such as cancer. We emphasize in particular how the unique tunability of the plasmon resonance properties of metal nanoparticles through variation of their size, shape, composition, and medium allows chemists to design nanostructures geared for specific bio-applications. We discuss some interesting nanostructure geometries, including nanorods, nanoshells, and nanoparticle pairs, that exhibit dramatically enhanced and tunable plasmon resonances, making them highly suitable for bio-applications. Tuning the nanostructure shape (e.g., nanoprisms, nanorods, or nanoshells) is another means of enhancing the sensitivity of the LSPR to the nanoparticle environment and, thereby, designing effective biosensing agents. Metal nanoparticle pairs or assemblies display distance-dependent plasmon resonances as a

  4. Optical anisotropy of fibrous biological tissues: analysis of the influence of structural properties

    SciTech Connect

    Zimnyakov, D A; Sinichkin, Yu P; Ushakova, O V

    2007-08-31

    The results of theoretical analysis of the optical anisotropy of multiply scattering fibrillar biological tissues based on the model of an effective anisotropic medium are compared with the experimental in vivo birefringence data for the rat derma obtained earlier in spectral polarisation measurements of rat skin samples in the visible region. The disordered system of parallel dielectric cylinders embedded into an isotropic dielectric medium was considered as a model medium. Simulations were performed taking into account the influence of a partial mutual disordering of the bundles of collagen and elastin fibres in derma on birefringence in samples. The theoretical optical anisotropy averaged over the spectral interval 550-650 nm for the model medium with parameters corresponding to the structural parameters of derma is in good agreement with the results of spectral polarisation measurements of skin samples in the corresponding wavelength range. (laser methods in biology)

  5. A Remarkably Simple Class of Imidazolium-Based Lipids and Their Biological Properties.

    PubMed

    Wang, Da; Richter, Christian; Rühling, Andreas; Drücker, Patrick; Siegmund, Daniel; Metzler-Nolte, Nils; Glorius, Frank; Galla, Hans-Joachim

    2015-10-19

    A series of imidazolium salts bearing two alkyl chains in the backbone of the imidazolium core were synthesized, resembling the structure of lipids. Their antibacterial activity and cytotoxicity were evaluated using Gram-positive and Gram-negative bacteria and eukaryotic cell lines including tumor cells. It is shown that the length of alkyl chains in the backbone is vital for the antibiofilm activities of these lipid-mimicking components. In addition to their biological activity, their surface activity and their membrane interactions are shown by film balance and quartz crystal microbalance (QCM) measurements. The structure-activity relationship indicates that the distinctive chemical structure contributes considerably to the biological activities of this novel class of lipids. PMID:26332168

  6. Biological control of crystal texture: A widespread strategy for adapting crystal properties to function

    SciTech Connect

    Berman, A.; Leiserowitz, L.; Weiner, S.; Addadi, L. ); Hanson, J.; Koetzle, T.F. )

    1993-02-05

    Textures of calcite crystals from a variety of mineralized tissues belong to organisms from four phyla were examined with high-resolution synchrotron x-ray radiation. Significant differences in coherence length and angular spread were observed between taxonomic groups. Crystals from polycrystalline skeletal ensembles were more perfect than those that function as single-crystal elements. Different anistropic effects on crystal texture were observed for sea urchin and mollusk calcite crystals, whereas none was found for the foraminifer, Patellina, and the control calcite crystals. These results show that the manipulation of crystal texture in different organisms is under biological control and that crystal textures in some tissues are adapted to function. A better understanding of this apparently widespread biological phenomenon may provide new insights for improving synthetic crystal-containing materials. 18 refs., 3 figs., 1 tab.

  7. [Properties and biological effect of dust of various artificial mineral fibers].

    PubMed

    Elovskaja, L T; Werner, I; Kupina, L M; Loscilov, J A; Efremov, L D

    1990-09-01

    Developments and use of man-made mineral fibres are important for the progress in some technical fields. In the last years the number of man-made mineral fibres increased extraordinarily. For the medical evaluation it is necessary to determine the physico-chemical characteristics of the man-made mineral fibre dust and its biological effects in animal experiments. The results of the investigations are described. PMID:2238739

  8. Composting of the solid fraction of digestate derived from pig slurry: Biological processes and compost properties

    SciTech Connect

    Tambone, Fulvia Terruzzi, Laura; Scaglia, Barbara; Adani, Fabrizio

    2015-01-15

    Highlights: • Anaerobic digestion leads to the production of a biologically stable digestate. • Solid–liquid separation produces a solid fraction having high fertilizer value. • Composting process shows low biological activity due to high biological stability of digestate. • Solid digestate fraction can be composted in a short time or used directly as organic fertilizer. - Abstract: The aim of this paper was to assess the characteristics of the solid fractions (SF) obtained by mechanical separation of digestate, their compostability and compost quality. To do so, the SF of digestates obtained from anaerobic digestion of pig slurry, energy crops and agro-industrial residues were sampled in five plants located in Northern Italy. Results obtained indicated that anaerobic digestion by itself promoted the high biological stability of biomasses with a Potential Dynamic Respiration Index (PDRI) close to 1000 mgO{sub 2} kg V S{sup −1} h{sup −1}. Subsequent composting of digestates, with an added bulking agent, did not give remarkably different results, and led only to a slight modification of the characteristics of the initial non-composted mixtures; the composts obtained fully respected the legal limits for high quality compost. Chemical studies of organic matter composition of the biomasses by using CP MAS {sup 13}C NMR, indicated that the compost was composed of a high relative content of O-alkyl-C (71.47% of total C) (cellulose and hemicelluloses) and a low alkyl-C (12.42%) (i.e. volatile fatty acids, steroid-like molecules, aliphatic biopolymers and proteins)

  9. Effect of capping agents: Structural, optical and biological properties of ZnO nanoparticles

    NASA Astrophysics Data System (ADS)

    Javed, Rabia; Usman, Muhammad; Tabassum, Saira; Zia, Muhammad

    2016-11-01

    Different biological activities of capped and uncapped ZnO nanoparticles were investigated, and the effects of potential capping agents on these biological activities were studied. ZnO nanoparticles were synthesized and capped by polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) using a simple chemical method of co-precipitation. Characterization by X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR) and UV-vis spectroscopy confirmed the crystallinity, size, functional group, and band gap of synthesized nanoparticles. Reduction in size occurred from 34 nm to 26 nm due to surfactant. Results of all biological activities indicated significantly higher values in capped as compared to uncapped nanoparticles. Antibacterial activity against Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633), Escherichia coli (ATCC15224), and Acetobacter was obtained. This activity was more prominent against Gram-positive bacteria, and ZnO-PVP nanoparticles elucidated highest antibacterial activity (zone of inhibition 17 mm) against Gram-positive, Bacillus subtilis species. Antioxidant activities including total flavonoid content, total phenolic content, total antioxidant capacity, total reducing power and %age inhibition of DPPH, and antidiabetic activity against α-amylase enzyme found to be exhibited highest by ZnO-PEG nanoparticles.

  10. Effectiveness and properties of the biological prosthesis Permacol™ in pediatric surgery: A large single center experience

    PubMed Central

    Filisetti, Claudia; Costanzo, Sara; Marinoni, Federica; Vella, Claudio; Klersy, Catherine; Riccipetitoni, Giovanna

    2016-01-01

    Introduction The use of prosthetic patches of non-absorbable materials represents a valid tool in the treatment of abdominal wall and diaphragmatic defects in pediatric age. In recent years research has developed biological dermal scaffolds made from a sheet of acellular matrix that can provide the desired support and reduce the occurrence of complications from non-absorbable implant. We present our experience and a systematic review to evaluate the use of biologic prosthesis for abdominal wall closure in pediatric patients. Methods The study from January 2009 to January 2015 involved 20 patients treated with Permacol™ implant. We observed postoperative complications only in patients treated for abdominal wall closure, which is the major indication for the use of Permacol™. We conducted a systematic review and meta-analysis (according to PRISMA) on PubMed/Medline, Scopus and EMBASE regarding the use of biological prosthesis in pediatric population considering the incidence of complications as the primary outcome. Results 3/20 patients experienced complications: 2 patients with skin necrosis healed conservatively and 1 of them developed laparocele. Thus only 1 patient with incisional hernia had significant surgery complication. In patients who were permanently implanted with Permacol™ it has not determined adverse reactions with optimal functional outcome. Conclusions In accordance with the few data (case reports and case series) reported in literature about pediatric patients, our experience in different pathologies and applications has shown the effectiveness of Permacol™, in particular for the non-occurrence of infections, that often affect the use of prosthesis. PMID:27054034

  11. Consistent Robustness Analysis (CRA) Identifies Biologically Relevant Properties of Regulatory Network Models

    PubMed Central

    Saithong, Treenut; Painter, Kevin J.; Millar, Andrew J.

    2010-01-01

    Background A number of studies have previously demonstrated that “goodness of fit” is insufficient in reliably classifying the credibility of a biological model. Robustness and/or sensitivity analysis is commonly employed as a secondary method for evaluating the suitability of a particular model. The results of such analyses invariably depend on the particular parameter set tested, yet many parameter values for biological models are uncertain. Results Here, we propose a novel robustness analysis that aims to determine the “common robustness” of the model with multiple, biologically plausible parameter sets, rather than the local robustness for a particular parameter set. Our method is applied to two published models of the Arabidopsis circadian clock (the one-loop [1] and two-loop [2] models). The results reinforce current findings suggesting the greater reliability of the two-loop model and pinpoint the crucial role of TOC1 in the circadian network. Conclusions Consistent Robustness Analysis can indicate both the relative plausibility of different models and also the critical components and processes controlling each model. PMID:21179566

  12. p-Coumaric acid and its conjugates: dietary sources, pharmacokinetic properties and biological activities.

    PubMed

    Pei, Kehan; Ou, Juanying; Huang, Junqing; Ou, Shiyi

    2016-07-01

    p-Coumaric acid (4-hydroxycinnamic acid) is a phenolic acid that has low toxicity in mice (LD50 = 2850 mg kg(-1) body weight), serves as a precursor of other phenolic compounds, and exists either in free or conjugated form in plants. Conjugates of p-coumaric acid have been extensively studied in recent years due to their bioactivities. In this review, the occurrence, bioavailability and bioaccessibility of p-coumaric acid and its conjugates with mono-, oligo- and polysaccharides, alkyl alcohols, organic acids, amine and lignin are discussed. Their biological activities, including antioxidant, anti-cancer, antimicrobial, antivirus, anti-inflammatory, antiplatelet aggregation, anxiolytic, antipyretic, analgesic, and anti-arthritis activities, and their mitigatory effects against diabetes, obesity, hyperlipaemia and gout are compared. Cumulative evidence from multiple studies indicates that conjugation of p-coumaric acid greatly strengthens its biological activities; however, the high biological activity but low absorption of its conjugates remains a puzzle. © 2015 Society of Chemical Industry. PMID:26692250

  13. Ti-Ag-Pd alloy with good mechanical properties and high potential for biological applications.

    PubMed

    Zadorozhnyy, V Yu; Shi, X; Gorshenkov, M V; Kozak, D S; Wada, T; Louzguine-Luzgin, D V; Inoue, A; Kato, H

    2016-01-01

    Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag-Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy. PMID:27122177

  14. Ti–Ag–Pd alloy with good mechanical properties and high potential for biological applications

    PubMed Central

    Zadorozhnyy, V. Yu.; Shi, X.; Gorshenkov, M. V.; Kozak, D. S.; Wada, T.; Louzguine-Luzgin, D. V.; Inoue, A.; Kato, H.

    2016-01-01

    Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag–Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy. PMID:27122177

  15. Ti–Ag–Pd alloy with good mechanical properties and high potential for biological applications

    NASA Astrophysics Data System (ADS)

    Zadorozhnyy, V. Yu.; Shi, X.; Gorshenkov, M. V.; Kozak, D. S.; Wada, T.; Louzguine-Luzgin, D. V.; Inoue, A.; Kato, H.

    2016-04-01

    Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag–Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy.

  16. Viscoelastic Properties of a Hierarchical Model of Soft Biological Tissue: Two-Dimensional and Three-Dimensional Cases

    NASA Astrophysics Data System (ADS)

    Posnansky, Oleg

    2016-09-01

    The measuring of viscoelastic response is widely used for revealing information about soft matter and biological tissue noninvasively. This information encodes intrinsic dynamic correlations and depends on relations between macroscopic viscoelasticity and structure at the mesoscopic scale. Here we show numerically that the frequency dependent dynamical shear moduli distinguish between the mesoscopic architectural complexities and sensitive to the Euclidean dimensionality. Our approach enables the explanation of two- and three-dimensional viscoelastic experiments by objectively choosing and modeling the most relevant architectural features such as the concentration of compounds and intra-model hierarchical characteristics of physical parameters. Current work provides a link between the macroscopical effective viscoelastic properties to viscoelastic constants and network geometry on the mesoscale. Besides of this we also pay attention to the analytical properties of generalized susceptibility function of considered constitutive model accounting principles of causality.

  17. Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

    PubMed

    Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

    2015-08-01

    Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. PMID:25910818

  18. Toxicant content, physical properties and biological activity of waterpipe tobacco smoke and its tobacco-free alternatives

    PubMed Central

    Shihadeh, Alan; Schubert, Jens; Klaiany, Joanne; El Sabban, Marwan; Luch, Andreas; Saliba, Najat A

    2015-01-01

    Objectives Waterpipe smoking using sweetened, flavoured tobacco products has become a widespread global phenomenon. In this paper, we review chemical, physical and biological properties of waterpipe smoke. Data sources Peer-reviewed publications indexed in major databases between 1991 and 2014. Search keywords included a combination of: waterpipe, narghile, hookah, shisha along with names of chemical compounds and classes of compounds, in addition to terms commonly used in cellular biology and aerosol sizing. Study selection The search was limited to articles published in English which reported novel data on waterpipe tobacco smoke (WTS) toxicant content, biological activity or particle size and which met various criteria for analytical rigour including: method specificity and selectivity, precision, accuracy and recovery, linearity, range, and stability. Data extraction Multiple researchers reviewed the reports and collectively agreed on which data were pertinent for inclusion. Data synthesis Waterpipe smoke contains significant concentrations of toxicants thought to cause dependence, heart disease, lung disease and cancer in cigarette smokers, and includes 27 known or suspected carcinogens. Waterpipe smoke is a respirable aerosol that induces cellular responses associated with pulmonary and arterial diseases. Except nicotine, smoke generated using tobacco-free preparations marketed for ‘health conscious’ users contains the same or greater doses of toxicants, with the same cellular effects as conventional products. Toxicant yield data from the analytical laboratory are consistent with studies of exposure biomarkers in waterpipe users. Conclusions A sufficient evidence base exists to support public health interventions that highlight the fact that WTS presents a serious inhalation hazard. PMID:25666550

  19. YS-822A, a new polyene macrolide antibiotic. I. Production, isolation, characterization and biological properties.

    PubMed

    Itoh, A; Ido, J; Iwamoto, Y; Goshima, E; Miki, T; Hasuda, K; Hirota, H

    1990-08-01

    A new polyene macrolide antibiotic, YS-822A was isolated from the culture filtrate of a mutant strain H-8 of Streptoverticillium eurocidicum var. asterocidicus S-822. Whereas the original S-822 strain produced not only YS-822 substances but also teleocidin as by-product which is well-known as a strong carcinogenic promoter, the mutagenized H-8 strain produced the antibiotic with only a trace amount of teleocidin. Chemical and biological characterizations of the antibiotic revealed that YS-822A (molecular formula: C37H59NO14) is a new polyene macrolide with a wide antifungal spectrum and a low acute toxicity. PMID:2211361

  20. MicroRNA-1 properties in cancer regulatory networks and tumor biology.

    PubMed

    Weiss, Martin; Brandenburg, Lars-Ove; Burchardt, Martin; Stope, Matthias B

    2016-08-01

    Short non-coding microRNAs have been identified to orchestrate crucial mechanisms in cancer progression and treatment resistance. MicroRNAs are involved in posttranscriptional modulation of gene expression and therefore represent promising targets for anticancer therapy. As mircoRNA-1 (miR-1) exerted to be predominantly downregulated in the majority of examined tumors, miR-1 is classified to be a tumor suppressor with high potential to diminish tumor development and therapy resistance. Here we review the complex functionality of miR-1 in tumor biology. PMID:27286699

  1. Modification of some biological properties of HeLa cells containing adeno-associated virus DNA integrated into chromosome 17.

    PubMed Central

    Walz, C; Schlehofer, J R

    1992-01-01

    Parvoviruses are known to interfere with cellular transformation and carcinogenesis. Since infecting adeno-associated virus (AAV) frequently integrates its DNA into the cellular genome, we analyzed whether this integration influences the transformed phenotype of the human tumor cell line HeLa. Analysis of three independent HeLa cell clones with integrated AAV DNA (HA-3x, HA-16, and HA-28) revealed the following phenotypic changes of these cells: (i) reduced growth rate, (ii) increased serum requirement, (iii) reduced capacity for colony formation in soft agar, (iv) reduced cloning efficiency on plastic, (v) elevated sensitivity to genotoxic agents (N-methyl-N'-nitro-N-nitrosoguanidine, 7,12-dimethylbenz[a]anthracene, human tumor necrosis factor alpha, UV irradiation [256 nm], and heat [42 degrees C]), and (vi) reduced sensitivity to the cytolytic effect of parvovirus H-1. Reduced growth rate and enhanced sensitivity to gamma irradiation were also observed in vivo when tumors from AAV DNA-containing HeLa cells were transplanted into nude mice. This alteration of the biological properties of HeLa cells was independent of the number of AAV genomes integrated, the physical structure of integrated AAV DNA, and the transcription of AAV genes. Integration of AAV DNA was found to occur preferentially on the long arm of chromosome 17 in the three HeLa cell clones analyzed. These findings demonstrate that genomic integration of AAV DNA can alter the biological properties of human tumor cells. Images PMID:1313913

  2. The influence of halogen substituents on the biological properties of sulfur-containing flavonoids.

    PubMed

    Bahrin, Lucian Gabriel; Sarbu, Laura Gabriela; Hopf, Henning; Jones, Peter G; Babii, Cornelia; Stefan, Marius; Birsa, Mihail Lucian

    2016-07-15

    A series of halogen-substituted tricyclic flavonoids containing a 1,3-dithiol-2-ylium moiety has been synthesized from the corresponding 3-dithiocarbamic flavanones. The influence of halogen substituents on the antibacterial properties of the tricyclic flavonoids has been investigated against Staphylococcus aureus and Escherichia coli. On going from fluorine to iodine, these compounds exhibit good to excellent inhibitory properties against both Gram-positive and Gram-negative pathogens. These results suggest that size is the main factor for the change in potency rather than polarity/electronics. PMID:27259400

  3. Biochemical Properties and Biological Function of a Monofunctional Microbial Biotin Protein Ligase

    PubMed Central

    Daniels, Kyle G.; Beckett, Dorothy

    2010-01-01

    Biotin protein ligases constitute a family of enzymes that catalyze biotin linkage to biotin-dependent carboxylases. In bacteria these enzymes are functionally divided into two classes; the monofunctional enzymes that only catalyze biotin addition and the bifunctional enzymes that also bind to DNA to regulate transcription initiation. Biochemical and biophysical studies of the bifunctional Escherichia coli ligase suggest that several properties of the enzyme have evolved to support its additional regulatory role. Included among these properties are the order of substrate binding and linkage between oligomeric state and ligand binding. PMID:20499837

  4. Properties of Resveratrol: In Vitro and In Vivo Studies about Metabolism, Bioavailability, and Biological Effects in Animal Models and Humans

    PubMed Central

    Gambini, J.; Inglés, M.; Olaso, G.; Lopez-Grueso, R.; Bonet-Costa, V.; Gimeno-Mallench, L.; Mas-Bargues, C.; Abdelaziz, K. M.; Gomez-Cabrera, M. C.; Vina, J.; Borras, C.

    2015-01-01

    Plants containing resveratrol have been used effectively in traditional medicine for over 2000 years. It can be found in some plants, fruits, and derivatives, such as red wine. Therefore, it can be administered by either consuming these natural products or intaking nutraceutical pills. Resveratrol exhibits a wide range of beneficial properties, and this may be due to its molecular structure, which endow resveratrol with the ability to bind to many biomolecules. Among these properties its activity as an anticancer agent, a platelet antiaggregation agent, and an antioxidant, as well as its antiaging, antifrailty, anti-inflammatory, antiallergenic, and so forth activities, is worth highlighting. These beneficial biological properties have been extensively studied in humans and animal models, both in vitro and in vivo. The issue of bioavailability of resveratrol is of paramount importance and is determined by its rapid elimination and the fact that its absorption is highly effective, but the first hepatic step leaves little free resveratrol. Clarifying aspects like stability and pharmacokinetics of resveratrol metabolites would be fundamental to understand and apply the therapeutic properties of resveratrol. PMID:26221416

  5. Study of the surface wear resistance and biological properties of the Ti-Zr-Nb-Sn alloy for dental restoration.

    PubMed

    Hu, Xin; Wei, Qiang; Li, Chang-Yi; Deng, Jia-Yin; Liu, Shuang; Zhang, Lian-Yun

    2010-10-01

    A new titanium alloy (Ti-12.5Zr-3Nb-2.5Sn) was developed to meet the needs of clinical requirements for medical titanium alloys and improve the properties of existing titanium alloys. The as-prepared alloy was solution treated at 500 °C for 3 h in vacuum followed by water quenching. Tensile, wear and hardness tests were carried out to examine the mechanical properties of the Ti-Zr-Nb-Sn alloy. Oral mucous membrane irritation test was performed to evaluate the surface biological properties of the Ti-Zr-Nb-Sn alloy. The results suggested that the surface hardness and wear-resistant properties of the Ti-12.5Zr-3Nb-2.5Sn alloy were superior to commercially pure Ti. The oral mucous irritation test showed that all samples had no mucous membrane irritation. It indicates that Ti-12.5Zr-3Nb-2.5Sn has large potential to be used as dental restoration material. PMID:20876964

  6. Preparation, characterization, and biological properties of organic-inorganic nanocomposite coatings on titanium substrates prepared by sol-gel.

    PubMed

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando

    2014-02-01

    When surface-reactive (bioactive) coatings are applied to medical implants by means of the sol-gel dip-coating technique, the biological proprieties of the surface of the implant can be locally modified to match the properties of the surrounding tissues to provide a firm fixation of the implant. The aim of this study has been to synthesize, via sol-gel, organoinorganic nanoporous materials and to dip-coat a substrate to use in dental applications. Different systems have been prepared consisting of an inorganic zirconium-based matrix, in which a biodegradable polymer, the poly-ε-caprolactone was incorporated in different percentages. The materials synthesized by the sol-gel process, before gelation, when they were still in sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to change its surface biological properties. Thin films have been obtained by means of the dip-coating technique. A microstructural analysis of the obtained coatings was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. The biological proprieties have been investigated by means of tests in vitro. The bone-bonding capability of the nanocomposite films has been evaluated by examining the appearance of apatite on their surface when plunged in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. The examination of apatite formation on the nanocomposites, after immersion in SBF, has been carried out by SEM equipped with energy-dispersive X-ray spectroscopy. To evaluate cells-materials interaction, human osteosarcoma cell line (Saos-2) has been seeded on specimens and cell vitality evaluated by WST-8 assay. PMID:23533196

  7. Borreria and Spermacoce species (Rubiaceae): A review of their ethnomedicinal properties, chemical constituents, and biological activities

    PubMed Central

    Conserva, Lucia Maria; Ferreira, Jesu Costa

    2012-01-01

    Borreira and Spermacoce are genera of Rubiaceae widespread in tropical and subtropical America, Africa, Asia, and Europe. Based on its fruits morphology they are considered by many authors to be distinct genera and most others, however, prefer to combine the two taxa under the generic name Spermacoce. Whereas the discussion is still unclear, in this work they were considered as synonyms. Some species of these genera play an important role in traditional medicine in Africa, Asia, Europe, and South America. Some of these uses include the treatment of malaria, diarrheal and other digestive problems, skin diseases, fever, hemorrhage, urinary and respiratory infections, headache, inflammation of eye, and gums. To date, more than 60 compounds have been reported from Borreria and Spermacoce species including alkaloids, iridoids, flavonoids, terpenoids, and other compounds. Studies have confirmed that extracts from Borreria and Spermacoce species as well as their isolated compounds possess diverse biological activities, including anti-inflammatory, antitumor, antimicrobial, larvicidal, antioxidant, gastrointestinal, anti-ulcer, and hepatoprotective, with alkaloids and iridoids as the major active principles. This paper briefly reviews the ethnomedicinal uses, phytochemistry, and biological activities of some isolated compounds and extracts of both genera. PMID:22654404

  8. Mount St. Helens Ash from the 18 May 1980 Eruption: Chemical, Physical, Mineralogical, and Biological Properties

    NASA Astrophysics Data System (ADS)

    Fruchter, Jonathan S.; Robertson, David E.; Evans, John C.; Olsen, Khris B.; Lepel, Elwood A.; Laul, Jagdish C.; Abel, Keith H.; Sanders, Ronald W.; Jackson, Peter O.; Wogman, Ned S.; Perkins, Richard W.; van Tuyl, Harold H.; Beauchamp, Raymond H.; Shade, John W.; Leland Daniel, J.; Erikson, Robert L.; Sehmel, George A.; Lee, Richard N.; Robinson, Alfred V.; Moss, Owen R.; Briant, James K.; Cannon, William C.

    1980-09-01

    Samples of ash from the 18 May 1980 eruption of Mount St. Helens were collected from several locations in eastern Washington and Montana. The ash was subjected to a variety of analyses to determine its chemical, physical, mineralogical, and biological characteristics. Chemically, the ash samples were of dacitic composition. Particle size data showed bimodal distributions and differed considerably with location. However, all samples contained comparable amounts of particles less than 3.5 micrometers in diameter (respirable fraction). Mineralogically, the samples ranged from almost totally glassy to almost totally crystalline. Crystalline samples were dominated by plagioclase feldspar (andesine) and orthopyroxene (hypersthene), with smaller amounts of titanomagnetite and hornblende. All but one of the samples contained from less than 1 percent to 3 percent free crystalline silica (quartz, trydimite, or cristobalite) in both the bulk samples and 1 to 2 percent in the fractions smaller than 3.5 micrometers. The long-lived natural radionuclide content of the ash was comparable to that of crustal material; however, relatively large concentrations of short-lived radon daughters were present and polonium-210 content was inversely correlated with particle size. In vitro biological tests showed the ash to be nontoxic to alveolar macrophages, which are an important part of the lungs' natural clearance mechanism. On the basis of a substantial body of data that has shown a correlation between macrophage cytotoxicity and fibrogenicity of minerals, the ash is not predicted to be highly fibrogenic.

  9. Two New “Protected” Oxyphors for Biological Oximetry: Properties and Application in Tumor Imaging

    PubMed Central

    Esipova, Tatiana V.; Karagodov, Alexander; Miller, Joann; Wilson, David F.; Busch, Theresa M.; Vinogradov, Sergei A.

    2013-01-01

    We report the synthesis, calibration, and examples of application of two new phosphorescent probes, Oxyphor R4 and Oxyphor G4, optimized specifically for in vivo oxygen imaging by phosphorescence quenching. These “protected” dendritic probes can operate in either albumin-rich (blood plasma) or albumin-free (interstitial space) environments at all physiological oxygen concentrations, from normoxic to deep hypoxic conditions. Oxyphors R4 and G4 are derived from phosphorescent Pd-meso-tetra-(3,5-dicarboxyphenyl)-porphyrin (PdP) or Pd-meso-tetra-(3,5-dicarboxyphenyl)-tetrabenzoporphyrin (PdTBP), respectively, and possess features common for protected dendritic probes, i.e., hydrophobic dendritic encapsulation of phosphorescent metalloporphyrins and hydrophilic PEGylated periphery. The new Oxyphors are highly soluble in aqueous environments and do not permeate biological membranes. The probes were calibrated under physiological conditions (pH 6.4–7.8) and temperatures (22–38 °C), showing high stability, reproducibility of signals, and lack of interactions with biological solutes. Oxyphor G4 was used to dynamically image intravascular and interstitial oxygenation in murine tumors in vivo. The physiological relevance of the measurements was demonstrated by dynamically recording changes in tissue oxygenation during application of anesthesia (isofluorane). These experiments revealed that changes in isofluorane concentration significantly affect tissue oxygenation. PMID:21961699

  10. Mount St. Helens ash from the 18 May 1980 eruption: chemical, physical, mineralogical, and biological properties

    SciTech Connect

    Fruchter, J.S.; Robertson, D.E.; Evans, J.C.

    1980-09-05

    Samples of ash from the 18 May 1980 eruption of Mount St. Helens were collected from several locations in eastern Washington and Montana. The ash was subjected to a variety of analyses to determine its chemical, physical, mineralogical, and biological characteristics. Chemically, the ash samples were of dacitic composition. Particle size data showed bimodal distributions and differed considerably with location. However, all samples contained comparable amounts of particles less than 3.5 micrometers in diameter (respirable fraction). Mineralogically, the samples ranged from almost totally glassy to almost totally crystalline. Crystalline samples were dominated by plagioclase feldspar (andesine) and orthopyroxene (hypersthene), with smaller amounts of titanomagnetite and hornblende. All but one of the samples contained from less than 1% to 3% free crystalline silica (quartz, trydimite, or cristobalite) in both the bulk samples and 1 to 2% in the fractions smaller than 3.5 micrometers. The long-lived natural radionuclide content of the ash was comparable to that of crustal material; however, relatively large concentrations of short-lived radon daughters were present and polonium-210 content was inversely correlated with particle size. In vitro biological tests showed the ash to be nontoxic to alveolar macrophages, which are an important pat of the lungs' natural clearance mechanism. On the basis of a substantial body of data that has shown a correlation between macrophage cytotoxicity and fibrogenicity of minerals, the ash is not predicted to be highly fibrogenic.

  11. Lorentz contact resonance spectroscopy for nanoscale characterisation of structural and mechanical properties of biological, dental and pharmaceutical materials.

    PubMed

    Khanal, Dipesh; Dillon, Eoghan; Hau, Herman; Fu, Dong; Ramzan, Iqbal; Chrzanowski, Wojciech

    2015-12-01

    Scanning probe microscopy has been widely used to obtain topographical information and to quantify nanostructural properties of different materials. Qualitative and quantitative imaging is of particular interest to study material-material interactions and map surface properties on a nanoscale (i.e. stiffness and viscoelastic properties). These data are essential for the development of new biomedical materials. Currently, there are limited options to map viscoelastic properties of materials at nanoscale and at high resolutions. Lorentz contact resonance (LCR) is an emerging technique, which allows mapping viscoelasticity of samples with stiffness ranging from a few hundred Pa up to several GPa. Here we demonstrate the applicability of LCR to probe and map the viscoelasticity and stiffness of 'soft' (biological sample: cell treated with nanodiamond), 'medium hard' (pharmaceutical sample: pMDI canister) and 'hard' (human teeth enamel) specimens. The results allowed the identification of nanodiamond on the cells and the qualitative assessment of its distribution based on its nanomechanical properties. It also enabled mapping of the mechanical properties of the cell to demonstrate variability of these characteristics in a single cell. Qualitative imaging of an enamel sample demonstrated variations of stiffness across the specimen and precise identification of enamel prisms (higher stiffness) and enamel interrods (lower stiffness). Similarly, mapping of the pMDI canister wall showed that drug particles were adsorbed to the wall. These particles showed differences in stiffness at nanoscale, which suggested variations in surface composition-multiphasic material. LCR technique emerges as a valuable tool for probing viscoelasticity of samples of varying stiffness's. PMID:26518012

  12. Structure-Property-Function Relationship in Humic Substances to Explain the Biological Activity in Plants

    PubMed Central

    García, Andrés Calderín; de Souza, Luiz Gilberto Ambrosio; Pereira, Marcos Gervasio; Castro, Rosane Nora; García-Mina, José María; Zonta, Everaldo; Lisboa, Francy Junior Gonçalves; Berbara, Ricardo Luis Louro

    2016-01-01

    Knowledge of the structure-property-function relationship of humic substances (HSs) is key for understanding their role in soil. Despite progress, studies on this topic are still under discussion. We analyzed 37 humic fractions with respect to their isotopic composition, structural characteristics, and properties responsible for stimulating plant root parameters. We showed that regardless of the source of origin of the carbon (C3 or C4), soil-extracted HSs and humic acids (HAs) are structurally similar to each other. The more labile and functionalized HS fraction is responsible for root emission, whereas the more recalcitrant and less functionalized HA fraction is related to root growth. Labile structures promote root stimulation at lower concentrations, while recalcitrant structures require higher concentrations to promote a similar stimulus. These findings show that lability and recalcitrance, which are derived properties of humic fractions, are related to the type and intensity of their bioactivity. In summary, the comparison of humic fractions allowed a better understanding of the relationship between the source of origin of plant carbon and the structure, properties, and type and intensity of the bioactivity of HSs in plants. In this study, scientific concepts are unified and the basis for the agronomic use of HSs is established. PMID:26862010

  13. Chemical, physical, and biological properties of compounds present at hazardous-waste sites. Final report

    SciTech Connect

    Not Available

    1985-09-27

    The chemical profiles are intended to serve as a concise reference with information on the physicochemical properties, transport and fate, toxicity, and regulatory standards for individual chemicals identified by the EPA Office of Waste Program Enforcement at hazardous-waste sites. The profiles can be used in conjunction with the Toxicology and Endangerment Assessment Handbooks.

  14. Structure-Property-Function Relationship in Humic Substances to Explain the Biological Activity in Plants.

    PubMed

    García, Andrés Calderín; de Souza, Luiz Gilberto Ambrosio; Pereira, Marcos Gervasio; Castro, Rosane Nora; García-Mina, José María; Zonta, Everaldo; Lisboa, Francy Junior Gonçalves; Berbara, Ricardo Luis Louro

    2016-01-01

    Knowledge of the structure-property-function relationship of humic substances (HSs) is key for understanding their role in soil. Despite progress, studies on this topic are still under discussion. We analyzed 37 humic fractions with respect to their isotopic composition, structural characteristics, and properties responsible for stimulating plant root parameters. We showed that regardless of the source of origin of the carbon (C3 or C4), soil-extracted HSs and humic acids (HAs) are structurally similar to each other. The more labile and functionalized HS fraction is responsible for root emission, whereas the more recalcitrant and less functionalized HA fraction is related to root growth. Labile structures promote root stimulation at lower concentrations, while recalcitrant structures require higher concentrations to promote a similar stimulus. These findings show that lability and recalcitrance, which are derived properties of humic fractions, are related to the type and intensity of their bioactivity. In summary, the comparison of humic fractions allowed a better understanding of the relationship between the source of origin of plant carbon and the structure, properties, and type and intensity of the bioactivity of HSs in plants. In this study, scientific concepts are unified and the basis for the agronomic use of HSs is established. PMID:26862010

  15. A Comprehensive Review of Punica granatum (Pomegranate) Properties in Toxicological, Pharmacological, Cellular and Molecular Biology Researches

    PubMed Central

    Rahimi, Hamid Reza; Arastoo, Mohammad; Ostad, Seyed Nasser

    2012-01-01

    Punica granatum (Pg), commonly known as pomegranate (Pg), is a member of the monogeneric family, Punicaceae, and is mainly found in Iran which is considered to be its primary centre of origin. Pg and its chemical components possess various pharmacological and toxicological properties including antioxidant, anti-inflammatory (by inhibiting pro-inflammatory cytokines), anti-cancer and anti-angiogenesis activities. They also show inhibitory effects on invasion/motility, cell cycle, apoptosis, and vital enzymes such as cyclooxygenase (COX), lipooxygenase (LOX), cytochrome P450 (CYP450), phospholipase A2 (PLA2), ornithine decarboxylase (ODC), carbonic anhydrase (CA), 17beta-hydroxysteroid dehydrogenase (17β-HSDs) and serine protease (SP). Furthermore, they can stimulate cell differentiation and possess anti-mutagenic effects. Pg can also interfere with several signaling pathways including PI3K/AKT, mTOR, PI3K, Bcl-X, Bax, Bad, MAPK, ERK1/2, P38, JNK, and caspase. However, the exact mechanisms for its pharmacological and toxicological properties remain to be unclear and need further evaluation. These properties strongly suggest a wide range use of Pg for clinical applications. This review will discuss the areas for which Pg has shown therapeutic properties in different mechanisms. PMID:24250463

  16. Structure-Property-Function Relationship in Humic Substances to Explain the Biological Activity in Plants

    NASA Astrophysics Data System (ADS)

    García, Andrés Calderín; de Souza, Luiz Gilberto Ambrosio; Pereira, Marcos Gervasio; Castro, Rosane Nora; García-Mina, José María; Zonta, Everaldo; Lisboa, Francy Junior Gonçalves; Berbara, Ricardo Luis Louro

    2016-02-01

    Knowledge of the structure-property-function relationship of humic substances (HSs) is key for understanding their role in soil. Despite progress, studies on this topic are still under discussion. We analyzed 37 humic fractions with respect to their isotopic composition, structural characteristics, and properties responsible for stimulating plant root parameters. We showed that regardless of the source of origin of the carbon (C3 or C4), soil-extracted HSs and humic acids (HAs) are structurally similar to each other. The more labile and functionalized HS fraction is responsible for root emission, whereas the more recalcitrant and less functionalized HA fraction is related to root growth. Labile structures promote root stimulation at lower concentrations, while recalcitrant structures require higher concentrations to promote a similar stimulus. These findings show that lability and recalcitrance, which are derived properties of humic fractions, are related to the type and intensity of their bioactivity. In summary, the comparison of humic fractions allowed a better understanding of the relationship between the source of origin of plant carbon and the structure, properties, and type and intensity of the bioactivity of HSs in plants. In this study, scientific concepts are unified and the basis for the agronomic use of HSs is established.

  17. Rheological properties of a biological thermo-responsive hydrogel prepared from vegetable oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogel is a colloidal gel in which water is the dispersion medium. The unique properties of hydrogels make this kind of materials have many utilization potentials, such as drug delivery, gene therapy, wound care products, breast implant materials, cosmetic products, and tissue engineering. Hydroge...

  18. Sequence-dependent collective properties of DNAs and their role in biological systems

    NASA Astrophysics Data System (ADS)

    De Santis, Pasquale; Scipioni, Anita

    2013-03-01

    DNA actively interacts with proteins involved in replication, transcription, repair, and regulation processes inside the cell. The base sequence encodes the dynamics of these transformations from the atomic to the nanometre scale length, and over higher spatial scales. In fact, although an important part of the DNA informational content acts locally, it exerts its functions as collective properties of relatively long sequences and manifests as static and dynamic curvature. Physical models that explore different aspects of DNA collective properties associated to such superstructural properties encoded in the sequence will be reviewed. The B-DNA periodicity operates as band-pass-filter; only the local physical-chemical variance associated to the sequence, in phase with the helical periodicity, sums up and reveals at higher scale. In this light, the gel electrophoresis behaviour of DNAs, the nucleosome thermodynamic stability and positioning along genomes were interpreted and discussed. Finally, a part of this review is reserved to describe the ability of some inorganic crystal surfaces to recognize and stabilize certain DNA tracts with peculiar sequences. The collective superstructural properties of DNAs could be involved in the selective interaction between DNA sequence and particular crystal surfaces. It may be conceived that sequences strongly adsorbed on surface could nucleate and expand bits of information in primeval DNA (and/or RNA) chains, early characterized by random sequences, since more protected against the physical-chemical injuries by the environment, and therefore involved in the evolution of their informational content.

  19. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using Harmonic Motion Imaging (HMI)

    NASA Astrophysics Data System (ADS)

    Vappou, Jonathan; Hou, Gary Y.; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E.

    2015-04-01

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young’s modulus and the HMI modulus in the numerical study (r2 > 0.99, relative error <10%) and on polyacrylamide gels (r2 = 0.95, relative error <24%). The average HMI modulus on five liver samples was found to EHMI = 2.62  ±  0.41 kPa, compared to EMechTesting = 4.2  ±  2.58 kPa measured by rheometry. This study has demonstrated for the first time the initial feasibility of a non-invasive, model-independent method to estimate local elastic properties of biological tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens.

  20. Non-contact, Ultrasound-based Indentation Method for Measuring Elastic Properties of Biological Tissues Using Harmonic Motion Imaging (HMI)

    PubMed Central

    Vappou, Jonathan; Hou, Gary Y.; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E.

    2015-01-01

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by Harmonic Motion Imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking RF signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the actual Young’s modulus and the HMI modulus in the numerical study (r2>0.99, relative error <10%) and on polyacrylamide gels (r2=0.95, relative error <24%). The average HMI modulus on five liver samples was found to EHMI=2.62±0.41 kPa, compared to EMechTesting=4.2±2.58 kPa measured by rheometry. This study has demonstrated for the first time the initial feasibility of a non-invasive, model-independent method to estimate local elastic properties of biological tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens. PMID:25776065

  1. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    PubMed

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  2. Effects of seasonal olive mill wastewater applications on hydrological and biological soil properties in an olive orchard in Israel

    NASA Astrophysics Data System (ADS)

    Steinmetz, Zacharias; Kurtz, Markus; Peikert, Benjamin; Zipori, Isaac; Dag, Arnon; Schaumann, Gabriele E.

    2014-05-01

    During olive oil production in Mediterranean countries, large amounts of olive mill wastewater (OMW) are generated within a short period of time. OMW has a high nutrient content and could serve as fertilizer when applied on land. However, its fatty and phenolic constituents have adverse effects on hydrological and biological soil properties. It is still unknown how seasonal fluctuations in temperature and precipitation influence the fate and effect of OMW components on soil in a long-term perspective. An appropriate application season could mitigate negative consequences of OMW while preserving its beneficial effects. In order to investigate this, 14 L OMW m-2 were applied to different plots of an olive orchard in Gilat, Israel, in winter, spring, and summer, respectively. Hydrological soil properties (water drop penetration time, hydraulic conductivity, dynamic contact angle), physicochemical parameters (pH, EC, soluble ions, phenolic compounds, organic matter), and biological degradation (bait-lamina test) were measured to assess the soil state after OMW application. After one rainy season following OMW application, the soil quality of summer treatments significantly decreased compared to the control. This was particularly apparent in a ten-fold higher soil water repellency, a three-times lower biodegradation performance, and a four-fold higher content of phenolic compounds. 1.5 years after the last OMW application, the soil properties of winter treatments were comparable to the control, which suggests a certain recovery potential of the soil. Spring treatments resulted in an intermediate response compared to summer and winter treatments, but without any precipitation following OMW application. Strongest OMW effects were found in the top soil layers. Further research is needed to quantify the effect of spring treatments as well as to gain further insight into leaching effects, the composition of organic OMW constituents, and the kinetics of their degradation in

  3. Mars Primordial Crust: Unique Sites for Investigating Proto-biologic Properties

    NASA Astrophysics Data System (ADS)

    Perry, Randall S.; Hartmann, William K.

    2006-12-01

    The Martian meteorite collection suggests that intact outcrops or boulder-scale fragments of the 4.5 Ga Martian crust exist within tens of meters of the present day surface of Mars. Mars may be the only planet where such primordial crust samples, representing the first 100 Ma of a planet’s environment, are available. The primordial crust has been destroyed on Earth by plate tectonics and other geological phenomena and is buried on the Moon under hundreds or thousands of meters of megaregoltih. Early Mars appears to have been remarkably similar to early Earth, and samples of rock from the first few Ma or first 100 Ma may reveal “missing link” proto-biological forms that could shed light on the transition from abiotic organic chemistry to living cells. Such organic snapshots of nascent life are unlikely to be found on Earth.

  4. Investigation on biological properties of tacrolimus-loaded poly(1,3-trimethylene carbonate) in vitro

    NASA Astrophysics Data System (ADS)

    Hou, Ruixia; Wu, Leigang; Wang, Jin; Huang, Nan

    2010-06-01

    The drug-eluting stents have been regarded as a milestone in inhibiting the restenosis of coronary arteries. However, adverse reactions caused by bare-metal stents and non-biodegradable polymer coatings may result in some clinical problems. In this study, a new tacrolimus-eluting stent coated with biodegradable poly(1,3-trimethylene carbonate) (PTMC) is developed. The structures are characterized by Fourier transform infrared (FTIR) analysis, and the wettability is measured by contact angle assay. The biological behaviors are evaluated by the in vitro platelets adhesion test, APTT test, the human umbilical cord artery smooth muscle cells (HUCASMCs), 4',6-diamidine-2-phenylindole (DAPI) and actin immunofluorescence staining, MTT colorimetric assay. These results show that after blending tacrolimus into PTMC, the anticoagulant behavior is improved, and the adhesion and proliferation of HUCASMCs on samples are inhibited. This work aims to find one kind of surface erosion biodegradable polymers that can be applied as drug-eluting stent coatings.

  5. (/sup 125/I)diiodoinsulins. Binding affinities, biologic potencies, and properties of their decay products

    SciTech Connect

    Perez Maceda, B.; Linde, S.; Sonne, O.; Gliemann, J.

    1982-07-01

    Insulin was iodinated with 0.3-0.4 mol /sup 125/I/mol insulin using the lactoperoxidase method. About one-third of the radioactivity incorporated into insulin was in diiodoinsulins and about 40% of these molecules contained diiodotyrosine in residue 14 of the A chain. Most of the remaining molecules contained one A14-monoiodotyrosine and one monoiodotyrosine in either position A19, B16, or B26. The binding affinity and biologic potency of this heterogeneous diiodoinsulin preparation was not significantly different from that of A14-(/sup 125/I)monoiodoinsulin in rat adipocytes, whereas it was slightly reduced in hepatocytes and IM-9 lymphocytes. From the iodine distribution and previous data on the binding affinity of each of the four monoiodoinsulin isomers it was calculated that A14-diiodotyrosine-insulin possesses full binding affinity and biologic potency in adipocytes. Diiodoinsulins isolated from another iodoinsulin preparation (iodate method) contained 58% A19-diiodotyrosine-insulin, and most remaining molecules contained one A19-monoiodotyrosine. The binding affinity of this mixed diiodoinsulin preparation was approximately one-fourth of that of A14-monoiodoinsulin in adipocytes, IM-9 lymphocytes, and hepatocytes. It was calculated that A19-diiodotyrosine-insulin is nearly devoid of binding affinity. The diiodoinsulins (lactoperoxidase method) decayed to iodide (probably from diiodotyrosine-insulin) or to polymers with little specific but a markedly increased nonspecific binding. In addition, the polymers had a marked tendency to adsorb to cellulose acetate filters. Conclusions: 1. The binding affinities of diiodoinsulins range from very low values to values at least as high as that of insulin depending on the positions of the iodine moieties. 2. The relative binding affinities vary among tissues. 3. Polymeric decay products give high nonspecific binding.

  6. An examination of the structural and biological properties of three intravenous immunoglobulin preparations.

    PubMed

    Law, D T; Painter, R H

    1986-03-01

    Three commercial preparations of immunoglobulin G prepared for administration by the i.v. route were tested for their physical integrity and in vitro biological activity. Size exclusion chromatography by HPLC in native and denaturing buffers together with SDS-PAGE analysis were used to determine whether covalent-bond cleavage had occurred as a result of procedures used in their preparation. C1 complement binding assays and measurements of competitive binding to an Fc receptor-bearing promonocyte cell line U937 were used to assess whether such changes had altered the capacity of these preparations to engage biological effector functions. A purified IgG1 myeloma protein was used as a reference standard. WinRho, an unmodified IgG, consisted almost wholly of monomeric IgG by HPLC size exclusion and showed no evidence of proteolytic fragments in denaturing buffers or on SDS-PAGE. Sandoglobulin, a product treated at pH 4 with pepsin, contained about 10% dimeric protein and, as revealed under denaturing conditions, about 2% fragments. Relative affinity of binding to U937 cells was similar to WinRho. C1 binding by Sandoglobulin showed normal activity with 50% inhibition at 2.8 nM. Gamimune, modified by partial reduction and alkylation, contained about 15% dimers. Between 20 and 30% of the preparation retained covalent interchain disulfides. Binding to U937 cells was two-fold weaker than the other preparations and binding to C1 was also diminished and modified. This accords well with previous reports of the deleterious effect of reduction and alkylation on Fc function. PMID:3713708

  7. Short cationic lipopeptides as effective antibacterial agents: Design, physicochemical properties and biological evaluation.

    PubMed

    Azmi, Fazren; Elliott, Alysha G; Marasini, Nirmal; Ramu, Soumya; Ziora, Zyta; Kavanagh, Angela M; Blaskovich, Mark A T; Cooper, Matthew A; Skwarczynski, Mariusz; Toth, Istvan

    2016-05-15

    The spread of drug-resistant bacteria has imparted a sense of urgency in the search for new antibiotics. In an effort to develop a new generation of antibacterial agents, we have designed de novo charged lipopeptides inspired by natural antimicrobial peptides. These short lipopeptides are composed of cationic lysine and hydrophobic lipoamino acids that replicate the amphiphilic properties of natural antimicrobial peptides. The resultant lipopeptides were found to self-assemble into nanoparticles. Some were effective against a variety of Gram-positive bacteria, including strains resistant to methicillin, daptomycin and/or vancomycin. The lipopeptides were not toxic to human kidney and liver cell lines and were highly resistant to tryptic degradation. Transmission electron microscopy analysis of bacteria cells treated with lipopeptide showed membrane-damage and lysis with extrusion of cytosolic contents. With such properties in mind, these lipopeptides have the potential to be developed as new antibacterial agents against drug-resistant Gram-positive bacteria. PMID:27048775

  8. Correlative study of properties of water in biological systems using ultrasound and magnetic resonance.

    PubMed

    Sehgal, C M; Greenleaf, J F

    1986-12-01

    Ultrasonic and nuclear magnetic resonance properties of media rich in water are investigated. The chemical shift of the water proton in pure water, aqueous solutions of tertiary butanol, and sodium chloride is shown to be linearly correlated to the reciprocal of sound speed in these media. A new method of determining the self-diffusion coefficient of water by using acoustic nonlinearity and sound speed is proposed. The method is tested on a variety of media that include pure water, aqueous solutions of glycerol, serum albumin, egg constituents, plant tissues, frog muscle and liver, and excised human tissues. In all the cases the results are found to compare closely to diffusion coefficients measured by magnetic resonance. The results presented here indicate that the acoustic and magnetic resonance modalities, though inherently different in their origin, can provide closely related information on the properties of water. PMID:3821474

  9. Exploiting the Physicochemical Properties of Dendritic Polymers for Environmental and Biological Applications

    SciTech Connect

    Bhattacharya, Priyanka; Geitner, Nicholas K.; Sarupria, Sapna; Ke, Pu Chun

    2013-04-07

    In this Perspective we first examine the rich physicochemical properties of dendritic polymers for hosting cations, anions, and polyaromatic hydrocarbons. We then extrapolate these conceptual discussions to the use of dendritic polymers for humic acid antifouling, oil dispersion, copper sensing, and fullerenol remediation. In addition, we review the state-of-the-art of dendrimer research and elaborate on their 10 implications for water purification, environmental remediation, nanomedicine, and energy harvesting.

  10. Plankton and particle size and packaging: from determining optical properties to driving the biological pump.

    PubMed

    Stemmann, L; Boss, E

    2012-01-01

    Understanding pelagic ecology and quantifying energy fluxes through the trophic web and from the surface to the deep ocean requires the ability to detect and identify all organisms and particles in situ and in a synoptic manner. An idealized sensor should observe both the very small living or dead particles such as picoplankton and detritus, respectively, and the large particles such as aggregates and meso- to macroplankton. Such an instrument would reveal an astonishing amount and diversity of living and nonliving particles present in a parcel of water. Unfortunately such sensors do not exist. However, complex interactions constrain the space, temporal, and size distributions of these objects in such ways that general rules can be inferred from the measurement of their optical properties. Recent technological developments allow for the in situ measurement of the optical properties and size distributions of particles and plankton in a way such that synoptic surveys are possible. This review deals with particle and plankton size distributions (PSDs) as well as how particles' geometry and nature affect their optical properties. Finally, we propose the integration of the PSD into size-structured mathematical models of biogeochemical fluxes. PMID:22457976

  11. Improving fundamental abilities of atomic force microscopy for investigating quantitative nanoscale physical properties of complex biological systems

    NASA Astrophysics Data System (ADS)

    Cartagena-Rivera, Alexander X.

    Measurements of local material properties of complex biological systems (e.g. live cells and viruses) in their respective physiological conditions are extremely important in the fields of biophysics, nanotechnology, material science, and nanomedicine. Yet, little is known about the structure-function-property relationship of live cells and viruses. In the case of live cells, the measurements of progressive variations in viscoelastic properties in vitro can provide insight to the mechanistic processes underpinning morphogenesis, mechano-transduction, motility, metastasis, and many more fundamental cellular processes. In the case of living viruses, the relationship between capsid structural framework and the role of the DNA molecule interaction within viruses influencing their stiffness, damping and electrostatic properties can shed light in virological processes like protein subunits assembly/dissassembly, maturation, and infection. The study of mechanics of live cells and viruses has been limited in part due to the lack of technology capable of acquiring high-resolution (nanoscale, subcellular) images of its heterogeneous material properties which vary widely depending on origin and physical interaction. The capabilities of the atomic force microscope (AFM) for measuring forces and topography with sub-nm precision have greatly contributed to research related to biophysics and biomechanics during the past two decades. AFM based biomechanical studies have the unique advantage of resolving/mapping spatially the local material properties over living cells and viruses. However, conventional AFM techniques such as force-volume and quasi-static force-distance curves are too low resolution and low speed to resolve interesting biophysical processes such as cytoskeletal dynamics for cells or assembly/dissasembly of viruses. To overcome this bottleneck, a novel atomic force microscopy mode is developed, that leads to sub-10-nm resolution and sub-15-minutes mapping of local

  12. A Monte-Carlo maplet for the study of the optical properties of biological tissues

    NASA Astrophysics Data System (ADS)

    Yip, Man Ho; Carvalho, M. J.

    2007-12-01

    Monte-Carlo simulations are commonly used to study complex physical processes in various fields of physics. In this paper we present a Maple program intended for Monte-Carlo simulations of photon transport in biological tissues. The program has been designed so that the input data and output display can be handled by a maplet (an easy and user-friendly graphical interface), named the MonteCarloMaplet. A thorough explanation of the programming steps and how to use the maplet is given. Results obtained with the Maple program are compared with corresponding results available in the literature. Program summaryProgram title:MonteCarloMaplet Catalogue identifier:ADZU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:3251 No. of bytes in distributed program, including test data, etc.:296 465 Distribution format: tar.gz Programming language:Maple 10 Computer: Acer Aspire 5610 (any running Maple 10) Operating system: Windows XP professional (any running Maple 10) Classification: 3.1, 5 Nature of problem: Simulate the transport of radiation in biological tissues. Solution method: The Maple program follows the steps of the C program of L. Wang et al. [L. Wang, S.L. Jacques, L. Zheng, Computer Methods and Programs in Biomedicine 47 (1995) 131-146]; The Maple library routine for random number generation is used [Maple 10 User Manual c Maplesoft, a division of Waterloo Maple Inc., 2005]. Restrictions: Running time increases rapidly with the number of photons used in the simulation. Unusual features: A maplet (graphical user interface) has been programmed for data input and output. Note that the Monte-Carlo simulation was programmed with Maple 10. If attempting to run the simulation with an earlier version of Maple

  13. Fine structure and optical properties of biological polarizers in crustaceans and cephalopods

    NASA Astrophysics Data System (ADS)

    Chiou, Tsyr-Huei; Caldwell, Roy L.; Hanlon, Roger T.; Cronin, Thomas W.

    2008-04-01

    The lighting of the underwater environment is constantly changing due to attenuation by water, scattering by suspended particles, as well as the refraction and reflection caused by the surface waves. These factors pose a great challenge for marine animals which communicate through visual signals, especially those based on color. To escape this problem, certain cephalopod mollusks and stomatopod crustaceans utilize the polarization properties of light. While the mechanisms behind the polarization vision of these two animal groups are similar, several distinctive types of polarizers (i.e. the structure producing the signal) have been found in these animals. To gain a better knowledge of how these polarizers function, we studied the relationships between fine structures and optical properties of four types of polarizers found in cephalopods and stomatopods. Although all the polarizers share a somewhat similar spectral range, around 450- 550 nm, the reflectance properties of the signals and the mechanisms used to produce them have dramatic differences. In cephalopods, stack-plates polarizers produce the polarization patterns found on the arms and around their eyes. In stomatopods, we have found one type of beam-splitting polarizer based on photonic structures and two absorptive polarizer types based on dichroic molecules. These stomatopod polarizers may be found on various appendages, and on the cuticle covering dorsal or lateral sides of the animal. Since the efficiencies of all these polarizer types are somewhat sensitive to the change of illumination and viewing angle, how these animals compensate with different behaviors or fine structural features of the polarizer also varies.

  14. Chitosan as a Biomaterial: Influence of Degree of Deacetylation on Its Physiochemical, Material and Biological Properties

    PubMed Central

    Foster, Leslie John Ray; Ho, Sonia; Hook, James; Basuki, Monica; Marçal, Helder

    2015-01-01

    Chitosan is a biomaterial with a range of current and potential biomedical applications. Manipulation of chitosan degree of deacetylation (DDA) to achieve specific properties appears feasible, but studies investigating its influence on properties are often contradictory. With a view to the potential of chitosan in the regeneration of nerve tissue, the influence of DDA on the growth and health of olfactory ensheathing cells (OECs) was investigated. There was a linear increase in OEC proliferation as the DDA increased from 72 to 85%. This correlated with linear increases in average surface roughness (0.62 to 0.78 μm) and crystallinity (4.3 to 10.1%) of the chitosan films. Mitochondrial activity and membrane integrity of OECs was significantly different for OECs cultivated on chitosan with DDAs below 75%, while those on films with DDAs up to 85% were similar to cells in asynchronous growth. Apoptotic indices and cell cycle analysis also suggested that chitosan films with DDAs below 75% were cytocompatible but induced cellular stress, while OECs grown on films fabricated from chitosan with DDAs above 75% showed no significant differences compared to those in asynchronous growth. Tensile strength and elongation to break varied with DDA from 32.3 to 45.3 MPa and 3.6 to 7.1% respectively. DDA had no significant influence on abiotic and biotic degradation profiles of the chitosan films which showed approximately 8 and 20% weight loss respectively. Finally, perceived patterns in property changes are subject to change based on potential variations in DDA analysis. NMR examination of the chitosan samples here revealed significant differences depending upon which peaks were selected for integration; 6 to 13% in DDA values within individual samples. Furthermore, differences between DDA values determined here and those reported by the commercial suppliers were significant and this may also be a source of concern when selecting commercial chitosans for biomaterial research. PMID

  15. Some properties and possible biological role of peptidase inhibitors from the entomopathogenic fungus Tolypocladium cylindrosporum.

    PubMed

    Popova, V V; Dunaevsky, Y E; Domash, V I; Semenova, T A; Beliakova, G A; Belozersky, M A

    2015-10-01

    The activities of secreted and mycelial inhibitors of proteolytic enzymes from fungi of the order Hypocreales have been investigated. Inhibitors of bromelain, papain, and trypsin of low molecular mass (about 1 kDa) and a subtilisin proteinaceous inhibitor with molecular mass of 45 kDa were revealed in the culture liquid of the fungus Tolypocladium cylindrosporum. The subtilisin inhibitor from T. cylindrosporum has antibiotic properties, significantly decreased the activity of purified bacterial enzymes, and prevented the growth of the bacterium Pseudomonas sp. Data suggesting the existence in fungi of the Hypocreales order of two pools of peptidase inhibitors have been obtained. PMID:26210235

  16. Influence of Space-Flight Factors on the Properties of Microorganisms, Producers of Biologically Active Substances

    NASA Astrophysics Data System (ADS)

    Krasheninnikova, T. K.; Kanaeva, E. N.; Ukraintsev, A. D.; Smolyanaya, G. L.; Kuznetsov, N. V.; Panasyuk, M. I.; Shcherbakov, G. Ya.

    2001-07-01

    The following substances were isolated under the influence of space-flight factors in cosmic experiments aboard the Mirorbital station: an MIB-90 monoisolant, which is distinguished by its morphological and biochemical properties and enhanced productivity, was isolated from the Bacillus thuringiensis ssp. Kurstaki var. Z-52culture, which is a producer of the plant protection agent Lepidocide; and MIA-74 and MIP-89 monoisolants, which are highly active toward heavy petroleum fractions (C23 C33), were isolated from the Arthrobacter OC-1culture, which is a producer of biodegradants for petroleum.

  17. Biological and biochemical properties of two Xenopus laevis N-acetylgalactosaminyltransferases with contrasting roles in embryogenesis

    PubMed Central

    Voglmeir, Josef; Laurent, Nicolas; Flitsch, Sabine L.; Oelgeschläger, Michael; Wilson, Iain B.H.

    2015-01-01

    The biosynthesis of mucin-type O-linked glycans in animals is initiated by members of the large family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts), which play important roles in embryogenesis, organogenesis, adult tissue homeostasis and carcinogenesis. Until now, the mammalian forms of these enzymes have been the best characterized. However, two N-acetylgalactosaminyltransferases (xGalNAc-T6 and xGalNAc-T16) from the African clawed frog (Xenopus laevis), which are most homologous to those encoded by the human GALNT6 and GALNT16 (GALNTL1) genes, were shown to have contrasting roles in TGF-β/BMP signaling in embryogenesis. In this study we have examined these two enzymes further and show differences in their in vivo function during X. laevis embyrogenesis as evidenced by in situ hybridization and overexpression experiments. In terms of enzymatic activity, both enzymes were found to be active towards the EA2 peptide, but display differential activity towards a peptide based on the sequence of ActR-IIB, a receptor relevant to TGF-β/BMP signaling. In summary, these data demonstrate that these two enzymes from different branches of the N-acetylgalactosaminyltransferase do not only display differential substrate specificities, but also specific and distinct expression pattern and biological activities in vivo. PMID:25447273

  18. Composting of the solid fraction of digestate derived from pig slurry: Biological processes and compost properties.

    PubMed

    Tambone, Fulvia; Terruzzi, Laura; Scaglia, Barbara; Adani, Fabrizio

    2015-01-01

    The aim of this paper was to assess the characteristics of the solid fractions (SF) obtained by mechanical separation of digestate, their compostability and compost quality. To do so, the SF of digestates obtained from anaerobic digestion of pig slurry, energy crops and agro-industrial residues were sampled in five plants located in Northern Italy. Results obtained indicated that anaerobic digestion by itself promoted the high biological stability of biomasses with a Potential Dynamic Respiration Index (PDRI) close to 1000 mgO2 kg V S(-1)h(-1). Subsequent composting of digestates, with an added bulking agent, did not give remarkably different results, and led only to a slight modification of the characteristics of the initial non-composted mixtures; the composts obtained fully respected the legal limits for high quality compost. Chemical studies of organic matter composition of the biomasses by using CP MAS (13)C NMR, indicated that the compost was composed of a high relative content of O-alkyl-C (71.47% of total C) (cellulose and hemicelluloses) and a low alkyl-C (12.42%) (i.e. volatile fatty acids, steroid-like molecules, aliphatic biopolymers and proteins). PMID:25458767

  19. Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles.

    PubMed

    Novak, Maria S; Büchel, Gabriel E; Keppler, Bernhard K; Jakupec, Michael A

    2016-06-01

    Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed. PMID:26961253

  20. New insights into the biological activity and secretion properties of a polypeptide derived from tilapia somatotropin.

    PubMed

    Acosta, Jannel; Carpio, Yamila; Morales, Reynold; Aguila, Julio César; Acanda, Yosvani; Herrera, Fidel; Estrada, Mario P

    2010-08-01

    In a previous study, we unexpectedly found that tilapia growth hormone (tiGH) secreted to the culture media by transformed cells of the yeast Pichia pastoris lacks 46 amino acids from the C-terminal end. In the present study, we cloned the exact fragment that code for this truncated variant and demonstrated its growth promoting activity in goldfish when it's administered by immersion bath. Furthermore, a better characterization of this polypeptide was performed. Administration of the polypeptide derived from tiGH increased superoxide anion production and has a mitogenic effect on peripheral blood leukocytes. This molecule binds to liver membranes proteins in vitro in a saturable manner. Beside, we cloned and expressed tiGH and its truncated variant in mammalian cells using the signal peptide of this hormone and we observed that the secretion was drastically reduced in the truncated tiGH as compared to the intact molecule. Truncated tilapia growth hormone lacking the helix 4 and two disulfide loops is still a bioactive hormone, suggesting that the disulfide bonds and the helix 4 are not essential for the biological activities examined in this work. However, the growth hormone C-terminal portion seems to be essential for this hormone to be secreted by cultured cells in vitro. PMID:20382254

  1. Immunological and biological properties of iodoinsulin labeled with one or less atoms of iodine per molecule

    PubMed Central

    Arquilla, Edward R.; Ooms, Henri; Mercola, Karen

    1968-01-01

    Experiments were designed to compare the distribution of free and antibody-bound unlabeled insulin to the distribution of free and antibody-bound insulin-125I. The insulin antibody was incorporated in a specific immune precipitate similar to the one used by Hales and Randle for the radioimmune assay of insulin. Insulin which was not bound by the specific immune precipitate was measured by the immune hemolysis inhibition assay. This report contains evidence that the addition of the unlabeled insulin in the radioimmune assay results in relatively more insulin-125I which remains free and less bound by antibodies than is the case with the unlabeled insulin. Methods are described for the separation of an electrophoretically homogeneous iodoinsulin from samples of crude iodoinsulin with average incorporations of less than 0.2 atoms iodine per molecule. These purified iodoinsulin fractions have a markedly attenuated biological activity. Evidence is presented which supports the postulate that only a portion of the antibodies in guinea pig insulin antiserum are capable of effectively binding with purified iodoinsulin. Images PMID:5637137

  2. Influence of taro (Colocasia esculenta L. Shott) growth conditions on the phenolic composition and biological properties.

    PubMed

    Gonçalves, Rui F; Silva, Artur M S; Silva, Ana Margarida; Valentão, Patrícia; Ferreres, Federico; Gil-Izquierdo, Angel; Silva, João B; Santos, Delfim; Andrade, Paula B

    2013-12-15

    Colocasia esculenta (L.) Shott, commonly known as taro, is an essential food for millions of people. The leaves are consumed in sauces, purees, stews, and soups, being also used in wound healing treatment. Nowadays, the consumers' demand for bioactive compounds from the diet led to the development of new agricultural strategies for the production of health-promoting constituents in vegetables. In this work, two strategies (variety choice and irrigation conditions) were considered in the cultivation of C. esculenta. The effect on the phenolic composition of the leaves was evaluated. Furthermore, a correlation between the biological activity of the different varieties and their chemical composition was established. Qualitative and quantitative differences in the phenolic composition were observed between varieties; furthermore, the irrigation conditions also influenced the composition. C. esculenta varieties were able to scavenge several oxidant species and to inhibit hyaluronidase, but data suggest that metabolites other than phenolics are involved. The results show that cultivation strategies can effectively modulate the accumulation of these types of bioactive compounds. Furthermore C. esculenta wound healing potential can be attributed, at least in part, to the protection of the wound site against oxidative/nitrosative damage and prevention of hyaluronic acid degradation. PMID:23993510

  3. Biological properties of different type carbon particles in vitro study on primary culture of endothelial cells.

    PubMed

    Czerniak-Reczulska, M; Niedzielski, P; Balcerczyk, A; Bartosz, G; Karowicz-Bilińska, A; Mitura, K

    2010-02-01

    Carbon powders have extended surface of carbon layers, which is of significant biomedical importance since the powders are employed to cover implants material. Carbon Powder Particles are produced by different methods: by a detonation method, by RF PACVD (Radio Frequency Plasma Activated Chemical Vapour Deposition) or MW/RF PCVD (Microwave/Radio Frequency Plasma Activated Chemical Vapour Deposition) and others. Our previous data showed that Carbon Powder Particles may act as antioxidant and/or anti-inflammatory factor. However the mechanism of such behavior has been not fully understood. The aim of the work was tested influence carbon powders manufactured by Radio Frequency Plasma Activated Chemical Vapour Deposition RFPACVD method and detonation method on selected parameters of human endothelial cells, which play a crucial role in the regulation of the circulation and vascular wall homeostasis. Graphite powder was used as a control substance. Endothelial cells are actively involved in a wide variety of processes e.g., inflammatory responses to a different type of stimuli (ILs, TNF-alpha) or regulating vasomotor tone via production of vasorelaxants and vasocontrictors. Biological activation is dependent on the type and quantity of chemical bonds on the surface of the powders. The effect of powders on the proliferation of HUVECs (Human Umbilical Vein Endothelial Cells) was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction assay. We found decreased cell proliferation after 72 h treatment with graphite as well as Carbon Powder Particles. PMID:20352757

  4. [B17-D-leucine]insulin and [B17-norleucine]insulin: synthesis and biological properties.

    PubMed

    Knorr, R; Danho, W; Büllesbach, E E; Gattner, H G; Zahn, H; King, G L; Kahn, C R

    1983-11-01

    The chemical synthesis of two porcine insulin analogues is described. Leucine in position B17 of the native molecule was substituted by its D-enantiomer and by L-norleucine, respectively. Both B-chain derivatives were synthesized by fragment condensation and purified as di-S-sulphonates by gel filtration followed by ion exchange chromatography on SP-Sephadex at pH3. Combination with native sulphhydryl A-chain yielded [DLeuB17]insulin and [NleB17]insulin. Both insulin analogues were isolated by gel filtration followed by ion exchange chromatography on CM-cellulose at pH 4.0. Biological activities of the analogues were determined relative to native pork insulin: 1) glucose oxidation in rat epididymal adipocytes was 6% for [DLeuB17]insulin and 16% for [NleB17]insulin, 2) receptor-binding affinity tested with cultured human fibroblasts and with rat adipocytes was 3% for [DLeuB17]insulin and 26% for [NleB17]insulin, and 3) thymidine incorporation into DNA of human fibroblasts was 35% for [DLeuB17]insulin and 100% for [NleB17]insulin. PMID:6363268

  5. Therapeutic Uses and Pharmacological Properties of Garlic, Shallot, and Their Biologically Active Compounds

    PubMed Central

    Mikaili, Peyman; Maadirad, Surush; Moloudizargari, Milad; Aghajanshakeri, Shahin; Sarahroodi, Shadi

    2013-01-01

    Objective(s): Garlic (Allium sativum L. family Liliaceae) is well known in Iran and its leaves, flowers, and cloves have been used in traditional medicine for a long time. Research in recent decades has shown widespread pharmacological effects of A. sativum and its organosulfur compounds especially Allicin. Studies carried out on the chemical composition of the plant show that the most important constituents of this plant are organosulfur compounds such as allicin, diallyl disulphide, S-allylcysteine, and diallyl trisulfide. Allicin represents one of the most studied among these naturally occurring compounds. In addition to A. sativum, these compounds are also present in A. hirtifolium (shallot) and have been used to treat various diseases. This article reviews the pharmacological effects and traditional uses of A. sativum, A. hirtifolium, and their active constituents to show whether or not they can be further used as potential natural sources for the development of novel drugs. Materials and Methods: For this purpose, the authors went through a vast number of sources and articles and all needed data was gathered. The findings were reviewed and classified on the basis of relevance to the topic and a summary of all effects were reported as tables. Conclusion: Garlic and shallots are safe and rich sources of biologically active compounds with low toxicity. Further studies are needed to confirm the safety and quality of the plants to be used by clinicians as therapeutic agents. PMID:24379960

  6. [Biologic and molecular genetic properties of a transplantable human primary gastric cancer in nude mice].

    PubMed

    Chen, S S

    1989-05-01

    A human primary gastric cancer tissue (adenocarcinoma II-III) was transplanted into nude mice (SWISS/DF. nu/nu). It has been transferred for 8 generations at 56 sites in 28 nude mice with transplantable rate of 100%. The transplanted tumor is designated as transplantable human primary gastric cancer-1 in nude mice (THPGC-1). The growth of THPGC-1 is rather rapid and the size of transplanted tumor reaches 1 cm2, 4-5 weeks after transfer. The morphology and histochemistry of the original tumor were retained well in the initial and serial transplanted tumors. THPGC-1 could secret carcinoembryonic antigen (CEA). After intravenous or intraperitoneal injection of 131I-antiCEA monoclonal antibody into the THPGC-1 bearing nude mice, the radiolabeled antibody was concentrated and localized in the tumor as shown by gamma-camera analysis. Similar pattern of lactate dehydrogenase isoenzyme was observed both in primary gastric cancer tissue and THPGC-1 tissue. Chromosomal examination revealed that THPGC-1 was human aneuploid ones. Southern blot analysis showed that the pattern of repetitive DNA bands and the structures of 28s, rDNA, c-H-ras and c-myc genes in THPGC-1 were identical to the original primary gastric cancer DNA. The results suggest that THPGC-1 be a reliable model for the research of the molecular biology of cancer cells and experimental gastric cancer diagnosis and treatment. PMID:2693024

  7. Properties of biological and biochemical effects of the Iranian saw-scaled viper (Echis carinatus) venom.

    PubMed

    Babaie, M; Salmanizadeh, H; Zolfagharian, H; Alizadeh, H

    2014-01-01

    The venom of Echis carinatus is rich in proteins and peptides effective on the hemostatic system. This venom is contains metalloproteinase which convert prothrombin to meizothrombin. The prothrombin activator which leads to the formation of small blood clots inside the blood vessels throughout the body. To understand the mechanism of the effects of Iranian Echis carinatus venom, the effects of E. carinatus on human and Wistar rat plasma, plasma proteins (prothrombin and fibrinogen) and blood coagulation were studied. Proteolytic activity of the crude venom on blood coagulation factors such as prothrombin, partial thromboplastin and fibrinogen times were studied. In the present study the PT test for human plasma was reduced from 13.4 s (±0.59) to 8.6 s (±0.64) when human plasma was treated with crude venom (concentration of venom was 1 mg/ml) and for rat plasma PT was reduced from 14.5 s (±0.47) to 8 s (±0.49). Some possible biological and biochemical effects of IEc crude venom were investigated. The blood coagulation in human and in rat were investigated in vivo and in-vitro. In this paper, we show that the procoagulant action of Echis carinatus venom is due in part to a protein component that activates prothrombin and the procoagulant activity on human and rat plasma was evaluated (Tab. 2, Fig. 2, Ref. 31). PMID:25077367

  8. The Investigation of Property of Radiation and Absorbed of Infrared Lights of the Biological Tissues

    NASA Astrophysics Data System (ADS)

    Pang, Xiao-Feng; Deng, Bo; Xiao, He-Lan; Cai, Guo-Ping

    2010-04-01

    The properties of absorption of infrared light for collagen, hemoglobin, bivine serum albumen (BSA) protein molecules with α- helix structure and water in the living systems as well as the infrared transmission spectra for person’s skins and finger hands of human body in the region of 400-4000 cm-1 (i.e., wavelengths of 2-20 μm) have been collected and determined by using a Nicolet Nexus 670 FT-IR Spectrometer, a Perkin Elmer GX FT-IR spectrometer, an OMA (optical multichannel analysis) and an infrared probe systems, respectively. The experimental results obtained show that the protein molecules and water can all absorb the infrared lights in the ranges of 600-1900 cm-1 and 2900-3900 cm-l, but their properties of absorption are somewhat different due to distinctions of their structure and conformation and molecular weight. We know from the transmission spectra of person’s finger hands and skin that the infrared lights with wavelengths of 2 μm-7 μm can not only transmit over the person’s skin and finger hands, but also be absorbed by the above proteins and water in the living systems. Thus, we can conclude from this study that the human beings and animals can absorb the infrared lights with wavelengths of 2 μm-7 μm.

  9. Physicochemical and biological properties of a novel injectable polyurethane system for root canal filling

    PubMed Central

    Wang, Jian; Zuo, Yi; Zhao, Minghui; Jiang, Jiaxing; Man, Yi; Wu, Jun; Hu, Yunjiu; Liu, Changlei; Li, Yubao; Li, Jidong

    2015-01-01

    A root canal sealer with antibacterial activity can be efficacious in preventing reinfection that results from residual microorganisms and/or the leakage of microorganisms. In the present study, a series of injectable, self-curing polyurethane (PU)-based antibacterial sealers with different concentrations of silver phosphate (Ag3PO4) were fabricated. Subsequently, their physicochemical properties, antibacterial abilities, and preliminary cytocompatibilities were evaluated. The results indicated that the fabricated PU-based sealers can achieve a high conversion rate in a short amount of time. More than 95% of the isocyanate group of PU sealers with 3 wt% (PU3) and 5 wt% (PU5) concentrations of Ag3PO4 were included in the curing reaction after 7 hours. With the exception of those for film thickness for PU5, the results of setting time, film thickness, and solubility were able to meet the requirements of the International Organization for Standardization. The antibacterial tests showed that PU3 and PU5 exhibit stronger antimicrobial effects than that achieved with 1 wt% Ag3PO4 (PU1) and AH Plus (positive control) against Streptococcus mutans. The cytocompatibility evaluation revealed that the PU1 and PU3 sealers possess good cytocompatibility and low cytotoxicity. These results demonstrate that the PU3 sealer offers good physicochemical and antimicrobial properties along with cytocompatibility, which may hold great application potential in the field of root canal fillings. PMID:25653518

  10. Mechanical, In Vitro Antimicrobial and Biological Properties of Plasma Sprayed Silver-Doped Hydroxyapatite Coating

    PubMed Central

    Roy, Mangal; Fielding, Gary A.; Beyenal, Haluk; Bandyopadhyay, Amit; Bose, Susmita

    2012-01-01

    Implant related infection is one of the key concerns in total joint hip arthroplasties. In order to reduce bacterial adhesion, silver (Ag) / silver oxide (Ag2O) doping was used in plasma sprayed hydroxyapatite (HA) coating on titanium substrate. HA powder was doped with 2.0, 4.0 and 6.0 wt% Ag, heat treated at 800 °C and used for plasma spray coating using a 30 kW plasma spray system, equipped with supersonic nozzle. Application of supersonic plasma nozzle significantly reduced phase decomposition and amorphous phase formation in the HA coatings as evident by X-ray diffraction (XRD) study and Fourier transformed infrared spectroscopic (FTIR) analysis. Adhesive bond strength of more than 15 MPa ensured the mechanical integrity of the coatings. Resistance against bacterial adhesion of the coatings was determined by challenging them against Pseudomonas Aeruginosa (PAO1). Live/Dead staining of the adherent bacteria on the coating surfaces indicated a significant reduction in bacterial adhesion due to the presence of Ag. In vitro cell-material interactions and alkaline phosphatase (ALP) protein expressions were evaluated by culturing human fetal osteoblast cells (hFOB). Present results suggest that the plasma sprayed HA coatings doped with an optimum amount of Ag can have excellent antimicrobial property without altering mechanical property of the Ag doped HA coatings. PMID:22313742

  11. Physicochemical and biological properties of a novel injectable polyurethane system for root canal filling.

    PubMed

    Wang, Jian; Zuo, Yi; Zhao, Minghui; Jiang, Jiaxing; Man, Yi; Wu, Jun; Hu, Yunjiu; Liu, Changlei; Li, Yubao; Li, Jidong

    2015-01-01

    A root canal sealer with antibacterial activity can be efficacious in preventing reinfection that results from residual microorganisms and/or the leakage of microorganisms. In the present study, a series of injectable, self-curing polyurethane (PU)-based antibacterial sealers with different concentrations of silver phosphate (Ag3PO4) were fabricated. Subsequently, their physicochemical properties, antibacterial abilities, and preliminary cytocompatibilities were evaluated. The results indicated that the fabricated PU-based sealers can achieve a high conversion rate in a short amount of time. More than 95% of the isocyanate group of PU sealers with 3 wt% (PU3) and 5 wt% (PU5) concentrations of Ag3PO4 were included in the curing reaction after 7 hours. With the exception of those for film thickness for PU5, the results of setting time, film thickness, and solubility were able to meet the requirements of the International Organization for Standardization. The antibacterial tests showed that PU3 and PU5 exhibit stronger antimicrobial effects than that achieved with 1 wt% Ag3PO4 (PU1) and AH Plus (positive control) against Streptococcus mutans. The cytocompatibility evaluation revealed that the PU1 and PU3 sealers possess good cytocompatibility and low cytotoxicity. These results demonstrate that the PU3 sealer offers good physicochemical and antimicrobial properties along with cytocompatibility, which may hold great application potential in the field of root canal fillings. PMID:25653518

  12. Water-soluble polysaccharides from agro-industrial by-products: functional and biological properties.

    PubMed

    Sila, Assaâd; Bayar, Nadia; Ghazala, Imen; Bougatef, Ali; Ellouz-Ghorbel, Raoudha; Ellouz-Chaabouni, Semia

    2014-08-01

    Water-soluble polysaccharides were isolated from almond (AWSP) and pistachio (PWSP) juice processing by-products. Their chemical and physical characteristics were determined using NMR and Infrared spectroscopic analysis. The complexities of the spectra reflected the heterogeneity of these polysaccharides. The ACE inhibitory activities (IC50 AWSP=2.81mgmL(-1) and IC50 PWSP=2.59mgmL(-1)) and antioxidant properties of AWSP and PWSP were investigated based on the DPPH radical-scavenging capacity assay (IC50 AWSP=2.87mgmL(-1) and IC50 PWSP=1.61mgmL(-1)). Reducing power, β-carotene bleaching inhibition (IC50AWSP=4.46mgmL(-1) and IC50 PWSP=3.39mgmL(-1)), and ferrous chelating assays (IC50 AWSP=0.22mgmL(-1) and IC50 PWSP=0.19mgmL(-1)) were also performed. The findings revealed that water-soluble polysaccharides exhibited antioxidant and antihypertensive activities. AWSP and PWSP showed excellent interfacial concentration-dependent properties. Overall, the results suggested that both AWSP and PWSP are promising sources of natural antioxidants and ACE inhibitory agents and could, therefore, be used as alternative additives in food, pharmaceutical and cosmetic preparations. PMID:24875325

  13. Mechanical, in vitro antimicrobial, and biological properties of plasma-sprayed silver-doped hydroxyapatite coating.

    PubMed

    Roy, Mangal; Fielding, Gary A; Beyenal, Haluk; Bandyopadhyay, Amit; Bose, Susmita

    2012-03-01

    Implant-related infection is one of the key concerns in total joint hip arthroplasties. To reduce bacterial adhesion, we used silver (Ag)/silver oxide (Ag(2)O) doping in plasma sprayed hydroxyapatite (HA) coating on titanium substrate. HA powder was doped with 2.0, 4.0, and 6.0 wt % Ag, heat-treated at 800 °C and used for plasma spray coating using a 30 kW plasma spray system, equipped with supersonic nozzle. Application of supersonic plasma nozzle significantly reduced phase decomposition and amorphous phase formation in the HA coatings as evident by X-ray diffraction (XRD) study and Fourier transformed infrared spectroscopic (FTIR) analysis. Adhesive bond strength of more than 15 MPa ensured the mechanical integrity of the coatings. Resistance against bacterial adhesion of the coatings was determined by challenging them against Pseudomonas aeruginosa (PAO1). Live/dead staining of the adherent bacteria on the coating surfaces indicated a significant reduction in bacterial adhesion due to the presence of Ag. In vitro cell-material interactions and alkaline phosphatase (ALP) protein expressions were evaluated by culturing human fetal osteoblast cells (hFOB). Our results suggest that the plasma-sprayed HA coatings doped with an optimum amount of Ag can have excellent antimicrobial property without altering mechanical property of the Ag-doped HA coatings. PMID:22313742

  14. Divalent Amino-Acid-Based Amphiphilic Antioxidants: Synthesis, Self-Assembling Properties, and Biological Evaluation.

    PubMed

    Rosselin, Marie; Meyer, Grégory; Guillet, Pierre; Cheviet, Thomas; Walther, Guillaume; Meister, Annette; Hadjipavlou-Litina, Dimitra; Durand, Grégory

    2016-03-16

    We report herein the synthesis of a divalent amphiphilic carrier onto which α-phenyl-N-tert-butyl nitrone (PBN) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) antioxidants were grafted to give the divalent derivative called FATxPBN. The divalent carrier consists of two lysine amino acids as a scaffold upon which the antioxidant moieties are grafted, a perfluorinated chain that supplies hydrophobicity, and a sugar-based polar headgroup that ensures water solubility. For the sake of comparison, a divalent PBN derivative called FADiPBN was also synthesized. The self-aggregation properties of FATxPBN and FADiPBN were studied by means of surface tension, dynamic light scattering, and transmission electron microscopy methods, and showed they form small micelles (i.e., 12 and 6 nm diameter, respectively) at submillimolar concentrations (i.e., 0.01 and 0.05 mM, respectively), in agreement with partition coefficient values. The superior antioxidant properties of FATxPBN over FADiPBN and the parent compounds PBN and Trolox were demonstrated using in vitro ABTS(•+) reduction (98%) and soybean lipoxygenase inhibition (94%) assays. Finally, FATxPBN was found to significantly inhibit hyperglycemia-induced toxicity on an ex-vivo rat model, demonstrating its potency as a bioactive antioxidant against oxidative stress-induced damage. PMID:26850367

  15. Unusual luminescent properties of water: the major component of biological fluids

    NASA Astrophysics Data System (ADS)

    Lobyshev, Valentin I.; Shihlinskaya, Rogneda E.

    1997-05-01

    It was found that distilled water possesses weak luminescence in the near UV and visible regions of the spectrum. The excitation spectrum is complex and has two main maxima, at 270 and 310 nm. The corresponding emission spectra apart from a narrow lines due to Raman scattering are represented by wide lines at 360 and 410 nm and are determined by the inherent properties of water. The intensity of luminescence depends on the time of holding of a sample in a closed vessel and the addition of a small amount of both luminescent and non-luminescent dipeptides. The observed phenomena can not be reduced to the luminescence of admixtures in water, but is a result of unique properties of water, its structure and polymorphism. The effect of water 'hardening' occurring upon rapid cooling of a hot sample to a room temperature, in contrast to slow cooling, is discovered. It is attributed to the formation of a new steady state of an aqueous structure, indicating by very intensive luminescence band at 5450 nm. Relative intensities of the described bands of emission are greatly sensitive to weak fields of electromagnetic nature. The phenomena observed lead to the conclusion that water and aqueous solutions should be regarded as a continuous polymorphous containing defects structures which are in general non-equilibrium self-organizing systems.

  16. Superior in vitro biological response and mechanical properties of an implantable nanostructured biomaterial: Nanohydroxyapatite-silicone rubber composite.

    PubMed

    Thein-Han, W W; Shah, J; Misra, R D K

    2009-09-01

    A potential approach to achieving the objective of favorably modulating the biological response of implantable biopolymers combined with good mechanical properties is to consider compounding the biopolymer with a bioactive nanocrystalline ceramic biomimetic material with high surface area. The processing of silicone rubber (SR)-nanohydroxyapatite (nHA) composite involved uniform dispersion of nHA via shear mixing and ultrasonication, followed by compounding at sub-ambient temperature, and high-pressure solidification when the final curing reaction occurs. The high-pressure solidification approach enabled the elastomer to retain the high elongation of SR even in the presence of the reinforcement material, nHA. The biological response of the nanostructured composite in terms of initial cell attachment, cell viability and proliferation was consistently greater on SR-5wt.% nHA composite surface compared to pure SR. Furthermore, in the nanocomposite, cell spreading, morphology and density were distinctly different from that of pure SR. Pre-osteoblasts grown on SR-nHA were well spread, flat, large in size with a rough cell surface, and appeared as a group. In contrast, these features were less pronounced in SR (e.g. smooth cell surface, not well spread). Interestingly, an immunofluorescence study illustrated distinct fibronectin expression level, and stronger vinculin focal adhesion contacts associated with abundant actin stress fibers in pre-osteoblasts grown on the nanocomposite compared to SR, implying enhanced cell-substrate interaction. This finding was consistent with the total protein content and SDS-PAGE analysis. The study leads us to believe that further increase in nHA content in the SR matrix beyond 5wt.% will encourage even greater cellular response. The integration of cellular and molecular biology with materials science and engineering described herein provides a direction for the development of a new generation of nanostructured materials. PMID:19435616

  17. Method for Finding Metabolic Properties Based on the General Growth Law. Liver Examples. A General Framework for Biological Modeling

    PubMed Central

    Shestopaloff, Yuri K.

    2014-01-01

    We propose a method for finding metabolic parameters of cells, organs and whole organisms, which is based on the earlier discovered general growth law. Based on the obtained results and analysis of available biological models, we propose a general framework for modeling biological phenomena and discuss how it can be used in Virtual Liver Network project. The foundational idea of the study is that growth of cells, organs, systems and whole organisms, besides biomolecular machinery, is influenced by biophysical mechanisms acting at different scale levels. In particular, the general growth law uniquely defines distribution of nutritional resources between maintenance needs and biomass synthesis at each phase of growth and at each scale level. We exemplify the approach considering metabolic properties of growing human and dog livers and liver transplants. A procedure for verification of obtained results has been introduced too. We found that two examined dogs have high metabolic rates consuming about 0.62 and 1 gram of nutrients per cubic centimeter of liver per day, and verified this using the proposed verification procedure. We also evaluated consumption rate of nutrients in human livers, determining it to be about 0.088 gram of nutrients per cubic centimeter of liver per day for males, and about 0.098 for females. This noticeable difference can be explained by evolutionary development, which required females to have greater liver processing capacity to support pregnancy. We also found how much nutrients go to biomass synthesis and maintenance at each phase of liver and liver transplant growth. Obtained results demonstrate that the proposed approach can be used for finding metabolic characteristics of cells, organs, and whole organisms, which can further serve as important inputs and constraints for many applications in biology (such as protein expression), biotechnology (synthesis of substances), and medicine. PMID:24940740

  18. Identification of a family of fatty acid-speciated Sonic Hedgehog proteins, whose members display differential biological properties

    PubMed Central

    Houel, Stephane; Rodgriguez-Blanco, Jezabel; Singh, Samer; Schilling, Neal; J.Capobianco, Anthony; Ahn, Natalie G.; Robbins, David J.

    2015-01-01

    SUMMARY Hedgehog (HH) proteins are proteolytically processed into a biologically active form, which is covalently modified by cholesterol and palmitate. However, most studies of HH biogenesis have characterized protein from cells in which HH is over-expressed. We purified Sonic Hedgehog (SHH) from cells expressing physiologically relevant levels, and showed that it was more potent than SHH isolated from over-expressing cells. Furthermore, the SHH in our preparations were modified with a diverse spectrum of fatty acids on their amino-termini, and this spectrum of fatty acids varied dramatically depending on the growth conditions of the cells. The fatty acid composition of SHH affected its trafficking to lipid rafts, as well as its potency. Our results suggest that HH proteins exist as a family of diverse lipid-speciated proteins, which might be altered in different physiological and pathological contexts to regulate distinct properties of HH proteins. PMID:25732819

  19. Conformational, spectroscopic and nonlinear optical properties of biologically active N,N-dimethyltryptamine molecule: a theoretical study.

    PubMed

    Öner, Nazmiye; Tamer, Ömer; Avcı, Davut; Atalay, Yusuf

    2014-12-10

    The effective psychoactive properties of N,N-dimethyltryptamine (DMT) known as the near-death molecule have encouraged the imagination of many research disciplines for several decades. Although there is no theoretical study, a number of paper composed by experimental techniques have been reported for DMT molecule. In this study, the molecular modeling of DMT was carried out using B3LYP and HSEh1PBE levels of density functional theory (DFT). Our calculations showed that the energy gap between HOMO and LUMO is low, demonstrating that DMT is a biologically active molecule. Large hyperconjugation interaction energies imply that molecular charge transfer occurs in DMT. Moreover, NLO analysis indicates that DMT can be used an effective NLO material. PMID:24983923

  20. [Biological and physico-chemical properties of Yersinia pseudotuberculosis bacterial culture having the fra-operon Yersinia pestis].

    PubMed

    Byvalov, A A; Gavrilov, K E; Krupin, V V; Chebotarev, E V; Zheludkova, E V; Drubkov, V I; Smirnov, A E; Mal'kov, V N; Dupiasheva, T Iu; Pechenkin, D V; Bondarev, V P

    2008-01-01

    The biological and physico-chemical properties of cultures of two isogenous recombinant variants of Yersinia pseudotuberculosis were studied. The cell genomes of the cultures are distinguished from one another only by the presence or by the absence of the fra-operon, which is a determined attribute of the plague microbe capsule-forming process. The expression of the attribute is amplified by rising the microbial biomass cultivation temperature and stimulates the decrease in the viability of the bacteria and adaptation potential in vitro. In the warm-blooded owner organism the microbes of the capsule-forming recombinant variant are characterized by the greater residual pathogenicity and immunogenic ability to the experimental plague of the laboratory animals as compared to the reference-variant cells. These specific features could be explained by more expressed colonizing ability of the capsule-forming microbes provided by owner cells' stability to the phagocyte process. PMID:18368776

  1. Conformational, spectroscopic and nonlinear optical properties of biologically active N,N-dimethyltryptamine molecule: A theoretical study

    NASA Astrophysics Data System (ADS)

    Öner, Nazmiye; Tamer, Ömer; Avcı, Davut; Atalay, Yusuf

    2014-12-01

    The effective psychoactive properties of N,N-dimethyltryptamine (DMT) known as the near-death molecule have encouraged the imagination of many research disciplines for several decades. Although there is no theoretical study, a number of paper composed by experimental techniques have been reported for DMT molecule. In this study, the molecular modeling of DMT was carried out using B3LYP and HSEh1PBE levels of density functional theory (DFT). Our calculations showed that the energy gap between HOMO and LUMO is low, demonstrating that DMT is a biologically active molecule. Large hyperconjugation interaction energies imply that molecular charge transfer occurs in DMT. Moreover, NLO analysis indicates that DMT can be used an effective NLO material.

  2. Essential oils from wild populations of Algerian Lavandula stoechas L.: composition, chemical variability, and in vitro biological properties.

    PubMed

    Benabdelkader, Tarek; Zitouni, Abdelghani; Guitton, Yann; Jullien, Frédéric; Maitre, Dany; Casabianca, Hervé; Legendre, Laurent; Kameli, Abdelkrim

    2011-05-01

    In an effort to develop local productions of aromatic and medicinal plants, a comprehensive assessment of the composition and biological activities of the essential oils (EOs) extracted from the aerial flowering parts of wild growing Lavandula stoechas L. collected from eleven different locations in northern Algeria was performed. The oils were characterized by GC-FID and GC/MS analyses, and 121 compounds were identified, accounting for 69.88-91.2% of the total oil compositions. The eleven oils greatly differed in their compositions, since only 66 compounds were common to all oils. Major EO components were fenchone (2; 11.27-37.48%), camphor (3, 1.94-21.8%), 1,8-cineole (1; 0.16-8.71%), and viridiflorol (10; 2.89-7.38%). The assessed in vitro biological properties demonstrated that the DPPH-based radical-scavenging activities and the inhibition of the β-carotene/linoleic acid-based lipid oxidation differed by an eight-fold factor between the most and the least active oils and were linked to different sets of molecules in the different EOs. The eleven EOs exhibited good antimicrobial activities against most of the 16 tested strains of bacteria, filamentous fungi, and yeasts, with minimum inhibitory concentrations (MICs) ranging from 0.16 to 11.90 mg/ml. PMID:21560242

  3. Contrasting optical properties of surface waters across the Fram Strait and its potential biological implications

    NASA Astrophysics Data System (ADS)

    Pavlov, Alexey K.; Granskog, Mats A.; Stedmon, Colin A.; Ivanov, Boris V.; Hudson, Stephen R.; Falk-Petersen, Stig

    2015-03-01

    Underwater light regime is controlled by distribution and optical properties of colored dissolved organic matter (CDOM) and particulate matter. The Fram Strait is a region where two contrasting water masses are found. Polar water in the East Greenland Current (EGC) and Atlantic water in the West Spitsbergen Current (WSC) differ with regards to temperature, salinity and optical properties. We present data on absorption properties of CDOM and particles across the Fram Strait (along 79° N), comparing Polar and Atlantic surface waters in September 2009 and 2010. CDOM absorption of Polar water in the EGC was significantly higher (more than 3-fold) compared to Atlantic water in the WSC, with values of absorption coefficient, aCDOM(350), m- 1 of 0.565 ± 0.100 (in 2009) and 0.458 ± 0.117 (in 2010), and 0.138 ± 0.036 (in 2009) and 0.153 ± 0.039 (in 2010), respectively. An opposite pattern was observed for particle absorption with higher absorption found in the eastern part of the Fram Strait. Average values of particle absorption (aP(440), m- 1) were 0.016 ± 0.013 (in 2009) and 0.014 ± 0.011 (in 2010), and 0.047 ± 0.012 (in 2009) and 0.016 ± 0.014 (in 2010), respectively for Polar and Atlantic water. Thus absorption of light in eastern part of the Fram Strait is dominated by particles - predominantly phytoplankton, and the absorption of light in the western part of the strait is dominated by CDOM, with predominantly terrigenous origin. As a result the balance between the importance of CDOM and particulates to the total absorption budget in the upper 0-10 m shifts across Fram Strait. Under water spectral irradiance profiles were generated using ECOLIGHT 5.4.1 and the results indicate that the shift in composition between dissolved and particulate material does not influence substantially the penetration of photosynthetic active radiation (PAR, 400-700 nm), but does result in notable differences in ultraviolet (UV) light penetration, with higher attenuation in the

  4. [Influence of the Composition of the Initial Mixtures on the Physicochemical and Biological Properties and Spectral Characteristics of Composts].

    PubMed

    Song, Cai-hong; Li, Ming-xiao; Wei, Zi-min; Xi, Bei-dou; Zhao, Yue; Jia, Xuan; Liu, Ya-ru; Liu, Dong-ming

    2015-08-01

    In this work, biogas residues, the remnant of the anaerobic digestion, was used for composting with livestock manure as the co-substrate. It is important for improving the soil quality in China, because the negative influence of biogas residues being utilized directly as organic fertilizer (a mainstream way of disposing biogas residues in China) on the soil could be eliminated or mitigated via composting. The composition of composting substrate has a great influence on the composting process. To explore the influence of the composition of the initial mixtures on the physicochemical properties and spectroscopic characteristics of composts, fifteen co-composting of biogas residue, pig manure and chicken manure, with different material ratios, were carried out. Physicochemical and biological indicators were determined. Meanwhile, spectroscopic methods, such as UV-Vis, synchronous fluorescence and 3D-EEM spectra were used for identifying characteristic spectral parameters companied with FRI and PARAFAC. Therefore, spectroscopic characteristics of composts were characterized. The relationship between physicochemical properties of composts and the composition of the initial mixtures was established using CCA. Similarly, that between spectroscopic characteristics of composts and the composition of the initial mixtures was also established. The results showed that: physicochemical properties of composts exhibits a significant correlation with the composition of the initial mixtures. A significant correlation between spectroscopic characteristics of composts and the composition of the initial mixtures was also observed. In the two CCA, the former four axes account for 83.9% and 97.5% of the total sample variation. The influence of enviro nmental factors on physicochemical properties of composts was in the order of pig manure amount>chicken manure amount>biogas residue amount and that on spectroscopic characteristics of composts was in the order of biogas residue amount

  5. Laser-induced damage in biological tissue: Role of complex and dynamic optical properties of the medium

    NASA Astrophysics Data System (ADS)

    Ahmed, Elharith M.

    Since its invention in the early 1960's, the laser has been used as a tool for surgical, therapeutic, and diagnostic purposes. To achieve maximum effectiveness with the greatest margin of safety it is important to understand the mechanisms of light propagation through tissue and how that light affects living cells. Lasers with novel output characteristics for medical and military applications are too often implemented prior to proper evaluation with respect to tissue optical properties and human safety. Therefore, advances in computational models that describe light propagation and the cellular responses to laser exposure, without the use of animal models, are of considerable interest. Here, a physics-based laser-tissue interaction model was developed to predict the spatial and temporal temperature and pressure rise during laser exposure to biological tissues. Our new model also takes into account the dynamic nature of tissue optical properties and their impact on the induced temperature and pressure profiles. The laser-induced retinal damage is attributed to the formation of microbubbles formed around melanosomes in the retinal pigment epithelium (RPE) and the damage mechanism is assumed to be photo-thermal. Selective absorption by melanin creates these bubbles that expand and collapse around melanosomes, destroying cell membranes and killing cells. The Finite Element (FE) approach taken provides suitable ground for modeling localized pigment absorption which leads to a non-uniform temperature distribution within pigmented cells following laser pulse exposure. These hot-spots are sources for localized thermo-elastic stresses which lead to rapid localized expansions that manifest themselves as microbubbles and lead to microcavitations. Model predictions for the interaction of lasers at wavelengths of 193, 694, 532, 590, 1314, 1540, 2000, and 2940 nm with biological tissues were generated and comparisons were made with available experimental data for the retina

  6. Mechanical properties and in vitro biological response to porous titanium alloys prepared for use in intervertebral implants.

    PubMed

    Caparrós, C; Guillem-Martí, J; Molmeneu, M; Punset, M; Calero, J A; Gil, F J

    2014-11-01

    The generation of titanium foams is a promising strategy for modifying the mechanical properties of intervertebral reinforcements. Thus, the aim of this study was to compare the in vitro biological response of Ti6Al4V alloys with different pore sizes for use in intervertebral implants in terms of the adhesion, proliferation, and differentiation of pre-osteoblastic cells. We studied the production of Ti6Al4V foams by powder metallurgy and the biological responses to Ti6Al4V foams were assessed in terms of different pore interconnectivities and elastic moduli. The Ti6Al4V foams obtained had similar porosities of approximately 34%, but different pore sizes (66 µm for fine Ti6Al4V and 147 µm for coarse Ti6Al4V) due to the sizes of the microsphere used. The Ti6Al4V foams had a slightly higher Young׳s modulus compared with cancellous bone. The dynamic mechanical properties of the Ti6Al4V foams were slightly low, but these materials can satisfy the requirements for intervertebral prosthesis applications. The cultured cells colonized both sizes of microspheres near the pore spaces, where they occupied almost the entire area of the microspheres when the final cell culture time was reached. No statistical differences in cell proliferation were observed; however, the cells filled the pores on fine Ti6Al4V foams but they only colonized the superficial microspheres, whereas the cells did not fill the pores on coarse Ti6Al4V foams but they were distributed throughout most of the material. In addition, the microspheres with wide pores (coarse Ti6Al4V) stimulated higher osteoblast differentiation, as demonstrated by the Alcaline Phosphatase (ALP) activity. Our in vitro results suggest that foams with wide pore facilitate internal cell colonization and stimulate osteoblast differentiation. PMID:25108271

  7. Comparison of biological activity of phenolic fraction from roots of Alhagi maurorum with properties of commercial phenolic extracts and resveratrol.

    PubMed

    Olas, Beata; Hamed, Arafa I; Oleszek, Wieslaw; Stochmal, Anna

    2015-01-01

    Phenolic compounds have different biological properties, including antioxidative activities, but they may also be prooxidants. The effect of phenolic fraction from roots of Alhagi maurorum on oxidative protein/lipid damages (determined by such parameters as levels of protein thiol groups and the concentration of thiobarbituric acid reactive species--TBARS) in human blood platelets and human plasma after treatment with hydrogen peroxide--H2O2 (which is the strong biologic oxidant and inflammatory mediator) was studied in vitro. We also studied the effect of A. maurorum extract on blood platelet activation corresponding to thrombin-induced arachidonic acid pathway. Moreover, the present work was designed to study the effect of A. maurorum extract on selected physiological function of blood platelets--adhesion of blood platelets to collagen in vitro. The action of phenolic fraction from A. maurorum was compared with the selected commercial phenolic extracts: extract from berries of Aronia melanocarpa (Aronox®), extract from bark of Yucca schidigera and monomeric polyphenol-resveratrol (3,4',5-trihydroxystilbene). Exposure of blood platelets or plasma to H2O2 resulted in a decrease of the level of thiol groups in proteins, and an increase of TBARS. In the presence of phenolic fraction from A. maurorum (0.5-50 µg/ml), a reduction of thiol groups oxidation together with the decrease of autoperoxidation of lipids and lipid peroxidation caused by H2O2 or thrombin was observed. The inhibitory, concentration-dependent effects of A. maurorum extract on adhesion of thrombin-activated platelets to collagen were also found. The phenolic fraction from A. maurorum acts as an antioxidant and can be useful as the natural factor protecting against diseases associated with oxidative stress. Tested fraction from A. maurorum has more effective antioxidative activity and antiplatelet properties than aronia extract or other commercial extract, however differences between their actions

  8. Coypu insulin. Primary structure, conformation and biological properties of a hystricomorph rodent insulin.

    PubMed Central

    Bajaj, M; Blundell, T L; Horuk, R; Pitts, J E; Wood, S P; Gowan, L K; Schwabe, C; Wollmer, A; Gliemann, J; Gammeltoft, S

    1986-01-01

    Insulin from a hystricomorph rodent, coypu (Myocaster coypus), was isolated and purified to near homogeneity. Like the other insulins that have been characterized in this Suborder of Rodentia, coypu insulin also exhibits a very low (3%) biological potency, relative to pig insulin, on lipogenesis in isolated rat fat-cells. The receptor-binding affinity is significantly higher (5-8%) in rat fat-cells, in rat liver plasma membranes and in pig liver cells, indicating that the efficacy of coypu insulin on receptors is about 2-fold lower than that of pig insulin. The primary structures of the oxidized A- and B-chains were determined, and our sequence analysis confirms a previous report [Smith (1972) Diabetes 21, Suppl. 2, 457-460] that the C-terminus of the A-chain is extended by a single residue (i.e. aspartate-A22), in contrast with most other insulin sequences, which terminate at residue A21. In spite of a large number of amino acid substitutions (relative to mammalian insulins), computer-graphics model-building studies suggest a similar spatial arrangement for coypu insulin to that for pig insulin. The substitution of the zinc-co-ordinating site (B10-His----Gln) along with various substitutions on the intermolecular surfaces involved in the formation of higher aggregates are consistent with the observation that this insulin is predominantly 'monomeric' in nature. The c.d. spectrum of coypu insulin is relatively similar to those of casiragua insulin and of bovine insulin at low concentration. PMID:3541911

  9. Piperazinomycin, a new antifungal antibiotic. I. Fermentation, isolation, characterization and biological properties.

    PubMed

    Tamai, S; Kaneda, M; Nakamura, S

    1982-09-01

    A new antifungal antibiotic, named piperazinomycin, was isolated from the cultured broth of Streptoverticillium olivoreticuli subsp. neoenacticus. The antibiotic was obtained from the mycelial cake by extraction with methanol and also from the broth filtrate by adsorption on Amberlite XAD-2 and subsequent elution with aqueous acetone. The antibitoic is of basic and lipophilic nature and can be extracted with methyl isobutyl ketone at alkaline pH. Its purification was carried out by column chromatography on Sephadex LH-20 and then on Sephadex G-15 followed by preparative thin-layer chromatography on silica gel. The molecular formula of piperazinomycin was determined to be C125H20NsO2 by high resolution mass spectrum and the spectroscopic and chemical properties were examined. Piperazinomycin showed inhibitory activity against fungi and yeasts, especially against Trichophyton. PMID:7142019

  10. Synthesis, and Fluorescence Properties of Coumarin and Benzocoumarin Derivatives Conjugated Pyrimidine Scaffolds for Biological Imaging Applications.

    PubMed

    Al-Masoudi, Najim A; Al-Salihi, Niran J; Marich, Yossra A; Markus, Timo

    2015-11-01

    Series of coumarin and 5,6-benzomcomarin substituted pyrimidine derivatives 11-15 and 22-25 were synthesized, aiming to develop new imaging fluorescent agents. Analogously, treatment of 4-chloropyrimidine analog 16 with coumarin 3-carbohyrazide 5 under MWI condition followed by boiling with NH4OAc in HOAc furnished coumarin-1,2,4-triazolo-pyrimidine analog 18. The fluorescence property was investigated spectrophotometrically in MeOH with Rhodamine 6G as standard dye. All the compounds showed emission in the region between 331 and 495 nm. The quantum yield of all the compounds were found to be weak, except methyl benzocoumarin 3-carboxylate 22 which showed (ΦF = 0.98) in comparison to Rhodamine 6G as standard (ΦF = 0.95). PMID:26477837

  11. Synthesis and biological properties of polyamine modified flavonoids as hepatocellular carcinoma inhibitors.

    PubMed

    Li, Qian; Zhai, Yangyang; Luo, Wen; Zhu, Zixin; Zhang, Xin; Xie, Songqiang; Hong, Chen; Wang, Yuxia; Su, Yabin; Zhao, Jin; Wang, Chaojie

    2016-10-01

    A series of polyamine conjugates of flavonoids with a naphthalene motif were synthesized and evaluated for their anti-hepatocellular carcinoma properties using in vitro and in vivo assays. Compound 8a displayed favorable selectivity between hepatocellular carcinoma cells and normal hepatocyte cells, and the combination of 8a with aspirin resulted in additive inhibition of in vitro tumor cell growth and migration. The 8a-aspirin combination also inhibited H22 liver tumor growth and pulmonary metastasis and improved body weight index in animal models. Preliminary mechanistic studies indicated that 8a increased the expression of apoptosis-related proteins such as p-p38, p-JNK, p53 and Bcl-2, an effect that was further amplified by aspirin. Therefore, a cocktail therapy of flavonoid-polyamine conjugates with aspirin has potential use as an antitumor therapy. PMID:27236067

  12. Synthesis and biological properties of conjugates between fluoroquinolones and a N3''-functionalized pyochelin.

    PubMed

    Noël, Sabrina; Gasser, Véronique; Pesset, Bénédicte; Hoegy, Françoise; Rognan, Didier; Schalk, Isabelle J; Mislin, Gaëtan L A

    2011-12-21

    Pyochelin is a siderophore common to Pseudomonas aeruginosa and several other pathogenic bacteria. A pyochelin functionalized at the N3'' position with a propyl-amine extension was previously synthesized. In the present work we proved that this analog binds FptA, the pyochelin outer membrane receptor, and transports iron(III) efficiently into bacteria. This functionalized pyochelin seemed to be a good candidate for antibiotic vectorization in the framework of a Trojan horse prodrug strategy. In this context, conjugates between pyochelin and three fluoroquinolones (norfloxacin, ciprofloxacin and N-desmethyl-ofloxacin) were synthesized with a spacer arm that was either stable or hydrolyzable in vivo. Some pyochelin-fluoroquinolone conjugates had antibacterial activities in growth inhibition experiments on several P. aeruginosa strains. However, these activities were weaker than those of the antibiotic alone. These properties appeared to be related to both the solubility and bioavailability of conjugates and to the stability of the spacer arm used. PMID:22052022

  13. Mechanical properties of lipid bilayers and regulation of mechanosensitive function: from biological to biomimetic channels.

    PubMed

    Balleza, Daniel

    2012-01-01

    Material properties of lipid bilayers, including thickness, intrinsic curvature and compressibility regulate the function of mechanosensitive (MS) channels. This regulation is dependent on phospholipid composition, lateral packing and organization within the membrane. Therefore, a more complete framework to understand the functioning of MS channels requires insights into bilayer structure, thermodynamics and phospholipid structure, as well as lipid-protein interactions. Phospholipids and MS channels interact with each other mainly through electrostatic forces and hydrophobic matching, which are also crucial for antimicrobial peptides. They are excellent models for studying the formation and stabilization of membrane pores. Importantly, they perform equivalent responses as MS channels: (1) tilting in response to tension and (2) dissipation of osmotic gradients. Lessons learned from pore forming peptides could enrich our knowledge of mechanisms of action and evolution of these channels. Here, the current state of the art is presented and general principles of membrane regulation of mechanosensitive function are discussed. PMID:22790280

  14. Photothermal deflection of laser beam as means to characterize thermal properties of biological tissue: numerical study

    NASA Astrophysics Data System (ADS)

    Gutierrez-Herrera, Enoch; Sánchez-Pérez, Celia; García-Cadena, Carlos A.; Hernández-Ruiz, Joselín.

    2015-08-01

    Non-subjective and early diagnostic technique for liver fibrosis may decrease morbidity in patients and reduce medical costs. Liver fibrosis results in changes in density and thermal properties of tissue. In this work, we evaluate numerically the feasibility of using the optical beam deflection method (OBDM) by means of a thermo-optic material in contact with liver tissue to quantitate changes in thermal conduction. We use the finite-difference method to model the heat transfer in liver and acrylic slab. The response required for thermal characterization for different fibrosis stages is assessed by calculating the deflection angle using ray trace analysis. Numerical study shows the potential of the OBDM for developing an optical-integrated sensor as non-subjective diagnostic technique for liver fibrosis.

  15. The Self-Referential Genetic Code is Biologic and Includes the Error Minimization Property

    NASA Astrophysics Data System (ADS)

    Guimarães, Romeu Cardoso

    2015-06-01

    The distribution of the triplet to amino acid correspondences in the genetic code matrix contains blocks of similarity. There are (a) groups of similar triplets coding for the same amino acid, which is called code degeneracy, and (b) clusters of similar amino acids corresponding to similar triplets. Processes that led to this regionalization have been investigated through a variety of perspectives but no consensus has been reached and no model has been convincing enough to drive experimental tests. Most traditional has been the hypothesis that the code was derived from the standard evolutionary processes of testing variations in the correspondences through the fitness measure of reaching distributions in the matrix space in an optimal manner so that the effects of mutations on protein phenotypes would be minimized, that is, with reduction of the intensity or of the deviant quality of the functional alterations associated with variations. In contrast, the self-referential model for the formation of the code is based on an original regionalization of characters through the concerted superposition of the two components of the encodings: the four modules of dimers of tRNAs are occupied sequentially by sets of amino acids that are also sequentially devoted to fulfilling specific functions in the protein sites and motifs to which they preferentially belong. Therewith, part (b) of the error-minimizing property follows. Part (a) of the property, the code degeneracy, is derived from the synthetase character of developing specificities directed initially to the principal dinucleotides of the triplets, resulting in tetracodonic degeneracy. This was later partly modified during evolution according to the developments of codon usage and the introduction of new amino acids.

  16. Trypanosoma cruzi I and IV Stocks from Brazilian Amazon Are Divergent in Terms of Biological and Medical Properties in Mice

    PubMed Central

    Monteiro, Wuelton Marcelo; Margioto Teston, Ana Paula; Gruendling, Ana Paula; dos Reis, Daniele; Gomes, Mônica Lúcia; Marques de Araújo, Silvana; Bahia, Maria Terezinha; Costa Magalhães, Laylah Kelre; de Oliveira Guerra, Jorge Augusto; Silveira, Henrique; de Ornelas Toledo, Max Jean; Vale Barbosa, Maria das Graças

    2013-01-01

    Background In the Brazilian Amazon, clinical and epidemiological frameworks of Chagas disease are very dissimilar in relation to the endemic classical areas of transmission, possibly due to genetic and biological characteristics of the circulating Trypanosoma cruzi stocks. Twenty six T. cruzi stocks from Western Amazon Region attributed to the TcI and TcIV DTUs were comparatively studied in Swiss mice to test the hypothesis that T. cruzi clonal structure has a major impact on its biological and medical properties. Methodology/Principal Findings Seventeen parameters were assayed in mice infected with 14 T. cruzi strains belonging to DTU TcI and 11 strains typed as TcIV. In comparison with TcI, TcIV stocks promoted a significantly shorter pre-patent period (p<0.001), a longer patent period (p<0.001), higher values of mean daily parasitemia (p = 0.009) and maximum of parasitemia (p = 0.015), earlier days of maximum parasitemia (p<0.001) and mortality (p = 0.018), higher mortality rates in the acute phase (p = 0.047), higher infectivity rates (p = 0.002), higher positivity in the fresh blood examination (p<0.001), higher positivity in the ELISA at the early chronic phase (p = 0.022), and a higher positivity in the ELISA at the late chronic phase (p = 0.003). On the other hand TcI showed higher values of mortality rates in the early chronic phase (p = 0.014), higher frequency of mice with inflammatory process in any organ (p = 0.005), higher frequency of mice with tissue parasitism in any organ (p = 0.027) and a higher susceptibility to benznidazole (p = 0.002) than TcIV. Survival analysis showing the time elapsed from the day of inoculation to the beginning of the patent period was significantly shorter for TcIV strains and the death episodes triggered following the infection with TcI occurred significantly later in relation to TcIV. The notable exceptions come from positivity in the hemocultures and PCR, for which the

  17. Solubility properties in polymers and biological media. 7. An analysis of toxicant properties that influence inhibition of bioluminescence in photobacterium phosphoreum (the Microtox test)

    SciTech Connect

    Kamlet, M.J.; Doherty, R.M.; Veith, G.D.; Taft, R.W.; Abraham, M.H.

    1986-07-01

    Inhibition of bioluminescence in Photobacterium phosphoreum (the Microtox test) has been proposed as a cost-effective prescreening procedure to eliminate the relatively more innocuous chemicals from testing programs for toxicities of organic chemicals to fish. The biological response, as a function of toxicant properties, is given by log EC/sub 50/ (in ..mu..molL) = 7.61 - 4.11 anti V100 - 1.54 ..pi..* + 3.94..beta.. - 1.51..cap alpha../sub m/ n = 38, r = 0.987, SD = 0.28 where anti V is the solute molar volume and ..pi..*, ..beta.., and ..cap alpha../sub m/ are the solvatochromic parameters that measure dipolaritypolarizability, hydrogen-bond acceptor basicity, and hydrogen-bond donor acidity of the solute (toxicant). The above equation applies to compounds that act by a nonreactive toxicity mechanism, and it is suggested that for certain compounds, which are outliers relative to the above equation, reactive toxicity properties mask the effects of the nonreactive mechanism. The above equation is compared with a correlation of log EC/sub 50/ with octanolwater partition coefficients. 25 references, 2 figures, 2 tables.

  18. Depleted uranium dust from fired munitions: physical, chemical and biological properties.

    PubMed

    Mitchel, R E J; Sunder, S

    2004-07-01

    This paper reports physical, chemical and biological analyses of samples of dust resulting from munitions containing depleted uranium (DU) that had been live-fired and had impacted an armored target. Mass spectroscopic analysis indicated that the average atom% of U was 0.198 +/- 0.10, consistent with depleted uranium. Other major elements present were iron, aluminum, and silicon. About 47% of the total mass was particles with diameters <300 microm, of which about 14% was <10 microm. X-ray diffraction analysis indicated that the uranium was present in the sample as uranium oxides-mainly U3O7 (47%), U3O8 (44%) and UO2 (9%). Depleted uranium dust, instilled into the lungs or implanted into the muscle of rats, contained a rapidly soluble uranium component and a more slowly soluble uranium component. The fraction that underwent dissolution in 7 d declined exponentially with increasing initial burden. At the lower lung burdens tested (<15 microg DU dust/lung) about 14% of the uranium appeared in urine within 7 d. At the higher lung burdens tested (~80-200 microg DU dust/lung) about 5% of the DU appeared in urine within 7 d. In both cases about 50% of that total appeared in urine within the first day. DU implanted in muscle similarly showed that about half of the total excreted within 7 d appeared in the first day. At the lower muscle burdens tested (<15 microg DU dust/injection site) about 9% was solubilized within 7 d. At muscle burdens >35 microg DU dust/injection site about 2% appeared in urine within 7 d. Natural uranium (NU) ore dust was instilled into rat lungs for comparison. The fraction dissolving in lung showed a pattern of exponential decline with increasing initial burden similar to DU. However, the decline was less steep, with about 14% appearing in urine for lung burdens up to about 200 microg NU dust/lung and 5% at lung burdens >1,100 microg NU dust/lung. NU also showed both a fast and a more slowly dissolving component. At the higher lung burdens of both

  19. Rheological and biological properties of a hydrogel support for cells intended for intervertebral disc repair

    PubMed Central

    2012-01-01

    Background Cell-based approaches towards restoration of prolapsed or degenerated intervertebral discs are hampered by a lack of measures for safe administration and placement of cell suspensions within a treated disc. In order to overcome these risks, a serum albumin-based hydrogel has been developed that polymerizes after injection and anchors the administered cell suspension within the tissue. Methods A hydrogel composed of chemically activated albumin crosslinked by polyethylene glycol spacers was produced. The visco-elastic gel properties were determined by rheological measurement. Human intervertebral disc cells were cultured in vitro and in vivo in the hydrogel and their phenotype was tested by reverse-transcriptase polymerase chain reaction. Matrix production and deposition was monitored by immuno-histology and by biochemical analysis of collagen and glycosaminoglycan deposition. Species specific in situ hybridization was performed to discriminate between cells of human and murine origin in xenotransplants. Results The reproducibility of the gel formation process could be demonstrated. The visco-elastic properties were not influenced by storage of gel components. In vitro and in vivo (subcutaneous implants in mice) evidence is presented for cellular differentiation and matrix deposition within the hydrogel for human intervertebral disc cells even for donor cells that have been expanded in primary monolayer culture, stored in liquid nitrogen and re-activated in secondary monolayer culture. Upon injection into the animals, gels formed spheres that lasted for the duration of the experiments (14 days). The expression of cartilage- and disc-specific mRNAs was maintained in hydrogels in vitro and in vivo, demonstrating the maintenance of a stable specific cellular phenotype, compared to monolayer cells. Significantly higher levels of hyaluronan synthase isozymes-2 and -3 mRNA suggest cell functionalities towards those needed for the support of the regeneration of

  20. Biological diversity, indigenous knowledge, drug discovery and intellectual property rights: creating reciprocity and maintaining relationships.

    PubMed

    King, S R; Carlson, T J; Moran, K

    1996-04-01

    When new plant-derived therapeutics based on indigenous knowledge are being explored, it is important that the pharmaceutical companies return benefits to the native populations and the local governments from which the research material was obtained. When a potentially marketable plant product is being developed, it is essential that equitable agreements have already been established between the pharmaceutical companies and the people and/or countries from which this indigenous knowledge was acquired. Equally important is the commitment to provide immediate reciprocity that will enhance the welfare, the biocultural diversity and the well-being of the forest peoples. These measures should commence when a research project begins and continue during its duration. The development of these measures must be based upon the expressed needs of the indigenous communities. The relationship between the stability of the rain forest biocultural diversity, the creation and development of agro-forest resources and the long term benefits to the forest people is highlighted. Examples of initiatives taken by Shaman Pharmaceuticals Inc. and the Healing Forest Conservancy are described and discussed in the context of exploring appropriate use of intellectual property law to address the ethical issues facing all business and research groups working in the tropics. PMID:9213630

  1. Origin and biological properties of a new BALB/c mouse sarcoma virus.

    PubMed Central

    Aaronson, S A; Barbacid, M

    1978-01-01

    A focus-forming virus previously isolated from a BALB/c mouse hemangiosarcoma has been shown to be replication defective. Analysis of individual BALB/c mouse sarcoma virus (BALB-MSV) nonproducer transformants for expression of helper virus-coded proteins revealed genetically stable variants that expressed two, three, or all four gag gene products in the absence of detectable helper viral env gene expression. The type-specific antigenic determinants of helper viral proteins encoded by the BALB-MSV genome and by the B-tropic virus isolated from the BALB-MSV stock were demonstrated to be indistinguishable from those of BALB:virus-1, a known endogenous virus of BALB/c cells. These findings imply that a BALB/c endogenous virus was involved in the generation of BALB-MSV. By the same immunological approach, the presence of at least a portion of the Moloney-MuLV gag gene has been identified in two other transforming viruses--Moloney-MSV and Abelson lymphosarcoma virus--previously isolated from the BALB/c strain. The tissue culture properties of cells transformed by these defective viruses were also shown to be distinguishable. These findings indicate that transforming virus isolates of the same inbred strain differ in their transforming activities as well as in the helper viral sequences stably associated with their genomes. Images PMID:80461

  2. A Comparison between Characterization and Biological Properties of Brazilian Fresh and Aged Propolis

    PubMed Central

    Schmidt, Eduardo Morgado; Stock, Daniele; Chada, Fabio José Garcia; Finger, Daiane; Christine Helena Frankland Sawaya, Alexandra; Eberlin, Marcos Nogueira; Felsner, Maria Lurdes; Quináia, Sueli Pércio; Torres, Yohandra Reyes

    2014-01-01

    Objective. As propolis is a highly valued bee product, we aimed to verify the quality of aged propolis, investigating their phenolic and flavonoid composition, levels of toxic metals, radical scavenging and antimicrobial activities. Material and Methods. Samples of fresh and aged propolis of six different beekeepers, from the same geographical location, were investigated in terms of their phenolic and flavonoid composition and levels of Pb, Cd, and Cr, as well as radical scavenging and antimicrobial activities. Results. The two groups of propolis had similar qualitative composition by HPLC-PDA and ESI(-)-MS. Fresh propolis and aged propolis show no differences when average values of extraction yield, flavonoids, EC50, or MIC were compared and both types of propolis showed good antimicrobial activity at low concentrations. Only levels of phenolic compounds were higher in fresh propolis. Conclusion. The propolis samples considered in this study, aged or fresh, had similar qualitative composition, although they were collected in different periods. Samples only differed in their levels of total phenolic content. Moreover, aged propolis conserves significant radical scavenging and antimicrobial properties. We suggest that aged propolis should not be discarded but explored for alternative applications. PMID:25530958

  3. TiO2 nanocomposites: Preparation, characterization, mechanical and biological properties

    NASA Astrophysics Data System (ADS)

    Koşarsoy, Gözde; Şen, Elif Hilal; Aksöz, Nilüfer; İde, Semra; Aksoy, Hüsnü

    2014-11-01

    Some novel nanocomposites, which contain different concentrations of TiO2 nanopowders, were firstly prepared by using marble dust with convenient chemical components. Their nano structures characterized and distributions of the nano-aggregations related with internal structural content of the samples have been determined by X-ray Scattering Methods (SAXS and WAXS) and mechanical properties were determined by using strain-stress measurements to increase their potential usage possibility as building materials in health and research centers. In the last and important part of the study, Candida albicans and Aspergillus niger which are a significant risk to medical patients were used to investigate originally prepared nanostructured samples' photocatalyst effect. During the last part of the study, effect of UV and visible light on photocatalyst nanocomposites were also researched. Heterogeneous photocatalysts can carry out advanced oxidation processes used for an antimicrobial effect on microorganisms. TiO2 nanoparticles as one of heterogeneous photocatalysts have been shown to exhibit strong cytotoxicity when exposed to UV and visible light.

  4. Highly Flexible Platform for Tuning Surface Properties of Silica Nanoparticles and Monitoring Their Biological Interaction.

    PubMed

    Ojea-Jiménez, Isaac; Urbán, Patricia; Barahona, Francisco; Pedroni, Matteo; Capomaccio, Robin; Ceccone, Giacomo; Kinsner-Ovaskainen, Agnieszka; Rossi, François; Gilliland, Douglas

    2016-02-24

    The following work presents a simple, reliable and scalable seeding-growth methodology to prepare silica nanoparticles (SiO2 NPs) (20, 30, 50 and 80 nm) directly in aqueous phase, both as plain- as well as fluorescent-labeled silica. The amount of fluorescent label per particle remained constant regardless of size, which facilitates measurements in terms of number-based concentrations. SiO2 NPs in dispersion were functionalized with an epoxysilane, thus providing a flexible platform for the covalent linkage of wide variety of molecules under mild experimental conditions. This approach was validated with ethylenediamine, two different amino acids and three akylamines to generate a variety of surface modifications. Accurate characterization of particle size, size distributions, morphology and surface chemistry is provided, both for as-synthesized particles and after incubation in cell culture medium. The impact of physicochemical properties of SiO2 NPs was investigated with human alveolar basal epithelial cells (A549) such as the effect in cytotoxicity, cell internalization and membrane interaction. PMID:26779668

  5. Ferrocenyl-cymantrenyl hetero-bimetallic chalcones: Synthesis, structure and biological properties

    NASA Astrophysics Data System (ADS)

    Mishra, Sasmita; Tirkey, Vijaylakshmi; Ghosh, Avishek; Dash, Hirak R.; Das, Surajit; Shukla, Madhulata; Saha, Satyen; Mobin, Sheikh M.; Chatterjee, Saurav

    2015-04-01

    Two new ferrocenyl-cymantrenyl bimetallic chalcones, [(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)Fe(η5-C5H5)] (1) and [{(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)}2Fe] (2) have been synthesized. Their reactivity study with triphenylphosphine and bis-(diphenylphosphino)ferrocene led to the isolation of phosphine substituted bimetallic chalcones (3-6). Single crystal X-ray structural characterization for 1 and its phosphine analogue (3) reveals their different conformational identity with anti-conformation for 1, while syn-conformation for 3. Investigation of antimalarial and antibacterial activities was carried out for compounds 1 and 2 against two strains of Plasmodium falciparum (3D7, K1) and four bacterial strains. TD-DFT calculation was performed for compound 1 and electrochemical properties were studied for bimetallic chalcone compounds by cyclic voltammetric technique.

  6. Mechanical property and biological performance of electrospun silk fibroin-polycaprolactone scaffolds with aligned fibers.

    PubMed

    Yuan, Han; Shi, Hongfei; Qiu, Xushen; Chen, Yixin

    2016-01-01

    The mechanical strength, biocompatibility, and sterilizability of silk fibroin allow it to be a possible candidate as a natural bone regenerate material. To improve mechanical character and reinforce the cell movement induction, silk fibroin (SF)-polycaprolactone (PCL) alloy was fabricated by electrospinning techniques with a rotating collector to form aligned fibrous scaffolds and random-oriented scaffolds. The scanning electron microscope image of the scaffold and the mechanical properties of the scaffold were investigated by tensile mechanical tests, which were compared to random-oriented scaffolds. Furthermore, mesenchymal stem cells were planted on these scaffolds to investigate the biocompatibility, elongation, and cell movement in situ. Scanning electron microscopy shows that 91% fibers on the aligned fibroin scaffold were distributed between the dominant direction ±10°. With an ideal support for stem cell proliferation in vitro, the aligned fibrous scaffold induces cell elongation at a length of 236.46 ± 82 μm and distribution along the dominant fiber direction with a cell alignment angle at 6.57° ± 4.45°. Compared with random-oriented scaffolds made by artificial materials, aligned SF-PCL scaffolds could provide a moderate mesenchymal stem cell engraftment interface and speed up early stage cell movement toward the bone defect. PMID:26588014

  7. Development of salmon collagen vascular graft: mechanical and biological properties and preliminary implantation study.

    PubMed

    Nagai, Nobuhiro; Nakayama, Yasuhide; Zhou, Yue-Min; Takamizawa, Keiichi; Mori, Kazuo; Munekata, Masanobu

    2008-11-01

    Elastic salmon collagen (SC) vascular grafts were prepared by incubating a mixture of acidic SC solution and a fibrillogenesis-inducing buffer containing a crosslinking agent [water-soluble carbodiimide (WSC)] in a tubular mold at 4 degrees C for 24 h and then at 60 degrees C for 5 min. Subsequently, re-crosslinking in ethanol solution containing WSC was performed. The dimension of the SC grafts was easily controlled by changing the size of the mold used. The compliance (stiffness parameter: beta) and burst strength of the SC grafts (internal diameter, 2 mm; length, 20 mm; and wall thickness, 0.75 mm) that were prepared for implantation were 18.2 and 1434 mmHg, respectively; both these values were comparable with those of native vessels. Upon placement in rat subcutaneous pouches, the SC grafts were gradually biodegraded with little inflammatory reaction. The SC grafts were preliminarily implanted in rat abdominal aortas by using specially designed vascular connecting system. This system was used because the graft exhibited easy tearing and thus inadequate suturability. There was neither aneurysm formation nor graft rupture, but mild thrombus formation was seen within the 4-week observation period. These grafts may be ideal for use in regenerative medicine because we believe that SC would be completely replaced with native vascular tissues after implantation, although further improvement in the mechanical properties of the graft is needed for anastomosis. PMID:18478534

  8. Physical and biological properties of the ion beam irradiated PMMA-based composite films

    NASA Astrophysics Data System (ADS)

    Shanthini, G. M.; Martin, Catherine Ann; Sakthivel, N.; Veerla, Sarath Chandra; Elayaraja, K.; Lakshmi, B. S.; Asokan, K.; Kanjilal, D.; Kalkura, S. Narayana

    2015-02-01

    Polymethyl methacrylate (PMMA) and PMMA-hydroxyapatite (PMMA-HAp) composite films, prepared by the solvent evaporation method were irradiated with 100 MeV Si7+ ions. Crystallographic, morphological and the functional groups of the pristine and irradiated samples were studied using glancing incident X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) respectively. SEM reveals the creation of pores, along with an increase in porosity and cluster size on irradiation. Decrease in crystalline nature and crystallite size with an increase in ion fluence was observed from GIXRD patterns. The surface roughness and the wettability of the material were also enhanced, which could favour the cell-material interaction. The irradiated samples adsorbed significantly greater amount of proteins than pristine. Also, irradiation does not produce any toxic byproducts or leachants, and maintains the viability of 3T3 cells. The response of the irradiated samples towards biomedical applications was demonstrated by the improved antimicrobial activity, haemocompatibility and cytocompatibility. Swift heavy ion irradiation (SHI) could be an effective tool to modify and engineer the surface properties of the polymers to enhance the biocompatibility.

  9. Improvement of physical, chemical, and biological properties of aridisol from Botswana by the incorporation of torrefied biomass

    PubMed Central

    Ogura, Tatsuki; Date, Yasuhiro; Masukujane, Masego; Coetzee, Tidimalo; Akashi, Kinya; Kikuchi, Jun

    2016-01-01

    Effective use of agricultural residual biomass may be beneficial for both local and global ecosystems. Recently, biochar has received attention as a soil enhancer, and its effects on plant growth and soil microbiota have been investigated. However, there is little information on how the physical, chemical, and biological properties of soil amended with biochar are affected. In this study, we evaluated the effects of the incorporation of torrefied plant biomass on physical and structural properties, elemental profiles, initial plant growth, and metabolic and microbial dynamics in aridisol from Botswana. Hemicellulose in the biomass was degraded while cellulose and lignin were not, owing to the relatively low-temperature treatment in the torrefaction preparation. Water retentivity and mineral availability for plants were improved in soils with torrefied biomass. Furthermore, fertilization with 3% and 5% of torrefied biomass enhanced initial plant growth and elemental uptake. Although the metabolic and microbial dynamics of the control soil were dominantly associated with a C1 metabolism, those of the 3% and 5% torrefied biomass soils were dominantly associated with an organic acid metabolism. Torrefied biomass was shown to be an effective soil amendment by enhancing water retentivity, structural stability, and plant growth and controlling soil metabolites and microbiota. PMID:27313139

  10. Investigation of the Biophysical and Cell Biological Properties of Ferroportin, a Multi-Pass Integral Membrane Protein Iron Exporter

    PubMed Central

    Rice, Adrian E.; Mendez, Michael J.; Hokanson, Craig A.; Rees, Douglas C.; Björkman, Pamela J.

    2009-01-01

    Ferroportin is a multi-pass membrane protein that serves as an iron exporter in many vertebrate cell types. Ferroportin-mediated iron export is controlled by the hormone hepcidin, which binds ferroportin, causing its internalization and degradation. Mutations in ferroportin cause a form of the iron overload disease hereditary hemochromatosis. Relatively little is known about ferroportin’s properties or the mechanism by which mutations cause disease. Here we expressed and purified human ferroportin to characterize its biochemical/biophysical properties in solution and conducted cell biological studies in mammalian cells. We show that purified, detergent-solubilized ferroportin was a well-folded monomer that bound hepcidin. In cell membranes, the N- and C-termini were both cytosolic, implying an even number of transmembrane regions, and ferroportin was mainly localized to the plasma membrane. Hepcidin addition resulted in a redistribution of ferroportin to intracellular compartments that labeled with early endosomal and lysosomal, but not Golgi, markers and that trafficked along microtubules. An analysis of 16 disease-related ferroportin mutants revealed that all formed well-folded monomers that localized to the plasma membrane, but some were resistant to hepcidin-induced internalization. The characterizations reported here form a basis upon which models for ferroportin’s role in regulating iron homeostasis in health and disease can be interpreted. PMID:19150361

  11. Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

    PubMed Central

    Khan, Pintu Kumar; Mahato, Arnab; Kundu, Biswanath; Nandi, Samit K.; Mukherjee, Prasenjit; Datta, Someswar; Sarkar, Soumya; Mukherjee, Jayanta; Nath, Shalini; Balla, Vamsi K.; Mandal, Chitra

    2016-01-01

    Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. PMID:27604654

  12. Improvement of physical, chemical, and biological properties of aridisol from Botswana by the incorporation of torrefied biomass.

    PubMed

    Ogura, Tatsuki; Date, Yasuhiro; Masukujane, Masego; Coetzee, Tidimalo; Akashi, Kinya; Kikuchi, Jun

    2016-01-01

    Effective use of agricultural residual biomass may be beneficial for both local and global ecosystems. Recently, biochar has received attention as a soil enhancer, and its effects on plant growth and soil microbiota have been investigated. However, there is little information on how the physical, chemical, and biological properties of soil amended with biochar are affected. In this study, we evaluated the effects of the incorporation of torrefied plant biomass on physical and structural properties, elemental profiles, initial plant growth, and metabolic and microbial dynamics in aridisol from Botswana. Hemicellulose in the biomass was degraded while cellulose and lignin were not, owing to the relatively low-temperature treatment in the torrefaction preparation. Water retentivity and mineral availability for plants were improved in soils with torrefied biomass. Furthermore, fertilization with 3% and 5% of torrefied biomass enhanced initial plant growth and elemental uptake. Although the metabolic and microbial dynamics of the control soil were dominantly associated with a C1 metabolism, those of the 3% and 5% torrefied biomass soils were dominantly associated with an organic acid metabolism. Torrefied biomass was shown to be an effective soil amendment by enhancing water retentivity, structural stability, and plant growth and controlling soil metabolites and microbiota. PMID:27313139

  13. Improvement of physical, chemical, and biological properties of aridisol from Botswana by the incorporation of torrefied biomass

    NASA Astrophysics Data System (ADS)

    Ogura, Tatsuki; Date, Yasuhiro; Masukujane, Masego; Coetzee, Tidimalo; Akashi, Kinya; Kikuchi, Jun

    2016-06-01

    Effective use of agricultural residual biomass may be beneficial for both local and global ecosystems. Recently, biochar has received attention as a soil enhancer, and its effects on plant growth and soil microbiota have been investigated. However, there is little information on how the physical, chemical, and biological properties of soil amended with biochar are affected. In this study, we evaluated the effects of the incorporation of torrefied plant biomass on physical and structural properties, elemental profiles, initial plant growth, and metabolic and microbial dynamics in aridisol from Botswana. Hemicellulose in the biomass was degraded while cellulose and lignin were not, owing to the relatively low-temperature treatment in the torrefaction preparation. Water retentivity and mineral availability for plants were improved in soils with torrefied biomass. Furthermore, fertilization with 3% and 5% of torrefied biomass enhanced initial plant growth and elemental uptake. Although the metabolic and microbial dynamics of the control soil were dominantly associated with a C1 metabolism, those of the 3% and 5% torrefied biomass soils were dominantly associated with an organic acid metabolism. Torrefied biomass was shown to be an effective soil amendment by enhancing water retentivity, structural stability, and plant growth and controlling soil metabolites and microbiota.

  14. Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds.

    PubMed

    Khan, Pintu Kumar; Mahato, Arnab; Kundu, Biswanath; Nandi, Samit K; Mukherjee, Prasenjit; Datta, Someswar; Sarkar, Soumya; Mukherjee, Jayanta; Nath, Shalini; Balla, Vamsi K; Mandal, Chitra

    2016-01-01

    Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. PMID:27604654

  15. Effects of oyster shell on soil chemical and biological properties and cabbage productivity as a liming materials.

    PubMed

    Lee, Chang Hoon; Lee, Do Kyoung; Ali, Muhammad Aslam; Kim, Pil Joo

    2008-12-01

    Oyster shell, a byproduct of shellfish-farming in Korea and containing a high amount of CaCO(3), has a high potential to be used as a liming material in agriculture. However, the agricultural utilization of oyster shell is limited due to its high concentration NaCl. The oyster-shell meal collected had a low concentration of water soluble NaCl (mean 2.7 g kg(-1)), which might be a result of stacking the material for 6 months in the open field. It has a very similar liming potential with calcium carbonate, with 3.4 and 3.8 Mg ha(-1) for silt loam (SiL, pH 6.2) and sandy loam (SL, pH 5.8) to bring the soil pH to 6.5, respectively. To determine the effect of crushed oyster-shell meal on improving soil chemical and biological properties and crop plant productivity, oyster-shell meal was applied at rates of 0, 4, 8, 12, and 16 Mg ha(-1) before transplanting Chinese cabbage (Brassica campestris L.) in the two soils mentioned above. Soil pH was significantly increased to 6.9 and 7.4 by 16 Mg ha(-1) shell meal application (4 times higher level than the recommendation) in SiL and SL, respectively, at harvesting stage. The effect of liming was found higher in SL compared to SiL soil, probably due to the different buffering capacity of the two soils. The concentration of NaCl and EC value of soils were found slightly increased with shell meal applications, but no salt damage was observed. Oyster-shell meal application increased soil organic matter, available P, and exchangeable cations concentrations. The improved soil pH and nutrient status significantly increased the microbial biomass C and N concentrations and stimulated soil enzyme activities. With the exception of acid phosphomonoesterase (PMEase) activity, which decreased with increasing soil pH in SL but slightly increased in SiL, the activities of urease and alkali PMEase increased markedly with increasing soil pH by shell meal application. The improved soil chemical and biological properties resulted in increased crop

  16. Fabrication and physical and biological properties of fibrin gel derived from human plasma

    NASA Astrophysics Data System (ADS)

    Zhao, Haiguang; Ma, Lie; Zhou, Jie; Mao, Zhengwei; Gao, Changyou; Shen, Jiacong

    2008-03-01

    The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 °C, which is about 30 °C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of ~50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml-1) and thrombin (5 U ml-1) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.

  17. Phase stability and biological property evaluation of plasma sprayed hydroxyapatite coatings for orthopedic and dental applications.

    PubMed

    Vahabzadeh, Sahar; Roy, Mangal; Bandyopadhyay, Amit; Bose, Susmita

    2015-04-01

    In this work we have investigated the effects of strontium (Sr) dopant on in vitro protein release kinetics and in vivo osteogenic properties of plasma sprayed hydroxyapatite (HA) coatings, along with their dissolution behavior. Plasma sprayed HA coatings are widely used in load-bearing implants. Apart from osseointegration, the new generation of HA coating is expected to deliver biomolecules and/or drugs that can induce osteoinduction. This paper reports the preparation of crystalline and amorphous HA coatings on commercially pure titanium (Cp-Ti) using inductively coupled radio frequency (RF) plasma spray, and their stability at different solution pH. Coatings prepared at 110 mm working distance from the nozzle showed an average Ca ion release of 18 and 90 ppm in neutral and acidic environments, respectively. Decreasing the working distance to 90 mm resulted in the formation of a coating with less crystalline HA and phases with higher solubility products, and consequently higher dissolution over 32 days. A 92% release of a model protein bovine serum albumin (BSA) in phosphate buffer with pH of 7.4 was measured for Sr-doped HA (Sr-HA) coating, while only a 72% release could be measured for pure HA coating. Distortion of BSA during adsorption on coatings revealed a strong interaction between the protein and the coating, with an increase in α-helix content. Osteoid formation was found on Sr-HA implants as early as 7 weeks post implantation compared to HA coated and uncoated Ti implants. After 12 weeks post implantation, osteoid new bone was formed on HA implants; whereas, bone mineralization started on Sr-HA samples. While no osteoid was formed on bare Ti surfaces, bone was completely mineralized on HA and Sr-HA coatings after 16 weeks post implantation. Our results show that both phase stability and chemistry can have a significant influence toward in vitro and in vivo response of HA coatings on Ti implants. PMID:25638672

  18. Improving the pharmacokinetic properties of biologics by fusion to an anti-HSA shark VNAR domain

    PubMed Central

    Müller, Mischa R.; Saunders, Kenneth; Grace, Christopher; Jin, Macy; Piche-Nicholas, Nicole; Steven, John; O’Dwyer, Ronan; Wu, Leeying; Khetemenee, Lam; Vugmeyster, Yulia; Hickling, Timothy P.; Tchistiakova, Lioudmila; Olland, Stephane; Gill, Davinder; Jensen, Allan; Barelle, Caroline J.

    2012-01-01

    Advances in recombinant antibody technology and protein engineering have provided the opportunity to reduce antibodies to their smallest binding domain components and have concomitantly driven the requirement for devising strategies to increase serum half-life to optimise drug exposure, thereby increasing therapeutic efficacy. In this study, we adopted an immunization route to raise picomolar affinity shark immunoglobulin new antigen receptors (IgNARs) to target human serum albumin (HSA). From our model shark species, Squalus acanthias, a phage display library encompassing the variable binding domain of IgNAR (VNAR) was constructed, screened against target, and positive clones were characterized for affinity and specificity. N-terminal and C-terminal molecular fusions of our lead hit in complex with a naïve VNAR domain were expressed, purified and exhibited the retention of high affinity binding to HSA, but also cross-selectivity to mouse, rat and monkey serum albumin both in vitro and in vivo. Furthermore, the naïve VNAR had enhanced pharmacokinetic (PK) characteristics in both N- and C-terminal orientations and when tested as a three domain construct with naïve VNAR flanking the HSA binding domain at both the N and C termini. Molecules derived from this platform technology also demonstrated the potential for clinical utility by being available via the subcutaneous route of delivery. This study thus demonstrates the first in vivo functional efficacy of a VNAR binding domain with the ability to enhance PK properties and support delivery of multifunctional therapies. PMID:23676205

  19. Implications of protein corona on physico-chemical and biological properties of magnetic nanoparticles.

    PubMed

    Yallapu, Murali M; Chauhan, Neeraj; Othman, Shadi F; Khalilzad-Sharghi, Vahid; Ebeling, Mara C; Khan, Sheema; Jaggi, Meena; Chauhan, Subhash C

    2015-04-01

    Interaction of serum proteins and nanoparticles leads to a nanoparticle-protein complex formation that defines the rational strategy for a clinically relevant formulation for drug delivery, hyperthermia, and magnetic resonance imaging (MRI) applications in cancer nanomedicine. Given this perspective, we have examined the pattern of human serum protein corona formation with our recently engineered magnetic nanoparticles (MNPs). The alteration in particle size, zeta potential, hemotoxicity, cellular uptake/cancer cells targeting potential, and MRI properties of the MNPs after formation of human serum (HS) protein corona were studied. Our results indicated no significant change in particle size of our MNPs upon incubation with 0.5-50 wt/v% human serum, while zeta potential of MNPs turned negative due to human serum adsorption. When incubated with an increased serum and particle concentration, apolipoprotein E was adsorbed on the surface of MNPs apart from serum albumin and transferrin. However, there was no significant primary or secondary structural alterations observed in serum proteins through Fourier transform infrared spectroscopy, X-ray diffraction, and circular dichroism. Hemolysis assay suggests almost no hemolysis at the tested concentrations (up to 1 mg/mL) for MNPs compared to the sodium dodecyl sulfate (positive control). Additionally, improved internalization and uptake of MNPs by C4-2B and Panc-1 cancer cells were observed upon incubation with human serum (HS). After serum protein adsorption to the surface of MNPs, the close vicinity within T1 (∼1.33-1.73 s) and T2 (∼12.35-13.43 ms) relaxation times suggest our MNPs retained inherent MRI potential even after biomolecular protein adsorption. All these superior clinical parameters potentially enable clinical translation and use of this formulation for next generation nanomedicine for drug delivery, cancer-targeting, imaging and theranostic applications. PMID:25678111

  20. Implications of protein corona on physico-chemical and biological properties of magnetic nanoparticles

    PubMed Central

    Yallapu, Murali M.; Chauhan, Neeraj; Othman, Shadi F.; Khalilzad-Sharghi, Vahid; Ebeling, Mara C.; Khan, Sheema; Jaggi, Meena; Chauhan, Subhash C.

    2015-01-01

    Interaction of serum proteins and nanoparticles leads to a nanoparticle-protein complex formation that defines the rational strategy for a clinically relevant formulation for drug delivery, hyperthermia, and magnetic resonance imaging (MRI) applications in cancer nanomedicine. Given this perspective, we have examined the pattern of human serum protein corona formation with our recently engineered magnetic nanoparticles (MNPs). The alteration in particle size, zeta potential, hemotoxicity, cellular uptake/cancer cells targeting potential, and MRI properties of the MNPs after formation of human serum (HS) protein corona were studied. Our results indicated no significant change in particle size of our MNPs upon incubation with 0.5-50 wt/v% human serum, while zeta potential of MNPs turned negative due to human serum adsorption. When incubated with an increased serum and particle concentration, apolipoprotein E was adsorbed on the surface of MNPs apart from serum albumin and transferrin. However, there was no significant primary or secondary structural alterations observed in serum proteins through Fourier transform infrared spectroscopy, X-ray diffraction, and circular dichroism. Hemolysis assay suggests almost no hemolysis at the tested concentrations (up to 1 mg/mL) for MNPs compared to the sodium dodecyl sulphate (positive control). Additionally, improved internalization and uptake of MNPs by C4-2B and Panc-1 cancer cells were observed upon incubation with human serum (HS). After serum protein adsorption to the surface of MNPs, the close vicinity within T1 (~1.33-1.73 s) and T2 (~ 12.35-13.43 ms) relaxation times suggest our MNPs retained inherent MRI potential even after biomolecular protein adsorption. All these superior clinical parameters potentially enable clinical translation and use of this formulation for next generation nanomedicine for drug delivery, cancer-targeting, imaging and theranostic applications. PMID:25678111

  1. Effects of residue 5-point mutation and N-terminus hydrophobic residues on temporin-SHc physicochemical and biological properties.

    PubMed

    Abbassi, Feten; Piesse, Christophe; Foulon, Thierry; Nicolas, Pierre; Ladram, Ali

    2014-09-01

    Temporin-SHc (FLSHIAGFLSNLFamide) first isolated from skin extraction of the Tunisian frog Pelophylax saharica, which shows potent antimicrobial activity against Gram-positive bacteria and is highly active against yeasts and fungi without hemolytic activity at antimicrobial concentrations. The peptide adopts well-defined α-helical conformation when bound to SDS micelles. In this study, we explored the effects of residue at position 5 and the N-terminus hydrophobic character on the hydrophilic/polar face of temp-SHc, on its biological activities (antimicrobial and hemolytic) and biophysical properties (hydrophobicity, amphipathicity and helicity). Antibacterial and hemolytic properties of temporin-SHc derivatives depend strongly on physicochemical properties. Therefore, slight decreasing amphipathicity together with hydrophobicity and helicity by the substitution Ile(5) → Leu decreased antimicrobial potency approximately twofold without changing of hemolytic activity. It is noteworthy that a conservative amino acid substitution decreases the antimicrobial activity, underlining the differences between Leu/Ile side chains insertion into the lipid bilayer. While the modification of N-terminal hydrophobic character by four residue inversion decreased amphipathicity (twofold) of (4-1)L5temp-SHc and resulted in an increase in antibacterial activity against E. coli, E. faecalis and C. parapsilosis of at least fourfold, its therapeutic potential is limited by its drastic increase of hemolysis (LC₅₀ = 2 μM). We found that the percentage of helicity of temp-SHc analog is directly correlated to its hemolytic activity. Last, the hydrophobic N-terminal character is an important determinant of antimicrobial activity. PMID:24842084

  2. Simulated-Physiological Loading Conditions Preserve Biological and Mechanical Properties of Caprine Lumbar Intervertebral Discs in Ex Vivo Culture

    PubMed Central

    Paul, Cornelis P. L.; Zuiderbaan, Hendrik A.; Zandieh Doulabi, Behrouz; van der Veen, Albert J.; van de Ven, Peter M.; Smit, Theo H.; Helder, Marco N.; van Royen, Barend J.; Mullender, Margriet G.

    2012-01-01

    Low-back pain (LBP) is a common medical complaint and associated with high societal costs. Degeneration of the intervertebral disc (IVD) is assumed to be an important causal factor of LBP. IVDs are continuously mechanically loaded and both positive and negative effects have been attributed to different loading conditions. In order to study mechanical loading effects, degeneration-associated processes and/or potential regenerative therapies in IVDs, it is imperative to maintain the IVDs' structural integrity. While in vivo models provide comprehensive insight in IVD biology, an accompanying organ culture model can focus on a single factor, such as loading and may serve as a prescreening model to reduce life animal testing. In the current study we examined the feasibility of organ culture of caprine lumbar discs, with the hypothesis that a simulated-physiological load will optimally preserve IVD properties. Lumbar caprine IVDs (n = 175) were cultured in a bioreactor up to 21 days either without load, low dynamic load (LDL), or with simulated-physiological load (SPL). IVD stiffness was calculated from measurements of IVD loading and displacement. IVD nucleus, inner- and outer annulus were assessed for cell viability, cell density and gene expression. The extracellular matrix (ECM) was analyzed for water, glycosaminoglycan and total collagen content. IVD biomechanical properties did not change significantly with loading conditions. With SPL, cell viability, cell density and gene expression were preserved up to 21 days. Both unloaded and LDL resulted in decreased cell viability, cell density and significant changes in gene expression, yet no differences in ECM content were observed in any group. In conclusion, simulated-physiological loading preserved the native properties of caprine IVDs during a 21-day culture period. The characterization of caprine IVD response to culture in the LDCS under SPL conditions paves the way for controlled analysis of degeneration- and

  3. Biological and Protective Properties of Immune Sera Directed to the Influenza Virus Neuraminidase

    PubMed Central

    Halbherr, Stefan J.; Ludersdorfer, Thomas H.; Ricklin, Meret; Locher, Samira; Berger Rentsch, Marianne; Summerfield, Artur

    2014-01-01

    ABSTRACT The envelope of influenza A viruses contains two large antigens, hemagglutinin (HA) and neuraminidase (NA). Conventional influenza virus vaccines induce neutralizing antibodies that are predominantly directed to the HA globular head, a domain that is subject to extensive antigenic drift. Antibodies directed to NA are induced at much lower levels, probably as a consequence of the immunodominance of the HA antigen. Although antibodies to NA may affect virus release by inhibiting the sialidase function of the glycoprotein, the antigen has been largely neglected in past vaccine design. In this study, we characterized the protective properties of monospecific immune sera that were generated by vaccination with recombinant RNA replicon particles encoding NA. These immune sera inhibited hemagglutination in an NA subtype-specific and HA subtype-independent manner and interfered with infection of MDCK cells. In addition, they inhibited the sialidase activities of various influenza viruses of the same and even different NA subtypes. With this, the anti-NA immune sera inhibited the spread of H5N1 highly pathogenic avian influenza virus and HA/NA-pseudotyped viruses in MDCK cells in a concentration-dependent manner. When chickens were immunized with NA recombinant replicon particles and subsequently infected with low-pathogenic avian influenza virus, inflammatory serum markers were significantly reduced and virus shedding was limited or eliminated. These findings suggest that NA antibodies can inhibit virus dissemination by interfering with both virus attachment and egress. Our results underline the potential of high-quality NA antibodies for controlling influenza virus replication and place emphasis on NA as a vaccine antigen. IMPORTANCE The neuraminidase of influenza A viruses is a sialidase that acts as a receptor-destroying enzyme facilitating the release of progeny virus from infected cells. Here, we demonstrate that monospecific anti-NA immune sera inhibited not

  4. A review of physical, chemical, and biological properties of fly ash and effects on agricultural ecosystems.

    PubMed

    el-Mogazi, D; Lisk, D J; Weinstein, L H

    1988-08-01

    Fly ash is the solid material which is carried away from the power plant boiler in the flue gas during coal combustion. The properties of fly ash may vary considerably according to several factors such as the geographical origin of the source coal, conditions during combustion, and sampling position within the power plant. A typical aggregate of fly ash from the combustion of eastern U.S. coals consists of spherical particles embedded in an amorphous matrix. Most fly ash particles are in the silt-sized range of 2-50 microns. The three major mineralogical matrices identified in fly ash are glass, mullite-quartz, and magnetic spinel. The major elemental constituents of fly ash are Si, Al, Fe, Ca, C, Mg, K, Na, S, Ti, P, and Mn. Nearly all naturally occurring elements can be found in fly ash in trace quantities. Certain trace elements, including As, Mo, Se, Cd, and Zn, are primarily associated with particle surfaces. The solubility of fly ash has been extensively investigated. Results of these investigations are largely dependent on factors specific to the extraction procedure. The most abundant species in fly ash extracts are inorganic ions derived from Ca, Na, Mg, K, Fe, S, and C. Boron is much more soluble than other trace elements in fly ash. The forms of some elements in fly ash extracts have been determined, but the species of most trace elements remain unidentified. Long-term leaching studies predict that fly ash will lose substantial amounts of soluble salts over time, but simulation models predict that the loss of trace elements from fly ash deposits through leaching will be very slow. The constituents of coal fly ash include small amounts of radioisotopes which do not appear to be hazardous. A complex mixture of organic compounds is also associated with fly ash particles. The organic compounds identified in fly ash extracts include known mutagens and carcinogens. Better methods for the extraction of organic compounds from fly ash particles must be developed

  5. Modification of the properties of biological membrane and its protection against oxidation by Actinidia arguta leaf extract.

    PubMed

    Cyboran, Sylwia; Oszmiański, Jan; Kleszczyńska, Halina

    2014-09-01

    The aim of the study was to determine the polyphenol composition and biological activity of an extract from the leaves of kiwi. Antioxidant and hemolytic activity of the extract were examined, as well as its effect on the physical properties of the erythrocyte membrane such as osmotic resistance, membrane fluidity, and packing order of its hydrophilic area. Antioxidant activity of the extract was determined in relation to the erythrocyte membrane oxidized with free radicals induced by UVB and UVC radiation and the compound AAPH. Chromatographic, spectrophotometric and fluorimetric methods were applied in the research. The obtained results showed that kiwi leaves are a rich source of polyphenolic substances, mainly catechins and their dimers, which do not induce red blood cell hemolysis but make them stronger and more resistant to changes in medium tonicity. Substances contained in the extract effectively protect erythrocyte membranes against oxidation induced by physicochemical factors, the effectiveness of the protection depending on the concentration and type of free radical inducer. In addition, the study showed that the kiwi extract increases fluidity of the erythrocyte membrane and causes an increase in packing disorder in the hydrophilic membrane area. The changes seem to be due to the presence of polyphenolic substances in the extract, mainly in the region of the polar heads of lipids, where they can form a barrier protecting the membrane against diffusion of free radicals to the membrane interior. The effects of the extract evidenced by the present research, in particular protection of the biological membrane against free radicals induced by physicochemical agents, make it a potential valuable food additive, to enrich it with polyphenolic compounds that inhibit lipid oxidation in food exposed to UVB radiation. Supplementing the organism with substances contained in kiwi leaves is expected to provide protection against many diseases that develop as a result

  6. Improvement of the titanium implant biological properties by coating with poly (ɛ-caprolactone)-based hybrid nanocomposites synthesized via sol-gel

    NASA Astrophysics Data System (ADS)

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando

    2016-05-01

    When bioactive coatings are applied to medical implants by means of sol-gel dip coating technique, the biological proprieties of the implant surface can be modified to match the properties of the surrounding tissues. In this study organo-inorganic nanocomposites materials were synthesized via sol-gel. They consisted of an inorganic zirconium-based and silica-based matrix, in which a biodegradable polymer (the poly-ɛ-caprolactone, PCL) was incorporated in different weight percentages. The synthesized materials, in sol phase, were used to dip-coat a substrate of commercially pure titanium grade 4 (CP Ti gr. 4) in order to improve its biological properties. A microstructural analysis of the obtained films was carried out by scanning electron microscopy (SEM) and attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR). Biological proprieties of the coated substrates were investigated by means of in vitro tests.

  7. The effect of anaesthetics on the properties of a lipid membrane in the biologically relevant phase: a computer simulation study.

    PubMed

    Fábián, Balázs; Darvas, Mária; Picaud, Sylvain; Sega, Marcello; Jedlovszky, Pál

    2015-06-14

    Molecular dynamics simulations of the fully hydrated neat dipalmitoylphosphatidylcholine (DPPC) membrane as well as DPPC membranes containing four different general anaesthetic molecules, namely chloroform, halothane, diethyl ether and enflurane, have been simulated at two different pressures, i.e., at 1 bar and 1000 bar, at the temperature of 310 K. At this temperature the model used in this study is known to be in the biologically most relevant liquid crystalline (Lα) phase. To find out which properties of the membrane might possibly be related to the molecular mechanism of anaesthesia, we have been looking for properties that change in the same way in the presence of any general anaesthetic molecule, and change in the opposite way by the increase of pressure. This way, we have ruled out the density distribution of various groups along the membrane normal axis, orientation of the lipid heads and tails, self-association of the anaesthetics, as well as the local order of the lipid tails as possible molecular reasons of anaesthesia. On the other hand, we have found that the molecular surface area, and hence also the molecular volume of the membrane, is increased by the presence of any anaesthetic molecule, and decreased by the pressure, in accordance with the more than half a century old critical volume hypothesis. We have also found that anaesthetic molecules prefer two different positions along the membrane normal axis, namely the middle of the membrane and the outer edge of the hydrocarbon region, close to the polar headgroups. The increase of pressure is found to decrease the former, and increase the latter preference, and hence it might also be related to the pressure reversal of anaesthesia. PMID:25975364

  8. Biological Soil Crusts from Coastal Dunes at the Baltic Sea: Cyanobacterial and Algal Biodiversity and Related Soil Properties.

    PubMed

    Schulz, Karoline; Mikhailyuk, Tatiana; Dreßler, Mirko; Leinweber, Peter; Karsten, Ulf

    2016-01-01

    Biological soil crusts (BSCs) are known as "ecosystem-engineers" that have important, multifunctional ecological roles in primary production, in nutrient and hydrological cycles, and in stabilization of soils. These communities, however, are almost unstudied in coastal dunes of the temperate zone. Hence, for the first time, the biodiversity of cyanobacterial and algal dominated BSCs collected in five dunes from the southern Baltic Sea coast on the islands Rügen and Usedom (Germany) was investigated in connection with physicochemical soil parameters. The species composition of cyanobacteria and algae was identified with direct determination of crust subsamples, cultural methods, and diatom slides. To investigate the influence of soil properties on species composition, the texture, pH, electrical conductivity, carbonate content, total contents of carbon, nitrogen, phosphorus, and the bioavailable phosphorus-fraction (PO4 (3-)) were analyzed in adjacent BSC-free surface soils at each study site. The data indicate that BSCs in coastal dunes of the southern Baltic Sea represent an ecologically important vegetation form with a surprisingly high site-specific diversity of 19 cyanobacteria, 51 non-diatom algae, and 55 diatoms. All dominant species of the genera Coleofasciculus, Lyngbya, Microcoleus, Nostoc, Hydrocoryne, Leptolyngbya, Klebsormidium, and Lobochlamys are typical aero-terrestrial cyanobacteria and algae, respectively. This first study of coastal sand dunes in the Baltic region provides compelling evidence that here the BSCs were dominated by cyanobacteria, algae, or a mixture of both. Among the physicochemical soil properties, the total phosphorus content of the BSC-free sand was the only factor that significantly influenced the cyanobacterial and algal community structure of BSCs in coastal dunes. PMID:26507846

  9. The effect of strontium incorporation into CaSiO3 ceramics on their physical and biological properties.

    PubMed

    Wu, Chengtie; Ramaswamy, Yogambha; Kwik, Danielle; Zreiqat, Hala

    2007-07-01

    CaSiO3 ceramics have been regarded as a potential bioactive material for bone regeneration. Strontium (Sr) as a trace element in human body has been found to have beneficial effects on bone formation. The aim of this study was to incorporate Sr into CaSiO3 bioactive ceramics and to investigate their effect(s) on phase transition, sintering property, apatite-formation ability, ionic dissolution, and human bone-derived cells (HBDC) proliferation. Sr containing CaSiO3 (Sr-CaSiO3) ceramics at various concentrations (0-10% Sr) were prepared. The incorporation of Sr into CaSiO3 promoted the phase transition from beta to alpha-CaSiO3 and enhanced ceramic densification but did not alter the mechanism and ability of apatite formation in SBF. The ionic dissolution rate of the Sr-CaSiO3 decreased compared to the CaSiO3. The addition of Sr decreased pH value in SBF. The effect of Sr-CaSiO3 extracts, carried out according to the International Standard Organization, on HBDC proliferation was evaluated. At high extract concentration (100 and 200 mg/mL), CaSiO3 was found to stimulate HBDC proliferation, however, the incorporation of Sr into CaSiO3 stimulated HBDC proliferation even at low extract concentration (ranging from 12.5, 25 to 50 mg/mL). Our results indicate that Sr-CaSiO3 ceramics improved the physical and biological properties of the pure CaSiO3 ceramics. PMID:17445881

  10. Effect of Hyaluronic Acid Incorporation Method on the Stability and Biological Properties of Polyurethane-Hyaluronic Acid Biomaterials

    PubMed Central

    Ruiz, Amaliris; Rathnam, Kashmila R.; Masters, Kristyn S.

    2014-01-01

    The high failure rate of small diameter vascular grafts continues to drive the development of new materials and modification strategies that address this clinical problem, with biomolecule incorporation typically achieved via surface-based modification of various biomaterials. In this work, we examined whether the method of biomolecule incorporation (i.e., bulk vs. surface modification) into a polyurethane (PU) polymer impacted biomaterial performance in the context of vascular applications. Specifically, hyaluronic acid (HA) was incorporated into a poly(ether urethane) via bulk copolymerization or covalent surface tethering, and the resulting PU-HA materials characterized with respect to both physical and biological properties. Modification of PU with HA by either surface or bulk methods yielded materials that, when tested under static conditions, possessed no significant differences in their ability to resist protein adsorption, platelet adhesion, and bacterial adhesion, while supporting endothelial cell culture. However, only bulk-modified PU-HA materials were able to fully retain these characteristics following material exposure to flow, demonstrating a superior ability to retain the incorporated HA and minimize enzymatic degradation, protein adsorption, platelet adhesion, and bacterial adhesion. Thus, despite bulk methods rarely being implemented in the context of biomolecule attachment, these results demonstrate improved performance of PU-HA upon bulk, rather than surface, incorporation of HA. Although explored only in the context of PU-HA, the findings revealed by these experiments have broader implications for the design and evaluation of vascular graft modification strategies. PMID:24276670

  11. Synthesis, biological evaluation, and physicochemical property assessment of 4-substituted 2-phenylaminoquinazolines as Mer tyrosine kinase inhibitors.

    PubMed

    Wang, Sheng-Biao; Cui, Mu-Tian; Wang, Xiao-Feng; Ohkoshi, Emika; Goto, Masuo; Yang, De-Xuan; Li, Linna; Yuan, Shoujun; Morris-Natschke, Susan L; Lee, Kuo-Hsiung; Xie, Lan

    2016-07-01

    Current results identified 4-substituted 2-phenylaminoquinazoline compounds as novel Mer tyrosine kinase (Mer TK) inhibitors with a new scaffold. Twenty-one 2,4-disubstituted quinazolines (series 4-7) were designed, synthesized, and evaluated against Mer TK and a panel of human tumor cell lines aimed at exploring new Mer TK inhibitors as novel potential antitumor agents. A new lead, 4b, was discovered with a good balance between high potency (IC50 0.68μM) in the Mer TK assay and antiproliferative activity against MV4-11 (GI50 8.54μM), as well as other human tumor cell lines (GI50<20μM), and a desirable druglike property profile with low logP value (2.54) and high aqueous solubility (95.6μg/mL). Molecular modeling elucidated an expected binding mode of 4b with Mer TK and necessary interactions between them, thus supporting the hypothesis that Mer TK might be a biologic target of this kind of new active compound. PMID:27238842

  12. Mesenchymal stem cells derived from Wharton's Jelly of the umbilical cord: biological properties and emerging clinical applications.

    PubMed

    Batsali, Aristea K; Kastrinaki, Maria-Christina; Papadaki, Helen A; Pontikoglou, Charalampos

    2013-03-01

    In recent years there seems to be an unbounded interest concerning mesenchymal stem cells (MSCs). This is mainly attributed to their exciting characteristics including long-term ex vivo proliferation, multilineage potential and immunomodulatory properties. In this regard MSCs emerge as attractive candidates for various therapeutic applications. MSCs were originally isolated from the bone marrow (BM) and this population is still considered as the gold standard for MSC applications. Nevertheless the BM has several limitations as source of MSCs, including MSC low frequency in this compartment, the painful isolation procedure and the decline in MSC characteristics with donor's age. Thus, there is accumulating interest in identifying alternative sources for MSCs. To this end MSCs obtained from the Wharton's Jelly (WJ) of umbilical cords (UC) have gained much attention over the last years since they can be easily isolated, without any ethical concerns, from a tissue which is discarded after birth. Furthermore WJ-derived MSCs represent a more primitive population than their adult counterparts, opening new perspectives for cell-based therapies. In this review we will at first give an overview of the biology of WJ-derived UC-MSCs. Then their potential application for the treatment of cancer and immune mediated disorders, such graft versus host disease (GVHD) and systemic lupus erythematosus (SLE) will be discussed, and finally their putative role as feeder layer for ex vivo hematopoietic stem cell (HSC) expansion will be pointed out. PMID:23279098

  13. Two splicing variants of a new inhibitor of apoptosis gene with different biological properties and tissue distribution pattern.

    PubMed

    Ashhab, Y; Alian, A; Polliack, A; Panet, A; Ben Yehuda, D

    2001-04-20

    Using homology searches, we identified a novel human inhibitor of apoptosis (IAP) gene. This gene has two splicing variants that contain open reading frames of 298 and 280 amino acids and both contained a single copy of baculovirus IAP repeat (BIR) and RING domain. We refer here to the longer and shorter variants as Livin alpha and beta, respectively. Semiquantitative reverse transcriptase-polymerase chain reaction demonstrated a tissue-specific and non-correlated expression pattern in both adult and fetal tissues. Both mRNA variants were detected in various transformed cell lines. Despite their very close similarity, the two isoforms have different antiapoptotic properties. Both isoforms have a significant antiapoptotic activity in the Jurkat T cell line after triggering apoptosis via tumor necrosis factor and CD95 receptors. The Livin alpha but not beta protects cells from apoptosis induced by staurosporine, but in contrast, apoptosis initiated by etoposide was blocked only by the beta isoform. This difference in biological activities may indicate the presence of critical amino acids outside the BIR and RING domains. These functional and tissue distribution differences of Livin alpha and beta suggest that Livin may play a complex role in the regulation of apoptosis. PMID:11322947

  14. Biological properties of titanium implants covered with hydroxyapatite and zirconia layers by pulsed laser: In vitro study

    NASA Astrophysics Data System (ADS)

    Seydlova, Michaela; Teuberova, Zuzana; Dostalova, Tatjana; Dvorankova, Barbora; Smetana, Karel; Jelinek, Miroslav; Kocourek, Tomas; Mroz, Waldemar

    2006-01-01

    The biological and physical properties of dental implants coated by the sandwich technique with a thin layer of hydroxyapatite and an interlayer of zirconia were evaluated. The implant samples were covered by pulsed laser deposition. The aim of our study is to evaluate the cytotoxicity and the surface characteristics of the titanium targets modified with zirconia and hydroxyapatite. The titanium substrates were analyzed physically by x-ray diffraction and scanning electron microscopy. We used a direct test of cytotoxicity to compare the prepared samples with other reference materials. No changes in the morphology or the proliferation rate of the cells used were found in the presence of the modified titanium targets. The adhesion, proliferation, and fibronectin expressions of human fibroblasts were also evaluated on the surface of the modified titanium targets. The results show that the modified titanium samples are at least as attractive as the tissue grade polystyrene in promoting fibroblasts' adhesion and proliferation. The results show adhesion and cell proliferation, which in turn implies that the studied material is not cytotoxic and is suitable for cell colonization. Titanium modified with zirconia and hydroxyapatite can be beneficially employed in oral bone surgery.

  15. Caffeine-based gold(I) N-heterocyclic carbenes as possible anticancer agents: synthesis and biological properties.

    PubMed

    Bertrand, Benoît; Stefan, Loic; Pirrotta, Marc; Monchaud, David; Bodio, Ewen; Richard, Philippe; Le Gendre, Pierre; Warmerdam, Elena; de Jager, Marina H; Groothuis, Geny M M; Picquet, Michel; Casini, Angela

    2014-02-17

    A new series of gold(I) N-heterocyclic carbene (NHC) complexes based on xanthine ligands have been synthesized and characterized by mass spectrometry, NMR, and X-ray diffraction. The compounds have been tested for their antiproliferative properties in human cancer cells and nontumorigenic cells in vitro, as well as for their toxicity in healthy tissues ex vivo. The bis-carbene complex [Au(caffein-2-ylidene)2][BF4] (complex 4) appeared to be selective for human ovarian cancer cell lines and poorly toxic in healthy organs. To gain preliminary insights into their actual mechanism of action, two biologically relevant in cellulo targets were studied, namely, DNA (more precisely a higher-order DNA structure termed G-quadruplex DNA that plays key roles in oncogenetic regulation) and a pivotal enzyme of the DNA damage response (DDR) machinery (poly-(adenosine diphosphate (ADP)-ribose) polymerase 1 (PARP-1), strongly involved in the cancer resistance mechanism). Our results indicate that complex 4 acts as an efficient and selective G-quadruplex ligand while being a modest PARP-1 inhibitor (i.e., poor DDR impairing agent) and thus provide preliminary insights into the molecular mechanism that underlies its antiproliferative behavior. PMID:24499428

  16. The influence of poly(ethylene glycol) ether tetrasuccinimidyl glutarate on the structural, physical, and biological properties of collagen fibers.

    PubMed

    Sanami, Mohammad; Sweeney, India; Shtein, Zvi; Meirovich, Sigal; Sorushanova, Anna; Mullen, Anne Maria; Miraftab, Mohsen; Shoseyov, Oded; O'Dowd, Colm; Pandit, Abhay; Zeugolis, Dimitrios I

    2016-07-01

    Various chemical, natural, or synthetic in origin, crosslinking methods have been proposed over the years to stabilise collagen fibers. However, an optimal method has yet to be identified. Herein, we ventured to assess the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate, as opposed to glutaraldehyde (GTA), genipin and carbodiimide, on the structural, physical and biological properties of collagen fibers. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate induced an intermedium surface smoothness, denaturation temperature and swelling. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers had significantly higher stress at break values than the carbodiimide fibers, but significantly lower than the GTA and genipin fibers. With respect to strain at break, no significant difference was observed among the crosslinking treatments. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers exhibited significantly higher cell metabolic activity and DNA concentration that all other crosslinking treatments, promoted consistently cellular elongation along the longitudinal fiber axis and by day 7 they were completely covered by cells. Collectively, this work clearly demonstrates the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate as collagen crosslinker. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 914-922, 2016. PMID:25952265

  17. Biological and immunological properties of the venom of Bothrops alcatraz, an endemic species of pitviper from Brazil.

    PubMed

    Furtado, M F D

    2005-06-01

    Bothrops alcatraz is a new pitviper species derived from the Bothrops jararaca group, whose natural habitat is situated in Alcatrazes Archipelago, a group of marine islands near São Paulo State coast in Brazil. Herein, the biological and biochemical properties of venoms of four adult specimens of B. alcatraz were examined comparatively to a reference pool of Bothrops jararaca venom. Both venoms showed similar activities and electrophoretic patterns, but B. alcatraz venom showed three protein bands of molecular masses of 97, 80 and 38 kDa that were not present in B. jararaca reference venom. The i.p. median lethal dose of B. alcatraz venom ranged from 5.1 to 6.6 mg/kg, while it was 1.5 mg/kg for B. jararaca venom. The minimum hemorrhagic dose of B. jararaca venom was 0.63, whereas 2.28 mug/mouse for B. alcatraz venom. In contrast, B. alcatraz venom was more potent in regard to procoagulant and proteolytic activities. These differences were supported by western blotting and neutralization tests, employing commercial bothropic antivenom, which showed that hemorrhagic and lethal activities of B. alcatraz venom were less effectively inhibited than B. jararaca venom. Such results evidence that B. alcatraz shows quantitative and qualitative differences in venom composition in comparison with its B. jararaca relatives, which might represent an optimization of venom towards a specialized diet. PMID:16002343

  18. Chemical Stability and Biological Properties of Plasma-Sprayed CaO-SiO2-ZrO2 Coatings

    NASA Astrophysics Data System (ADS)

    Liang, Ying; Xie, Youtao; Ji, Heng; Huang, Liping; Zheng, Xuebin

    2010-12-01

    In this work, calcia-stabilized zirconia powders were coated by silica derived from tetraethoxysilane (TEOS) hydrolysis. After calcining at 1400 °C, decalcification of calcia-stabilized zirconia by silica occurred and powders composed of Ca2SiO4, ZrO2, and CaZrO3 were prepared. We produced three kinds of powders with different Ca2SiO4 contents [20 wt.% (denoted as CZS2), 40 wt.% (denoted as CZS4), and 60 wt.% (denoted as CZS6)]. The obtained powders were sprayed onto Ti-6Al-4V substrates using atmospheric plasma spraying. The microstructure of the powders and coatings were analyzed. The dissolution rates of the coatings were assessed by monitoring the ions release and mass losses after immersion in Tris-HCl buffer solution. Results showed that the chemical stability of the coatings were significantly improved compared with pure calcium silicate coatings, and increased with the increase of Zr contents. The CZS4 coating showed not only good apatite-formation ability in simulated body fluid, but also well attachment and proliferation capability for the canine bone marrow stem cells. Results presented here indicate that plasma-sprayed CZS4 coating has medium dissolution rate and good biological properties, suggesting its potential use as bone implants.

  19. [The information value of the biological properties of the causative agent in the prognosis of the duration of the course of suppurative inflammatory diseases of staphylococcal etiology].

    PubMed

    Deriabin, D G; Kurlaev, P P

    1999-01-01

    The informative value of biological characteristics of Staphylococcus aureus reflecting the ability of microbes to inactivate certain factors of natural resistance (lysozyme, complement, immunoglobulins, bactericidal component of interferon) was established in determining the duration of the caused by them pyo-inflammatory diseases such as postinfection abscesses, lactation mastitis. On this basis the heterogeneous successive procedure of pattern recognition was used to develop algorithms allowing prognosis of the duration of pyo-inflammatory diseases of staphylococcal etiology in 84.6-94.4% of the patients after the quantitative and qualitative assessment of the biological properties of the pathogen with not less than 90% reliability. PMID:10491834

  20. Recombinant Paracoccin Reproduces the Biological Properties of the Native Protein and Induces Protective Th1 Immunity against Paracoccidioides brasiliensis Infection

    PubMed Central

    Alegre, Ana Claudia Paiva; Oliveira, Aline Ferreira; Dos Reis Almeida, Fausto Bruno; Roque-Barreira, Maria Cristina; Hanna, Ebert Seixas

    2014-01-01

    Background Paracoccin is a dual-function protein of the yeast Paracoccidioides brasiliensis that has lectin properties and N-acetylglucosaminidase activities. Proteomic analysis of a paracoccin preparation from P. brasiliensis revealed that the sequence matched that of the hypothetical protein encoded by PADG-3347 of isolate Pb-18, with a polypeptide sequence similar to the family 18 endochitinases. These endochitinases are multi-functional proteins, with distinct lectin and enzymatic domains. Methodology/principal findings The multi-exon assembly and the largest exon of the predicted ORF (PADG-3347), was cloned and expressed in Escherichia coli cells, and the features of the recombinant proteins were compared to those of the native paracoccin. The multi-exon protein was also used for protection assays in a mouse model of paracoccidioidomycosis. Conclusions/Significance Our results showed that the recombinant protein reproduced the biological properties described for the native protein—including binding to laminin in a manner that is dependent on carbohydrate recognition—showed N-acetylglucosaminidase activity, and stimulated murine peritoneal macrophages to produce high levels of TNF-α and nitric oxide. Considering the immunomodulatory potential of glycan-binding proteins, we also investigated whether prophylactic administration of recombinant paracoccin affected the course of experimental paracoccidioidomycosis in mice. In comparison to animals injected with vehicle (controls), mice treated with recombinant paracoccin displayed lower pulmonary fungal burdens and reduced pulmonary granulomas. These protective effects were associated with augmented pulmonary levels of IL-12 and IFN-γ. We also observed that injection of paracoccin three days before challenge was the most efficient administration protocol, as the induced Th1 immunity was balanced by high levels of pulmonary IL-10, which may prevent the tissue damage caused by exacerbated inflammation. The

  1. The in vitro biological properties of Mg-Zn-Sr alloy and superiority for preparation of biodegradable intestinal anastomosis rings

    PubMed Central

    Liu, Ling; Li, Nianfeng; Lei, Ting; Li, Kaimo; Zhang, Yangde

    2014-01-01

    Background Magnesium (Mg) alloy is a metal-based biodegradable material that has received increasing attention in the field of clinical surgery, but it is currently seldom used in intestinal anastomosis. This study was conducted to comprehensively assess a ternary magnesium (Mg)-zinc (Zn)-strontium (Sr) alloy’s biological superiorities as a preparation material for intestinal anastomosis ring. Material/Methods Mouse L-929 fibroblasts were cultured with Mg-Zn-Sr alloy extract and compared with both positive (0.64% phenol) and negative (original broth culture) controls. The cell morphology of different groups was examined using microscopy, and a cytotoxicity assessment was performed. Fresh anticoagulated human blood was mixed with Mg-Zn-Sr alloy extract and compared with both positive (distilled water) and negative (normal saline) controls. The absorbance of each sample at 570 nm was used to calculate the Mg-Zn-Sr alloy hemolysis ratio in order to test the Mg alloy’s blood compatibility. Bacterial cultures of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were added to Mg-Zn-Sr alloy block samples and compared with positive (Ceftazidime), negative (316LSS stainless steel), and blank controls. The broth cultures were sampled to compare their bacterial colony counts so as to evaluate the antibacterial properties of the Mg-Zn-Sr alloy. The Mg-Zn-Sr alloy was surface-coated with a layer of poly(lactic-co-glycolic acid) carrying everolimus. The surface morphology and degradability of the coating were examined so as to demonstrate feasibility of coating, which can release the drug evenly. Results The experiments proved that Mg-Zn-Sr alloy has good biocompatible, antibacterial, and drug-loaded coating performances, which are lacking in existing intestinal anastomosis devices/materials. Conclusions The Mg-Zn-Sr alloy increases biocompatibility, and yields a safer and better therapeutic effect; therefore, it is a novel biomaterial that is feasible for

  2. Design, synthesis, linear and nonlinear photophysical properties and biological imaging application of a novel Λ-type pyrimidine-based thiophene derivative

    NASA Astrophysics Data System (ADS)

    Zhang, Qiong; Luo, Junshan; Ye, Lili; Wang, Hui; Huang, Bei; Zhang, Jun; Wu, Jieying; Zhang, Shengyi; Tian, Yupeng

    2014-09-01

    A novel D-π-A-π-D type thiophene pyrimidine derivative, 2,2‧-thiophene-4, 6-bis (4-N,N-diethylbenzene ethenyl) pyrimidine (L), was designed, synthesized via Knoevenagel and Suzuki coupling reactions, and fully characterized. The results of X-ray diffraction analysis revealed that single crystal of L belongs to P212121 non-centrosymmetric space group, and the whole molecular skeleton exhibits a good coplanarity. Systematic photophysical properties were investigated for L. The connections between the properties and structure were explained relying on theoretical calculation. The thiophene pyrimidine derivative shows strong third-order nonlinear optical response and large two-photon absorption (2PA) cross section in high polar solvents. Finally, preliminary exploration in biological imaging also has been carried out, it shows a good biological application prospect.

  3. Hydration Structures and Thermodynamic Properties of Cationized Biologically Relevant Molecules, M+(Indole)(H2O)n (M = Na, K; n = 3-6)

    NASA Astrophysics Data System (ADS)

    Ke, Haochen; Lisy, James

    2015-03-01

    The balance between various noncovalent interactions plays a key role in determining the hydration structures and thermodynamic properties of biologically relevant molecules in biological mediums. Such properties of biologically relevant molecules are closely related to their often unique biological functionalities. The indole moiety is a basic functional group of many important neurotransmitters and hormones and has been used as tractable model for more complex biomolecules. The cationized indole water cluster is a perfect system for the quantitative and systematic study of the competition and cooperation of noncovalent interactions, as electrostatic interactions can be adjusted by introducing different monovalent cations and hydrogen bonding interactions can be adjusted by varying the level of hydration. IRPD spectra with isotopic (H/D) analysis helped unravel the overlapping N-H and O-H stretching modes, a major challenge of earlier studies. Thermodynamic analysis using relative Gibbs free energies, for energy ordering, together with spectral analysis provided unambiguous assignment of spectral features and structural configurations. A systematic hydration model with an in-depth account of noncovalent interactions is presented.

  4. Biological Role of Anions (Sulfate, Nitrate , Oxalate and Acetate) on the Antibacterial Properties of Cobalt (II) and Nickel(II) Complexes With Pyrazinedicarboxaimide Derived, Furanyl and Thienyl Compounds.

    PubMed

    Chohan, Z H; Praveen, M

    1999-01-01

    A number of biologically active complexes of cobalt(II) and nickel(II) with pyrazinedicarboxaimido derived thienyl and furanyl compounds having the same metal ion but different anions such as sulphate, nitrate, oxalate and acetate have been synthesized and characterized on the basis of their physical, spectral and analytical data. In order to evaluate the role of anions on their antibacterial properties, these ligands and their synthesized metal complexes with various anions have been screened against bacterial species Escherichia coil,Pseudomonas aeruginosa and Staphylococcus aureus. The title studies have proved a definitive role of anions in increasing the antibacterial properties. PMID:18475887

  5. Biological Role of Anions (Sulfate, Nitrate , Oxalate and Acetate) on the Antibacterial Properties of Cobalt (II) and Nickel(II) Complexes With Pyrazinedicarboxaimide Derived, Furanyl and Thienyl Compounds

    PubMed Central

    Praveen, M.

    1999-01-01

    A number of biologically active complexes of cobalt(II) and nickel(II) with pyrazinedicarboxaimido derived thienyl and furanyl compounds having the same metal ion but different anions such as sulphate, nitrate, oxalate and acetate have been synthesized and characterized on the basis of their physical, spectral and analytical data. In order to evaluate the role of anions on their antibacterial properties, these ligands and their synthesized metal complexes with various anions have been screened against bacterial species Escherichia coil,Pseudomonas aeruginosa and Staphylococcus aureus. The title studies have proved a definitive role of anions in increasing the antibacterial properties. PMID:18475887

  6. Biological and physical properties of a model calcitonin containing a glutamate residue interrupting the hydrophobic face of the idealized amphiphilic alpha-helical region.

    PubMed Central

    Green, F R; Lynch, B; Kaiser, E T

    1987-01-01

    2A new calcitonin analogue, model calcitonin III (MCt-III), has been synthesized, and its biological and physical characteristics have been studied. This analogue has an idealized alpha-helix from residue 8-22 with glutamate at position 15 interrupting an otherwise continuous surface of aliphatic side chains (those of leucine residues) on the hydrophobic face of the helix. MCt-III differs from a previous model, MCt-II, only by the substitution Leu15----Glu and is here compared with salmon calcitonin I (sCt-I) and MCt-II to elucidate further the role of the putative amphiphilic alpha-helix in determining biological and physical properties of the hormone. MCt-III shows physical properties intermediate between those of sCt-I and MCt-II, demonstrating the influence of appropriately positioned single residues on properties of amphiphilic structures. In our two biological assays, a brain-binding assay and an in vivo hypocalcemic assay, MCt-III reproduces the sigmoidal dose-response curves of sCt-I; this contrasts with the behavior of MCt-II, which demonstrated unusual dose-response curves in these two assays. MCt-III is almost three times more potent than sCt-I in our hypocalcemic assay; this activity groups MCt-III among the most potent known analogues of sCt-I. PMID:2825187

  7. Effects of increasing hydrophobicity on the physical-chemical and biological properties of a class A amphipathic helical peptide.

    PubMed

    Datta, G; Chaddha, M; Hama, S; Navab, M; Fogelman, A M; Garber, D W; Mishra, V K; Epand, R M; Epand, R F; Lund-Katz, S; Phillips, M C; Segrest, J P; Anantharamaiah, G M

    2001-07-01

    We have recently shown that a class A amphipathic peptide 5F with increased amphipathicity protected mice from diet-induced atherosclerosis (Garber et al. J. Lipid Res. 2001. 42: 545-552). We have now examined the effects of increasing the hydrophobicity of a series of homologous class A amphipathic peptides, including 5F, on physical and functional properties related to atherosclerosis inhibition by systematically replacing existing nonpolar amino acids with phenylalanine. The peptides, based on the sequence Ac-D-W-L-K-A-F-Y-D-K-V-A-E-K-L-K-E-A-F-NH(2) (Ac-18A-NH(2) or 2F) were: 3F(3)(Ac-F(3)18A-NH(2)), 3F(14)(Ac-F(14)18A-NH(2)), 4F(Ac-F(3,14)18A-NH(2)), 5F(Ac-F(11,14,17) 18A-NH(2)), 6F(Ac-F(10,11,14,17)18A-NH(2)), and 7F(Ac-F(3,10,11,14,17) 18A-NH(2)). Measurements of aqueous solubility, HPLC retention time, exclusion pressure for penetration into an egg phosphatidylcholine (EPC) monolayer, and rates of EPC solubilization revealed an abrupt increase in the hydrophobicity between peptides 4F and 5F; this was accompanied by increased ability to associate with phospholipids. The peptides 6F and 7F were less effective, indicating a limit to increased hydrophobicity for promoting lipid interaction in these peptides. Despite this marked increase in lipid affinity, these peptides were less effective than apoA-I in activating the plasma enzyme, lecithin:cholesterol acyltransferase, with 5F activating LCAT the best (80% of apoA-I). Peptides 4F, 5F, and 6F were equally potent in inhibiting LDL-induced monocyte chemotactic activity. These studies suggest that an appropriate balance between peptide-peptide and peptide-lipid interactions is required for optimal biological activity of amphipathic peptides. These studies provide a rationale for the design of small apoA-I-mimetics with increased potency for atherosclerosis inhibition. PMID:11441137

  8. Chemotactic cytokines and inflammation. Biological properties of the lymphocyte and monocyte chemotactic factors ELCF, MCAF and IL-8.

    PubMed

    Zachariae, C O

    1993-01-01

    This thesis discusses the phenotypic characteristics of different inflammatory dermatological diseases and sets this into context with the specific chemotactic ability of different cytokines. It further discusses the biological properties of different chemotactic cytokines and their relevance in certain inflammatory diseases. The term chemotaxis was introduced in 1884 by Pfeffer, who described it as directional migration of leukocytes along a gradient. Regular studies of chemotaxis were, however, not possible until 1962 when Boyden developed the chemotaxis chamber technique. This test has since then been improved, and it is now possible to define and characterize chemoattractants and examine the special chemotactic behavior of leukocytes. We investigated T lymphocyte responses towards different chemoattractants using a modified Boyden chamber technique and found that approximately 50% of normal individuals have cells which respond whereas T-cells from the remaining persons did not respond. We therefore chose human T lymphocytic cell lines as target cells for chemotaxis screening to avoid inter-individual variations among donors. T lymphocytic infiltrates dominated by CD4+, CD45R0+ memory T cells are characteristic for many dermatological inflammatory diseases. We have therefore performed experiments to evaluate whether an earlier described epidermal lymphocyte chemotactic factor (ELCF) from skin overlying a tuberculin skin reaction in addition with other cytokines specifically attracts different subsets of lymphocytes. ELCF which probably reflects a mixture of different epidermal T lymphocyte chemotactic factors rather than a single factor was shown to specifically attract CD4+, CD45R0+ T lymphocytes in contrast to fMLP, IL-8, C5a and LTB4, which induced equal chemotaxis for both CD4+ and CD8+ T lymphocytes. A newly described inhibitory cytokine IL-10 selectively attracted the CD8+ subpopulation of T lymphocytes, and it is suggested that IL-10 could be an important

  9. INTERACTIONS BETWEEN PHOTOCHEMICAL AND MICROBIAL DECOMPOSITION IN MODIFYING THE BIOLOGICAL AVAILABILITY AND OPTICAL PROPERTIES OF ESTUARINE DISSOLVED ORGANIC MATTER

    EPA Science Inventory

    Direct photodecomposition and photochemically-mediated bacterial degradation (via photochemical modification of otherwise refractory DOM into biologically labile forms) provide
    important pathways for the loss of dissolved organic matter in coastal waters. Here we report
    lab...

  10. Calculated absorption and scattering properties of gold nanoparticles of different size, shape, and composition: applications in biological imaging and biomedicine.

    PubMed

    Jain, Prashant K; Lee, Kyeong Seok; El-Sayed, Ivan H; El-Sayed, Mostafa A

    2006-04-13

    The selection of nanoparticles for achieving efficient contrast for biological and cell imaging applications, as well as for photothermal therapeutic applications, is based on the optical properties of the nanoparticles. We use Mie theory and discrete dipole approximation method to calculate absorption and scattering efficiencies and optical resonance wavelengths for three commonly used classes of nanoparticles: gold nanospheres, silica-gold nanoshells, and gold nanorods. The calculated spectra clearly reflect the well-known dependence of nanoparticle optical properties viz. the resonance wavelength, the extinction cross-section, and the ratio of scattering to absorption, on the nanoparticle dimensions. A systematic quantitative study of the various trends is presented. By increasing the size of gold nanospheres from 20 to 80 nm, the magnitude of extinction as well as the relative contribution of scattering to the extinction rapidly increases. Gold nanospheres in the size range commonly employed ( approximately 40 nm) show an absorption cross-section 5 orders higher than conventional absorbing dyes, while the magnitude of light scattering by 80-nm gold nanospheres is 5 orders higher than the light emission from strongly fluorescing dyes. The variation in the plasmon wavelength maximum of nanospheres, i.e., from approximately 520 to 550 nm, is however too limited to be useful for in vivo applications. Gold nanoshells are found to have optical cross-sections comparable to and even higher than the nanospheres. Additionally, their optical resonances lie favorably in the near-infrared region. The resonance wavelength can be rapidly increased by either increasing the total nanoshell size or increasing the ratio of the core-to-shell radius. The total extinction of nanoshells shows a linear dependence on their total size, however, it is independent of the core/shell radius ratio. The relative scattering contribution to the extinction can be rapidly increased by increasing

  11. The use of principal component analysis in studying physical, chemical and biological soil properties in southern caspian forests (North of Iran).

    PubMed

    Kooch, Yahya; Jalilvand, Hamid; Bahmanyar, Mohammad Ali; Pormajidian, Mohammad Reza

    2008-02-01

    This research was conducted in Khanikan forests located in lowland of Mazandaran province (North of Iran). Eighteen profiles were dug and several chemical, physical and biological soil properties were investigated. The soil properties evaluated were soil pH, bulk density, saturation moisture content, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, calcium carbonate content, number and biomass of earthworms, litter carbon and litter nitrogen. Principal Component Analysis (PCA) was used to identify the variation of soil properties. PCA, a technique which reduces the dimensionality of multivariate data by removing Interco relations among variables, has a number of useful applications in forest researches. The results showed significant relationships between some soil factors with PC1 and PC2 axes, also, among different soil factors, the distribution of forest types was most strongly controlled with some soil characteristics such as acidity, bulk density, texture, phosphorous, organic carbon, total nitrogen and cation exchangeable capacity. PMID:18817157

  12. On the structural affinity of macromolecules with different biological properties: molecular dynamics simulations of a series of TEM-1 mutants.

    PubMed

    Giampaolo, Alessia Di; Mazza, Fernando; Daidone, Isabella; Amicosante, Gianfranco; Perilli, Mariagrazia; Aschi, Massimiliano

    2013-07-12

    Molecular Dynamics simulations have been carried out in order to provide a molecular rationalization of the biological and thermodynamic differences observed for a class of TEM β-lactamases. In particular we have considered the TEM-1(wt), the single point mutants TEM-40 and TEM-19 representative of IRT and ESBL classes respectively, and TEM-1 mutant M182T, TEM-32 and TEM-20 which differ from the first three for the additional of M182T mutation. Results indicate that most of the thermodynamic, and probably biological behaviour of these systems arise from subtle effects which, starting from the alterations of the local interactions, produce drastic modifications of the conformational space spanned by the enzymes. The present study suggests that systems showing essentially the same secondary and tertiary structure may differentiate their chemical-biological activity essentially (and probably exclusively) on the basis of the thermal fluctuations occurring in their physiological environment. PMID:23770365

  13. To be or not IP? Exploring limits within patent law for the constitutionalization of intellectual property rights and the governance of synthetic biology in human health.

    PubMed

    Schneider, Ingrid

    2012-01-01

    The article explores limits within patent law for the constitutionalization of Intellectual Property Rights and the governance of synthetic biology in human health. To this end, it starts by explaining the inherent rationales of two fundamental limits within European patent law, namely (1) the boundary between discovery and invention (Art. 52 EPC); (2) the ordre public and public policy clause (Art. 53 (a) EPC). Both these exclusions from patent eligibility bear a normative function but rely on opposing inherent logics, functions, and regulatory aims. While in the first type of logics, "enabling access for all" is the guiding principle, in the second, converse logics, no one should have access to the technological knowledge in question. The second part contends that decisions on whether and how to grant patents in synthetic biology are not independent from institutional frameworks: The arena in which synthetic biology patenting will be dealt with will be decisive for whether and how boundaries will be deployed. From a political science perspective, the administrative, legislative and judicial arena can be distinguished. If synthetic biology will be negotiated in the legislative arena, in particular in the European Parliament, the probabilities will be higher that either the discovery clause or the ordre public clause will be applied. In contrast, patent offices and courts have, at least in the past decades, employed a narrow interpretation of these absolute exemptions from patentability and hardly ever used them. The third part asserts that metaphoric framing of synthetic biology is another crucial factor for patentability questions. Semantic framing may relate to the articulation and mobilization of consent or dissent, and thus public acceptance of synthetic biology. Whether applications of synthetic biology are conceived as "natural" or "synthetic" DNA may have an influence on whether patenting might become contested as "patenting life" or accepted as novel, and

  14. Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part II. Soil biological and biochemical properties in relation to trace element speciation.

    PubMed

    D'Ascoli, R; Rao, M A; Adamo, P; Renella, G; Landi, L; Rutigliano, F A; Terribile, F; Gianfreda, L

    2006-11-01

    The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, beta-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community. PMID:16406624

  15. Gelatin-apatite bone mimetic co-precipitates incorporated within biopolymer matrix to improve mechanical and biological properties useful for hard tissue repair.

    PubMed

    Won, Jong-Eun; El-Fiqi, Ahmed; Jegal, Seung-Hwan; Han, Cheol-Min; Lee, Eun-Jung; Knowles, Jonathan C; Kim, Hae-Won

    2014-04-01

    Synthetic biopolymers are commonly used for the repair and regeneration of damaged tissues. Specifically targeting bone, the composite approach of utilizing inorganic components is considered promising in terms of improving mechanical and biological properties. We developed gelatin-apatite co-precipitates which mimic the native bone matrix composition within poly(lactide-co-caprolactone) (PLCL). Ionic reaction of calcium and phosphate with gelatin molecules enabled the co-precipitate formation of gelatin-apatite nanocrystals at varying ratios. The gelatin-apatite precipitates formed were carbonated apatite in nature, and were homogeneously distributed within the gelatin matrix. The incorporation of gelatin-apatite significantly improved the mechanical properties, including tensile strength, elastic modulus and elongation at break, and the improvement was more pronounced as the apatite content increased. Of note, the tensile strength increased to as high as 45 MPa (a four-fold increase vs. PLCL), the elastic modulus was increased up to 1500 MPa (a five-fold increase vs. PLCL), and the elongation rate was ~240% (twice vs. PLCL). These results support the strengthening role of the gelatin-apatite precipitates within PLCL. The gelatin-apatite addition considerably enhanced the water affinity and the acellular mineral-forming ability in vitro in simulated body fluid; moreover, it stimulated cell proliferation and osteogenic differentiation. Taken together, the GAp-PLCL nanocomposite composition is considered to have excellent mechanical and biological properties, which hold great potential for use as bone regenerative matrices. PMID:23985536

  16. Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic and pharmacological properties

    NASA Astrophysics Data System (ADS)

    Papaefthimiou, Dimitra; Papanikolaou, Antigoni; Falara, Vasiliki; Givanoudi, Stella; Kostas, Stefanos; Kanellis, Angelos

    2014-06-01

    The family Cistaceae (Angiosperm, Malvales) consists of 8 genera and 180 species, with 5 genera native of the Mediterranean area (Cistus, Fumara, Halimium, Helianthemum and Tuberaria). Traditionally, a number of Cistus specie have been used in Mediterranean folk medicine as herbal tea infusions for healing, digestive problems and colds, as extracts for the treatment of diseases, and as fragrances. The resin, ladano, secreted by the glandular trichomes of certain Cistus species contains a number of phytochemicals with antioxidant, antibacterial, antifungal and anticancer properties. Furthermore, total leaf aqueous extracts possess anti-influenza virus activity. All these properties have been attributed to phytochemicals such as terpenoids, including diterpenes, labdane-type diterpenes and clerodanes, phenylpropanoids, including flavonoids and ellagitannins, several groups of alkaloids and other types of secondary metabolites. In the past 20 years, research on Cistus involved chemical, biological and phylogenetic analysis but recent investigations have involved genomic and molecular approaches. Our lab is exploring the biosynthetic machinery that generates terpenoids and phenylpropanoids, with a goal to harness their numerous properties that have applications in the pharmaceutical, chemical and aromatic industries. This review focuses on the systematics, botanical characteristics, geographic distribution, chemical analyses, biological function and biosynthesis of major compounds, as well as genomic analyses and biotechnological approaches of the main Cistus species found in the Mediterranean basin, namely C. albidus, C. creticus, C. crispus, C. parviflorus, C. monspeliensis, C. populifolius, C. salviifolius, C. ladanifer, C. laurifolius and C. clusii.

  17. Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties

    PubMed Central

    Papaefthimiou, Dimitra; Papanikolaou, Antigoni; Falara, Vasiliki; Givanoudi, Stella; Kostas, Stefanos; Kanellis, Angelos K.

    2014-01-01

    The family Cistaceae (Angiosperm, Malvales) consists of 8 genera and 180 species, with 5 genera native to the Mediterranean area (Cistus, Fumara, Halimium, Helianthemum, and Tuberaria). Traditionally, a number of Cistus species have been used in Mediterranean folk medicine as herbal tea infusions for healing digestive problems and colds, as extracts for the treatment of diseases, and as fragrances. The resin, ladano, secreted by the glandular trichomes of certain Cistus species contains a number of phytochemicals with antioxidant, antibacterial, antifungal, and anticancer properties. Furthermore, total leaf aqueous extracts possess anti-influenza virus activity. All these properties have been attributed to phytochemicals such as terpenoids, including diterpenes, labdane-type diterpenes and clerodanes, phenylpropanoids, including flavonoids and ellagitannins, several groups of alkaloids and other types of secondary metabolites. In the past 20 years, research on Cistus involved chemical, biological and phylogenetic analyses but recent investigations have involved genomic and molecular approaches. Our lab is exploring the biosynthetic machinery that generates terpenoids and phenylpropanoids, with a goal to harness their numerous properties that have applications in the pharmaceutical, chemical and aromatic industries. This review focuses on the systematics, botanical characteristics, geographic distribution, chemical analyses, biological function and biosynthesis of major compounds, as well as genomic analyses and biotechnological approaches of the main Cistus species found in the Mediterranean basin, namely C. albidus, C. creticus, C. crispus, C. parviflorus, C. monspeliensis, C. populifolius, C. salviifolius, C. ladanifer, C. laurifolius, and C. clusii. PMID:24967222

  18. Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties.

    PubMed

    Papaefthimiou, Dimitra; Papanikolaou, Antigoni; Falara, Vasiliki; Givanoudi, Stella; Kostas, Stefanos; Kanellis, Angelos K

    2014-01-01

    The family Cistaceae (Angiosperm, Malvales) consists of 8 genera and 180 species, with 5 genera native to the Mediterranean area (Cistus, Fumara, Halimium, Helianthemum, and Tuberaria). Traditionally, a number of Cistus species have been used in Mediterranean folk medicine as herbal tea infusions for healing digestive problems and colds, as extracts for the treatment of diseases, and as fragrances. The resin, ladano, secreted by the glandular trichomes of certain Cistus species contains a number of phytochemicals with antioxidant, antibacterial, antifungal, and anticancer properties. Furthermore, total leaf aqueous extracts possess anti-influenza virus activity. All these properties have been attributed to phytochemicals such as terpenoids, including diterpenes, labdane-type diterpenes and clerodanes, phenylpropanoids, including flavonoids and ellagitannins, several groups of alkaloids and other types of secondary metabolites. In the past 20 years, research on Cistus involved chemical, biological and phylogenetic analyses but recent investigations have involved genomic and molecular approaches. Our lab is exploring the biosynthetic machinery that generates terpenoids and phenylpropanoids, with a goal to harness their numerous properties that have applications in the pharmaceutical, chemical and aromatic industries. This review focuses on the systematics, botanical characteristics, geographic distribution, chemical analyses, biological function and biosynthesis of major compounds, as well as genomic analyses and biotechnological approaches of the main Cistus species found in the Mediterranean basin, namely C. albidus, C. creticus, C. crispus, C. parviflorus, C. monspeliensis, C. populifolius, C. salviifolius, C. ladanifer, C. laurifolius, and C. clusii. PMID:24967222

  19. Hybrid chitosan-ß-glycerol phosphate-gelatin nano-/micro fibrous scaffolds with suitable mechanical and biological properties for tissue engineering.

    PubMed

    Lotfi, Marzieh; Bagherzadeh, Roohollah; Naderi-Meshkin, Hojjat; Mahdipour, Elahe; Mafinezhad, Asghar; Sadeghnia, Hamid Reza; Esmaily, Habibollah; Maleki, Masoud; Hasssanzadeh, Halimeh; Ghayaour-Mobarhan, Majid; Bidkhori, Hamid Reza; Bahrami, Ahmad Reza

    2016-03-01

    Scaffold-based tissue engineering is considered as a promising approach in the regenerative medicine. Graft instability of collagen, by causing poor mechanical properties and rapid degradation, and their hard handling remains major challenges to be addressed. In this research, a composite structured nano-/microfibrous scaffold, made from a mixture of chitosan-ß-glycerol phosphate-gelatin (chitosan-GP-gelatin) using a standard electrospinning set-up was developed. Gelatin-acid acetic and chitosan ß-glycerol phosphate-HCL solutions were prepared at ratios of 30/70, 50/50, 70/30 (w/w) and their mechanical and biological properties were engineered. Furthermore, the pore structure of the fabricated nanofibrous scaffolds was investigated and predicted using a theoretical model. Higher gelatin concentrations in the polymer blend resulted in significant increase in mean pore size and its distribution. Interaction between the scaffold and the contained cells was also monitored and compared in the test and control groups. Scaffolds with higher chitosan concentrations showed higher rate of cell attachment with better proliferation property, compared with gelatin-only scaffolds. The fabricated scaffolds, unlike many other natural polymers, also exhibit non-toxic and biodegradable properties in the grafted tissues. In conclusion, the data clearly showed that the fabricated biomaterial is a biologically compatible scaffold with potential to serve as a proper platform for retaining the cultured cells for further application in cell-based tissue engineering, especially in wound healing practices. These results suggested the potential of using mesoporous composite chitosan-GP-gelatin fibrous scaffolds for engineering three-dimensional tissues with different inherent cell characteristics. PMID:26566174

  20. Short-Term Effect of Vermicompost Application on Biological Properties of an Alkaline Soil with High Lime Content from Mediterranean Region of Turkey

    PubMed Central

    Uz, Ilker; Tavali, Ismail Emrah

    2014-01-01

    This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, β-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. β-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

  1. Short-term effect of vermicompost application on biological properties of an alkaline soil with high lime content from Mediterranean region of Turkey.

    PubMed

    Uz, Ilker; Tavali, Ismail Emrah

    2014-01-01

    This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, β-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. β-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

  2. FREEDOM TO OPERATE: Intellectual Property Protection in Plant Biology and Its Implications for the Conduct of Research.

    PubMed

    Kimpel, J A

    1999-09-01

    ▪ Abstract  Research endeavors are being affected by issues involving intellectual property (patents, copyrights, and trademarks). The acquisition of rights in intellectual property by universities can result in the transfer of new innovations to the private sector, with the university recouping a share of the profits for support of further scientific research. Intellectual property rights available for new plant cultivars include plant patents, plant variety protection certificates, plant breeder's rights, and utility patents. Under the patent laws, there is no explicit exemption for research use, so researchers are increasingly being required to execute materials transfer agreements to obtain permission to use patented materials, such as techniques, genes, seeds, and cell lines, in laboratory research and in breeding programs. Research scientists must educate themselves on these issues so that they can make informed decisions regarding their research practices and the licensing of their discoveries. PMID:11701816

  3. Synthesis of organometallic-based biologically active compounds: In vitro antibacterial, antifungal and cytotoxic properties of some sulfonamide incorporated ferrocences.

    PubMed

    Chohan, Zahid H

    2009-02-01

    Sulfonamides incorporated ferrocene (SIF) have been synthesized by the condensation reaction of sulfonamides (sulfanilamide, sulfathiazole or sulfamethaxazole) with 1,1'-diacetylferrocene. The synthesized compounds (SIF(1)-SIF(4)) have been characterized by their physical, spectral and analytical properties and have been screened for their in vitro antibacterial properties against pathogenic bacterial strains e.g., Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis Staphylococcus aureus and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata using Agar-well diffusion method. Most of the compounds showed good antibacterial activity whereas, all the compounds exhibited significant antifungal activity. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina. PMID:18608785

  4. Behaviour of oxyfluorfen in soils amended with edaphic biostimulants/biofertilizers obtained from sewage sludge and chicken feathers. Effects on soil biological properties.

    PubMed

    Rodríguez-Morgado, Bruno; Gómez, Isidoro; Parrado, Juan; Tejada, Manuel

    2014-09-01

    We studied the behaviour of oxyfluorfen herbicide at a rate of 4 l ha(-1) on biological properties of a Calcaric Regosol amended with two edaphic biostimulants/biofertilizers (SS, derived from sewage sludge; and CF, derived from chicken feathers). Oxyfluorfen was surface broadcast on 11 March 2013. Two days after application of oxyfluorfen to soil, both biostimulants/biofertilizers (BS) were also applied to the soil. An unamended soil without oxyfluorfen was used as control. For 2, 4, 7, 9, 20, 30, 60, 90 and 120 days of the application of herbicide to the soil and for each treatment, the soil dehydrogenase, urease, β-glucosidase and phosphatase activities were measured. For 2, 7, 30 and 120 days of the application of herbicide to the soil and for each treatment, soil microbial community was determined. The application of both BS to soil without the herbicide increased the enzymatic activities and soil biodiversity, mainly at 7 days of beginning the experiment. However, this stimulation was higher in the soil amended with SS than for CF. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly, the low-molecular-weight protein content easily assimilated by soil microorganisms is responsible for less inhibition of these soil biological properties. PMID:24859703

  5. A Modular Class of Fluorescent Difluoroboranes: Synthesis, Structure, Optical Properties, Theoretical Calculations and Applications for Biological Imaging.

    PubMed

    Bachollet, Sylvestre P J T; Volz, Daniel; Fiser, Béla; Münch, Stephan; Rönicke, Franziska; Carrillo, Jokin; Adams, Harry; Schepers, Ute; Gómez-Bengoa, Enrique; Bräse, Stefan; Harrity, Joseph P A

    2016-08-22

    Ten borylated bipyridines (BOBIPYs) have been synthesized and selected structural modifications have been made that allow useful structure-optical property relationships to be gathered. These systems have been further investigated using DFT calculations and spectroscopic measurements, showing blue to green fluorescence with quantum yields up to 41 %. They allow full mapping of the structure to determine where selected functionalities can be implemented, to tune the optical properties or to incorporate linking groups. The best derivative was thus functionalised with an alkyne linker, which would enable further applications through click chemistry and in this optic, the stability of the fluorophores has been evaluated. PMID:27465819

  6. Poly(ether ester amide) microspheres for protein delivery: influence of copolymer composition on technological and biological properties.

    PubMed

    Ostacolo, Luisanna; Russo, Paola; De Rosa, Giuseppe; La Rotonda, Maria Immacolata; Maglio, Giovanni; Nese, Giuseppe; Spagnuolo, Gianrico; Rengo, Sandro; Oliva, Adriana; Quaglia, Fabiana

    2008-07-01

    The production of PEEA microspheres with potential as carriers for protein oral delivery is described. PEEAs with different hydrophilicity were synthesized and characterized. Experiments showed that an increase in copolymer hydrophilicity gave particles less prone to cell interaction. BSA release profiles from PEEA microspheres demonstrated that an increase in polymer hydrophilicity was useful in limiting protein burst and modulating drug delivery rate by increasing PEEA degradability. These results show that fine-tuning of the hydrophilic/hydrophobic properties of PCL is essential for the formulation protein-loaded microspheres with specific properties. PMID:18412287

  7. A human-phantom coupling experiment and a dispersive simulation model for investigating the variation of dielectric properties of biological tissues.

    PubMed

    Gomez-Tames, Jose; Fukuhara, Yuto; He, Siyu; Saito, Kazuyuki; Ito, Koichi; Yu, Wenwei

    2015-06-01

    Variation of the dielectric properties of tissues could happen due to aging, moisture of the skin, muscle denervation, and variation of blood flow by temperature. Several studies used burst-modulated alternating stimulation to improve activation and comfort by reducing tissue impedance as a possible mechanism to generate muscle activation with less energy. The study of the effect of dielectric properties of biological tissues in nerve activation presents a fundamental problem, which is the difficulty of systematically changing the morphological factors and dielectric properties of the subjects under study. We tackle this problem by using a simulation and an experimental study. The experimental study is a novel method that combines a fat tissue-equivalent phantom, with known and adjustable dielectric properties, with the human thigh. In this way, the dispersion of the tissue under study could be modified to observe its effects systematically in muscle activation. We observed that, to generate a given amount of muscle or nerve activation under conditions of decreased impedance, the magnitude of the current needs to be increased while the magnitude of the voltage needs to be decreased. PMID:25909642

  8. [Tissue repair of uterine cervix--cell-biological properties of normal uterine cervical epithelia of transformation zone in vitro].

    PubMed

    Ishiwata, I; Sakuma, T; Nozawa, S

    1991-09-01

    The objective of this study is to culture the epithelia of the transformation zone of the uterine cervix for long term and evaluate their biological characteristics, such as morphology, growth behavior, alkaline phosphatase activity and heterotransplantability. The epithelia of transformation zone of 15 cases of myoma uteri were cut into 1 x 1 x 1 mm fragments and placed directly on the cover glass. The explants were cultured at 37 degrees C in 5% CO2 and 95% air. In vitro outgrowth of squamous cells (squamous cell outgrowth pattern) was observed in 44, that of columnar cells (columnar cell outgrowth pattern) was observed 49, a mixture of squamous and columnar cell outgrowth patterns was 52 out of 198 explants of transformation zone. The squamous cells were polygonal in shape and showed a pavement-like cell arrangement. The glandular cells grew in whorled fashion. Along the margins of the outgrowth of glandular cells, two types of cells were seen after 2 weeks of culture. One type contained secretory vacuoles of glandular cell, and the other type contained a large number of tonofilaments of squamous metaplastic cells. These phenomena suggested that biological characteristics of the cells in vivo can well be retained in vitro for a relative long term (about 6 weeks). PMID:1723625

  9. Correlation between surface physicochemical properties and the release of iron from stainless steel AISI 304 in biological media.

    PubMed

    Hedberg, Yolanda; Karlsson, Maria-Elisa; Blomberg, Eva; Odnevall Wallinder, Inger; Hedberg, Jonas

    2014-10-01

    Stainless steel is widely used in biological environments, for example as implant material or in food applications, where adsorption-controlled ligand-induced metal release is of importance from a corrosion, health, and food safety perspective. The objective of this study was to elucidate potential correlations between surface energy and wettability of stainless steel surfaces and the release of iron in complexing biological media. This was accomplished by studying changes in surface energies calculated from contact angle measurements, surface oxide composition (X-ray photoelectron spectroscopy), and released iron (graphite furnace atomic absorption spectroscopy) for stainless steel grade AISI 304 immersed in fluids containing bovine serum albumin or citric acid, and non-complexing fluids such as NaCl, NaOH, and HNO3. It was shown that the surface wettability and polar surface energy components were all influenced by adventitious atmospheric carbon (surface contamination of low molecular weight), rather than differences in surface oxide composition in non-complexing solutions. Adsorption of both BSA and citrate, which resulted in ligand-induced metal release, strongly influenced the wettability and the surface energy, and correlated well with the measured released amount of iron. PMID:25048358

  10. LASER BIOLOGY AND MEDICINE: Recording of lymph flow dynamics in microvessels using correlation properties of scattered coherent radiation

    NASA Astrophysics Data System (ADS)

    Fedosov, I. V.; Tuchin, Valerii V.; Galanzha, E. I.; Solov'eva, A. V.; Stepanova, T. V.

    2002-11-01

    The direction-sensitive method of microflow velocity measurements based on the space — time correlation properties of the dynamic speckle field is described and used for in vivo monitoring of lymph flow in the vessels of rat mesentery. The results of measurements are compared with the data obtained from functional video microscopy of the microvessel region.

  11. Chemical, physical and biological properties of a marginal soil as influenced by tillage and broiler litter application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion changes the soil properties, mainly because it removes surface soil rich in organic matter and exposes lower soil layers. Many soils in Mississippi were degraded by erosion and nutrient depletion when these were row-cropped years ago. A study was initiated in 2005 in an eroded Loring silt l...

  12. Effects of Zero Tillage (No-Till) Conservation Agriculture on soil physical and biological properties and their contributions to sustainability

    NASA Astrophysics Data System (ADS)

    Landers, John N.; Rass, Gerard; de Freitas, Pedro L.; Basch, Gottlieb; González Sanchez, Emilio J.; Tabaglio, Vincenzo; Kassan, Amir; Derpsch, Rolf; Friedrich, Theodor; Giupponi, Luca

    2013-04-01

    Not cultivating soil, rotating crops over the years, and leaving crop residues on the surface in the practice of zero tillage/conservation agriculture (ZT/CA) reverses the historically accelerating degradation of soil organic matter (SOM) and soil structure, while increasing soil biological activity by a factor of 2 to 4. The results of this are many: (a) not cultivating reduces soil compaction, leaving old root holes to facilitate internal drainage, averts the pulverization of soil aggregates and formation of pans, reduces draft power for planting and gives shelter, winter food and nesting sites for fauna, (b) crop residues on the surface practically eliminate wind and water erosion, reduce soil moisture loss through the mulch effect, slow spring warm-up (possibly offset by a lower specific heat demand with less water retention in surface soil) and act as a reserve of organically-compounded nutrients (as they decompose to humus), (c) more SOM means higher available water and nutrient retention, higher biological activity year round (enhancing biological controls), higher levels of water-stable aggregates and a positive carbon sink in incremental SOM. The positive impacts for society are: (i) more and cheaper food, (ii) reduced flood and drought-induced famine risks, (iii) a positive carbon sink in SOM and possible reductions in NO2 emissions, (iv) cleaner water and greater aquifer recharge due to reduced runoff, (v) cleaner air through effective elimination of dust as a product of cultivation (vi) less water pollution and greater aquifer recharge from reduced rainfall runoff, (vii) farm diesel consumption halved, (viii) reduced demand for (tropical) de-forestation, by permitting crop expansion on steeper lands, (ix) increased wildlife populations (skylarks, plovers, partridge and peccaries) and (x) an improved conservation mindset in farmers. It is notable that, in spite of successful practitioners in all European countries, mainstream adoption is still to come

  13. Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

    PubMed Central

    Dyment, Nathaniel A.; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Butler, David L.

    2015-01-01

    The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair. PMID:25266738

  14. Synthesis, characterization and biological properties of thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes.

    PubMed

    Chohan, Zahid H; Sumrra, Sajjad H

    2012-04-01

    A new series of biologically active thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (IR, ¹H and ¹³C NMR, electronic and mass spectrometry) and microanalytical data. All the Schiff base ligands and their oxovanadium(IV) complexes have been subjected to in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella enterica serover typhi) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains and, for in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glabrata. Brine shrimp bioassay was also carried out to check the cytotoxic nature of these compounds. PMID:21635212

  15. Influence of Nano-Crystal Metals on Texture and Biological Properties of Water Soluble Polysaccharides of Medicinal Plants

    NASA Astrophysics Data System (ADS)

    Churilov, G.; Ivanycheva, J.; Kiryshin, V.

    2015-11-01

    When treating the plants seeds with nano-materials there are some quality and quantity changes of polysaccharides, the molecular mass increase and monosaccharides change that leads to the increase of physiological and pharmacological activity of carbohydrates got from medicinal plants. We have got water soluble polysaccharides and nano-metals combinations containing 0.000165-0.000017 mg/dm3 of the metal. In a case of induced anemia the blood composition has practically restored on the 10th day of the treatment with nanocomposites. The use of pectin polysaccharides (that are attributed to modifiers of biological respond) to get nano-structured materials seems to be actual relative to their physiological activity (radio nuclides persorption, heavy metals ions, bacteria cells and their toxins; lipids metabolism normalization; bowels secreting and motor functions activation and modulation of the endocrine system.

  16. Development and evaluation of a pliable biological valved conduit. Part I: Preparation, biochemical properties, and histological findings.

    PubMed

    Noishiki, Y; Hata, C; Tu, R; Shen, S H; Lin, D; Sung, H W; Witzel, T; Wang, E; Thyagarajan, K; Tomizawa, Y

    1993-04-01

    Different types of external valved conduits have been used for the repair of complex congenital cardiac anomalies that may have otherwise been inoperable. However, an ideal conduit has yet to be found due to complications such as stenosis, thrombosis, calcification of the valve and graft wall, and "peeling" of the neointima. To address those problems, a new extracardiac valved conduit made of bovine jugular vein was developed and evaluated in a preliminary animal study. Harvested bovine vein containing a naturally existing valve was initially incorporated with protamine on the inner surface and then was cross-linked in diglycidyl ether (DE). Fixation with DE allowed the vein and its leaflets to retain a tissue-like elasticity. To provide antithrombogenicity to the graft, heparin was introduced into the lumen to bind ionically to the pre-entrapped protamine. The biological valved conduit of approximately 14 mm diameter was implanted from the right ventricle to pulmonary artery as bypass graft in three dogs. After implantation, the native main pulmonary artery was ligated between the anastomotic sites of the bypass conduit. No anticoagulant or antiplatelet drugs were administered after surgery. One DE-fixed valved conduit was retrieved at 3 months, and the others were removed at 5 months. Only small thrombus areas were found on the white luminal surfaces. The valves and the conduits maintained softness and pliability, similar to before implantation. Additionally, the collagen content, shrink temperature, and tanning index of this newly developed biological valved conduit before and after fixation were measured in the study.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8325696

  17. Characterization and biological properties of NanoCUR formulation and its effect on major human cytochrome P450 enzymes.

    PubMed

    Shamsi, Suhaili; Chen, Yan; Lim, Lee Yong

    2015-11-10

    Curcumin (CUR) has been formulated into a host of nano-sized formulations in a bid to improve its in vivo solubility, stability and bioavailability. The aim of this study was to investigate whether the encapsulation of CUR in nanocarriers would impede its biological interactivity, specifically its potential anti-cancer adjuvant activity via the modulation of CYP enzymes in vitro. NanoCUR, a micellar dispersion prepared via a thin film method using only Pluronic F127 as excipient, was amenable to lyophilization, and retained its nano-sized spherical dimensions (17-33 nm) upon reconstitution with water followed by dilution to 5 μM with HBSS or EMEM. NanoCUR was a weaker cytotoxic agent compared to CUR in solution (sCUR), affecting HepG2 cell viability only when the incubation time was prolonged from 4h to 48 h. Correlation with 2h uptake data suggests this was due to a lower cellular uptake rate of CUR from NanoCUR than from sCUR. The poorer CUR accessibility might also account for NanoCUR being a weaker inhibitor of CYP2C9 and CYP2D6 than sCUR. NanoCUR was, however, 1.76-fold more potent against the CYP3A4 (IC50 5.13 ± 0.91 μM) metabolic function. The higher activity against CYP3A4 might be attributed to the synergistic action of Pluronic F127, since the blank micellar dispersion also inhibited CYP3A4 activity. Both sCUR and NanoCUR had no effect on the CYP3A4 mRNA levels in the HepG2 cells. NanoCUR therefore, maintained most of the biological activities of CUR in vitro, albeit at a lower potency and response rate. PMID:26319630

  18. Imaging a full set of optical scattering properties of biological tissue by inverse spectroscopic optical coherence tomography.

    PubMed

    Yi, Ji; Backman, Vadim

    2012-11-01

    We here develop a method to measure and image the full optical scattering properties by inverse spectroscopic optical coherence tomography (ISOCT). Tissue is modelled as a medium with continuous refractive index (RI) fluctuation and such a fluctuation is described by the RI correlation functions. Under the first-order Born approximation, the forward model is established for ISOCT. By measuring optical quantities of tissue including the scattering power of the OCT spectrum, the reflection albedo α defined as the ratio of scattering coefficient μ(s), and the backscattering coefficient μ(b), we are able to inversely deduce the RI correlation function and image the full set of optical scattering properties. PMID:23114323

  19. Property.

    ERIC Educational Resources Information Center

    Goldblatt, Steven M.

    In this chapter on decisions made by federal and state courts during 1983 concerning school property it is noted that no new trends emerged during the year. Among the topics addressed are the extent of school board authority over property use and other property matters; the attachment and detachment of land from school district holdings; school…

  20. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Several court cases involving acquisition, use, and disposal of property by institutions of higher education are briefly summarized in this chapter. Cases discussed touch on such topics as municipal annexation of university property; repurchase of properties temporarily allocated to faculty members; implications of zoning laws and zoning board…

  1. Physical Properties and Biological Activity of Poly(butyl acrylate–styrene) Nanoparticle Emulsions Prepared with Conventional and Polymerizable Surfactants

    PubMed Central

    Garay-Jimenez, Julio C.; Gergeres, Danielle; Young, Ashley; Dickey, Sonja; Lim, Daniel V.; Turos, Edward

    2009-01-01

    Recent efforts in our laboratory have explored the use of polyacrylate nanoparticles in aqueous media as stable emulsions for potential applications in treating drug-resistant bacterial infections. These emulsions are made by emulsion polymerization of acrylated antibiotic compounds in a mixture of butyl acrylate and styrene (7:3 w:w) using sodium dodecyl sulfate (SDS) as a surfactant. Prior work in our group established that the emulsions required purification to remove toxicity associated with extraneous surfactant present in the media. This paper summarizes our investigations of poly(butyl acrylate-styrene) emulsions made using anionic, cationic, zwitterionic, and non-charged (amphiphilic) surfactants, as well as attachable surfactant monomers (surfmers), comparing the cytotoxicity and microbiological activity levels of the emulsion both before and after purification. Our results show that the attachment of a polymerizable surfmer onto the matrix of the nanoparticle neither improves nor diminishes cytotoxic or antibacterial effects of the emulsion, regardless of whether the emulsions are purified or not, and that the optimal properties are associated with the use of the non-ionic surfactants versus those carrying anionic, cationic, or zwitterionic charge. Incorporation of an N-thiolated β-lactam antibacterial agent onto the nanoparticle matrix via covalent attachment endows the emulsion with antibiotic properties against pathogenic bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), without changing the physical properties of the nanoparticles or their emulsions. PMID:19523413

  2. Changes in Microbial Community Structure and Soil Biological Properties in Mined Dune Areas During Re-vegetation

    NASA Astrophysics Data System (ADS)

    Escobar, Indra Elena C.; Santos, Vilma M.; da Silva, Danielle Karla A.; Fernandes, Marcelo F.; Cavalcante, Uided Maaze T.; Maia, Leonor C.

    2015-06-01

    The aim of this study was to describe the impact of re-vegetation on the restoration of microbial community structure and soil microbiological properties in sand dunes that had been affected by mining activity. Soil samples were collected during the dry and rainy seasons from a chronosequence (1, 9, 21 years) of re-vegetated dunes using a single preserved dune as a reference. The composition of the fatty acid methyl esters and soil microbial properties were evaluated. The results showed that the changes in microbial community structure were related to seasonal variations: biomarkers of Gram-positive bacteria were higher than Gram-negative bacteria during the dry season, showing that this group of organisms is more tolerant to these stressful conditions. The microbial community structure in the natural dune was less affected by seasonal variation compared to the re-vegetated areas, whereas the opposite was observed for microbiological properties. Thus, in general, the proportion of saprobic fungi was higher in the natural dune, whereas Gram-negative bacteria were proportionally more common in the younger areas. Although over time the re-vegetation allows the recovery of the microbial community and the soil functions, these communities and functions are different from those found in the undisturbed areas.

  3. Trabecular meshwork cell culture in glaucoma research: evaluation of biological activity and structural properties of human trabecular cells in vitro.

    PubMed

    Polansky, J R; Wood, I S; Maglio, M T; Alvarado, J A

    1984-06-01

    The propagation of human trabecular cells in culture allows the study of the structural and functional properties of this distinct cell type under reproducible experimental conditions. Human trabecular cells can be effectively grown from dissected explants of trabecullar tissue, and the cultured cells can maintain the distinctive ultrastructural features of uncultured trabecular cells through at least five passages in vitro. The trabecular cell possesses a wide range of biochemical and structural properties that may be important for the maintenance of the aqueous outflow pathway. These properties include the growth of trabecular cells as an endothelial monolayer with a nonthrombogenic cell surface, the production of plasminogen activator, avid phagocytosis, and the ability to synthesize glycosaminoglycans, collagen, fibronectin, and other connective tissue elements. The presence of hyaluronidase and other lysosomal enzymes emphasizes that human trabecular cells are capable of metabolizing hyaluronic acid and other extracellular materials. Potential mechanisms of trabecular cell damage in vitro are examined by evaluating the effects of extended passage, peroxide exposure, and laser treatment on cellular morphology. PMID:6540429

  4. Changes in Microbial Community Structure and Soil Biological Properties in Mined Dune Areas During Re-vegetation.

    PubMed

    Escobar, Indra Elena C; Santos, Vilma M; da Silva, Danielle Karla A; Fernandes, Marcelo F; Cavalcante, Uided Maaze T; Maia, Leonor C

    2015-06-01

    The aim of this study was to describe the impact of re-vegetation on the restoration of microbial community structure and soil microbiological properties in sand dunes that had been affected by mining activity. Soil samples were collected during the dry and rainy seasons from a chronosequence (1, 9, 21 years) of re-vegetated dunes using a single preserved dune as a reference. The composition of the fatty acid methyl esters and soil microbial properties were evaluated. The results showed that the changes in microbial community structure were related to seasonal variations: biomarkers of Gram-positive bacteria were higher than Gram-negative bacteria during the dry season, showing that this group of organisms is more tolerant to these stressful conditions. The microbial community structure in the natural dune was less affected by seasonal variation compared to the re-vegetated areas, whereas the opposite was observed for microbiological properties. Thus, in general, the proportion of saprobic fungi was higher in the natural dune, whereas Gram-negative bacteria were proportionally more common in the younger areas. Although over time the re-vegetation allows the recovery of the microbial community and the soil functions, these communities and functions are different from those found in the undisturbed areas. PMID:25822889

  5. Biological Threats

    MedlinePlus

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Biological Threats Biological agents are organisms or toxins that ... Centers for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may ...

  6. Modeling biophysical and biological properties from the characteristics of the molecular electron density, electron localization and delocalization matrices, and the electrostatic potential.

    PubMed

    Matta, Chérif F

    2014-06-15

    The electron density and the electrostatic potential are fundamentally related to the molecular hamiltonian, and hence are the ultimate source of all properties in the ground- and excited-states. The advantages of using molecular descriptors derived from these fundamental scalar fields, both accessible from theory and from experiment, in the formulation of quantitative structure-to-activity and structure-to-property relationships, collectively abbreviated as QSAR, are discussed. A few such descriptors encode for a wide variety of properties including, for example, electronic transition energies, pK(a)'s, rates of ester hydrolysis, NMR chemical shifts, DNA dimers binding energies, π-stacking energies, toxicological indices, cytotoxicities, hepatotoxicities, carcinogenicities, partial molar volumes, partition coefficients (log P), hydrogen bond donor capacities, enzyme-substrate complementarities, bioisosterism, and regularities in the genetic code. Electronic fingerprinting from the topological analysis of the electron density is shown to be comparable and possibly superior to Hammett constants and can be used in conjunction with traditional bulk and liposolubility descriptors to accurately predict biological activities. A new class of descriptors obtained from the quantum theory of atoms in molecules' (QTAIM) localization and delocalization indices and bond properties, cast in matrix format, is shown to quantify transferability and molecular similarity meaningfully. Properties such as "interacting quantum atoms (IQA)" energies which are expressible into an interaction matrix of two body terms (and diagonal one body "self" terms, as IQA energies) can be used in the same manner. The proposed QSAR-type studies based on similarity distances derived from such matrix representatives of molecular structure necessitate extensive investigation before their utility is unequivocally established. PMID:24777743

  7. Modeling Biophysical and Biological Properties From the Characteristics of the Molecular Electron Density, Electron Localization and Delocalization Matrices, and the Electrostatic Potential

    PubMed Central

    Matta*, Chérif F

    2014-01-01

    The electron density and the electrostatic potential are fundamentally related to the molecular hamiltonian, and hence are the ultimate source of all properties in the ground- and excited-states. The advantages of using molecular descriptors derived from these fundamental scalar fields, both accessible from theory and from experiment, in the formulation of quantitative structure-to-activity and structure-to-property relationships, collectively abbreviated as QSAR, are discussed. A few such descriptors encode for a wide variety of properties including, for example, electronic transition energies, pKa's, rates of ester hydrolysis, NMR chemical shifts, DNA dimers binding energies, π-stacking energies, toxicological indices, cytotoxicities, hepatotoxicities, carcinogenicities, partial molar volumes, partition coefficients (log P), hydrogen bond donor capacities, enzyme–substrate complementarities, bioisosterism, and regularities in the genetic code. Electronic fingerprinting from the topological analysis of the electron density is shown to be comparable and possibly superior to Hammett constants and can be used in conjunction with traditional bulk and liposolubility descriptors to accurately predict biological activities. A new class of descriptors obtained from the quantum theory of atoms in molecules' (QTAIM) localization and delocalization indices and bond properties, cast in matrix format, is shown to quantify transferability and molecular similarity meaningfully. Properties such as “interacting quantum atoms (IQA)” energies which are expressible into an interaction matrix of two body terms (and diagonal one body “self” terms, as IQA energies) can be used in the same manner. The proposed QSAR-type studies based on similarity distances derived from such matrix representatives of molecular structure necessitate extensive investigation before their utility is unequivocally established. © 2014 The Author and the Journal of Computational Chemistry Published

  8. Irradiation of poly(tetrafluoroethylene) surfaces by CF4 plasma to achieve robust superhydrophobic and enhanced oleophilic properties for biological applications.

    PubMed

    Salapare, Hernando S; Suarez, Beverly Anne T; Cosiñero, Hannah Shamina O; Bacaoco, Miguel Y; Ramos, Henry J

    2015-01-01

    Poly(tetrafluoroethylene) (PTFE) was irradiated by CF4 plasma produced in the gas discharge ion source facility to produce stable and robust superhydrophobic surfaces and to enhance the materials' oleophilic property for biological applications. The characterizations employed on the samples are contact angle measurements, analysis of the surface morphology (scanning electron microscopy), surface roughness measurements (atomic force microscopy) and analysis of the surface chemistry (Fourier transform infrared spectroscopy). Superhydrophobic behavior with water contact angles as high as 156° was observed. The wettability of all the treated samples was found to be stable in time as evidenced by the statistically insignificant differences in the hysteresis contact angles. The level of enhanced hydrophobicity depended on the plasma energies (i.e. irradiation times, discharge current, and discharge voltage); higher plasma energies produced surfaces with high hydrophobicity. The plasma treatment also enhanced the oleophilic property of the materials' surface as evidenced by the decrease in the PDMS-oil contact angle from 33° to as low as 10°. The superhydrophobicity of the modified PTFE and the enhancement of its oleophilic property were due to (1) the changes in the roughness of the surface, (2) the formation of nanoparticles or nanostructures on the surface, and (3) the changes in the surface chemistry. PMID:25491987

  9. Gradient-based Electrical Properties Tomography (gEPT): a Robust Method for Mapping Electrical Properties of Biological Tissues In Vivo Using Magnetic Resonance Imaging

    PubMed Central

    Liu, Jiaen; Zhang, Xiaotong; Schmitter, Sebastian; Van de Moortele, Pierre-Francois; He, Bin

    2014-01-01

    Purpose To develop high-resolution electrical properties tomography (EPT) methods and investigate a gradient-based EPT (gEPT) approach which aims to reconstruct the electrical properties (EP), including conductivity and permittivity, of an imaged sample from experimentally measured B1 maps with improved boundary reconstruction and robustness against measurement noise. Theory and Methods Using a multi-channel transmit/receive stripline head coil, with acquired B1 maps for each coil element, by assuming negligible Bz component compared to transverse B1 components, a theory describing the relationship between B1 field, EP value and their spatial gradient has been proposed. The final EP images were obtained through spatial integration over the reconstructed EP gradient. Numerical simulation, physical phantom and in vivo human experiments at 7 T have been conducted to evaluate the performance of the proposed methods. Results Reconstruction results were compared with target EP values in both simulations and phantom experiments. Human experimental results were compared with EP values in literature. Satisfactory agreement was observed with improved boundary reconstruction. Importantly, the proposed gEPT method proved to be more robust against noise when compared to previously described non-gradient-based EPT approaches. Conclusion The proposed gEPT approach holds promises to improve EP mapping quality by recovering the boundary information and enhancing robustness against noise. PMID:25213371

  10. Alkali Metal Ion Complexes with Phosphates, Nucleotides, Amino Acids, and Related Ligands of Biological Relevance. Their Properties in Solution.

    PubMed

    Crea, Francesco; De Stefano, Concetta; Foti, Claudia; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

    2016-01-01

    Alkali metal ions play very important roles in all biological systems, some of them are essential for life. Their concentration depends on several physiological factors and is very variable. For example, sodium concentrations in human fluids vary from quite low (e.g., 8.2 mmol dm(-3) in mature maternal milk) to high values (0.14 mol dm(-3) in blood plasma). While many data on the concentration of Na(+) and K(+) in various fluids are available, the information on other alkali metal cations is scarce. Since many vital functions depend on the network of interactions occurring in various biofluids, this chapter reviews their complex formation with phosphates, nucleotides, amino acids, and related ligands of biological relevance. Literature data on this topic are quite rare if compared to other cations. Generally, the stability of alkali metal ion complexes of organic and inorganic ligands is rather low (usually log K < 2) and depends on the charge of the ligand, owing to the ionic nature of the interactions. At the same time, the size of the cation is an important factor that influences the stability: very often, but not always (e.g., for sulfate), it follows the trend Li(+) > Na(+) > K(+) > Rb(+) > Cs(+). For example, for citrate it is: log K ML = 0.88, 0.80, 0.48, 0.38, and 0.13 at 25 °C and infinite dilution. Some considerations are made on the main aspects related to the difficulties in the determination of weak complexes. The importance of the alkali metal ion complexes was also studied in the light of modelling natural fluids and in the use of these cations as probes for different processes. Some empirical relationships are proposed for the dependence of the stability constants of Na(+) complexes on the ligand charge, as well as for correlations among log K values of NaL, KL or LiL species (L = generic ligand). PMID:26860301

  11. Phthalocyanine-cRGD conjugate: synthesis, photophysical properties and in vitro biological activity for targeting photodynamic therapy.

    PubMed

    Luan, Liqiang; Fang, Wenjuan; Liu, Wei; Tian, Minggang; Ni, Yuxing; Chen, Xi; Yu, Xiaoqiang

    2016-03-01

    An unsymmetrical phthalocyanine conjugated with an RGDyK moiety () was synthesized and characterized. Its photophysical properties, including electronic absorption, fluorescence emission (ΦF = 0.20), singlet oxygen quantum yield (ΦΔ = 0.63) and two-photon absorption cross section (TPACS) at different wavelengths were studied. The in vitro cell study data demonstrate that this Pc conjugate possesses significantly high cellular uptake toward the ανβ3 positive DU145 prostate cancer cells along with an efficient photocytotoxicity (IC50 = 0.04 μM), showing this compound is one of the most promising photosensitizers for targeting photodynamic therapy (PDT) of cancer. PMID:26883209

  12. The nonconservative property of dissolved molybdenum in the western Taiwan Strait: Relevance of submarine groundwater discharges and biological utilization

    NASA Astrophysics Data System (ADS)

    Wang, Deli; Xia, Weiwei; Lu, Shuimiao; Wang, Guizhi; Liu, Qian; Moore, Willard S.; Arthur Chen, Chen-Tung

    2016-01-01

    This study examined dissolved Mo and sedimentary Mo along with hydrochemical parameters in the western Taiwan Strait (WTS) in May and August 2012. The results demonstrate that dissolved Mo could be depleted of as high as 10-20 nM during our May sampling period when the nutrient-enriched Min-Zhe coastal current ceased and spring blooms developed. The negative correlation between Chl-a and dissolved Mo suggests the possible involvement of high algal productivity in removing dissolved Mo out of the water column. Specific oceanographic settings (little currents) permitted a high sedimentary enrichment of Mo (>6 µg/g Mo) within the highly productive waters outside the Jiulong River mouth. Possibly, the high algal productivities and consequent organic matter sinks provide a pathway of Mo burial from water columns into sediments. Dissolved Mo was relatively high in groundwater samples, but we observed that submarine groundwater discharges (SGDs) only contributed to a relatively small percentage of the total dissolved Mo pool in WTS. It is probably attributable to the immediate removal of SGD-released Mo ions via adsorption onto newly formed Mn oxides once exposed to oxygenated seawater, followed by an elevated sedimentary Mo accumulation near the SGDs (˜5 µg/g). In addition to metal oxide particle scavenging and sulfide precipitation, we estimated that biological uptake along with Mo adsorption onto organic matter carriers could finally provide more than 10% of the annual sedimentary Mo accumulation in WTS.

  13. Excited-state properties and physiological functions of biological polyenes: the triplet-excited region of retinoids and carotenoids

    NASA Astrophysics Data System (ADS)

    Koyama, Y.; Mukai, Yumiko; Kuki, Michitaka

    1993-06-01

    Both experimental and theoretical results which indicate the presence of the triplet-excited region in retinoids and carotenoids are reviewed. The triplet- excited region is defined as a region where changes in the bond order take place, upon triplet excitation, toward its inversion, i.e., a double bond becomes more signal bond-like and a single bond becomes more double bond-like. (1) It has a span of approximately six conjugated double bonds, (2) it is localized in the central part of a conjugated chain, and (3) it triggers `cis' to `trans' isomerization in the T1 state. The experimental and theoretical results include: (1) the T1 Raman spectra of all-trans-retinal and its homologues; (2) the T1-state isomerization of isomeric retinal; (3) the T1-state isomerization of isomeric (beta) -carotene; (4) the PPP-SD-CI calculations of the bond orders of the carbon-carbon bonds in a set of model polyenes; and (5) the normal-coordinate analysis of the T1 Raman lines of undeuterated and deuterated all-trans-retinal. Finally, (6) the biological implication of 'the triplet-excited region' is discussed in relation to the photo-protective function of a 15-cis carotenoid bound to the bacterial photoreaction center.

  14. Supramolecular structural, thermal properties and biological activity of 3-(2-methoxyphenoxy)propane-1,2-diol metal complexes

    NASA Astrophysics Data System (ADS)

    Mahmoud, Walaa H.; Mahmoud, Nessma F.; Mohamed, Gehad G.; El-Bindary, Ashraf A.; El-Sonbati, Adel Z.

    2015-04-01

    New bi- and trivalent transition metal complexes of ligand 3-(2-methoxyphenoxy)propane-1,2-diol (GFS) were synthesized. The ligand and complexes were characterized via: melting point, UV/Visible, IR, 1H NMR, mass and diffused reflectance spectroscopy. The molecular structure of the investigated ligand (GFS) is optimized theoretically and the quantum chemical parameters are calculated. In addition, the complexes were characterized based on conductivity measurement, thermal analysis and biological activity. The infrared spectral study of GFS and its complexes, act as monobasic tridentate through the oxygen atom of hydroxyl group and two etheric oxygen atoms. Also, coordination to the unprotonated oxygen is evidenced from the disappearance of the OH signal in the 1H NMR spectra after complexation. The thermogravimetric analysis of the complexes shows metal oxide remaining as the final product. The compounds were tested against four bacterial species; two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) as well as antifungal activity against (Candida albicans). The complexes showed significant activities against Gram positive bacteria than Gram negative bacteria. [Cd(GFS)Cl(H2O)2] complex showed remarkable antifungal activity. However, some complexes showed more chemotherapeutic efficiency than the parent GFS drug. The drug and complexes were also screened for their in vitro anticancer activity against the Breast cell line (MFC7) and the results obtained show that they exhibit a considerable anticancer activity.

  15. Characterization of water reservoirs affected by acid mine drainage: geochemical, mineralogical, and biological (diatoms) properties of the water.

    PubMed

    Valente, T; Rivera, M J; Almeida, S F P; Delgado, C; Gomes, P; Grande, J A; de la Torre, M L; Santisteban, M

    2016-04-01

    This work presents a combination of geochemical, mineralogical, and biological data obtained in water reservoirs located in one of the most paradigmatic mining regions, suffering from acid mine drainage (AMD) problems: the Iberian Pyrite Belt (IPB). Four water reservoirs located in the Spanish sector of the IBP, storing water for different purposes, were selected to achieve an environmental classification based on the effects of AMD: two mining dams (Gossan and Águas Ácidas), a reservoir for industrial use (Sancho), and one with water used for human supply (Andévalo). The results indicated that the four reservoirs are subject to the effect of metallic loads from polluted rivers, although with different levels: Águas Ácidas > Gossan > Sancho ≥ Andévalo. In accordance, epipsammic diatom communities have differences in the respective composition and dominant taxa. The dominant diatoms in each reservoir indicated acid water: Pinnularia acidophila and Pinnularia aljustrelica were found in the most acidic dams (Gossan and Águas Ácidas, with pH <3), Pinnularia subcapitata in Sancho (pH 2.48-5.82), and Eunotia exigua in Andévalo (pH 2.34-6.15). PMID:26032451

  16. Whole-genome sequencing of Bacillus subtilis XF-1 reveals mechanisms for biological control and multiple beneficial properties in plants.

    PubMed

    Guo, Shengye; Li, Xingyu; He, Pengfei; Ho, Honhing; Wu, Yixin; He, Yueqiu

    2015-06-01

    Bacillus subtilis XF-1 is a gram-positive, plant-associated bacterium that stimulates plant growth and produces secondary metabolites that suppress soil-borne plant pathogens. In particular, it is especially highly efficient at controlling the clubroot disease of cruciferous crops. Its 4,061,186-bp genome contains an estimated 3853 protein-coding sequences and the 1155 genes of XF-1 are present in most genome-sequenced Bacillus strains: 3757 genes in B. subtilis 168, and 1164 in B. amyloliquefaciens FZB42. Analysis using the Cluster of Orthologous Groups database of proteins shows that 60 genes control bacterial mobility, 221 genes are related to cell wall and membrane biosynthesis, and more than 112 are genes associated with secondary metabolites. In addition, the genes contributed to the strain's plant colonization, bio-control and stimulation of plant growth. Sequencing of the genome is a fundamental step for developing a desired strain to serve as an efficient biological control agent and plant growth stimulator. Similar to other members of the taxon, XF-1 has a genome that contains giant gene clusters for the non-ribosomal synthesis of antifungal lipopeptides (surfactin and fengycin), the polyketides (macrolactin and bacillaene), the siderophore bacillibactin, and the dipeptide bacilysin. There are two synthesis pathways for volatile growth-promoting compounds. The expression of biosynthesized antibiotic peptides in XF-1 was revealed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. PMID:25860123

  17. Interaction of acylated and substituted antimicrobial peptide analogs with phospholipid-polydiacetylene vesicles. Correlation with their biological properties.

    PubMed

    Siano, Alvaro; Húmpola, María V; Rey, María C; Simonetta, Arturo; Tonarelli, Georgina G

    2011-07-01

    A series of peptide analogs based on region 6-22 of Plantaricin 149 sequence were synthesized. The interaction between these analogs and phospholipid-polydiacetylene vesicles was investigated to evaluate the ability of the bioassay to detect differences in the interaction of the peptides with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine vesicles, associated with amino acid substitution and N-terminal conjugation of the sequences with short fatty acids (8 and 12 carbon atoms). Fatty acid conjugation of peptides with low antimicrobial activity resulted in lipopeptides with improved activity against strains of Staphylococcus aureus and Listeria monocytogenes. The length of the fatty acid determined the bacterial specificity, and the conjugation with n-octanoic acid yielded the most active analog (C8-CT) against Staphylococcus aureus strain (MIC: 1.0 μm) while the conjugation with n-dodecanoic acid (C12-CT) was optimal for Listeria monocytogenes strain (MIC: 2.0 μm). In contrast, the substitution of Phe by Trp had an unfavorable effect on the antimicrobial activity. Hemolysis tests and membrane interaction studies with dipalmitoylphosphatidylcholine-polydiacetylene vesicles showed that lipopeptides interact to a greater extent with both biological and biomimetic membranes. Also, a good correlation was found between antimicrobial activity against Staphylococcus aureus strain and % colorimetric response values with dipalmitoylphosphatidylglycerol-polydiacetylene vesicles. PMID:21496212

  18. Evaluation of mechanical properties and biological response of an alumina-forming Ni-free ferritic alloy.

    PubMed

    González-Carrasco, J L; Ciapetti, G; Montealegre, M A; Pagani, S; Chao, J; Baldini, N

    2005-06-01

    PM 2000 is a Ni-free oxide dispersion strengthened Fe-20Cr-5Al alloy able to develop a fine, dense and tightly adherent alpha-alumina scale during high-temperature oxidation. Despite the high temperature involved during thermal oxidation (1100 degrees C), microstructural changes in the candidate material, a hot rolled product, hardly occurs. Consequently, the good mechanical properties of the as-received material are not significantly affected. Moreover, due to the high compressive residual stresses at the alumina scale, an increase in the fatigue limit from 500 to 530 MPa is observed. Such stresses also account for the high capability of the coating/metal system to withstand more than 1% tensile deformation without cracking. The biocompatibility of the alloy was assessed in comparison to commercial alumina. Saos-2 osteoblast-like cells were either challenged with PM 2000 particles, or seeded onto PM 2000 (with and without scale) solid samples. Viability, growth, and ALP release from cells were assessed after 3 or 7 days, while mineralization was checked at 18 days. This study has demonstrated that PM 2000 with and without scale are capable of supporting in vitro growth and function of osteoblast-like cells over a period of 18 days. Results from this study suggest that the resulting alumina/alloy system combines the good mechanical properties of the alloy with the superior biocompatibility of the alpha-alumina, for which there is very good clinical experience. PMID:15626434

  19. Variation in the biological properties of HIV-1 R5 envelopes: implications of envelope structure, transmission and pathogenesis

    PubMed Central

    Duenas-Decamp, Maria José; Peters, Paul J; Repik, Alexander; Musich, Thomas; Gonzalez-Perez, Maria Paz; Caron, Catherine; Brown, Richard; Ball, Jonathan; Clapham, Paul R

    2010-01-01

    HIV-1 R5 viruses predominantly use CCR5 as a coreceptor to infect CD4+ T cells and macrophages. While R5 viruses generally infect CD4+ T cells, research over the past few years has demonstrated that they vary extensively in their capacity to infect macrophages. Thus, R5 variants that are highly macrophage tropic have been detected in late disease and are prominent in brain tissue of subjects with neurological complications. Other R5 variants that are less sensitive to CCR5 antagonists and use CCR5 differently have also been identified in late disease. These latter variants have faster replication kinetics and may contribute to CD4 T-cell depletion. In addition, R5 viruses are highly variable in many other properties, including sensitivity to neutralizing antibodies and inhibitors that block HIV-1 entry into cells. Here, we review what is currently known about how HIV-1 R5 viruses vary in cell tropism and other properties, and discuss the implications of this variation on transmission, pathogenesis, therapy and vaccines. PMID:20930940

  20. Development of a compact terahertz time-domain spectrometer for the measurement of the optical properties of biological tissues

    NASA Astrophysics Data System (ADS)

    Wilmink, Gerald J.; Ibey, Bennett L.; Tongue, Thomas; Schulkin, Brian; Laman, Norman; Peralta, Xomalin G.; Roth, Caleb C.; Cerna, Cesario Z.; Rivest, Benjamin D.; Grundt, Jessica E.; Roach, William P.

    2011-04-01

    Terahertz spectrometers and imaging systems are currently being evaluated as biomedical tools for skin burn assessment. These systems show promise, but due to their size and weight, they have restricted portability, and are impractical for military and battlefield settings where space is limited. In this study, we developed and tested the performance of a compact, light, and portable THz time-domain spectroscopy (THz-TDS) device. Optical properties were collected with this system from 0.1 to 1.6 THz for water, ethanol, and several ex vivo porcine tissues (muscle, adipose, skin). For all samples tested, we found that the index of refraction (n) decreases with frequency, while the absorption coefficient (μa) increases with frequency. Muscle, adipose, and frozen/thawed skin samples exhibited comparable n values ranging between 2.5 and 2.0, whereas the n values for freshly harvested skin were roughly 40% lower. Additionally, we found that the freshly harvested samples exhibited higher μa values than the frozen/thawed skin samples. Overall, for all liquids and tissues tested, we found that our system measured optical property values that were consistent with those reported in the literature. These results suggest that our compact THz spectrometer performed comparable to its larger counterparts, and therefore may be a useful and practical tool for skin health assessment.

  1. Improvement of mechanical and biological properties of TiNi alloys by addition of Cu and Co to orthodontic archwires.

    PubMed

    Phukaoluan, Aphinan; Khantachawana, Anak; Kaewtatip, Pongpan; Dechkunakorn, Surachai; Kajornchaiyakul, Julathep

    2016-09-01

    The purpose of this study was to investigate improved performances of TiNi in order to promote tooth movement. Special attention was paid to the effect on the clinical properties of TiNi of adding Cu and Co to this alloy. Ti49.4Ni50.6, Ti49Ni46Cu5 and Ti50Ni47Co3 (at %) alloys were prepared. Specimens were cold-rolled at 30% reduction and heat-treated at 400°C for 60min. Then, the test results were compared with two types of commercial archwires. The findings showed that superelasticity properties were confirmed in the manufactured commercial alloys at mouth temperature. The difference of stress plateau in TiNi, TiNiCo and commercial wires B at 25°C changed significantly at various testing temperatures due to the combination of martensite and austenite phases. At certain temperatures the alloys exhibited zero recovery stress at 2% strain and consequently produced zero activation force for moving teeth. The corrosion test showed that the addition of Cu and Co to TiNi alloys generates an increase in corrosion potential (Ecorr) and corrosion current densities (Icorr). Finally, we observed that addition of Cu and Co improved cell viability. We conclude that addition of an appropriate amount of a third alloying element can help enhance the performances of TiNi orthodontic archwires. PMID:27520713

  2. Degradation and biological properties of Ca-P contained micro-arc oxidation self-sealing coating on pure magnesium for bone fixation

    PubMed Central

    Wang, Weidan; Wan, Peng; Liu, Chen; Tan, Lili; Li, Weirong; Li, Lugee; Yang, Ke

    2015-01-01

    Poor corrosion resistance is one of the main disadvantages for biodegradable magnesium-based metals, especially applied for bone fixation, where there is a high demand of bio-mechanical strength and stability. Surface coating has been proved as an effective method to control the in vivo degradation. In this study a Ca-P self-sealing micro-arc oxidation (MAO) coating was studied to verify its efficacy and biological properties by in vitro and in vivo tests. It was found that the MAO coating could effectively retard the degradation according to immersion and electrochemical tests as well as 3D reconstruction by X-ray tomography after implantation. The MAO coating exhibited no toxicity and could stimulate the new bone formation. Therefore, the Ca-P self-sealing MAO coating could be a potential candidate for application of biodegradable Mg-based implant in bone fixations. PMID:26816635

  3. Structure-property relationships of a class of carbamate-based Fatty Acid Amide Hydrolase (FAAH) inhibitors: chemical and biological stability

    PubMed Central

    Vacondio, Federica; Silva, Claudia; Lodola, Alessio; Fioni, Alessandro; Rivara, Silvia; Duranti, Andrea; Tontini, Andrea; Sanchini, Silvano; Clapper, Jason; Piomelli, Daniele; Tarzia, Giorgio

    2012-01-01

    Cyclohexylcarbamic acid aryl esters are a class of Fatty Acid Amide Hydrolase (FAAH) inhibitors, which includes the reference compound URB597. The reactivity of their carbamate fragment is involved in pharmacological activity and may affect pharmacokinetic and toxicological properties. We conducted in vitro stability experiments in chemical and biological environments to investigate the structure-stability relationships in this class of compounds. The results show that electrophilicity of the carbamate influences its chemical stability, as suggested by the relation between the rate constant of alkaline hydrolysis (log kpH9) and the energy of lowest unoccupied molecular orbital (LUMO). Introduction of small, electron donor substituents at conjugated positions of the O-aryl moiety increased overall hydrolytic stability of the carbamate group without affecting FAAH inhibitory potency, whereas peripheral nonconjugated hydrophilic groups, which favor FAAH recognition, helped reducing oxidative metabolism in the liver. PMID:19554599

  4. [BIOLOGICAL PROPERTIES OF BACTERIA OF THE FAMILY ENTEROBACTERIACEAE AS COMPONENTS OF MICROSYMBIOCENOSIS OF THE FIRST INTERMEDIATE HOSTS OF O.FELINEUS].

    PubMed

    Stepanova, T F; Bukharin, O V; Kataeva, L V; Perunova, N B; Karpukhina, N F

    2015-01-01

    The objective of the investigation was to study the biological properties (antilysozyme activity (ALA), biofilm formation (BFF), and virulence factors) of different Enterobacteriaceae species isolated from Bithyniidae mollusks and their habitats. A total of 117 strains isolated from Bithyniidae mollusks of the genera Codiella and Bithynia and those from their habitats were the material to be studied. Thus, comparison of the mean values of ALA in Enterobacteriaceae species suggests that the strains isolated from the mollusks and their aqueous habitat did not virtually differ in this indicator. Also, there were no statistically significant differences in the detection rate of the Enterobacteriaceae strains having a pronounced antilysozyme activity and in that of mollusks circulating in the aqueous habitat when compared with the strains isolated from the mollusks. Comparison of BFF in the aqueous bacterial strains and mollusk microbiota representatives revealed the highest values in the former; just lower value was noted in the latter. Soil Enterobacteriaceae isolates had very low BFF values. PMID:26827577

  5. Effect of non-steroidal anti-inflammatory drugs on biological properties of Acanthamoeba castellanii belonging to the T4 genotype.

    PubMed

    Siddiqui, Ruqaiyyah; Lakhundi, Sahreena; Iqbal, Junaid; Khan, Naveed Ahmed

    2016-09-01

    Non-steroidal anti-inflammatory drug, Diclofenac, targeting COX have shown promise in the treatment of Acanthamoeba keratitis, but the underlying mechanisms remain unknown. Using various NSAIDs, Diclofenac sodium, Indomethacin, and Acetaminophen, here we determined the effects of NSAIDs on the biological properties of Acanthamoeba castellanii belonging to the T4 genotype. Using amoebicidal assays, the results revealed that Diclofenac sodium, and Indomethacin affected growth of A. castellanii. In contrast, none of the compounds tested had any effect on the viability of A. castellanii. Importantly, all NSAIDs tested abolished A. castellanii encystation. This is a significant finding as the ability of amoebae to transform into the dormant cyst form presents a significant challenge in the successful treatment of infection. The NSAIDs inhibit production of cyclo-oxegenase, which regulates the synthesis of prostaglandins suggesting that cyclooxygenases (COX-1 and COX-2) and prostaglandins play significant role(s) in Acanthamoeba biology. As NSAIDs are routinely used in the clinical practice, these findings may help design improved preventative strategies and/or of therapeutic value to improve prognosis, when used in combination with other anti-amoebic drugs. PMID:27381503

  6. Influence of powdered activated carbon addition on water quality, sludge properties, and microbial characteristics in the biological treatment of commingled industrial wastewater.

    PubMed

    Hu, Qing-Yuan; Li, Meng; Wang, Can; Ji, Min

    2015-09-15

    A powdered activated carbon-activated sludge (PAC-AS) system, a traditional activated sludge (AS) system, and a powdered activated carbon (PAC) system were operated to examine the insights into the influence of PAC addition on biological treatment. The average COD removal efficiencies of the PAC-AS system (39%) were nearly double that of the AS system (20%). Compared with the average efficiencies of the PAC system (7%), COD removal by biodegradation in the PAC-AS system was remarkably higher than that in the AS system. The analysis of the influence of PAC on water quality and sludge properties showed that PAC facilitated the removal of hydrophobic matter and metabolic acidic products, and also enhanced the biomass accumulation, sludge settleability, and specific oxygen uptake rate inside the biological system. The microbial community structures in the PAC-AS and AS systems were monitored. The results showed that the average well color development in the PAC-AS system was higher than that in the AS system. The utilization of various substrates by microorganisms in the two systems did not differ. The dissimilarity index was far less than one; thus, showing that the microbial community structures of the two systems were the same. PMID:25863578

  7. Evaluation, prediction and optimization the ultrasound-assisted extraction method using response surface methodology: antioxidant and biological properties of Stachys parviflora L.

    PubMed Central

    Bashi, Davoud Salar; Dowom, Samaneh Attaran; Bazzaz, Bibi Sedigheh Fazly; Khanzadeh, Farhad; Soheili, Vahid; Mohammadpour, Ali

    2016-01-01

    Objective(s): To optimize the extraction method using response surface methodology, extract the phenolic compounds, and identify the antioxidant and biological properties of Stachys parviflora L. extracts. Materials and Methods: Maceration and ultrasound-assisted extraction (UAE) (4, 7, 10 min treatment time, 40, 70, 100 % high-intensity and 60, 80, 100 % (v v-1) methanol purity) were applied to obtain the extracts. SEM was conducted to provide the microstructure of the extracted plant. MICs (colorimetric assay), MFCs (colony diameter), total phenolic content, total flavonoid content, radical scavenging capacity and extraction efficiency were determined. HPLC analysis was applied to measure the existent phenolic compounds. Results: A quadratic model (4 min treatment time, 74.5 % high-intensity and 74.2 % solvent purity) was suggested as the best (TPC: 20.89 mg GAE g-1 d.m., TFC: 6.22 mg QEs g-1 d.m., DPPH IC50: 21.86 µg ml-1 and EE: 113.65 mg g-1 d.m.) UAE extraction model. The optimized UAE extract was generally more effective against Gram-positive microorganisms (MIC: 10-20; MBC: 10-40 (mg ml-1)) than Gram-negative ones (MIC: 40; MBC: >40 (mg ml-1)). Moreover, it (MGI: 2.32-100 %) revealed more anti-mold activity than maceration (MGI: <28.77 %). Explosive disruption of the cell walls, therefore, enhanced extraction yield by acoustic cavitation, was elucidated using SEM. Caffeic acid, tannic acid, quercetin, trans ferulic acid and rosmarinic acid were determined as the phenolic compounds in the optimized extract. Conclusion: RSM optimization was successfully applied for UAE from S. parviflora. The considerable antioxidant and biological properties were attributed to the phenolic compounds. PMID:27403260

  8. Synthesis, molecular properties, toxicity and biological evaluation of some new substituted imidazolidine derivatives in search of potent anti-inflammatory agents.

    PubMed

    Husain, Asif; Ahmad, Aftab; Khan, Shah Alam; Asif, Mohd; Bhutani, Rubina; Al-Abbasi, Fahad A

    2016-01-01

    The aim of this study was to design and synthesize pharmaceutical agents containing imidazolidine heterocyclic ring in the hope of developing potent, safe and orally active anti-inflammatory agents. A number of substituted-imidazolidine derivatives (3a-k) were synthesized starting from ethylene diamine and aromatic aldehydes. The imidazolidine derivatives (3a-k) were investigated for their anticipated anti-inflammatory, and analgesic activity in Wistar albino rats and Swiss albino mice, respectively. Bioactivity score, molecular and pharmacokinetic properties of the imidazolidine derivatives were calculated by online computer software programs viz. Molinspiration and Osiris property explorer. The results of biological testing indicated that among the synthesized compounds only three imidazolidine derivatives namely 4-[1,3-Bis(2,6-dichlorobenzyl)-2-imidazolidinyl]phenyl-diethylamine (3g), 4-[1,3-Bis(3-hydroxy-4-methoxybenzyl)-2-imidazolidinyl]phenyl-diethylamine (3i) and 4-(1,3-Bis(4-methoxybenzyl)-4-methylimidazolidin-2-yl)-phenyl-diethylamine (3j) possess promising anti-inflammatory and analgesic actions. Additionally these derivatives displayed superior GI safety profile (low severity index) with respect to the positive control, Indomethacin. All synthesized compounds showed promising bioactivity score for drug targets by Molinspiration software. Almost all the compounds were predicted to have very low toxicity risk by Osiris online software. Compound number (3i) emerged as a potential candidate for further research as it obeyed Lipinski's rule of five for drug likeness, exhibited promising biological activity in-vivo and showed no risk of toxicity in computer aided screening. PMID:26903774

  9. Evaluation of Biological Properties of Electron Beam Melted Ti6Al4V Implant with Biomimetic Coating In Vitro and In Vivo

    PubMed Central

    Wang, Cheng-Tao; Li, Guo-Chen; Lei, Wei; Zhang, Zhi-Yong; Wang, Lin

    2012-01-01

    Background High strength porous titanium implants are widely used for the reconstruction of craniofacial defects because of their similar mechanical properties to those of bone. The recent introduction of electron beam melting (EBM) technique allows a direct digitally enabled fabrication of patient specific porous titanium implants, whereas both their in vitro and in vivo biological performance need further investigation. Methods In the present study, we fabricated porous Ti6Al4V implants with controlled porous structure by EBM process, analyzed their mechanical properties, and conducted the surface modification with biomimetic approach. The bioactivities of EBM porous titanium in vitro and in vivo were evaluated between implants with and without biomimetic apatite coating. Results The physical property of the porous implants, containing the compressive strength being 163 - 286 MPa and the Young’s modulus being 14.5–38.5 GPa, is similar to cortical bone. The in vitro culture of osteoblasts on the porous Ti6Al4V implants has shown a favorable circumstance for cell attachment and proliferation as well as cell morphology and spreading, which were comparable with the implants coating with bone-like apatite. In vivo, histological analysis has obtained a rapid ingrowth of bone tissue from calvarial margins toward the center of bone defect in 12 weeks. We observed similar increasing rate of bone ingrowth and percentage of bone formation within coated and uncoated implants, all of which achieved a successful bridging of the defect in 12 weeks after the implantation. Conclusions This study demonstrated that the EBM porous Ti6Al4V implant not only reduced the stress-shielding but also exerted appropriate osteoconductive properties, as well as the apatite coated group. The results opened up the possibility of using purely porous titanium alloy scaffolds to reconstruct specific bone defects in the maxillofacial and orthopedic fields. PMID:23272208

  10. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO.

    PubMed

    Kim, Dong-Ae; Abo-Mosallam, Hany; Lee, Hye-Young; Lee, Jung-Hwan; Kim, Hae-Won; Lee, Hae-Hyoung

    2015-01-01

    Some weaknesses of conventional glass ionomer cement (GIC) as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved.Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements.Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol%) of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitrorat dental pulp stem cells (rDPSCs) viability were examined for the prepared GICs and compared to a commercial GIC.Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min) specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05) and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs.Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials. PMID:26398508

  11. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO

    PubMed Central

    Dong-Ae, KIM; Hany, ABO-MOSALLAM; Hye-Young, LEE; Jung-Hwan, LEE; Hae-Won, KIM; Hae-Hyoung, LEE

    2015-01-01

    Some weaknesses of conventional glass ionomer cement (GIC) as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved. Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements. Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol%) of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitro rat dental pulp stem cells (rDPSCs) viability were examined for the prepared GICs and compared to a commercial GIC. Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min) specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05) and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs. Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials. PMID:26398508

  12. New series of aromatic/ five-membered heteroaromatic butanesulfonyl hydrazones as potent biological agents: Synthesis, physicochemical and electronic properties

    NASA Astrophysics Data System (ADS)

    Hamurcu, Fatma; Mamaş, Serhat; Ozdemir, Ummuhan Ozmen; Gündüzalp, Ayla Balaban; Senturk, Ozan Sanlı

    2016-08-01

    The aromatic/five-membered heteroaromatic butanesulfonylhydrazone derivatives; 5-bromosalicylaldehydebutanesulfonylhydrazone(1), 2-hydroxy-1-naphthaldehydebutane sulfonylhydrazone(2), indole-3-carboxaldehydebutanesulfonylhydrazone (3), 2-acetylfuran- carboxyaldehydebutanesulfonylhydrazone(4), 2-acetylthiophenecarboxyaldehydebutane- sulfonylhydrazone(5) and 2-acetyl-5-chlorothiophenecarboxyaldehydebutanesulfonyl hydrazone (6) were synthesized by the reaction of butane sulfonic acid hydrazide with aldehydes/ketones and characterized by using elemental analysis, 1H NMR, 13C NMR and FT-IR technique. Their geometric parameters and electronic properties consist of global reactivity descriptors were also determined by theoretical methods. The electrochemical behavior of the butanesulfonylhydrazones were investigated by using cyclic voltammetry (CV), controlled potential electrolysis and chronoamperometry (CA) techniques. The number of electrons transferred (n), diffusion coefficient (D) and standard heterogeneous rate constants (ks) were determined by electrochemical methods.

  13. Microencapsulation of new probiotic formulations for gastrointestinal delivery: in vitro study to assess viability and biological properties.

    PubMed

    D'Orazio, G; Di Gennaro, P; Boccarusso, M; Presti, I; Bizzaro, G; Giardina, S; Michelotti, A; Labra, M; La Ferla, B

    2015-11-01

    The paper describes the preparation of new probiotic formulations based on chitosan-coated alginate microcapsules containing three different probiotic strains, Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070, and Bifidobacterium animalis subsp. lactis PBS075 taken individually and as a mixture of them. The effects of microencapsulation on the viability of the strains in conditions simulating the gastrointestinal tract and under industrial processes conditions were studied. In addition, an evaluation of their probiotic properties was also investigated by in vitro tests on the human intestinal cell line HT-29 to explore the effect of microencapsulation on health beneficial effect of the considered strains. Non-encapsulated cells were completely destroyed when exposed to simulated gastric juice and other stress conditions, while encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice and heat and osmotic treatment. Moreover, in this study, the effect of the various microencapsulated probiotic strain formulations was compared with analogous formulations also containing the β-glucan Pleuran. The microencapsulation effectively protected the selected bacteria, as single strain and as a mixture of the three strains in both the formulations with and without Pleuran, from simulating gastrointestinal tract and industrial process conditions in delivering the viable cells without any significant adverse effect on their functionalities. The comparative study of the immunomodulatory properties of each single strain and the mixture of the three strains revealed a synergistic effect of the probiotic mixture, but no appreciable difference between the two kinds of formulations could be detected, as the effect of Pleuran is covered by the higher potential of the probiotic strains. PMID:26239070

  14. The evaluation of the impact of titania nanotube covers morphology and crystal phase on their biological properties.

    PubMed

    Lewandowska, Żaneta; Piszczek, Piotr; Radtke, Aleksandra; Jędrzejewski, Tomasz; Kozak, Wiesław; Sadowska, Beata

    2015-04-01

    The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties. Cellular functionality were investigated for up to 3 days in culture using a cell viability assay and scanning electron microscopy. In general, results of our studies revealed that fibroblasts adhesion, proliferation, and differentiation on the titania nanotube coatings is clearly higher than on the surface of the pure titanium foil. The formation of crystallic islands in the nanotubes structure induced a significant acceleration in the growth rate of fibroblasts cells by as much as ~200 %. Additionally, some types of TiO2 layers revealed the ability to the reduce of the staphylococcal aggregates/biofilm formation. The nanotube coatings formed during the anodization process using the voltage 4 V proved to be the stronger S. aureus aggregates/biofilm inhibitor in comparison to the uncovered titanium substrate. That accelerated eukaryotic cell growth and anti-biofilm activity is believed to be advantageous for faster cure of dental and orthopaedic patients, and also for a variety of biomedical diagnostic and therapeutic applications. The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties. PMID:25791457

  15. Examination of surface properties and in vitro biological performance of amorphous diamond-like carbon-coated polyurethane.

    PubMed

    Jones, David S; Garvin, Clare P; Dowling, Denis; Donnelly, Kevin; Gorman, Sean P

    2006-08-01

    Despite the emerging use of diamond-like carbon (DLC) as a coating for medical devices, few studies have examined the resistance of DLC coatings onto medical polymers to both microbial adherence and encrustation. In this study, amorphous DLC of a range of refractive indexes (1.7-1.9) and thicknesses (100-600 nm) was deposited onto polyurethane, a model polymer, and the resistance to microbial adherence (Escherichia coli; clinical isolate) and encrustation examined using in vitro models. In comparison to the native polymer, the advancing and receding contact angles of DLC-coated polyurethane were lower, indicating greater hydrophilic properties. No relationship was observed between refractive index, thickness, and advancing contact angle, as determined using multiple correlation analysis. The resistances of the various DLC-coated polyurethane films to encrustation and microbial adherence were significantly greater than that to polyurethane; however, there were individual differences between the resistances of the various DLC coatings. In general, increasing the refractive index of the coatings (100 nm thickness) decreased the resistance of the films to both hydroxyapatite and struvite encrustation and to microbial adherence. Films of lower thicknesses (100 and 200 nm; of defined refractive index, 1.8), exhibited the greatest resistance to encrustation and to microbial adherence. In conclusion, this study has uniquely illustrated both the microbial antiadherence properties and resistance to urinary encrustation of DLC-coated polyurethane. The resistances to encrustation and microbial adherence were substantial, and in light of this, it is suggested that DLC coatings of low thickness and refractive index show particular promise as coatings of polymeric medical devices. PMID:16615067

  16. Scaling Properties of Biologically Active Scalar Concentration Fluctuations in the Atmospheric Surface Layer over a Managed Peatland

    NASA Astrophysics Data System (ADS)

    Detto, Matteo; Baldocchi, Dennis; Katul, Gabriel G.

    2010-09-01

    The higher-order scalar concentration fluctuation properties are examined in the context of Monin-Obukhov similarity theory for a variety of greenhouse gases that have distinct and separate source/sink locations along an otherwise ideal micrometeorological field site. Air temperature and concentrations of water vapour, carbon dioxide and methane were measured at high frequency (10 Hz) above a flat and extensive peat-land soil in the San Joaquin-Sacramento Delta (California, USA) area, subjected to year-round grazing by beef cattle. Because of the heterogeneous distribution of the sources and sinks of CO2 and especially CH4 emitted by cattle, the scaling behaviour of the higher-order statistical properties diverged from predictions based on a balance between their production and dissipation rate terms, which can obtained for temperature and H2O during stationary conditions. We identify and label these departures as ‘exogenous’ because they depend on heterogeneities and non-stationarities induced by boundary conditions on the flow. Spectral analysis revealed that the exogenous effects show their signatures in regions with frequencies lower than those associated with scalar vertical transport by turbulence, though the two regions may partially overlap in some cases. Cospectra of vertical fluxes appear less influenced by these exogenous effects because of the modulating role of the vertical velocity at low frequencies. Finally, under certain conditions, the presence of such exogenous factors in higher-order scalar fluctuation statistics may be ‘fingerprinted’ by a large storage term in the mean scalar budget.

  17. Porous vitalium-base nano-composite for bone replacement: Fabrication, mechanical, and in vitro biological properties.

    PubMed

    Dehaghani, Majid Taghian; Ahmadian, Mehdi

    2016-04-01

    Porous nano-composites were successfully prepared on addition of 58S bioactive glass to Co-base alloy with porosities of 37.2-58.8% by the combination of milling, space-holder and powder metallurgy techniques. The results of X-ray diffraction analysis showed that induced strain during milling of the Co-base alloy powder and also isothermal heat treatment during sintering process led to HCP↔FCC phase transformation which affected mechanical properties of the samples during compression test. Field emission scanning electron microscopy images showed that despite the remaining 58S powder in nanometer size in the composite, there were micro-particles due to sintering at high temperature which led to two different apatite morphologies after immersion in simulated body fluid. Calculated elastic modulus and 0.2% proof strength from stress-strain curves of compression tests were in the range of 2.2-8.3GPa and 34-198MPa, respectively. In particular, the mechanical properties of sample with 37.2% were found to be similar to those of human cortical bone. Apatite formation which was identified by scanning electron microscopy (SEM), pH meter and Fourier-transform infrared spectroscopy (FTIR) analysis showed that it could successfully convert bioinert Co-base alloy to bioactive type by adding 58S bioglass nano-particles. SEM images of cell cultured on the porous nano-composite with 37.2% porosity showed that cells properly grew on the surface and inside the micro and macro-pores. PMID:26874088

  18. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.; Johnson, Margaret M.

    This chapter deals with 1981 cases involving disputes over property. Cases involving the detachment and attachment of land continue to dominate the property chapter with 11 cases reported, the same number summarized in last year's chapter. One case involving school board referenda raised the interesting question of whether or not a state could…

  19. Property.

    ERIC Educational Resources Information Center

    Bickel, Robert D.; Zeller, Trisha A.

    A number of cases related to property issues involving institutions of higher education are examined in this chapter. Cases discussed touch on such topics as funding for property and equipment acquisition; opposition to building construction or demolition; zoning issues; building construction and equipment contracts; and lease agreements. Current…

  20. Property.

    ERIC Educational Resources Information Center

    Goldblatt, Steven M.; Piele, Philip K.

    This chapter reviews 1982 cases related to school property. Cases involving citizen efforts to overturn school board decisions to close schools dominate the property chapter, and courts continue to uphold school board authority to close schools, transfer students, and sell or lease the buildings. Ten cases involving detachment and attachment of…

  1. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Chapter 7 of a book on school law, this chapter deals with 1979 cases involving disputes over property. Cases involving taxpayer attempts to prevent the construction of school buildings dominate this year's property chapter, as they did last year's. Yet, paradoxically, there is also a significant increase in cases in which taxpayers tried to…

  2. Complete nucleotide sequence, genome organization, and biological properties of human immunodeficiency virus type 1 in vivo: evidence for limited defectiveness and complementation.

    PubMed Central

    Li, Y; Hui, H; Burgess, C J; Price, R W; Sharp, P M; Hahn, B H; Shaw, G M

    1992-01-01

    Previous studies of the genetic and biologic characteristics of human immunodeficiency virus type 1 (HIV-1) have by necessity used tissue culture-derived virus. We recently reported the molecular cloning of four full-length HIV-1 genomes directly from uncultured human brain tissue (Y. Li, J. C. Kappes, J. A. Conway, R. W. Price, G. M. Shaw, and B. H. Hahn, J. Virol. 65:3973-3985, 1991). In this report, we describe the biologic properties of these four clones and the complete nucleotide sequences and genome organization of two of them. Clones HIV-1YU-2 and HIV-1YU-10 were 9,174 and 9,176 nucleotides in length, differed by 0.26% in nucleotide sequence, and except for a frameshift mutation in the pol gene in HIV-1YU-10, contained open reading frames corresponding to 5'-gag-pol-vif-vpr-tat-rev-vpu-env-nef-3' flanked by long terminal repeats. HIV-1YU-2 was fully replication competent, while HIV-1YU-10 and two other clones, HIV-1YU-21 and HIV-1YU-32, were defective. All three defective clones, however, when transfected into Cos-1 cells in any pairwise combination, yielded virions that were replication competent and transmissible by cell-free passage. The cellular host range of HIV-1YU-2 was strictly limited to primary T lymphocytes and monocyte-macrophages, a property conferred by its external envelope glycoprotein. Phylogenetic analyses of HIV-1YU-2 gene sequences revealed this virus to be a member of the North American/European HIV-1 subgroup, with specific similarity to other monocyte-tropic viruses in its V3 envelope amino acid sequence. These results indicate that HIV-1 infection of brain is characterized by the persistence of mixtures of fully competent, minimally defective, and more substantially altered viral forms and that complementation among them is readily attainable. In addition, the limited degree of genotypic heterogeneity observed among HIV-1YU and other brain-derived viruses and their preferential tropism for monocyte-macrophages suggest that viral

  3. Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

    NASA Astrophysics Data System (ADS)

    Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

    2014-05-01

    One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

  4. Chemotherapy modulates the biological activity of breast cancer patients plasma: the protective properties of black chokeberry extract.

    PubMed

    Kędzierska, Magdalena; Malinowska, Joanna; Kontek, Bogdan; Kołodziejczyk-Czepas, Joanna; Czernek, Urszula; Potemski, Piotr; Piekarski, Janusz; Jeziorski, Arkadiusz; Olas, Beata

    2013-03-01

    In breast cancer patients (before and during anti-cancer therapy) oxidative/nitrative damage to various molecules is observed. Furthermore, anti-cancer treatments may also influence the hemostatic properties of blood platelets and plasma. The aim of our study was to assess the effect of oxidative/nitrative stress (estimated by measurements of the levels of carbonyl groups and 3-nitrotyrosine in proteins--ELISA and C-ELISA methods, respectively; lipid peroxidation and total antioxidant level--TAS) on the selected parameters of hemostatic activity of plasma (the process of fibrin polymerization and lysis) collected from breast cancer patients after surgery and after various phases of chemotherapy (doxorubicin and cyclophosphamide). Subsequently, we also evaluated the level of oxidative/nitrative stress and hemostatic activity in plasma from these patients in the presence of the commercial extract of Aronia melanocarpa (Aronox®) in vitro. Patients were hospitalized in Department of Oncological Surgery and Department of Chemotherapy in Medical University of Lodz, Poland. We observed increased levels of biomarkers of oxidative/nitrative stress in plasma from patients with breast cancer (before or after surgery and after various phases of chemotherapy) in comparison to healthy group. Our further experiments demonstrated the hemostatic activity of plasma from the investigated patients differs from hemostatic properties of plasma obtained from healthy volunteers. We also recognize the existence of a relationship between oxidative stress (measured by the level of carbonyl groups) and changes of hemostasis in breast cancer patients after I and IV phases of chemotherapy. Moreover, the obtained results showed that the commercial extract from A. melanocarpa berries significantly reduced, in in vitro system, the oxidative/nitrative stress and hemostasis changes in plasma from breast cancer patients, after surgery and different phases of chemotherapy. Considering the data

  5. Investigation of the biological and anti-cancer properties of ellagic acid-encapsulated nano-sized metalla-cages.

    PubMed

    Dubey, Abhishek; Park, Dae Won; Kwon, Jung Eun; Jeong, Yong Joon; Kim, Taegeun; Kim, Inhye; Kang, Se Chan; Chi, Ki-Whan

    2015-01-01

    Three new large hexanuclear metalla-prisms 9-11 incorporating 1,3, 5-tris(pyridin-4-ylethynyl)benzene (tpeb) 4 and one of the dinuclear arene ruthenium clips [Ru2(p-iPrC6H4Me)2(OO∩OO)][CF3SO3]2 (OO∩OO =2,5-dioxydo-1,4-benzoquinonato [dobq] 1, 5,8-dihydroxy-1,4-naphthaquinonato (donq) 2, and 6,11-dihydroxy-5,12-naphthacenedionato [dotq] 3), which encapsulate the guest molecule ellagic acid (2,3,7,8-tetrahydroxy-chromeno[5,4,3-cde]chromene-5,10-dione, 5) were prepared. All complexes were isolated as triflate salts in good yields and were fully characterized by (1)H NMR spectroscopy and electrospray ionization mass spectrometry. The photophysical properties of these metalla-prisms were also investigated. Compounds 9 and 10 showed potent antioxidant activity, but 10 had the superior ORACPE value (1.30 ± 0.020). Ellagic acid (5) and compound 11 showed weaker activity than that of Trolox. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that the metalla-prism compounds exhibit anticancer properties in vitro. Compound 10 inhibited the growth of all cancer cell lines at micromolar concentrations, with the highest cytotoxicity observed against A549 human lung cancer cells (IC50 =25.9 μM). However, these compounds had a lower anti-cancer activity than that of doxorubicin. In a tumoricidal assay, ellagic acid (5) and compound 10 induced cytotoxicity in tumor cells, while doxorubicin did not. While free ellagic acid had no effect on the granulocyte-colony stimulating factor and regulated on activation normal T cell expressed and secreted protein, the encapsulated metalla-prism 10 stimulated granulocyte-colony stimulating factor and reduced regulated on activation normal T cell expressed and secreted protein expression in the RAW264.7 macrophage line. Our results show that ellagic acid encapsulated in metalla-prisms inhibited cancer cells via the modulation of mRNA induction and protein expression levels of the granulocyte-colony stimulating

  6. Investigation of the biological and anti-cancer properties of ellagic acid-encapsulated nano-sized metalla-cages

    PubMed Central

    Dubey, Abhishek; Park, Dae Won; Kwon, Jung Eun; Jeong, Yong Joon; Kim, Taegeun; Kim, Inhye; Kang, Se Chan; Chi, Ki-Whan

    2015-01-01

    Three new large hexanuclear metalla-prisms 9–11 incorporating 1,3, 5-tris(pyridin-4-ylethynyl)benzene (tpeb) 4 and one of the dinuclear arene ruthenium clips [Ru2(p-iPrC6H4Me)2(OO∩OO)][CF3SO3]2 (OO∩OO =2,5-dioxydo-1,4-benzoquinonato [dobq] 1, 5,8-dihydroxy-1,4-naphthaquinonato (donq) 2, and 6,11-dihydroxy-5,12-naphthacenedionato [dotq] 3), which encapsulate the guest molecule ellagic acid (2,3,7,8-tetrahydroxy-chromeno[5,4,3-cde]chromene-5,10-dione, 5) were prepared. All complexes were isolated as triflate salts in good yields and were fully characterized by 1H NMR spectroscopy and electrospray ionization mass spectrometry. The photophysical properties of these metalla-prisms were also investigated. Compounds 9 and 10 showed potent antioxidant activity, but 10 had the superior ORACPE value (1.30±0.020). Ellagic acid (5) and compound 11 showed weaker activity than that of Trolox. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that the metalla-prism compounds exhibit anticancer properties in vitro. Compound 10 inhibited the growth of all cancer cell lines at micromolar concentrations, with the highest cytotoxicity observed against A549 human lung cancer cells (IC50 =25.9 μM). However, these compounds had a lower anti-cancer activity than that of doxorubicin. In a tumoricidal assay, ellagic acid (5) and compound 10 induced cytotoxicity in tumor cells, while doxorubicin did not. While free ellagic acid had no effect on the granulocyte-colony stimulating factor and regulated on activation normal T cell expressed and secreted protein, the encapsulated metalla-prism 10 stimulated granulocyte-colony stimulating factor and reduced regulated on activation normal T cell expressed and secreted protein expression in the RAW264.7 macrophage line. Our results show that ellagic acid encapsulated in metalla-prisms inhibited cancer cells via the modulation of mRNA induction and protein expression levels of the granulocyte-colony stimulating

  7. Systems cell biology

    PubMed Central

    Mast, Fred D.; Ratushny, Alexander V.

    2014-01-01

    Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology. PMID:25225336

  8. Effect of cooking and germination on phenolic composition and biological properties of dark beans (Phaseolus vulgaris L.).

    PubMed

    López, Ana; El-Naggar, Tarek; Dueñas, Montserrat; Ortega, Teresa; Estrella, Isabel; Hernández, Teresa; Gómez-Serranillos, M Pilar; Palomino, Olga M; Carretero, M Emilia

    2013-05-01

    Legumes are the basés diet in several countries. They hold a high nutritional value, but other properties related to human health are nowadays being studied. The aim of this work was to study the influence of processes (boiling or germination) on the phenolic composition of dark beans (Phaseolus vulgaris L. c.v. Tolosana) and their effect on their antioxidant, neuroprotective and anticancer ability. Phenolic composition of raw and processed dark beans was analysed by HPLC-PAD and HPLC-ESI/MS. The antioxidant activity was evaluated by ORAC. Astrocytes cultures (U-373) have been used to test their neuroprotective effect. Anticancer activities were evaluated on three different cell lines (renal adenocarcinoma (TK-10), breast adenocarcinoma (MCF-7) and melanoma (UACC-62)) by sulphorhodamine B method. Qualitative and quantitative differences in phenolic composition have been observed between raw and processed dark beans that influence the antioxidant activity, mainly for germinated samples which show a decrease of antioxidant capacity. Although every assayed extracts decreased reactive oxygen species release and exhibited cytotoxicity activities on cancer cell lines, raw beans proved to be the most active in neuroprotective and antitumoral effects; this sample is especially rich in phenolic compounds, mainly anthocyanins. This study further demonstrated that phenolic composition of dark beans is related with cooking process and so with their neuroprotective and anticancer activity; cooking of dark beans improves their digestion and absorption at intestinal level, while maintaining its protective ability on oxidative process at cellular level. PMID:23265523

  9. Fabrication of multi-walled carbon nanotube layers with selected properties via electrophoretic deposition: physicochemical and biological characterization

    NASA Astrophysics Data System (ADS)

    Benko, Aleksandra; Przekora, Agata; Wesełucha-Birczyńska, Aleksandra; Nocuń, Marek; Ginalska, Grażyna; Błażewicz, Marta

    2016-04-01

    The aim of the study was to fabricate and extensively characterize a layer of carbon nanotubes deposited on the surface of titanium, in order to prove that, by selecting proper type of carbon nanotubes and altering different parameters of the electrophoretic deposition process, we are able to obtain products having a different influence on cells—either favouring or inhibiting their survival. In the study, a novel mixture of solvents was used to suspend as-received tubes and then applied in the electrophoretic deposition. High charging capability and high yield of the obtained deposits are promising results when considering up-scaling the process. The surface of the obtained multi-walled carbon nanotubes-coated titanium samples was characterized using SEM, AFM, XPS and Raman microspectroscopy. The carbon nanotube layer showed nanorough topography and was formed of randomly and loosely distributed tubes, and XPS study revealed that there was a significant amount of C-O bonds. These properties were found to be favourable to osteoblast survival, spreading and growth.

  10. Using the plant vacuole as a biological system to investigate the functional properties of exogenous channels and transporters.

    PubMed

    Festa, M; Lagostena, L; Carpaneto, A

    2016-03-01

    Plant cells possess a large intracellular compartment that animal cells do not, the central vacuole, which has been investigated for a long time. The central vacuole can occupy up to 90% of the cellular volume and, differently from intracellular organelles from animal cells such as lysosomes or endosomes, it is easy to isolate. Because of its large dimension (up to 40μm diameter) it can be successfully studied using the classical patch-clamp technique. Following the idea that the vacuolar membrane could be used as a convenient model to characterize the functional properties of channel-forming peptides, we verified that the phytotoxic lipodepsipeptide Syringopeptin 25A from Pseudomonas syringae pv syringae was able to form ionic pores in sugar beet vacuoles and we performed a detailed biophysical analysis. Recently, we extended the use of plant vacuoles to the expression and functional characterization of animal intracellular transporters, namely rat CLC-7, and channels, i.e. human TPC2. Since endo-lysosomal transporters and channels are still largely unexplored, principally because their intracellular localization renders them difficult to study, we believe that this novel approach will prove to be a powerful system for the investigation of the molecular mechanisms of exogenous transporters and channels. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale. PMID:26431786

  11. Biological properties and therapeutic activities of honey in wound healing: A narrative review and meta-analysis.

    PubMed

    Oryan, Ahmad; Alemzadeh, Esmat; Moshiri, Ali

    2016-05-01

    For thousands of years, honey has been used for medicinal applications. The beneficial effects of honey, particularly its anti-microbial activity represent it as a useful option for management of various wounds. Honey contains major amounts of carbohydrates, lipids, amino acids, proteins, vitamin and minerals that have important roles in wound healing with minimum trauma during redressing. Because bees have different nutritional behavior and collect the nourishments from different and various plants, the produced honeys have different compositions. Thus different types of honey have different medicinal value leading to different effects on wound healing. This review clarifies the mechanisms and therapeutic properties of honey on wound healing. The mechanisms of action of honey in wound healing are majorly due to its hydrogen peroxide, high osmolality, acidity, non-peroxide factors, nitric oxide and phenols. Laboratory studies and clinical trials have shown that honey promotes autolytic debridement, stimulates growth of wound tissues and stimulates anti-inflammatory activities thus accelerates the wound healing processes. Compared with topical agents such as hydrofiber silver or silver sulfadiazine, honey is more effective in elimination of microbial contamination, reduction of wound area, promotion of re-epithelialization. In addition, honey improves the outcome of the wound healing by reducing the incidence and excessive scar formation. Therefore, application of honey can be an effective and economical approach in managing large and complicated wounds. PMID:26852154

  12. Effects of entrapment on nucleic acid content, cell morphology, cell surface property, and stress of pure cultures commonly found in biological wastewater treatment.

    PubMed

    Pramanik, Sudipta; Khanna, Rohit; Katti, Kalpana; McEvoy, John; Khan, Eakalak

    2011-10-01

    The effects of cell entrapment on nucleic acid content, cell morphology, cell surface property, and stress of major groups of bacteria (betaproteobacteria and gammaproteobacteria) in biological municipal wastewater treatment were investigated. Three different entrapment media (alginate, carrageenan, and polyvinyl alcohol) were examined. Results indicated that the entrapment and type of entrapment media affected nucleic acid content, cell morphology, cell surface property, and stress of the three representative species (Alcaligenes faecalis, Comamonas testosteroni, and Pseudomonas putida) studied. The highest deoxyribonucleic acid and ribonucleic acid increases were observed with the alginate and polyvinyl alcohol (PVA) entrapment, respectively. A cell morphological change from bacilli to coccoidal was observed in the case of alginate entrapment while the PVA-entrapped cells had a slim morphology when compared to non-entrapped cells and formed putative nanowires. The entrapment increased or decreased the surface roughness of cells depending on the type of entrapment media. Expression of a nitrosative stress gene, which is linked to oxygen deprivation, was observed more in the alginate-entrapped cells. These research findings advance the fundamental understanding of the entrapped cell physiology which can lead to more efficient entrapped cell-based wastewater treatment. PMID:21660542

  13. [Effects of understory removal and nitrogen addition on the soil chemical and biological properties of Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land].

    PubMed

    Lin, Gui-Gang; Zhao, Qiong; Zhao, Lei; Li, Hui-Chao; Zeng, De-Hui

    2012-05-01

    A full factorial experiment was conducted to study the effects of understory removal and nitrogen addition (8 g x m(-2)) on the soil NO(3-)-N and NH(4+)-N concentrations, potential net nitrogen mineralization rate (PNM) and nitrification rate (PNN), microbial biomass C (MBC) and N (MBN), MBC/MBN, urease and acid phosphomonoesterase activities, and Olsen-P concentration in a Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land during a growth season. Understory removal decreased the soil NH(4+)-N concentration, PNM, MBC, and MBN/MBN significantly, increased the soil Olsen-P concentration, but had little effects on the soil NO(3-)-N concentration, PNN, and urease and acid phosphomonoesterase activities. Nitrogen addition increased the soil NO(3-)-N concentration, PNM and PNN significantly, but had little effects on the other test properties. The interaction between understory removal and nitrogen addition had significant effects on the soil NH(4+)-N concentration, but little effects on the soil NO(3-)-N concentration. However, the soil NO(3-)-N concentration in the plots of understory removal with nitrogen addition was increased by 27%, compared with the plots of nitrogen addition alone, which might lead to the leaching of NO3-. It was suggested that understory vegetation could play an important role in affecting the soil chemical and biological properties in Mongolian pine plantations, and hence, the importance of understory vegetation should not be neglected when the forest management and restoration were implemented. PMID:22919826

  14. Comparison of biological properties of umbilical cord-derived mesenchymal stem cells from early and late passages: immunomodulatory ability is enhanced in aged cells.

    PubMed

    Zhuang, Yong; Li, Dong; Fu, Jinqiu; Shi, Qing; Lu, Yuanyuan; Ju, Xiuli

    2015-01-01

    Mesenchymal stem cells (MSCs) are a potential source of adult stem cells for cell-based therapeutics due to their substantial multilineage differentiation capacity and secretory functions. No information is presently available regarding the maintenance of immunosuppressive properties of this cell type with repeated passages. It was therefore the aim of the present study to analyze the biological properties, particularly the immunoregulatory effect, of MSCs from late passages. The differences between young and old MSCs in morphology, cell surface antigen phenotype, proliferation, gene expression and immunomodulatory ability were investigated. The results of the current study demonstrated that with the passage of cells, senescent MSCs displayed a characteristically enlarged and flattened morphology, different gene expression profiles and stronger immunosuppressive activities. Increased interleukin-6 production may be a possible underlying mechanism for this enhanced immunomodulatory ability of MSCs. These findings suggest that aged MSCs may provide a treatment option for patients with graft versus host disease and other diseases associated with dysregulation of the immune system. PMID:25339265

  15. Comparative assessment of structural and biological properties of biomimetically coated hydroxyapatite on alumina (alpha-Al2O3) and titanium (Ti-6Al-4V) alloy substrates.

    PubMed

    Kapoor, Renu; Sistla, Pavana Goury; Kumar, Jerald Mahesh; Raj, T Avinash; Srinivas, G; Chakraborty, Jui; Sinha, Mithlesh K; Basu, Debabrata; Pande, Gopal

    2010-09-01

    Previous reports have shown the use of hydroxyapatite (HAp) and related calcium phosphate coatings on metal and nonmetal substrates for preparing tissue-engineering scaffolds, especially for osteogenic differentiation. These studies have revealed that the structural properties of coated substrates are dependent significantly on the method and conditions used for coating and also whether the substrates had been modified prior to the coating. In this article, we have done a comparative evaluation of the structural features of the HAp coatings, prepared by using simulated body fluid (SBF) at 25 degrees C for various time periods, on a nonporous metal substrate titanium-aluminium-vanadium (Ti-6Al-4V) alloy and a bioinert ceramic substrate alpha-alumina (alpha-Al(2)O(3)), with and without their prior treatment with the globular protein bovine serum albumin (BSA). Our analysis of these substrates by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectrometry showed significant and consistent differences in the quantitative and qualitative properties of the coatings. Interestingly, the bioactivity of these substrates in terms of supporting in vitro cell adhesion and spreading, and in vivo effects of implanted substrates, showed a predictable pattern, thus indicating that some coated substrates prepared under our conditions could be more suitable for biological/biomedical applications. PMID:20730928

  16. Biological synthesis of silver nanoparticles from Adansonia digitata L. fruit pulp extract, characterization, and its antimicrobial properties

    PubMed Central

    Kumar, Chennareddy Maruthi Kesava; Yugandhar, Pulicherla; Savithramma, Nataru

    2016-01-01

    Aim: In the present study, we report a cost-effective, eco-friendly, and an efficient alternative method for large scale production of silver nanoparticles (AgNPs) from Adansonia digitata fruit pulp extract. The study mainly focused on the synthesis, characterization, and antimicrobial properties of AgNPs. Materials and Methods: Synthesis of AgNPs with the help of standard protocol and characterized by ultraviolet (UV)-vis spectrophotometry, Fourier transform infra-red (FTIR), X-ray diffractometer (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) with EDAX, transmission electron microscopy (TEM) and explore their potential growth inhibitory effect on 07 bacterial and 05 fungal pathogens. Results: The synthesized AgNPs are characterized by UV-vis spectrophotometry shows a broad peak at 434 nm. The FTIR spectroscopic analysis clearly reveals phenols and proteins are main responsible for reduction and stabilization of nanoparticles. XRD studies show the nanoparticles are crystalline in nature owing 44 nm in size. EDAX spectrum shows a 33.28 weight percentage of Ag metal in the reaction medium confirms the purity of AgNPs. High resolution and magnification studies with AFM, SEM, and TEM reveal the nanoparticles are polydispersed, spherical in shape, having the size range from 3 to 57 nm without any agglomeration between the particles. Further, the antimicrobial studies reveal the potentiality of nanoparticles against different microbial pathogens. Conclusion: The present study is mainly focused on the synthesis of AgNPs from A. digitata fruit pulp extract. Here, we succeed to synthesize a narrow range of particles and validate its potential antimicrobial activity on different microorganisms. Based on this, we conclude that A. digitata pulp extract is a good source toward the reduction of AgNPs and acts as environment benign antimicrobial agents. PMID:27069729

  17. Novel glycolipid TLR2 ligands of the type Pam2Cys-α-Gal: synthesis and biological properties.

    PubMed

    Thomann, Jean-Sébastien; Monneaux, Fanny; Creusat, Gaëlle; Spanedda, Maria Vittoria; Heurtault, Béatrice; Habermacher, Chloé; Schuber, Francis; Bourel-Bonnet, Line; Frisch, Benoît

    2012-05-01

    A more complete understanding of the mechanism of action of TLR agonists has fueled the investigation of new synthetic immunoadjuvants. In this context, we designed and synthesized glycolipids of the type Pam(2)Cys-α-Galactose as novel immunoadjuvants. Their synthesis required modifying a hydrophobic tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety, i.e. the minimal structure required for TLR2 agonist activity, by addition of a hydrophilic head, either an α-Galactosylpyranose or an α-Galactosylfuranose to gain respectively Pam(2)CGalp and Pam(2)CGalf. While preparing a carbohydrate building block, an unexpected stereoselectivity was observed during a halide ion-catalytic process on a protected galactofuranose: the alpha anomer was obtained with surprisingly high selectivity (α/β ratio>9) and with good isolated yield (51%). The TLR2 binding properties of Pam(2)CGalp and Pam(2)CGalf were then fully evaluated. Their efficiency in triggering the proliferation of BALB/c mouse splenocytes was also compared to that of Pam(2)CAG and Pam(3)CAG, two well-established ligands of TLRs. Moreover, the maturation state of murine dendritic cells previously incubated with either Pam(2)CGalp or Pam(2)CGalf was monitored by flow cytometry and compared to that induced by lipopolysaccharide. Pam(2)CGalp and Pam(2)CGalf were found to be equivalent TLR2 agonists, and induced splenocyte proliferation and DC maturation. With very similar activity, Pam(2)CGalp and Pam(2)CGalf were also 10-fold to 100-fold better than Pam(2)CAG and Pam(3)CAG at inducing B cell proliferation. This represents the first time a glucidic head has been added to the tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety whilst maintaining the immunomodulating activity. This should greatly enrich the data available on Pam(2)C structure/activity relationships. PMID:22483966

  18. Assessing the Biological Significance of Gene Expression Signatures and Co-Expression Modules by Studying Their Network Properties

    PubMed Central

    Minguez, Pablo; Dopazo, Joaquin

    2011-01-01

    Microarray experiments have been extensively used to define signatures, which are sets of genes that can be considered markers of experimental conditions (typically diseases). Paradoxically, in spite of the apparent functional role that might be attributed to such gene sets, signatures do not seem to be reproducible across experiments. Given the close relationship between function and protein interaction, network properties can be used to study to what extent signatures are composed of genes whose resulting proteins show a considerable level of interaction (and consequently a putative common functional role). We have analysed 618 signatures and 507 modules of co-expression in cancer looking for significant values of four main protein-protein interaction (PPI) network parameters: connection degree, cluster coefficient, betweenness and number of components. A total of 3904 gene ontology (GO) modules, 146 KEGG pathways, and 263 Biocarta pathways have been used as functional modules of reference. Co-expression modules found in microarray experiments display a high level of connectivity, similar to the one shown by conventional modules based on functional definitions (GO, KEGG and Biocarta). A general observation for all the classes studied is that the networks formed by the modules improve their topological parameters when an external protein is allowed to be introduced within the paths (up to the 70% of GO modules show network parameters beyond the random expectation). This fact suggests that functional definitions are incomplete and some genes might still be missing. Conversely, signatures are clearly not capturing the altered functions in the corresponding studies. This is probably because the way in which the genes have been selected in the signatures is too conservative. These results suggest that gene selection methods which take into account relationships among genes should be superior to methods that assume independence among genes outside their functional

  19. Synthesis, photoluminescence and biological properties of terbium(III) complexes with hydroxyketone and nitrogen containing heterocyclic ligands.

    PubMed

    Poonam; Kumar, Rajesh; Boora, Priti; Khatkar, Anurag; Khatkar, S P; Taxak, V B

    2016-01-01

    The ternary terbium(III) complexes [Tb(HDAP)3⋅biq], [Tb(HDAP)3⋅dmph] and [Tb(HDAP)3⋅bathophen] were prepared by using methoxy substituted hydroxyketone ligand HDAP (2-hydroxy-4,6-dimethoxyacetophenone) and an ancillary ligand 2,2-biquinoline or 5,6-dimethyl-1,10-phenanthroline or bathophenanthroline respectively. The ligand and synthesized complexes were characterised based on elemental analysis, FT-IR and (1)H NMR. Thermal behaviour of the synthesized complexes illustrates the general decomposition patterns of the complexes by thermogravimetric analysis. Photophysical properties such as excitation spectra, emission spectra and luminescence decay curves of the complexes were investigated in detail. The main green emitting peak at 548nm can be attributed to (5)D4→(7)F5 of Tb(3+) ion. Thus, these complexes might be used to make a bright green light-emitting diode for display purpose. In addition the in vitro antibacterial activities of HDAP and its Tb(III) complexes against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and antifungal activities against Candida albicans and Aspergillus niger are reported. The Tb(3+) complexes were found to be more potent antimicrobial agent as compared to the ligand. Among all these complexes, [Tb(HDAP)3⋅bathophen] exhibited excellent antimicrobial activity which proves its potential usefulness as an antimicrobial agent. Furthermore, in vitro antioxidant activity tests were carried out by using DPPH method which indicates that the complexes have considerable antioxidant activity when compared with the standard ascorbic acid. PMID:26232573

  20. Synthesis, photoluminescence and biological properties of terbium(III) complexes with hydroxyketone and nitrogen containing heterocyclic ligands

    NASA Astrophysics Data System (ADS)

    Poonam; Kumar, Rajesh; Boora, Priti; Khatkar, Anurag; Khatkar, S. P.; Taxak, V. B.

    2016-01-01

    The ternary terbium(III) complexes [Tb(HDAP)3ṡbiq], [Tb(HDAP)3ṡdmph] and [Tb(HDAP)3ṡbathophen] were prepared by using methoxy substituted hydroxyketone ligand HDAP (2-hydroxy-4,6-dimethoxyacetophenone) and an ancillary ligand 2,2-biquinoline or 5,6-dimethyl-1,10-phenanthroline or bathophenanthroline respectively. The ligand and synthesized complexes were characterised based on elemental analysis, FT-IR and 1H NMR. Thermal behaviour of the synthesized complexes illustrates the general decomposition patterns of the complexes by thermogravimetric analysis. Photophysical properties such as excitation spectra, emission spectra and luminescence decay curves of the complexes were investigated in detail. The main green emitting peak at 548 nm can be attributed to 5D4 → 7F5 of Tb3+ ion. Thus, these complexes might be used to make a bright green light-emitting diode for display purpose. In addition the in vitro antibacterial activities of HDAP and its Tb(III) complexes against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and antifungal activities against Candida albicans and Aspergillus niger are reported. The Tb3+ complexes were found to be more potent antimicrobial agent as compared to the ligand. Among all these complexes, [Tb(HDAP)3ṡbathophen] exhibited excellent antimicrobial activity which proves its potential usefulness as an antimicrobial agent. Furthermore, in vitro antioxidant activity tests were carried out by using DPPH method which indicates that the complexes have considerable antioxidant activity when compared with the standard ascorbic acid.

  1. Effects of copper amine treatments on mechanical, biological and surface/interphase properties of poly (vinyl chloride)/wood composites

    NASA Astrophysics Data System (ADS)

    Jiang, Haihong

    2005-11-01

    The copper ethanolamine (CuEA) complex was used as a wood surface modifier and a coupling agent for wood-PVC composites. Mechanical properties of composites, such as unnotched impact strength, flexural strength and flexural toughness, were significantly increased, and fungal decay weight loss was dramatically decreased by wood surface copper amine treatments. It is evident that copper amine was a very effective coupling agent and decay inhibitor for PVC/wood flour composites, especially in high wood flour loading level. A DSC study showed that the heat capacity differences (DeltaCp) of composites before and after PVC glass transition were reduced by adding wood particles. A DMA study revealed that the movements of PVC chain segments during glass transition were limited and obstructed by the presence of wood molecule chains. This restriction effect became stronger by increasing wood flour content and by using Cu-treated wood flour. Wood flour particles acted as "physical cross-linking points" inside the PVC matrix, resulting in the absence of the rubbery plateau of PVC and higher E', E'' above Tg, and smaller tan delta peaks. Enhanced mechanical performances were attributed to the improved wetting condition between PVC melts and wood surfaces, and the formation of a stronger interphase strengthened by chemical interactions between Cu-treated wood flour and the PVC matrix. Contact angles of PVC solution drops on Cu-treated wood surfaces were decreased dramatically compared to those on the untreated surfaces. Acid-base (polar), gammaAB, electron-acceptor (acid) (gamma +), electron-donor (base) (gamma-) surface energy components and the total surface energies increased after wood surface Cu-treatments, indicating a strong tendency toward acid-base or polar interactions. Improved interphase and interfacial adhesion were further confirmed by measuring interfacial shear strength between wood and the PVC matrix.

  2. Detailed characterization of mechanical properties and molecular mobility within dry seed glasses: relevance to the physiology of dry biological systems.

    PubMed

    Ballesteros, Daniel; Walters, Christina

    2011-11-01

    Slow movement of molecules in glassy matrices controls the kinetics of chemical and physical reactions in dry seeds. Variation in physiological activity among seeds suggests that there are differences in mobility among seed glasses. Testing this hypothesis is difficult because few tools are available to measure molecular mobility within dry seeds. Here, motional properties within dry pea cotyledons were assessed using dynamic mechanical analysis. The technique detected several molecular relaxations between -80 and +80°C and gave a more detailed description of water content-temperature effects on molecular motion than previously understood from studies of glass formation in seeds at glass transition (Tg). Diffusive movement is delimited by the α relaxation, which appears to be analogous to Tg. β and γ relaxations were also detected at temperatures lower than α relaxations, clearly demonstrating intramolecular motion within the glassy matrix of the pea cotyledon. Glass transitions, or the mechanical counterpart α relaxation, appear to be less relevant to seed aging during dry storage than previously thought. On the other hand, β relaxation occurs at temperature and moisture conditions typically used for seed storage and has established importance for physical aging of synthetic polymer glasses. Our data show that the nature and extent of molecular motion varies considerably with moisture and temperature, and that the hydrated conditions used for accelerated aging experiments and ultra-dry conditions sometimes recommended for seed storage give greater molecular mobility than more standard seed storage practices. We believe characterization of molecular mobility is critical for evaluating how dry seeds respond to the environment and persist through time. PMID:21831210

  3. Multimerization of cRGD peptides by click chemistry: synthetic strategies, chemical limitations, and influence on biological properties.

    PubMed

    Wängler, Carmen; Maschauer, Simone; Prante, Olaf; Schäfer, Martin; Schirrmacher, Ralf; Bartenstein, Peter; Eisenhut, Michael; Wängler, Björn

    2010-10-18

    Integrin α(ν)β(3) is overexpressed on endothelial cells of growing vessels as well as on several tumor types, and so integrin-binding radiolabeled cyclic RGD pentapeptides have attracted increasing interest for in vivo imaging of α(ν)β(3) integrin expression by positron emission tomography (PET). Of the cRGD derivatives available for imaging applications, systems comprising multiple cRGD moieties have recently been shown to exhibit highly favorable properties in relation to monomers. To assess the synthetic limits of the cRGD-multimerization approach and thus the maximum multimer size achievable by using different efficient conjugation reactions, we prepared a variety of multimers that were further investigated in vitro with regard to their avidities to integrin α(ν)β(3.) The synthesized peptide multimers containing increasing numbers of cRGD moieties on PAMAM dendrimer scaffolds were prepared by different click chemistry coupling strategies. A cRGD hexadecimer was the largest construct that could be synthesized under optimized reaction conditions, thus identifying the current synthetic limitations for cRGD multimerization. The obtained multimeric systems were conjugated to a new DOTA-based chelator developed for the derivatization of sterically demanding structures and successfully labeled with (68)Ga for a potential in vivo application. The evaluated multimers showed very high avidities-increasing with the number of cRGD moieties-in in vitro studies on immobilized α(ν)β(3) integrin and U87MG cells, of up to 131- and 124-fold, respectively, relative to the underivatized monomer. PMID:20827791

  4. Rational modification of a dendrimeric peptide with antimicrobial activity: consequences on membrane-binding and biological properties.

    PubMed

    Batoni, Giovanna; Casu, Mariano; Giuliani, Andrea; Luca, Vincenzo; Maisetta, Giuseppantonio; Mangoni, Maria Luisa; Manzo, Giorgia; Pintus, Manuela; Pirri, Giovanna; Rinaldi, Andrea C; Scorciapino, Mariano A; Serra, Ilaria; Ulrich, Anne S; Wadhwani, Parvesh

    2016-03-01

    Peptide-based antibiotics might help containing the rising tide of antimicrobial resistance. We developed SB056, a semi-synthetic peptide with a dimeric dendrimer scaffold, active against both Gram-negative and Gram-positive bacteria. Being the mechanism of SB056 attributed to disruption of bacterial membranes, we enhanced the amphiphilic profile of the original, empirically derived sequence [WKKIRVRLSA-NH2] by interchanging the first two residues [KWKIRVRLSA-NH2], and explored the effects of this modification on the interaction of peptide, both in linear and dimeric forms, with model membranes and on antimicrobial activity. Results obtained against Escherichia coli and Staphylococcus aureus planktonic strains, with or without salts at physiological concentrations, confirmed the added value of dendrimeric structure over the linear one, especially at physiological ionic strength, and the impact of the higher amphipathicity obtained through sequence modification on enhancing peptide performances. SB056 peptides also displayed intriguing antibiofilm properties. Staphylococcus epidermidis was the most susceptible strain in sessile form, notably to optimized linear analog lin-SB056-1 and the wild-type dendrimer den-SB056. Membrane affinity of all peptides increased with the percentage of negatively charged lipids and was less influenced by the presence of salt in the case of dendrimeric peptides. The analog lin-SB056-1 displayed the highest overall affinity, even for zwitterionic PC bilayers. Thus, in addition to electrostatics, distribution of charged/polar and hydrophobic residues along the sequence might have a significant role in driving peptide-lipid interaction. Supporting this view, dendrimeric analog den-SB056-1 retained greater membrane affinity in the presence of salt than den-SB056, despite the fact that they bear exactly the same net positive charge. PMID:26614437

  5. Evaluation of colloidal silica suspension as efficient additive for improving physicochemical and in vitro biological properties of calcium sulfate-based nanocomposite bone cement.

    PubMed

    Borhan, Shokoufeh; Hesaraki, Saeed; Ahmadzadeh-Asl, Shaghayegh

    2010-12-01

    In the present study new calcium sulfate-based nanocomposite bone cement with improved physicochemical and biological properties was developed. The powder component of the cement consists of 60 wt% α-calcium sulfate hemihydrate and 40 wt% biomimetically synthesized apatite, while the liquid component consists of an aqueous colloidal silica suspension (20 wt%). In this study, the above mentioned powder phase was mixed with distilled water to prepare a calcium sulfate/nanoapatite composite without any additive. Structural properties, setting time, compressive strength, in vitro bioactivity and cellular properties of the cements were investigated by appropriate techniques. From X-ray diffractometer analysis, except gypsum and apatite, no further phases were found in both silica-containing and silica-free cements. The results showed that both setting time and compressive strength of the calcium sulfate/nanoapatite cement improved by using colloidal silica suspension as cement liquid. Meanwhile, the condensed phase produced from the polymerization process of colloidal silica filled the micropores of the microstructure and covered rodlike gypsum crystals and thus controlled cement disintegration in simulated body fluid. Additionally, formation of apatite layer was favored on the surfaces of the new cement while no apatite precipitation was observed for the cement prepared by distilled water. In this study, it was also revealed that the number of viable osteosarcoma cells cultured with extracts of both cements were comparable, while silica-containing cement increased alkaline phosphatase activity of the cells. These results suggest that the developed cement may be a suitable bone filling material after well passing of the corresponding in vivo tests. PMID:20972610

  6. Metal based biologically active compounds: design, synthesis, and antibacterial/antifungal/cytotoxic properties of triazole-derived Schiff bases and their oxovanadium(IV) complexes.

    PubMed

    Chohan, Zahid H; Sumrra, Sajjad H; Youssoufi, Moulay H; Hadda, Taibi B

    2010-07-01

    A new series of oxovanadium(IV) complexes have been designed and synthesized with a new class of triazole Schiff bases derived from the reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde and acetyl pyridine-2-carboxaldehyde, respectively. Physical (magnetic susceptibility, molar conductance), spectral (IR, (1)H NMR, (13)C NMR, mass and electronic) and analytical data have established the structures of these synthesized Schiff bases and their oxovanadium(IV) complexes. The Schiff bases, predominantly act as bidentate and coordinate with the vanadium(IV) metal to give a stoichiometric ratio of 1:2 [M:L], forming a general formulae, [M(L-H)(2)] and [M(L)(2)]SO(4) where L = (L(1))-(L(4)) and M = VO(IV) of these complexes in a square-pyramidal geometry. In order to evaluate the biological activity of Schiff bases and to assess the role of vanadium(IV) metal on biological activity, the triazole Schiff bases and their oxovanadium(IV) complexes have been studied for in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, Salmonella typhi) and two Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacterial strains, in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glaberata. The simple Schiff bases showed weaker to significant activity against one or more bacterial and fungal strains. In most of the cases higher activity was exhibited upon coordination with vanadium(IV) metal. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina. PMID:20338672

  7. Effect of mineralogical, geochemical and biological properties on soils reflectance to assess temporal and spatial dynamics of BSCs in Sahelian ecosystems

    NASA Astrophysics Data System (ADS)

    Bourguignon, A.; Cerdan, O.; Desprats, J. F.; Marin, B.; Malam Issa, O.; Valentin, C.; Rajot, J. L.

    2012-04-01

    Land degradation and desertification are among the major environmental problems, resulting in reduced productivity and development of bare surfaces in arid and semi-arid areas of the world. One important factor that acts to increase soil stability and nutrient content, and thus to prevent water and wind erosion and enhance soil productivity of arid environment, is the presence of biological soil crusts (BSCs). They are the dominant ground cover and a key component of arid environments built up mainly by cyanobacteria. They enhance degraded soil quality by providing a stable and water-retaining substratum and increasing fertility by N and C fixations. The BioCrust project, funded by ANR (VMCS 2008), focuses on BSCs in the Sahelian zone of West Africa (Niger), a highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use. Unlike arid areas of developed countries (USA, Australia and Israel) or China where BSCs have been extensively studied, studies from Sahelian zone (Africa) are limited (neither the inventory of their different form nor the estimation of their spatial extension has been carried out). The form, structure and composition of BSCs vary depending on characteristics related to soils and biological composition. This study focuses on the soils characterisation using ground-based spectroradiometry. An extensive database was built included spectral measurements on BSCs, bare soils and vegetation that occur in the same area, visual criteria, in situ and laboratory measurements on the physical, chemical and biological characteristics of BSCs and their substratum. The work is carried out on geo-statistical processing of data acquired in sites along a north-south climatic gradient and three types of representative land uses. The investigated areas are highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic

  8. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Reflecting widespread unhappiness with the growing tax burdens in this country, the most active area of litigation reported in the property chapter this year involves various attempts by taxpayers to prevent the construction or remodeling of public school facilities. While some taxpayers fought to keep schools from being built, others in New York…

  9. Biological Technicians

    MedlinePlus

    ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ...

  10. Biological and bactericidal properties of Ag-doped bioactive glass in a natural extracellular matrix hydrogel with potential application in dentistry.

    PubMed

    Wang, Y-Y; Chatzistavrou, X; Faulk, D; Badylak, S; Zheng, L; Papagerakis, S; Ge, L; Liu, H; Papagerakis, P

    2015-01-01

    The aim of this study was the fabrication and evaluation of a novel bioactive and bactericidal material, which could have applications in dentistry by supporting tissue regeneration and killing oral bacteria. Our hypothesis was that a new scaffold for pulp-dentin tissue engineering with enhanced antibacterial activity could be obtained by associating extracellular matrix derived from porcine bladder with an antibacterial bioactive glass. Our study combines in vitro approaches and ectopic implantation in scid mice. The novel material was fabricated by incorporating a sol-gel derived silver (Ag)-doped bioactive glass (BG) in a natural extracellular matrix (ECM) hydrogel in ratio 1:1 in weight % (Ag-BG/ECM). The biological properties of the Ag-BG/ECM were evaluated in culture with dental pulp stem cells (DPSCs). In particular, cell proliferation, cell apoptosis, stem cells markers profile, and cell differentiation potential were studied. Furthermore, the antibacterial activity against Streptococcus mutans and Lactobacillus casei was measured. Moreover, the capability of the material to enhance pulp/dentin regeneration in vivo was also evaluated. Our data show that Ag-BG/ECM significantly enhances DPSCs' proliferation, it does not affect cell morphology and stem cells markers profile, protects cells from apoptosis, and enhances in vitro cell differentiation and mineralisation potential as well as in vivo dentin formation. Furthermore, Ag-BG/ECM strongly inhibits S. mutans and L. casei growth suggesting that the new material has also anti-bacterial properties. This study provides foundation for future clinical applications in dentistry. It could potentially advance the currently available options of dental regenerative materials. PMID:26091732

  11. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)-bioglass/chitosan-collagen composite scaffolds: a bone tissue engineering applications.

    PubMed

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze-thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. PMID:24656353

  12. Effects of SiO2 and ZnO doping on mechanical and biological properties of 3D printed TCP scaffolds

    PubMed Central

    Fielding, Gary A.; Bandyopadhyay, Amit; Bose, Susmita

    2011-01-01

    Objectives To evaluate the effects of SiO2 (0.5 wt %) and ZnO (0.25 wt %) dopants on the mechanical and biological properties of tricalcium phosphate (TCP) scaffolds with three dimensionally (3D) interconnected pores. Methods Scaffolds were created with a commercial 3D printer. Post sintering phase analysis was determined by x-ray diffraction. Surface morphology of the scaffolds was examined by field emission electron microscopy. Mechanical strength was evaluated with a screw driven universal testing machine. MTT assay was used for cellular proliferation characteristics and cellular morphology was examined by field emission electron microscopy. Results Addition of dopants into TCP increased the average density of pure TCP from 90.8 ± 0.8% to 94.1 ± 1.6% and retarded the β to α phase transformation at high sintering temperatures, which resulted in up to 2.5 fold increase in compressive strength. In vitro cell-materials interaction studies, carried out using hFOB cells, confirmed that the addition of SiO2 and ZnO to the scaffolds facilitates faster cell proliferation when compared to pure TCP scaffolds. Significance Addition of SiO2 and ZnO dopants to the TCP scaffolds showed increased mechanical strength as well as increased cellular proliferation. PMID:22047943

  13. Adult Stem Cells Properties in Terms of Commitment, Aging and Biological Safety of Grit-Blasted and Acid-Etched Ti Dental Implants Surfaces

    PubMed Central

    Gardin, Chiara; Ferroni, Letizia; Bressan, Eriberto; Calvo - Guirado, José L.; Degidi, Marco; Piattelli, Adriano; Zavan, Barbara

    2014-01-01

    Titanium (Ti) is one of the most widely used biomaterials for manufacturing dental implants. The implant surface properties strongly influence osseointegration. The aim of the present study was to in vitro investigate the characteristics of Ti dental implants in terms of mutagenicity, hemocompatibility, biocompatibility, osteoinductivity and biological safety. The Ames test was used to test the mutagenicity of the Ti dental implants, and the hemolysis assay for evaluating their hemocompatibility. Human adipose - derived stem cells (ADSCs) were then seeded onto these implants in order to evaluate their cytotoxicity. Gene expression analyzing with real-time PCR was carried out to investigate the osteoinductivity of the biomaterials. Finally, the genetic stability of the cells cultured onto dental implants was determined by karyotyping. Our results demonstrated that Ti dental implants are not mutagenic, do not cause hemolysis, and are biocompatible. The MTT assay revealed that ADSCs, seeded on Ti dental implants, proliferate up to 30 days in culture. Moreover, ADSCs loaded on Ti dental implants show a substantial expression of some osteoblast specific markers, such as COL1A1, OPN, ALPL, and RUNX2, as well as chromosomal stability after 30 days of culture in a medium without osteogenic factors. In conclusion, the grit-blasted and acid-etched treatment seems to favor the adhesion and proliferation of ADSCs and improve the osteoinductivity of Ti dental implant surfaces. PMID:25635249

  14. Impact of enzyme- and ultrasound-assisted extraction methods on biological properties of red, brown, and green seaweeds from the central west coast of Portugal.

    PubMed

    Rodrigues, Dina; Sousa, Sérgio; Silva, Aline; Amorim, Manuela; Pereira, Leonel; Rocha-Santos, Teresa A P; Gomes, Ana M P; Duarte, Armando C; Freitas, Ana Cristina

    2015-04-01

    Seaweeds are an excellent source of bioactive compounds, and therefore the use of sustainable and food compatible extraction methods such as enzyme-assisted (EAE) and ultrasound-assisted extraction were applied on Sargassum muticum, Osmundea pinnatifida, and Codium tomentosum. Extracts were evaluated for proximate characterization and biological properties. Higher extraction yields were observed for C. tomentosum EAE (48-62%; p < 0.05 for Cellulase and Viscozyme), followed by O. pinnatifida (49-55%; p < 0.05 except Alcalase) and S. muticum (26-31%; p < 0.05). S. muticum extracts presented the highest nitrogen (25 ± 2 mg/glyoph extract) and total phenolics (261 ± 37 μgcatechol equiv/glyoph extract) contents, whereas higher sugars (78 ± 14 mgglucose equiv/glyoph extract) including sulfated polysaccharide (44 ± 8 mgNa2SO4 acid/glyoph extract) contents characterized O. pinnatifida extracts. A higher effect on hydroxyl-radical scavenging activity (35-50%) was observed for all extracts, whereas S. muticum Alcalase and C. tomentosum Cellulase extracts exhibited higher prebiotic activity than fructooligosaccharides. O. pinnatifida and C. tomentosum EAE showed inhibitory potential against α-glucosidase (38-49%). PMID:25756735

  15. The MUC1 oncomucin regulates pancreatic cancer cell biological properties and chemoresistance. Implication of p42–44 MAPK, Akt, Bcl-2 and MMP13 pathways

    SciTech Connect

    Tréhoux, Solange; Duchêne, Bélinda; Jonckheere, Nicolas; Van Seuningen, Isabelle

    2015-01-16

    Highlights: • Loss of MUC1 decreases proliferation and tumor growth via β-catenin and p42–44 MAPK. • Inhibition of MUC1 decreases cell migration and invasion through MMP13. • Loss of MUC1 decreases survival and increases apoptosis via Akt and Bcl-2 pathways. • Loss of MUC1 sensitizes cells to gemcitabine and 5-Fluorouracil chemotherapeutic drugs. - Abstract: MUC1 is an oncogenic mucin overexpressed in several epithelial cancers, including pancreatic ductal adenocarcinoma, and is considered as a potent target for cancer therapy. To this aim, we undertook to study MUC1 biological effects on pancreatic cancer cells and identify pathways mediating these effects. Our in vitro experiments indicate that inhibiting MUC1 expression decreases cell proliferation, cell migration and invasion, cell survival and increases cell apoptosis. Moreover, lack of MUC1 in these cells profoundly altered their sensitivity to gemcitabine and 5-Fluorouracil chemotherapeutic drugs. In vivo MUC1-KD cell xenografts in SCID mice grew slower. Altogether, we show that MUC1 oncogenic mucin alters proliferation, migration, and invasion properties of pancreatic cancer cells and that these effects are mediated by p42–44 MAPK, Akt, Bcl-2 and MMP13 pathways.

  16. ABCG2-overexpressing S1-M1-80 cell xenografts in nude mice keep original biochemistry and cell biological properties

    PubMed Central

    Wang, Fang; Liang, Yong-Ju; Wu, Xing-Ping; Su, Xiao-Dong; Fu, Li-Wu

    2012-01-01

    S1-M1-80 cells, derived from human colon carcinoma S1 cells, are mitoxantrone-selected ABCG2-overexpressing cells and are widely used in in vitro studies of multidrug resistance (MDR). In this study, S1-M1-80 cell xenografts were established to investigate whether the MDR phenotype and cell biological properties were maintained in vivo. Our results showed that the proliferation, cell cycle, and ABCG2 expression level in S1-M1-80 cells were similar to those in cells isolated from S1-M1-80 cell xenografts (named xS1-M1-80 cells). Consistently, xS1-M1-80 cells exhibited high levels of resistance to ABCG2 substrates such as mitoxantrone and topotecan, but remained sensitive to the non-ABCG2 substrate cisplatin. Furthermore, the specific ABCG2 inhibitor Ko143 potently sensitized xS1-M1-80 cells to mitoxantrone and topotecan. These results suggest that S1-M1-80 cell xenografts in nude mice retain their original cytological characteristics at 9 weeks. Thus, this model could serve as a good system for further investigation of ABCG2-mediated MDR. PMID:22360854

  17. Biological materials: (Part A): Temperature-responsive polymers and drug delivery, and, (Part B): Polymer modification of fish scale and their nano-mechanical properties

    NASA Astrophysics Data System (ADS)

    Xiang, Xu

    This research has three parts. Two parts deal with novel nanoparticle assemblies for drug delivery, and are described in Part A, while the third part looks at properties of fish scales, an abundant and little-used waste resource, that can be modified to have value in medical and other areas. Part A describes fundamental research into the affects of block sequence of amphiphilic block copolymers prepared from on a new and versatile class of monomers, oligo(ethylene glycol) methyl ether acrylate (OEGA) and the more hydrophobic di(ethylene glycol) methyl ether methacrylate (DEGMA). Polymers from these monomers are biologically safe and give polymers with thermoresponsive properties that can be manipulated over a broader temperature range than the more researched N-isopropylacrylamide polymers. Using RAFT polymerization and different Chain Transfer Agents (CTAs) amphiphilic block copolymers were prepared to study the effect of block sequence (hydrophilic OEGA and more hydrophobic DEGMA) on their thermo-responsive properties. Pairing hydrophilic chain ends to a hydrophobic DEGMA block and hydrophobic chain ends to hydrophilic blocks ("mis-matched polarity") significantly affected thermoresponsive properties for linear and star diblock copolymers, but little affected symmetric triblock copolymers. Specifically matching polarity in diblock copolymers yielded nanoparticles with higher cloud points (CP), narrow temperature ranges for coil collapse above CP, and smaller hydrodynamic diameter than mis-matched polarity. Using this knowledge two linear OEGA/DEGMA diblock copolymers were prepared with thiol end groups and assembled into hybrid nanoparticles with a gold nanoparticle core (GNP-polymer hybrids). This design was made using the hypothesis that a hybrid polymer drug carrier with a high CP (50-60 °C) and a diblock structure could be designed with low levels of drug release below 37 °C (body temperature) allowing the drug carrier to reach a target (tumor) site with

  18. Biological Filters.

    ERIC Educational Resources Information Center

    Klemetson, S. L.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. The review is concerned with biological filters, and it covers: (1) trickling filters; (2) rotating biological contractors; and (3) miscellaneous reactors. A list of 14 references is also presented. (HM)

  19. Biological Agents

    MedlinePlus

    ... to Z Index Contact Us FAQs What's New Biological Agents This page requires that javascript be enabled ... and Health Topics A-Z Index What's New Biological agents include bacteria, viruses, fungi, other microorganisms and ...

  20. Biological aerosol background characterization

    NASA Astrophysics Data System (ADS)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  1. An Investigation into the Effects of Interface Stress and Interfacial Arrangement on Temperature Dependent Thermal Properties of a Biological and a Biomimetic Material

    SciTech Connect

    Tomar, Vikas

    2015-01-13

    A significant effort in the biomimetic materials research is on developing materials that can mimic and function in the same way as biological tissues, on bio-inspired electronic circuits, on bio-inspired flight structures, on bio-mimetic materials processing, and on structural biomimetic materials, etc. Most structural biological and biomimetic material properties are affected by two primary factors: (1) interfacial interactions between an organic and an inorganic phase usually in the form of interactions between an inorganic mineral phase and organic protein network; and (2) structural arrangement of the constituents. Examples are exoskeleton structures such as spicule, nacre, and crustacean exoskeletons. A significant effort is being directed towards making synthetic biomimetic materials based on a manipulation of the above two primary factors. The proposed research is based on a hypothesis that in synthetic materials with biomimetic morphology thermal conductivity, k, (how fast heat is carried away) and thermal diffusivity, D, (how fast a material’s te