WorldWideScience

Sample records for non-replicative biological role

  1. On the biological role of gravity.

    Science.gov (United States)

    Gazenko, O G; Gurjian, A A

    1965-01-01

    The paper is dedicated to the memory of Galileo Galilei whose work is a great contribution to the development of a new branch of science--gravitation biology. Penetration of man into outer space necessitates a study of the role of gravity in the onto- and phylogenetic development of living organisms. This allows one to get insight into the biological action of weightlessness under the conditions of long-term space flight. The paper summarizes some results of the investigation of weightlessness effects in experiments on animals and during flights of Soviet and American astronauts. The rearing of animals in a special centrifuge under the conditions of prolonged action of accelerations simulating an increased gravity affects noticeably the formation of vegetative (height, weight, metabolism) and animal (vestibulo-tonic reflexes) functions as well as reactivity of the organism. Experiments employing the rearing of animals in a centrifuge represent one of the most promising methods of studying the urgent problem--biological action of increased and decreased gravitation conditions.

  2. Thioredoxin in vascular biology: role in hypertension.

    Science.gov (United States)

    Ebrahimian, Talin; Touyz, Rhian M

    2008-06-01

    The thioredoxin (TRX) system consists of TRX, TRX reductase, and NAD(P)H, and is able to reduce reactive oxygen species (ROS) through interactions with the redox-active center of TRX, which in turn can be reduced by TRX reductase in the presence of NAD(P)H. Among the TRX superfamily is peroxiredoxin (PRX), a family of non-heme peroxidases that catalyzes the reduction of hydroperoxides into water and alcohol. The TRX system is active in the vessel wall and functions either as an important endogenous antioxidant or interacts directly with signaling molecules to influence cell growth, apoptosis, and inflammation. Recent evidence implicates TRX in cardiovascular disease associated with oxidative stress, such as cardiac failure, arrhythmia, ischemia reperfusion injury, and hypertension. Thioredoxin activity is influenced by many mechanisms, including transcription, protein-protein interaction, and post-translational modification. Regulation of TRX in hypertensive models seems to be related to oxidative stress and is tissue- and cell-specific. Depending on the models of hypertension, TRX system could be upregulated or downregulated. The present review focuses on the role of TRX in vascular biology, describing its redox activities and biological properties in the media and endothelium of the vessel wall. In addition, the pathopysiological role of TRX in hypertension and other cardiovascular diseases is addressed.

  3. Hydrogen sulfide: metabolism, biological and medical role

    Directory of Open Access Journals (Sweden)

    N. V. Zaichko

    2014-10-01

    Full Text Available Hydrogen sulfide (H2S is a signaling molecule that is actively synthesized in the tissues and is involved in the regulation of vascular tone, neuromodulation, cytoprotection, inflammation and apoptosis. In recent years, new data on animal and human H2S metabolism and function under the effect of various endogenous and exogenous factors, including drugs were collected. This review is provided to introduce generalized information about the main and alternative H2S metabolism and regulation, peculiarities of transport, signaling, biological role and participation in pathogenesis. Submitted data describe H2S content and activity of H2S-synthesizing enzymes in different organs, H2S effect on blood coagulation and platelet aggregation based on our research results. The working classification of H2S metabolism modulators, which are used in biology and medicine, is proposed: 1 agents that increase H2S content in tissues (inorganic and organic H2S donors; H2S-synthesizing enzymes substrates and their derivatives, H2S-releasing drugs; agents that contain H2S-synthesizing enzymes cofactors and activators, agents that inhibit H2S utilization; 2 agents that reduce H2S content in tissues (specific and nonspecific inhibitors of H2S-synthesizing enzymes, 3 agents with uncertain impact on H2S metabolism (some medicines. It was demonstrated that vitamin-microelement and microelement complexes with H2S-synthesizing enzymes cofactors and activators represent a promising approach for H2S content correction in tissues.

  4. Bringing RNA into View: RNA and Its Roles in Biology.

    Science.gov (United States)

    Atkins, John F.; Ellington, Andrew; Friedman, B. Ellen; Gesteland, Raymond F.; Noller, Harry F.; Pasquale, Stephen M.; Storey, Richard D.; Uhlenbeck, Olke C.; Weiner, Alan M.

    This guide presents a module for college students on ribonucleic acid (RNA) and its role in biology. The module aims to integrate the latest research and its findings into college-level biology and provide an opportunity for students to understand biological processes. Four activities are presented: (1) "RNA Structure: Tapes to Shapes"; (2) "RNA…

  5. Role of biologics in intractable urticaria

    Directory of Open Access Journals (Sweden)

    Cooke A

    2015-04-01

    Full Text Available Andrew Cooke,1 Adeeb Bulkhi,1,2 Thomas B Casale1 1Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida, Tampa, FL, USA; 2Department of Internal Medicine, College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia Abstract: Chronic urticaria (CU is a common condition faced by many clinicians. CU has been estimated to affect approximately 0.5%–1% of the population, with nearly 20% of sufferers remaining symptomatic 20 years after onset. Antihistamines are the first-line therapy for CU. Unfortunately, nearly half of these patients will fail this first-line therapy and require other medication, including immune response modifiers or biologics. Recent advances in our understanding of urticarial disorders have led to more targeted therapeutic options for CU and other urticarial diseases. The specific biologic agents most investigated for antihistamine-refractory CU are omalizumab, rituximab, and intravenous immunoglobulin (IVIG. Of these, the anti-IgE monoclonal antibody omalizumab is the best studied, and has recently been approved for the management of CU. Other agents, such as interleukin-1 inhibitors, have proved beneficial for Schnitzler syndrome and cryopyrin-associated periodic syndromes (CAPS, diseases associated with urticaria. This review summarizes the relevant data regarding the efficacy of biologics in antihistamine-refractory CU. Keywords: chronic urticaria, omalizumab, intravenous immunoglobulin, anakinra, canakinumab

  6. Genetically Thermo-Stabilised, Immunogenic Poliovirus Empty Capsids; a Strategy for Non-replicating Vaccines

    Science.gov (United States)

    Fox, Helen; Minor, Philip D.

    2017-01-01

    While wild type polio has been nearly eradicated there will be a need to continue immunisation programmes for some time because of the possibility of re-emergence and the existence of long term excreters of poliovirus. All vaccines in current use depend on growth of virus and most of the non-replicating (inactivated) vaccines involve wild type viruses known to cause poliomyelitis. The attenuated vaccine strains involved in the eradication programme have been used to develop new inactivated vaccines as production is thought safer. However it is known that the Sabin vaccine strains are genetically unstable and can revert to a virulent transmissible form. A possible solution to the need for virus growth would be to generate empty viral capsids by recombinant technology, but hitherto such particles are so unstable as to be unusable. We report here the genetic manipulation of the virus to generate stable empty capsids for all three serotypes. The particles are shown to be extremely stable and to generate high levels of protective antibodies in animal models. PMID:28103317

  7. Biological role of lectins: A review

    Directory of Open Access Journals (Sweden)

    K Kiran Kumar

    2012-01-01

    Full Text Available Lectins comprise a stracturally vary diverse class of proteins charecterized by their ability to selectively bind carbohydrate moieties of the glycoproteins of the cell surface. Lectins may be derived from plants, microbial or animal sources and may be soluble or membrane bound. Lectins is a tetramer made up of four nearly identical subunits. In human, lectins have been reported to cause food poisoning, hemolytic anemia, jaundice, digestive distress, protein and carbohydrate malabsorption and type I allergies. The present review focuses on the classification, structures, biological significance and application of lectins.

  8. Quantitative cell biology: the essential role of theory.

    Science.gov (United States)

    Howard, Jonathon

    2014-11-05

    Quantitative biology is a hot area, as evidenced by the recent establishment of institutes, graduate programs, and conferences with that name. But what is quantitative biology? What should it be? And how can it contribute to solving the big questions in biology? The past decade has seen very rapid development of quantitative experimental techniques, especially at the single-molecule and single-cell levels. In this essay, I argue that quantitative biology is much more than just the quantitation of these experimental results. Instead, it should be the application of the scientific method by which measurement is directed toward testing theories. In this view, quantitative biology is the recognition that theory and models play critical roles in biology, as they do in physics and engineering. By tying together experiment and theory, quantitative biology promises a deeper understanding of underlying mechanisms, when the theory works, or to new discoveries, when it does not.

  9. Oral keratinocytes support non-replicative infection and transfer of harbored HIV-1 to permissive cells

    Directory of Open Access Journals (Sweden)

    Giacaman Rodrigo A

    2008-07-01

    Full Text Available Abstract Background Oral keratinocytes on the mucosal surface are frequently exposed to HIV-1 through contact with infected sexual partners or nursing mothers. To determine the plausibility that oral keratinocytes are primary targets of HIV-1, we tested the hypothesis that HIV-1 infects oral keratinocytes in a restricted manner. Results To study the fate of HIV-1, immortalized oral keratinocytes (OKF6/TERT-2; TERT-2 cells were characterized for the fate of HIV-specific RNA and DNA. At 6 h post inoculation with X4 or R5-tropic HIV-1, HIV-1gag RNA was detected maximally within TERT-2 cells. Reverse transcriptase activity in TERT-2 cells was confirmed by VSV-G-mediated infection with HIV-NL4-3Δenv-EGFP. AZT inhibited EGFP expression in a dose-dependent manner, suggesting that viral replication can be supported if receptors are bypassed. Within 3 h post inoculation, integrated HIV-1 DNA was detected in TERT-2 cell nuclei and persisted after subculture. Multiply spliced and unspliced HIV-1 mRNAs were not detectable up to 72 h post inoculation, suggesting that HIV replication may abort and that infection is non-productive. Within 48 h post inoculation, however, virus harbored by CD4 negative TERT-2 cells trans infected co-cultured peripheral blood mononuclear cells (PBMCs or MOLT4 cells (CD4+ CCR5+ by direct cell-to-cell transfer or by releasing low levels of infectious virions. Primary tonsil epithelial cells also trans infected HIV-1 to permissive cells in a donor-specific manner. Conclusion Oral keratinocytes appear, therefore, to support stable non-replicative integration, while harboring and transmitting infectious X4- or R5-tropic HIV-1 to permissive cells for up to 48 h.

  10. Characterization and biological role of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Aneta Wójtowicz

    2014-12-01

    Full Text Available Extracellular vesicles (EV form a heterogeneous population of mostly spherical membrane structures released by almost all cells, including tumour cells, both in vivo and in vitro. Their size varies from 30 nm to 1 μm, and size is one of the main criteria of the selection of two categories of EV: small (30-100 nm, more homogeneous exosomes and larger fragments (0.1-1 μm called membrane microvesicles or ectosomes. The presence of EV has already been detected in many human body fluids: blood, urine, saliva, semen and amniotic fluid. Formation of EV is tightly controlled, and their function and biochemical composition depend on the cell type they originate from. EV are the “vehicles” of bioactive molecules, such as proteins, mRNA and microRNA, and may play an important role in intercellular communication and modulation of e.g. immune system cell activity. In addition, on the surface of tumour-derived microvesicles (TMV, called oncosomes, several markers specific for cancer cells were identified, which indicates a role of TMV in tumour growth and cancer development. On the other hand, TMV may be an important source of tumour-associated antigens (TAA which can be potentially useful as biomarkers with prognostic value, as well as in development of new forms of targeted immunotherapy of cancer.

  11. Rapid transient production in plants by replicating and non-replicating vectors yields high quality functional anti-HIV antibody.

    Directory of Open Access Journals (Sweden)

    Frank Sainsbury

    Full Text Available The capacity of plants and plant cells to produce large amounts of recombinant protein has been well established. Due to advantages in terms of speed and yield, attention has recently turned towards the use of transient expression systems, including viral vectors, to produce proteins of pharmaceutical interest in plants. However, the effects of such high level expression from viral vectors and concomitant effects on host cells may affect the quality of the recombinant product.To assess the quality of antibodies transiently expressed to high levels in plants, we have expressed and characterised the human anti-HIV monoclonal antibody, 2G12, using both replicating and non-replicating systems based on deleted versions of Cowpea mosaic virus (CPMV RNA-2. The highest yield (approximately 100 mg/kg wet weight leaf tissue of affinity purified 2G12 was obtained when the non-replicating CPMV-HT system was used and the antibody was retained in the endoplasmic reticulum (ER. Glycan analysis by mass-spectrometry showed that the glycosylation pattern was determined exclusively by whether the antibody was retained in the ER and did not depend on whether a replicating or non-replicating system was used. Characterisation of the binding and neutralisation properties of all the purified 2G12 variants from plants showed that these were generally similar to those of the Chinese hamster ovary (CHO cell-produced 2G12.Overall, the results demonstrate that replicating and non-replicating CPMV-based vectors are able to direct the production of a recombinant IgG similar in activity to the CHO-produced control. Thus, a complex recombinant protein was produced with no apparent effect on its biochemical properties using either high-level expression or viral replication. The speed with which a recombinant pharmaceutical with excellent biochemical characteristics can be produced transiently in plants makes CPMV-based expression vectors an attractive option for

  12. Researchers Reveal Ecological Roles of Biological Soil Crusts in Desert

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Biological soil crust is a complex organic integrity of cyanobacteria, green algae, lichens and mosses, fungi, and other bacteria. This is a common and widespread phenomenon in desert areas all over the world. Biologically,this kind of soil crust differs a lot from physical ones in terms of physical and chemical properties, and become important biological factors in vegetation succession. Despite its unassuming appearance, the crust plays a significant role in the desert ecosystem, involving the process of soil formation, stability and fertility,the prevention of soil erosion by water or wind, the increased possibility of vascular plants colonization, and the stabilization of sand dunes.

  13. The role of epigenetics in the biology of multiple myeloma

    DEFF Research Database (Denmark)

    Dimopoulos, K; Gimsing, P; Grønbæk, K

    2014-01-01

    Several recent studies have highlighted the biological complexity of multiple myeloma (MM) that arises as a result of several disrupted cancer pathways. Apart from the central role of genetic abnormalities, epigenetic aberrations have also been shown to be important players in the development of MM...

  14. Brain disorders and the biological role of music.

    Science.gov (United States)

    Clark, Camilla N; Downey, Laura E; Warren, Jason D

    2015-03-01

    Despite its evident universality and high social value, the ultimate biological role of music and its connection to brain disorders remain poorly understood. Recent findings from basic neuroscience have shed fresh light on these old problems. New insights provided by clinical neuroscience concerning the effects of brain disorders promise to be particularly valuable in uncovering the underlying cognitive and neural architecture of music and for assessing candidate accounts of the biological role of music. Here we advance a new model of the biological role of music in human evolution and the link to brain disorders, drawing on diverse lines of evidence derived from comparative ethology, cognitive neuropsychology and neuroimaging studies in the normal and the disordered brain. We propose that music evolved from the call signals of our hominid ancestors as a means mentally to rehearse and predict potentially costly, affectively laden social routines in surrogate, coded, low-cost form: essentially, a mechanism for transforming emotional mental states efficiently and adaptively into social signals. This biological role of music has its legacy today in the disordered processing of music and mental states that characterizes certain developmental and acquired clinical syndromes of brain network disintegration. © The Author (2014). Published by Oxford University Press.

  15. Evolution and Biological Roles of Alternative 3'UTRs.

    Science.gov (United States)

    Mayr, Christine

    2016-03-01

    More than half of human genes use alternative cleavage and polyadenylation to generate alternative 3' untranslated region (3'UTR) isoforms. Most efforts have focused on transcriptome-wide mapping of alternative 3'UTRs and on the question of how 3'UTR isoform ratios may be regulated. However, it remains less clear why alternative 3'UTRs have evolved and what biological roles they play. This review summarizes our current knowledge of the functional roles of alternative 3'UTRs, including mRNA localization, mRNA stability, and translational efficiency. Recent work suggests that alternative 3'UTRs may also enable the formation of protein-protein interactions to regulate protein localization or to diversify protein functions. These recent findings open an exciting research direction for the investigation of new biological roles of alternative 3'UTRs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Role of inositol phospholipid signaling in natural killer cell biology

    Directory of Open Access Journals (Sweden)

    Matthew eGumbleton

    2013-03-01

    Full Text Available Natural Killer (NK cells are important in the host defense against malignancy and infection. At a cellular level NK cells are activated when signals from activating receptors exceed signaling from inhibitory receptors. At a molecular level NK cells undergo an education process to prevent autoimmunity. Mouse models have shown important roles for inositol phospholipid signaling in lymphocytes. NK cells from mice with deletion in different members of the PI3K signaling pathway have defective development, natural killer cell repertoire expression (NKRR and effector function. Here we review the role of inositol phospholipid signaling in NK cell biology.

  17. Menaquinone synthesis is critical for maintaining mycobacterial viability during exponential growth and recovery from non-replicating persistence.

    Science.gov (United States)

    Dhiman, Rakesh K; Mahapatra, Sebabrata; Slayden, Richard A; Boyne, Melissa E; Lenaerts, Anne; Hinshaw, Jerald C; Angala, Shiva K; Chatterjee, Delphi; Biswas, Kallolmay; Narayanasamy, Prabagaran; Kurosu, Michio; Crick, Dean C

    2009-04-01

    Understanding the basis of bacterial persistence in latent infections is critical for eradication of tuberculosis. Analysis of Mycobacterium tuberculosis mRNA expression in an in vitro model of non-replicating persistence indicated that the bacilli require electron transport chain components and ATP synthesis for survival. Additionally, low microM concentrations of aminoalkoxydiphenylmethane derivatives inhibited both the aerobic growth and survival of non-replicating, persistent M. tuberculosis. Metabolic labelling studies and quantification of cellular menaquinone levels suggested that menaquinone synthesis, and consequently electron transport, is the target of the aminoalkoxydiphenylmethane derivatives. This hypothesis is strongly supported by the observations that treatment with these compounds inhibits oxygen consumption and that supplementation of growth medium with exogenous menaquinone rescued both growth and oxygen consumption of treated bacilli. In vitro assays indicate that the aminoalkoxydiphenylmethane derivatives specifically inhibit MenA, an enzyme involved in the synthesis of menaquinone. Thus, the results provide insight into the physiology of mycobacterial persistence and a basis for the development of novel drugs that enhance eradication of persistent bacilli and latent tuberculosis.

  18. Prokaryotic membrane vesicles: new insights on biogenesis and biological roles.

    Science.gov (United States)

    Haurat, M Florencia; Elhenawy, Wael; Feldman, Mario F

    2015-02-01

    Biogenesis and trafficking of membrane vesicles are essential and well-studied processes in eukaryotes. In contrast, vesiculation in bacteria is not well understood. Outer membrane vesicles (OMVs) are produced in Gram-negative bacteria by blebbing of the outer membrane. In addition to the roles in pathogenesis, cell-to-cell communication and stress response, recent work has suggested that OMVs play important roles in immunomodulation and the establishment and balance of the gut microbiota. In this review we discuss the known and novel roles of OMVs and the different biogenesis models proposed, and address the evidence for cargo selection into OMVs. We also discuss the growing evidence for the existence of membrane vesicles in Gram-positive bacteria and Archaea. Due to their biological importance and promising applications in vaccinology, the biogenesis of OMVs is an important topic in microbiology.

  19. The emerging role of triple helices in RNA biology.

    Science.gov (United States)

    Conrad, Nicholas K

    2014-01-01

    The ability of RNA to form sophisticated secondary and tertiary structures enables it to perform a wide variety of cellular functions. One tertiary structure, the RNA triple helix, was first observed in vitro over 50 years ago, but biological activities for triple helices are only beginning to be appreciated. The recent determination of several RNA structures has implicated triple helices in distinct biological functions. For example, the SAM-II riboswitch forms a triple helix that creates a highly specific binding pocket for S-adenosylmethionine. In addition, a triple helix in the conserved pseudoknot domain of the telomerase-associated RNA TER is essential for telomerase activity. A viral RNA cis-acting RNA element called the ENE contributes to the nuclear stability of a viral noncoding RNA by forming a triple helix with the poly(A) tail. Finally, a cellular noncoding RNA, MALAT1, includes a triple helix at its 3'-end that contributes to RNA stability, but surprisingly also supports translation. These examples highlight the diverse roles that RNA triple helices play in biology. Moreover, the dissection of triple helix mechanisms has the potential to uncover fundamental pathways in cell biology.

  20. [Biological roles of complement and recent topics in clinical medicine].

    Science.gov (United States)

    Wakamiya, Nobutaka

    2012-08-01

    The complement has been identified as a complementation factor to compensate for the function of an antibody. The complement consists of C1-C9, a complement-related molecule, and its regulating molecules. Three major biological roles of the complement have been classified: First: opsonization following phagocytosis and the elimination of microbes; second: direct destruction of bacteria due to membrane attack complex (MAC); third: complement activation following the induction of anaphylactoid factors and local recruitment and activation of neutrophilic leukocytes. In this review, the basic findings and recent treatments of paroxysmal nocturnal hemoglobinuria (PNH) and hereditary angioedema (HAE) are summarized. Finally, there is a short review of a rare autosomal recessive disorder of 3MC syndrome and new biological functions of complement factors except for that of innate immunity are proposed.

  1. Tandem Repeats in Proteins : Prediction Algorithms and Biological Role

    Directory of Open Access Journals (Sweden)

    Marco ePellegrini

    2015-09-01

    Full Text Available Tandem repetitions in protein sequence and structure is a fascinatingsubject of research which has been a focus of study since the late 1990's.In this survey we give an overviewon the multi-faceted aspects of research on protein tandem repeats textcolor{red}{(PTR for short}, including prediction algorithms, databases,early classification efforts, mechanisms of PTR formation and evolution, and synthetic PTR design.We also touch on the rather open issue of the relationship between PTRand flexibility (or disorder in proteins.Detection of PTR either from protein sequence or structure data is challenging due to inherent high (biological signal-to-noise ratio that is a key feature of this problem.As early in silico analytic tools have been key enablers for starting this field of study, we expect that current and future algorithmic and statistical breakthroughs willhave a high impact on the investigations of the biological role of PTR.

  2. Role of extracellular exopolymers on biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-nan; XUE Gang; YU Shui-li; ZHAO Fang-bo

    2006-01-01

    Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

  3. Context Dependence of Students' Views about the Role of Equations in Understanding Biology

    Science.gov (United States)

    Watkins, Jessica; Elby, Andrew

    2013-01-01

    Students' epistemological views about biology--their ideas about what "counts" as learning and understanding biology--play a role in how they approach their courses and respond to reforms. As introductory biology courses incorporate more physics and quantitative reasoning, student attitudes about the role of equations in biology become…

  4. Context Dependence of Students' Views about the Role of Equations in Understanding Biology

    Science.gov (United States)

    Watkins, Jessica; Elby, Andrew

    2013-01-01

    Students' epistemological views about biology--their ideas about what "counts" as learning and understanding biology--play a role in how they approach their courses and respond to reforms. As introductory biology courses incorporate more physics and quantitative reasoning, student attitudes about the role of equations in biology become…

  5. Context Dependence of Students' Views about the Role of Equations in Understanding Biology

    Science.gov (United States)

    Watkins, Jessica; Elby, Andrew

    2013-01-01

    Students' epistemological views about biology--their ideas about what "counts" as learning and understanding biology--play a role in how they approach their courses and respond to reforms. As introductory biology courses incorporate more physics and quantitative reasoning, student attitudes about the role of equations in biology become especially…

  6. STAT6: its role in interleukin 4-mediated biological functions.

    Science.gov (United States)

    Takeda, K; Kishimoto, T; Akira, S

    1997-05-01

    Interleukin (IL) 4 is known to be a cytokine which plays a central role in the regulation of immune response. Studies on cytokine signal transduction have clarified the mechanism by which IL4 exerts its functions. Two cytoplasmic proteins, signal transducer and activator of transcription (STAT) 6 and IL4-induced phosphotyrosine substrate/insulin receptor substrate 2 (4PS/IRS2), are activated in IL4 signal transduction. Recent studies from STAT6-deficient mice have revealed the essential role of STAT6 in IL4-mediated biological actions. In addition, STAT6 has also been demonstrated to be important for the functions mediated by IL13, which is related to IL4. IL4 and IL13 have been shown to induce the production of IgE, which is a major mediator in an allergic response. These findings indicate that STAT6 activation is involved in IL4- and IL13-mediated disorders such as allergy.

  7. Pyrroloquinoline-quinone and its versatile roles in biological processes

    Indian Academy of Sciences (India)

    H S Misra; Y S Rajpurohit; N P Khairnar

    2012-06-01

    Pyrroloquinoline-quinine (PQQ) was initially characterized as a redox cofactor for membrane-bound dehydrogenases in the bacterial system. Subsequently, PQQ was shown to be an antioxidant protecting the living cells from oxidative damage in vivo and the biomolecules from artificially produced reaction oxygen species in vitro. The presence of PQQ has been documented from different biological samples. It functions as a nutrient and vitamin for supporting the growth and protection of living cells under stress. Recently, the role of PQQ has also been shown as a bio-control agent for plant fungal pathogens, an inducer for proteins kinases involved in cellular differentiation of mammalian cells and as a redox sensor leading to development of biosensor. Recent reviews published on PQQ and enzymes requiring this cofactor have brought forth the case specific roles of PQQ. This review covers the comprehensive information on various aspects of PQQ known till date. These include the roles of PQQ in the regulation of cellular growth and differentiation in mammalian system, as a nutrient and vitamin in stress tolerance, in crop productivity through increasing the availability of insoluble phosphate and as a bio-control agent, and as a redox agent leading to the biosensor development. Most recent findings correlating the exceptionally high redox recycling ability of PQQ to its potential as anti-neurodegenerative, anticancer and pharmacological agents, and as a signalling molecule have been distinctly brought out. This review discusses different findings suggesting the versatility in PQQ functions and provides the most plausible intellectual basis to the ubiquitous roles of this compound in a large number of biological processes, as a nutrient and a perspective vitamin.

  8. Inactivation of Wolbachia reveals its biological roles in whitefly host.

    Science.gov (United States)

    Xue, Xia; Li, Shao-Jian; Ahmed, Muhammad Z; De Barro, Paul J; Ren, Shun-Xiang; Qiu, Bao-Li

    2012-01-01

    The whitefly Bemisia tabaci is cryptic species complex composed of numerous species. Individual species from the complex harbor a diversity of bacterial endosymbionts including Wolbachia. However, while Wolbachia is known to have a number of different roles, its role in B. tabaci is unclear. Here, the antibiotic rifampicin is used to selectively eliminate Wolbachia from B. tabaci so as to enable its roles in whitefly development and reproduction to be explored. The indirect effects of Wolbachia elimination on the biology of Encarsia bimaculata, a dominant parasitoid of B. tabaci in South China, were also investigated. qRT-PCR and FISH were used to show that after 48 h exposure to 1.0 mg/ml rifampicin, Wolbachia was completely inactivated from B. tabaci Mediterranean (MED) without any significant impact on either the primary symbiont, Portiera aleyrodidarum or any of the other secondary endosymbionts present. For B. tabaci MED, Wolbachia was shown to be associated with decreased juvenile development time, increased likelihood that nymphs completed development, increased adult life span and increased percentage of female progeny. Inactivation was associated with a significant decrease in the body size of the 4(th) instar which leads us to speculate as to whether Wolbachia may have a nutrient supplementation role. The reduction in nymph body size has consequences for its parasitoid, E. bimaculata. The elimination of Wolbachia lead to a marked increase in the proportion of parasitoid eggs that completed their development, but the reduced size of the whitefly host was also associated with a significant reduction in the size of the emerging parasitoid adult and this was in turn associated with a marked reduction in adult parasitoid longevity. Wolbachia increases the fitness of the whitefly host and provides some protection against parasitization. These observations add to our understanding of the roles played by bacterial endosymbionts.

  9. Scavenger Receptors: Emerging Roles in Cancer Biology and Immunology.

    Science.gov (United States)

    Yu, Xiaofei; Guo, Chunqing; Fisher, Paul B; Subjeck, John R; Wang, Xiang-Yang

    2015-01-01

    Scavenger receptors constitute a large family of evolutionally conserved protein molecules that are structurally and functionally diverse. Although scavenger receptors were originally identified based on their capacity to scavenge modified lipoproteins, these molecules have been shown to recognize and bind to a broad spectrum of ligands, including modified and unmodified host-derived molecules or microbial components. As a major subset of innate pattern recognition receptors, scavenger receptors are mainly expressed on myeloid cells and function in a wide range of biological processes, such as endocytosis, adhesion, lipid transport, antigen presentation, and pathogen clearance. In addition to playing a crucial role in maintenance of host homeostasis, scavenger receptors have been implicated in the pathogenesis of a number of diseases, e.g., atherosclerosis, neurodegeneration, or metabolic disorders. Emerging evidence has begun to reveal these receptor molecules as important regulators of tumor behavior and host immune responses to cancer. This review summarizes our current understanding on the newly identified, distinct functions of scavenger receptors in cancer biology and immunology. The potential of scavenger receptors as diagnostic biomarkers and novel targets for therapeutic interventions to treat malignancies is also highlighted.

  10. Dual Roles of IL-27 in Cancer Biology and Immunotherapy

    Science.gov (United States)

    Fabbi, Marina; Carbotti, Grazia

    2017-01-01

    IL-27 is a pleiotropic two-chain cytokine, composed of EBI3 and IL-27p28 subunits, which is structurally related to both IL-12 and IL-6 cytokine families. IL-27 acts through a heterodimer receptor consisting of IL-27Rα (WSX1) and gp130 chains, which mediate signaling predominantly through STAT1 and STAT3. IL-27 was initially reported as an immune-enhancing cytokine that supports CD4+ T cell proliferation, T helper (Th)1 cell differentiation, and IFN-γ production, acting in concert with IL-12. However, subsequent studies demonstrated that IL-27 displays complex immune-regulatory functions, which may result in either proinflammatory or anti-inflammatory effects in relationship to the biological context and experimental models considered. Several pieces of evidence, obtained in preclinical tumor models, indicated that IL-27 has a potent antitumor activity, related not only to the induction of tumor-specific Th1 and cytotoxic T lymphocyte (CTL) responses but also to direct inhibitory effects on tumor cell proliferation, survival, invasiveness, and angiogenic potential. Nonetheless, given its immune-regulatory functions, the effects of IL-27 on cancer may be dual and protumor effects may also occur. Here, we will summarize IL-27 biological activities and its functional overlaps with the IFNs and discuss its dual role in tumors in the light of potential applications to cancer immunotherapy. PMID:28255204

  11. Glycosides from Marine Sponges (Porifera, Demospongiae: Structures, Taxonomical Distribution, Biological Activities and Biological Roles

    Directory of Open Access Journals (Sweden)

    Valentin A. Stonik

    2012-08-01

    Full Text Available Literature data about glycosides from sponges (Porifera, Demospongiae are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

  12. Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

    Science.gov (United States)

    Kalinin, Vladimir I; Ivanchina, Natalia V; Krasokhin, Vladimir B; Makarieva, Tatyana N; Stonik, Valentin A

    2012-08-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

  13. Non-replicating Mycobacterium tuberculosis elicits a reduced infectivity profile with corresponding modifications to the cell wall and extracellular matrix.

    Directory of Open Access Journals (Sweden)

    Joanna Bacon

    Full Text Available A key feature of Mycobacterium tuberculosis is its ability to become dormant in the host. Little is known of the mechanisms by which these bacilli are able to persist in this state. Therefore, the focus of this study was to emulate environmental conditions encountered by M. tuberculosis in the granuloma, and determine the effect of such conditions on the physiology and infectivity of the organism. Non-replicating persistent (NRP M. tuberculosis was established by the gradual depletion of nutrients in an oxygen-replete and controlled environment. In contrast to rapidly dividing bacilli, NRP bacteria exhibited a distinct phenotype by accumulating an extracellular matrix rich in free mycolate and lipoglycans, with increased arabinosylation. Microarray studies demonstrated a substantial down-regulation of genes involved in energy metabolism in NRP bacteria. Despite this reduction in metabolic activity, cells were still able to infect guinea pigs, but with a delay in the development of disease when compared to exponential phase bacilli. Using these approaches to investigate the interplay between the changing environment of the host and altered physiology of NRP bacteria, this study sheds new light on the conditions that are pertinent to M. tuberculosis dormancy and how this organism could be establishing latent disease.

  14. Modern Therapies for Idiopathic Inflammatory Myopathies (IIMs): Role of Biologics.

    Science.gov (United States)

    Moghadam-Kia, Siamak; Oddis, Chester V; Aggarwal, Rohit

    2017-02-01

    Despite the lack of placebo-controlled trials, glucocorticoids are considered the mainstay of initial treatment for idiopathic inflammatory myopathy (IIMs) and myositis-associated ILD (MA-ILD). Glucocorticoid-sparing agents are often given concomitantly with other immunosuppressive agents, particularly in patients with moderate or severe disease. As treatment of refractory cases of idiopathic inflammatory myopathies has been challenging, there is growing interest in evaluating newer therapies including biologics that target various pathways involved in the pathogenesis of IIMs. In a large clinical trial of rituximab in adult and juvenile myositis, the primary outcome was not met, but the definition of improvement was met by most of this refractory group of myositis patients. Rituximab use was also associated with a significant glucocorticoid-sparing effect. Intravenous immune globulin (IVIg) can be used for refractory IIMs or those with severe dysphagia or concomitant infections. Anti-tumor necrosis factor (anti-TNF) utility in IIMs is generally limited by previous negative studies along with recent reports suggesting their potential for inducing myositis. Further research is required to assess the role of new therapies such as tocilizumab (anti-IL6), ACTH gel, sifalimumab (anti-IFNα), and abatacept (inhibition of T cell co-stimulation) given their biological plausibility and encouraging small case series results. Other potential novel therapies include alemtuzumab (a humanized monoclonal antibody which binds CD52 on B and T lymphocytes), fingolimod (a sphingosine 1-phosphate receptor modulator that traps T lymphocytes in the lymphoid organs), eculizumab, and basiliximab. The future investigations in IIMs will depend on well-designed controlled clinical trials using validated consensus core set measures and improvements in myositis classification schemes based on serologic and histopathologic features.

  15. Biology of Ageing and Role of Dietary Antioxidants

    Directory of Open Access Journals (Sweden)

    Cheng Peng

    2014-01-01

    Full Text Available Interest in relationship between diet and ageing is growing. Research has shown that dietary calorie restriction and some antioxidants extend lifespan in various ageing models. On the one hand, oxygen is essential to aerobic organisms because it is a final electron acceptor in mitochondria. On the other hand, oxygen is harmful because it can continuously generate reactive oxygen species (ROS, which are believed to be the factors causing ageing of an organism. To remove these ROS in cells, aerobic organisms possess an antioxidant defense system which consists of a series of enzymes, namely, superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPx, and glutathione reductase (GR. In addition, dietary antioxidants including ascorbic acid, vitamin A, vitamin C, α-tocopherol, and plant flavonoids are also able to scavenge ROS in cells and therefore theoretically can extend the lifespan of organisms. In this connection, various antioxidants including tea catechins, theaflavins, apple polyphenols, black rice anthocyanins, and blueberry polyphenols have been shown to be capable of extending the lifespan of fruit flies. The purpose of this review is to brief the literature on modern biological theories of ageing and role of dietary antioxidants in ageing as well as underlying mechanisms by which antioxidants can prolong the lifespan with focus on fruit flies as an model.

  16. Biology of ageing and role of dietary antioxidants.

    Science.gov (United States)

    Peng, Cheng; Wang, Xiaobo; Chen, Jingnan; Jiao, Rui; Wang, Lijun; Li, Yuk Man; Zuo, Yuanyuan; Liu, Yuwei; Lei, Lin; Ma, Ka Ying; Huang, Yu; Chen, Zhen-Yu

    2014-01-01

    Interest in relationship between diet and ageing is growing. Research has shown that dietary calorie restriction and some antioxidants extend lifespan in various ageing models. On the one hand, oxygen is essential to aerobic organisms because it is a final electron acceptor in mitochondria. On the other hand, oxygen is harmful because it can continuously generate reactive oxygen species (ROS), which are believed to be the factors causing ageing of an organism. To remove these ROS in cells, aerobic organisms possess an antioxidant defense system which consists of a series of enzymes, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). In addition, dietary antioxidants including ascorbic acid, vitamin A, vitamin C, α-tocopherol, and plant flavonoids are also able to scavenge ROS in cells and therefore theoretically can extend the lifespan of organisms. In this connection, various antioxidants including tea catechins, theaflavins, apple polyphenols, black rice anthocyanins, and blueberry polyphenols have been shown to be capable of extending the lifespan of fruit flies. The purpose of this review is to brief the literature on modern biological theories of ageing and role of dietary antioxidants in ageing as well as underlying mechanisms by which antioxidants can prolong the lifespan with focus on fruit flies as an model.

  17. The role of neutron scattering in molecular and cellular biology

    Science.gov (United States)

    Worcester, D. L.

    1982-09-01

    Neutron scattering measurements of biological macromolecules and materials have provided answers to numerous questions about molecular assemblies and arrangements. Studies of ribosomes, viruses, membranes, and other biological structures are reviewed, with emphasis on the importance of both deuterium labelling and contrast variation with H2O/D2O exchange. Although many studies of biological molecules have been made using contrast variation alone, it is the deuterium labelling experiments that have provided the most precise information and answers to major biological questions. This is largely the result of the low resolution of scattering data and the consequent rapid increase of information content that specific deuterium labelling provides. Procedures for specific deuterium labelling `in vivo' are described for recent work on myelin membranes together with basic aspects of such labelling useful for future research.

  18. Biologics: the role of delivery systems in improved therapy

    Directory of Open Access Journals (Sweden)

    Škalko-Basnet N

    2014-03-01

    Full Text Available Nataša Škalko-Basnet Drug Transport and Delivery Research Group, Department of Pharmacy, University of Tromsø, Tromsø, Norway Abstract: The beginning of the 21st century saw numerous protein and peptide therapeuticals both on the market and entering the final stages of clinical studies. They represent a new category of biologically originated drugs termed biologics or biologicals. Their main advantages over conventional drugs can be summarized by their high selectivity and potent therapeutic efficacy coupled with limited side effects. In addition, they exhibit more predictable behavior under in vivo conditions. However, up to now most of the formulations of biologics are designed and destined for the parenteral route of administration. As a consequence, many suffer from short plasma half-lives, resulting in their frequent administration and ultimately poor patient compliance. This review represents an attempt to address some of the challenges and promises in the product development of biologics both for parenteral and noninvasive administration. Some of the products currently in the pipeline of pharmaceutical development and corresponding perspectives are discussed in more detail. Keywords: biologics, drug delivery systems, medical devices

  19. The Role of Synthetic Biology in NASA's Missions

    Science.gov (United States)

    Rothschild, Lynn J.

    2016-01-01

    The time has come to for NASA to exploit synthetic biology in pursuit of its missions, including aeronautics, earth science, astrobiology and most notably, human exploration. Conversely, NASA advances the fundamental technology of synthetic biology as no one else can because of its unique expertise in the origin of life and life in extreme environments, including the potential for alternate life forms. This enables unique, creative "game changing" advances. NASA's requirement for minimizing upmass in flight will also drive the field toward miniaturization and automation. These drivers will greatly increase the utility of synthetic biology solutions for military, health in remote areas and commercial purposes. To this end, we have begun a program at NASA to explore the use of synthetic biology in NASA's missions, particular space exploration. As part of this program, we began hosting an iGEM team of undergraduates drawn from Brown and Stanford Universities to conduct synthetic biology research at NASA Ames Research Center. The 2011 team (http://2011.igem.org/Team:Brown-Stanford) produced an award-winning project on using synthetic biology as a basis for a human Mars settlement.

  20. Sustainable model building the role of standards and biological semantics.

    Science.gov (United States)

    Krause, Falko; Schulz, Marvin; Swainston, Neil; Liebermeister, Wolfram

    2011-01-01

    Systems biology models can be reused within new simulation scenarios, as parts of more complex models or as sources of biochemical knowledge. Reusability does not come by itself but has to be ensured while creating a model. Most important, models should be designed to remain valid in different contexts-for example, for different experimental conditions-and be published in a standardized and well-documented form. Creating reusable models is worthwhile, but it requires some efforts when a model is developed, implemented, documented, and published. Minimum requirements for published systems biology models have been formulated by the MIRIAM initiative. Main criteria are completeness of information and documentation, availability of machine-readable models in standard formats, and semantic annotations connecting the model elements with entries in biological Web resources. In this chapter, we discuss the assumptions behind bottom-up modeling; present important standards like MIRIAM, the Systems Biology Markup Language (SBML), and the Systems Biology Graphical Notation (SBGN); and describe software tools and services for handling semantic annotations. Finally, we show how standards can facilitate the construction of large metabolic network models.

  1. Evidence for a Role of Executive Functions in Learning Biology

    Science.gov (United States)

    Rhodes, Sinéad M.; Booth, Josephine N.; Campbell, Lorna Elise; Blythe, Richard A.; Wheate, Nial J.; Delibegovic, Mirela

    2014-01-01

    Research examining cognition and science learning has focused on working memory, but evidence implicates a broader set of executive functions. The current study examined executive functions and learning of biology in young adolescents. Fifty-six participants, aged 12-13?years, completed tasks of working memory (Spatial Working Memory), inhibition…

  2. Role of natural product diversity in chemical biology.

    Science.gov (United States)

    Hong, Jiyong

    2011-06-01

    Through the natural selection process, natural products possess a unique and vast chemical diversity and have been evolved for optimal interactions with biological macromolecules. Owing to their diversity, target affinity, and specificity, natural products have demonstrated enormous potential as modulators of biomolecular function, been an essential source for drug discovery, and provided design principles for combinatorial library development.

  3. Polysaccharies of higher fungi: Biological role, structure and antioxidative activity

    NARCIS (Netherlands)

    Kozarski, M.S.; Klaus, A.; Niksic, M.; Griensven, van L.J.L.D.; Vrvic, M.M.; Jakovljevic, D.M.

    2014-01-01

    The fungal polysaccharides attract a lot of attention due to their multiple challenging bio-logical properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypo-lipidemic, immunomodulatory and immune-stimulatory activities, which all together make them suitable for application

  4. The role of depressed metabolism in space biology: An overview

    Science.gov (United States)

    Saunders, J.

    1973-01-01

    Organization and research activities of the entire NASA Space Biology Program are outlined. Various technical approaches are reported to study depressed metabolism particularly in the situation of 100% oxygen and reduced ambient pressures. These include hibernation and hypothermia, thermal regulation, and diluent gases.

  5. Healthy aging and disease : role for telomere biology?

    NARCIS (Netherlands)

    Zhu, Haidong; Belcher, Matthew; van der Harst, Pim

    2011-01-01

    Aging is a biological process that affects most cells, organisms and species. Human aging is associated with increased susceptibility to a variety of chronic diseases, including cardiovascular disease, Type 2 diabetes, neurological diseases and cancer. Despite the remarkable progress made during the

  6. The role of analytical sciences in medical systems biology

    NARCIS (Netherlands)

    Greef, J. van der; Stroobant, P.; Heijden, R. van der

    2004-01-01

    Medical systems biology has generated widespread interest because of its bold conception and exciting potential, but the field is still in its infancy. Although there has been tremendous progress achieved recently in generating, integrating and analysing data in the medical and pharmaceutical field,

  7. Sex Roles: Their Relationship to Cultural and Biological Determinants. [Draft].

    Science.gov (United States)

    Sigmon, Scott B.

    This paper examines relevant research in comparative sociology, social anthropology with primitive societies, the behavior of primates, the hormonal control of social behavior, and contemporary social psychology. The reciprocal influence of social and biological factors on human societies is discussed. Moreover, the effect of attitudes on social…

  8. Polysaccharides of higher fungi: Biological role, structure, and antioxidative activity

    Directory of Open Access Journals (Sweden)

    Kozarski Maja S.

    2014-01-01

    Full Text Available Fungal polysaccharides attract a lot of attention due to their multiple challenging biological properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypolipidemic and immunomodulatory and immune-stimulatory activities, which all together make them suitable for application in many quite distinctive areas, such as food industry, biomedicine, cosmetology, agriculture, environmental protection and waste water management. This article presents results with respect to biological properties, structure and procedures related to the isolation and activation of polysaccharides of higher fungi. It is considered and presented along with a review of the critical antioxidative activity and possible influence of the structural composition of polysaccharide extracts (isolated from these higher fungi upon their antioxidative properties.

  9. Systems biology and its potential role in radiobiology.

    Science.gov (United States)

    Feinendegen, Ludwig; Hahnfeldt, Philip; Schadt, Eric E; Stumpf, Michael; Voit, Eberhard O

    2008-02-01

    About a century ago, Conrad Röentgen discovered X-rays, and Henri Becquerel discovered a new phenomenon, which Marie and Pierre Curie later coined as radio-activity. Since their seminal work, we have learned much about the physical properties of radiation and its effects on living matter. Alas, the more we discover, the more we appreciate the complexity of the biological processes that are triggered by radiation exposure and eventually lead (or do not lead) to disease. Equipped with modern biological methods of high-throughput experimentation, imaging, and vastly increased computational prowess, we are now entering an era where we can piece some of the multifold aspects of radiation exposure and its sequelae together, and develop a more systemic understanding of radiogenic effects such as radio-carcinogenesis than has been possible in the past. It is evident from the complexity of even the known processes that such an understanding can only be gained if it is supported by mathematical models. At this point, the construction of comprehensive models is hampered both by technical inadequacies and a paucity of appropriate data. Nonetheless, some initial steps have been taken already and the generally increased interest in systems biology may be expected to speed up future progress. In this context, we discuss in this article examples of relatively small, yet very useful models that elucidate selected aspects of the effects of exposure to ionizing radiation and may shine a light on the path before us.

  10. The role of mixotrophic protists in the biological carbon pump

    Directory of Open Access Journals (Sweden)

    A. Mitra

    2013-08-01

    Full Text Available The traditional view of the planktonic foodweb describes consumption of inorganic nutrients by photo-autotrophic phytoplankton, which in turn supports zooplankton and ultimately higher trophic levels. Pathways centred on bacteria provide mechanisms for nutrient recycling. This structure lies at the foundation of most models used to explore biogeochemical cycling, functioning of the biological pump, and the impact of climate change on these processes. We suggest an alternative paradigm, which sees the bulk of the base of this foodweb supported by protist plankton (phytoplankton and microzooplankton communities that are mixotrophic – combining phototrophy and phagotrophy within a~single cell. The photoautotrophic eukaryotic plankton and their heterotrophic microzooplankton grazers dominate only within immature environments (e.g., spring bloom in temperate systems. With their flexible nutrition, mixotrophic protists dominate in more mature systems (e.g., temperate summer, established eutrophic systems and oligotrophic systems; the more stable water columns suggested under climate change may also be expected to favour these mixotrophs. We explore how such a predominantly mixotrophic structure affects microbial trophic dynamics and the biological pump. The mixotroph dominated structure differs fundamentally in its flow of energy and nutrients, with a shortened and potentially more efficient chain from nutrient regeneration to primary production. Furthermore, mixotrophy enables a direct conduit for the support of primary production from bacterial production. We show how the exclusion of an explicit mixotrophic component in studies of the pelagic microbial communities leads to a failure to capture the true dynamics of the carbon flow. In order to prevent a misinterpretation of the full implications of climate change upon biogeochemical cycling and the functioning of the biological pump, we recommend inclusion of multi-nutrient mixotroph models within

  11. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

    National Research Council Canada - National Science Library

    De Maayer, Pieter; Chan, Wai-Yin; Blom, Jochen; Venter, Stephanus N; Duffy, Brion; Smits, Theo H M; Coutinho, Teresa A

    2012-01-01

    Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts...

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

    Science.gov (United States)

    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…

  13. The Emerging Role of PEDF in Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Mina Elahy

    2012-01-01

    Full Text Available Encoded by a single gene, PEDF is a 50 kDa glycoprotein that is highly conserved and is widely expressed among many tissues. Most secreted PEDF deposits within the extracellular matrix, with cell-type-specific functions. While traditionally PEDF is known as a strong antiangiogenic factor, more recently, as this paper highlights, PEDF has been linked with stem cell biology, and there is now accumulating evidence demonstrating the effects of PEDF in a variety of stem cells, mainly in supporting stem cell survival and maintaining multipotency.

  14. The role of molecular biology in veterinary parasitology.

    Science.gov (United States)

    Prichard, R; Tait, A

    2001-07-12

    The tools of molecular biology are increasingly relevant to veterinary parasitology. The sequencing of the complete genomes of Caenorhabditis elegans and other helminths and protozoa is allowing great advances in studying the biology, and improving diagnosis and control of parasites. Unique DNA sequences provide very high levels of specificity for the diagnosis and identification of parasite species and strains, and PCR allows extremely high levels of sensitivity. New techniques, such as the use of uniquely designed molecular beacons and DNA microarrays will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies of veterinary parasites. The ability to use genome data to clone and sequence genes which when expressed will provide antigens for vaccine screening and receptors and enzymes for mechanism-based chemotherapy screening will increase our options for parasite control. In addition, DNA vaccines can have desirable characteristics, such as sustained stimulation of the host immune system compared with protein based vaccines. One of the greatest threats to parasite control has been the development of drug resistance in parasites. Our knowledge of the basis of drug resistance and our ability to monitor its development with highly sensitive and specific DNA-based assays for 'resistance'-alleles will help maintain the effectiveness of existing antiparasitic drugs and provide hope that we can maintain control of parasitic disease outbreaks.

  15. Biological effects of pulsating magnetic fields: role of solitons

    CERN Document Server

    Brizhik, Larissa

    2014-01-01

    In this paper, we analyze biological effects produced by magnetic fields in order to elucidate the physical mechanisms, which can produce them. We show that there is a chierarchy of such mechanisms and that the mutual interplay between them can result in the synergetic outcome. In particular, we analyze the biological effects of magnetic fields on soliton mediated charge transport in the redox processes in living organisms. Such solitons are described by nonlinear systems of equations and represent electrons that are self-trapped in alpha-helical polypeptides due to the moderately strong electron-lattice interaction. They represent a particular type of disssipativeless large polarons in low-dimensional systems. We show that the effective mass of solitons in the is different from the mass of free electrons, and that there is a resonant effect of the magnetic fields on the dynamics of solitons, and, hence, on charge transport that accompanies photosynthesis and respiration. These effects can result in non-therm...

  16. The role of biological clock in glucose homeostasis 

    Directory of Open Access Journals (Sweden)

    Piotr Chrościcki

    2013-06-01

    Full Text Available The mechanism of the biological clock is based on a rhythmic expression of clock genes and clock-controlled genes. As a result of their transcripto-translational associations, endogenous rhythms in the synthesis of key proteins of various physiological and metabolic processes are created. The major timekeeping mechanism for these rhythms exists in the central nervous system. The master circadian clock, localized in suprachiasmatic nucleus (SCN, regulates multiple metabolic pathways, while feeding behavior and metabolite availability can in turn regulate the circadian clock. It is also suggested that in the brain there is a food entrainable oscillator (FEO or oscillators, resulting in activation of both food anticipatory activity and hormone secretion that control digestion processes. Moreover, most cells and tissues express autonomous clocks. Maintenance of the glucose homeostasis is particularly important for the proper function of the body, as this sugar is the main source of energy for the brain, retina, erythrocytes and skeletal muscles. Thus, glucose production and utilization are synchronized in time. The hypothalamic excited orexin neurons control energy balance of organism and modulate the glucose production and utilization. Deficiency of orexin action results in narcolepsy and weight gain, whereas glucose and amino acids can affect activity of the orexin cells. Large-scale genetic studies in rodents and humans provide evidence for the involvement of disrupted clock gene expression rhythms in the pathogenesis of obesity and type 2 diabetes. In general, the current lifestyle of the developed modern societies disturbs the action of biological clock. 

  17. The role of P2X receptors in bone biology

    DEFF Research Database (Denmark)

    Jørgensen, N R; Syberg, S; Ellegaard, M

    2015-01-01

    receptors regulate bone metabolism and especially for the P2X7 receptor an impressive amount of evidence has now documented its expression in osteoblasts, osteoclasts, and osteocytes as well as important functional roles in proliferation, differentiation, and function of the cells of bone. Key evidence has...... come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...

  18. 表达IL-2的重组非复制型痘苗病毒的构建及活性检测%Construction and bioactivity detection of a recombinant non-replicating vaccinia virus expressing IL-2

    Institute of Scientific and Technical Information of China (English)

    阳静; 庞聪; 任皎; 赵莉; 王平兴; 阮力; 谭文杰; 田厚文; 让蔚清

    2015-01-01

    Objective To generate a recombinant non-replicating vaccinia virus expressing IL-2 and detect its bioactivity in vitro.Methods Based on the non-replicating vaccinia virus (Tiantan strain) vectors,recombinant virus rNTV1175IL2H6LacZ which expressed IL-2 was constructed through homologous recombination and purified by blue-white screening.Then objective gene and protein expression was identified and the bioactivity of objective protein in vitro was detected.Results Recombinant virus was identified by PCR and Western Blot indicating that IL-2 gene with 51 1bp was correctly inserted downstream TK promoter and the molecular weight of IL-2 expressed by recombinant virus rNTV1175IL2H6LacZ was about 15000 in accordance with the molecular weight of standard IL-2.The IL-2 in the culture supernatants which was secreted by CEF with rNTV1175IL2H6LacZ promoted the growth of IL-2-dependent CTLL-2 cell lines,and the biological activity was 8.79 IU/ml measured by MTT method.Conclusion Recombinant non-replicating vaccinia virus rNTV1175IL2H6LacZ could express IL-2 with biological activity in CEF.It lay the foundation of adjust research and benefited the application of IL-2 in the field of biotherapy.%目的 构建表达IL-2的重组非复制型痘苗病毒株并体外检测其生物活性.方法 以非复制型痘苗病毒天坛株为载体,通过同源重组、蓝白斑纯化筛选表达IL-2的非复制型重组痘苗病毒rNTV1175IL2H6LacZ,并通过PCR对其进行IL-2基因插入鉴定,Western Blot鉴定IL-2的表达,同时对其进行体外生物活性检测.结果 经PCR鉴定,痘苗病毒TK区7.5启动子下正确插入了IL-2基因511bp,Western Blot结果表明其表达IL-2蛋白相对分子质量大小为15000,与标准品IL-2一致.rNTV1175 IL2H6LacZ分泌表达在细胞培养液中的IL-2能使IL-2依赖CTLL-2细胞株生长,MTT法测得重组病毒表达在细胞培养液中的IL-2生物活性值为8.79 IU/ml.结论 成功构建了表达具有生物活性IL-2的重组非

  19. The role of P2X receptors in bone biology

    DEFF Research Database (Denmark)

    Jørgensen, N R; Syberg, S; Ellegaard, M

    2015-01-01

    come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...

  20. The Plant Polyester Cutin: Biosynthesis, Structure, and Biological Roles.

    Science.gov (United States)

    Fich, Eric A; Segerson, Nicholas A; Rose, Jocelyn K C

    2016-04-29

    Cutin, a polyester composed mostly of oxygenated fatty acids, serves as the framework of the plant cuticle. The same types of cutin monomers occur across most plant lineages, although some evolutionary trends are evident. Additionally, cutins from some species have monomer profiles that are characteristic of the related polymer suberin. Compositional differences likely have profound structural consequences, but little is known about cutin's molecular organization and architectural heterogeneity. Its biological importance is suggested by the wide variety of associated mutants and gene-silencing lines that show a disruption of cuticular integrity, giving rise to numerous physiological and developmental abnormalities. Mapping and characterization of these mutants, along with suppression of gene paralogs through RNA interference, have revealed much of the biosynthetic pathway and several regulatory factors; however, the mechanisms of cutin polymerization and its interactions with other cuticle and cell wall components are only now beginning to be resolved.

  1. Role of biological factors in etiopathogenesis of borderline personality disorder

    Directory of Open Access Journals (Sweden)

    Jolanta Rabe-Jabłońska

    2012-09-01

    Full Text Available Emotionally labile personality of borderline type (borderline personality occurs in 1-2% of individuals from general population; 75% of this group are women. Similarly to most of the other mental disorders, the borderline personality results from a combination of biological, social and psychological factors. The subject of this study is a survey of the current knowledge on biological factors of borderline personality. Most researchers are of the opinion that these personality disorders are determined genetically, with such inherited temperamental traits as: dysregulation, impulsivity, and hypersensitivity. Perhaps hereditary is also a defect within the serotonergic system, endogenous opioid system and/or dopaminergic system related to the reward system. Many researchers have recently perceived the dysfunction of endogenous opioid system as an integral component of borderline personality. There is now a lot of evidence showing that this dysfunction as well as that of the reward system may account for most of the borderline personality symptoms which constitute an involuntary attempt of stimulating the inefficient systems. This is how e.g. the presence of reckless sexual behaviours, unstable interpersonal relationships and inability to delay the reward in borderline personality is accounted for. Such observations may in the future constitute an important indication for seeking a more effective pharmacotherapy for patients with borderline personality. It is possible that in some patients the described dysfunctions may be alleviated with time. This is implied by the results of comprehensive prospective studies which show a significant regression of symptoms and improvement in functioning of most patients with borderline personality after at least several years.

  2. The role of P2X receptors in bone biology

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye; Syberg, S; Ellegaard, M

    2015-01-01

    Bone is a highly dynamic organ, being constantly modeled and remodeled in order to adapt to the changing need throughout life. Bone turnover involves the coordinated actions of bone formation and bone degradation. Over the past decade great effort has been put into the examination of how P2X...... receptors regulate bone metabolism and especially for the P2X7 receptor an impressive amount of evidence has now documented its expression in osteoblasts, osteoclasts, and osteocytes as well as important functional roles in proliferation, differentiation, and function of the cells of bone. Key evidence has...... come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...

  3. The role of P2X receptors in bone biology

    DEFF Research Database (Denmark)

    Jørgensen, N R; Syberg, S; Ellegaard, M

    2015-01-01

    receptors regulate bone metabolism and especially for the P2X7 receptor an impressive amount of evidence has now documented its expression in osteoblasts, osteoclasts, and osteocytes as well as important functional roles in proliferation, differentiation, and function of the cells of bone. Key evidence has...... come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very...... recently a report from a genetic study in multiple myeloma demonstrated that decreased P2X7 receptor function was associated with increased risk of developing multiple myeloma. In contrast, the risk of developing myeloma bone disease and subsequent vertebral fractures was increased in subjects carrying P2X...

  4. Systems Biology: The Role of Engineering in the Reverse Engineering of Biological Signaling

    Directory of Open Access Journals (Sweden)

    Pablo A. Iglesias

    2013-05-01

    Full Text Available One of the principle tasks of systems biology has been the reverse engineering of signaling networks. Because of the striking similarities to engineering systems, a number of analysis and design tools from engineering disciplines have been used in this process. This review looks at several examples including the analysis of homeostasis using control theory, the attenuation of noise using signal processing, statistical inference and the use of information theory to understand both binary decision systems and the response of eukaryotic chemotactic cells.

  5. Reelin glycoprotein: structure, biology and roles in health and disease.

    Science.gov (United States)

    Fatemi, S H

    2005-03-01

    Reelin glycoprotein is a secretory serine protease with dual roles in mammalian brain: embryologically, it guides neurons and radial glial cells to their corrected positions in the developing brain; in adult brain, Reelin is involved in a signaling pathway which underlies neurotransmission, memory formation and synaptic plasticity. Disruption of Reelin signaling pathway by mutations and selective hypermethylation of the Reln gene promoter or following various pre- or postnatal insults may lead to cognitive deficits present in neuropsychiatric disorders like autism or schizophrenia.

  6. Role of Epigenetics in Biology and Human Diseases

    OpenAIRE

    Moosavi, Azam; Ardekani, Ali Motevalizadeh

    2016-01-01

    For a long time, scientists have tried to describe disorders just by genetic or environmental factors. However, the role of epigenetics in human diseases has been considered from a half of century ago. In the last decade, this subject has attracted many interests, especially in complicated disorders such as behavior plasticity, memory, cancer, autoimmune disease, and addiction as well as neurodegenerative and psychological disorders. This review first explains the history and classification o...

  7. The Role of Magnetic Forces in Biology and Medicine

    OpenAIRE

    Roth, Bradley J.

    2011-01-01

    The Lorentz force (the force acting on currents in a magnetic field) plays an increasingly larger role in techniques to image current and conductivity. This review will summarize several applications involving the Lorentz force, including 1) magneto-acoustic imaging of current, 2) “Hall effect” imaging, 3) ultrasonically-induced Lorentz force imaging of conductivity, 4) magneto-acoustic tomography with magnetic induction, and 5) Lorentz force imaging of action currents using magnetic resonanc...

  8. Context dependence of students' views about the role of equations in understanding biology.

    Science.gov (United States)

    Watkins, Jessica; Elby, Andrew

    2013-06-01

    Students' epistemological views about biology--their ideas about what "counts" as learning and understanding biology--play a role in how they approach their courses and respond to reforms. As introductory biology courses incorporate more physics and quantitative reasoning, student attitudes about the role of equations in biology become especially relevant. However, as documented in research in physics education, students' epistemologies are not always stable and fixed entities; they can be dynamic and context-dependent. In this paper, we examine an interview with an introductory student in which she discusses the use of equations in her reformed biology course. In one part of the interview, she expresses what sounds like an entrenched negative stance toward the role equations can play in understanding biology. However, later in the interview, when discussing a different biology topic, she takes a more positive stance toward the value of equations. These results highlight how a given student can have diverse ways of thinking about the value of bringing physics and math into biology. By highlighting how attitudes can shift in response to different tasks, instructional environments, and contextual cues, we emphasize the need to attend to these factors, rather than treating students' beliefs as fixed and stable.

  9. The roles of integration in molecular systems biology.

    Science.gov (United States)

    O'Malley, Maureen A; Soyer, Orkun S

    2012-03-01

    A common way to think about scientific practice involves classifying it as hypothesis- or data-driven. We argue that although such distinctions might illuminate scientific practice very generally, they are not sufficient to understand the day-to-day dynamics of scientific activity and the development of programmes of research. One aspect of everyday scientific practice that is beginning to gain more attention is integration. This paper outlines what is meant by this term and how it has been discussed from scientific and philosophical points of view. We focus on methodological, data and explanatory integration, and show how they are connected. Then, using some examples from molecular systems biology, we will show how integration works in a range of inquiries to generate surprising insights and even new fields of research. From these examples we try to gain a broader perspective on integration in relation to the contexts of inquiry in which it is implemented. In today's environment of data-intensive large-scale science, integration has become both a practical and normative requirement with corresponding implications for meta-methodological accounts of scientific practice. We conclude with a discussion of why an understanding of integration and its dynamics is useful for philosophy of science and scientific practice in general.

  10. Role of H2S Donors in Cancer Biology.

    Science.gov (United States)

    Lee, Zheng-Wei; Deng, Lih-Wen

    2015-01-01

    Hydrogen sulfide (H2S) donors including organosulfur compounds (OSC), inorganic sulfide salts, and synthetic compounds are useful tools in studies to elucidate the effects of H2S in cancer biology. Studies using such donors have shown the ability of H2S to suppress tumor growth both in vitro and in vivo, with some of them suggesting the selectivity of its cytotoxic effects to cancer cells. In addition to promoting cancer cell death, H2S donors were also found to inhibit cancer angiogenesis and metastasis. The underlying mechanisms for the anticancer activities of H2S involve (1) cell signaling pathways, such as MAPK and STAT; (2) cell cycle regulation; (3) microRNAs regulation; and (4) cancer metabolism and pH regulation. Altogether, compiling evidences have demonstrated the great potential of using H2S donors as anticancer agents. Nevertheless, the application and development of H2S for therapy are still facing challenges as identification of molecular targets of H2S awaits further investigation.

  11. The role of Protein Kinase Cη in T cell biology

    Directory of Open Access Journals (Sweden)

    Nicholas R.J. Gascoigne

    2012-06-01

    Full Text Available Protein kinase Cη (PKCη is a member of the novel PKC subfamily, which also includes δ, ε, and θ isoforms. Compared to the other novel PKCs, the function of PKCη in the immune system is largely unknown. Several studies have started to reveal the role of PKCη, particularly in T cells. PKCη is highly expressed in T cells, and is upregulated during thymocyte positive selection. Interestingly, like the θ isoform, PKCη is also recruited to the immunological synapse that is formed between a T cell and an antigen-presenting cell. However, unlike PKCθ, which becomes concentrated to the central region of the synapse, PKCη remains in a diffuse pattern over the whole area of the synapse, suggesting distinctive roles of these two isoforms in signal transduction. Although PKCη is dispensable for thymocyte development, further analysis of PKCη− or PKCθ−deficient and double knockout mice revealed the redundancy of these two isoforms in thymocyte development. In contrast, PKCη rather than PKCθ, plays an important role for T cell homeostatic proliferation, which requires recognition of self-antigen. Another piece of evidence demonstrating that PKCη and PKCθ have isoform specific as well as redundant roles come from the analysis of CD4 to CD8 T cell ratios in the periphery of these knockout mice. Deficiency in PKCη or PKCθ had opposing effects as PKCη knockout mice had a higher ratio of CD4 to CD8 T cells compared to that of wild-type mice, whereas PKCθ-deficient mice had a lower ratio. Biochemical studies showed that calcium flux and NFκB translocation is impaired in PKCη-deficient T cells upon TCR crosslinking stimulation, a character shared with PKCθ-deficient T cells. However, unlike the case with PKCθ, the mechanistic study of PKCη is at early stage and the signaling pathways involving PKCη, at least in T cells, are essentially unknown. In this review, we will cover the topics mentioned above as well as provide some

  12. Biological Sex, Sex-Role, and Self-Actualization of College Students.

    Science.gov (United States)

    Guyot, Gary W.; Vollemaere, Erik

    Self-actualization, which involves the ultimate development of one's abilities regardless of external influences, is the basis for many personality theories. To assess the relationship between biological sex, sex role, and self-actualization, the Bem Sex Role Inventory (BSRI) and the Personal Orientation Inventory (POI) were administered to 129…

  13. The Role of Health Educators in Dealing with Biological Threats in the United States

    Science.gov (United States)

    Perez, Miguel A.; Pinzon-Perez, Helda; Sowby, Sherman

    2002-01-01

    Health educators play a key role in assisting the nation deal with and be prepared for potential biological attacks. This article summarizes information found in the literature about likely bioterrorist threats to the U.S. population and discusses the responsibilities of health educators in regard to these threats. Among the important roles health…

  14. Expression Patterns and Potential Biological Roles of Dip2a.

    Directory of Open Access Journals (Sweden)

    Luqing Zhang

    Full Text Available Disconnected (disco-interacting protein 2 homolog A is a member of the DIP2 protein family encoded by Dip2a gene. Dip2a expression pattern has never been systematically studied. Functions of Dip2a in embryonic development and adult are not known. To investigate Dip2a gene expression and function in embryo and adult, a Dip2a-LacZ mouse model was generated by insertion of β-Gal cDNA after Dip2a promoter using CRISPR/Cas9 technology. Dip2a-LacZ mouse was designed to be a lacZ reporter mouse as well as a Dip2a knockout mouse. Heterozygous mice were used to study endogenous Dip2a expression and homozygotes to study DIP2A-associated structure and function. LacZ staining indicated that Dip2a is broadly expressed in neuronal, reproductive and vascular tissues, as well as in heart, kidney, liver and lung. Results demonstrate that Dip2a is expressed in ectoderm-derived tissues in developing embryos. Adult tissues showed rich staining in neurons, mesenchymal, endothelial, smooth muscle cells and cardiomyocytes by cell types. The expression pattern highly overlaps with FSTL1 and supports previous report that DIP2A to be potential receptor of FSTL1 and its protective roles of cardiomyocytes. Broad and intense embryonic and adult expression of Dip2a has implied their multiple structural and physiological roles.

  15. Acinetobacter baumannii: biology and drug resistance - role of carbapenemases.

    Science.gov (United States)

    Nowak, Pawel; Paluchowska, Paulina

    2016-01-01

    Acinetobacter baumannii is a Gram-negative, glucose-non-fermenting, oxidase-negative coccobacillus, most commonly associated with the hospital settings. The ability to survive in adverse environmental conditions as well as high level of natural and acquired antimicrobial resistance make A. baumannii one of the most important nosocomial pathogens. While carbapenems have long been considered as antimicrobials of last-resort, the rates of clinical A. baumannii strains resistant to these antibiotics are increasing worldwide. Carbapenem resistance among A. baumannii is conferred by coexisting mechanisms including: decrease in permeability of the outer membrane, efflux pumps, production of beta-lactamases, and modification of penicillin-binding proteins. The most prevalent mechanism of carbapenem resistance among A. baumannii is associated with carbapenem-hydro-lysing enzymes that belong to Ambler class D and B beta-lactamases. In addition, there have also been reports of resistance mediated by selected Ambler class A carbapenemases among A. baumannii strains. Resistance determinants in A. baumannii are located on chromosome and plasmids, while acquisition of new mechanisms can be mediated by insertion sequences, integrons, transposons, and plasmids. Clinical relevance of carbapen-em resistance among strains isolated from infected patients, carriers and hospital environment underlines the need for carbapenemase screening. Currently available methods vary in principle, accuracy and efficiency. The techniques that deserve particular attention belong to both easily accessible unsophisticated methods as well as advanced techniques based on mass spectrometry or molecular biology. While carbapenemases limit the therapeutic options in A. baumannii infections, studies concerning novel beta-lactamase inhibitors offer a new insight into effective therapy.

  16. The Role of Pannexin 3 in Bone Biology.

    Science.gov (United States)

    Ishikawa, M; Yamada, Y

    2017-04-01

    Cell-cell and cell-matrix communications play important roles in both cell proliferation and differentiation. Gap junction proteins mediate signaling communication by exchanging small molecules and dramatically stimulating intracellular signaling pathways to determine cell fate. Vertebrates have 2 gap junction families: pannexins (Panxs) and connexins (Cxs). Unlike Cxs, the functions of Panxs are not fully understood. In skeletal formation, Panx3 and Cx43 are the most abundantly expressed gap junction proteins from each family. Panx3 is induced in the transient stage from the proliferation and differentiation of chondrocytes and osteoprogenitor cells. Panx3 regulates both chondrocyte and osteoblast differentiation via the activation of intracellular Ca(2+) signaling pathways through multiple channel activities: hemichannels, endoplasmic reticulum (ER) Ca(2+) channels, and gap junctions. Moreover, Panx3 also inhibits osteoprogenitor cell proliferation and promotes cell cycle exit through the inactivation of Wnt/β-catenin signaling and the activation of p21. Panx3-knockout (KO) mice have more severe skeletal abnormalities than those of Cx43-KO mice. A phenotypic analysis of Panx3-KO mice indicates that Panx3 regulates the terminal differentiation of chondrocytes by promoting vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP) 13. Based on the generation of Panx3(-/-); Cx43(-/-) mice, Panx3 is upstream of Cx43 in osteogenesis. Panx3 promotes Cx43 expression by regulating Wnt/β-catenin signaling and osterix expression. Further, although Panx3 can function in 3 ways, Cx43 cannot function through the ER Ca(2+) channel, only via the hemichannels and gap junction routes. In this review, we discuss the current knowledge regarding the roles of Panx3 in skeletal formation and address the potential for new therapies in the treatment of diseases and pathologies associated with Panx3, such as osteoarthritis (OA).

  17. Diacylglycerol Kinase-ε: Properties and Biological Roles

    Directory of Open Access Journals (Sweden)

    Richard M Epand

    2016-10-01

    Full Text Available In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK. All catalyze the phosphorylation of diacylglycerol (DAG to phosphatidic acid (PA. Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e.1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε,is also the only DGK devoid of a regulatory domain.DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal.DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane.DGKε is likely present in both of these membranes.DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS. This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease.Thus,DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms.DGKε homologs also contain a number of conserved sequence features that are distinctive

  18. Diacylglycerol Kinase-ε: Properties and Biological Roles

    Science.gov (United States)

    Epand, Richard M.; So, Vincent; Jennings, William; Khadka, Bijendra; Gupta, Radhey S.; Lemaire, Mathieu

    2016-01-01

    In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK). All catalyze the phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PA). Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e., 1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε, is also the only DGK devoid of a regulatory domain. DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal. DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane. DGKε is likely present in both of these membranes. DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS). This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease. Thus, DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms. DGKε homologs also contain a number of conserved sequence features that are distinctive

  19. The lichens: general considerations. Role as pollution biological indicators; Les lichens: generalites. Role comme bioindicateurs de la pollution

    Energy Technology Data Exchange (ETDEWEB)

    Rivaux, E

    1998-03-25

    After having recalled the morphology and the different classification of lichens, the author presents the main lichenous substances, in particular the depsides and the depsidones. A detailed study on the role of lichens as pollution biological indicators is given. (O.M.)

  20. Biological role of prolyl 3-hydroxylation in type IV collagen.

    Science.gov (United States)

    Pokidysheva, Elena; Boudko, Sergei; Vranka, Janice; Zientek, Keith; Maddox, Kerry; Moser, Markus; Fässler, Reinhard; Ware, Jerry; Bächinger, Hans Peter

    2014-01-07

    Collagens constitute nearly 30% of all proteins in our body. Type IV collagen is a major and crucial component of basement membranes. Collagen chains undergo several posttranslational modifications that are indispensable for proper collagen function. One of these modifications, prolyl 3-hydroxylation, is accomplished by a family of prolyl 3-hydroxylases (P3H1, P3H2, and P3H3). The present study shows that P3H2-null mice are embryonic-lethal by embryonic day 8.5. The mechanism of the unexpectedly early lethality involves the interaction of non-3-hydroxylated embryonic type IV collagen with the maternal platelet-specific glycoprotein VI (GPVI). This interaction results in maternal platelet aggregation, thrombosis of the maternal blood, and death of the embryo. The phenotype is completely rescued by producing double KOs of P3H2 and GPVI. Double nulls are viable and fertile. Under normal conditions, subendothelial collagens bear the GPVI-binding sites that initiate platelet aggregation upon blood exposure during injuries. In type IV collagen, these sites are normally 3-hydroxylated. Thus, prolyl 3-hydroxylation of type IV collagen has an important function preventing maternal platelet aggregation in response to the early developing embryo. A unique link between blood coagulation and the ECM is established. The newly described mechanism may elucidate some unexplained fetal losses in humans, where thrombosis is often observed at the maternal/fetal interface. Moreover, epigenetic silencing of P3H2 in breast cancers implies that the interaction between GPVI and non-3-hydroxylated type IV collagen might also play a role in the progression of malignant tumors and metastasis.

  1. Using microarrays to study the microenvironment in tumor biology: The crucial role of statistics

    OpenAIRE

    2008-01-01

    Microarrays represent a potentially powerful tool for better understanding the role of the microenvironment on tumor biology. To make the best use of microarray data and avoid incorrect or unsubstantiated conclusions, care must be taken in the statistical analysis. To illustrate the statistical issues involved we discuss three microarray studies related to the microenvironment and tumor biology involving: (i) prostatic stroma cells in cancer and non-cancer tissues; (ii) breast stroma and epit...

  2. Elucidating biological risk factors in suicide: role of protein kinase A

    OpenAIRE

    Dwivedi, Yogesh; Pandey, Ghanshyam N.

    2010-01-01

    Suicide is a major public health concern. Although there have been several studies of suicidal behavior that focused on the roles of psychosocial and sociocultural factors, these factors are of too little predictive value to be clinically useful. Therefore, research on the biological perspective of suicide has gained a stronghold and appears to provide a promising approach to identify biological risk factors associated with suicidal behavior. Recent studies demonstrate that an alteration in s...

  3. The languages spoken in the water body (or the biological role of cyanobacterial toxins).

    Science.gov (United States)

    Kaplan, Aaron; Harel, Moshe; Kaplan-Levy, Ruth N; Hadas, Ora; Sukenik, Assaf; Dittmann, Elke

    2012-01-01

    Although intensification of toxic cyanobacterial blooms over the last decade is a matter of growing concern due to bloom impact on water quality, the biological role of most of the toxins produced is not known. In this critical review we focus primarily on the biological role of two toxins, microcystins and cylindrospermopsin, in inter- and intra-species communication and in nutrient acquisition. We examine the experimental evidence supporting some of the dogmas in the field and raise several open questions to be dealt with in future research. We do not discuss the health and environmental implications of toxin presence in the water body.

  4. Quantifying electron transfer reactions in biological systems: what interactions play the major role?

    Science.gov (United States)

    Sjulstok, Emil; Olsen, Jógvan Magnus Haugaard; Solov'yov, Ilia A

    2015-12-22

    Various biological processes involve the conversion of energy into forms that are usable for chemical transformations and are quantum mechanical in nature. Such processes involve light absorption, excited electronic states formation, excitation energy transfer, electrons and protons tunnelling which for example occur in photosynthesis, cellular respiration, DNA repair, and possibly magnetic field sensing. Quantum biology uses computation to model biological interactions in light of quantum mechanical effects and has primarily developed over the past decade as a result of convergence between quantum physics and biology. In this paper we consider electron transfer in biological processes, from a theoretical view-point; namely in terms of quantum mechanical and semi-classical models. We systematically characterize the interactions between the moving electron and its biological environment to deduce the driving force for the electron transfer reaction and to establish those interactions that play the major role in propelling the electron. The suggested approach is seen as a general recipe to treat electron transfer events in biological systems computationally, and we utilize it to describe specifically the electron transfer reactions in Arabidopsis thaliana cryptochrome-a signaling photoreceptor protein that became attractive recently due to its possible function as a biological magnetoreceptor.

  5. Quantifying electron transfer reactions in biological systems: what interactions play the major role?

    Science.gov (United States)

    Sjulstok, Emil; Olsen, Jógvan Magnus Haugaard; Solov'Yov, Ilia A.

    2015-12-01

    Various biological processes involve the conversion of energy into forms that are usable for chemical transformations and are quantum mechanical in nature. Such processes involve light absorption, excited electronic states formation, excitation energy transfer, electrons and protons tunnelling which for example occur in photosynthesis, cellular respiration, DNA repair, and possibly magnetic field sensing. Quantum biology uses computation to model biological interactions in light of quantum mechanical effects and has primarily developed over the past decade as a result of convergence between quantum physics and biology. In this paper we consider electron transfer in biological processes, from a theoretical view-point; namely in terms of quantum mechanical and semi-classical models. We systematically characterize the interactions between the moving electron and its biological environment to deduce the driving force for the electron transfer reaction and to establish those interactions that play the major role in propelling the electron. The suggested approach is seen as a general recipe to treat electron transfer events in biological systems computationally, and we utilize it to describe specifically the electron transfer reactions in Arabidopsis thaliana cryptochrome-a signaling photoreceptor protein that became attractive recently due to its possible function as a biological magnetoreceptor.

  6. Immunogenicity, protective efficacy, and non-replicative status of the HSV-2 vaccine candidate HSV529 in mice and guinea pigs.

    Directory of Open Access Journals (Sweden)

    Marie-Clotilde Bernard

    Full Text Available HSV-2 vaccine is needed to prevent genital disease, latent infection, and virus transmission. A replication-deficient mutant virus (dl5-29 has demonstrated promising efficacy in animal models of genital herpes. However, the immunogenicity, protective efficacy, and non-replicative status of the highly purified clinical vaccine candidate (HSV529 derived from dl5-29 have not been evaluated. Humoral and cellular immune responses were measured in mice and guinea pigs immunized with HSV529. Protection against acute and recurrent genital herpes, mortality, latent infection, and viral shedding after vaginal HSV-2 infection was determined in mice or in naïve and HSV-1 seropositive guinea pigs. HSV529 replication and pathogenicity were investigated in three sensitive models of virus replication: severe combined immunodeficient (SCID/Beige mice inoculated by the intramuscular route, suckling mice inoculated by the intracranial route, and vaginally-inoculated guinea pigs. HSV529 immunization induced HSV-2-neutralizing antibody production in mice and guinea pigs. In mice, it induced production of specific HSV-2 antibodies and splenocytes secreting IFNγ or IL-5. Immunization effectively prevented HSV-2 infection in all three animal models by reducing mortality, acute genital disease severity and frequency, and viral shedding. It also reduced ganglionic viral latency and recurrent disease in naïve and HSV-1 seropositive guinea pigs. HSV529 replication/propagation was not detected in the muscles of SCID/Beige mice, in the brains of suckling mice, or in vaginal secretions of inoculated guinea pigs. These results confirm the non-replicative status, as well as its immunogenicity and efficacy in mice and guinea pigs, including HSV-1 seropositive guinea pigs. In mice, HSV529 produced Th1/Th2 characteristic immune response thought to be necessary for an effective vaccine. These results further support the clinical investigation of HSV529 in human subjects as a

  7. Immunogenicity, protective efficacy, and non-replicative status of the HSV-2 vaccine candidate HSV529 in mice and guinea pigs.

    Science.gov (United States)

    Bernard, Marie-Clotilde; Barban, Véronique; Pradezynski, Fabrine; de Montfort, Aymeric; Ryall, Robert; Caillet, Catherine; Londono-Hayes, Patricia

    2015-01-01

    HSV-2 vaccine is needed to prevent genital disease, latent infection, and virus transmission. A replication-deficient mutant virus (dl5-29) has demonstrated promising efficacy in animal models of genital herpes. However, the immunogenicity, protective efficacy, and non-replicative status of the highly purified clinical vaccine candidate (HSV529) derived from dl5-29 have not been evaluated. Humoral and cellular immune responses were measured in mice and guinea pigs immunized with HSV529. Protection against acute and recurrent genital herpes, mortality, latent infection, and viral shedding after vaginal HSV-2 infection was determined in mice or in naïve and HSV-1 seropositive guinea pigs. HSV529 replication and pathogenicity were investigated in three sensitive models of virus replication: severe combined immunodeficient (SCID/Beige) mice inoculated by the intramuscular route, suckling mice inoculated by the intracranial route, and vaginally-inoculated guinea pigs. HSV529 immunization induced HSV-2-neutralizing antibody production in mice and guinea pigs. In mice, it induced production of specific HSV-2 antibodies and splenocytes secreting IFNγ or IL-5. Immunization effectively prevented HSV-2 infection in all three animal models by reducing mortality, acute genital disease severity and frequency, and viral shedding. It also reduced ganglionic viral latency and recurrent disease in naïve and HSV-1 seropositive guinea pigs. HSV529 replication/propagation was not detected in the muscles of SCID/Beige mice, in the brains of suckling mice, or in vaginal secretions of inoculated guinea pigs. These results confirm the non-replicative status, as well as its immunogenicity and efficacy in mice and guinea pigs, including HSV-1 seropositive guinea pigs. In mice, HSV529 produced Th1/Th2 characteristic immune response thought to be necessary for an effective vaccine. These results further support the clinical investigation of HSV529 in human subjects as a prophylactic vaccine.

  8. The role of biological rates in the simulated warming effect on oceanic CO2 uptake

    Science.gov (United States)

    Cao, Long; Zhang, Han

    2017-05-01

    Marine biology plays an important role in the ocean carbon cycle. However, the effect of warming-induced changes in biological rates on oceanic CO2 uptake has been largely overlooked. We use an Earth system model of intermediate complexity to investigate the effect of temperature-induced changes in biological rates on oceanic uptake of atmospheric CO2 and compare it with the effects from warming-induced changes in CO2 solubility and ocean mixing and circulation. Under the representative CO2 concentration pathway RCP 8.5 and its extension, by year 2500, relative to the simulation without warming effect on the ocean carbon cycle, CO2-induced warming reduces cumulative oceanic CO2 uptake by 469 Pg C, of which about 20% is associated with the warming-induced change in marine biological rates. In our simulations, the bulk effect of biological-mediated changes on CO2 uptake is smaller than that mediated by changes in CO2 solubility and ocean mixing and circulation. However, warming-induced changes in individual biological rates, including phytoplankton growth, phytoplankton mortality, and detritus remineralization, are found to affect oceanic CO2 uptake by an amount greater than or comparable to that caused by changes in CO2 solubility and ocean physics. Our simulations, which include only a few temperature-dependent biological processes, demonstrate the important role of biological rates in the oceanic CO2 uptake. In reality, many more complicated biological processes are sensitive to temperature change, and their responses to warming could substantially affect oceanic uptake of atmospheric CO2.

  9. The Role of Reactive Oxygen Species (ROS in the Biological Activities of Metallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmed Abdal Dayem

    2017-01-01

    Full Text Available Nanoparticles (NPs possess unique physical and chemical properties that make them appropriate for various applications. The structural alteration of metallic NPs leads to different biological functions, specifically resulting in different potentials for the generation of reactive oxygen species (ROS. The amount of ROS produced by metallic NPs correlates with particle size, shape, surface area, and chemistry. ROS possess multiple functions in cellular biology, with ROS generation a key factor in metallic NP-induced toxicity, as well as modulation of cellular signaling involved in cell death, proliferation, and differentiation. In this review, we briefly explained NP classes and their biomedical applications and describe the sources and roles of ROS in NP-related biological functions in vitro and in vivo. Furthermore, we also described the roles of metal NP-induced ROS generation in stem cell biology. Although the roles of ROS in metallic NP-related biological functions requires further investigation, modulation and characterization of metallic NP-induced ROS production are promising in the application of metallic NPs in the areas of regenerative medicine and medical devices.

  10. Role of zooplankton in determining the efficiency of the biological carbon pump

    Science.gov (United States)

    Cavan, Emma L.; Henson, Stephanie A.; Belcher, Anna; Sanders, Richard

    2017-01-01

    The efficiency of the ocean's biological carbon pump (BCPeff - here the product of particle export and transfer efficiencies) plays a key role in the air-sea partitioning of CO2. Despite its importance in the global carbon cycle, the biological processes that control BCPeff are poorly known. We investigate the potential role that zooplankton play in the biological carbon pump using both in situ observations and model output. Observed and modelled estimates of fast, slow, and total sinking fluxes are presented from three oceanic sites: the Atlantic sector of the Southern Ocean, the temperate North Atlantic, and the equatorial Pacific oxygen minimum zone (OMZ). We find that observed particle export efficiency is inversely related to primary production likely due to zooplankton grazing, in direct contrast to the model estimates. The model and observations show strongest agreement in remineralization coefficients and BCPeff at the OMZ site where zooplankton processing of particles in the mesopelagic zone is thought to be low. As the model has limited representation of zooplankton-mediated remineralization processes, we suggest that these results point to the importance of zooplankton in setting BCPeff, including particle grazing and fragmentation, and the effect of diel vertical migration. We suggest that improving parameterizations of zooplankton processes may increase the fidelity of biogeochemical model estimates of the biological carbon pump. Future changes in climate such as the expansion of OMZs may decrease the role of zooplankton in the biological carbon pump globally, hence increasing its efficiency.

  11. Investigating the role of retinal Müller cells with approaches in genetics and cell biology.

    Science.gov (United States)

    Fu, Suhua; Zhu, Meili; Ash, John D; Wang, Yunchang; Le, Yun-Zheng

    2014-01-01

    Müller cells are major macroglia and play many essential roles as a supporting cell in the retina. As Müller cells only constitute a small portion of retinal cells, investigating the role of Müller glia in retinal biology and diseases is particularly challenging. To overcome this problem, we first generated a Cre/lox-based conditional gene targeting system that permits the genetic manipulation and functional dissection of gene of interests in Müller cells. To investigate diabetes-induced alteration of Müller cells, we recently adopted methods to analyze Müller cells survival/death in vitro and in vivo. We also used normal and genetically altered primary cell cultures to reveal the mechanistic insights for Müller cells in biological and disease processes. In this article, we will discuss the applications and limitations of these methodologies, which may be useful for research in retinal Müller cell biology and pathophysiology.

  12. Role of the Ubiquitin-Proteasome Systems in the Biology and Virulence of Protozoan Parasites

    Directory of Open Access Journals (Sweden)

    Christian Muñoz

    2015-01-01

    Full Text Available In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. The catalytic heart of these complexes, the 20S proteasome, is highly conserved in bacteria, yeast, and humans. However, until a few years ago, the role of proteasomes in parasite biology was completely unknown. Here, we summarize findings about the role of proteasomes in protozoan parasites biology and virulence. Several reports have confirmed the role of proteasomes in parasite biological processes such as cell differentiation, cell cycle, proliferation, and encystation. Proliferation and cell differentiation are key steps in host colonization. Considering the importance of proteasomes in both processes in many different parasites such as Trypanosoma, Leishmania, Toxoplasma, and Entamoeba, parasite proteasomes might serve as virulence factors. Several pieces of evidence strongly suggest that the ubiquitin-proteasome pathway is also a viable parasitic therapeutic target. Research in recent years has shown that the proteasome is a valid drug target for sleeping sickness and malaria. Then, proteasomes are a key organelle in parasite biology and virulence and appear to be an attractive new chemotherapeutic target.

  13. Role of the Ubiquitin-Proteasome Systems in the Biology and Virulence of Protozoan Parasites.

    Science.gov (United States)

    Muñoz, Christian; San Francisco, Juan; Gutiérrez, Bessy; González, Jorge

    2015-01-01

    In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. The catalytic heart of these complexes, the 20S proteasome, is highly conserved in bacteria, yeast, and humans. However, until a few years ago, the role of proteasomes in parasite biology was completely unknown. Here, we summarize findings about the role of proteasomes in protozoan parasites biology and virulence. Several reports have confirmed the role of proteasomes in parasite biological processes such as cell differentiation, cell cycle, proliferation, and encystation. Proliferation and cell differentiation are key steps in host colonization. Considering the importance of proteasomes in both processes in many different parasites such as Trypanosoma, Leishmania, Toxoplasma, and Entamoeba, parasite proteasomes might serve as virulence factors. Several pieces of evidence strongly suggest that the ubiquitin-proteasome pathway is also a viable parasitic therapeutic target. Research in recent years has shown that the proteasome is a valid drug target for sleeping sickness and malaria. Then, proteasomes are a key organelle in parasite biology and virulence and appear to be an attractive new chemotherapeutic target.

  14. The biological and physical role of mulch in the rehabilitation of custed soil in the Sahel

    NARCIS (Netherlands)

    Mando, A.; Stroosnijder, L.

    1999-01-01

    During three consecutive years (1993–1995) a split-plot design with three replications was used to study the biological and physical role of mulch in the improvement of crusted soil water balance and its productivity in the north of Burkina Faso. The main treatment was the use of an insecticide, to

  15. The biological and physical role of mulch in the rehabilitation of custed soil in the Sahel

    NARCIS (Netherlands)

    Mando, A.; Stroosnijder, L.

    1999-01-01

    During three consecutive years (1993–1995) a split-plot design with three replications was used to study the biological and physical role of mulch in the improvement of crusted soil water balance and its productivity in the north of Burkina Faso. The main treatment was the use of an insecticide, to

  16. The (non-)replicability of regulatory resource depletion: A field report employing non-invasive brain stimulation

    Science.gov (United States)

    Martijn, Carolien; Alberts, Hugo J. E. M.; Thomson, Alix C.; David, Bastian; Kessler, Daniel

    2017-01-01

    Cognitive effort and self-control are exhausting. Although evidence is ambiguous, behavioural studies have repeatedly suggested that control-demanding tasks seem to deplete a limited cache of self-regulatory resources leading to performance degradations and fatigue. While resource depletion has indirectly been associated with a decline in right prefrontal cortex capacity, its precise neural underpinnings have not yet been revealed. This study consisted of two independent experiments, which set out to investigate the causal role of the right dorsolateral prefrontal cortex (DLPFC) in a classic dual phase depletion paradigm employing non-invasive brain stimulation. In Experiment 1 we demonstrated a general depletion effect, which was significantly eliminated by anodal transcranial Direct Current Stimulation to the right DLPFC. In Experiment 2, however, we failed to replicate the basic psychological depletion effect within a second independent sample. The dissimilar results are discussed in the context of the current ‘replication crisis’ and suggestions for future studies are offered. While our current results do not allow us to firmly argue for or against the existence of resource depletion, we outline why it is crucial to further clarify which specific external and internal circumstances lead to limited replicability of the described effect. We showcase and discuss the current inter-lab replication problem based on two independent samples tested within one research group (intra-lab). PMID:28362843

  17. Biological roles and functional mechanisms of arenavirus Z protein in viral replication.

    Science.gov (United States)

    Wang, Jialong; Danzy, Shamika; Kumar, Naveen; Ly, Hinh; Liang, Yuying

    2012-09-01

    Arenaviruses can cause severe hemorrhagic fever diseases in humans, with limited prophylactic or therapeutic measures. A small RING-domain viral protein Z has been shown to mediate the formation of virus-like particles and to inhibit viral RNA synthesis, although its biological roles in an infectious viral life cycle have not been directly addressed. By taking advantage of the available reverse genetics system for a model arenavirus, Pichinde virus (PICV), we provide the direct evidence for the essential biological roles of the Z protein's conserved residues, including the G2 myristylation site, the conserved C and H residues of RING domain, and the poorly characterized C-terminal L79 and P80 residues. Dicodon substitutions within the late (L) domain (PSAPPYEP) of the PICV Z protein, although producing viable mutant viruses, have significantly reduced virus growth, a finding suggestive of an important role for the intact L domain in viral replication. Further structure-function analyses of both PICV and Lassa fever virus Z proteins suggest that arenavirus Z proteins have similar molecular mechanisms in mediating their multiple functions, with some interesting variations, such as the role of the G2 residue in blocking viral RNA synthesis. In summary, our studies have characterized the biological roles of the Z protein in an infectious arenavirus system and have shed important light on the distinct functions of its domains in virus budding and viral RNA regulation, the knowledge of which may lead to the development of novel antiviral drugs.

  18. Student Acquisition of Biological Evolution-Related Misconceptions: The Role of Public High School Introductory Biology Teachers

    Science.gov (United States)

    Yates, Tony Brett

    2011-01-01

    In order to eliminate student misconceptions concerning biological evolution, it is important to identify their sources. The purposes of this study were to: (a) identify biological evolution-related misconceptions held by Oklahoma public high school Biology I teachers; (b) identify biological evolution-related misconceptions held by Oklahoma…

  19. The functional biology and trophic role of krill (Thysanoessa raschii) in a Greenlandic fjord

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Nielsen, Torkel Gissel; Munk, Peter

    2011-01-01

    Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the GodthAyenbsfjord (64 degrees N, 51 degrees W) SW Greenland, through a combination of fieldwork...... ration of 1% body C d(-1). Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 mu m, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory...

  20. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  1. Using analogy role-play activity in an undergraduate biology classroom to show central dogma revision.

    Science.gov (United States)

    Takemura, Masaharu; Kurabayashi, Mario

    2014-01-01

    For the study of biology in an undergraduate classroom, a classroom exercise was developed: an analogy role-play to learn mechanisms of gene transcription and protein translation (central dogma). To develop the central dogma role-play exercise, we made DNA and mRNA using paper sheets, tRNA using a wire dress hanger, and amino acids using Lego® blocks (Lego System A/S, Denmark). Students were studying in the course of mathematics, physics, or chemistry, so biology was not among their usual studies. In this exercise, students perform the central dogma role-play and respectively act out nuclear matrix proteins, a transcription factor, an RNA polymerase II, an mRNA transport protein, nuclear pore proteins, a large ribosomal subunit, a small ribosomal subunit, and several amino-acyl tRNA synthetases. Questionnaire results obtained after the activity show that this central dogma role-play analogy holds student interest in the practical molecular biological processes of transcription and translation.

  2. Towards an understanding of the painful total knee: what is the role of patient biology?

    Science.gov (United States)

    Preston, Stephen; Petrera, Massimo; Kim, Christopher; Zywiel, Michael G; Gandhi, Rajiv

    2016-12-01

    Total knee arthroplasty (TKA) remains the treatment of choice for end-stage osteoarthritis of the knee. With an aging population, the demand for TKA continues to increase, placing a significant burden on a health care system that must function with limited resources. Although generally accepted as a successful procedure, 15-30 % of patients report persistent pain following TKA. Classically, pain generators have been divided into intra-articular and extra-articular causes. However, there remains a significant subset of patients for whom pain remains unexplained. Recent studies have questioned the role of biology (inflammation) in the persistence of pain following TKA. This article aims to serve as a review of previously identified causes of knee pain following TKA, as well as to explore the potential role of biology as a predictor of pain following knee replacement surgery.

  3. The roles of biological interactions and pollutant contamination in shaping microbial benthic community structure

    OpenAIRE

    Louati, H.; Ben Said, O.; A. Soltani; Got, P; Mahmoudi, E.; Cravo-Laureau, C.; Duran, R.; Aissa, P.; Pringault, Olivier

    2013-01-01

    Biological interactions between metazoans and the microbial community play a major role in structuring food webs in aquatic sediments. Pollutants can also strongly affect the structure of meiofauna and microbial communities. This study aims investigating, in a non-contaminated sediment, the impact of meiofauna on bacteria facing contamination by a mixture of three PAHs (fluoranthene, phenanthrene and pyrene). Sediment microcosms were incubated in the presence or absence of meiofauna during 30...

  4. The role of Src kinase in the biology and pathogenesis of Acanthamoeba castellanii

    OpenAIRE

    Siddiqui Ruqaiyyah; Iqbal Junaid; Maugueret Marie-josée; Khan Naveed

    2012-01-01

    Abstract Background Acanthamoeba species are the causative agents of fatal granulomatous encephalitis in humans. Haematogenous spread is thought to be a primary step, followed by blood–brain barrier penetration, in the transmission of Acanthmaoeba into the central nervous system, but the associated molecular mechanisms remain unclear. Here, we evaluated the role of Src, a non-receptor protein tyrosine kinase in the biology and pathogenesis of Acanthamoeba. Methods Amoebistatic and amoebicidal...

  5. [Biological Role of Oligomerny Matriksny of Protein of the Cartilage in Exchange Processes Connecting Tissue].

    Science.gov (United States)

    Belova, Yu S

    2015-01-01

    In the review the literary data on studying of biological role of a oligomerny matriksny of protein of the cartilage in exchange processes connecting tissue at people and animals are provided, and also results of own researches on definition of a oligomerny matriksny of protein of the cartilage as a modern marker of a metabolism of an articulate cartilage at children from undifferentiated displaziy conjunctive tissue are briefly described.

  6. Tackling the biophysical properties of sphingolipids to decipher their biological roles.

    Science.gov (United States)

    Carreira, Ana C; Ventura, Ana E; Varela, Ana R P; Silva, Liana C

    2015-06-01

    From the most simple sphingoid bases to their complex glycosylated derivatives, several sphingolipid species were shown to have a role in fundamental cellular events and/or disease. Increasing evidence places lipid-lipid interactions and membrane structural alterations as central mechanisms underlying the action of these lipids. Understanding how these molecules exert their biological roles by studying their impact in the physical properties and organization of membranes is currently one of the main challenges in sphingolipid research. Herein, we review the progress in the state-of-the-art on the biophysical properties of sphingolipid-containing membranes, focusing on sphingosine, ceramides, and glycosphingolipids.

  7. Biological role of Piper nigrum L. (Black pepper):A review

    Institute of Scientific and Technical Information of China (English)

    Nisar Ahmad; Hina Fazal; Bilal Haider Abbasi; Shahid Farooq; Mohammad Ali; Mubarak Ali Khan

    2012-01-01

    Piper nigrum L. is considered the king of spices throughout the world due to its pungent principle piperine. Peppercorn of Piper nigrum as a whole or its active components are used in most of the food items. Different parts of Piper nigrum including secondary metabolites are also used as drug, preservative, insecticidal and larvicidal control agents. Biologically Piper nigrum is very important specie. The biological role of this specie is explained in different experiments that peppercorn and secondary metabolites of Piper nigrum can be used as Antiapoptotic, Antibacterial, Anti-Colon toxin, Antidepressant, Antifungal, Antidiarrhoeal, Anti-inflammatory, Antimutagenic, Anti-metastatic activity, Antioxidative, Antiriyretic, Antispasmodic, Antispermatogenic, Antitumor, Antithyroid, Ciprofloxacin potentiator, Cold extremities, Gastric ailments, Hepatoprotective, Insecticidal activity, Intermittent fever and Larvisidal activity. Other roles of this specie includes protection against diabetes induced oxidative stress; Piperine protect oxidation of various chemicals, decreased mitochondrial lipid peroxidation, inhibition of aryl hydroxylation, increased bioavailability of vaccine and sparteine, increase the bioavailability of active compounds, delayed elimination of antiepileptic drug, increased orocecal transit time, piperine influenced and activate the biomembrane to absorb variety of active agents, increased serum concentration, reducing mutational events, tumour inhibitory activity, Piperine inhibite mitochondrial oxidative phosphorylation, growth stimulatory activity and chemopreventive effect. This review based on the biological role of Piper nigrum can provide that the peppercorn or other parts can be used as crude drug for various diseases while the secondary metabolites such as piperine can be used for specific diseases.

  8. Elucidating biological risk factors in suicide: role of protein kinase A.

    Science.gov (United States)

    Dwivedi, Yogesh; Pandey, Ghanshyam N

    2011-06-01

    Suicide is a major public health concern. Although there have been several studies of suicidal behavior that focused on the roles of psychosocial and sociocultural factors, these factors are of too little predictive value to be clinically useful. Therefore, research on the biological perspective of suicide has gained a stronghold and appears to provide a promising approach to identify biological risk factors associated with suicidal behavior. Recent studies demonstrate that an alteration in synaptic and structural plasticity is key to affective illnesses and suicide. Signal transduction molecules play an important role in such plastic events. Protein kinase A (PKA) is a crucial enzyme in the adenylyl cyclase signal transduction pathway and is involved in regulating gene transcription, cell survival, and plasticity. In this review, we critically and comprehensively discuss the role of PKA in suicidal behavior. Because stress is an important component of suicide, we also discuss whether stress affects PKA and how this may be associated with suicidal behavior. In addition, we also discuss the functional significance of the findings regarding PKA by describing the role of important PKA substrates (i.e., Rap1, cyclic adenosine monophosphate response element binding protein, and target gene brain-derived neurotrophic factor). These studies suggest the interesting possibility that PKA and related signaling molecules may serve as important neurobiological factors in suicide and may be relevant in target-specific therapeutic interventions for these disorders.

  9. Teleology and its constitutive role for biology as the science of organized systems in nature.

    Science.gov (United States)

    Toepfer, Georg

    2012-03-01

    'Nothing in biology makes sense, except in the light of teleology'. This could be the first sentence in a textbook about the methodology of biology. The fundamental concepts in biology, e.g. 'organism' and 'ecosystem', are only intelligible given a teleological framework. Since early modern times, teleology has often been considered methodologically unscientific. With the acceptance of evolutionary theory, one popular strategy for accommodating teleological reasoning was to explain it by reference to selection in the past: functions were reconstructed as 'selected effects'. But the theory of evolution obviously presupposes the existence of organisms as organized and regulated, i.e. functional systems. Therefore, evolutionary theory cannot provide the foundation for teleology. The underlying reason for the central methodological role of teleology in biology is not its potential to offer particular forms of (evolutionary) explanations for the presence of parts, but rather an ontological one: organisms and other basic biological entities do not exist as physical bodies do, as amounts of matter with a definite form. Rather, they are dynamic systems in stable equilibrium; despite changes of their matter and form (in metabolism and metamorphosis) they maintain their identity. What remains constant in these kinds of systems is their 'organization', i.e. the causal pattern of interdependence of parts with certain effects of each part being relevant for the working of the system. Teleological analysis consists in the identification of these system-relevant effects and at the same time of the system as a whole. Therefore, the identity of biological systems cannot be specified without teleological reasoning.

  10. Chemical Biology of Hydropersulfides and Related Species: Possible Roles in Cellular Protection and Redox Signaling.

    Science.gov (United States)

    Álvarez, Lucía; Bianco, Christopher L; Toscano, John P; Lin, Joseph; Akaike, Takaaki; Fukuto, Jon M

    2017-10-01

    For >20 years, physiological signaling associated with the endogenous generation of hydrogen sulfide (H2S) has been of significant interest. Despite its presumed importance, the biochemical mechanisms associated with its actions have not been elucidated. Recent Advances: Recently it has been found that H2S-related or derived species are highly prevalent in mammalian systems and that these species may be responsible for some, if not the majority, of the biological actions attributed to H2S. One of the most prevalent and intriguing species are hydropersulfides (RSSH), which can be present at significant levels. Indeed, it appears that H2S and RSSH are intimately linked in biological systems and likely to be mutually inclusive. The fact that H2S and polysulfides such as RSSH are present simultaneously means that the biological actions previously assigned to H2S can be instead because of the presence of RSSH (or other polysulfides). Thus, it remains possible that hydropersulfides are the biological effectors, and H2S serves, to a certain extent, as a marker for persulfides and polysulfides. Addressing this possibility will to a large extent be based on the chemistry of these species. Currently, it is known that persulfides possess unique and novel chemical properties that may explain their biological prevalence. However, significantly more work will be required to establish the possible physiological roles of these species. Moreover, an understanding of the regulation of their biosynthesis and degradation will become important topics in piecing together their biology. Antioxid. Redox Signal. 00, 000-000.

  11. A Critical Role for Cysteine 57 in the Biological Functions of Selenium Binding Protein-1

    Directory of Open Access Journals (Sweden)

    Qi Ying

    2015-11-01

    Full Text Available The concentration of selenium-binding protein1 (SBP1 is often lower in tumors than in the corresponding tissue and lower levels have been associated with poor clinical outcomes. SBP1 binds tightly selenium although what role selenium plays in its biological functions remains unknown. Previous studies indicated that cysteine 57 is the most likely candidate amino acid for selenium binding. In order to investigate the role of cysteine 57 in SBP1, this amino acid was altered to a glycine and the mutated protein was expressed in human cancer cells. The SBP1 half-life, as well as the cellular response to selenite cytotoxicity, was altered by this change. The ectopic expression of SBP1GLY also caused mitochondrial damage in HCT116 cells. Taken together, these results indicated that cysteine 57 is a critical determinant of SBP1 function and may play a significant role in mitochondrial function.

  12. Multifarious roles of intrinsic disorder in proteins illustrate its broad impact on plant biology.

    Science.gov (United States)

    Sun, Xiaolin; Rikkerink, Erik H A; Jones, William T; Uversky, Vladimir N

    2013-01-01

    Intrinsically disordered proteins (IDPs) are highly abundant in eukaryotic proteomes. Plant IDPs play critical roles in plant biology and often act as integrators of signals from multiple plant regulatory and environmental inputs. Binding promiscuity and plasticity allow IDPs to interact with multiple partners in protein interaction networks and provide important functional advantages in molecular recognition through transient protein-protein interactions. Short interaction-prone segments within IDPs, termed molecular recognition features, represent potential binding sites that can undergo disorder-to-order transition upon binding to their partners. In this review, we summarize the evidence for the importance of IDPs in plant biology and evaluate the functions associated with intrinsic disorder in five different types of plant protein families experimentally confirmed as IDPs. Functional studies of these proteins illustrate the broad impact of disorder on many areas of plant biology, including abiotic stress, transcriptional regulation, light perception, and development. Based on the roles of disorder in the protein-protein interactions, we propose various modes of action for plant IDPs that may provide insight for future experimental approaches aimed at understanding the molecular basis of protein function within important plant pathways.

  13. Ectopic expression of AID in a non-B cell line triggers A:T and G:C point mutations in non-replicating episomal vectors.

    Directory of Open Access Journals (Sweden)

    Tihana Jovanic

    Full Text Available Somatic hypermutation (SHM of immunoglobulin genes is currently viewed as a two step process initiated by the deamination of deoxycytidine (C to deoxyuridine (U, catalysed by the activation induced deaminase (AID. Phase 1 mutations arise from DNA replication across the uracil residue or the abasic site, generated by the uracil-DNA glycosylase, yielding transitions or transversions at G:C pairs. Phase 2 mutations result from the recognition of the U:G mismatch by the Msh2/Msh6 complex (MutS Homologue, followed by the excision of the mismatched nucleotide and the repair, by the low fidelity DNA polymerase eta, of the gap generated by the exonuclease I. These mutations are mainly focused at A:T pairs. Whereas in activated B cells both G:C and A:T pairs are equally targeted, ectopic expression of AID was shown to trigger only G:C mutations on a stably integrated reporter gene. Here we show that when using non-replicative episomal vectors containing a GFP gene, inactivated by the introduction of stop codons at various positions, a high level of EGFP positive cells was obtained after transient expression in Jurkat cells constitutively expressing AID. We show that mutations at G:C and A:T pairs are produced. EGFP positive cells are obtained in the absence of vector replication demonstrating that the mutations are dependent only on the mismatch repair (MMR pathway. This implies that the generation of phase 1 mutations is not a prerequisite for the expression of phase 2 mutations.

  14. Functional biology and ecological role of krill in Northern marine ecosystems

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard

    Krill is an understudied key group of zooplankton, which transfers energy through the food web by linking lower and higher trophic levels. Furthermore, krill play an important role in the biological pump by transporting carbon out of the euphotic zone to depth by diel vertical migration (DVM......) and by production of fast sinking carbon-rich faecal pellets. Hence, the large schools of krill greatly influence the pelagic food web and the flux of organic matter in the sea. However, knowledge of the distribution and feeding biology in krill from northern areas is scarce, although of importance to get a better...... in regions with colder temperatures. Results from stable isotope analyses and feeding experiments show that there is an overlap in the diet of the species and that they are able to exploit several trophic levels. Trophic positions are related to available prey. However, the size of the krill seemed...

  15. The relative role of "A" level chemistry, physics and biology in the medical course.

    Science.gov (United States)

    Tomilson, R W; Clack, G B; Pettingale, K W; Anderson, J; Ryan, K C

    1977-03-01

    The performance of 209 students in the 2nd MBBS, first clinical year and final MBBS examinations has been compared retrospectively with their grades in chemistry, physics and biology at "A" level. The mean grade has also been determined for students from different social classes and secondary education. Significant differences in marks for biology were found between successful and not so successful students, especially in the pre-clinical part of the course. Significnat differences in marks and significant correlations were also found for physics but not to any great extent for chemistry. The relative role of these three basic sciences in the medical course is discussed. The suggestion is made that there is a need for a re-appraisal of the privleged position of chemistry and an unquestioned science requirement for entry to medical school.

  16. Oxidative Stress and Adipocyte Biology: Focus on the Role of AGEs

    Directory of Open Access Journals (Sweden)

    Florence Boyer

    2015-01-01

    Full Text Available Diabetes is a major health problem that is usually associated with obesity, together with hyperglycemia and increased advanced glycation endproducts (AGEs formation. Elevated AGEs elicit severe downstream consequences via their binding to receptors of AGEs (RAGE. This includes oxidative stress and oxidative modifications of biological compounds together with heightened inflammation. For example, albumin (major circulating protein undergoes increased glycoxidation with diabetes and may represent an important biomarker for monitoring diabetic pathophysiology. Despite the central role of adipose tissue in many physiologic/pathologic processes, recognition of the effects of greater AGEs formation in this tissue is quite recent within the obesity/diabetes context. This review provides a brief background of AGEs formation and adipose tissue biology and thereafter discusses the impact of AGEs-adipocyte interactions in pathology progression. Novel data are included showing how AGEs (especially glycated albumin may be involved in hyperglycemia-induced oxidative damage in adipocytes and its potential links to diabetes progression.

  17. The Role of Synthetic Biology in the Design of Microbial Cell Factories for Biofuel Production

    Science.gov (United States)

    Colin, Verónica Leticia; Rodríguez, Analía; Cristóbal, Héctor Antonio

    2011-01-01

    Insecurity in the supply of fossil fuels, volatile fuel prices, and major concerns regarding climate change have sparked renewed interest in the production of fuels from renewable resources. Because of this, the use of biodiesel has grown dramatically during the last few years and is expected to increase even further in the future. Biodiesel production through the use of microbial systems has marked a turning point in the field of biofuels since it is emerging as an attractive alternative to conventional technology. Recent progress in synthetic biology has accelerated the ability to analyze, construct, and/or redesign microbial metabolic pathways with unprecedented precision, in order to permit biofuel production that is amenable to industrial applications. The review presented here focuses specifically on the role of synthetic biology in the design of microbial cell factories for efficient production of biodiesel. PMID:22028591

  18. Developmental Programming of Obesity and Metabolic Dysfunction: Role of Prenatal Stress and Stress Biology

    Science.gov (United States)

    Entringer, Sonja; Wadhwa, Pathik D.

    2014-01-01

    Epidemiological, clinical, physiological, cellular and molecular evidence suggests the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. We propose that in addition to maternal nutrition-related processes, it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition), on brain and peripheral targets of programming of body composition, energy balance homeostasis and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate processes that may underlie the long-term effects of intrauterine stress. PMID:23887109

  19. Role of Inositol Poly-Phosphatases and Their Targets in T Cell Biology

    Directory of Open Access Journals (Sweden)

    Neetu eSrivastava

    2013-09-01

    Full Text Available T lymphocytes play a critical role in host defense in all anatomical sites including mucosal surfaces. This not only includes the effector arm of the immune system, but also regulation of immune responses in order to prevent autoimmunity. Genetic targeting of PI3K isoforms suggests that generation of PI(3,4,5P3 by PI3K plays a critical role in promoting effector T cell responses. Consequently, the 5’- and 3’-inositol poly-phosphatases SHIP1, SHIP2 and PTEN capable of targeting PI(3,4,5P3 are potential genetic determinants of T cell effector functions in vivo. In addition, the 5’-inositol poly phosphatases SHIP1 and 2 can shunt PI(3,4,5P3 to the rare but potent signaling phosphoinositide species PI(3,4P2 and thus these SHIP1/2, and the INPP4A/B enzymes that deplete PI(3,4P2 may have precise roles in T cell biology to amplify or inhibit effectors of PI3K signaling that are selectively recruited to and activated by PI(3,4P2. Here we summarize recent genetic and chemical evidence that indicates the inositol poly-phosphatases have important roles in both the effector and regulatory functions of the T cell compartment. In addition, we will discuss future genetic studies that might be undertaken to further elaborate the role of these enzymes in T cell biology as well as potential pharmaceutical manipulation of these enzymes for therapeutic purposes in disease settings where T cell function is a key in vivo target.

  20. Collagen and Its Role in predicting the Biological Behavior of Odontogenic Lesions.

    Science.gov (United States)

    Kulkarni, Pavan G; Kumari, M Aruna; Jahagirdar, Abhishek; Nandan, Srk; Reddy D, Shyam Prasad; Keerthi, M

    2017-02-01

    Odontogenic cysts and tumors have variable recurrence rates. Recurrence rate is mainly due to the activity of the epithelium. The epithelium of these lesions has been investigated extensively in regard to their role in proliferative and aggressive behavior of the lesions. However, the role of the connective tissue wall in their behavior has not been studied as extensively. Collagen is an essential part of the connective tissue as a whole and fibrous wall of cystic lesions especially. It is demonstrated by picrosirius red dye staining combined with polarization microscopy. This method permits the evaluation of the nature of the collagen fibers in addition to their thickness. A total of 56 histopathologically diagnosed cases comprising odontogenic follicle, dentigerous cyst, unicystic ameloblastoma, keratocystic odontogenic tumor (KCOT), multicystic/solid ameloblastoma, and ameloblastic carcinoma were taken and stained using picrosirius red stain and evaluated using a polarizing microscope. Collagen fibers in odontogenic follicles and dentiger-ous cysts showed predominant orange-red birefringence; fibers in unicystic ameloblastoma and KCOT showed both orange red and greenish-yellow birefringence; and fibers of multicystic/ solid ameloblastoma showed predominant greenish-yellow birefringence and ameloblastic carcinoma that showed almost complete greenish birefringence. As the biological behavior of the lesions in the spectrum studied progress toward aggressive nature, increase in immature collagen fibers is noticed. This study suggests that the nature of collagen fibers plays a pivotal role in predicting the biological behavior of odontogenic lesions. Aggressive nature of the odontogenic lesions is determined by both the epithelium and the connective tissue components (collagen). Studying the nature and type of collagen helps in predicting its biological behavior.

  1. Do field-free electromagnetic potentials play a role in biology?

    Science.gov (United States)

    Szasz, A; Vincze, G; Andocs, G; Szasz, O

    2009-01-01

    All bio-systems are imperfect dielectrics. Their general properties however cannot be described by conventional simple electrodynamics; the system is more complex. A central question in our present paper is centered on a controversial debate of the possible effect of the zero fields (only potentials exist). We show that the identical use of the "field-free," "curl-free," and "force-free" terminologies is incorrect, there have definitely different meanings. It is shown that the effective electro-dynamical parameters that describe and modify living systems are the potentials and not the fields. We discuss how the potentials have a role in biological processes even in field-free cases.

  2. Micro-masters of glioblastoma biology and therapy: increasingly recognized roles for microRNAs.

    Science.gov (United States)

    Floyd, Desiree; Purow, Benjamin

    2014-05-01

    MicroRNAs are small noncoding RNAs encoded in eukaryotic genomes that have been found to play critical roles in most biological processes, including cancer. This is true for glioblastoma, the most common and lethal primary brain tumor, for which microRNAs have been shown to strongly influence cell viability, stem cell characteristics, invasiveness, angiogenesis, metabolism, and immune evasion. Developing microRNAs as prognostic markers or as therapeutic agents is showing increasing promise and has potential to reach the clinic in the next several years. This succinct review summarizes current progress and future directions in this exciting and steadily expanding field.

  3. The role of biology in planetary evolution: cyanobacterial primary production in low‐oxygen Proterozoic oceans

    OpenAIRE

    Hamilton, Trinity L.; Donald A Bryant; Macalady, Jennifer L.

    2015-01-01

    Summary Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well‐preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and m...

  4. The terminal structure plays an important role in the biological activity of cecropin CMIV

    Institute of Scientific and Technical Information of China (English)

    窦非; 谢维; 董雪吟; 徐贤秀

    1999-01-01

    Antibacterial peptides have received increasing attention as a new pharmaceutical substance. But the molecular mechanism of lysis is still poorly understood. CMIV gene and mutant CMIV gene in GST fusion system were expressed. After cleaving with different cleavage reagents, the peptide with an excess of N-terminus and with an un-amidated C-terminus stopped the activity while the peptide with an excess Asn at the C-terminus had the activity level the same as natural CMIV. The results showed that the terminal structure of cecropin CMIV played an important role in its biological activity.

  5. Chromatin diminution in Copepoda (Crustacea: pattern, biological role and evolutionary aspects

    Directory of Open Access Journals (Sweden)

    Andrey Grishanin

    2014-01-01

    Full Text Available This article provides an overview of research on chromatin diminution (CD in copepods. The phenomenology, mechanisms and biological role of CD are discussed. A model of CD as an alternative means of regulating cell differentiation is presented. While the vast majority of eukaryotes inactivate genes that are no longer needed in development by heterochromatinization, copepods probably use CD for the same purpose. It is assumed that the copepods have exploited CD as a tool for adaptation to changing environmental conditions and as a mechanism for regulating the rate of evolutionary processes.

  6. Calcium-independent phospholipases A2 and their roles in biological processes and diseases

    OpenAIRE

    Ramanadham, Sasanka; Ali, Tomader; Ashley, Jason W.; Bone, Robert N.; Hancock, William D.; Lei, Xiaoyong

    2015-01-01

    Among the family of phospholipases A2 (PLA2s) are the Ca2+-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or patatin-like phospholipases (PNPLAs) are intracellular enzymes that do not require Ca2+ for activity, and contain lipase (GXSXG) and nucleotide-binding (GXGXXG) consensus sequences. T...

  7. The Role of RhoJ in Endothelial Cell Biology and Tumor Pathology

    Science.gov (United States)

    Shi, Ting-Ting; Li, Gang

    2016-01-01

    Background. RhoJ, an endothelially expressed member of Cdc42 (cell division cycle 42) subfamily of Rho GTPase, plays an important role in endocytic pathway, adipocyte differentiation, endothelial motility, tube formation, and focal adhesion. RhoJ is a selective and effective therapeutic target in tumor tissues or retinopathy. Methods. A systematic review was related to “small Rho GTPase” or “RhoJ” with “endothelial motility, tube formation and focal adhesion” and “tumor therapy”. This led to many cross-references involving RhoJ and these data have been incorporated into the following study. Results. We have grouped the role of RhoJ according to three main effects: RhoJ regulates endocytic pathway and adipocyte differentiation in early studies, and RhoJ shows an important role in endothelial cell biology; furthermore, RhoJ blockade serves as a target in tumor vasculature and enhances the effects of anticancer drug. Conclusions. More research is necessary to understand the role of RhoJ in many aspects, on the basis of current knowledge of the role of RhoJ blockade in tumor vessels, there are opportunities for the therapy of tumor, and RhoJ is expressed outside tumour vasculature and is involved in wound healing. Taking advantage of the opportunities could result in a development in tumor therapy. PMID:27556037

  8. Oligopeptides as biomarkers of cyanobacterial subpopulations. Toward an understanding of their biological role.

    Science.gov (United States)

    Agha, Ramsy; Quesada, Antonio

    2014-06-23

    Cyanobacterial oligopeptides comprise a wide range of bioactive and/or toxic compounds. While current research is strongly focused on exploring new oligopeptide variants and their bioactive properties, the biological role of these compounds remains elusive. Oligopeptides production abilities show a remarkably patchy distribution among conspecific strains. This observation has prompted alternative approaches to unveil their adaptive value, based on the use of cellular oligopeptide compositions as biomarkers of intraspecific subpopulations or chemotypes in freshwater cyanobacteria. Studies addressing the diversity, distribution, and dynamics of chemotypes in natural systems have provided important insights into the structure and ecology of cyanobacterial populations and the adaptive value of oligopeptides. This review presents an overview of the fundamentals of this emerging approach and its most relevant findings, and discusses our current understanding of the role of oligopeptides in the ecology of cyanobacteria.

  9. Roles of p53 in Various Biological Aspects of Hematopoietic Stem Cells

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    Takenobu Nii

    2012-01-01

    Full Text Available Hematopoietic stem cells (HSCs have the capacity to self-renew as well as to differentiate into all blood cell types, and they can reconstitute hematopoiesis in recipients with bone marrow ablation. In addition, transplantation therapy using HSCs is widely performed for the treatment of various incurable diseases such as hematopoietic malignancies and congenital immunodeficiency disorders. For the safe and successful transplantation of HSCs, their genetic and epigenetic integrities need to be maintained properly. Therefore, understanding the molecular mechanisms that respond to various cellular stresses in HSCs is important. The tumor suppressor protein, p53, has been shown to play critical roles in maintenance of “cell integrity” under stress conditions by controlling its target genes that regulate cell cycle arrest, apoptosis, senescence, DNA repair, or changes in metabolism. In this paper, we summarize recent reports that describe various biological functions of HSCs and discuss the roles of p53 associated with them.

  10. Biological roles of cysteine proteinases in the pathogenesis of Trichomonas vaginalis.

    Science.gov (United States)

    Hernández, Hilda M; Marcet, Ricardo; Sarracent, Jorge

    2014-01-01

    Human trichomonosis, infection with Trichomonas vaginalis, is the most common non-viral sexually transmitted disease in the world. The host-parasite interaction and pathophysiological processes of trichomonosis remain incompletely understood. This review focuses on the advancements reached in the area of the pathogenesis of T. vaginalis, especially in the role of the cysteine proteinases. It highlights various approaches made in this field and lists a group of trichomonad cysteine proteinases involved in diverse processes such as invasion of the mucous layer, cytoadherence, cytotoxicity, cytoskeleton disruption of red blood cells, hemolysis, and evasion of the host immune response. A better understanding of the biological roles of cysteine proteinases in the pathogenesis of this parasite could be used in the identification of new chemotherapeutic targets. An additional advantage could be the development of a vaccine in order to reduce transmission of T. vaginalis.

  11. Investigating the role that the Southern Ocean biological pump plays in determining global ocean oxygen concentrations and deoxygenation

    OpenAIRE

    Keller, David; Oschlies, Andreas

    2013-01-01

    Global ocean circulation connects marine biogeochemical cycles through the long-range transport of nutrients and oxygen with the Southern Ocean (SO) acting as a water mass crossroads. The biological pump in the SO has been shown to play an important role in these dynamics and the amount of export production is known to have a large impact on remote deep ocean nutrients and dissolved inorganic carbon. However, the role that the SO biological pump plays in determining ocean oxygen concentration...

  12. The Role of Molecular Biology in the Biomonitoring of Human Exposure to Chemicals

    Directory of Open Access Journals (Sweden)

    Balam Muñoz

    2010-11-01

    Full Text Available Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring personnel while evaluating work-related pathologies. Originally, occupational exposure to environmental toxicants was assessed using biochemical techniques to determine the presence of higher concentrations of toxic compounds in blood, urine, or other fluids or tissues; results were used to evaluate potential health risk. However, this approach only estimates the presence of a noxious chemical and its effects, but does not prevent or diminish the risk. Molecular biology methods have become very useful in occupational medicine to provide more accurate and opportune diagnostics. In this review, we discuss the role of the following common techniques: (1 Use of cell cultures; (2 evaluation of gene expression; (3 the “omic” sciences (genomics, transcriptomics, proteomics and metabolomics and (4 bioinformatics. We suggest that molecular biology has many applications in occupational health where the data can be applied to general environmental conditions.

  13. The role of molecular biology in the biomonitoring of human exposure to chemicals.

    Science.gov (United States)

    Muñoz, Balam; Albores, Arnulfo

    2010-11-12

    Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring personnel while evaluating work-related pathologies. Originally, occupational exposure to environmental toxicants was assessed using biochemical techniques to determine the presence of higher concentrations of toxic compounds in blood, urine, or other fluids or tissues; results were used to evaluate potential health risk. However, this approach only estimates the presence of a noxious chemical and its effects, but does not prevent or diminish the risk. Molecular biology methods have become very useful in occupational medicine to provide more accurate and opportune diagnostics. In this review, we discuss the role of the following common techniques: (1) Use of cell cultures; (2) evaluation of gene expression; (3) the "omic" sciences (genomics, transcriptomics, proteomics and metabolomics) and (4) bioinformatics. We suggest that molecular biology has many applications in occupational health where the data can be applied to general environmental conditions.

  14. The Role of Molecular Biology in the Biomonitoring of Human Exposure to Chemicals

    Science.gov (United States)

    Muñoz, Balam; Albores, Arnulfo

    2010-01-01

    Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring personnel while evaluating work-related pathologies. Originally, occupational exposure to environmental toxicants was assessed using biochemical techniques to determine the presence of higher concentrations of toxic compounds in blood, urine, or other fluids or tissues; results were used to evaluate potential health risk. However, this approach only estimates the presence of a noxious chemical and its effects, but does not prevent or diminish the risk. Molecular biology methods have become very useful in occupational medicine to provide more accurate and opportune diagnostics. In this review, we discuss the role of the following common techniques: (1) Use of cell cultures; (2) evaluation of gene expression; (3) the “omic” sciences (genomics, transcriptomics, proteomics and metabolomics) and (4) bioinformatics. We suggest that molecular biology has many applications in occupational health where the data can be applied to general environmental conditions. PMID:21151453

  15. Functional and molecular characterization of the role of CTCF in human embryonic stem cell biology.

    Directory of Open Access Journals (Sweden)

    Sri Kripa Balakrishnan

    Full Text Available The CCCTC-binding factor CTCF is the only known vertebrate insulator protein and has been shown to regulate important developmental processes such as imprinting, X-chromosome inactivation and genomic architecture. In this study, we examined the role of CTCF in human embryonic stem cell (hESC biology. We demonstrate that CTCF associates with several important pluripotency genes, including NANOG, SOX2, cMYC and LIN28 and is critical for hESC proliferation. CTCF depletion impacts expression of pluripotency genes and accelerates loss of pluripotency upon BMP4 induced differentiation, but does not result in spontaneous differentiation. We find that CTCF associates with the distal ends and internal sites of the co-regulated 160 kb NANOG-DPPA3-GDF3 locus. Each of these sites can function as a CTCF-dependent enhancer-blocking insulator in heterologous assays. In hESCs, CTCF exists in multisubunit protein complexes and can be poly(ADPribosylated. Known CTCF cofactors, such as Cohesin, differentially co-localize in the vicinity of specific CTCF binding sites within the NANOG locus. Importantly, the association of some cofactors and protein PARlation selectively changes upon differentiation although CTCF binding remains constant. Understanding how unique cofactors may impart specialized functions to CTCF at specific genomic locations will further illuminate its role in stem cell biology.

  16. On the biologic role of the reaction of NO with oxidized cytochrome c oxidase.

    Science.gov (United States)

    Antunes, Fernando; Boveris, Alberto; Cadenas, Enrique

    2007-10-01

    The inhibition of cytochrome c oxidase (CcOX) by nitric oxide (NO) is analyzed with a mathematical model that simulates the metabolism in vivo. The main results were the following: (a) We derived novel equations for the catalysis of CcOX that can be used to predict CcOX inhibition in any tissue for any [NO] or [O(2)]; (b) Competitive inhibition (resulting from the reversible binding of NO to reduced CcOX) emerges has the sole relevant component of CcOX inhibition under state 3 in vivo; (c) In state 4, contribution of uncompetitive inhibition (resulting from the reaction of oxidized CcOX with NO) represents a significant nonmajority fraction of inhibition, being favored by high [O(2)]; and (d) The main biologic role of the reaction between NO and oxidized CcOX is to consume NO. By reducing [NO], this reaction stimulates, rather than inhibits, respiration. Finally, we propose that the biologic role of NO as an inhibitor of CcOX is twofold: in state 4, it avoids an excessive buildup of mitochondrial membrane potential that triggers rapid production of oxidants, and in state 3, increases the efficiency of oxidative phosphorylation by increasing the ADP/O ratio, supporting the therapeutic use of NO in situations in which mitochondria are dysfunctional.

  17. Clinical review: Adiponectin biology and its role in inflammation and critical illness

    Science.gov (United States)

    2011-01-01

    Adiponectin is an adipokine first described just over a decade ago. Produced almost exclusively by adipocytes, adiponectin circulates in high concentrations in human plasma. Research into this hormone has revealed it to have insulin-sensitizing, anti-inflammatory and cardioprotective roles. This review discusses the history, biology and physiological role of adiponectin and explores its role in disease, with specific focus on adiponectin in inflammation and sepsis. It appears that an inverse relationship exists between adiponectin and inflammatory cytokines. Low levels of adiponectin have been found in critically ill patients, although data are limited in human subjects at this stage. The role of adiponectin in systemic inflammation and critical illness is not well defined. Early data suggest that plasma levels of adiponectin are decreased in critical illness. Whether this is a result of the disease process itself or whether patients with lower levels of this hormone are more susceptible to developing a critical illness is not known. This observation of lower adiponectin levels then raises the possibility of therapeutic options to increase circulating adiponectin levels. The various options for modulation of serum adiponectin (recombinant adiponectin, thiazolidinediones) are discussed. PMID:21586104

  18. Cellular and Developmental Biology of TRPM7 Channel-Kinase: Implicated Roles in Cancer

    Directory of Open Access Journals (Sweden)

    Nelson S. Yee

    2014-07-01

    Full Text Available The transient receptor potential melastatin-subfamily member 7 (TRPM7 is a ubiquitously expressed cation-permeable ion channel with intrinsic kinase activity that plays important roles in various physiological functions. Biochemical and electrophysiological studies, in combination with molecular analyses of TRPM7, have generated insights into its functions as a cellular sensor and transducer of physicochemical stimuli. Accumulating evidence indicates that TRPM7 channel-kinase is essential for cellular processes, such as proliferation, survival, differentiation, growth, and migration. Experimental studies in model organisms, such as zebrafish, mouse, and frog, have begun to elucidate the pleiotropic roles of TRPM7 during embryonic development from gastrulation to organogenesis. Aberrant expression and/or activity of the TRPM7 channel-kinase have been implicated in human diseases including a variety of cancer. Studying the functional roles of TRPM7 and the underlying mechanisms in normal cells and developmental processes is expected to help understand how TRPM7 channel-kinase contributes to pathogenesis, such as malignant neoplasia. On the other hand, studies of TRPM7 in diseases, particularly cancer, will help shed new light in the normal functions of TRPM7 under physiological conditions. In this article, we will provide an updated review of the structural features and biological functions of TRPM7, present a summary of current knowledge of its roles in development and cancer, and discuss the potential of TRPM7 as a clinical biomarker and therapeutic target in malignant diseases.

  19. The Role of Ubiquitin and Ubiquitin-Like Modification Systems in Papillomavirus Biology

    Directory of Open Access Journals (Sweden)

    Van G. Wilson

    2014-09-01

    Full Text Available Human papillomaviruses (HPVs are small DNA viruses that are important etiological agents of a spectrum of human skin lesions from benign to malignant. Because of their limited genome coding capacity they express only a small number of proteins, only one of which has enzymatic activity. Additionally, the HPV productive life cycle is intimately tied to the epithelial differentiation program and they must replicate in what are normally non-replicative cells, thus, these viruses must reprogram the cellular environment to achieve viral reproduction. Because of these limitations and needs, the viral proteins have evolved to co-opt cellular processes primarily through protein-protein interactions with critical host proteins. The ubiquitin post-translational modification system and the related ubiquitin-like modifiers constitute a widespread cellular regulatory network that controls the levels and functions of thousands of proteins, making these systems an attractive target for viral manipulation. This review describes the interactions between HPVs and the ubiquitin family of modifiers, both to regulate the viral proteins themselves and to remodel the host cell to facilitate viral survival and reproduction.

  20. The Biological Role of PI3K Pathway in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Kostas N. Syrigos

    2012-11-01

    Full Text Available Lung cancer is the primary cause of cancer-related mortality worldwide and although improvements in treatment have been achieved over the last few years, long-term survival rates for lung cancer patients remain poor. Therefore, there is an imperative need for molecularly targeted agents that will achieve long-term disease control. Numerous downstream molecular pathways, such as EGF/RAS/RAF/MEK/ERK and PI3K/AKT/mTOR are identified as having a key role in the pathogenesis of various forms of human cancer, including lung cancer. PI3K/AKT/mTOR signal pathway is an important intracellular signal transduction pathway with a significant role in cell proliferation, growth, survival, vesicle trafficking, glucose transport, and cytoskeletal organization. Aberrations in many primary and secondary messenger molecules of this pathway, including mutations and amplifications, are accounted for tumor cell proliferation, inhibition of apoptosis, angiogenesis, metastasis and resistance to chemotherapy-radiotherapy. In this review article, we investigate thoroughly the biological role of PI3K pathway in lung cancer and its contribution in the development of future therapeutic strategies.

  1. Roles of extracellular polymeric substances in enhanced biological phosphorus removal process.

    Science.gov (United States)

    Li, Wen-Wei; Zhang, Hai-Ling; Sheng, Guo-Ping; Yu, Han-Qing

    2015-12-01

    Enhanced biological phosphorus removal (EBPR) process is known to mainly rely on the ability of phosphorus-accumulating organisms to take up, transform and store excess amount of phosphorus (P) inside the cells. However, recent studies have revealed considerable accumulation of P also in the extracellular polymeric substances (EPS) of sludge, implying a non-negligible role of EPS in P removal by EBPR sludge. However, the contribution of EPS to P uptake and the forms of accumulated extracellular P vary substantially in different studies, and the underlying mechanism of P transformation and transportation in EPS remains poorly understood. This review provides a new recognition into the P removal process in EBPR system by incorporating the role of EPS. It overviews on the characteristics of P accumulation in EPS, explores the mechanism of P transformation and transportation in EBPR sludge and EPS, summarizes the main influential factors for the P-accumulation properties of EPS, and discusses the remaining knowledge gaps and needed future efforts that may lead to better understanding and use of such an EPS role for maximizing P recovery from wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Role of soil biology and soil functions in relation to land use intensity.

    Science.gov (United States)

    Bondi, Giulia; Wall, David; Bacher, Matthias; Emmet-Booth, Jeremy; Graça, Jessica; Marongiu, Irene; Creamer, Rachel

    2017-04-01

    The delivery of the ecosystem's functions is predominantly controlled by soil biology. The biology found in a gram of soil contains more than ten thousand individual species of bacteria and fungi (Torsvik et al., 1990). Understanding the role and the requirements of these organisms is essential for the protection and the sustainable use of soils. Soil biology represents the engine of all the processes occurring in the soil and it supports the ecosystem services such as: 1) nutrient mineralisation 2) plant production 3) water purification and regulation and 4) carbon cycling and storage. During the last years land management type and intensity have been identified as major drivers for microbial performance in soil. For this reason land management needs to be appropriately studied to understand the role of soil biology within this complex interplay of functions. We aimed to study whether and how land management drives soil biological processes and related functions. To reach this objective we built a land use intensity index (LUI) able to quantify the impact of the common farming practices carried out in Irish grassland soils. The LUI is derived from a detailed farmer questionnaire on grassland management practices at 38 farms distributed in the five major agro-climatic regions of Ireland defined by Holden and Brereton (2004). Soils were classified based on their drainage status according to the Irish Soil Information System by Creamer et al. (2014). This detailed questionnaire is then summarised into 3 management intensity components: (i) intensity of Fertilisation (Fi), (ii) frequency of Mowing (Mi) and (iii) intensity of Livestock Grazing (Gi). Sites were sampled to assess the impact of land management intensity on microbial community structure and enzyme behaviour in relation to nitrogen, phosphorus and carbon cycling. Preliminary results for enzymes linked to C and N cycles showed higher activity in relation to low grazing pressure (low Gi). Enzymes linked to P

  3. THE ROLE OF HALTICA SP. (COLEOPTERA: HALTICIDAE AS BIOLOGICAL CONTROL AGENT OF POLYGONUM CHINENSE

    Directory of Open Access Journals (Sweden)

    SUN JAY A

    1991-01-01

    Full Text Available The role of Haltica sp. (Coleoptera: Halticidae with emphasis on host specificity and damage potential in controlling Polygonum chinense was evaluated under laboratory condition. Starvation test of the weevil on 33 weeds and 14 crop plant species indicated that only 6 weed species were attacked: Polygonum chinense, P. nepalense, P. barbatum, P. longisetum, Ludwigia octovalvis and L. parennis with P. chinense as the most preferred host plant. Preliminary damage potential test indicated that a population of 0, 1,2 and 3 pairs of adult weevil reduced the percentage of fresh weight increment of P. chinense by 0; 46.2; 74.7 and 75.5% respectively. Field observations indicated that the larvae as well as adult weevils are potential biological control agents of P. chinense. Further studies are, however, on the host-range of this weevil.

  4. Ethical Dilemmas in the Biology Undergraduate Classroom: Role-Playing Congressional Testimony

    Directory of Open Access Journals (Sweden)

    Amy M. Wiles

    2014-09-01

    Full Text Available Students often struggle with weighing multiple sides of bioethical dilemmas. The assignment described here incorporates discussion of ethical dilemmas in an upper-level undergraduate biology course. Students are introduced to ethical dilemmas in genetics through discussion of issues in small groups. They are then polled as to what positions they take on each dilemma and are assigned to argue a side opposite of one of their choices. Each student receives a subpoena to appear before a Senate subcommittee to give testimony as an expert witness. This role-play provides students with a starting point and motivation for developing their argument as well as a way to distance themselves from their own opinions by acting as someone holding the opposite stance. At the end of the presentations, students are required to reflect on the experience.

  5. The role of micro-RNAs in hepatocellular carcinoma: from molecular biology to treatment.

    Science.gov (United States)

    D'Anzeo, Marco; Faloppi, Luca; Scartozzi, Mario; Giampieri, Riccardo; Bianconi, Maristella; Del Prete, Michela; Silvestris, Nicola; Cascinu, Stefano

    2014-05-19

    Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third leading cause of cancer deaths. microRNAs (miRNAs) are evolutionary conserved small non-coding RNA that negatively regulate gene expression and protein translation. Recent evidences have shown that they are involved in many biological processes, from development and cell-cycle regulation to apoptosis. miRNAs can behave as tumor suppressor or promoter of oncogenesis depending on the cellular function of their targets. Moreover, they are frequently dysregulated in HCC. In this review we summarize the latest findings of miRNAs regulation in HCC and their role as potentially diagnostic and prognostic biomarkers for HCC. We highlight development of miRNAs as potential therapeutic targets for HCC.

  6. Prokaryotic toxin-antitoxin systems--the role in bacterial physiology and application in molecular biology.

    Science.gov (United States)

    Bukowski, Michal; Rojowska, Anna; Wladyka, Benedykt

    2011-01-01

    Bacteria have developed multiple complex mechanisms ensuring an adequate response to environmental changes. In this context, bacterial cell division and growth are subject to strict control to ensure metabolic balance and cell survival. A plethora of studies cast light on toxin-antitoxin (TA) systems as metabolism regulators acting in response to environmental stress conditions. Many of those studies suggest direct relations between the TA systems and the pathogenic potential or antibiotic resistance of relevant bacteria. Other studies point out that TA systems play a significant role in ensuring stability of mobile genetic material. The evolutionary origin and relations between various TA systems are still a subject of a debate. The impact of toxin-antitoxin systems on bacteria physiology prompted their application in molecular biology as tools allowing cloning of some hard-to-maintain genes, plasmid maintenance and production of recombinant proteins.

  7. Ethical dilemmas in the biology undergraduate classroom: role-playing congressional testimony.

    Science.gov (United States)

    Wiles, Amy M

    2014-12-01

    Students often struggle with weighing multiple sides of bioethical dilemmas. The assignment described here incorporates discussion of ethical dilemmas in an upper-level undergraduate biology course. Students are introduced to ethical dilemmas in genetics through discussion of issues in small groups. They are then polled as to what positions they take on each dilemma and are assigned to argue a side opposite of one of their choices. Each student receives a subpoena to appear before a Senate subcommittee to give testimony as an expert witness. This role-play provides students with a starting point and motivation for developing their argument as well as a way to distance themselves from their own opinions by acting as someone holding the opposite stance. At the end of the presentations, students are required to reflect on the experience.

  8. Posttranscriptional Regulation of Splicing Factor SRSF1 and Its Role in Cancer Cell Biology

    Directory of Open Access Journals (Sweden)

    Vânia Gonçalves

    2015-01-01

    Full Text Available Over the past decade, alternative splicing has been progressively recognized as a major mechanism regulating gene expression patterns in different tissues and disease states through the generation of multiple mRNAs from the same gene transcript. This process requires the joining of selected exons or usage of different pairs of splice sites and is regulated by gene-specific combinations of RNA-binding proteins. One archetypical splicing regulator is SRSF1, for which we review the molecular mechanisms and posttranscriptional modifications involved in its life cycle. These include alternative splicing of SRSF1 itself, regulatory protein phosphorylation events, and the role of nuclear versus cytoplasmic SRSF1 localization. In addition, we resume current knowledge on deregulated SRSF1 expression in tumors and describe SRSF1-regulated alternative transcripts with functional consequences for cancer cell biology at different stages of tumor development.

  9. New Insights into the Biological Role of Mammalian ADARs; the RNA Editing Proteins

    Directory of Open Access Journals (Sweden)

    Niamh Mannion

    2015-09-01

    Full Text Available The ADAR proteins deaminate adenosine to inosine in double-stranded RNA which is one of the most abundant modifications present in mammalian RNA. Inosine can have a profound effect on the RNAs that are edited, not only changing the base-pairing properties, but can also result in recoding, as inosine behaves as if it were guanosine. In mammals there are three ADAR proteins and two ADAR-related proteins (ADAD expressed. All have a very similar modular structure; however, both their expression and biological function differ significantly. Only two of the ADAR proteins have enzymatic activity. However, both ADAR and ADAD proteins possess the ability to bind double-strand RNA. Mutations in ADARs have been associated with many diseases ranging from cancer, innate immunity to neurological disorders. Here, we will discuss in detail the domain structure of mammalian ADARs, the effects of RNA editing, and the role of ADARs in human diseases.

  10. Mutagens and carcinogens - Occurrence and role during chemical and biological evolution

    Science.gov (United States)

    Giner-Sorolla, A.; Oro, J.

    1981-01-01

    The roles of mutagenic and carcinogenic substances in early biologic evolution is examined, along with terrestrial and extraterrestrial sources of mutagens and carcinogens. UV solar radiation is noted to have served to stimulate prebiotic life while also causing harmful effects in plants and animals. Aromatic compounds have been found in meteorites, and comprise leukemogens, polycyclic hydrocarbons, and nitrasamine precursors. Other mutagenic sources are volcanoes, and the beginning of evolution with mutagenic substances is complicated by the appearance of malignancies due to the presence of carcinogens. The atmosphere of the Precambrian period contained both mutagens and early carcinogens and, combined with volcanic activity discharges, formed an atmospheric chemical background analogous to the background ionizing radiation. Carcinogenesis is concluded to be intrinsic to nature, having initiated evolution and, eventually, cancer cells.

  11. The cell biology of cross-presentation and the role of dendritic cell subsets.

    Science.gov (United States)

    Lin, Ming-Lee; Zhan, Yifan; Villadangos, Jose A; Lew, Andrew M

    2008-01-01

    The cell biology of cross-presentation is reviewed regarding exogenous antigen uptake, antigen degradation and entry into the major histocompatibility complex class I pathway. Whereas cross-presentation is not associated with enhanced phagocytic ability, certain receptors may favour uptake for cross-presentation for example mannose receptor for soluble glycoproteins. Perhaps, the defining property of the cross-presenting cell is some specialization in host machinery for handling and transport of antigen across organelles. Both cytosolic and vacuolar pathways are discussed. Which dendritic cell (DC) subset is the cross-presenting cell is explored. Cross-presentation is found within the CD8(+) subset resident in lymphoid organs. The role of other DC subsets (especially the migratory CD8(-) DC) and the route of antigen delivery are also discussed. Further consideration is given to antigen transfer between DC subsets and differential presentation to naive vs memory T cells.

  12. A systems biology approach to studying the role of microbes in human health.

    Science.gov (United States)

    Thiele, Ines; Heinken, Almut; Fleming, Ronan M T

    2013-02-01

    Host-microbe interactions play a crucial role in human health and disease. Of the various systems biology approaches, reconstruction of genome-scale metabolic networks combined with constraint-based modeling has been particularly successful at in silico predicting the phenotypic characteristics of single organisms. Here, we summarize recent studies, which have applied this approach to investigate microbe-microbe and host-microbe metabolic interactions. This approach can be also expanded to investigate the properties of an entire microbial community, as well as single organisms within the community. We illustrate that the constraint-based modeling approach is suitable to model host-microbe interactions at molecular resolution and will enable systematic investigation of metabolic links between the human host and its microbes. Such host-microbe models, combined with experimental data, will ultimately further our understanding of how microbes influence human health.

  13. Biological and physiological role of reactive oxygen species--the good, the bad and the ugly.

    Science.gov (United States)

    Zuo, L; Zhou, T; Pannell, B K; Ziegler, A C; Best, T M

    2015-07-01

    Reactive oxygen species (ROS) are chemically reactive molecules that are naturally produced within biological systems. Research has focused extensively on revealing the multi-faceted and complex roles that ROS play in living tissues. In regard to the good side of ROS, this article explores the effects of ROS on signalling, immune response and other physiological responses. To review the potentially bad side of ROS, we explain the consequences of high concentrations of molecules that lead to the disruption of redox homeostasis, which induces oxidative stress damaging intracellular components. The ugly effects of ROS can be observed in devastating cardiac, pulmonary, neurodegenerative and other disorders. Furthermore, this article covers the regulatory enzymes that mitigate the effects of ROS. Glutathione peroxidase, superoxide dismutase and catalase are discussed in particular detail. The current understanding of ROS is incomplete, and it is imperative that future research be performed to understand the implications of ROS in various therapeutic interventions.

  14. Mechanism and biological role of profilin-Srv2/CAP interaction.

    Science.gov (United States)

    Bertling, Enni; Quintero-Monzon, Omar; Mattila, Pieta K; Goode, Bruce L; Lappalainen, Pekka

    2007-04-01

    Profilin and cyclase-associated protein (CAP, known in yeast as Srv2) are ubiquitous and abundant actin monomer-binding proteins. Profilin catalyses the nucleotide exchange on actin monomers and promotes their addition to filament barbed ends. Srv2/CAP recycles newly depolymerized actin monomers from ADF/cofilin for subsequent rounds of polymerization. Srv2/CAP also harbors two proline-rich motifs and has been suggested to interact with profilin. However, the mechanism and biological role of the possible profilin-Srv2/CAP interaction has not been investigated. Here, we show that Saccharomyces cerevisiae Srv2 and profilin interact directly (K(D) approximately 1.3 microM) and demonstrate that a specific proline-rich motif in Srv2 mediates this interaction in vitro and in vivo. ADP-actin monomers and profilin do not interfere with each other's binding to Srv2, suggesting that these three proteins can form a ternary complex. Genetic and cell biological analyses on an Srv2 allele (srv2-201) defective in binding profilin reveals that a direct interaction with profilin is not essential for Srv2 cellular function. However, srv2-201 causes a moderate increase in cell size and partially suppresses the cell growth and actin organization defects of an actin binding mutant profilin (pfy1-4). Together these data suggest that Srv2 is an important physiological interaction partner of profilin.

  15. Biological role of NK cells and immunotherapeutic approaches in breast cancer

    Directory of Open Access Journals (Sweden)

    María Paula Roberti

    2012-12-01

    Full Text Available In recent decades, tumor surveillance by the immune system and its impact on disease outcomes in cancer patients in general and in breast cancer (BC patients in particular has been documented. Natural killer (NK cells are central components of the innate immunity and existing data indicate that they play a role in preventing and controlling tumor growth and metastasis. Their biological significance was first recognized by their ability to exert direct cellular cytotoxicity without prior sensitization. This is important in tumors, as transforming events are likely to result in downregulation of self-ligands and expression of stress-induced ligands which can be recognized by NK cells. Their activation also leads to secretion of stimulatory cytokines which participate in cancer elimination by several direct mechanisms as well as by stimulating the adaptive immune system. In this regard, it was recently revealed a dendritic cell (DC-NK cell crosstalk which provides another novel pathway linking innate and adaptive immunity. In addition, NK cells are feasible targets of stimulation in immunotherapeutic approaches such as antibody-based strategies and adoptive cell transfer. Nevertheless, NK cells display impaired functionality and capability to infiltrate tumors in BC patients. This review compiles information about NK cell biology in BC and the attempts which aim to manipulate them in novel therapeutic approaches in this pathology.

  16. Biological role of Interleukin 33 and its importance in pathophysiology of cardiovascular system

    Directory of Open Access Journals (Sweden)

    Agnieszka Czyżewska-Buczyńska

    2014-06-01

    Full Text Available Interleukin 33 (IL-33 is a member of the IL-1 cytokin family. It is expressed by various cells and tissues, mainly epithelial and endothelial cells. It is a cytokine with dual function. It may act both as a traditional cytokine and as intracellular nuclear factor, functioning as transcription regulator. Its biological effect via interaction with membrane-bound ST2 receptor and IL-1 receptor accessory protein (IL-1RAcP is associated with the induction of Th2-type immune response and IL-5 and IL-13 synthesis. IL-33 has a strong immunoregulatory properties. Depending on the type of activated cells, microenvironment, and costimulatory factors, IL-33 can act either as a pro- or anti-inflammatory cytokine. Recent studies indicate various protective effect of IL-33/ST2 sygnaling in atherosclerosis, obesity, disorders in glucose homeostasis and in heart diseases. The paper presents current state of knowledge about the structure and biological function of IL-33 and its receptor ST2, with particular emphasis on its role in pathophysiology of cardiovascular system.

  17. The role of biologically active peptides in tissue repair using umbilical cord mesenchymal stem cells.

    Science.gov (United States)

    Cabrera, Carlos; Carriquiry, Gabriela; Pierinelli, Chiara; Reinoso, Nancy; Arias-Stella, Javier; Paino, Javier

    2012-10-01

    The role of bioactive compounds in wound repair is critical. The preliminary work described herein includes the study of the effects of second degree burns in a Rex rabbit model and the action of human umbilical cord cells on the regulation and secretion of bioactive compounds. When applied on blood scaffolds as heterograft matrices, fibroblasts proliferate from these primary cultures and release biologically active peptides under tight control. Our work in progress indicates that mesenchymal stem cell (MSC)-mediated therapy provides better quality and more efficient burn reepithelialization of injured tissues by controlling the release of these peptides. Improvement of wound aesthetics is achieved in less time than without MSC-mediated therapy. Well-organized epidermal regeneration and overall better quality of reepithelialization, with no rejection, can be demonstrated consistently with periodic biopsies. Our studies indicate that MSCs have the capacity to produce, regulate, and deliver biologically active peptides that result in superior regeneration, compared with conventional treatments. © 2012 New York Academy of Sciences.

  18. Preparing Biology Graduate Teaching Assistants for Their Roles as Instructors: An Assessment of Institutional Approaches.

    Science.gov (United States)

    Schussler, Elisabeth E; Read, Quentin; Marbach-Ad, Gili; Miller, Kristen; Ferzli, Miriam

    2015-01-01

    The inconsistency of professional development (PD) in teaching for graduate teaching assistants (GTAs) is a widespread problem in higher education. Although GTAs serve an important role in retention of undergraduate science majors and in promotion of scientific literacy in nonmajors, they often lack preparation and ongoing support for teaching. Given the recent national focus on instructional quality in introductory courses, our goal was to use an online survey to identify current practices of teaching PD for biology GTAs and compare these results with the last national survey on this topic. In responses from 71 participant institutions, 96% reported some mandatory teaching preparation for biology GTAs; however, 52% of these programs required 10 or fewer hours per year. Respondents wanted to change their programs to include more pedagogical information and teaching observations with feedback to their GTAs. Programmatic self-ratings of satisfaction with GTA PD were positively correlated with the number of topics discussed during PD. Although more schools are requiring GTA PD for teaching compared with the last national survey, the lack of program breadth at many schools warrants a national conversation with regard to recent calls for improving undergraduate instruction.

  19. The role of genomics in the identification, prediction, and prevention of biological threats.

    Science.gov (United States)

    Fricke, W Florian; Rasko, David A; Ravel, Jacques

    2009-10-01

    In all likelihood, it is only a matter of time before our public health system will face a major biological threat, whether intentionally dispersed or originating from a known or newly emerging infectious disease. It is necessary not only to increase our reactive "biodefense," but also to be proactive and increase our preparedness. To achieve this goal, it is essential that the scientific and public health communities fully embrace the genomic revolution, and that novel bioinformatic and computing tools necessary to make great strides in our understanding of these novel and emerging threats be developed. Genomics has graduated from a specialized field of science to a research tool that soon will be routine in research laboratories and clinical settings. Because the technology is becoming more affordable, genomics can and should be used proactively to build our preparedness and responsiveness to biological threats. All pieces, including major continued funding, advances in next-generation sequencing technologies, bioinformatics infrastructures, and open access to data and metadata, are being set in place for genomics to play a central role in our public health system.

  20. The role of genomics in the identification, prediction, and prevention of biological threats.

    Directory of Open Access Journals (Sweden)

    W Florian Fricke

    2009-10-01

    Full Text Available In all likelihood, it is only a matter of time before our public health system will face a major biological threat, whether intentionally dispersed or originating from a known or newly emerging infectious disease. It is necessary not only to increase our reactive "biodefense," but also to be proactive and increase our preparedness. To achieve this goal, it is essential that the scientific and public health communities fully embrace the genomic revolution, and that novel bioinformatic and computing tools necessary to make great strides in our understanding of these novel and emerging threats be developed. Genomics has graduated from a specialized field of science to a research tool that soon will be routine in research laboratories and clinical settings. Because the technology is becoming more affordable, genomics can and should be used proactively to build our preparedness and responsiveness to biological threats. All pieces, including major continued funding, advances in next-generation sequencing technologies, bioinformatics infrastructures, and open access to data and metadata, are being set in place for genomics to play a central role in our public health system.

  1. Roles of host and viral microRNAs in human cytomegalovirus biology

    Science.gov (United States)

    Dhuruvasan, Kavitha; Sivasubramanian, Geetha; Pellett, Philip E.

    2011-01-01

    Human cytomegalovirus (HCMV) has a relatively large and complex genome, a protracted lytic replication cycle, and employs a strategy of replicational latency as part of its lifelong persistence in the infected host. An important form of gene regulation in plants and animals revolves around a type of small RNA known as microRNA (miRNA). miRNAs can serve as major regulators of key developmental pathways, as well as provide subtle forms of regulatory control. The human genome encodes over 900 miRNAs, and miRNAs are also encoded by some viruses, including HCMV, which encodes at least 14 miRNAs. Some of the HCMV miRNAs are known to target both viral and cellular genes, including important immunomodulators. In addition to expressing their own miRNAs, infections with some viruses, including HCMV, can result in changes in the expression of cellular miRNAs that benefit virus replication. In this review, we summarize the connections between miRNAs and HCMV biology. We describe the nature of miRNA genes, miRNA biogenesis and modes of action, methods for studying miRNAs, HCMV-encoded miRNAs, effects of HCMV infection on cellular miRNA expression, roles of miRNAs in HCMV biology, and possible HCMV-related diagnostic and therapeutic applications of miRNAs. PMID:20969901

  2. Preparing Biology Graduate Teaching Assistants for Their Roles as Instructors: An Assessment of Institutional Approaches

    Science.gov (United States)

    Schussler, Elisabeth E.; Read, Quentin; Marbach-Ad, Gili; Miller, Kristen; Ferzli, Miriam

    2015-01-01

    The inconsistency of professional development (PD) in teaching for graduate teaching assistants (GTAs) is a widespread problem in higher education. Although GTAs serve an important role in retention of undergraduate science majors and in promotion of scientific literacy in nonmajors, they often lack preparation and ongoing support for teaching. Given the recent national focus on instructional quality in introductory courses, our goal was to use an online survey to identify current practices of teaching PD for biology GTAs and compare these results with the last national survey on this topic. In responses from 71 participant institutions, 96% reported some mandatory teaching preparation for biology GTAs; however, 52% of these programs required 10 or fewer hours per year. Respondents wanted to change their programs to include more pedagogical information and teaching observations with feedback to their GTAs. Programmatic self-ratings of satisfaction with GTA PD were positively correlated with the number of topics discussed during PD. Although more schools are requiring GTA PD for teaching compared with the last national survey, the lack of program breadth at many schools warrants a national conversation with regard to recent calls for improving undergraduate instruction. PMID:26231562

  3. ESL students learning biology: The role of language and social interactions

    Science.gov (United States)

    Jaipal, Kamini

    This study explored three aspects related to ESL students in a mainstream grade 11 biology classroom: (1) the nature of students' participation in classroom activities, (2) the factors that enhanced or constrained ESL students' engagement in social interactions, and (3) the role of language in the learning of science. Ten ESL students were observed over an eight-month period in this biology classroom. Data were collected using qualitative research methods such as participant observation, audio-recordings of lessons, field notes, semi-structured interviews, short lesson recall interviews and students' written work. The study was framed within sociocultural perspectives, particularly the social constructivist perspectives of Vygotsky (1962, 1978) and Wertsch (1991). Data were analysed with respect to the three research aspects. Firstly, the findings showed that ESL students' preferred and exhibited a variety of participation practices that ranged from personal-individual to socio-interactive in nature. Both personal-individual and socio-interactive practices appeared to support science and language learning. Secondly, the findings indicated that ESL students' engagement in classroom social interactions was most likely influenced by the complex interactions between a number of competing factors at the individual, interpersonal and community/cultural levels (Rogoff, Radziszewska, & Masiello, 1995). In this study, six factors that appeared to enhance or constrain ESL students' engagement in classroom social interactions were identified. These factors were socio-cultural factors, prior classroom practice, teaching practices, affective factors, English language proficiency, and participation in the research project. Thirdly, the findings indicated that language played a significant mediational role in ESL students' learning of science. The data revealed that the learning of science terms and concepts can be explained by a functional model of language that includes: (1

  4. The role of DNA restriction-modification systems in the biology of Bacillus anthracis

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    Ramakrishnan eSitaraman

    2016-01-01

    Full Text Available Restriction-modification (R-M systems are widespread among prokaryotes and, depending on their type, may be viewed as selfish genetic elements that persist as toxin-antitoxin modules or as cellular defense systems against phage infection. Studies in the last decade have made it amply clear that these two options do not exhaust the list of possible biological roles for R-M systems. Their presence in a cell may also have a bearing on other processes such as horizontal gene transfer and gene regulation. From genome sequencing and experimental data, we know that Bacillus anthracis encodes at least three methylation-dependent (typeIV restriction endonucleases, and an orphan DNA methyltransferase. In this article, we first present an outline of our current knowledge of R-M systems in Bacillus anthracis. Based on available DNA sequence data, and on our current understanding of the functions of similar genes in other systems, we conclude with hypotheses on the possible roles of the three restriction endonucleases and the orphan DNA methyltransferase.

  5. Understanding the role of extracellular polymeric substances in an enhanced biological phosphorus removal granular sludge system.

    Science.gov (United States)

    Wang, Randeng; Peng, Yongzhen; Cheng, Zhanli; Ren, Nanqi

    2014-10-01

    The role of extracellular polymeric substances (EPS) in the enhanced biological phosphorus removal (EBPR) process was investigated in a P-accumulating granular sludge system by analyzing the distribution and transfer of P, K(+), Mg(2+) and Ca(2+) in the sludge phase, EPS, and the bulk liquid. In the sludge phase, about 30% P, 44.7% K(+), 27.7% Mg(2+), 28% Ca(2+) accumulated in the EPS at the end of aeration. The rate of P, K(+), Mg(2+) and Ca(2+) released from the EPS matrix into the bulk liquid in the anaerobic phase was faster than the rate they were adsorbed from the bulk liquid into the EPS in the aerobic phase. P, K(+), Mg(2+) and Ca(2+) were retained in EPS before transferring into the phosphorus accumulating organisms (PAOs). These results suggest that EPS play a critical role in facilitating the accumulation and transfer of P, K(+), Ca(2+) and Mg(2+) between PAO cells and bulk liquid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Remaining Mysteries of Molecular Biology: The Role of Polyamines in the Cell.

    Science.gov (United States)

    Miller-Fleming, Leonor; Olin-Sandoval, Viridiana; Campbell, Kate; Ralser, Markus

    2015-10-23

    The polyamines (PAs) spermidine, spermine, putrescine and cadaverine are an essential class of metabolites found throughout all kingdoms of life. In this comprehensive review, we discuss their metabolism, their various intracellular functions and their unusual and conserved regulatory features. These include the regulation of translation via upstream open reading frames, the over-reading of stop codons via ribosomal frameshifting, the existence of an antizyme and an antizyme inhibitor, ubiquitin-independent proteasomal degradation, a complex bi-directional membrane transport system and a unique posttranslational modification-hypusination-that is believed to occur on a single protein only (eIF-5A). Many of these features are broadly conserved indicating that PA metabolism is both concentration critical and evolutionary ancient. When PA metabolism is disrupted, a plethora of cellular processes are affected, including transcription, translation, gene expression regulation, autophagy and stress resistance. As a result, the role of PAs has been associated with cell growth, aging, memory performance, neurodegenerative diseases, metabolic disorders and cancer. Despite comprehensive studies addressing PAs, a unifying concept to interpret their molecular role is missing. The precise biochemical function of polyamines is thus one of the remaining mysteries of molecular cell biology.

  7. Folic acid: nutritional biochemistry, molecular biology, and role in disease processes.

    Science.gov (United States)

    Lucock, M

    2000-01-01

    This paper reviews the chemistry, metabolism, and molecular biology of folic acid, with a particular emphasis on how it is, or may be, involved in many disease processes. Folic acid prevents neural tube defects like spina bifida, while its ability to lower homocysteine suggests it might have a positive influence on cardiovascular disease. A role for this B vitamin in maintaining good health may, in fact, extend beyond these clinical conditions to encompass other birth defects, several types of cancer, dementia, affective disorders, Down's syndrome, and serious conditions affecting pregnancy outcome. The effect of folate in these conditions can be explained largely within the context of folate-dependent pathways leading to methionine and nucleotide biosynthesis, and genetic variability resulting from a number of common polymorphisms of folate-dependent enzymes involved in the homocysteine remethylation cycle. Allelic variants of folate genes that have a high frequency in the population, and that may play a role in disease formation include 677C --> T-MTHFR, 1298A --> C-MTHFR, 2756A --> G-MetSyn, and 66A --> G-MSR. Future work will probably uncover further polymorphisms of folate metabolism, and lead to a wider understanding of the interaction between this essential nutrient and the many genes which underpin its enzymatic utilization in a plethora of critical biosynthetic reactions, and which, under adverse nutritional conditions, may promote disease.

  8. Mechanistic pathways and biological roles for receptor-independent activators of G-protein signaling.

    Science.gov (United States)

    Blumer, Joe B; Smrcka, Alan V; Lanier, Stephen M

    2007-03-01

    Signal processing via heterotrimeric G-proteins in response to cell surface receptors is a central and much investigated aspect of how cells integrate cellular stimuli to produce coordinated biological responses. The system is a target of numerous therapeutic agents and plays an important role in adaptive processes of organs; aberrant processing of signals through these transducing systems is a component of various disease states. In addition to G-protein coupled receptor (GPCR)-mediated activation of G-protein signaling, nature has evolved creative ways to manipulate and utilize the Galphabetagamma heterotrimer or Galpha and Gbetagamma subunits independent of the cell surface receptor stimuli. In such situations, the G-protein subunits (Galpha and Gbetagamma) may actually be complexed with alternative binding partners independent of the typical heterotrimeric Galphabetagamma. Such regulatory accessory proteins include the family of regulator of G-protein signaling (RGS) proteins that accelerate the GTPase activity of Galpha and various entities that influence nucleotide binding properties and/or subunit interaction. The latter group of proteins includes receptor-independent activators of G-protein signaling (AGS) proteins that play surprising roles in signal processing. This review provides an overview of our current knowledge regarding AGS proteins. AGS proteins are indicative of a growing number of accessory proteins that influence signal propagation, facilitate cross talk between various types of signaling pathways, and provide a platform for diverse functions of both the heterotrimeric Galphabetagamma and the individual Galpha and Gbetagamma subunits.

  9. Role of the C8 gem-dimethyl group of bryostatin 1 on its unique pattern of biological activity.

    Science.gov (United States)

    Keck, Gary E; Poudel, Yam B; Rudra, Arnab; Stephens, Jeffrey C; Kedei, Noemi; Lewin, Nancy E; Blumberg, Peter M

    2012-06-15

    The role of the C(8) gem-dimethyl group in the A-ring of bryostatin 1 has been examined through chemical synthesis and biological evaluation of a new analogue. Assays for biological function using U937, K562, and MV4-11 cells as well as the profiles for downregulation of PKC isozymes revealed that the presence of this group is not a critical determinant for the unique pattern of biological activity of bryostatin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    Science.gov (United States)

    Graves, David B.

    2012-07-01

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well.

  11. The role of biology in planetary evolution: cyanobacterial primary production in low‐oxygen Proterozoic oceans

    Science.gov (United States)

    Bryant, Donald A.; Macalady, Jennifer L.

    2016-01-01

    Summary Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well‐preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane‐derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O 2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co‐occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low‐oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic

  12. The role of biology in planetary evolution: cyanobacterial primary production in low-oxygen Proterozoic oceans.

    Science.gov (United States)

    Hamilton, Trinity L; Bryant, Donald A; Macalady, Jennifer L

    2016-02-01

    Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane-derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co-occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low-oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic photosynthesis

  13. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification.

    Science.gov (United States)

    De Maayer, Pieter; Chan, Wai-Yin; Blom, Jochen; Venter, Stephanus N; Duffy, Brion; Smits, Theo H M; Coutinho, Teresa A

    2012-11-15

    Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of a large plasmid common to all sequenced Pantoea spp. The Large PantoeaPlasmids (LPP-1) of twenty strains encompassing seven different Pantoea species, including pathogens and endo-/epiphytes of a wide range of plant hosts as well as insect-associated strains, were compared. The LPP-1 plasmid sequences range in size from ~281 to 794 kb and carry between 238 and 750 protein coding sequences (CDS). A core set of 46 proteins, encompassing 2.2% of the total pan-plasmid (2,095 CDS), conserved among all LPP-1 plasmid sequences, includes those required for thiamine and pigment biosynthesis. Phylogenetic analysis reveals that these plasmids have arisen from an ancestral plasmid, which has undergone extensive diversification. Analysis of the proteins encoded on LPP-1 also showed that these plasmids contribute to a wide range of Pantoea phenotypes, including the transport and catabolism of various substrates, inorganic ion assimilation, resistance to antibiotics and heavy metals, colonization and persistence in the host and environment, pathogenesis and antibiosis. LPP-1 is universal to all Pantoea spp. whose genomes have been sequenced to date and is derived from an ancestral plasmid. LPP-1 encodes a large array of proteins that have played a major role in the adaptation of the different Pantoea spp. to their various ecological niches and their specialization as pathogens, biocontrol agents or benign saprophytes found in many diverse environments.

  14. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

    Directory of Open Access Journals (Sweden)

    De Maayer Pieter

    2012-11-01

    Full Text Available Abstract Background Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of a large plasmid common to all sequenced Pantoea spp. Results and discussion The Large PantoeaPlasmids (LPP-1 of twenty strains encompassing seven different Pantoea species, including pathogens and endo-/epiphytes of a wide range of plant hosts as well as insect-associated strains, were compared. The LPP-1 plasmid sequences range in size from ~281 to 794 kb and carry between 238 and 750 protein coding sequences (CDS. A core set of 46 proteins, encompassing 2.2% of the total pan-plasmid (2,095 CDS, conserved among all LPP-1 plasmid sequences, includes those required for thiamine and pigment biosynthesis. Phylogenetic analysis reveals that these plasmids have arisen from an ancestral plasmid, which has undergone extensive diversification. Analysis of the proteins encoded on LPP-1 also showed that these plasmids contribute to a wide range of Pantoea phenotypes, including the transport and catabolism of various substrates, inorganic ion assimilation, resistance to antibiotics and heavy metals, colonization and persistence in the host and environment, pathogenesis and antibiosis. Conclusions LPP-1 is universal to all Pantoea spp. whose genomes have been sequenced to date and is derived from an ancestral plasmid. LPP-1 encodes a large array of proteins that have played a major role in the adaptation of the different Pantoea spp. to their various ecological niches and their specialization as pathogens, biocontrol agents or benign saprophytes found in many diverse

  15. Biological stress regulation in female adolescents: a key role for confiding.

    Science.gov (United States)

    Oskis, Andrea; Clow, Angela; Loveday, Catherine; Hucklebridge, Frank; Sbarra, David A

    2015-05-01

    Attachment behaviors play a critical role in regulating emotion within the context of close relationships, and attachment theory is currently used to inform evidence-based practice in the areas of adolescent health and social care. This study investigated the association between female adolescents' interview-based attachment behaviors and two markers of hypothalamic-pituitary-adrenal axis activity: cortisol and dehydroepiandrosterone (DHEA). Unlike the classic stress hormone cortisol, there is very limited investigation of DHEA-a quintessential developmental hormone-in relation to attachment, especially in adolescents. Fifty-five healthy females mean age 14.36 (±2.41) years participated in the attachment style interview. A smaller cortisol awakening response was related to anxious attachment attitudes, including more fear of rejection, whereas greater morning basal DHEA secretion was only predicted by lower levels of reported confiding in one's mother. These attachment-hormone relationships may be developmental markers in females, as they were independent of menarche status. These findings highlight that the normative shifts occurring in attachment to caregivers around adolescence are reflected in adolescents' biological stress regulation. We discuss how studying these shifts can be informed by evolutionary-developmental theory.

  16. Therapeutic potential and biological role of endogenous antioxidant enzymes in multiple sclerosis pathology.

    Science.gov (United States)

    Schreibelt, Gerty; van Horssen, Jack; van Rossum, Saskia; Dijkstra, Christine D; Drukarch, Benjamin; de Vries, Helga E

    2007-12-01

    Reactive oxygen species contribute to the formation and persistence of multiple sclerosis (MS) lesions by acting on distinct pathological processes. To counteract the detrimental effects of ROS the central nervous system is endowed with a protective mechanism consisting of enzymatic and non-enzymatic antioxidants. Expression of most antioxidant enzymes is regulated through the transcription factor nuclear factor-E2-related factor (Nrf2) and antioxidant response elements (ARE) in the genes encoding enzymatic antioxidants and is induced by oxidative stress. In brain tissue of MS patients, enhanced expression of Nrf2/ARE-regulated antioxidants is suggestive of the occurrence of oxidative stress in these lesions. Antioxidant therapy may therefore represent an attractive treatment of MS. Several studies have shown that antioxidant therapy is beneficial in vitro and in vivo in animal models for MS. However, the use of exogenous antioxidants for MS treatment has drawbacks, as large amounts of antioxidants are required to achieve functional antioxidant levels in the central nervous system. Therefore, the induction of endogenous antioxidant enzymes by activators of the Nrf2/ARE pathway may be an interesting approach to obtain sufficient levels of antioxidants to interfere with pathological processes underlying MS lesion formation. In this review we summarize and discuss the biological role, regulation and potential therapeutic effects of endogenous antioxidant enzymes in MS. We propose that antioxidants may inhibit the development and progression of MS lesions and may therefore represent an attractive therapeutic target for the treatment of MS and other oxidative stress-related neurological diseases.

  17. Role of neutrophils in innate immunity: a systems biology-level approach.

    Science.gov (United States)

    Kobayashi, Scott D; DeLeo, Frank R

    2009-01-01

    The innate immune system is the first line of host defense against invading microorganisms. Polymorphonuclear leukocytes (PMNs or neutrophils) are the most abundant leukocyte in humans and essential to the innate immune response against invading pathogens. Compared with the acquired immune response, which requires time to develop and is dependent on previous interaction with specific microbes, the ability of neutrophils to kill microorganisms is immediate, non-specific, and not dependent on previous exposure to microorganisms. Historically, studies on PMN-pathogen interaction focused on the events leading to killing of microorganisms, such as recruitment/chemotaxis, transmigration, phagocytosis, and activation, whereas post-phagocytosis sequelae were infrequently considered. In addition, it was widely accepted that human neutrophils possessed limited capacity for new gene transcription and thus, relatively little biosynthetic capacity. This notion has changed dramatically within the past decade. Further, there is now more effort directed to understand the events occurring in PMNs after killing of microbes. Herein we review the systems biology-level approaches that have been used to gain an enhanced view of the role of neutrophils during host-pathogen interaction. We anticipate that these and future systems-level studies will ultimately provide information critical to our understanding, treatment, and control of diseases caused by pathogenic microorganisms.

  18. Possible roles of phospholipase A(2) in the biological activities of Acanthamoeba castellanii (T4 Genotype).

    Science.gov (United States)

    Mortazavi, Parisa Nakhostin; Keisary, Ehud; Loh, Lip Nam; Jung, Suk-Yul; Khan, Naveed Ahmed

    2011-01-01

    Using phospholipases A(2)-specific spectrophotometric assays, it was shown thatA. castellaniilysates and their conditioned medium exhibit phospholipase activities. The extracellular levels of PLA(2)detected were significantly reduced compared with the cell-associated enzyme (P<0.05). Sphinganine, a PLA(2)inhibitor showed robust amoebistatic properties but had no effect on the viability ofA. castellanii. The potency of sphinganine was demonstrated effectively towards purified PLA(2)derived from porcine pancreas. Using sphinganine, it was observed that PLA(2)is involved in neither binding nor cytotoxicity of the human brain microvascular endothelial cells due toA. castellanii. Unlike as was the case forDictyosteliumamoebae, PLA(2)appeared to be involved inA. castellaniiphagocytosis of the fluorescently-labelled polystyrene beads. Horseradish peroxidase was used as a tracer molecule to develop assays to study pinocytosis inA. castellanii. The findings revealed that sphinganine impedes phagocytosis but augments pinocytosis inA. castellaniisuggesting distinct nature of processes. A complete understanding of the role of phospholipases in the biology and pathogenesis ofA. castellaniiinfections will determine their potential as therapeutic targets.

  19. Biological effects of IL-21 on different immune cells and its role in autoimmune diseases.

    Science.gov (United States)

    Gharibi, Tohid; Majidi, Jafar; Kazemi, Tohid; Dehghanzadeh, Rashedeh; Motallebnezhad, Morteza; Babaloo, Zohreh

    2016-02-01

    Interleukin-21 (IL-21) is a member of the common γ-chain cytokines with broad pleiotropic actions that affects different immune and nonimmune cells. IL-21 can affect differentiation, proliferation and function of T and B cells; it can also induce the maturation and enhance the cytotoxicity of CD8+ T cells and Natural killer (NK) cells. IL-21 exerts major effects on B-cell activation and differentiation or apoptosis during humoral immune responses and induces differentiation of naïve B cells and memory B cells into plasma cells. IL-21 also affects different subtypes of T cells including T helper-17 (TH17), T follicular helper (TFH) and regulatory T (Treg) cells and thereby promotes the development of autoimmune disorders and inflammatory diseases. Observations have shown that the blockade of IL-21 has therapeutic effects on various autoimmune diseases in animal models. A better understanding of the regulation of cell differentiation and stabilization by IL-21 in the context of each specific autoimmune disease or tissue-specific pathological microenvironments will be helpful in developing novel treatments to control autoimmune diseases. Herein, we review the biological effects of IL-21 on different immune cells and uncover the emerging role of this interesting cytokine in autoimmune diseases.

  20. Role of L-arginine in the biological effects of blue light

    Science.gov (United States)

    Makela, Anu M.

    2005-11-01

    Arginine, a semi-essential amino acid, and metabolites of arginine exert multiple biological effects. It has been known that arginine causes the release of various hormones such as insulin, glucagon, growth hormone, prolactin, and adrenal catecholamines. Arginine infusion also produces vasodilation, and in the kidney increased plasma flow accompanied by increases in glomerular filtration rate (GFR). Recent studies have showed that blue and red light irradiation in vitro and in vivo can increase production of nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS). These then can modulate the production and secretion of several cytokines and other mediators and play an important role as regulatory mediators in signaling processes which can then modulate the production, mobilization and homing of stem cells. It is proposed that some of the therapeutic effects of light can be considered to be due to the changes in the metabolism of L-arginine. The regulation of L-arginine turnover by the use of light at blue wavelengths between 400nm and 510nm can be the explanation for some of the observed effects of blue light: lowering of blood pressure, pain killing effect, regulating insulin production, anti-inflammatory action, and possible effects on the release and homing of stem cells.

  1. Role of cell-cell adhesion complexes in embryonic stem cell biology.

    Science.gov (United States)

    Pieters, Tim; van Roy, Frans

    2014-06-15

    Pluripotent embryonic stem cells (ESCs) can self-renew or differentiate into any cell type within an organism. Here, we focus on the roles of cadherins and catenins - their cytoplasmic scaffold proteins - in the fate, maintenance and differentiation of mammalian ESCs. E-cadherin is a master stem cell regulator that is required for both mouse ESC (mESC) maintenance and differentiation. E-cadherin interacts with key components of the naive stemness pathway and ablating it prevents stem cells from forming well-differentiated teratomas or contributing to chimeric animals. In addition, depleting E-cadherin converts naive mouse ESCs into primed epiblast-like stem cells (EpiSCs). In line with this, a mesenchymal-to-epithelial transition (MET) occurs during reprogramming of somatic cells towards induced pluripotent stem cells (iPSCs), leading to downregulation of N-cadherin and acquisition of high E-cadherin levels. β-catenin exerts a dual function; it acts in cadherin-based adhesion and in WNT signaling and, although WNT signaling is important for stemness, the adhesive function of β-catenin might be crucial for maintaining the naive state of stem cells. In addition, evidence is rising that other junctional proteins are also important in ESC biology. Thus, precisely regulated levels and activities of several junctional proteins, in particular E-cadherin, safeguard naive pluripotency and are a prerequisite for complete somatic cell reprogramming.

  2. Biological role of surface Toxoplasma gondii antigen in development of vaccine

    Institute of Scientific and Technical Information of China (English)

    Ke-Yi Liu; Dian-Bo Zhang; Qing-Kuan Wei; Jin Li; Gui-Ping Li; Jin-Zhi Yu

    2006-01-01

    AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii (T gondii) in development of vaccine.METHODS: The surface antigen of Tgondii (SAG1)was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1and challenged with lethal strain of T gondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on T gondii tachyzoites under electromicroscope.RESULTS:The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group.The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-γ, IL-2 and IL-4cytokines in mice. In contrast, IL-12, IL-6 and TNF-αwere undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed,swollen, and holes and gaps formed on the surface.CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.

  3. Allosteric role of the large-scale domain opening in biological catch-binding

    Science.gov (United States)

    Pereverzev, Yuriy V.; Prezhdo, Oleg V.; Sokurenko, Evgeni V.

    2009-05-01

    The proposed model demonstrates the allosteric role of the two-domain region of the receptor protein in the increased lifetimes of biological receptor/ligand bonds subjected to an external force. The interaction between the domains is represented by a bounded potential, containing two minima corresponding to the attached and separated conformations of the two protein domains. The dissociative potential with a single minimum describing receptor/ligand binding fluctuates between deep and shallow states, depending on whether the domains are attached or separated. A number of valuable analytic expressions are derived and are used to interpret experimental data for two catch bonds. The P-selectin/P-selectin-glycoprotein-ligand-1 (PSGL-1) bond is controlled by the interface between the epidermal growth factor (EGF) and lectin domains of P-selectin, and the type 1 fimbrial adhesive protein (FimH)/mannose bond is governed by the interface between the lectin and pilin domains of FimH. Catch-binding occurs in these systems when the external force stretches the receptor proteins and increases the interdomain distance. The allosteric effect is supported by independent measurements, in which the domains are kept separated by attachment of another ligand. The proposed model accurately describes the experimentally observed anomalous behavior of the lifetimes of the P-selectin/PSGL-1 and FimH/mannose complexes as a function of applied force and provides valuable insights into the mechanism of catch-binding.

  4. Cryptococcus neoformans dual GDP-mannose transporters and their role in biology and virulence.

    Science.gov (United States)

    Wang, Zhuo A; Griffith, Cara L; Skowyra, Michael L; Salinas, Nichole; Williams, Matthew; Maier, Ezekiel J; Gish, Stacey R; Liu, Hong; Brent, Michael R; Doering, Tamara L

    2014-06-01

    Cryptococcus neoformans is an opportunistic yeast responsible for lethal meningoencephalitis in humans. This pathogen elaborates a polysaccharide capsule, which is its major virulence factor. Mannose constitutes over one-half of the capsule mass and is also extensively utilized in cell wall synthesis and in glycosylation of proteins and lipids. The activated mannose donor for most biosynthetic reactions, GDP-mannose, is made in the cytosol, although it is primarily consumed in secretory organelles. This compartmentalization necessitates specific transmembrane transporters to make the donor available for glycan synthesis. We previously identified two cryptococcal GDP-mannose transporters, Gmt1 and Gmt2. Biochemical studies of each protein expressed in Saccharomyces cerevisiae showed that both are functional, with similar kinetics and substrate specificities in vitro. We have now examined these proteins in vivo and demonstrate that cells lacking Gmt1 show significant phenotypic differences from those lacking Gmt2 in terms of growth, colony morphology, protein glycosylation, and capsule phenotypes. Some of these observations may be explained by differential expression of the two genes, but others suggest that the two proteins play overlapping but nonidentical roles in cryptococcal biology. Furthermore, gmt1 gmt2 double mutant cells, which are unexpectedly viable, exhibit severe defects in capsule synthesis and protein glycosylation and are avirulent in mouse models of cryptococcosis.

  5. Insights into the key roles of proteoglycans in breast cancer biology and translational medicine.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Neill, Thomas; Multhaupt, Hinke A B; Hubo, Mario; Frey, Helena; Gopal, Sandeep; Gomes, Angélica; Afratis, Nikos; Lim, Hooi Ching; Couchman, John R; Filmus, Jorge; Sanderson, Ralph D; Schaefer, Liliana; Iozzo, Renato V; Karamanos, Nikos K

    2015-04-01

    Proteoglycans control numerous normal and pathological processes, among which are morphogenesis, tissue repair, inflammation, vascularization and cancer metastasis. During tumor development and growth, proteoglycan expression is markedly modified in the tumor microenvironment. Altered expression of proteoglycans on tumor and stromal cell membranes affects cancer cell signaling, growth and survival, cell adhesion, migration and angiogenesis. Despite the high complexity and heterogeneity of breast cancer, the rapid evolution in our knowledge that proteoglycans are among the key players in the breast tumor microenvironment suggests their potential as pharmacological targets in this type of cancer. It has been recently suggested that pharmacological treatment may target proteoglycan metabolism, their utilization as targets for immunotherapy or their direct use as therapeutic agents. The diversity inherent in the proteoglycans that will be presented herein provides the potential for multiple layers of regulation of breast tumor behavior. This review summarizes recent developments concerning the biology of selected proteoglycans in breast cancer, and presents potential targeted therapeutic approaches based on their novel key roles in breast cancer.

  6. Signal amplification in biological and electrical engineering systems: universal role of cascades.

    Science.gov (United States)

    Grubelnik, Vladimir; Dugonik, Bogdan; Osebik, Davorin; Marhl, Marko

    2009-08-01

    In this paper we compare the cascade mechanisms of signal amplification in biological and electrical engineering systems, and show that they share the capacity to considerably amplify signals, and respond to signal changes both quickly and completely, which effectively preserves the form of the input signal. For biological systems, these characteristics are crucial for efficient and reliable cellular signaling. We show that this highly-efficient biological mechanism of signal amplification that has naturally evolved is mathematically fully equivalent with some man-developed amplifiers, which indicates parallels between biological evolution and successful technology development.

  7. Role of miRNAs in muscle stem cell biology: proliferation, differentiation and death.

    Science.gov (United States)

    Crippa, Stefania; Cassano, Marco; Sampaolesi, Maurilio

    2012-01-01

    miRNAs are small non-coding RNAs that regulate post-transcriptionally gene expression by degradation or translational repression of specific target mRNAs. In the 90s, lin-4 and let-7 were firstly identified as small regulatory RNAs able to control C. elegans larval development, by specifically targeting the 3'UTR of lin-14 and lin-28, respectively. These findings have introduced a novel and wide layer of complexity in the regulation of mRNA and protein expression. Lin-4 and let-7 are now considered the founding members of an abundant class of small fine-tuned RNAs, called microRNAs (miRNAs), in viruses, green algae, plants, flies, worms, and in mammals. In humans, the estimated number of genes encoding for miRNAs is as high as 1000 and around 30% of the protein-coding genes are post-transcriptionally controlled by miRNAs. This article reviews the role of miRNAs in regulating several biological responses in muscle cells, ranging from proliferation, differentiation and adaptation to stress cues. Cardiac and skeletal muscles are powerful examples to summarize the activity of miRNAs in cell fate specification, lineage differentiation and metabolic pathways. Indeed, specific miRNAs control the number of proliferating muscle progenitors to guarantee the proper formation of the heart and muscle fibers and to assure the self-renewal of muscle progenitors during adult tissue regeneration. On the other side, several other miRNAs promote the differentiation of muscle progenitors into skeletal myofibers or into cardiomyocytes, where metabolic activity, survival and remodeling process in response to stress, injury and chronic diseases are also fine-tuned by miRNAs.

  8. The silica cycle in a Northeast Pacific fjord; the role of biological resuspension

    Science.gov (United States)

    Katz, Timor; Yahel, Gitai; Tunnicliffe, Verena; Herut, Barak; Whitney, Frank; Snelgrove, Paul V. R.; Lazar, Boaz

    2016-09-01

    This study is a quantitative assessment of the role fish-induced bio-resuspension plays in the silica cycle of coastal waters. We used new, published and archived oceanographic data to construct a comprehensive silica budget for Saanich Inlet (Vancouver Island, Canada), a highly productive Northeast Pacific fjord, where siliceous diatoms dominate primary productivity. Anoxia in the deep water of the inlet persists during most of the year, precluding animal life, whereas abundant groundfish continuously rework and resuspend bottom sediments in the shallower, oxygenated margins. This resuspension transfers settled biogenic silica fragments from the sediment, where they are immersed in porewater that is rich with dissolved silica, to the overlying water, where the much lower concentrations accelerate their dissolution rate. The budget shows that Saanich Inlet sediments constitute a sink for approximately 250 × 106 mol Si y-1. Most of this Si enters the inlet in advected, siliceous phytoplankton. Sediment resuspension by groundfish in the oxygenated margins of Saanich Inlet generates about 50% of the total flux of dissolved silica from the inlet seafloor. This resuspension also facilitates a massive transport of biogenic silica from the margins to the anoxic basin, where approximately 90% of all the biogenic silica is buried. The excess dissolution caused by fish activity reduces the burial efficiency of biogenic silica in the entire inlet sediments by about 20%. This case study emphasizes the link between the silica cycle and groundfish activity. Based on this study and because biological resuspension occurs in most regions of the ocean, we recommend that it will be taken into account when budgeting the silica cycle, and potentially other geochemical cycles, in marine environments.

  9. The role of Src kinase in the biology and pathogenesis of Acanthamoeba castellanii

    Directory of Open Access Journals (Sweden)

    Siddiqui Ruqaiyyah

    2012-06-01

    Full Text Available Abstract Background Acanthamoeba species are the causative agents of fatal granulomatous encephalitis in humans. Haematogenous spread is thought to be a primary step, followed by blood–brain barrier penetration, in the transmission of Acanthmaoeba into the central nervous system, but the associated molecular mechanisms remain unclear. Here, we evaluated the role of Src, a non-receptor protein tyrosine kinase in the biology and pathogenesis of Acanthamoeba. Methods Amoebistatic and amoebicidal assays were performed by incubating amoeba in the presence of Src kinase-selective inhibitor, PP2 (4-amino-5-(4-chlorophenyl-7-(t-butylpyrazolo[3,4-d]pyrimidine and its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d]pyrimidine. Using this inhibitor, the role of Src kinase in A. castellanii interactions with Escherichia coli was determined. Zymographic assays were performed to study effects of Src kinase on extracellular proteolytic activities of A. castellanii. The human brain microvascular endothelial cells were used to determine the effects of Src kinase on A. castellanii adhesion to and cytotoxicity of host cells. Results Inhibition of Src kinase using a specific inhibitor, PP2 (4-amino-5-(4 chlorophenyl-7-(t-butylpyrazolo [3,4-d] pyrimidine but not its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d] pyrimidine, had detrimental effects on the growth of A. castellanii (keratitis isolate, belonging to the T4 genotype. Interestingly, inhibition of Src kinase hampered the phagocytic ability of A. castellanii, as measured by the uptake of non-invasive bacteria, but, on the contrary, invasion by pathogenic bacteria was enhanced. Zymographic assays revealed that inhibition of Src kinases reduced extracellular protease activities of A. castellanii. Src kinase inhibition had no significant effect on A. castellanii binding to and cytotoxicity of primary human brain microvascular endothelial cells, which constitute the blood–brain barrier

  10. Parenting Practices of Resident Fathers: The Role of Marital and Biological Ties

    Science.gov (United States)

    Berger, Lawrence M.; Carlson, Marcia J.; Bzostek, Sharon H.; Osborne, Cynthia

    2008-01-01

    This paper uses data from the Fragile Families and Child Wellbeing Study (N = 2,098) to examine differences in the parenting practices of four types of resident fathers, defined by their biological relationship to a focal child and their marital status with regard to the focal child's mother. Regression results suggest that biological fathers and…

  11. The chemical biology of hydropersulfides (RSSH): Chemical stability, reactivity and redox roles.

    Science.gov (United States)

    Saund, Simran S; Sosa, Victor; Henriquez, Stephanie; Nguyen, Q Nhu N; Bianco, Christopher L; Soeda, Shuhei; Millikin, Robert; White, Corey; Le, Henry; Ono, Katsuhiko; Tantillo, Dean J; Kumagai, Yoshito; Akaike, Takaaki; Lin, Joseph; Fukuto, Jon M

    2015-12-15

    Recent reports indicate the ubiquitous prevalence of hydropersulfides (RSSH) in mammalian systems. The biological utility of these and related species is currently a matter of significant speculation. The function, lifetime and fate of hydropersulfides will be assuredly based on their chemical properties and reactivity. Thus, to serve as the basis for further mechanistic studies regarding hydropersulfide biology, some of the basic chemical properties/reactivity of hydropersulfides was studied. The nucleophilicity, electrophilicity and redox properties of hydropersulfides were examined under biological conditions. These studies indicate that hydropersulfides can be nucleophilic or electrophilic, depending on the pH (i.e. the protonation state) and can act as good one- and two-electron reductants. These diverse chemical properties in a single species make hydropersulfides chemically distinct from other, well-known sulfur containing biological species, giving them unique and potentially important biological function. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. The role of Ikaros transcriptional factor in normal hematopoiesis and leukemogenesis: biological and clinical aspects

    Directory of Open Access Journals (Sweden)

    V. S. Vshivkoo

    2015-01-01

    , are the most significant features. These mutations of IKZF1 gene and Ikaros aberrant expression play a key role in the lymphoid transformation, tumor progression, and may cause development of leukemic cells chemoresistance. Therefore, IKZF1 aberrations should be taken into account as a valuable prognostic marker for risk groups stratification, poor outcome and low survival rare. This review compiles currently available data regarding the frequency and variants of the IKZF1 (Ikaros aberrations, and the use of them in diagnostics of all types of leukemia and minimal residual disease detection. Although Ikaros has already applied in clinical studies, a growing number of questions  still remain unanswered. Molecular biology of IKZF1 expression and splicing regulation is not well understood. Clinical value of point mutations and subclonal deletion in IKZF1 locus should be elucidated. Prognostic significance of intragenic deletions and aberrant splicing is necessary to clarify for different groups of ALL patients, in connection with other genetic markers and therapy protocol. More detailed clinical analysis required for proving IKZF1 impact on probability of relapse, improving patients, risk stratification and application of minimal residual disease.

  13. BIOLOGICAL SEX, SEX-ROLE ORIENTATION, MASCULINE SEX-ROLE STRESS, DISSIMULATION AND SELF-REPORTED FEARS

    NARCIS (Netherlands)

    ARRINDELL, WA; KOLK, AM; PICKERSGILL, MJ; HAGEMAN, WJJM

    1993-01-01

    Given meta-analytic findings showing females to be generally more fearful than males on multi-dimensional self-report measures of fear, an empirical attempt was made to examine whether this outcome could be explained by psychological factors such as sex role orientation and masculine sex role stress

  14. BIOLOGICAL SEX, SEX-ROLE ORIENTATION, MASCULINE SEX-ROLE STRESS, DISSIMULATION AND SELF-REPORTED FEARS

    NARCIS (Netherlands)

    ARRINDELL, WA; KOLK, AM; PICKERSGILL, MJ; HAGEMAN, WJJM

    1993-01-01

    Given meta-analytic findings showing females to be generally more fearful than males on multi-dimensional self-report measures of fear, an empirical attempt was made to examine whether this outcome could be explained by psychological factors such as sex role orientation and masculine sex role

  15. The role of mechanics in biological and bio-inspired systems.

    Science.gov (United States)

    Egan, Paul; Sinko, Robert; LeDuc, Philip R; Keten, Sinan

    2015-07-06

    Natural systems frequently exploit intricate multiscale and multiphasic structures to achieve functionalities beyond those of man-made systems. Although understanding the chemical make-up of these systems is essential, the passive and active mechanics within biological systems are crucial when considering the many natural systems that achieve advanced properties, such as high strength-to-weight ratios and stimuli-responsive adaptability. Discovering how and why biological systems attain these desirable mechanical functionalities often reveals principles that inform new synthetic designs based on biological systems. Such approaches have traditionally found success in medical applications, and are now informing breakthroughs in diverse frontiers of science and engineering.

  16. Inhibitors of dihydroceramide desaturase 1: Therapeutic agents and pharmacological tools to decipher the role of dihydroceramides in cell biology.

    Science.gov (United States)

    Casasampere, Mireia; Ordoñez, Yadira F; Pou, Ana; Casas, Josefina

    2016-05-01

    Dihydroceramide desaturase (Des1) is the last enzyme in the de novo synthesis of ceramides (Cer). It catalyzes the insertion of a double bond into dihydroceramides (dhCer) to convert them to Cer, both of which are further metabolized to more complex (dihydro) sphingolipids. For many years dhCer have received poor attention, mainly due to their supposed lack of biological activity. It was not until about ten years ago that the concept that dhCer might have regulatory roles in biology emerged for the first time. Since then, multiple publications have established that dhCer are implicated in a wide spectrum of biological processes. Physiological and pathophysiological functions of dhCer have been recently reviewed. In this review we will focus on the biochemical features of Des1 and on its inhibition by different compounds with presumably different modes of action.

  17. Functional profiles reveal unique ecological roles of various biological soil crust organisms

    Science.gov (United States)

    Bowker, M.A.; Mau, R.L.; Maestre, F.T.; Escolar, C.; Castillo-Monroy, A. P.

    2011-01-01

    1. At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi-function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact play unique roles in ecosystems. 2. Over the last few decades, the significance of biological soil crusts (BSCs) as ecological boundaries and ecosystem engineers, and their multi-functional nature, has become increasingly well documented. We compiled 'functional profiles' of the organisms in this understudied community, to determine whether functional singularity emerges when multiple ecosystem functions are considered. 3. In two data sets, one representing multiple sites around the semi-arid regions of Spain (regional scale), and another from a single site in central Spain (local scale), we examined correlations between the abundance or frequency of BSC species in a community, and multiple surrogates of ecosystem functioning. There was a wide array of apparent effects of species on specific functions. 4. Notably, in gypsiferous soils and at regional scale, we found that indicators of carbon (C) and phosphorus cycling were apparently suppressed and promoted by the lichens Diploschistes diacapsis and Squamarina lentigera, respectively. The moss Pleurochaete squarrosa appears to promote C cycling in calcareous soils at this spatial scale. At the local scale in gypsiferous soils, D. diacapsis positively correlated with carbon cycling, but negatively with nitrogen cycling, whereas numerous lichens exhibited the opposite profile. 5. We found a high degree of functional singularity, i.e. that species were highly individualistic in their effects on multiple functions. Many functional attributes were not easily predictable from existing functional grouping systems based primarily on morphology. 6. Our results suggest that maintaining

  18. On Beyond Star Trek, the Role of Synthetic Biology in Nasa's Missions

    Science.gov (United States)

    Rothschild, Lynn J.

    2016-01-01

    The time has come to for NASA to exploit the nascent field of synthetic biology in pursuit of its mission, including aeronautics, earth science, astrobiology and notably, human exploration. Conversely, NASA advances the fundamental technology of synthetic biology as no one else can because of its unique expertise in the origin of life and life in extreme environments, including the potential for alternate life forms. This enables unique, creative "game changing" advances. NASA's requirement for minimizing upmass in flight will also drive the field toward miniaturization and automation. These drivers will greatly increase the utility of synthetic biology solutions for military, health in remote areas and commercial purposes. To this end, we have begun a program at NASA to explore the use of synthetic biology in NASA's missions, particularly space exploration. As part of this program, we began hosting an iGEM team of undergraduates drawn from Brown and Stanford Universities to conduct synthetic biology research at NASA Ames Research Center. The 2011 team (http://2011.igem.org/Team:Brown-Stanford) produced an award-winning project on using synthetic biology as a basis for a human Mars settlement and the 2012 team has expanded the use of synthetic biology to estimate the potential for life in the clouds of other planets (http://2012.igem.org/Team:Stanford-Brown; http://www.calacademy.org/sciencetoday/igem-competition/). More recent projects from the Stanford-Brown team have expanded our ideas of how synthetic biology can aid NASA's missions from "Synthetic BioCommunication" (http://2013.igem.org/Team:Stanford-Brown) to a "Biodegradable UAS (drone)" in collaboration with Spelman College (http://2014.igem.org/Team:StanfordBrownSpelman#SBS%20iGEM) and most recently, "Self-Folding Origami" (http://2015.igem.org/Team:Stanford-Brown), the winner of the 2015 award for Manufacturing.

  19. Role of Moving Bed Biofilm Reactor and Sequencing Batch Reactor in Biological Degradation of Formaldehyde Wastewater

    OpenAIRE

    2011-01-01

    Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR) and sequencing batch reactors (SBR) were investigated. During all experiments, the efficiency of SBR ...

  20. Autotaxin: Its Role in Biology of Melanoma Cells and as a Pharmacological Target

    Directory of Open Access Journals (Sweden)

    Maciej Jankowski

    2011-01-01

    Full Text Available Autotaxin (ATX is an extracellular lysophospholipase D (lysoPLD released from normal cells and cancer cells. Activity of ATX is detected in various biological fluids. The lysophosphatidic acid (LPA is the main product of ATX. LPA acting through specific G protein-coupled receptors (LPA1-LPA6 affects immunological response, normal development, and malignant tumors' formation and progression. In this review, the impact of autotoxin on biology of melanoma cells and potential treatment is discussed.

  1. BIOLOGICAL ROLE AND TOXIC INFLUENCE OF MOLYBDENUM IN AQUATIC ECOSYSTEMS (A REVIEW

    Directory of Open Access Journals (Sweden)

    І. Hrytsyniak

    2016-09-01

    Full Text Available Purpose. The consequence of human impact of the ecosystems of water bodies are as a rule the input of xenobiotics of various natures or the excess of the natural level of biogenic trace elements that ultimately leads to negative changes in the structure of aquatic biota communities, disturbances of vital activity processes of some flora and fauna species. The consequences of these processes are presented as a reduction in the productivity of water bodies, impoverishment of their species variety, and subsequently as an unsuitability of water bodies for fisheries related activities. Study, analysis and generalization of information concerning the pathways of toxicants input into water bodies, their behavior in hydroecosystems, possible effects on aquatic organisms of different trophic levels have an important theoretical and practical value. Behavioral, physiological, biochemical, cytological, histological and genetic reactions can serve as a basis for the adoption of necessary measures aimed at improving the ecological state of water bodies or preventing and avoiding potential hazards to aquatic populations. The aim of this work is an analysis and synthesis of the available literature data about the role of a relatively poorly studied trace element molybdenum in hydroecosystems, its biological importance and toxic effect for aquatic organisms. Findings. The data containing in the article were obtained based on reviewing existing publications of domestic and foreign authors. In particular, they describe hydrochemical properties of molybdenum and its compounds, possible sources of input into water bodies, pathways of element migration. A brief description of the identification and control methods for the element content in aquatic environment is presented. Biophilic properties of molybdenum for aquatic flora and fauna as well as the impact on their productive parameters are described. The data regarding the bioaccumulation potential of molybdenum

  2. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

    OpenAIRE

    De Maayer Pieter; Chan Wai-Yin; Blom Jochen; Venter Stephanus N; Duffy Brion; Smits Theo H M; Coutinho Teresa A

    2012-01-01

    Abstract Background Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of...

  3. Causes and consequences of failed adaptation to biological invasions: the role of ecological constraints.

    Science.gov (United States)

    Lau, Jennifer A; terHorst, Casey P

    2015-05-01

    Biological invasions are a major challenge to native communities and have the potential to exert strong selection on native populations. As a result, native taxa may adapt to the presence of invaders through increased competitive ability, increased antipredator defences or altered morphologies that may limit encounters with toxic prey. Yet, in some cases, species may fail to adapt to biological invasions. Many challenges to adaptation arise because biological invasions occur in complex species-rich communities in spatially and temporally variable environments. Here, we review these 'ecological' constraints on adaptation, focusing on the complications that arise from the need to simultaneously adapt to multiple biotic agents and from temporal and spatial variation in both selection and demography. Throughout, we illustrate cases where these constraints might be especially important in native populations faced with biological invasions. Our goal was to highlight additional complexities empiricists should consider when studying adaptation to biological invasions and to begin to identify conditions when adaptation may fail to be an effective response to invasion. © 2015 John Wiley & Sons Ltd.

  4. The role of evolutionary biology in research and control of liver flukes in Southeast Asia.

    Science.gov (United States)

    Echaubard, Pierre; Sripa, Banchob; Mallory, Frank F; Wilcox, Bruce A

    2016-09-01

    Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework.

  5. Role of basic biological sciences in clinical orthodontics: a case series.

    Science.gov (United States)

    Davidovitch, Ze'ev; Krishnan, Vinod

    2009-02-01

    Orthodontic therapy is based on interaction between mechanics and biology. Basic biologic research aims at developing a better understanding of the mechanism of transformation of mechanical energy into biologic reactions, and exposing the reasons for iatrogenic tissue damage in orthodontics. Previous research has shown that inflammation is a major part of the biologic response to orthodontic forces. In inflammation, signal molecules that originate in remote diseased organs can reach strained paradental tissues and exacerbate the inflammatory process, leading to tissue damage. Our case series includes 3 patients, each having had systemic diseases and malocclusion. One had diabetes mellitus, Hashimoto's thyroiditis, and depression. Concern about the possible effect of these conditions on the well-being of the teeth and their surrounding tissues compelled the orthodontist to choose not to treat this patient. The other 2 patients had allergies, and 1 also had bronchial asthma and bruises. Although these conditions are thought to be risk factors for root resorption, these patients received orthodontic treatment for 2 and 3.5 years, respectively. At the end of treatment, both had excessive root resorption of many teeth. In 1 patient, this damage led to the loss of most maxillary teeth. Basic research should continue to address questions related to the biologic mechanisms of tooth movement on tissue, cellular, and molecular levels. Moreover, this research should continue to identify risk factors that might jeopardize the longevity of treated teeth. Such basic research should promote the development of new tissue-friendly and patient-friendly therapeutic methods.

  6. A role for biological optimization within the current treatment planning paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2009-10-15

    Purpose: Biological optimization using complication probability models in intensity modulated radiotherapy (IMRT) planning has tremendous potential for reducing radiation-induced toxicity. Nevertheless, biological optimization is almost never clinically utilized, probably because of clinician confidence in, and familiarity with, physical dose-volume constraints. The method proposed here incorporates biological optimization after dose-volume constrained optimization so as to improve the dose distribution without detrimentally affecting the important reductions achieved by dose-volume optimization (DVO). Methods: Following DVO, the clinician/planner first identifies ''fixed points'' on the target and organ-at-risk (OAR) dose-volume histograms. These points represent important DVO plan qualities that are not to be violated within a specified tolerance. Biological optimization then maximally reduces a biological metric (illustrated with equivalent uniform dose (EUD) in this work) while keeping the fixed dose-volume points within tolerance limits, as follows. Incremental fluence adjustments are computed and applied to incrementally reduce the OAR EUDs while approximately maintaining the fixed points. This process of incremental fluence adjustment is iterated until the fixed points exceed tolerance. At this juncture, remedial fluence adjustments are computed and iteratively applied to bring the fixed points back within tolerance, without increasing OAR EUDs. This process of EUD reduction followed by fixed-point correction is repeated until no further EUD reduction is possible. The method is demonstrated in the context of a prostate cancer case and olfactory neuroblastoma case. The efficacy of EUD reduction after DVO is evaluated by comparison to an optimizer with purely biological (EUD) OAR objectives. Results: For both cases, EUD reduction after DVO additionally reduced doses, especially high doses, to normal organs. For the prostate case, bladder

  7. New roles of flavoproteins in molecular cell biology: an unexpected role for quinone reductases as regulators of proteasomal degradation.

    Science.gov (United States)

    Sollner, Sonja; Macheroux, Peter

    2009-08-01

    Quinone reductases are ubiquitous soluble enzymes found in bacteria, fungi, plants and animals. These enzymes utilize a reduced nicotinamide such as NADH or NADPH to reduce the flavin cofactor (either FMN or FAD), which then affords two-electron reduction of cellular quinones. Although the chemical nature of the quinone substrate is still a matter of debate, the reaction appears to play a pivotal role in quinone detoxification by preventing the generation of potentially harmful semiquinones. In recent years, an additional role of quinone reductases as regulators of proteasomal degradation of transcription factors and possibly intrinsically unstructured protein has emerged. To fulfil this role, quinone reductase binds to the core particle of the proteasome and recruits certain transcription factors such as p53 and p73alpha to the complex. The latter process appears to be governed by the redox state of the flavin cofactor of the quinone reductase, thus linking the stability of transcription factors to cellular events such as oxidative stress. Here, we review the current evidence for protein complex formation between quinone reductase and the 20S proteasome in eukaryotic cells and describe the regulatory role of this complex in stabilizing transcription factors by acting as inhibitors of their proteasomal degradation.

  8. Assessing the role of generalist predators in the biological control of alfalfa weevil (Coleoptera: Curculionidae)

    Science.gov (United States)

    The alfalfa weevil, Hypera postica (Gyllenhal), is a major and longstanding economic pest of alfalfa throughout much of the United States. While work on biological control of this species has disproportionately focused on introduced parasitoids, generalist predators are also considered potentially i...

  9. Carboxylic Acid Ionophores as Probes of the Role of Calcium in Biological Systems

    Science.gov (United States)

    Reed, P. W.

    1983-01-01

    The biological effects of calcium ionophores are described, focusing on arachidonic acid oxygenation, and the formation of a number of oxygenated metabolites of arachidonic acid. These metabolites are involved in a number of bodily functions, and their production may be regulated by calcium.

  10. An expanded role for microbial physiology in metabolic engineering and functional genomics: moving towards systems biology

    DEFF Research Database (Denmark)

    Nielsen, Jens; Olsson, Lisbeth

    2002-01-01

    . With the progress in molecular biology it has become possible to optimize industrial fermentations through introduction of directed genetic modification - an approach referred to as metabolic engineering. Furthermore, as a consequence of large sequencing programs the complete genomic sequence has become available...

  11. Role of biologics targeting type 2 airway inflammation in asthma : What have we learned so far?

    NARCIS (Netherlands)

    Parulekar, Amit D.; Diamant, Zuzana; Hanania, Nicola A.

    2017-01-01

    Purpose of reviewSevere asthma is a heterogeneous syndrome that can be classified into distinct phenotypes and endotypes. In the type 2 (T2)-high endotype, multiple cytokines are produced that lead to eosinophilic inflammation. These cytokines and their receptors are targets for biologic therapies i

  12. Anxiety Symptoms in African American Youth: The Role of Puberty and Biological Sex

    Science.gov (United States)

    Carter, Rona

    2015-01-01

    This study examined the effects of pubertal status, pubertal timing (actual and perceived), and youth biological sex on symptom dimensions of anxiety (i.e., social, separation, harm avoidance, physical) in African Americans (n = 252; ages 8-12). For girls, results indicated that pubertal status and timing (actual) exerted similar effects for some…

  13. Nonlinear signaling on biological networks: The role of stochasticity and spectral clustering

    Science.gov (United States)

    Hernandez-Hernandez, Gonzalo; Myers, Jesse; Alvarez-Lacalle, Enrique; Shiferaw, Yohannes

    2017-03-01

    Signal transduction within biological cells is governed by networks of interacting proteins. Communication between these proteins is mediated by signaling molecules which bind to receptors and induce stochastic transitions between different conformational states. Signaling is typically a cooperative process which requires the occurrence of multiple binding events so that reaction rates have a nonlinear dependence on the amount of signaling molecule. It is this nonlinearity that endows biological signaling networks with robust switchlike properties which are critical to their biological function. In this study we investigate how the properties of these signaling systems depend on the network architecture. Our main result is that these nonlinear networks exhibit bistability where the network activity can switch between states that correspond to a low and high activity level. We show that this bistable regime emerges at a critical coupling strength that is determined by the spectral structure of the network. In particular, the set of nodes that correspond to large components of the leading eigenvector of the adjacency matrix determines the onset of bistability. Above this transition the eigenvectors of the adjacency matrix determine a hierarchy of clusters, defined by its spectral properties, which are activated sequentially with increasing network activity. We argue further that the onset of bistability occurs either continuously or discontinuously depending upon whether the leading eigenvector is localized or delocalized. Finally, we show that at low network coupling stochastic transitions to the active branch are also driven by the set of nodes that contribute more strongly to the leading eigenvector. However, at high coupling, transitions are insensitive to network structure since the network can be activated by stochastic transitions of a few nodes. Thus this work identifies important features of biological signaling networks that may underlie their biological

  14. [The Functional Role of Exosomes in Cancer Biology and Their Potential as Biomarkers and Therapeutic Targets of Cancer].

    Science.gov (United States)

    Naito, Yutaka; Yoshioka, Yusuke; Ochiya, Takahiro

    2015-06-01

    Intercellular communication plays an important role in the regulation of various cellular events. In particular, cancer cells and the surrounding cells communicate with each other, and this intercellular communication triggers cancer initiation and progression through the secretion of molecules, including growth factors and cytokines. Recent advances in cancer biology have indicated that small membrane vesicles, termed exosomes, also serve as regulatory agents in intercellular communications. Exosomes contain functional cellular components, including proteins and microRNAs (miRNAs), and they transfer these components to recipient cells. This exosome-mediated intercellular communication leads to increased growth, invasion, and metastasis of cancer. Thus, researchers regard exosomes as important cues to understanding the molecular mechanisms of cancer biology. Indeed, several lines of evidence have demonstrated that exosomes can explain multiple aspects of cancer biology. In addition, increasing evidence suggests that exosomes and their specific molecules are also attractive for use as biomarkers and therapeutic targets in cancer. Recent reports showed the efficacy of a novel diagnosis by detecting component molecules of cancer-derived exosomes, including miRNAs and membrane proteins. Furthermore, clinical trials that test the application of exosomes for cancer therapy have already been reported. From these points of view, we will summarize experimental data that support the role of exosomes in cancer progression and the potential of exosomes for use in novel diagnostic and therapeutic approaches for cancer.

  15. Role of vitamin A in type 2 diabetes mellitus biology: effects of intervention therapy in a deficient state.

    Science.gov (United States)

    Iqbal, Sarah; Naseem, Imrana

    2015-01-01

    Diabetes has emerged as the biggest pandemic of our times, growing parallel to obesity. Insulin treatment regimens have been unable to completely inhibit protein glycation, which is responsible for the development of increased oxidative stress in diabetic tissues. Coupled with recent evidences that highlight the role of reactive oxygen species in the onset and progression of type 2 diabetes mellitus (T2DM), the antioxidants have taken prime focus as a possible intervention strategy. Studies have established a role of antioxidant vitamins C and E in improving patient condition in the past. Vitamin A, in addition to its role as an antioxidant, boasts a pleiotropic role in cell regulation through its action on gene regulation, maintenance of epithelial cell integrity, and resistance to infection. Studies have also ascribed a role to vitamin A in up-regulating the antioxidant enzyme functions in the body. Additionally, a link has been found between diabetes and deficient vitamin A levels indicating vitamin A supplementation may have a role in T2DM biology. This review therefore focuses on the vitamin A intervention in T2DM patients having deficient in vitamin A.

  16. Carbon monoxide in biology and microbiology: surprising roles for the "Detroit perfume".

    Science.gov (United States)

    Davidge, Kelly S; Motterlini, Roberto; Mann, Brian E; Wilson, Jayne Louise; Poole, Robert K

    2009-01-01

    Carbon monoxide (CO) is a colorless, odorless gas with a reputation for being an anthropogenic poison; there is extensive documentation of the modes of human exposure, toxicokinetics, and health effects. However, CO is also generated endogenously by heme oxygenases (HOs) in mammals and microbes, and its extraordinary biological activities are now recognized and increasingly utilized in medicine and physiology. This review introduces recent advances in CO biology and chemistry and illustrates the exciting possibilities that exist for a deeper understanding of its biological consequences. However, the microbiological literature is scant and is currently restricted to: 1) CO-metabolizing bacteria, CO oxidation by CO dehydrogenase (CODH) and the CO-sensing mechanisms that enable CO oxidation; 2) the use of CO as a heme ligand in microbial biochemistry; and 3) very limited information on how microbes respond to CO toxicity. We demonstrate how our horizons in CO biology have been extended by intense research activity in recent years in mammalian and human physiology and biochemistry. CO is one of several "new" small gas molecules that are increasingly recognized for their profound and often beneficial biological activities, the others being nitric oxide (NO) and hydrogen sulfide (H2S). The chemistry of CO and other heme ligands (oxygen, NO, H2S and cyanide) and the implications for biological interactions are briefly presented. An important advance in recent years has been the development of CO-releasing molecules (CO-RMs) for aiding experimental administration of CO as an alternative to the use of CO gas. The chemical principles of CO-RM design and mechanisms of CO release from CO-RMs (dissociation, association, reduction and oxidation, photolysis, and acidification) are reviewed and we present a survey of the most commonly used CO-RMs. Amongst the most important new applications of CO in mammalian physiology and medicine are its vasoactive properties and the

  17. Understanding the Biological Roles of Pectins in Plants through Physiological and Functional Characterizations of Plant and Fungal Mutants

    DEFF Research Database (Denmark)

    Stranne, Maria

    The plant cell wall is a dynamic structure and it is involved in regulating a number of physiological features of plants such as physical strength, growth, cell differentiation, intercellular communication, water movement and defense responses. Pectins constitute a major class of plant cell wall...... aspects remain elusive. Studies described in this thesis aimed at gaining new insights into the biological roles of pectin acetylation and arabinosylation in the model plant Arabidopsis thaliana. The thesis consists of four chapters: physiological characterization of cell wall mutants affected in cell...... polysaccharides and consist of backbones rich in galacturonic acids, which are decorated with a range of functional groups including acetyl esters and arabinan sidechains. Although much effort has been made to uncover biological functions of pectins in plants and remarkable progresses have taken place, many...

  18. Individuals and populations: the role of long-term, individual-based studies of animals in ecology and evolutionary biology.

    Science.gov (United States)

    Clutton-Brock, Tim; Sheldon, Ben C

    2010-10-01

    Many important questions in ecology and evolutionary biology can only be answered with data that extend over several decades and answering a substantial proportion of questions requires records of the life histories of recognisable individuals. We identify six advantages that long-term, individual based studies afford in ecology and evolution: (i) analysis of age structure; (ii) linkage between life history stages; (iii) quantification of social structure; (iv) derivation of lifetime fitness measures; (v) replication of estimates of selection; (vi) linkage between generations, and we review their impact on studies in six key areas of evolution and ecology. Our review emphasises the unusual opportunities and productivity of long-term, individual-based studies and documents the important role that they play in research on ecology and evolutionary biology as well as the difficulties they face.

  19. Non-replication of genome-wide based associations between common variants in INSIG2 and PFKP and obesity in studies of 18,014 Danes.

    Directory of Open Access Journals (Sweden)

    Camilla H Andreasen

    Full Text Available BACKGROUND: The INSIG2 rs7566605 and PFKP rs6602024 polymorphisms have been identified as obesity gene variants in genome-wide association (GWA studies. However, replication has been contradictory for both variants. The aims of this study were to validate these obesity-associations through case-control studies and analyses of obesity-related quantitative traits. Moreover, since environmental and genetic factors may modulate the impact of a genetic variant, we wanted to perform such interaction analyses. We focused on physical activity as an environmental risk factor, and on the GWA identified obesity variants in FTO (rs9939609 and near MC4R (rs17782313 as genetic risk factors. MATERIALS AND METHODS: The four variants were genotyped in a combined study sample comprising a total of 18,014 subject ascertained from, the population-based Inter99 cohort (n = 6,514, the ADDITION screening cohort (n = 8,662, a population-based study sample (n = 680 and a type 2 diabetic patient group (n = 2,158 from Steno Diabetes Center. RESULTS: No association with overweight, obesity or obesity-related measures was shown for either the INSIG2 rs7566605 or the PFKP rs6602024 variants. However, an interaction between the INSIG2 rs7566605 variant and the level of self-reported physical activity (p(Int = 0.004 was observed. A BMI difference of 0.53 (SE 0.42 kg/m(2 was found when comparing physically passive homozygous C-allele carriers with physically passive G-allele carriers. No interactions between the two variants and FTO rs9939609 and MC4R rs17782313 were observed. CONCLUSIONS: The INSIG2 rs7566605 and PFKP rs6602024 polymorphisms play no apparent role in the development of common forms of obesity in the Danish population. However, if replicated, the INSIG2 rs7566605 may influence the level of BMI in combination with the level of physical activity.

  20. Role of peptide bond in the realization of biological activity of short peptides.

    Science.gov (United States)

    Khavinson, V Kh; Tarnovskaya, S I; Lin'kova, N S; Chervyakova, N A; Nichik, T E; Elashkina, E V; Chalisova, N I

    2015-02-01

    We performed a comparative analysis of biological activity of Lys-Glu peptide and its amino acid constituents. It was established that Lys-Glu stimulated proliferation of splenic cells in organotypic culture, while the mixture of glutamic acid and lysine inhibited culture growth. Using the method of molecular docking, we showed that glutamic acid, lysine, and Lys-Glu peptide can interact with different DNA sequences. The energy of interaction and the most beneficial localization of glutamic acid, lysine, and Lys-Glu peptide in DNA molecule was calculated. We demonstrated the interaction of the peptide and amino acids with DNA along the minor groove. The energy of DNA interaction with the peptide is higher than with individual amino acids. The peptide bonds increase the interaction of Lys-Glu peptide with DNA, which potentiates the biological effect on cell proliferation in organotypic culture of splenic cells.

  1. [THE ROLE OF BIOLOGICAL MEMBRANES IN DIFFERENTIAL DIAGNOSTICS OF SALMONELLA AND ACUTE ALCOHOL GASTROENTERITIS].

    Science.gov (United States)

    Makarov, V K; Makarov, P V

    2015-01-01

    We evaluated the influence of Salmonella infection and alcohol on biological membranes from the content of serum phospholipid fraction known to be a component ofenterocyte membranes. Any change of membrane phospholipid content leads to a change of their blood level. The study included 50 patients with acute alcohol gastroenteritis, 50 ones with salmonella gastroenteritis, and 50 healthy subjects. Both salmonellosis and alcohol caused differently directed changes in biological membranes. The mechanism of diarrhea in patients with salmonella and acute alcohol gastroenteritis is different. Diarrhea associated with alcohol gastroenteritis is due to enhanced viscosity of biomembranes that decreases in salmonella gastroenteritis. It suggests different approaches to the treatment of these conditions. The membrane destruction coefficient below 2 is an additional proof of alcoholic etiology of gastroenteritis whereas its value above 3 confirms the involvement of salmonellosis in pathogenesis of gastroenteritis.

  2. Role of conventional therapies in the era of biological treatment in Crohn's disease

    Institute of Scientific and Technical Information of China (English)

    Paolo Gionchetti; Fernando Rizzello; Carlo Calabrese; Rosy Tambasco; Ramona Brugnera; Giulia Straforini; Giuseppina Liguori; Giulia Spuri Fornarini; Donatella Riso; Massimo Campieri

    2011-01-01

    Outstanding progress regarding the pathophysiology of Crohn's disease (CD) has led to the development of innovative therapeutic concepts.Numerous controlled trials have been performed in CD.This review concentrates on the results of randomized, placebo-controlled trials, and meta-analyses when available, that provide the highest degree of evidence.Current guidelines on the management of CD recommend a step-up approach to treatment involving the addition of more powerful therapies as the severity of disease and refractoriness to therapy increase.The advent of biological drugs has opened new therapeutic horizons for treating CD, modifying the treatment goals.However, the large majority of patients with CD will be managed through conventional therapy, even if they are a prelude to biological therapy.

  3. New insight into the biological treatment by activated sludge: the role of adsorption process.

    Science.gov (United States)

    Zhang, Xiaochun; Li, Xinrun; Zhang, Qingrui; Peng, Qiuming; Zhang, Wen; Gao, Faming

    2014-02-01

    The objective of this study was to evaluate the effect of adsorption on the biological treatment process of wastewater. In the absence of substrate in the water, activated sludge developed well in the first hour, indicating that the growth of microorganism was not directly related to substrate concentration and the dissolved organic matter in the water assays were performed, no organic matter was detected out, revealing that there was no desorption in the activated sludge adsorption process. Activated sludge batch growth experiments in the presence of different adsorption capacities indicated that specific growth rate increased as specific adsorption capacity increased. The experiment on the relationship of adsorption capacity and substrate concentration or sludge concentration was also carried out. Specific adsorption capacity increased as sludge load increased, presenting linear correlation. The experiment results showed that adsorption should be taken into account in the study of the biological treatment process of wastewater.

  4. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  5. The Role of Molecular Biology in the Biomonitoring of Human Exposure to Chemicals

    OpenAIRE

    Balam Muñoz; Arnulfo Albores

    2010-01-01

    Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring ...

  6. The Role of Field Classes in Education of Prospective Teachers in Biology

    Directory of Open Access Journals (Sweden)

    E. Fleszar

    2009-12-01

    Full Text Available Field classes are indispensable in education of biology and environment protection students, as they allow a future teacher to carry out teaching material bringing together theory and practice through activity. In the framework of Biology Didactics classes the biology students of the Faculty of Natural Sciences at the University of Szczecin participate actively in the works on didactic nature trail in the Arkoñski Woods prepared by Dr. Ewa Fleszar. During the work on didactic natural path the students make themselves acquainted with: field class objectives; field class tasks; field class programmes, e.g. concerning phenology; flora and fauna species. Writing synopsis of field classes for selected lesson units at different teaching levels they acquire sound knowledge based on the ecological contents. Contacts with nature as well as gaining the experience during field classes allow them to obtain competences for working in the field and to understand the objectives of carrying out such classes. Field classes have an effect on developing interests of participants in the subject, and affect the improvement of teaching performance. Visit to the field forms ecological awareness, which leads to obtaining an ecological culture.

  7. Understanding the role of ETS-mediated gene regulation in complex biological processes.

    Science.gov (United States)

    Findlay, Victoria J; LaRue, Amanda C; Turner, David P; Watson, Patricia M; Watson, Dennis K

    2013-01-01

    Ets factors are members of one of the largest families of evolutionarily conserved transcription factors, regulating critical functions in normal cell homeostasis, which when perturbed contribute to tumor progression. The well-documented alterations in ETS factor expression and function during cancer progression result in pleiotropic effects manifested by the downstream effect on their target genes. Multiple ETS factors bind to the same regulatory sites present on target genes, suggesting redundant or competitive functions. The anti- and prometastatic signatures obtained by examining specific ETS regulatory networks will significantly improve our ability to accurately predict tumor progression and advance our understanding of gene regulation in cancer. Coordination of multiple ETS gene functions also mediates interactions between tumor and stromal cells and thus contributes to the cancer phenotype. As such, these new insights may provide a novel view of the ETS gene family as well as a focal point for studying the complex biological control involved in tumor progression. One of the goals of molecular biology is to elucidate the mechanisms that contribute to the development and progression of cancer. Such an understanding of the molecular basis of cancer will provide new possibilities for: (1) earlier detection, as well as better diagnosis and staging of disease; (2) detection of minimal residual disease recurrences and evaluation of response to therapy; (3) prevention; and (4) novel treatment strategies. Increased understanding of ETS-regulated biological pathways will directly impact these areas. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Reproductive biology of Echinopsis terscheckii (Cactaceae): the role of nocturnal and diurnal pollinators.

    Science.gov (United States)

    Ortega-Baes, P; Saravia, M; Sühring, S; Godínez-Alvarez, H; Zamar, M

    2011-01-01

    The aim of this study was to analyse the reproductive biology of Echinopsis terscheckii, a species endemic to northwest Argentina that has nocturnal flowers. We expected that this species had a generalised pollination system, with moths and diurnal visitors as the primary pollinators. To test this, we studied the floral biology, breeding system and floral visitors of this species and the effectiveness of nocturnal and diurnal visitors. Floral biology was defined based on floral morphology, floral cycle and nectar production of the flowers. The breeding system and relative contributions of diurnal and nocturnal visitors to fruit and seed set were analysed through field experiments. E. terscheckii flowers opened at sunset and closed the following day. The peak of nectar production occurred at midnight. Flowers were determined to be self-incompatible. Moths, bees and birds were identified as floral visitors. Moths were the most frequent visitors at night, whereas bees were the most frequent visitors during the day. Fruit production by diurnal pollinators was less than that by nocturnal pollinators; among all floral visitors, moths were the most effective pollinators. We have demonstrated for the first time that moths are the primary pollinators of columnar cacti of the genus Echinopsis. Our results suggest that moths might be important pollinators of columnar cactus species with nocturnal flowers in the extra-tropical deserts of South America.

  9. The role of cell hydration in realization of biological effects of non-ionizing radiation (NIR).

    Science.gov (United States)

    Ayrapetyan, Sinerik

    2015-09-01

    The weak knowledge on the nature of cellular and molecular mechanisms of biological effects of NIR such as static magnetic field, infrasound frequency of mechanical vibration, extremely low frequency of electromagnetic fields and microwave serves as a main barrier for adequate dosimetry from the point of Public Health. The difficulty lies in the fact that the biological effects of NIR depend not only on their thermodynamic characteristics but also on their frequency and intensity "windows", chemical and physical composition of the surrounding medium, as well as on the initial metabolic state of the organism. Therefore, only biomarker can be used for adequate estimation of biological effect of NIR on organisms. Because of the absence of such biomarker(s), organizations having the mission to monitor hazardous effects of NIR traditionally base their instruction on thermodynamic characteristics of NIR. Based on the high sensitivity to NIR of both aqua medium structure and cell hydration, it is suggested that cell bathing medium is one of the primary targets and cell hydration is a biomarker for NIR effects on cells and organisms. The purpose of this article is to present a short review of literature and our own experimental data on the effects of NIR on plants' seeds germination, microbe growth and development, snail neurons and heart muscle, rat's brain and heart tissues.

  10. Cl- and K+ channels and their role in primary brain tumour biology.

    Science.gov (United States)

    Turner, Kathryn L; Sontheimer, Harald

    2014-03-19

    Profound cell volume changes occur in primary brain tumours as they proliferate, invade surrounding tissue or undergo apoptosis. These volume changes are regulated by the flux of Cl(-) and K(+) ions and concomitant movement of water across the membrane, making ion channels pivotal to tumour biology. We discuss which specific Cl(-) and K(+) channels are involved in defined aspects of glioma biology and how these channels are regulated. Cl(-) is accumulated to unusually high concentrations in gliomas by the activity of the NKCC1 transporter and serves as an osmolyte and energetic driving force for volume changes. Cell volume condensation is required as cells enter M phase of the cell cycle and this pre-mitotic condensation is caused by channel-mediated ion efflux. Similarly, Cl(-) and K(+) channels dynamically regulate volume in invading glioma cells allowing them to adjust to small extracellular brain spaces. Finally, cell condensation is a hallmark of apoptosis and requires the concerted activation of Cl(-) and Ca(2+)-activated K(+) channels. Given the frequency of mutation and high importance of ion channels in tumour biology, the opportunity exists to target them for treatment.

  11. Fetal Programming of Body Composition, Obesity, and Metabolic Function: The Role of Intrauterine Stress and Stress Biology

    Science.gov (United States)

    Entringer, Sonja; Buss, Claudia; Swanson, James M.; Cooper, Dan M.; Wing, Deborah A.; Waffarn, Feizal; Wadhwa, Pathik D.

    2012-01-01

    Epidemiological, clinical, physiological, cellular, and molecular evidence suggests that the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. In this perspectives paper we propose that in addition to maternal nutrition-related processes it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition), on brain and peripheral targets of programming of body composition, energy balance homeostasis, and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate mechanisms that may underlie the long-term effects of intrauterine stress. We conclude with a commentary of the implications for future research and clinical practice. PMID:22655178

  12. Fetal Programming of Body Composition, Obesity, and Metabolic Function: The Role of Intrauterine Stress and Stress Biology

    Directory of Open Access Journals (Sweden)

    Sonja Entringer

    2012-01-01

    Full Text Available Epidemiological, clinical, physiological, cellular, and molecular evidence suggests that the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. In this perspectives paper we propose that in addition to maternal nutrition-related processes it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition, on brain and peripheral targets of programming of body composition, energy balance homeostasis, and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate mechanisms that may underlie the long-term effects of intrauterine stress. We conclude with a commentary of the implications for future research and clinical practice.

  13. Evaluation of the biological role in the shore platform evolution. Development of specific methodology and first results.

    Science.gov (United States)

    Neves, Mario; Ramos-Pereira, Ana; Moura, Delminda; Trindade, Jorge; Gusmão, Francisca; Viegas, José; Santana, Paulo

    2010-05-01

    The formation and the evolution of shore platforms are dependent on several physical, chemical and biological processes. The weight of each of these processes is changeable not only from coast to coast but also within each shore platform. It depends on geographical, geomorphological, climatic and wave climate factors. In the lower intertidal zone of many rock coasts of the world, the biological cover of the surface is extremely high. This almost permanent wrap points out to a very strong biological influence on the downwearing rates and the erosive rhythm of these strips of the shore platforms. Yet, although there are several studies on the erosive ability of the individuals of each species that are found here, analyzed separately, research on the interactions among species with erosive and protective role in the present evolution of shore platforms are rare. The goal of the BISHOP Project - Bioprotection and bioerosion on shore platforms in the Algarve and Estremadura (Portugal South and West Coast) - is precisely to evaluate the bioprotective and bioerosive role of the communities of macro-organisms in the evolution of shore platforms cut in different type of rocks and in assorted environments. With that purpose, it was necessary to develop specific methodology. To quantify the downwearing of the shore platform, we used a TMEM (Traversing Micro-Erosion Meter) with an accuracy of 0,005mm, and capable of measuring 255 points in a 117 cm2 area. Four experimental places were chosen: two at calcarenite shore platforms of the Portuguese south coast, in a coastal zone exposed to the south and sheltered from the waves; and two in the Portuguese Estremadura, facing west on a well exposed coast to the North Atlantic energetic waves, on shore platforms cut in marly limestone. At each place, two pairs of monitoring areas were installed. For each pair, the same methodology was used. At the beginning, it was necessary to completely clean the biological cover of the two areas

  14. The role of socioscientific issues in biology teaching – from the perspective of teachers

    DEFF Research Database (Denmark)

    Tidemand, Sofie; Nielsen, Jan Alexis

    2016-01-01

    documented that a range of challenges hinders the uptake of socioscientific issues. In this study we investigated the interpretation and implementation of socioscientific issues among Danish biology teachers – who teach in a curriculum that, on paper, is permeated by socioscientific issues. We conducted five...... in-depth group interviews (with a total of 11 teachers) and sought to validate and expand on the emergent themes from the teachers’ talk-in-interaction by distributing a wider, primarily open-ended questionnaire (100 responding teachers). Our findings suggest that the participating teachers generally...

  15. Prognosis and biology in esthesioneuroblastoma: the emerging role of Hyams grading system.

    Science.gov (United States)

    Saade, Rami E; Hanna, Ehab Y; Bell, Diana

    2015-01-01

    Esthesioneuroblastoma is a sinonasal tumor with distinct clinicopathologic features, multiple facets, and a spectrum of behavior. Characterization of this disease is challenging, and clinically, several staging systems have been used with no consensus on a single scheme. Recently, the Hyams histological grading system has emerged as a promising prognostication tool that offers an added value to stage. This review addresses prognosis and biology in esthesioneuroblastoma. More specifically, we sought to present a critical appraisal on the value of each of these stratification systems, stage vs. grade, in identifying risk groups and guiding management.

  16. The role of the molecular biology laboratory in the management of chronic hepatitis B and C

    Directory of Open Access Journals (Sweden)

    Peter Karayiannis

    2013-03-01

    Full Text Available Molecular biology techniques are routinely used nowadays to diagnose and evaluate antiviral treatment of patients with chronic hepatitis B (HBV and hepatitis C virus (HCV infections. Current tools at our disposal include tests that quantify the amount of circulating virus in the blood, techniques that can analyse genomic sequences to determine viral genotypes or subtypes, or determine amino-acid substitutions that may confer resistance to existing antiviral drugs. What is more, continuously evolving serological tests for the detection of viral antigens or their corresponding antibodies, have made diagnosis of disease as sensitive as possible. The present review will concentrate primarily on molecular diagnostics.

  17. [The integrating role of biological motivation in the realization of feeding and drinking behaviors].

    Science.gov (United States)

    Kromin, A A

    1991-01-01

    In chronic experiments on rabbits with preliminary alimentary or water deprivation electrical and mechanic activity was studied of the chewer muscle proper and of the esophagus in the process of animals food or water taking. It has been established that in patterns of electrical and mechanic activity of the chewer muscle proper and esophagus specific differences of alimentary and drinking behaviour of animals are reflected. Dominating motivation of different biological properties determines the specific integration of motoneurones of chewing and swallowing centers and peripheral contraction elements of digestive tract in the functional systems of alimentary and drinking behaviour.

  18. Measurement of melatonin and its metabolites: importance for the evaluation of their biological roles.

    Science.gov (United States)

    Martinez, Glaucia R; Almeida, Eduardo A; Klitzke, Clécio F; Onuki, Janice; Prado, Fernanda M; Medeiros, Marisa H G; Di Mascio, Paolo

    2005-07-01

    Many physiologic changes related to light-dark cycles and antioxidant effects have been related to melatonin (N-acetyl-5-methoxytryptamine) and its metabolites, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK). In this review, we discuss some methodologies, in particular, those employing high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) assays to quantitatively determine melatonin, AFMK, and AMK. These approaches offer a highly specific and an accurate quantification of melatonin and its metabolites. These characteristics are essential to point out correctly the biological effects of these compounds in physiological and pathological conditions.

  19. Perspectives on the role of Pannexin 1 in neural precursor cell biology

    Institute of Scientific and Technical Information of China (English)

    Juan C Sanchez-Arias; Leigh E Wicki-Stordeur; Leigh Anne Swayne

    2016-01-01

    We recently reported that targeted deletion of Pannexin 1 in neural precursor cells of the ventricular zone impairs the maintenance of these cells in healthy and stroke-injured brain. Here we frame this exciting new ifnding in the context of our previous studies on Pannexin 1 in neural precursors as well as the close rela-tionship between Pannexin 1 and purinergic receptors established by other groups. Moreover, we identify important gaps in our understanding of Pannexin 1 in neural precursor cell biology in terms of the under-lying molecular mechanisms and functional/behavioural outcomes.

  20. Insights into the key roles of proteoglycans in breast cancer biology and translational medicine

    DEFF Research Database (Denmark)

    Theocharis, Achilleas D.; Skandalis, Spyros S.; Neill, Thomas

    2015-01-01

    of proteoglycans on tumor and stromal cell membranes affects cancer cell signaling, growth and survival, cell adhesion, migration and angiogenesis. Despite the high complexity and heterogeneity of breast cancer, the rapid evolution in our knowledge that proteoglycans are among the key players in the breast tumor...... in the proteoglycans that will be presented herein provides the potential for multiple layers of regulation of breast tumor behavior. This review summarizes recent developments concerning the biology of selected proteoglycans in breast cancer, and presents potential targeted therapeutic approaches based on their novel...

  1. Role of the phenolic hydroxyl group in the biological activities of simplified analogue of aplysiatoxin with antiproliferative activity.

    Science.gov (United States)

    Yanagita, Ryo C; Kamachi, Hiroaki; Tanaka, Keisuke; Murakami, Akira; Nakagawa, Yu; Tokuda, Harukuni; Nagai, Hiroshi; Irie, Kazuhiro

    2010-10-15

    The 18-deoxy derivative (3) of a simplified analogue (1) of aplysiatoxin with antiproliferative activity was synthesized to examine the role of the phenolic hydroxyl group at position 18 in the biological activities of 1. Compound 3 as well as 1 showed significant affinity for protein kinase Cδ (PKCδ), and the antiproliferative activity of 3 was slightly higher than that of 1. However, the anti-tumor-promoting activity of 3 was less than that of 1 in vitro, suggesting that the phenolic hydroxyl group of 1 is necessary for the anti-tumor-promoting activity but not for the binding of PKCδ and antiproliferative activity. Moreover, PKC isozyme selectivity of 3 was similar to that of 1, suggesting non-PKC receptors for these compounds to play some roles in the anti-tumor-promoting activity of 1.

  2. The Role of Stochastic Models in Interpreting the Origins of Biological Chirality

    Directory of Open Access Journals (Sweden)

    Gábor Lente

    2010-04-01

    Full Text Available This review summarizes recent stochastic modeling efforts in the theoretical research aimed at interpreting the origins of biological chirality. Stochastic kinetic models, especially those based on the continuous time discrete state approach, have great potential in modeling absolute asymmetric reactions, experimental examples of which have been reported in the past decade. An overview of the relevant mathematical background is given and several examples are presented to show how the significant numerical problems characteristic of the use of stochastic models can be overcome by non-trivial, but elementary algebra. In these stochastic models, a particulate view of matter is used rather than the concentration-based view of traditional chemical kinetics using continuous functions to describe the properties system. This has the advantage of giving adequate description of single-molecule events, which were probably important in the origin of biological chirality. The presented models can interpret and predict the random distribution of enantiomeric excess among repetitive experiments, which is the most striking feature of absolute asymmetric reactions. It is argued that the use of the stochastic kinetic approach should be much more widespread in the relevant literature.

  3. Role of Moving Bed Biofilm Reactor and Sequencing Batch Reactor in Biological Degradation of Formaldehyde Wastewater

    Directory of Open Access Journals (Sweden)

    B. Ayati

    2011-10-01

    Full Text Available Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR and sequencing batch reactors (SBR were investigated. During all experiments, the efficiency of SBR was more than MBBR, but the difference was not significant statistically. According to the results, the best efficiencies were obtained for influent formaldehyde COD of 200 mg/L in MBBR and SBR which were 93% and 99.4%, respectively. The systems were also capable to treat higher formaldehyde concentrations (up to 2500 mg/L with lower removal efficiency. The reaction kinetics followed the Stover-Kincannon second order model. The gram-positive and gram-negative bacillus and coccus as well as the gram-positive binary bacillus were found to be the most dominant species. The results of 13C-NMR analysis have shown that formaldehyde and urea were converted into N-{[(aminocarbonyl amino] methyl}urea and the residual formaldehyde was polymerized at room temperature.

  4. The role of bacillus-based biological control agents in integrated pest management systems: plant diseases.

    Science.gov (United States)

    Jacobsen, B J; Zidack, N K; Larson, B J

    2004-11-01

    ABSTRACT Bacillus-based biological control agents (BCAs) have great potential in integrated pest management (IPM) systems; however, relatively little work has been published on integration with other IPM management tools. Unfortunately, most research has focused on BCAs as alternatives to synthetic chemical fungicides or bactericides and not as part of an integrated management system. IPM has had many definitions and this review will use the national coalition for IPM definition: "A sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks." This review will examine the integrated use of Bacillus-based BCAs with disease management tools, including resistant cultivars, fungicides or bactericides, or other BCAs. This integration is important because the consistency and degree of disease control by Bacillus-based BCAs is rarely equal to the control afforded by the best fungicides or bactericides. In theory, integration of several tools brings stability to disease management programs. Integration of BCAs with other disease management tools often provides broader crop adaptation and both more efficacious and consistent levels of disease control. This review will also discuss the use of Bacillus-based BCAs in fungicide resistance management. Work with Bacillus thuringiensis and insect pest management is the exception to the relative paucity of reports but will not be the focus of this review.

  5. The role of ontologies in biological and biomedical research: a functional perspective

    KAUST Repository

    Hoehndorf, Robert

    2015-04-10

    Ontologies are widely used in biological and biomedical research. Their success lies in their combination of four main features present in almost all ontologies: provision of standard identifiers for classes and relations that represent the phenomena within a domain; provision of a vocabulary for a domain; provision of metadata that describes the intended meaning of the classes and relations in ontologies; and the provision of machine-readable axioms and definitions that enable computational access to some aspects of the meaning of classes and relations. While each of these features enables applications that facilitate data integration, data access and analysis, a great potential lies in the possibility of combining these four features to support integrative analysis and interpretation of multimodal data. Here, we provide a functional perspective on ontologies in biology and biomedicine, focusing on what ontologies can do and describing how they can be used in support of integrative research. We also outline perspectives for using ontologies in data-driven science, in particular their application in structured data mining and machine learning applications.

  6. Low-Molecular-Weight Metabolites from Diatoms: Structures, Biological Roles and Biosynthesis

    Directory of Open Access Journals (Sweden)

    Valentin Stonik

    2015-06-01

    Full Text Available Diatoms are abundant and important biological components of the marine environment that biosynthesize diverse natural products. These microalgae are rich in various lipids, carotenoids, sterols and isoprenoids, some of them containing toxins and other metabolites. Several groups of diatom natural products have attracted great interest due to their potential practical application as energy sources (biofuel, valuable food constituents, and prospective materials for nanotechnology. In addition, hydrocarbons, which are used in climate reconstruction, polyamines which participate in biomineralization, new apoptotic agents against tumor cells, attractants and deterrents that regulate the biochemical communications between marine species in seawaters have also been isolated from diatoms. However, chemical studies on these microalgae are complicated by difficulties, connected with obtaining their biomass, and the influence of nutrients and contaminators in their environment as well as by seasonal and climatic factors on the biosynthesis of the corresponding natural products. Overall, the number of chemically studied diatoms is lower than that of other algae, but further studies, particularly those connected with improvements in the isolation and structure elucidation technique as well as the genomics of diatoms, promise both to increase the number of studied species with isolated biologically active natural products and to provide a clearer perception of their biosynthesis.

  7. Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results

    Science.gov (United States)

    Banin, A.; Rishpon, J.

    1979-01-01

    Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.

  8. The Role of Carrier Geometry in Overcoming Biological Barriers to Drug Delivery.

    Science.gov (United States)

    Jordan, Carolyn; Shuvaev, Vladimir V; Bailey, Mark; Muzykantov, Vladimir R; Dziubla, Thomas D

    2016-01-01

    For a variety of diseases, effective therapy is severely limited or rendered impossible due to an inability to deliver medications to the intended sites of action. Multiple barriers exist through the body, which have evolved over time to limit the migration of foreign compounds from entering the tissues. Turning toward biology as inspiration, it has been the general goal of drug delivery to create carrier strategies that mimic, in part, features of bacteria/ viruses that allow them overcome these barriers. By packaging drugs into nano and micron scale vehicles, it should be possible to completely change the biodistribution and residence times of pharmaceutically active compounds. Recently, due to advances in formulation technologies, it has become possible to control not just the material selection, surface chemistry, and/or size, but also the overall geometry and plasticity of the drug carriers. These approaches aid in the formulation of nonspherical particles such as, discs, rods, and even unique structures such as cubes and nanodiamonds. The adjustment of size and shape can be used for the aid or prevention in cellular uptake and also to overcome the vascular and mucosal barrier. In this review, we present a summary of some approaches used to control carrier shape and the impact these geometries have upon drug transport across biological barriers.

  9. Anthropogenic climate change and allergen exposure: The role of plant biology.

    Science.gov (United States)

    Ziska, Lewis H; Beggs, Paul J

    2012-01-01

    Accumulation of anthropogenic gases, particularly CO(2), is likely to have 2 fundamental effects on plant biology. The first is an indirect effect through Earth's increasing average surface temperatures, with subsequent effects on other aspects of climate, such as rainfall and extreme weather events. The second is a direct effect caused by CO(2)-induced stimulation of photosynthesis and plant growth. Both effects are likely to alter a number of fundamental aspects of plant biology and human health, including aerobiology and allergic diseases, respectively. This review highlights the current and projected effect of increasing CO(2) and climate change in the context of plants and allergen exposure, emphasizing direct effects on plant physiologic parameters (eg, pollen production) and indirect effects (eg, fungal sporulation) related to diverse biotic and abiotic interactions. Overall, the review assumes that future global mitigation efforts will be limited and suggests a number of key research areas that will assist in adapting to the ongoing challenges to public health associated with increased allergen exposure.

  10. The role of ontologies in biological and biomedical research: a functional perspective.

    Science.gov (United States)

    Hoehndorf, Robert; Schofield, Paul N; Gkoutos, Georgios V

    2015-11-01

    Ontologies are widely used in biological and biomedical research. Their success lies in their combination of four main features present in almost all ontologies: provision of standard identifiers for classes and relations that represent the phenomena within a domain; provision of a vocabulary for a domain; provision of metadata that describes the intended meaning of the classes and relations in ontologies; and the provision of machine-readable axioms and definitions that enable computational access to some aspects of the meaning of classes and relations. While each of these features enables applications that facilitate data integration, data access and analysis, a great potential lies in the possibility of combining these four features to support integrative analysis and interpretation of multimodal data. Here, we provide a functional perspective on ontologies in biology and biomedicine, focusing on what ontologies can do and describing how they can be used in support of integrative research. We also outline perspectives for using ontologies in data-driven science, in particular their application in structured data mining and machine learning applications.

  11. The role of fractional calculus in modeling biological phenomena: A review

    Science.gov (United States)

    Ionescu, C.; Lopes, A.; Copot, D.; Machado, J. A. T.; Bates, J. H. T.

    2017-10-01

    This review provides the latest developments and trends in the application of fractional calculus (FC) in biomedicine and biology. Nature has often showed to follow rather simple rules that lead to the emergence of complex phenomena as a result. Of these, the paper addresses the properties in respiratory lung tissue, whose natural solutions arise from the midst of FC in the form of non-integer differ-integral solutions and non-integer parametric models. Diffusion of substances in human body, e.g. drug diffusion, is also a phenomena well known to be captured with such mathematical models. FC has been employed in neuroscience to characterize the generation of action potentials and spiking patters but also in characterizing bio-systems (e.g. vegetable tissues). Despite the natural complexity, biological systems belong as well to this class of systems, where FC has offered parsimonious yet accurate models. This review paper is a collection of results and literature reports who are essential to any versed engineer with multidisciplinary applications and bio-medical in particular.

  12. How old do you feel? The role of age discrimination and biological aging in subjective age.

    Directory of Open Access Journals (Sweden)

    Yannick Stephan

    Full Text Available Subjective age, or how young or old individuals experience themselves to be relative to their chronological age, is a crucial construct in gerontology. Subjective age is a significant predictor of important health outcomes, but little is known about the criteria by which individuals' subjectively evaluate their age. To identify psychosocial and biomedical factors linked to the subjective evaluation of age, this study examined whether perceived age discrimination and markers of biological aging are associated with subjective age. Participants were 4776 adults (Mage = 68 from the 2008 and 2010 waves of the Health and Retirement Study (HRS who completed measures of subjective age, age discrimination, demographic variables, self-rated health and depression, and had physical health measures, including peak expiratory flow, grip strength, waist circumference, systolic and diastolic blood pressure. Telomere length was available for a subset of participants in the 2008 wave (n = 2214. Regression analysis indicated that perceived age discrimination, lower peak expiratory flow, lower grip strength, and higher waist circumference were associated with an older subjective age, controlling for sociodemographic factors, self-rated health, and depression. In contrast, blood pressure and telomere length were not related to subjective age. These findings are consistent with the hypothesis that how old a person feels depends in part on psychosocial and biomedical factors, including the experiences of ageism and perceptible indices of fitness and biological age.

  13. [Biological role and importance in the skin metabolism of vitamin C].

    Science.gov (United States)

    Kleszczewska, Ewa

    2007-12-01

    Vitamins are a group of compounds indispensable for the development, normal growth and functioning of the human body. Lack of vitamins causes serious diseases for human, even though small amounts of them are required to maintain good health. Therefore there is growing interest conceding the role of vitamin C in biochemical-physiological conditions. This article reviews the role of water--soluble vitamin C in metabolic processes and discusses criteria used for recommended ingestion and presents recommendations for vitamin C intake. In the paper is discussed in detail the influence of level vitamin C (physico-chemical aspects) on the metabolism in skin.

  14. The roles of loosely-bound and tightly-bound extracellular polymer substances in enhanced biological phosphorus removal.

    Science.gov (United States)

    Long, Xiangyu; Tang, Ran; Fang, Zhendong; Xie, Chaoxin; Li, Yongqin; Xian, Guang

    2017-09-22

    Extracellular polymeric substances (EPS) have be founded to participate in the process of enhanced biological phosphorus removal (EBPR), but the exact role of EPS in EBPR process is unclear. In this work, the roles of loosely-bound EPS (LB-EPS), tightly-bound EPS (TB-EPS) and microbial cell in EBPR were explored, taking the activated sludge from 4 lab-scale A/O-SBR reactors with different temperatures and organic substrates as objects. It was founded that the P of EBPR activated sludge was mainly stored in TB-EPS, but the P of non-EBPR activated sludge was primarily located in microbial cell. The P release and uptake of EBPR activated sludge was attributed to the combined action of TB-EPS and microbial cell. Furthermore, TB-EPS played an more important role than microbial cell in EBPR process. With the analysis of (31)P NMR spectroscopy, both polyP and orthoP were the main phosphorus species of TB-EPS in EBPR sludge, but only orthoP was the main phosphorus species of LB-EPS and microbial cell. During the anaerobic-aerobic cycle, the roles of LB-EPS, TB-EPS and microbial cell in transfer and transformation of P in EBPR sludge were obviously different. LB-EPS transported and retained orthoP, and microbial cell directly anaerobically released or aerobically absorbed orthoP. Importantly, TB-EPS not only transported and retained orthoP, but also participated in biological phosphorus accumulation. The EBPR performance of sludge was closely related with the polyp in TB-EPS, which might be synthesized and decomposed by extracellular enzyme. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Systems Chemo-Biology and Transcriptomic Meta-Analysis Reveal the Molecular Roles of Bioactive Lipids in Cardiomyocyte Differentiation.

    Science.gov (United States)

    de Faria Poloni, Joice; Bonatto, Diego

    2015-09-01

    Lipids, which are essential constituents of biological membranes, play structural and functional roles in the cell. In recent years, certain lipids have been identified as regulatory signaling molecules and have been termed "bioactive lipids". Subsequently, the importance of bioactive lipids in stem cell differentiation and cardiogenesis has gained increasing recognition. Therefore, the aim of this study was to identify the biological processes underlying murine cardiac differentiation and the mechanisms by which bioactive lipids affect these processes. For this purpose, a transcriptomic meta-analysis of microarray and RNA-seq data from murine stem cells undergoing cardiogenic differentiation was performed. The differentially expressed genes identified via this meta-analysis, as well as bioactive lipids, were evaluated using systems chemo-biology tools. These data indicated that bioactive lipids are associated with the regulation of cell motility, cell adhesion, cytoskeletal rearrangement, and gene expression. Moreover, bioactive lipids integrate the signaling pathways involved in cell migration, the secretion and remodeling of extracellular matrix components, and the establishment of the cardiac phenotype. In conclusion, this study provides new insights into the contribution of bioactive lipids to the induction of cellular responses to various stimuli, which may originate from the extracellular environment and morphogens, and the manner in which this contribution directly affects murine heart morphogenesis.

  16. Histopathological And Biological Studies On The Role Of Soybean And Broad Bean AgainstRadiation Induce Damage In Rat Kidney

    Directory of Open Access Journals (Sweden)

    Hanaa Fathy Waer, **Abdel El ­ Rahman Mohamed Attia

    2002-09-01

    Full Text Available Most of the physiological and histological activities in the animal body are disturbed after exposure to ionizing radiation. These disturbances are either due to direct harmful effect of radiation on the biological systems or to the indirect effect of free radicals formed in the body after irradiation. There is growing evidence that the type of food plays an important role in the prevention of chronic diseases. The biological disturbance due to ionizing radiation makes search for ways of protecting living organisms essential for controlling the radiation hazards. Much of the world population relies on legumes, as a stable food. Legumes can affectively protect cells and tissues against damage. Our present study was conducted to investigate the hazardous effects of single dose !"#$%#&f the possible protective effect of feeding beans (broad beans and soybeans against radiation exposure. Histopathological, and biological changes of kidney function in irradiated, and bean fed animals were carried out. Animals were weighted and daily food intake was determined. The result obtained revealed that soybean is an extremely rich source of protein and fat as compared to faba bean. Radiations cause a reduction in food intake and weight gain. It causes great changes in the kidney glomeruli and collecting tubules. The recovery of the cells depend on the type of feeding so, feeding soybean gives a significant radiation protection and decreases the extent of changes induced by radiation

  17. Induced Folding Under Membrane Mimetic and Acidic Conditions Implies Undiscovered Biological Roles of Prokaryotic Ubiquitin-Like Protein Pup.

    Science.gov (United States)

    Ye, Kaiqin; Tu, Xiaoming; Zhang, Xuecheng; Shang, Qiang; Liao, Shanhui; Yu, Jigang; Zhang, Jiahai

    2016-01-01

    Ubiquitin-like proteins play important roles in diverse biological processes. In Mycobacterium tuberculosis, Pup (prokaryotic ubiquitin-like protein), a functional homologue of eukaryotic ubiquitin, interacts with the proteasome ATPase subunit Mpa to recognize and unfold substrates, and then translocate them into the proteasome core for degradation. Previous studies revealed that, Pup, an intrinsically disordered protein (IDP), adopts a helical structure upon binding to the N-terminal coiled-coil domain of Mpa, at its disordered C-terminal region. In the present study, using circular dichroism (CD), surface plasmon resonance (SPR) and nuclear magnetic resonance (NMR), we show that membrane mimetic and acidic conditions also induce Pup to adopt helical conformations. Moreover, at low pH, Pup, via both of its N- and C-terminal regions, binds to Mpa on sites from the N-terminal region in addition to the C-terminal region of the coiled-coil domain. Our results imply Pup may play undiscovered roles in some biological processes e.g. those involve in membrane.

  18. The role of energy in the emergence of biology from chemistry.

    Science.gov (United States)

    Dibrova, Daria V; Chudetsky, Michail Y; Galperin, Michael Y; Koonin, Eugene V; Mulkidjanian, Armen Y

    2012-10-01

    Any scenario of the transition from chemistry to biology should include an "energy module" because life can exist only when supported by energy flow(s). We addressed the problem of primordial energetics by combining physico-chemical considerations with phylogenomic analysis. We propose that the first replicators could use abiotically formed, exceptionally photostable activated cyclic nucleotides both as building blocks and as the main energy source. Nucleoside triphosphates could replace cyclic nucleotides as the principal energy-rich compounds at the stage of the first cells, presumably because the metal chelates of nucleoside triphosphates penetrated membranes much better than the respective metal complexes of nucleoside monophosphates. The ability to exploit natural energy flows for biogenic production of energy-rich molecules could evolve only gradually, after the emergence of sophisticated enzymes and ion-tight membranes. We argue that, in the course of evolution, sodium-dependent membrane energetics preceded the proton-based energetics which evolved independently in bacteria and archaea.

  19. Role and Function of MicroRNAs in Extracellular Vesicles in Cardiovascular Biology

    Directory of Open Access Journals (Sweden)

    Philipp Pfeifer

    2015-01-01

    Full Text Available Intercellular communication mediated by extracellular vesicles is crucial for preserving vascular integrity and in the development of cardiovascular disease. Extracellular vesicles consist of apoptotic bodies, microvesicles, and exosomes that can be found in almost every fluid compartment of the body like blood, saliva, and urine. In the recent years, a lot of reports came up suggesting that major cardiovascular and metabolic pathologies like atherogenesis, heart failure, or diabetes are highly influenced by transfer of microRNAs via extracellular vesicles leading to altered protein expression and phenotypes of recipient cells. The following review will summarize the fast developing field of intercellular signaling in cardiovascular biology by microRNA-containing extracellular vesicles.

  20. The role of socioscientific issues in biology teaching – from the perspective of teachers

    DEFF Research Database (Denmark)

    Tidemand, Sofie; Nielsen, Jan Alexis

    2016-01-01

    documented that a range of challenges hinders the uptake of socioscientific issues. In this study we investigated the interpretation and implementation of socioscientific issues among Danish biology teachers – who teach in a curriculum that, on paper, is permeated by socioscientific issues. We conducted five...... for science educators, policy-makers and curriculum designers, as we argue that key aspects of this content-centred interpretation may be a coping strategy used in order to navigate a divided curriculum.......Previous research has documented that students who engage with socioscientific issues can acquire some of the complex competences and skills typically related to scientific literacy. But an emerging field of research on science teachers’ understanding and use of socioscientific issues, has...

  1. Treatment in rheumatoid arthritis and mortality risk in clinical practice: the role of biologic agents.

    Science.gov (United States)

    Rodriguez-Rodriguez, Luis; Leon, Leticia; Ivorra-Cortes, Jose; Gómez, Alejandro; Lamas, Jose Ramon; Pato, Esperanza; Jover, Juan Ángel; Abásolo, Lydia

    2016-01-01

    To assess the mortality rate (MR) and the mortality risk of a rheumatoid arthritis (RA) inception cohort, with and without biologic agents (BAs). Other factors associated to mortality were also investigated. Retrospective longitudinal study of RA patients, attending the rheumatology outpatient clinic of a tertiary Hospital (Madrid), collected over 5 years (2000-2004), and followed from the diagnosis of RA up to the patients' death, lost to follow-up or September 2013. The dependent variable was death and the independent variable was exposure to BAs. Covariables: sociodemographic, clinical and therapy variables. MR was expressed per 1,000 patient-years with the 95% confidence interval [CI]. BA influence on MR was analysed by multivariable Cox models. Clinical and therapy variables were used in a time-dependent manner. The results are expressed in hazard ratio (HR) and [CI]. We included 576 patients and 711 courses of therapy. 19.6% were taking BA, 86% disease-modifying anti-rheumatic drugs (DMARDs) (70% on methotrexate - MTX), and 12% were untreated. There were 133 deaths during 4,981.64 patient-years at risk. The MR for BA was 12.6 [6-26], for DMARDs was 22.3 [18.4-27.1], and for those without treatment was 89.1 [61.9-128.2]. The adjusted HR for mortality in those exposed to BA versus those not exposed was 0.75 [0.32-1.71]). Other variables independently associated with mortality were: age, rheumatoid factor, hospital admissions, Health Assessment Questionnaire (HAQ), and MTX use (HR: 0.44 [0.29-0.66]). BAs and standard DMARDs are more effective in decreasing mortality compared to no therapy. Patients exposed to Bas were not associated with a significant increase or decrease in mortality when compared to patients with non-biological DMARDs. The use of MTX remains the only drug that has independently shown a beneficial effect on mortality.

  2. Structure and functions of water-membrane interfaces and their role in proto-biological evolution

    Science.gov (United States)

    Pohorille, A.; Wilson, M.; Macelroy, R. D.

    1991-01-01

    Among the most important developments in proto-biological evolution was the emergence of membrane-like structures. These are formed by spontaneous association of relatively simple amphiphilic molecules that would have been readily available in the primordial environment. The resulting interfacial regions between water and nonpolar interior of the membrane have several properties which made them uniquely suitable for promoting subsequent evolution. They can (1) selectively attract organic material and mediate its transport, (2) serve as simple catalysts for chemical reactions, and (3) promote the formation of trans-membrane electrical and chemical gradients which could provide energy sources for proto-cells. Understanding the structure of interfaces, their interactions with organic molecules and molecular mechanisms of their functions is an essential step to understanding proto-biological evolution. In our computer simulation studies, we showed that the structure of water at interfaces with nonpolar media is significantly different from that in the bulk. In particular, the average surface dipole density points from the vapor to the liquid. As a result, negative ions can approach the interface more easily than positive ions. Amphiphilic molecules composed of hydrocarbon conjugated rings and polar substituents (e.g., phenol) assume at the interface rigid orientations in which polar groups are buried in water while hydrocarbon parts are located in the nonpolar environment. These orientational differences are of special interest in connection with the ability of some of these molecules to efficiently absorb photons. Flexible molecules with polar substituents often adopt at interfaces conformations different from those in the bulk aquaeous solution and in the gas phase. As a result, in many instances both specificity and kinetics of chemical reactions in which these molecules can participate is modified by the presence of surfaces. Of special interest is the mechanism by

  3. Flexible mechanisms: the diverse roles of biological springs in vertebrate movement.

    Science.gov (United States)

    Roberts, Thomas J; Azizi, Emanuel

    2011-02-01

    The muscles that power vertebrate locomotion are associated with springy tissues, both within muscle and in connective tissue elements such as tendons. These springs share in common the same simple action: they stretch and store elastic strain energy when force is applied to them and recoil to release energy when force decays. Although this elastic action is simple, it serves a diverse set of functions, including metabolic energy conservation, amplification of muscle power output, attenuation of muscle power input, and rapid mechanical feedback that may aid in stability. In recent years, our understanding of the mechanisms and importance of biological springs in locomotion has advanced significantly, and it has been demonstrated that elastic mechanisms are essential for the effective function of the muscle motors that power movement. Here, we review some recent advances in our understanding of elastic mechanisms, with an emphasis on two proposed organizing principles. First, we review the evidence that the various functions of biological springs allow the locomotor system to operate beyond the bounds of intrinsic muscle properties, including metabolic and mechanical characteristics, as well as motor control processes. Second, we propose that an energy-based framework is useful for interpreting the diverse functions of series-elastic springs. In this framework, the direction and timing of the flow of energy between the body, the elastic element and the contracting muscle determine the function served by the elastic mechanism (e.g. energy conservation vs power amplification). We also review recent work demonstrating that structures such as tendons remodel more actively and behave more dynamically than previously assumed.

  4. BIOLOGY OF FOXM1 AND ITS EMERGING ROLE IN CANCER THERAPY

    Directory of Open Access Journals (Sweden)

    Neha Jaiswal

    2014-03-01

    Full Text Available The FOXM1 transcription factor has been implicated to play a central role in the regulation of crucial cellular activities. Evidences regarding the significance of FOXM1 in cell cycle control, genomic stability and tumorigenesis are undeniable. This has generated much interest in the field and as a result, past decade has witnessed remarkable progress in FOXM1 research addressing complexity of its function and regulation in tumorigenesis. Its proven role in carcinogenesis and its prospect as a promising therapeutic target against cancer makes it a molecule of considerable clinical interest. A thorough understanding of FOXM1 will be extremely useful in the innovation of strategies for treating and preventing cancer. Here we present a systematic literature review on FOXM1 highlighting its key functions and molecular mechanisms of association in tumorigenesis and its prospects in cancer therapy

  5. Volatile compounds of raspberry fruit: from analytical methods to biological role and sensory impact.

    Science.gov (United States)

    Aprea, Eugenio; Biasioli, Franco; Gasperi, Flavia

    2015-01-30

    Volatile compounds play a key role in the formation of the well-recognized and widely appreciated raspberry aroma. Studies on the isolation and identification of volatile compounds in raspberry fruit (Rubus idaeus L.) are reviewed with a focus on aroma-related compounds. A table is drawn up containing a comprehensive list of the volatile compounds identified so far in raspberry along with main references and quantitative data where available. Two additional tables report the glycosidic bond and enantiomeric distributions of the volatile compounds investigated up to now in raspberry fruit. Studies on the development and evolution of volatile compounds during fruit formation, ripening and senescence, and genetic and environmental influences are also reviewed. Recent investigations showing the potential role of raspberry volatile compounds in cultivar differentiation and fruit resistance to mold disease are reported as well. Finally a summary of research done so far and our vision for future research lines are reported.

  6. Volatile Compounds of Raspberry Fruit: From Analytical Methods to Biological Role and Sensory Impact

    Directory of Open Access Journals (Sweden)

    Eugenio Aprea

    2015-01-01

    Full Text Available Volatile compounds play a key role in the formation of the well-recognized and widely appreciated raspberry aroma. Studies on the isolation and identification of volatile compounds in raspberry fruit (Rubus idaeus L. are reviewed with a focus on aroma-related compounds. A table is drawn up containing a comprehensive list of the volatile compounds identified so far in raspberry along with main references and quantitative data where available. Two additional tables report the glycosidic bond and enantiomeric distributions of the volatile compounds investigated up to now in raspberry fruit. Studies on the development and evolution of volatile compounds during fruit formation, ripening and senescence, and genetic and environmental influences are also reviewed. Recent investigations showing the potential role of raspberry volatile compounds in cultivar differentiation and fruit resistance to mold disease are reported as well. Finally a summary of research done so far and our vision for future research lines are reported.

  7. The role of microbial-produced extracellular polymeric matrix in the formation and survival of biological soil crusts

    Science.gov (United States)

    Rossi, Federico; Adessi, Alessandra; De Philippis, Roberto

    2016-04-01

    Biological soil crusts (BSCs) are complex communities commonly constituting organo-mineral layers in arid and semiarid environment having a major influence on these ecosystems (Belnap and Lange, 2001). They have high tolerance towards a-biotic stresses and fluctuations in moisture, illumination, salinity and nutrients. The plasticity exhibited by BSCs is hugely contributed by the presence of the extracellular polymeric matrix (EPM) that is synthesized by crustal organisms, notably cyanobacteria and microalgae. This polysaccharidic net plays key roles in biofilm relations with the surrounding constrained environment. Notably, EPM concurs in coping with water scarcity, freezing and salt stress; increases biolayers stability against erosion, and is involved in nutrient provision (Rossi and De Philippis, 2015). We conducted several investigations in a research area located in the Inner Mongolian desert (Inner Mongolia, China) where BSCs were induced over different sites through inoculation-based techniques performed in different years. Our studies were aimed at determining the role of EPM in BSC development and survival in such a hyper-arid system. This presentation will report the results concerning the role of EPM in water capture from non-rainfall sources, water maintenance at the topsoil, and in water infiltrability, the latter being a factor with important ecological implications. In additions we investigated the role of the matrix as a source of carbon for the crustal heterotrophs. Furthermore, EPM was extracted with methods optimized in our lab, aiming at removing tightly bound fractions and loosely bound fractions from BSCs having different ages. The fractions were analyzed in terms of monosaccharidic composition, and molecular weight (MW) distribution. We show how the relative amounts of uronic acids increase in the EPM with the age of the crusts, implying advantages for the community-water relations. In addition, we observed significant differences in MW

  8. The role of transient dynamics in biological pest control: insights from a host-parasitoid community.

    Science.gov (United States)

    Kidd, David; Amarasekare, Priyanga

    2012-01-01

    1. Identifying natural enemies that can maintain pests at low abundances is a priority in biological control. Here, we show that experiments combined with models generate new insights into identifying effective control agents prior to their release in the field. Using a host-parasitoid community (the harlequin bug and its egg parasitoids) as a model system, we report three key findings. 2. The interplay between the host's self-limitation and the parasitoids' saturating functional response causes the long-term (steady-state) outcomes for pest suppression to differ from those of short-term (transient) dynamics. When the bug's self-limitation is moderately strong, the parasitoid with the higher attack rate and conversion efficiency (Ooencyrtus) achieves greater host suppression in the long term, but its longer handling time causes long periods of transient dynamics during which the bug can reach high abundances; when the bug's self-limitation is weak, host fluctuations amplify over time and Ooencyrtus fails at host suppression altogether. In contrast, the parasitoid with the lower attack rate and conversion efficiency but the shorter handling time (Trissolcus) induces only weak transient fluctuations of short duration and can maintain the host at low abundances regardless of the strength of the bug's self-limitation. 3. Release of multiple enemy species can compromise host suppression if an enemy that induces stronger transient fluctuations excludes one that induces weaker fluctuations. For instance, Ooencyrtus excludes Trissolcus despite having a longer handling time because of its higher conversion efficiency. The model correctly predicts the time to exclusion observed in experiments, suggesting that it captures the key biological features of the host-parasitoid interaction. 4. Intraspecific interference reduces long-term pest suppression but improves short-term pest control by reducing the magnitude and duration of transient fluctuations. 5. These results highlight

  9. Role of Regulatory T Cells in Pathogenesis and Biological Therapy of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Milan Buc

    2013-01-01

    Full Text Available Multiple sclerosis (MS is an inflammatory disease in which the myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms. It is caused by an autoimmune response to self-antigens in a genetically susceptible individual induced by unknown environmental factors. Principal cells of the immune system that drive the immunopathological processes are T cells, especially of TH1 and TH17 subsets. However, in recent years, it was disclosed that regulatory T cells took part in, too. Subsequently, there was endeavour to develop ways how to re-establish their physiological functions. In this review, we describe known mechanisms of action, efficacy, and side-effects of contemporary and emerging MS immunotherapeutical agents on Treg cells and other cells of the immune system involved in the immunopathogenesis of the disease. Furthermore, we discuss how laboratory immunology can offer physicians its help in the diagnosis process and decisions what kind of biological therapy should be used.

  10. Extensive cargo identification reveals distinct biological roles of the 12 importin pathways

    Science.gov (United States)

    Kimura, Makoto; Morinaka, Yuriko; Imai, Kenichiro; Kose, Shingo; Horton, Paul; Imamoto, Naoko

    2017-01-01

    Vast numbers of proteins are transported into and out of the nuclei by approximately 20 species of importin-β family nucleocytoplasmic transport receptors. However, the significance of the multiple parallel transport pathways that the receptors constitute is poorly understood because only limited numbers of cargo proteins have been reported. Here, we identified cargo proteins specific to the 12 species of human import receptors with a high-throughput method that employs stable isotope labeling with amino acids in cell culture, an in vitro reconstituted transport system, and quantitative mass spectrometry. The identified cargoes illuminated the manner of cargo allocation to the receptors. The redundancies of the receptors vary widely depending on the cargo protein. Cargoes of the same receptor are functionally related to one another, and the predominant protein groups in the cargo cohorts differ among the receptors. Thus, the receptors are linked to distinct biological processes by the nature of their cargoes. DOI: http://dx.doi.org/10.7554/eLife.21184.001 PMID:28117667

  11. Systems biology from micro-organisms to human metabolic diseases: the role of detailed kinetic models.

    Science.gov (United States)

    Bakker, Barbara M; van Eunen, Karen; Jeneson, Jeroen A L; van Riel, Natal A W; Bruggeman, Frank J; Teusink, Bas

    2010-10-01

    Human metabolic diseases are typically network diseases. This holds not only for multifactorial diseases, such as metabolic syndrome or Type 2 diabetes, but even when a single gene defect is the primary cause, where the adaptive response of the entire network determines the severity of disease. The latter may differ between individuals carrying the same mutation. Understanding the adaptive responses of human metabolism naturally requires a systems biology approach. Modelling of metabolic pathways in micro-organisms and some mammalian tissues has yielded many insights, qualitative as well as quantitative, into their control and regulation. Yet, even for a well-known pathway such as glycolysis, precise predictions of metabolite dynamics from experimentally determined enzyme kinetics have been only moderately successful. In the present review, we compare kinetic models of glycolysis in three cell types (African trypanosomes, yeast and skeletal muscle), evaluate their predictive power and identify limitations in our understanding. Although each of these models has its own merits and shortcomings, they also share common features. For example, in each case independently measured enzyme kinetic parameters were used as input. Based on these 'lessons from glycolysis', we will discuss how to make best use of kinetic computer models to advance our understanding of human metabolic diseases.

  12. Cumulus Cell Expansion, Its Role in Oocyte Biology and Perspectives of Measurement: A Review

    Directory of Open Access Journals (Sweden)

    Nevoral J.

    2015-01-01

    Full Text Available Cumulus expansion of the cumulus-oocyte complex is necessary for meiotic maturation and acquiring developmental competence. Cumulus expansion is based on extracellular matrix synthesis by cumulus cells. Hyaluronic acid is the most abundant component of this extracellular matrix. Cumulus expansion takes place during meiotic oocyte maturation under in vivo and in vitro conditions. Quantification and measurement of cumulus expansion intensity is one possible method of determining oocyte quality and optimizing conditions for in vitro cultivation. Currently, subjective methods of expanded area and more exact cumulus expansion measurement by hyaluronic acid assessment are available. Among the methods of hyaluronic acid measurement is the use of radioactively labelled synthesis precursors. Alternatively, immunological and analytical methods, including enzyme-linked immunosorbent assay (ELISA, spectrophotometry, and high-performance liquid chromatography (HPLC in UV light, could be utilized. The high sensitivity of these methods could provide a precise analysis of cumulus expansion without the use of radioisotopes. Therefore, the aim of this review is to summarize and compare available approaches of cumulus expansion measurement, respecting special biological features of expanded cumuli, and to suggest possible solutions for exact cumulus expansion analysis.

  13. The Role of Genes in Defining a Molecular Biology of PTSD

    Directory of Open Access Journals (Sweden)

    Rachel Yehuda

    2011-01-01

    Full Text Available Because environmental exposure to trauma is the sine qua non for the development of Post Traumatic Stress Disorder (PTSD, the recent focus on genetic studies has been noteworthy. The main catalyst for such studies is the observation from epidemiological studies that not all trauma survivors develop this disorder. Furthermore, neuroendocrine findings suggest pre-existing hormonal alterations that confer risk for PTSD. This paper presents the rationale for examining genetic factors in PTSD and trauma exposure, but suggests that studies of genotype may only present a limited picture of the molecular biology of this disorder. We describe the type of information that can be obtained from candidate gene and genomic studies that incorporate environmental factors in the design (i.e., gene – environment interaction and gene-environment correlation studies and studies that capitalize on the idea that environment modifies gene expression, via epigenetic or other molecular mechanisms. The examination of epigenetic mechanisms in tandem with gene expression will help refine models that explain how PTSD risk, pathophysiology, and recovery is mediated by the environment. Since inherited genetic variation may also influence the extent of epigenetic or gene expression changes resulting from the environment, such studies should optimally be followed up by studies of genotype.

  14. The Role of Model Integration in Complex Systems Modelling An Example from Cancer Biology

    CERN Document Server

    Patel, Manish

    2010-01-01

    Model integration – the process by which different modelling efforts can be brought together to simulate the target system – is a core technology in the field of Systems Biology. In the work presented here model integration was addressed directly taking cancer systems as an example. An in-depth literature review was carried out to survey the model forms and types currently being utilised. This was used to formalise the main challenges that model integration poses, namely that of paradigm (the formalism on which a model is based), focus (the real-world system the model represents) and scale. A two-tier model integration strategy, including a knowledge-driven approach to address model semantics, was developed to tackle these challenges. In the first step a novel description of models at the level of behaviour, rather than the precise mathematical or computational basis of the model, is developed by distilling a set of abstract classes and properties. These can accurately describe model behaviour and hence d...

  15. Role of regulatory T cells in pathogenesis and biological therapy of multiple sclerosis.

    Science.gov (United States)

    Buc, Milan

    2013-01-01

    Multiple sclerosis (MS) is an inflammatory disease in which the myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms. It is caused by an autoimmune response to self-antigens in a genetically susceptible individual induced by unknown environmental factors. Principal cells of the immune system that drive the immunopathological processes are T cells, especially of TH1 and TH17 subsets. However, in recent years, it was disclosed that regulatory T cells took part in, too. Subsequently, there was endeavour to develop ways how to re-establish their physiological functions. In this review, we describe known mechanisms of action, efficacy, and side-effects of contemporary and emerging MS immunotherapeutical agents on Treg cells and other cells of the immune system involved in the immunopathogenesis of the disease. Furthermore, we discuss how laboratory immunology can offer physicians its help in the diagnosis process and decisions what kind of biological therapy should be used.

  16. Disentangling the role of environmental and human pressures on biological invasions across Europe.

    Science.gov (United States)

    Pysek, Petr; Jarosík, Vojtech; Hulme, Philip E; Kühn, Ingolf; Wild, Jan; Arianoutsou, Margarita; Bacher, Sven; Chiron, Francois; Didziulis, Viktoras; Essl, Franz; Genovesi, Piero; Gherardi, Francesca; Hejda, Martin; Kark, Salit; Lambdon, Philip W; Desprez-Loustau, Marie-Laure; Nentwig, Wolfgang; Pergl, Jan; Poboljsaj, Katja; Rabitsch, Wolfgang; Roques, Alain; Roy, David B; Shirley, Susan; Solarz, Wojciech; Vilà, Montserrat; Winter, Marten

    2010-07-06

    The accelerating rates of international trade, travel, and transport in the latter half of the twentieth century have led to the progressive mixing of biota from across the world and the number of species introduced to new regions continues to increase. The importance of biogeographic, climatic, economic, and demographic factors as drivers of this trend is increasingly being realized but as yet there is no consensus regarding their relative importance. Whereas little may be done to mitigate the effects of geography and climate on invasions, a wider range of options may exist to moderate the impacts of economic and demographic drivers. Here we use the most recent data available from Europe to partition between macroecological, economic, and demographic variables the variation in alien species richness of bryophytes, fungi, vascular plants, terrestrial insects, aquatic invertebrates, fish, amphibians, reptiles, birds, and mammals. Only national wealth and human population density were statistically significant predictors in the majority of models when analyzed jointly with climate, geography, and land cover. The economic and demographic variables reflect the intensity of human activities and integrate the effect of factors that directly determine the outcome of invasion such as propagule pressure, pathways of introduction, eutrophication, and the intensity of anthropogenic disturbance. The strong influence of economic and demographic variables on the levels of invasion by alien species demonstrates that future solutions to the problem of biological invasions at a national scale lie in mitigating the negative environmental consequences of human activities that generate wealth and by promoting more sustainable population growth.

  17. Resolution of Acute Inflammation and the Role of Resolvins in Immunity, Thrombosis, and Vascular Biology.

    Science.gov (United States)

    Sansbury, Brian E; Spite, Matthew

    2016-06-24

    Acute inflammation is a host-protective response that is mounted in response to tissue injury and infection. Initiated and perpetuated by exogenous and endogenous mediators, acute inflammation must be resolved for tissue repair to proceed and for homeostasis to be restored. Resolution of inflammation is an actively regulated process governed by an array of mediators as diverse as those that initiate inflammation. Among these, resolvins have emerged as a genus of evolutionarily conserved proresolving mediators that act on specific cellular receptors to regulate leukocyte trafficking and blunt production of inflammatory mediators, while also promoting clearance of dead cells and tissue repair. Given that chronic unresolved inflammation is emerging as a central causative factor in the development of cardiovascular diseases, an understanding of the endogenous processes that govern normal resolution of acute inflammation is critical for determining why sterile maladaptive cardiovascular inflammation perpetuates. Here, we provide an overview of the process of resolution with a focus on the enzymatic biosynthesis and receptor-dependent actions of resolvins and related proresolving mediators in immunity, thrombosis, and vascular biology. We discuss how nutritional and current therapeutic approaches modulate resolution and propose that harnessing resolution concepts could potentially lead to the development of new approaches for treating chronic cardiovascular inflammation in a manner that is not host disruptive.

  18. Understanding the Role of Biology in the Global Environment: NASA'S Mission to Planet Earth

    Science.gov (United States)

    Townsend, William F.

    1996-01-01

    NASA has long used the unique perspective of space as a means of expanding our understanding of how the Earth's environment functions. In particular, the linkages between land, air, water, and life-the elements of the Earth system-are a focus for NASA's Mission to Planet Earth. This approach, called Earth system science, blends together fields like meteorology, biology, oceanography, and atmospheric science. Mission to Planet Earth uses observations from satellites, aircraft, balloons, and ground researchers as the basis for analysis of the elements of the Earth system, the interactions between those elements, and possible changes over the coming years and decades. This information is helping scientists improve our understanding of how natural processes affect us and how we might be affecting them. Such studies will yield improved weather forecasts, tools for managing agriculture and forests, information for fishermen and local planners, and, eventually, an enhanced ability to predict how the climate will change in the future. NASA has designed Mission to Planet Earth to focus on five primary themes: Land Cover and Land Use Change; Seasonal to Interannual Climate Prediction; Natural Hazards; Long-Term Climate Variability; and Atmosphere Ozone.

  19. The biological basis of human sexual orientation: is there a role for epigenetics?

    Science.gov (United States)

    Ngun, Tuck C; Vilain, Eric

    2014-01-01

    Sexual orientation is one of the largest sex differences in humans. The vast majority of the population is heterosexual, that is, they are attracted to members of the opposite sex. However, a small but significant proportion of people are bisexual or homosexual and experience attraction to members of the same sex. The origins of the phenomenon have long been the subject of scientific study. In this chapter, we will review the evidence that sexual orientation has biological underpinnings and consider the involvement of epigenetic mechanisms. We will first discuss studies that show that sexual orientation has a genetic component. These studies show that sexual orientation is more concordant in monozygotic twins than in dizygotic ones and that male sexual orientation is linked to several regions of the genome. We will then highlight findings that suggest a link between sexual orientation and epigenetic mechanisms. In particular, we will consider the case of women with congenital adrenal hyperplasia (CAH). These women were exposed to high levels of testosterone in utero and have much higher rates of nonheterosexual orientation compared to non-CAH women. Studies in animal models strongly suggest that the long-term effects of hormonal exposure (such as those experienced by CAH women) are mediated by epigenetic mechanisms. We conclude by describing a hypothetical framework that unifies genetic and epigenetic explanations of sexual orientation and the continued challenges facing sexual orientation research. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Investigation on the role of IGF-1 signal transduction in the biological radiation responses

    Energy Technology Data Exchange (ETDEWEB)

    Jung, U Hee; Jo, Sung Kee; Park, Hae Ran; Oh, Soo Jin; Cho, Eun Hee; Eom, Hyun Soo; Ju, Eun Jin

    2009-05-15

    Effects of {gamma}-irradiation on the IGF-1 related gene expressions and activations in various cell lines - Various expression patterns of IGF-1 and IGF-1R following {gamma}-irradiation were observed according to the cell lines - The increased expressions of IGF-1 and IGF-1R were observed in Balb/3T3 and NIH/3T3 cells - Among the IGF-1 downstream signaling molecules, the phosphorylated ERK5 were not changed by {gamma}-irradiation in all three examined cell lines, whereas the phosphorylated p65 were increased by {gamma} -irradiation in all cell lines. The role of IGF-1 and p38 signaling in {gamma}-irradiated mouse embryonic fibroblast (MEF) cells - In MEF cells, IGF-1 signaling molecules were decreased and p21/phosphorylated p38 were increased by {gamma}-irradiation - The experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 signaling is involved but not essential in radiation-induced cell growth arrest and senescence and that p38 MAP kinase play a important role in this cellular radiation response. The role of IGF-1 and p38 signaling in {gamma}-irradiated mouse fibroblast (NIH/3T3) cell - In NIH/3T3 cells, IGF-1 signaling molecules and p21/phosphorylated p38 were increased by {gamma} -irradiation. - However, the experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 and p38 signaling do not play a crucial role in radiation-induced cell growth arrest and senescence in NIH/3T3 cells. Effects of {gamma}-irradiation on the expressions and activations on the genes related to the IGF-1 signaling in mouse tissues - In {gamma}-irradiated mice, the increased expressions of IGF-1 and IGF-1R were observed in the lung and kidney at 2 months after irradiation, and in all the tissues examined (lung, liver and kidney) at 6 months after irradiation. - In the lung of {gamma}-irradiated mice at 6 months after irradiation, the increases of IGF-1R, phosphorylated FOXO3a, p65, p38, p21 were observed. - The

  1. Enhancing the role of veterinary vaccines reducing zoonotic diseases of humans: linking systems biology with vaccine development.

    Science.gov (United States)

    Adams, L Garry; Khare, Sangeeta; Lawhon, Sara D; Rossetti, Carlos A; Lewin, Harris A; Lipton, Mary S; Turse, Joshua E; Wylie, Dennis C; Bai, Yu; Drake, Kenneth L

    2011-09-22

    The aim of research on infectious diseases is their prevention, and brucellosis and salmonellosis as such are classic examples of worldwide zoonoses for application of a systems biology approach for enhanced rational vaccine development. When used optimally, vaccines prevent disease manifestations, reduce transmission of disease, decrease the need for pharmaceutical intervention, and improve the health and welfare of animals, as well as indirectly protecting against zoonotic diseases of people. Advances in the last decade or so using comprehensive systems biology approaches linking genomics, proteomics, bioinformatics, and biotechnology with immunology, pathogenesis and vaccine formulation and delivery are expected to enable enhanced approaches to vaccine development. The goal of this paper is to evaluate the role of computational systems biology analysis of host:pathogen interactions (the interactome) as a tool for enhanced rational design of vaccines. Systems biology is bringing a new, more robust approach to veterinary vaccine design based upon a deeper understanding of the host-pathogen interactions and its impact on the host's molecular network of the immune system. A computational systems biology method was utilized to create interactome models of the host responses to Brucella melitensis (BMEL), Mycobacterium avium paratuberculosis (MAP), Salmonella enterica Typhimurium (STM), and a Salmonella mutant (isogenic ΔsipA, sopABDE2) and linked to the basis for rational development of vaccines for brucellosis and salmonellosis as reviewed by Adams et al. and Ficht et al. [1,2]. A bovine ligated ileal loop biological model was established to capture the host gene expression response at multiple time points post infection. New methods based on Dynamic Bayesian Network (DBN) machine learning were employed to conduct a comparative pathogenicity analysis of 219 signaling and metabolic pathways and 1620 gene ontology (GO) categories that defined the host's biosignatures

  2. Enhancing the role of veterinary vaccines reducing zoonotic diseases of humans: Linking systems biology with vaccine development

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Leslie G.; Khare, Sangeeta; Lawhon, Sara D.; Rossetti, Carlos A.; Lewin, Harris A.; Lipton, Mary S.; Turse, Joshua E.; Wylie, Dennis C.; Bai, Yu; Drake, Kenneth L.

    2011-09-22

    The aim of research on infectious diseases is their prevention, and brucellosis and salmonellosis as such are classic examples of worldwide zoonoses for application of a systems biology approach for enhanced rational vaccine development. When used optimally, vaccines prevent disease manifestations, reduce transmission of disease, decrease the need for pharmaceutical intervention, and improve the health and welfare of animals, as well as indirectly protecting against zoonotic diseases of people. Advances in the last decade or so using comprehensive systems biology approaches linking genomics, proteomics, bioinformatics, and biotechnology with immunology, pathogenesis and vaccine formulation and delivery are expected to enable enhanced approaches to vaccine development. The goal of this paper is to evaluate the role of computational systems biology analysis of host:pathogen interactions (the interactome) as a tool for enhanced rational design of vaccines. Systems biology is bringing a new, more robust approach to veterinary vaccine design based upon a deeper understanding of the host pathogen interactions and its impact on the host's molecular network of the immune system. A computational systems biology method was utilized to create interactome models of the host responses to Brucella melitensis (BMEL), Mycobacterium avium paratuberculosis (MAP), Salmonella enterica Typhimurium (STM), and a Salmonella mutant (isogenic *sipA, sopABDE2) and linked to the basis for rational development of vaccines for brucellosis and salmonellosis as reviewed by Adams et al. and Ficht et al. [1,2]. A bovine ligated ileal loop biological model was established to capture the host gene expression response at multiple time points post infection. New methods based on Dynamic Bayesian Network (DBN) machine learning were employed to conduct a comparative pathogenicity analysis of 219 signaling and metabolic pathways and 1620 gene ontology (GO) categories that defined the host

  3. Transcription factor co-repressors in cancer biology: roles and targeting.

    Science.gov (United States)

    Battaglia, Sebastiano; Maguire, Orla; Campbell, Moray J

    2010-06-01

    Normal transcription displays a high degree of flexibility over the choice, timing and magnitude of mRNA expression levels that tend to oscillate and cycle. These processes allow for combinatorial actions, feedback control and fine-tuning. A central role has emerged for the transcriptional co-repressor proteins such as NCOR1, NCOR2/SMRT, CoREST and CTBPs, to control the actions of many transcriptional factors, in large part, by recruitment and activation of a range of chromatin remodeling enzymes. Thus, co-repressors and chromatin remodeling factors are recruited to transcription factors at specific promoter/enhancer regions and execute changes in the chromatin structure. The specificity of this recruitment is controlled in a spatial-temporal manner. By playing a central role in transcriptional control, as they move and target transcription factors, co-repressors act as a key driver in the epigenetic economy of the nucleus. Co-repressor functions are selectively distorted in malignancy, by both loss and gain of function and contribute to the generation of transcriptional rigidity. Features of transcriptional rigidity apparent in cancer cells include the distorted signaling of nuclear receptors and the WNTs/beta-catenin axis. Understanding and predicting the consequences of altered co-repressor expression patterns in cancer cells has diagnostic and prognostic significance, and also have the capacity to be targeted through selective epigenetic therapies.

  4. Oxidoreductases and cellulases in lichens: possible roles in lichen biology and soil organic matter turnover.

    Science.gov (United States)

    Beckett, Richard P; Zavarzina, Anna G; Liers, Christiane

    2013-06-01

    Lichens are symbiotic associations of a fungus (usually an Ascomycete) with green algae and/or a cyanobacterium. They dominate on 8 % of the world's land surface, mainly in Arctic and Antarctic regions, tundra, high mountain elevations and as components of dryland crusts. In many ecosystems, lichens are the pioneers on the bare rock or soil following disturbance, presumably because of their tolerance to desiccation and high temperature. Lichens have long been recognized as agents of mineral weathering and fine-earth stabilization. Being dominant biomass producers in extreme environments they contribute to primary accumulation of soil organic matter. However, biochemical role of lichens in soil processes is unknown. Our recent research has demonstrated that Peltigeralean lichens contain redox enzymes which in free-living fungi participate in lignocellulose degradation and humification. Thus lichen enzymes may catalyse formation and degradation of soil organic matter, particularly in high-stress communities dominated by lower plants. In the present review we synthesize recently published data on lichen phenol oxidases, peroxidases, and cellulases and discuss their possible roles in lichen physiology and soil organic matter transformations.

  5. Sweeten PAMPs: Role of sugar complexed PAMPs in innate immunity and vaccine biology

    Directory of Open Access Journals (Sweden)

    Ranjeet Singh Mahla

    2013-09-01

    Full Text Available Innate sensors play a critical role in the early innate immune responses to invading pathogens through sensing of diverse biochemical signatures also known as pathogen associated molecular patterns (PAMPs. These biochemical signatures primarily consist of a major family of biomolecules such as proteins, lipids, nitrogen bases, and sugar and its complexes, which are distinct from host molecules and exclusively expressed in pathogens and essential to their survival. The family of sensors known as pattern recognition receptors (PRRs are germ-line encoded, evolutionarily conserved molecules and consist of Toll-like receptors (TLRs, RIG-I-like receptors (RLRs, NOD-like receptors (NLRs, C-type lectin-like receptors (CLRs, and DNA sensors. Sensing of PAMP by PRR initiates the cascade of signaling leading to the activation of transcription factors, such as NF-κB and interferon regulatory factors (IRFs, resulting in a variety of cellular responses, including the production of interferons (IFNs and pro-inflammatory cytokines. In this review, we discuss sensing of different types of glycosylated PAMPs such as -glucan (a polymeric sugar or lipopolysaccharides, nucleic acid, and so on (sugar complex PAMPs by different families of sensors, its role in pathogenesis, and its application in development of potential vaccine and vaccine adjuvants.

  6. Micro-managing the circadian clock: The role of microRNAs in biological timekeeping.

    Science.gov (United States)

    Mehta, Neel; Cheng, Hai-Ying M

    2013-10-09

    Evolved under the selective pressures of a 24-h world, circadian timekeeping mechanisms are present in virtually all living organisms to coordinate daily rhythms in physiology and behavior. Until recently, the circadian clock was modeled as simple, interlocked transcription-translation feedback loops driving rhythms in gene expression of a handful of core clock genes. However, it has become evident that circadian clock regulation is immensely more complex than once thought and involves posttranscriptional, translational and posttranslational mechanisms. In particular, there has been a growing awareness of the vital role played by microRNAs (miRNAs) in regulating various aspects of circadian clock function. In this review, we will summarize our current knowledge of miRNA-dependent regulation of the circadian timing system in multiple organisms, including flies, mammals and higher plants. We will also discuss future perspectives for research on the role of miRNAs and noncoding RNAs in circadian regulation of health and disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Understanding Biological Roles of Venoms Among the Caenophidia: The Importance of Rear-Fanged Snakes.

    Science.gov (United States)

    Mackessy, Stephen P; Saviola, Anthony J

    2016-11-01

    Snake venoms represent an adaptive trophic response to the challenges confronting a limbless predator for overcoming combative prey, and this chemical means of subduing prey shows several dominant phenotypes. Many front-fanged snakes, particularly vipers, feed on various vertebrate and invertebrate prey species, and some of their venom components (e.g., metalloproteinases, cobratoxin) appear to have been selected for "broad-brush" incapacitation of different prey taxa. Using proteomic and genomic techniques, the compositional diversity of front-fanged snakes is becoming well characterized; however, this is not the case for most rear-fanged colubroid snakes. Because these species consume a high diversity of prey, and because venoms are primarily a trophic adaptation, important clues for understanding specific selective pressures favoring venom component composition will be found among rear-fanged snake venoms. Rear-fanged snakes typically (but not always) produce venoms with lower complexity than front-fanged snakes, and there are even fewer dominant (and, arguably, biologically most relevant) venom protein families. We have demonstrated taxon-specific toxic effects, where lizards and birds show high susceptibility while mammals are largely unaffected, for both Old World and New World rear-fanged snakes, strongly indicating a causal link between toxin evolution and prey preference. New data are presented on myotoxin a, showing that the extremely rapid paralysis induced by this rattlesnake toxin is specific for rodents, and that myotoxin a is ineffectual against lizards. Relatively few rear-fanged snake venoms have been characterized, and basic natural history data are largely lacking, but directed sampling of specialized species indicates that novel compounds are likely among these specialists, particularly among those species feeding on invertebrate prey such as scorpions and centipedes. Because many of the more than 2200 species of colubroid snakes are rear

  8. Model-based analysis of the role of biological, hydrological and geochemical factors affecting uranium bioremediation.

    Science.gov (United States)

    Zhao, Jiao; Scheibe, Timothy D; Mahadevan, R

    2011-07-01

    Uranium contamination is a serious concern at several sites motivating the development of novel treatment strategies such as the Geobacter-mediated reductive immobilization of uranium. However, this bioremediation strategy has not yet been optimized for the sustained uranium removal. While several reactive-transport models have been developed to represent Geobacter-mediated bioremediation of uranium, these models often lack the detailed quantitative description of the microbial process (e.g., biomass build-up in both groundwater and sediments, electron transport system, etc.) and the interaction between biogeochemical and hydrological process. In this study, a novel multi-scale model was developed by integrating our recent model on electron capacitance of Geobacter (Zhao et al., 2010) with a comprehensive simulator of coupled fluid flow, hydrologic transport, heat transfer, and biogeochemical reactions. This mechanistic reactive-transport model accurately reproduces the experimental data for the bioremediation of uranium with acetate amendment. We subsequently performed global sensitivity analysis with the reactive-transport model in order to identify the main sources of prediction uncertainty caused by synergistic effects of biological, geochemical, and hydrological processes. The proposed approach successfully captured significant contributing factors across time and space, thereby improving the structure and parameterization of the comprehensive reactive-transport model. The global sensitivity analysis also provides a potentially useful tool to evaluate uranium bioremediation strategy. The simulations suggest that under difficult environments (e.g., highly contaminated with U(VI) at a high migration rate of solutes), the efficiency of uranium removal can be improved by adding Geobacter species to the contaminated site (bioaugmentation) in conjunction with the addition of electron donor (biostimulation). The simulations also highlight the interactive effect of

  9. Wine as a biological fluid: history, production, and role in disease prevention.

    Science.gov (United States)

    Soleas, G J; Diamandis, E P; Goldberg, D M

    1997-01-01

    Wine has been part of human culture for 6,000 years, serving dietary and socio-religious functions. Its production takes place on every continent, and its chemical composition is profoundly influenced by enological techniques, the grape cultivar from which it originates, and climatic factors. In addition to ethanol, which in moderate consumption can reduce mortality from coronary heart disease by increasing high-density lipoprotein cholesterol and inhibiting platelet aggregation, wine (especially red wine) contains a range of polyphenols that have desirable biological properties. These include the phenolic acids (p-coumaric, cinnamic, caffeic, gentisic, ferulic, and vanillic acids), trihydroxy stilbenes (resveratrol and polydatin), and flavonoids (catechin, epicatechin, and quercetin). They are synthesized by a common pathway from phenylalanine involving polyketide condensation reactions. Metabolic regulation is provided by competition between resveratrol synthase and chalcone synthase for a common precursor pool of acyl-CoA derivatives. Polymeric aggregation gives rise, in turn to the viniferins (potent antifungal agents) and procyanidins (strong antioxidants that also inhibit platelet aggregation). The antioxidant effects of red wine and of its major polyphenols have been demonstrated in many experimental systems spanning the range from in vitro studies (human low-density lipoprotein, liposomes, macrophages, cultured cells) to investigations in healthy human subjects. Several of these compounds (notably catechin, quercetin, and resveratrol) promote nitric oxide production by vascular endothelium; inhibit the synthesis of thromboxane in platelets and leukotriene in neutrophils, modulate the synthesis and secretion of lipoproteins in whole animals and human cell lines, and arrest tumour growth as well as inhibit carcinogenesis in different experimental models. Target mechanisms to account for these effects include inhibition of phospholipase A2 and cyclo

  10. Multiple Roles of the Y Chromosome in the Biology of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Roberto Piergentili

    2010-01-01

    Full Text Available The X and Y chromosomes of Drosophila melanogaster were the first examples of chromosomes associated with genetic information. Thanks to the serendipitous discovery of a male with white eyes in 1910, T.H. Morgan was able to associate the X chromosome of the fruit fly with a phenotypic character (the eye color for the first time. A few years later, his student, C.B. Bridges, demonstrated that X0 males, although phenotypically normal, are completely sterile. This means that the X chromosome, like the autosomes, harbors genes that control several phenotypic traits, while the Y chromosome is important for male fertility only. Notwithstanding its long history – almost 100 years in terms of genetic studies – most of the features of the Y chromosome are still a mystery. This is due to the intrinsic nature of this genetic element, namely, (1 its molecular composition (mainly transposable elements and satellite DNA, (2 its genetic inertia (lack of recombination due to its heterochromatic nature, (3 the absence of homology with the X (with the only exception of the nucleolar organizer, (4 the lack of visible phenotypes when it is missing (indeed, except for their sterility, X0 flies are normal males, and (5 its low density as for protein-coding sequences (to date, only 13 genes out of approximately 14,000 have been mapped on this chromosome in D. melanogaster, i.e., ~0.1% of the total. Nonetheless, a more accurate analysis reveals that this chromosome can influence several complex phenotypes: (1 it has a role in the fertility of both sexes and viability of males when over-represented; (2 it can unbalance the intracellular nucleotide pool; (3 it can interfere with the gene expression either by recruiting proteins involved in chromatin remodeling (PEV or, to a higher extent, by influencing the expression of up to 1,000 different genes, probably by changing the availability of transcription factors; (4 it plays a major role (up to 50% in the resistance

  11. Role of ATP as a Key Signaling Molecule Mediating Radiation-Induced Biological Effects.

    Science.gov (United States)

    Kojima, Shuji; Ohshima, Yasuhiro; Nakatsukasa, Hiroko; Tsukimoto, Mitsutoshi

    2017-01-01

    Adenosine triphosphate (ATP) serves as a signaling molecule for adaptive responses to a variety of cytotoxic agents and plays an important role in mediating the radiation stress-induced responses that serve to mitigate or repair the injurious effects of γ radiation on the body. Indeed, low doses of radiation may have a net beneficial effect by activating a variety of protective mechanisms, including antitumor immune responses. On the other hand, ATP signaling may be involved in the radiation resistance of cancer cells. Here, focusing on our previous work, we review the evidence that low-dose γ irradiation (0.25-0.5 Gy) induces release of extracellular ATP, and that the released ATP mediates multiple radiation-induced responses, including increased intracellular antioxidant synthesis, cell-mediated immune responses, induction of DNA damage repair systems, and differentiation of regulatory T cells.

  12. Role of ATP as a Key Signaling Molecule Mediating Radiation-Induced Biological Effects

    Directory of Open Access Journals (Sweden)

    Shuji Kojima

    2017-02-01

    Full Text Available Adenosine triphosphate (ATP serves as a signaling molecule for adaptive responses to a variety of cytotoxic agents and plays an important role in mediating the radiation stress-induced responses that serve to mitigate or repair the injurious effects of γ radiation on the body. Indeed, low doses of radiation may have a net beneficial effect by activating a variety of protective mechanisms, including antitumor immune responses. On the other hand, ATP signaling may be involved in the radiation resistance of cancer cells. Here, focusing on our previous work, we review the evidence that low-dose γ irradiation (0.25-0.5 Gy induces release of extracellular ATP, and that the released ATP mediates multiple radiation-induced responses, including increased intracellular antioxidant synthesis, cell-mediated immune responses, induction of DNA damage repair systems, and differentiation of regulatory T cells.

  13. Role of ATP as a Key Signaling Molecule Mediating Radiation-Induced Biological Effects

    Science.gov (United States)

    Ohshima, Yasuhiro; Nakatsukasa, Hiroko; Tsukimoto, Mitsutoshi

    2017-01-01

    Adenosine triphosphate (ATP) serves as a signaling molecule for adaptive responses to a variety of cytotoxic agents and plays an important role in mediating the radiation stress-induced responses that serve to mitigate or repair the injurious effects of γ radiation on the body. Indeed, low doses of radiation may have a net beneficial effect by activating a variety of protective mechanisms, including antitumor immune responses. On the other hand, ATP signaling may be involved in the radiation resistance of cancer cells. Here, focusing on our previous work, we review the evidence that low-dose γ irradiation (0.25-0.5 Gy) induces release of extracellular ATP, and that the released ATP mediates multiple radiation-induced responses, including increased intracellular antioxidant synthesis, cell-mediated immune responses, induction of DNA damage repair systems, and differentiation of regulatory T cells.

  14. Role of nitrification in the biodegradation of selected artificial sweetening agents in biological wastewater treatment process.

    Science.gov (United States)

    Tran, N H; Nguyen, V T; Urase, T; Ngo, H H

    2014-06-01

    The biodegradation of the six artificial sweetening agents including acesulfame (ACE), aspartame (ASP), cyclamate (CYC), neohesperidindihydrochalcone (NHDC), saccharin (SAC), and sucralose (SUC) by nitrifying activated sludge was first examined. Experimental results showed that ASP and NHDC were the most easily degradable compounds even in the control tests. CYC and SAC were efficiently biodegraded by the nitrifying activated sludge, whereas ACE and SUC were poorly removed. However, the biodegradation efficiencies of the ASs were increased with the increase in initial ammonium concentrations in the bioreactors. The association between nitrification and co-metabolic degradation was investigated and a linear relationship between nitrification rate and co-metabolic biodegradation rate was observed for the target artificial sweeteners (ASs). The contribution of heterotrophic microorganisms and autotrophic ammonia oxidizers in biodegradation of the ASs was elucidated, of which autotrophic ammonia oxidizers played an important role in the biodegradation of the ASs, particularly with regards to ACE and SUC.

  15. Review paper: Role of aluminum in glass-ionomer dental cements and its biological effects.

    Science.gov (United States)

    Nicholson, John W; Czarnecka, Beata

    2009-11-01

    The role of aluminum in glass-ionomers and resin-modified glass-ionomers for dentistry is reviewed. Aluminum is included in the glass component of these materials in the form of Al(2)O(3) to confer basicity on the glass and enable the glass to take part in the acid-base setting reactions. Results of studies of these reactions by FTIR and magic-angle spinning (MAS)-NMR spectroscopy are reported and the role of aluminum is discussed in detail. Aluminum has been shown to be present in the glasses in predominantly 4-coordination, as well as 5- and 6-coordination, and during setting a proportion of this is converted to 6-coordinate species within the matrix of the cement. Despite this, mature cements may contain detectable amounts of both 4- and 5-coordinate aluminum. Aluminum has been found to be leached from glass-ionomer cements, with greater amounts being released under acidic conditions. It may be associated with fluoride, with which it is known to complex strongly. Aluminum that enters the body via the gastro-intestinal tract is mainly excreted, and only about 1% ingested aluminum crosses the gut wall. Calculation shows that, if a glass-ionomer filling dissolved completely over 5 years, it would add only an extra 0.5% of the recommended maximum intake of aluminum to an adult patient. This leads to the conclusion that the release of aluminum from either type of glass-ionomer cement in the mouth poses a negligible health hazard.

  16. Role of surface charge in determining the biological effects of CdSe/ZnS quantum dots

    Directory of Open Access Journals (Sweden)

    Liu QQ

    2015-11-01

    Full Text Available Qiangqiang Liu,1,* Hongxia Li,1,* Qiyue Xia,1 Ying Liu,1 Kai Xiao,1,2 1National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, Collaborative Innovation Center for Biotherapy, West China Hospital, 2Laboratory of Non-Human Primate Disease Model Research, State Key Laboratory of Biotherapy, Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, People’s Republic of China *These authors contributed equally to this work Abstract: The growing potential of quantum dots (QDs in biomedical applications has provoked the urgent need to thoroughly address their interaction with biological systems. However, only limited studies have been performed to explore the effects of surface charge on the biological behaviors of QDs. In the present study, three commercially available QDs with different surface coatings were used to systematically evaluate the effects of surface charge on the cellular uptake, cytotoxicity, and in vivo biodistribution of QDs. Our results demonstrated that charged QDs entered both cancer cells and macrophages more efficiently than neutral ones, while negative QDs internalized mostly. Upon entry into cells, QDs were localized in different subcellular compartments (eg, cytoplasm and lysosomes depending on the surface charge. Interestingly, inconsistent with the result of internalization, positive QDs but not negative QDs exhibited severe cytotoxicity, which was likely due to their disruption of cell membrane integrity, and production of reactive oxygen species. Biodistribution studies demonstrated that negative and neutral QDs preferentially distributed in the liver and the spleen, whereas positive QDs mainly deposited in the kidney with obvious uptake in the brain. In general, surface charge plays crucial roles in determining the biological interactions of QDs. Keywords: cellular uptake, uptake pathways, intracellular distribution, reactive oxygen species

  17. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease.

    Science.gov (United States)

    Plaitakis, Andreas; Kalef-Ezra, Ester; Kotzamani, Dimitra; Zaganas, Ioannis; Spanaki, Cleanthe

    2017-02-08

    Glutamate dehydrogenase (GDH) is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P)⁺ to NAD(P)H. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate), lipid biosynthesis (via oxidative generation of citrate), and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human) that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1) is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH) in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth. In

  18. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease

    Science.gov (United States)

    Plaitakis, Andreas; Kalef-Ezra, Ester; Kotzamani, Dimitra; Zaganas, Ioannis; Spanaki, Cleanthe

    2017-01-01

    Glutamate dehydrogenase (GDH) is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P)+ to NAD(P)H. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate), lipid biosynthesis (via oxidative generation of citrate), and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human) that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1) is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH) in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth. In

  19. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease

    Directory of Open Access Journals (Sweden)

    Andreas Plaitakis

    2017-02-01

    Full Text Available Glutamate dehydrogenase (GDH is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P+ to NAD(PH. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate, lipid biosynthesis (via oxidative generation of citrate, and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1 is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth

  20. Diversification and coevolution in brood pollination mutualisms: Windows into the role of biotic interactions in generating biological diversity.

    Science.gov (United States)

    Hembry, David H; Althoff, David M

    2016-10-01

    Brood pollination mutualisms-interactions in which specialized insects are both the pollinators (as adults) and seed predators (as larvae) of their host plants-have been influential study systems for coevolutionary biology. These mutualisms include those between figs and fig wasps, yuccas and yucca moths, leafflowers and leafflower moths, globeflowers and globeflower flies, Silene plants and Hadena and Perizoma moths, saxifrages and Greya moths, and senita cacti and senita moths. The high reciprocal diversity and species-specificity of some of these mutualisms have been cited as evidence that coevolution between plants and pollinators drives their mutual diversification. However, the mechanisms by which these mutualisms diversify have received less attention. In this paper, we review key hypotheses about how these mutualisms diversify and what role coevolution between plants and pollinators may play in this process. We find that most species-rich brood pollination mutualisms show significant phylogenetic congruence at high taxonomic scales, but there is limited evidence for the processes of both cospeciation and duplication, and there are no unambiguous examples known of strict-sense contemporaneous cospeciation. Allopatric speciation appears important across multiple systems, particularly in the insects. Host-shifts appear to be common, and widespread host-shifts by pollinators may displace other pollinator lineages. There is relatively little evidence for a "coevolution through cospeciation" model or that coevolution promotes speciation in these systems. Although we have made great progress in understanding the mechanisms by which brood pollination mutualisms diversify, many opportunities remain to use these intriguing symbioses to understand the role of biotic interactions in generating biological diversity. © 2016 Botanical Society of America.

  1. Regression modeling of the North East Atlantic Spring Bloom suggests previously unrecognized biological roles for V and Mo

    Directory of Open Access Journals (Sweden)

    Nick J Klein

    2013-03-01

    Full Text Available In order to identify the biogeochemical parameters controlling pCO2, total chlorophyll a, and dimethylsulfide (DMS concentrations during the North East Atlantic Spring Bloom (NASB, we used previously unpublished particulate and dissolved elemental concentrations to construct several linear regression models; first by hypothesis-testing, and then with exhaustive stepwise linear regression followed by leave-one-out cross-validation. The field data was obtained along a latitudinal transect from the Azores Islands to the North Atlantic, and best-fit models (determined by lowest predictive error of up to three variables are presented. Total chlorophyll a is predicted best by biomass (POC, PON parameters and by pigments characteristic of picophytoplankton for the southern section of the sampling transect (from the Azores to the Rockhall-Hatton Plateau and coccolithophores in the northern portion (from the Rockhall-Hatton Plateau to the Denmark Strait. Both the pCO2 and DMS models included variables traditionally associated with the development of the NASB such as mixed-layer depth and with Fe, Si and P-deplete conditions (dissolved Fe, dissolved and biogenic silica, dissolved PO43-. However, the regressions for pCO2 and DMS also include intracellular V and Mo concentrations, respectively. Mo is involved in DMS production as a cofactor in dimethylsulfoxide reductase. No significant biological role for V has yet been determined, although intracellular V is significantly correlated (p-value < 0.05 with biogenic silica (R2 = 0.72 and total chlorophyll a (R2 = 0.49 while the same is not true for its biogeochemical analogue Mo, suggesting active uptake of V by phytoplankton. Our statistical analysis suggests these two lesser-studied metals may play more important roles in bloom dynamics than previously thought, and highlights a need for studies focused on determining their potential biological requirements and cell quotas.

  2. Intestinal alkaline phosphatase: multiple biological roles in maintenance of intestinal homeostasis and modulation by diet.

    Science.gov (United States)

    Lallès, Jean-Paul

    2010-06-01

    The diverse nature of intestinal alkaline phosphatase (IAP) functions has remained elusive, and it is only recently that four additional major functions of IAP have been revealed. The present review analyzes the earlier literature on the dietary factors modulating IAP activity in light of these new findings. IAP regulates lipid absorption across the apical membrane of enterocytes, participates in the regulation of bicarbonate secretion and of duodenal surface pH, limits bacterial transepithelial passage, and finally controls bacterial endotoxin-induced inflammation by dephosphorylation, thus detoxifying intestinal lipopolysaccharide. Many dietary components, including fat, protein, and carbohydrate, modulate IAP expression or activity and may be combined to sustain a high level of IAP activity. In conclusion, IAP has a pivotal role in intestinal homeostasis and its activity could be increased through the diet. This is especially true in pathological situations (e.g., inflammatory bowel diseases) in which the involvement of commensal bacteria is suspected and when intestinal AP is too low to detoxify a sufficient amount of bacterial lipopolysaccharide.

  3. Sphingomyelin in High-Density Lipoproteins: Structural Role and Biological Function

    Directory of Open Access Journals (Sweden)

    Jesús Osada

    2013-04-01

    Full Text Available High-density lipoprotein (HDL levels are an inverse risk factor for cardiovascular diseases, and sphingomyelin (SM is the second most abundant phospholipid component and the major sphingolipid in HDL. Considering the marked presence of SM, the present review has focused on the current knowledge about this phospholipid by addressing its variable distribution among HDL lipoparticles, how they acquire this phospholipid, and the important role that SM plays in regulating their fluidity and cholesterol efflux from different cells. In addition, plasma enzymes involved in HDL metabolism such as lecithin–cholesterol acyltransferase or phospholipid transfer protein are inhibited by HDL SM content. Likewise, HDL SM levels are influenced by dietary maneuvers (source of protein or fat, drugs (statins or diuretics and modified in diseases such as diabetes, renal failure or Niemann–Pick disease. Furthermore, increased levels of HDL SM have been shown to be an inverse risk factor for coronary heart disease. The complexity of SM species, described using new lipidomic methodologies, and their distribution in different HDL particles under many experimental conditions are promising avenues for further research in the future.

  4. The Signaling Role of CD40 Ligand in Platelet Biology and in Platelet Component Transfusion

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    Chaker Aoui

    2014-12-01

    Full Text Available The CD40 ligand (CD40L is a transmembrane molecule of crucial interest in cell signaling in innate and adaptive immunity. It is expressed by a variety of cells, but mainly by activated T-lymphocytes and platelets. CD40L may be cleaved into a soluble form (sCD40L that has a cytokine-like activity. Both forms bind to several receptors, including CD40. This interaction is necessary for the antigen specific immune response. Furthermore, CD40L and sCD40L are involved in inflammation and a panoply of immune related and vascular pathologies. Soluble CD40L is primarily produced by platelets after activation, degranulation and cleavage, which may present a problem for transfusion. Soluble CD40L is involved in adverse transfusion events including transfusion related acute lung injury (TRALI. Although platelet storage designed for transfusion occurs in sterile conditions, platelets are activated and release sCD40L without known agonists. Recently, proteomic studies identified signaling pathways activated in platelet concentrates. Soluble CD40L is a good candidate for platelet activation in an auto-amplification loop. In this review, we describe the immunomodulatory role of CD40L in physiological and pathological conditions. We will focus on the main signaling pathways activated by CD40L after binding to its different receptors.

  5. Macrophage biology plays a central role during ionizing radiation-elicited tumor response

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    Qiuji Wu

    2017-08-01

    Full Text Available Radiation therapy is one of the major therapeutic modalities for most solid tumors. The anti-tumor effect of radiation therapy consists of the direct tumor cell killing, as well as the modulation of tumor microenvironment and the activation of immune response against tumors. Radiation therapy has been shown to promote immunogenic cells death, activate dendritic cells and enhance tumor antigen presentation and anti-tumor T cell activation. Radiation therapy also programs innate immune cells such as macrophages that leads to either radiosensitization or radioresistance, according to different tumors and different radiation regimen studied. The mechanisms underlying radiation-induced macrophage activation remain largely elusive. Various molecular players such as NF-κB, MAPKs, p53, reactive oxygen species, inflammasomes have been involved in these processes. The skewing to a pro-inflammatory phenotype thus results in the activation of anti-tumor immune response and enhanced radiotherapy effect. Therefore, a comprehensive understanding of the mechanism of radiation-induced macrophage activation and its role in tumor response to radiation therapy is crucial for the development of new therapeutic strategies to enhance radiation therapy efficacy.

  6. The Role of microRNAs in the Biology of Rare Diseases

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    Domenica Taruscio

    2011-10-01

    Full Text Available Rare diseases (RD are characterized by low prevalence and affect not more than five individuals per 10,000 in the European population; they are a large and heterogeneous group of disorders including more than 7,000 conditions and often involve all organs and tissues, with several clinical subtypes within the same disease. Very often information concerning either diagnosis and/or prognosis on many RD is insufficient. microRNAs are a class of small non-coding RNAs that regulate gene expression at the posttranscriptional level by either degrading or blocking translation of messenger RNA targets. Recently, microRNA expression patterns of body fluids underscored their potential as noninvasive biomarkers for various diseases. The role of microRNAs as potential biomarkers has become particularly attractive. The identification of disease-related microRNAs is essential for understanding the pathogenesis of diseases at the molecular level, and is critical for designing specific molecular tools for diagnosis, treatment and prevention. Computational analysis of microRNA-disease associations is an important complementary means for prioritizing microRNAs for further experimental examination. In this article, we explored the added value of miRs as biomarkers in a selected panel of RD hitting different tissues/systems at different life stages, but sharing the need of better biomarkers for diagnostic and prognostic purposes.

  7. Systems biology analysis reveals role of MDM2 in diabetic nephropathy

    Science.gov (United States)

    Saito, Rintaro; Rocanin-Arjo, Anaïs; You, Young-Hyun; Darshi, Manjula; Van Espen, Benjamin; Miyamoto, Satoshi; Pham, Jessica; Pu, Minya; Romoli, Simone; Natarajan, Loki; Ju, Wenjun; Kretzler, Matthias; Nelson, Robert; Ono, Keiichiro; Thomasova, Dana; Mulay, Shrikant R.; Ideker, Trey; D’Agati, Vivette; Beyret, Ergin; Belmonte, Juan Carlos Izpisua; Anders, Hans Joachim

    2016-01-01

    To derive new insights in diabetic complications, we integrated publicly available human protein-protein interaction (PPI) networks with global metabolic networks using metabolomic data from patients with diabetic nephropathy. We focused on the participating proteins in the network that were computationally predicted to connect the urine metabolites. MDM2 had the highest significant number of PPI connections. As validation, significant downregulation of MDM2 gene expression was found in both glomerular and tubulointerstitial compartments of kidney biopsy tissue from 2 independent cohorts of patients with diabetic nephropathy. In diabetic mice, chemical inhibition of MDM2 with Nutlin-3a led to reduction in the number of podocytes, increased blood urea nitrogen, and increased mortality. Addition of Nutlin-3a decreased WT1+ cells in embryonic kidneys. Both podocyte- and tubule-specific MDM2-knockout mice exhibited severe glomerular and tubular dysfunction, respectively. Interestingly, the only 2 metabolites that were reduced in both podocyte and tubule-specific MDM2-knockout mice were 3-methylcrotonylglycine and uracil, both of which were also reduced in human diabetic kidney disease. Thus, our bioinformatics tool combined with multi-omics studies identified an important functional role for MDM2 in glomeruli and tubules of the diabetic nephropathic kidney and links MDM2 to a reduction in 2 key metabolite biomarkers. PMID:27777973

  8. Overview on the Role of Advance Genomics in Conservation Biology of Endangered Species.

    Science.gov (United States)

    Khan, Suliman; Nabi, Ghulam; Ullah, Muhammad Wajid; Yousaf, Muhammad; Manan, Sehrish; Siddique, Rabeea; Hou, Hongwei

    2016-01-01

    In the recent era, due to tremendous advancement in industrialization, pollution and other anthropogenic activities have created a serious scenario for biota survival. It has been reported that present biota is entering a "sixth" mass extinction, because of chronic exposure to anthropogenic activities. Various ex situ and in situ measures have been adopted for conservation of threatened and endangered plants and animal species; however, these have been limited due to various discrepancies associated with them. Current advancement in molecular technologies, especially, genomics, is playing a very crucial role in biodiversity conservation. Advance genomics helps in identifying the segments of genome responsible for adaptation. It can also improve our understanding about microevolution through a better understanding of selection, mutation, assertive matting, and recombination. Advance genomics helps in identifying genes that are essential for fitness and ultimately for developing modern and fast monitoring tools for endangered biodiversity. This review article focuses on the applications of advanced genomics mainly demographic, adaptive genetic variations, inbreeding, hybridization and introgression, and disease susceptibilities, in the conservation of threatened biota. In short, it provides the fundamentals for novice readers and advancement in genomics for the experts working for the conservation of endangered plant and animal species.

  9. Biology and Role of Aedes albopictus (Skuse 1894 as Vector of Diseases

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    Hasan Boesri

    2011-12-01

    Full Text Available Behavior of the mosquito Aedes albopictus is generally res ting outside the home with the brood in a natural or artificial containers protected from sunlight. Human biting activity between the hours of9:00 to 11:00 and between the hours of 17:00 to 18:00 inside and outside the home. The period of rest after sucking the blood 4-5 days and is ready to lie. Habitat or the environment that most coveted of th is mosquito is a forest or gar­den with temperatures of 24-30 0 C. eggs hatch after 4-5 days with a temperature of 24-30 0 C, the eggs usually form elus ters of 49-60 eggs Larvae and pupae usually found in contain­ers, pieces of bambo containing water. The period of the larvae to adults between 20-25 days. The spread of Ae albopictus mosquitoes from Africa, India, Pakistan, Sri Lanka, Thai­land, Malaysia, Vietnam, Papua New Guinea, northern Australia, and Indonesia. Role in disease transmission is a secondary vector or as the primary vector of dengue hemorrhagic fever. On viral diseases that attack the nerves like encephalistis Japanese, Western or East­ern encephalistis, and Chikuguya has been demonstrated by laboratories, as well as on ani­mal diseases caused by Dirofilaria immitis agent, Plasmodium lophurae, P. gallinaceum, and P. fallax.

  10. Paradoxical cellular effects and biological role of the multifaceted compound nordihydroguaiaretic acid.

    Science.gov (United States)

    Hernández-Damián, Jacqueline; Andérica-Romero, Ana Cristina; Pedraza-Chaverri, José

    2014-10-01

    Nordihydroguaiaretic acid (NDGA) is a phenolic compound obtained from the leaves of the evergreen desert shrub Larrea tridentata (Creosote bush), which has been used anciently in folk medicine for the treatment of multiple diseases. At the molecular level, NDGA is a potent scavenger of reactive oxygen species. Lipoxygenase inhibition by NDGA has been broadly studied over several cell models; however, NDGA exerts other antioxidant properties and cytoprotective effects in non-tumor cells, which are related with its role as modulator of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) antioxidant pathway. In contrast, in tumor cells NDGA exerts pro-apoptotic activity and anti-tumor effects. Different effects of NDGA have been observed in mitochondria, where NDGA prevents mitochondrial damage in non-tumor cells and induces loss of mitochondrial function in tumor cells. Moreover, NDGA exerts beneficial effects in diverse diseases like cancer, renal damage, Huntington's disease, Alzheimer's disease, and other neurodegenerative pathologies. This work represents a critical review about relevant NDGA mechanisms, cellular effects, and signal pathways involved with possible useful effects.

  11. Overview on the Role of Advance Genomics in Conservation Biology of Endangered Species

    Directory of Open Access Journals (Sweden)

    Suliman Khan

    2016-01-01

    Full Text Available In the recent era, due to tremendous advancement in industrialization, pollution and other anthropogenic activities have created a serious scenario for biota survival. It has been reported that present biota is entering a “sixth” mass extinction, because of chronic exposure to anthropogenic activities. Various ex situ and in situ measures have been adopted for conservation of threatened and endangered plants and animal species; however, these have been limited due to various discrepancies associated with them. Current advancement in molecular technologies, especially, genomics, is playing a very crucial role in biodiversity conservation. Advance genomics helps in identifying the segments of genome responsible for adaptation. It can also improve our understanding about microevolution through a better understanding of selection, mutation, assertive matting, and recombination. Advance genomics helps in identifying genes that are essential for fitness and ultimately for developing modern and fast monitoring tools for endangered biodiversity. This review article focuses on the applications of advanced genomics mainly demographic, adaptive genetic variations, inbreeding, hybridization and introgression, and disease susceptibilities, in the conservation of threatened biota. In short, it provides the fundamentals for novice readers and advancement in genomics for the experts working for the conservation of endangered plant and animal species.

  12. The role of HIV and monocytes/macrophages in adipose tissue biology.

    Science.gov (United States)

    Shikuma, Cecilia M; Gangcuangco, Louie Mar A; Killebrew, Deirdre A; Libutti, Daniel E; Chow, Dominic C; Nakamoto, Beau K; Liang, Chin Yuan; Milne, Cris I P; Ndhlovu, Lishomwa C; Barbour, Jason D; Shiramizu, Bruce T; Gerschenson, Mariana

    2014-02-01

    To assess the role of HIV and monocytes/macrophages in adipose tissue dysregulation. Cross-sectional study in 5 groups: HIV seronegative, HIV+ antiretroviral therapy (ART)-naive, HIV+ nonlipoatrophic on zidovudine- and/or stavudine-containing ART, HIV+ lipoatrophic on similar ART, and HIV+ on abacavir- or tenofovir-containing ART. HIV DNA in circulating monocyte subsets was quantitated by real-time polymerase chain reaction. Biopsied subcutaneous fat was examined for macrophage content by CD68 staining. Isolated adipocytes and macrophages were cultured and the supernatant assayed for secretory products by Luminex multiplex cytokine technology. Sixty-nine subjects were enrolled. Lipoatrophic subjects had higher median HIV DNA levels (270.5 copies/10 cells) in circulating peripheral CD14CD16 co-expressing monocyte subsets compared with subjects who were ART-naive (25.0 copies), nonlipoatrophic (15.0 copies), or on abacavir/tenofovir (57.5 copies), P adipocytes and adipose macrophage content were marginal. Although adipocyte secretory products were similar, HIV-infected subjects had higher adipose macrophage-derived interleukin (IL)-12p40, IL-6, IL-8, and monocyte inflammatory protein 1 alpha and lower eotaxin and interferon gamma levels than HIV seronegative subjects (P adipose macrophage secretory products were comparable between subjects naive with ART versus those on ART. Circulating HIV-infected and proinflammatory CD14CD16 monocyte subsets contribute to the pathogenesis of HIV-associated lipoatrophy. Among HIV-infected individuals, macrophages, rather than adipocytes, are the primary source of low-grade inflammation in subcutaneous adipose tissue. HIV infection modifies these macrophages to a more proinflammatory phenotype, and these changes are not substantially mitigated by the use of ART.

  13. Biological roles and therapeutic potential of hydroxy-carboxylic acid receptors

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    Kashan eAhmed

    2011-10-01

    Full Text Available In the recent past, deorphanization studies have described intermediates of energy metabolism to activate G protein-coupled receptors (GPCRs and to thereby regulate metabolic functions. GPR81, GPR109A and GPR109B, formerly known as the nicotinic acid receptor family, are encoded by clustered genes and share a high degree of sequence homology. Recently, hydroxy-carboxylic acids were identified as endogenous ligands of GPR81, GPR109A and GPR109B, and therefore these receptors have been placed into a novel receptor family of hydroxy-carboxylic acid (HCA receptors. The HCA1 receptor (GPR81 is activated by the glycolytic metabolite 2-hydroxy-propionic acid (lactate, the HCA2 receptor is activated by the ketone body 3-hydroxy-butyric acid and the HCA3 receptor (GPR109B is a receptor for the β-oxidation intermediate 3-hydroxy-octanoic acid. While HCA1 and HCA2 receptors are present in most mammalian species, the HCA3 receptor is exclusively found in humans and higher primates. HCA receptors are expressed in adipose tissue and mediate anti-lipolytic effects in adipocytes through Gi-type G-protein-dependent inhibition of adenylyl cyclase. HCA2 and HCA3 inhibit lipolysis during conditions of increased β-oxidation such as prolonged fasting, whereas HCA1 mediates the anti-lipolytic effects of insulin in the fed state. As HCA2 is a receptor for the established anti-dyslipidemic drug nicotinic acid, HCA1 and HCA3 also represent promising drug targets and several synthetic ligands for HCA receptors have been developed. In this article, we will summarize the deorphanization and pharmacological characterization of HCA receptors. Moreover, we will discuss recent progress in elucidating the physiological and pathophysiological role to further evaluate the therapeutic potential of the HCA receptor family for the treatment of metabolic disease.

  14. The Role of the p53 Protein in Stem-Cell Biology and Epigenetic Regulation.

    Science.gov (United States)

    Levine, Arnold J; Puzio-Kuter, Anna M; Chan, Chang S; Hainaut, Pierre

    2016-09-01

    The p53 protein plays a passive and an active role in stem cells. The transcriptional activities of p53 for cell-cycle arrest and DNA repair are largely turned off in stem cells, but there is some indication that long-term stem-cell viability may require other p53-regulated functions. When p53 is activated in stem cells, it stops cell division and promotes the commitment to a differentiation pathway and the formation of progenitor cells. In the absence of any p53 activity, stem-cell replication continues and mistakes in the normal epigenetic pathway occur at a higher probability. In the presence of a functionally active p53 protein, epigenetic stability is enforced and stem-cell replication is regulated by commitment to differentiation. Over a lifetime of an organism, stem-cell clones compete in a tissue niche for Darwinian replicative advantages and in doing so accumulate mutations that permit stem-cell replication. Mutations in the p53 gene give stem cells this advantage, increase the clonal stem-cell population, and lower the age at which cancers can occur. Li-Fraumeni patients that inherit p53 mutations develop tumors in a tissue-type-specific fashion at younger ages. Throughout the life of a Li-Fraumeni patient, the tumor types that arise occur in tissues where stem cells are active and cell division is most rapid. Thus, p53 mutations that are inherited or occur during developmental life act in stem cells of the mesenchymal and epithelial lineages, whereas p53 mutations that occur in progenitor or differentiated (somatic) cells later in life function in tissues of endodermal origins, indicating that p53 may function differently in different developmental lineages.

  15. Biological roles of cAMP: variations on a theme in the different kingdoms of life.

    Science.gov (United States)

    Gancedo, Juana M

    2013-08-01

    Cyclic AMP (cAMP) plays a key regulatory role in most types of cells; however, the pathways controlled by cAMP may present important differences between organisms and between tissues within a specific organism. Changes in cAMP levels are caused by multiple triggers, most affecting adenylyl cyclases, the enzymes that synthesize cAMP. Adenylyl cyclases form a large and diverse family including soluble forms and others with one or more transmembrane domains. Regulatory mechanisms for the soluble adenylyl cyclases involve either interaction with diverse proteins, as happens in Escherichia coli or yeasts, or with calcium or bicarbonate ions, as occurs in mammalian cells. The transmembrane cyclases can be regulated by a variety of proteins, among which the α subunit and the βγ complex from G proteins coupled to membrane receptors are prominent. cAMP levels also are controlled by the activity of phosphodiesterases, enzymes that hydrolyze cAMP. Phosphodiesterases can be regulated by cAMP, cGMP or calcium-calmodulin or by phosphorylation by different protein kinases. Regulation through cAMP depends on its binding to diverse proteins, its proximal targets, this in turn causing changes in a variety of distal targets. Specifically, binding of cAMP to regulatory subunits of cAMP-dependent protein kinases (PKAs) affects the activity of substrates of PKA, binding to exchange proteins directly activated by cAMP (Epac) regulates small GTPases, binding to transcription factors such as the cAMP receptor protein (CRP) or the virulence factor regulator (Vfr) modifies the rate of transcription of certain genes, while cAMP binding to ion channels modulates their activity directly. Further studies on cAMP signalling will have important implications, not only for advancing fundamental knowledge but also for identifying targets for the development of new therapeutic agents.

  16. Investigation of role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4PTMBC and 1IPMBC.

    Science.gov (United States)

    Raghavendra, U P; Basanagouda, Mahantesha; Thipperudrappa, J

    2015-01-01

    The role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4-p-tolyloxymethyl-benzo[h]coumarin (4PTMBC) and 1-(4-iodophenoxymethyl)-benzo[f]coumarin (1IPMBC) has been investigated using absorption and fluorescence spectroscopy. Silver nanoparticles are synthesized by chemical reduction method and the estimated size by Mie theory is 12 nm. The absorption spectral changes of dyes in the presence of silver nanoparticles suggest their possible interaction with silver nanoparticles. The apparent association constants of the interaction are estimated using Benesi-Hildebrand model. Fluorescence quenching has been observed in both the dyes with the addition of silver nanoparticles. The Stern-Volmer plots of fluorescence quenching are found to be nonlinear showing positive deviation. The magnitudes of quenching rate parameter and fluorescence lifetime measurements indicate the presence of both collisional and static quenching mechanisms. The binding constants and the number of binding sites for the static type of quenching have been estimated from the fluorescence data. The role of diffusion, energy transfer and electron transfer processes in fluorescence quenching mechanism has been discussed.

  17. Biological phosphorus removal in an extended ASM2 model: Roles of extracellular polymeric substances and kinetic modeling.

    Science.gov (United States)

    Yang, Shan-Shan; Pang, Ji-Wei; Guo, Wan-Qian; Yang, Xiao-Yin; Wu, Zhong-Yang; Ren, Nan-Qi; Zhao, Zhi-Qing

    2017-05-01

    This paper presents the results of an extended ASM2 model for the modeling and calibration of the role of extracellular polymeric substances (EPS) in phosphorus (P) removal in an anaerobic-aerobic process. In this extended ASM2 model, two new components, the bound EPS (XEPS) and the soluble EPS (SEPS), are introduced. Compared with the ASM2, 7.71, 8.53, and 9.28% decreases in polyphosphate (polyP) were observed in the extended ASM2 in three sequencing batch reactors feeding with different COD/P ratios, indicating that 7.71-9.28% of P in the liquid was adsorbed by EPS. Sensitive analysis indicated that, five parameters were the significant influential parameters and had been chosen for further model calibration by using the least square method to simulate by MATLAB. This extended ASM2 has been successfully established to simulate the output variables and provides a useful reference for the mathematic simulations of the role of EPS in biological phosphorus removal process. Copyright © 2017. Published by Elsevier Ltd.

  18. TAXONOMIC DIVERSITY AND THE ROLE OF ALGAEFLORA FOR BIOLOGICAL DEPURATION OF WATERS FROM RIVER COGÂLNIC (R. MOLDOVA

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    SALARU VICTOR

    2008-11-01

    Full Text Available During 2004-2005 there were performed studies regarding the taxonomic structure of the algaeflora in river Cogâlnic in order to point out the role of the algae during the process of water quality improvement and the role of the indicator of the most representative species. River Cogâlnic, or Cunduc, starts from nearby village Iurceni, district Nisporeni and flows into lake Sasac, and runs for a distance of 243 km. Decrease of the analyzed water quality from the river is caused by the sewerage waters from different sectors from town Hinceshti and Cimishlia that are directed into the river without any depuration. We've studied about 118 samples in which we've discovered about 382 species and intraspecific taxonomic units of algae of the following types: Cyanophyta -73, Euglenophyta-75, Chlorophyta-111, Xantophyta-3, Bacillariophyta-118 and Chrysophyta-2. Mass development of the euglena within Colgalnic river, among which are the following types of species Euglena-26, Trachelomonas-14 and Phacus-13, demonstrate a high level of trophicity in water. Among the chloride algae predominate the following species Scenedesmus-21, and from cyanophyta species predominates Oscillatoria-23. The high taxonomic level of the bacillariophyta algae is determined by species as Navicula-27, Nitzschia-24 and Surirella-16. Most of species refer to categories β and β-α , demonstrating a high level of water pollution. This fact speaks about the high concentration of nitrogen and phosphor compounds in water. It was demonstrated that as far as we go from the places were the sewerage waters flow into the river, the excessive quantities of biological elements decrease clearly. Also, go down the quantity of bicarbonates and oxidizers. Numeric growth of the algae is nothing else but a positive role for water depuration.

  19. The Role of Chitinase Production by Stenotrophomonas maltophilia Strain C3 in Biological Control of Bipolaris sorokiniana.

    Science.gov (United States)

    Zhang, Z; Yuen, G Y

    2000-04-01

    ABSTRACT The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (>8 kDa) was chitinolytic and more inhibitory than a low-molecular-weight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity chromatography also were chitinolytic and highly antifungal. The chitinolytic fractions caused swelling and vacuolation of conidia and discoloration, malformation, and degradation of germ tubes. When boiled, the chitinolytic fractions lost chitinase activity along with most of the antifungal properties. Two chitinase-deficient and two chitinase-reduced mutants of C3 were compared with the wild-type strain for inhibition of germination of B. sorokiniana conidia on tall fescue leaves and for suppression of leaf spot development in vivo. The mutants exhibited reduced antifungal activity and biocontrol efficacy, but did not lose all biocontrol activity. An aqueous extract of leaves colonized by wild-type C3 had higher chitinase activity than that of noncolonized leaves and was inhibitory to conidial germination. The addition of chitin to leaves along with the wild-type strain increased both chitinase and antifungal activity. The chitinase activity level of extracts from leaves colonized by a chitinase-deficient mutant of C3, with and without added chitin, was no higher than the background, and the extracts lacked antifungal activity. Chitinolysis appears to be one mechanism of biological control by strain C3, and it functions in concert with other mechanisms.

  20. Origin, evolution, and biological role of miRNA cluster in DLK-DIO3 genomic region in placental mammals.

    Science.gov (United States)

    Glazov, Evgeny A; McWilliam, Sean; Barris, Wesley C; Dalrymple, Brian P

    2008-05-01

    MicroRNAs (miRNAs) are a rapidly growing family of small regulatory RNAs modulating gene expression in plants and animals. In animals, most of the miRNAs discovered in early studies were found to be evolutionarily conserved across the whole kingdom. More recent studies, however, have identified many miRNAs that are specific to a particular group of organisms or even a single species. These present a question about evolution of the individual miRNAs and their role in establishing and maintaining lineage-specific functions and characteristics. In this study, we describe a detailed analysis of the miRNA cluster (hereafter mir-379/mir-656 cluster) located within the imprinted DLK-DIO3 region on human chromosome 14. We show that orthologous miRNA clusters are present in all sequenced genomes of the placental (eutherian) mammals but not in the marsupial (metatherian), monotreme (prototherian), or any other vertebrate genomes. We provide evidence that the locus encompassing this cluster emerged in an early eutherian ancestor prior to the radiation of modern placental mammals by tandem duplication of the ancient precursor sequence. The original amplified cluster may have contained in excess of 250 miRNA precursor sequences, most of which now appear to be inactive. Examination of the eutherian genomes showed that the cluster has been maintained in evolution for approximately 100 Myr. Analysis of genes that contain predicted evolutionarily conserved targets for miRNAs from this cluster revealed significant overrepresentation of the Gene Ontology terms associated with biological processes such as neurogenesis, embryonic development, transcriptional regulation, and RNA metabolism. Consistent with these findings, a survey of the miRNA expression data within the cluster demonstrates a strong bias toward brain and placenta samples from adult organisms and some embryonic tissues. Our results suggest that emergence of the mir-379/mir-656 miRNA cluster was one of the factors that

  1. On the role of atmospheric forcing on upper ocean physics in the Southern Ocean and biological impacts

    Science.gov (United States)

    Carranza, Magdalena M.

    The Southern Ocean (SO) plays a key role in regulating climate by absorbing nearly half of anthropogenic carbon dioxide (CO2). Both physical and biogeochemical processes contribute to the net CO2 sink. As a result of global warming and ozone depletion, westerly winds have increased, with consequences for upper ocean physics but little is known on how primary producers are expected to respond to changes in atmospheric forcing. This thesis addresses the impact of atmospheric forcing on upper ocean dynamics and phytoplankton bloom development in the SO on synoptic storm scales, combining a broad range of observations derived from satellites, reanalysis, profiling floats and Southern elephant seals. On atmospheric synoptic timescales (2-10 days), relevant for phytoplankton growth and accumulation, wind speed has a larger impact on satellite Chl-a variability than surface heat fluxes or wind stress curl. In summer, strong winds are linked to deep mixed layers, cold sea surface temperatures and enhanced satellite chlorophyll-a (Chl-a), which suggest wind-driven entrainment plays a role in sustaining phytoplankton blooms at the surface. Subsurface bio-optical data from floats and seals reveal deep Chl-a fluorescence maxima (DFM) are ubiquitous in summer and tend to sit at the base of the mixed layer, but can occur in all seasons. The fact that wind speed and Chl-a correlations are maximal at zero lag time (from daily data) and incubation experiments indicate phytoplankton growth occurs 3-4 days after iron addition, suggests high winds in summer entrain Chl-a from a subsurface maximum. Vertical profiles also reveal Chl-a fluorescence unevenness within hydrographically defined mixed layers, suggesting the biological timescales of adaptation through the light gradient (i.e. growth and/or photoacclimation) are often faster than mixing timescales, and periods of quiescence between storms are long enough for biological gradients to form within the homogeneous layer in density

  2. The Examination of the Effects of Biological Gender and Gender Identity Roles on Attitude of the Consumers to Advertisements Applied by Accomodation Operations

    Directory of Open Access Journals (Sweden)

    Evren Güçer

    2013-12-01

    Full Text Available In this study, especially focused on the concept of psychological-based gender identity and researched if there is a differentiation characteristic of consumers’ sex and gender identity roles (masculinity, femininity, androgynous and neutral on consumers’ attitude toward advertisements of accomodation establishments.According to the results,there is a general accordance between biological sex and gender identity roles of individuals and alsothe results of the previous studies were made in different areas in the same subject was supported with determination ofit is possible to participants have gender identity roles different from their biological sex to some extent.Otherwise; determination of theadvertisements ofaccomodationestablishments, contain feminine messages, are more preferred by people who have feminine and androgynous identity than the others; and advertisements ofaccomodationestablishments, contain masculinemessages, are preferred by all gender identity roles are ones of the results

  3. Corneal Molecular and Cellular Biology for the Refractive Surgeon: The Critical Role of the Epithelial Basement Membrane.

    Science.gov (United States)

    Marino, Gustavo K; Santhiago, Marcony R; Torricelli, Andre A M; Santhanam, Abirami; Wilson, Steven E

    2016-02-01

    To provide an overview of the recent advances concerning the corneal molecular and cellular biology processes involved in the wound healing response after excimer laser surface ablation and LASIK surgery. Literature review. The corneal wound healing response is a complex cascade of events that impacts the predictability and stability of keratorefractive surgical procedures such as photorefractive keratectomy and LASIK. The generation and persistence of corneal myofibroblasts (contractile cells with reduced transparency) arise from the interaction of cytokines and growth factors such as transforming growth factor beta and interleukin 1 produced by epithelial and stromal cells in response to the corneal injury. Myofibroblasts, and the opaque extracellular matrix they secrete into the stroma, disturb the precise distribution and spacing of collagen fibers related to corneal transparency and lead to the development of vision-limiting corneal opacity (haze). The intact epithelial basement membrane has a pivotal role as a structure that regulates corneal epithelial-stromal interactions. Thus, defective regeneration of the epithelial basement membrane after surgery, trauma, or infection leads to the development of stromal haze. The apoptotic process following laser stromal ablation, which is proportional to the level of attempted correction, leads to an early decrease in anterior keratocyte density and the diminished contribution of these non-epithelial cells of components such as perlecan and nidogen-2 required for normal regeneration of the epithelial basement membrane. Haze persists until late repair of the defective epithelial basement membrane. Defective regeneration of the epithelial basement membrane has a critical role in determining whether a cornea heals with late haze after photorefractive keratectomy or with scarring at the flap edge in LASIK. Copyright 2016, SLACK Incorporated.

  4. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae

    Science.gov (United States)

    Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D.

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins’ anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver. PMID:27760211

  5. Antioxidant role of amyloid β protein in cell-free and biological systems: implication for the pathogenesis of Alzheimer disease.

    Science.gov (United States)

    Sinha, Maitrayee; Bhowmick, Pritha; Banerjee, Anindita; Chakrabarti, Sasanka

    2013-03-01

    In contrast to many studies showing the pro-oxidative nature of amyloid peptide, this work shows that aggregated Aβ42 peptide in varying concentrations (2-20 μM) in cell-free systems inhibits the formation of hydroxyl radicals and H(2)O(2) from a mixture of iron (20 μM FeSO(4)) and ascorbate (2mM) as measured by benzoate hydroxylation assay and coumarin carboxylic acid assay. Aggregated Aβ42 in similar concentrations further prevents protein and lipid oxidation in isolated rat brain mitochondria incubated alone or with FeSO(4) and ascorbate. Moreover, mitochondria exposed to FeSO(4) and ascorbate show enhanced formation of reactive oxygen species and this phenomenon is also abolished by aggregated Aβ42. It is suggested that the antioxidant property of Aβ42 in various systems is mediated by metal chelation and it is nearly as potent as a typical metal chelator, such as diethylenetriaminepentaacetic acid, in preventing oxidative damage. However, aggregated Aβ42 causes mitochondrial functional impairment in the form of membrane depolarization and a loss of phosphorylation capacity without involving reactive oxygen species in the process. Thus, the present results suggest that the amyloid peptide exhibits a protective antioxidant role in biological systems, but also has toxic actions independent of oxidative stress.

  6. Particle-Rich Cytoplasmic Structure (PaCS: Identification, Natural History, Role in Cell Biology and Pathology

    Directory of Open Access Journals (Sweden)

    Enrico Solcia

    2014-09-01

    Full Text Available Cytoplasmic structures showing a selective concentration of both polyubiquitinated proteins and proteasome have been described in various epithelial, hematopoietic, mesenchymal and neural cells in vitro or in fetal tissues, as well as in chronically-infected, mutated preneoplastic and neoplastic tissues. These cytoplasmic structures differ from other ubiquitin-reactive cytoplasmic bodies, like sequestosomes, aggresome-like-induced structures in dendritic cells (DALIS/non-dendritic cells (ALIS and aggresomes in showing distinctive ultrastructural organization (particle-rich cytoplasmic structure or PaCS, a cytochemical pattern and a functional profile. Their formation can be induced in vitro in dendritic or natural killer cells by trophic factors and interleukin treatment. They originate in close connection with ribosomes, while, as a result of their growth, the cytoskeleton and other surrounding organelles are usually dislocated outside their core. Interestingly, these particulate cytoplasmic structures are often found to fill cytoplasmic blebs forming proteasome- and polyubiquitinated protein-discharging vesicles, called ectosomes, which are found to detach from the cell and freely float in the extracellular space. To clearly point out the importance of the polyubiquitinated proteins and proteasome containing cytoplasmic structures, their role in cell biology and pathology has been carefully analyzed.

  7. Particle-rich cytoplasmic structure (PaCS): identification, natural history, role in cell biology and pathology.

    Science.gov (United States)

    Solcia, Enrico; Sommi, Patrizia; Necchi, Vittorio; Vitali, Agostina; Manca, Rachele; Ricci, Vittorio

    2014-09-22

    Cytoplasmic structures showing a selective concentration of both polyubiquitinated proteins and proteasome have been described in various epithelial, hematopoietic, mesenchymal and neural cells in vitro or in fetal tissues, as well as in chronically-infected, mutated preneoplastic and neoplastic tissues. These cytoplasmic structures differ from other ubiquitin-reactive cytoplasmic bodies, like sequestosomes, aggresome-like-induced structures in dendritic cells (DALIS)/non-dendritic cells (ALIS) and aggresomes in showing distinctive ultrastructural organization (particle-rich cytoplasmic structure or PaCS), a cytochemical pattern and a functional profile. Their formation can be induced in vitro in dendritic or natural killer cells by trophic factors and interleukin treatment. They originate in close connection with ribosomes, while, as a result of their growth, the cytoskeleton and other surrounding organelles are usually dislocated outside their core. Interestingly, these particulate cytoplasmic structures are often found to fill cytoplasmic blebs forming proteasome- and polyubiquitinated protein-discharging vesicles, called ectosomes, which are found to detach from the cell and freely float in the extracellular space. To clearly point out the importance of the polyubiquitinated proteins and proteasome containing cytoplasmic structures, their role in cell biology and pathology has been carefully analyzed.

  8. Neural sensitivity to statistical regularities as a fundamental biological process that underlies auditory learning: the role of musical practice.

    Science.gov (United States)

    François, Clément; Schön, Daniele

    2014-02-01

    There is increasing evidence that humans and other nonhuman mammals are sensitive to the statistical structure of auditory input. Indeed, neural sensitivity to statistical regularities seems to be a fundamental biological property underlying auditory learning. In the case of speech, statistical regularities play a crucial role in the acquisition of several linguistic features, from phonotactic to more complex rules such as morphosyntactic rules. Interestingly, a similar sensitivity has been shown with non-speech streams: sequences of sounds changing in frequency or timbre can be segmented on the sole basis of conditional probabilities between adjacent sounds. We recently ran a set of cross-sectional and longitudinal experiments showing that merging music and speech information in song facilitates stream segmentation and, further, that musical practice enhances sensitivity to statistical regularities in speech at both neural and behavioral levels. Based on recent findings showing the involvement of a fronto-temporal network in speech segmentation, we defend the idea that enhanced auditory learning observed in musicians originates via at least three distinct pathways: enhanced low-level auditory processing, enhanced phono-articulatory mapping via the left Inferior Frontal Gyrus and Pre-Motor cortex and increased functional connectivity within the audio-motor network. Finally, we discuss how these data predict a beneficial use of music for optimizing speech acquisition in both normal and impaired populations.

  9. Mammalian Exo1 encodes both structural and catalytic functions that play distinct roles in essential biological processes.

    Science.gov (United States)

    Schaetzlein, Sonja; Chahwan, Richard; Avdievich, Elena; Roa, Sergio; Wei, Kaichun; Eoff, Robert L; Sellers, Rani S; Clark, Alan B; Kunkel, Thomas A; Scharff, Matthew D; Edelmann, Winfried

    2013-07-02

    Mammalian Exonuclease 1 (EXO1) is an evolutionarily conserved, multifunctional exonuclease involved in DNA damage repair, replication, immunoglobulin diversity, meiosis, and telomere maintenance. It has been assumed that EXO1 participates in these processes primarily through its exonuclease activity, but recent studies also suggest that EXO1 has a structural function in the assembly of higher-order protein complexes. To dissect the enzymatic and nonenzymatic roles of EXO1 in the different biological processes in vivo, we generated an EXO1-E109K knockin (Exo1(EK)) mouse expressing a stable exonuclease-deficient protein and, for comparison, a fully EXO1-deficient (Exo1(null)) mouse. In contrast to Exo1(null/null) mice, Exo1(EK/EK) mice retained mismatch repair activity and displayed normal class switch recombination and meiosis. However, both Exo1-mutant lines showed defects in DNA damage response including DNA double-strand break repair (DSBR) through DNA end resection, chromosomal stability, and tumor suppression, indicating that the enzymatic function is required for those processes. On a transformation-related protein 53 (Trp53)-null background, the DSBR defect caused by the E109K mutation altered the tumor spectrum but did not affect the overall survival as compared with p53-Exo1(null) mice, whose defects in both DSBR and mismatch repair also compromised survival. The separation of these functions demonstrates the differential requirement for the structural function and nuclease activity of mammalian EXO1 in distinct DNA repair processes and tumorigenesis in vivo.

  10. Role of quantity of additional food to predators as a control in predator-prey systems with relevance to pest management and biological conservation.

    Science.gov (United States)

    Srinivasu, P D N; Prasad, B S R V

    2011-10-01

    Necessity to understand the role of additional food as a tool in biological control programs is being increasingly felt, particularly due to its eco-friendly nature. A thorough mathematical analysis in this direction revealed the vital role of quality and quantity of the additional food in the controllability of the predator-prey systems. In this article controllability of the additional food--provided predator-prey system is studied from perspectives of pest eradication and biological conservation. Time optimal paths have been constructed to drive the state of the system to a desired terminal state by choosing quantity of the additional food as control variable. The theory developed in this article has been illustrated by solving problems related to pest eradication and biological conservation.

  11. Role of the cyclic lipopeptide massetolide A in biological control of Phytophthora infestans and in colonization of tomato plants by Pseudomonas fluorescens

    NARCIS (Netherlands)

    Tran, H.; Ficke, A.; Asiimwe, T.; Höfte, M.; Raaijmakers, J.M.

    2007-01-01

    Pseudomonas strains have shown promising results in biological control of late blight caused by Phytophthora infestans. However, the mechanism(s) and metabolites involved are in many cases poorly understood. Here, the role of the cyclic lipopeptide massetolide A of Pseudomonas fluorescens SS101 in b

  12. Systems biology analysis of hepatitis C virus infection reveals the role of copy number increases in regions of chromosome 1q in hepatocellular carcinoma metabolism

    DEFF Research Database (Denmark)

    Elsemman, Ibrahim; Mardinoglu, Adil; Shoaie, Saeed

    2016-01-01

    Hepatitis C virus (HCV) infection is a worldwide healthcare problem; however, traditional treatment methods have failed to cure all patients, and HCV has developed resistance to new drugs. Systems biology-based analyses could play an important role in the holistic analysis of the impact of HCV...

  13. Defining the role of Porphyromonas gingivalis peptidylarginine deiminase (PPAD) in rheumatoid arthritis through the study of PPAD biology.

    Science.gov (United States)

    Konig, Maximilian F; Paracha, Alizay S; Moni, Malini; Bingham, Clifton O; Andrade, Felipe

    2015-11-01

    Antibodies to citrullinated proteins are a hallmark of rheumatoid arthritis (RA). Porphyromonas gingivalis peptidylarginine deiminase (PPAD) has been implicated in the initiation of RA by generating citrullinated neoantigens and due to its ability to autocitrullinate. To define the citrullination status and biology of PPAD in P gingivalis and to characterise the anti-PPAD antibody response in RA and associated periodontal disease (PD). PPAD in P gingivalis cells and culture supernatant were analysed by immunoblotting and mass spectrometry to detect citrullination. Recombinant PPAD (rPPAD), inactive mutant PPAD (rPPAD(C351S)), and N-terminal truncated PPAD (rPPAD(Ntx)) were cloned and expressed in Escherichia coli. Patients with RA and healthy controls were assayed for IgG antibodies to citrullinated rPPAD and unmodified rPPAD(C351S) by ELISA. Anti-PPAD antibodies were correlated with anti-cyclic citrullinated peptide (third-generation) antibody levels, RA disease activity and PD status. PPAD from P gingivalis is truncated at the N-terminal and C-terminal domains and not citrullinated. Only when artificially expressed in E coli, full-length rPPAD, but not truncated (fully active) rPPAD(Ntx), is autocitrullinated. Anti-PPAD antibodies show no heightened reactivity to citrullinated rPPAD, but are exclusively directed against the unmodified enzyme. Antibodies against PPAD do not correlate with anti-cyclic citrullinated peptide levels and disease activity in RA. By contrast, anti-PPAD antibody levels are significantly decreased in RA patients with PD. PPAD autocitrullination is not the underlying mechanism linking PD and RA. N-terminal processing protects PPAD from autocitrullination and enhances enzyme activity. Anti-PPAD antibodies may have a protective role for the development of PD in patients with RA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. On the role of mesoscale eddies for the biological productivity and biogeochemistry in the eastern tropical Pacific Ocean off Peru

    Directory of Open Access Journals (Sweden)

    L. Stramma

    2013-06-01

    Full Text Available Mesoscale eddies seem to play an important role for both the hydrography and biogeochemistry of the eastern tropical Pacific Ocean (ETSP off Peru. However, detailed surveys of these eddies are not available, which has so far hampered an in depth understanding of their implications for nutrient distribution and biological productivity. In this study three eddies along a section at 16°45' S have been surveyed intensively during R/V Meteor cruise M90 in November 2012. A coastal mode water eddy, an open ocean mode water eddy and an open ocean cyclonic eddy have been identified and sampled in order to determine both their hydrographic properties and their influence on the biogeochemical setting of the ETSP. In the thermocline the temperature of the coastal anticyclonic eddy was up to 2 °C warmer, 0.2 more saline and the swirl velocity was up to 35 cm s–1. The observed temperature and salinity anomalies, as well as swirl velocities of both types of eddies were about twice as large as had been described for the mean eddies in the ETSP and the observed heat and salt anomalies (AHA, ASA show a much larger variability than the mean AHA and ASA. We found that the eddies contributed significantly to productivity by maintaining pronounced subsurface maxima of chlorophyll. Based on a comparison of the coastal (young mode water eddy and the open ocean (old mode water eddy we conclude that the aging of eddies when they detach from the coast and move westward to the open ocean considerably influences the eddies' properties: chlorophyll maxima are weaker and nutrients are subducted. The coastal mode water eddy was found to be a hotspot of nitrogen loss in the OMZ, whereas, the open ocean cyclonic eddy was of negligible importance for nitrogen loss. Our results show that the important role the eddies play in the ETSP can only be fully deciphered and understood through dedicated high spatial and temporal resolution oceanographic/biogeochemical surveys.

  15. Evolution in the Caribbean Classroom: A critical analysis of the role of biology teachers and science standards in shaping evolution instruction in Belize

    Science.gov (United States)

    Nunez, Elvis Enrique; Pringle, Rose M.; Showalter, Kevin Tyler

    2012-10-01

    A survey of the literature on evolution instruction provides evidence that teachers' personal views and understandings can shape instructional approaches and content delivered in science classrooms regardless of established science standards. This study is the first to quantify evolutionary worldviews of in-service teachers in the Caribbean, specifically in Belize, an English-speaking nation with a high school system guided by a regional biology syllabus and strict standardized tests. Using the Measure of Acceptance of the Theory of Evolution (MATE) instrument and knowledge test, we investigated (1) the current level of acceptance and understanding of evolution as given by 97% of high school biology teachers in Belize; (2) the factors associated with acceptance and understanding of evolutionary theory. With an average MATE score of 64.4 and a mean knowledge score of 47.9%, Belizean teachers were classified as having both 'Low Acceptance' and 'Low Understanding' of evolutionary theory. A positive correlation was found between teacher acceptance and understanding of evolution. A review of the Caribbean Secondary Examination Certificate biology syllabus suggests that evolution plays a minimal role in the high school biology classroom. We believe that Belize presents a unique opening for future training on evolution instruction since 57% of the biology teachers self-proclaim to be unprepared to teach evolution. The results of this study have implications for policy, practice and research with teachers' acceptance, understanding and confidence in teaching evolution serving as important predictors for instructional approaches used in the biology classroom.

  16. The role of biological sciences in understanding the genesis and a new therapeutic approach to Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Eugenia Tęgowska

    2011-01-01

    Full Text Available The paper contrasts the historical view on causal factors in Alzheimer’s disease (AD with the modern concept of the symptoms’ origin. Biological sciences dealing with cell structure and physiology enabled comprehension of the role of mitochondrial defects in the processes of formation of neurofibrillary tangles and β-amyloid, which in turn gives hope for developing a new, more effective therapeutic strategy for AD. It has been established that although mitochondria constantly generate free radicals, from which they are protected by their own defensive systems, in some situations these systems become deregulated, which leads to free radical-based mitochondrial defects. This causes an energetic deficit in neurons and a further increase in the free radical pool. As a result, due to compensation processes, formation of tangles and/or acceleration of β-amyloid production takes place. The nature of these processes is initially a protective one, due to their anti-oxidative action, but as the amount of the formations increases, their beneficial effect wanes. They become a storage place for substances enhancing free radical processes, which makes them toxic themselves. It is such an approach to the primary causal factor for AD which lies at the roots of the new view on AD therapy, suggesting the use of methylene blue-based drugs, laser or intranasally applied insulin. A necessary condition, however, for these methods’ effectiveness is definitely an earlier diagnosis of the disease. Although there are numerous diagnostic methods for AD, their low specificity and high price, often accompanied by a considerable level of patient discomfort, make them unsuitable for early, prodromal screening. In this matter a promising method may be provided using an olfactory test, which is an inexpensive and non-invasive method and thus suitable for screening, although as a test of low specificity, it should be combined with other methods. Introducing new methods

  17. 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

    OpenAIRE

    Chohan, Zahid 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 screene...

  18. Role of biology in the air–sea carbon flux in the Bay of Bengal and Arabian Sea

    Indian Academy of Sciences (India)

    M K Sharada; P S Swathi; K S Yajnik; C Kalyani Devasena

    2008-08-01

    A physical-biological-chemical model (PBCM)is used for investigating the seasonal cycle of air –sea carbon flux and for assessing the effect of the biological processes on seasonal time scale in the Arabian Sea (AS)and Bay of Bengal (BoB),where the surface waters are subjected to contrasting physical conditions.The formulation of PBCM is given in Swathi et al (2000),and evaluation of several ammonium-inhibited nitrate uptake models is given in Sharada et al (2005). The PBCM is here first evaluated against JGOFS data on surface pCO2 in AS, Bay of Bengal Process Studies (BoBPS)data on column integrated primary productivity in BoB,and WOCE I1 data on dissolved inorganic carbon (DIC)and alkalinity (ALK)in the upper 500 meters at 9°N in AS and at 10°N in BoB in September –October.There is good qualitative agreement with local quantitative discrepancies. The net effect of biological processes on air –sea carbon flux on seasonal time scale is determined with an auxiliary computational experiment,called the abiotic run,in which the biological processes are turned off.The difference between the biotic run and abiotic run is interpreted as the net effect of biological processes on the seasonal variability of chemical variables.The net biological effect on air –sea carbon flux is found to be highest in southwest monsoon season in the northwest AS, where strong upwelling drives intense new production.The biological effect is larger in AS than in BoB,as seasonal upwelling and mixing are strong in AS,especially in the northeast,while coastal upwelling and mixing are weak in BoB.

  19. Crucial role of the biological barrier at the primary targeted organs in controlling the translocation and toxicity of multi-walled carbon nanotubes in the nematode Caenorhabditis elegans

    Science.gov (United States)

    Wu, Qiuli; Li, Yinxia; Li, Yiping; Zhao, Yunli; Ge, Ling; Wang, Haifang; Wang, Dayong

    2013-10-01

    Multi-walled carbon nanotubes (MWCNTs) can be translocated into the targeted organs of organisms. We employed a model organism of the nematode Caenorhabditis elegans to investigate the role of a biological barrier at the primary targeted organs in regulating the translocation and toxicity formation of MWCNTs. A prolonged exposure to MWCNTs at predicted environmental relevant concentrations caused adverse effects associated with both the primary and secondary targeted organs on nematodes. The function of PEGylated modification in reducing MWCNTs toxicity might be mainly due to the suppression of their translocation into secondary targeted organs through the primary targeted organs. A biological barrier at the primary targeted organs contributed greatly to the control of MWCNTs translocation into secondary targeted organs, as indicated by functions of Mn-SODs required for prevention of oxidative stress in the primary targeted organs. Over-expression of Mn-SODs in primary targeted organs effectively suppressed the translocation and toxicity of MWCNTs. Our work highlights the crucial role of the biological barrier at the primary targeted organs in regulating the translocation and toxicity formation of MWCNTs. Our data also shed light on the future development of engineered nanomaterials (ENMs) with improved biocompatibility and design of prevention strategies against ENMs toxicity.Multi-walled carbon nanotubes (MWCNTs) can be translocated into the targeted organs of organisms. We employed a model organism of the nematode Caenorhabditis elegans to investigate the role of a biological barrier at the primary targeted organs in regulating the translocation and toxicity formation of MWCNTs. A prolonged exposure to MWCNTs at predicted environmental relevant concentrations caused adverse effects associated with both the primary and secondary targeted organs on nematodes. The function of PEGylated modification in reducing MWCNTs toxicity might be mainly due to the suppression

  20. Global metabolic profiling and its role in systems biology to advance personalized medicine in the 21st century.

    Science.gov (United States)

    Schnackenberg, Laura K

    2007-05-01

    Systems biology attempts to elucidate the complex interaction between genes, proteins and metabolites to provide a mechanistic understanding of cellular function and how this function is affected by disease processes, drug toxicity or drug efficacy effects. Global metabolic profiling is an important component of systems biology that can be applied in both preclinical and clinical settings for drug discovery and development, and to study disease mechanisms. The metabolic profile encodes the phenotype, which is composed of the genotype and environmental factors. The phenotypic profile can be used to make decisions about the best course of treatment for an individual patient. Understanding the combined effects of genetics and environment through a systems biology framework will enable the advancement of personalized medicine.

  1. The role of low-grade inflammation and metabolic flexibility in aging and nutritional modulation thereof: a systems biology approach.

    Science.gov (United States)

    Calçada, Dulce; Vianello, Dario; Giampieri, Enrico; Sala, Claudia; Castellani, Gastone; de Graaf, Albert; Kremer, Bas; van Ommen, Ben; Feskens, Edith; Santoro, Aurelia; Franceschi, Claudio; Bouwman, Jildau

    2014-01-01

    Aging is a biological process characterized by the progressive functional decline of many interrelated physiological systems. In particular, aging is associated with the development of a systemic state of low-grade chronic inflammation (inflammaging), and with progressive deterioration of metabolic function. Systems biology has helped in identifying the mediators and pathways involved in these phenomena, mainly through the application of high-throughput screening methods, valued for their molecular comprehensiveness. Nevertheless, inflammation and metabolic regulation are dynamical processes whose behavior must be understood at multiple levels of biological organization (molecular, cellular, organ, and system levels) and on multiple time scales. Mathematical modeling of such behavior, with incorporation of mechanistic knowledge on interactions between inflammatory and metabolic mediators, may help in devising nutritional interventions capable of preventing, or ameliorating, the age-associated functional decline of the corresponding systems.

  2. The role of low-grade inflammation and metabolic flexibility in aging and nutritional modulation thereof: A systems biology approach

    NARCIS (Netherlands)

    Calçada, D.; Vianello, D.; Giampieri, E.; Sala, C.; Castellani, G.; Graaf, A.A. de; Kremer, S.H.A.; Ommen, B. van; Feskens, E.; Santoro, A.; Franceschi, C.; Bouwman, J.

    2014-01-01

    Aging is a biological process characterized by the progressive functional decline of many interrelated physiological systems. In particular, aging is associated with the development of a systemic state of low-grade chronic inflammation (inflammaging), and with progressive deterioration of metabolic

  3. The role of low-grade inflammation and metabolic flexibility in aging and nutritional modulation thereof: a systems biology approach

    NARCIS (Netherlands)

    Viegas Calcada, D.I.; Vianello, D.; Giampieri, E.; Sala, C.; Castellani, G.; Graaf, de A.; Kremer, B.; Ommen, van B.; Feskens, E.J.M.; Santoro, A.; Franceschi, C.; Bouwman, J.

    2014-01-01

    Aging is a biological process characterized by the progressive functional decline of many interrelated physiological systems. In particular, aging is associated with the development of a systemic state of low-grade chronic inflammation (inflammaging), and with progressive deterioration of metabolic

  4. Mannose-Binding Lectin: Biologic Characteristics and Role in the Susceptibility to Infections and Ischemia-Reperfusion Related Injury in Critically Ill Neonates

    Directory of Open Access Journals (Sweden)

    Cinzia Auriti

    2017-01-01

    Full Text Available The mannose-binding lectin (MBL is a member of the collectin family, belonging to the innate immunity system. Genetic, biologic, and clinical properties of MBL have been widely investigated throughout the last decades, although some interesting aspects of its potential clinical relevance are still poorly understood. Low circulating concentrations of MBL have been associated with increased risk of infection and poor neurologic outcome in neonates. On the other hand, an excessive and uncontrolled inflammatory response by the neonatal intestine after the exposure to luminal bacteria, leading to an increased production of MBL, may be involved in the onset of necrotizing enterocolitis. The purpose of the present review is to summarize the current knowledge about genetic and biologic characteristics of MBL and its role in the susceptibility to infections and to ischemia-reperfusion related tissue injuries to better explore its clinical relevance during the perinatal period and the possible future therapeutic applications.

  5. The role of biological agents in the management of large vessel vasculitis (LVV: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Mohammed Osman

    Full Text Available BACKGROUND: Giant cell arteritis (GCA and Takayasu's arteritis (TAA are large vessel vasculitides (LVV for which corticosteroids (CS are the mainstay for treatment. In patients with LVV unable to tolerate CS, biological agents have been used with variable effectiveness. OBJECTIVE: To systematically review the effectiveness and safety of biological agents in patients with LVV. METHODS: We searched 5 electronic databases (inception to October 2012 and conference abstracts with no language restrictions. Two reviewers independently selected studies, extracted data and assessed methodological quality. Our protocol was registered in PROSPERO. RESULTS: We included 25 studies (3 RCTs and 22 case series with ≥2 cases. 95 GCA and 98 TAA patients received biological agents. The RCTs using anti-TNF agents (infliximab, etanercept and adalimumab did not suggest a benefit in GCA. GCA patients receiving tocilizumab, in case series, achieved remission (19 patients and reduction of corticosteroid dose (mean difference, -16.55 mg/day (95% CI: -26.24, -6.86. In case series, 75 patients with refractory TAA treated with infliximab discontinued CS 32% of the time. Remission was variably defined and the studies were clinically heterogeneous which precluded further analysis. CONCLUSION: This systematic review demonstrated a weak evidence base on which to assess the effectiveness of biological treatment in LVV. Evidence from RCTs suggests that anti-TNF agents are not effective for remission or reduction of CS use. Tocilizumab and infliximab may be effective in the management of LVV and refractory TAA, respectively, although the evidence comes from case series. Future analytical studies are needed to confirm these findings.

  6. Neonatal morbidity associated with late preterm and early term birth: the roles of gestational age and biological determinants of preterm birth

    Science.gov (United States)

    Brown, Hilary K; Speechley, Kathy Nixon; Macnab, Jennifer; Natale, Renato; Campbell, M Karen

    2014-01-01

    Background The aim of this study was to elucidate the role of gestational age in determining the risk of neonatal morbidity among infants born late preterm (34–36 weeks) and early term (37–38 weeks) compared with those born full term (39–41 weeks) by examining the contribution of gestational age within the context of biological determinants of preterm birth. Methods This was a retrospective cohort study. The sample included singleton live births with no major congenital anomalies, delivered at 34–41 weeks of gestation to London-Middlesex (Canada) mothers in 2002–11. Data from a city-wide perinatal database were linked with discharge abstract data. Multivariable models used modified Poisson regression to directly estimate adjusted relative risks (aRRs). The roles of gestational age and biological determinants of preterm birth were further examined using mediation and moderation analyses. Results Compared with infants born full term, infants born late preterm and early term were at increased risk for neonatal intensive care unit triage/admission [late preterm aRR = 6.14, 95% confidence interval (CI) 5.63, 6.71; early term aRR = 1.54, 95% CI 1.41, 1.68] and neonatal respiratory morbidity (late preterm aRR = 6.16, 95% CI 5.39, 7.03; early term aRR = 1.46, 95% CI 1.29, 1.65). The effect of gestational age was partially explained by biological determinants of preterm birth acting through gestational age. Moreover, placental ischaemia and other hypoxia exacerbated the effect of gestational age on poor outcomes. Conclusions Poor outcomes among infants born late preterm and early term are not only due to physiological immaturity but also to biological determinants of preterm birth acting through and with gestational age to produce poor outcomes. PMID:24374829

  7. Quantitative redox biology: an approach to understand the role of reactive species in defining the cellular redox environment.

    Science.gov (United States)

    Buettner, Garry R; Wagner, Brett A; Rodgers, Victor G J

    2013-11-01

    Systems biology is now recognized as a needed approach to understand the dynamics of inter- and intra-cellular processes. Redox processes are at the foundation of nearly all aspects of biology. Free radicals, related oxidants, and antioxidants are central to the basic functioning of cells and tissues. They set the cellular redox environment and, therefore, are the key to regulation of biochemical pathways and networks, thereby influencing organism health. To understand how short-lived, quasi-stable species, such as superoxide, hydrogen peroxide, and nitric oxide, connect to the metabolome, proteome, lipidome, and genome we need absolute quantitative information on all redox active compounds as well as thermodynamic and kinetic information on their reactions, i.e., knowledge of the complete redoxome. Central to the state of the redoxome are the interactive details of the superoxide/peroxide formation and removal systems. Quantitative information is essential to establish the dynamic mathematical models needed to reveal the temporal evolution of biochemical pathways and networks. This new field of Quantitative Redox Biology will allow researchers to identify new targets for intervention to advance our efforts to achieve optimal human health.

  8. Churg-Strauss vasculitis and idiopathic hypereosinophyl syndrome: role of molecular biology in the differential diagnosis of hypereosinophyl syndrome

    Directory of Open Access Journals (Sweden)

    A. d'Ascanio

    2011-09-01

    Full Text Available Objective: Hypereosinophilic syndromes are a heterogeneous group of uncommon disorders characterized by the presence of marked peripheral blood eosinophilia, tissue eosinophilia, or both, resulting in a wide variety of clinical manifestations, often without an identifiable cause. Churg-Strauss syndrome is a systemic vasculitis characterized by prominent peripheral eosinophilia, asthma and systemic involvement. The presence of mild to severe eosinophilia and systemic involvement raise the search of many trigger factor that need to be ruled out. Distinguishing CSS from idiopathic hypereosinophilic syndrome may be particularly challenging, especially in ANCA negative patients. Methods: The aim of the present study was to present a small case series of patients referred to a Rheumatology Unit for mild to severe eosinophilia and signs and symptoms of systemic involvement and to outline the clinical significance of molecular biology in the work-up of hypereosinophilia. Results: Eleven patients with moderate to severe peripheral eosinophylia, were referred to our Unit from 1996 to 2007. Female to male ratio was 7/4, mean age 40.54 (range 22-75. Three out of eleven patients resulted positive for molecular biology. The diagnosis of idiopathic hypereosinophylia was confirmed in one out of three on the basis of the clinical picture and bone marrow biopsy. Conclusions: Molecular biology may be useful in the screening and in the follow-up of a new hypereosinophylic patient.

  9. [The inversion of concepts about biological role of system rennin-angiotensin II- aldosterone and functions of arterial tension as a metabolism regulator].

    Science.gov (United States)

    Titov, V N

    2015-02-01

    The phylogenetic theory of general pathology postulates that in physiology and pathology the concepts of biological role of arterial tension had been subjected to inversion. The activation by nephron of synthesis of components rennin-angiotensin II and increasing of aldosterone secretion are directed not to increase arterial tension but to preserve volume of piece of third world ocean privatized by each entity as pool of intercellular medium where all cells continue to live as billions years before. In phylogenetic sense, early organs can't regulate effect of physical factor of regulation of metabolism the late one in phylogenesis of arterial tension. The cause of increasing of arterial tension is the vasomotor center but not the kidneys. The vasomotor center increases arterial tension in the proximal section and further hydrodynamic tension in the distal section of arterial stream and tends to resuscitate function of nephrons, biological function of endoecology and biological reaction of excretion. The arterial tension, besides the main role in biological function of locomotion, is a physical factor of compensation of disorders of biological functions of homeostasis, trophology, endoecology and adaptation. In phylogenesis, three levels of metabolism regulation has been developed The specific regulation of biochemical reactions occurs on autocrine level. In paracrin regulated cell cenosises, at distal section of arterial stream, metabolism is regulated by billions of local peristaltic pumps through compensation of biological reaction of endothelium-depended vasodilatation, micro-circulation, effect of humoral mediators and hormonal principles. In vivo, from the level of vasomotor center, metabolism non-specifically and systemic regulates physical factor-arterial tension through sympathetic activation of heart. The arterial tension in proximal section of arterial stream overcomes resistance and physically "forces through" arterioles with disordered micro

  10. A computational functional genomics based self-limiting self-concentration mechanism of cell specialization as a biological role of jumping genes.

    Science.gov (United States)

    Lötsch, Jörn; Ultsch, Alfred

    2016-01-01

    Specialization is ubiquitous in biological systems and its manifold mechanisms are active research topics. Although clearly adaptive, the way in which specialization of cells is realized remains incompletely understood as it requires the reshaping of a cell's genome to favor particular biological processes in the competition on a cell's functional capacity. Here, a self-specialization mechanism is identified as a possible biological role of jumping genes, in particular LINE-1 retrotransposition. The mechanism is self-limiting and consistent with its evolutionary preservation despite its likely gene-breaking effects. The scenario we studied was the need for a cell to process a longer exposition to an extraordinary situation, for example continuous exposure to the nociceptive input or the intake of addictive drugs. Both situations may evolve toward chronification. The mechanism involves competition within a gene set in which a subset of genes cooperating in particular biological processes. The subset carries a piece of information, consisting of the LINE-1 sequence, about the destruction of their functional competitor genes which are not involved in that process. During gene transcription, an active copy of LINE-1 is co-transcribed. At a certain low probability, a subsequently transcribed and thus actually exposed gene can be rendered nonfunctional by LINE-1 retrotransposition in a relevant gene part. As retrotransposition needs time it is unlikely that LINE-1 retrotranspose into its own carrier gene. This reshapes the cell genome toward self-specializing of those biological processes that are carried out with a high number of LINE-1 containing genes. Self-termination of the mechanism is achieved by allowing LINE-1 to also occasionally jump into the coding region of itself, thus destroying the information about competitor destruction by successively decreasing the number of LINE-1 until the mechanism ceases. Employing a computational functional genomics approach, we

  11. Serine Protease Inhibitors in Ticks: An Overview of Their Role in Tick Biology and Tick-Borne Pathogen Transmission

    Directory of Open Access Journals (Sweden)

    Adrien A. Blisnick

    2017-05-01

    Full Text Available New tick and tick-borne pathogen control approaches that are both environmentally sustainable and which provide broad protection are urgently needed. Their development, however, will rely on a greater understanding of tick biology, tick-pathogen, and tick-host interactions. The recent advances in new generation technologies to study genomes, transcriptomes, and proteomes has resulted in a plethora of tick biomacromolecular studies. Among these, many enzyme inhibitors have been described, notably serine protease inhibitors (SPIs, whose importance in various tick biological processes is only just beginning to be fully appreciated. Among the multiple active substances secreted during tick feeding, SPIs have been shown to be directly involved in regulation of inflammation, blood clotting, wound healing, vasoconstriction and the modulation of host defense mechanisms. In light of these activities, several SPIs were examined and were experimentally confirmed to facilitate tick pathogen transmission. In addition, to prevent coagulation of the ingested blood meal within the tick alimentary canal, SPIs are also involved in blood digestion and nutrient extraction from the meal. The presence of SPIs in tick hemocytes and their involvement in tick innate immune defenses have also been demonstrated, as well as their implication in hemolymph coagulation and egg development. Considering the involvement of SPIs in multiple crucial aspects of tick-host-pathogen interactions, as well as in various aspects of the tick parasitic lifestyle, these molecules represent highly suitable and attractive targets for the development of effective tick control strategies. Here we review the current knowledge regarding this class of inhibitors in tick biology and tick-borne pathogen transmission, and their potential as targets for future tick control trials.

  12. The role of nuclear reactions in Monte Carlo calculations of absorbed and biological effective dose distributions in hadron therapy

    CERN Document Server

    Brons, S; Elsässer, T; Ferrari, A; Gadioli, E; Mairani, A; Parodi, K; Sala, P; Scholz, M; Sommerer, F

    2010-01-01

    Monte Carlo codes are rapidly spreading among hadron therapy community due to their sophisticated nuclear/electromagnetic models which allow an improved description of the complex mixed radiation field produced by nuclear reactions in therapeutic irradiation. In this contribution results obtained with the Monte Carlo code FLUKA are presented focusing on the production of secondary fragments in carbon ion interaction with water and on CT-based calculations of absorbed and biological effective dose for typical clinical situations. The results of the simulations are compared with the available experimental data and with the predictions of the GSI analytical treatment planning code TRiP.

  13. Insights from the metagenome of an acid salt lake: the role of biology in an extreme depositional environment.

    Science.gov (United States)

    Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L; Benison, Kathleen Counter

    2015-01-01

    The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars.

  14. Investigating the Role of an Inquiry-Based Biology Lab Course on Student Attitudes and Views toward Science.

    Science.gov (United States)

    Jeffery, Erica; Nomme, Kathy; Deane, Thomas; Pollock, Carol; Birol, Gülnur

    2016-01-01

    Students' academic experiences can influence their conceptualization of science. In contrast experts hold particular beliefs, perceptions, opinions, and attitudes about science that are often absent in first-year undergraduate students. Shifts toward more expert-like attitudes and views have been linked to improved student engagement, critical-thinking ability, conceptual understanding, and academic performance. In this study, we investigate shifts in attitudes and views toward science by students in four biology classes with differences in student enrollment, academic support, and instruction. We observe significant, positive effects of enrollment in a guided-inquiry lab course and academic performance on the percentage of expert-like student attitudes and views at the end of term. We also identify variation in two aspects of student attitudes and views: 1) confidence and interest and 2) understanding and acceptance. In particular, enrollment in the lab course boosts student confidence and interest in scientific inquiry in the short term, even for students with low academic performance or little English-language experience. Our results suggest that low-performing students in particular may require additional opportunities for experiential learning or greater academic support to develop expert-like perceptions of biology as a science.

  15. Comparative pollination biology of Venezuelan columnar cacti and the role of nectar-feeding bats in their sexual reproduction.

    Science.gov (United States)

    Nassar, J; Ramirez, N; Linares, O

    1997-07-01

    The floral biology, reproductive system, and visitation behavior of pollinators of four species of columnar cacti, Stenocereus griseus, Pilosocereus moritzianus, Subpilocereus repandus, and Subpilocereus horrispinus, were studied in two arid zones in the north of Venezuela. Our results support the hypothesis that Venezuelan species of columnar cacti have evolved toward specialization on bat pollination. Additional information on the floral biology of a fifth species, Pilosocereus lanuginosus, was also included. All species showed the typical traits that characterize the pollination syndrome of chiropterophily. All species but Pilosocereus moritzianus were obligate outcrossers. Nectar and pollen were restricted to nocturnal floral visitors. Two species of nectar-feeding bats, Leptonycteris curasoae Miller and Glossophaga longirostris Miller, were responsible for practically all the fruit set in these cacti. Frequency of bat visitation per flower per night was highly variable within and between species of cactus, with average frequencies varying between 27 and 78 visits/flower/night. In general terms, the pattern of floral visitation through the night was significantly correlated with the pattern of nectar production and nectar sugar concentration for all species of cactus. Under natural pollination, fruit:flower ratios varied from 0.46 in Subpilocereus repandus to 0.76 in Stenocereus griseus. The efficiency of bat pollination in terms of seed:ovule ratio was high in all species, varying between 0.70 and 0.94.

  16. The Role of Anthropogenic Influence on Biological Signal Field (BSF Characteristics of the Wolf, Canis lupus lupus (Canidae, Carnivora

    Directory of Open Access Journals (Sweden)

    Shkvyria M. G.

    2016-02-01

    Full Text Available The main goal of the current research includes studying the biological signal field (BSF characteristics of the wolf (Canis lupus lupus Linnaeus, 1758 at different values of anthropogenic load on territories with conservation (Białowieża National park (Poland and hunting status of the species (Chornobyl Exclusion Zone (Ukraine. The research in Białowieża Primeval Forest was conducted in two stages: study of the BSF characteristics of the wolf and finding correlation between data acquired from Ukraine (the first stage, and over-time study of intensity of the biological signal field (the second stage. In result of the first stage, there was no significant dependence on the characteristics of the territory and the differences between the behavior of wolves in the Białowieża Primeval Forest (conservation status of the species and the Exclusion Zone (game status. During the second stage it was determined that provided variance of the intensity between territory groups was insufficient, the degree of significance to animals of area categories varied with the stages of the pack’s life. It was found that the main factors which govern the character of wolf activity are not the level of the anthropic load and hunting pressure, but periods of the life cycle and spatial structure of groups.

  17. A promising future for integrative biodiversity research: an increased role of scale-dependency and functional biology.

    Science.gov (United States)

    Price, S A; Schmitz, L

    2016-04-05

    Studies into the complex interaction between an organism and changes to its biotic and abiotic environment are fundamental to understanding what regulates biodiversity. These investigations occur at many phylogenetic, temporal and spatial scales and within a variety of biological and geological disciplines but often in relative isolation. This issue focuses on what can be achieved when ecological mechanisms are integrated into analyses of deep-time biodiversity patterns through the union of fossil and extant data and methods. We expand upon this perspective to argue that, given its direct relevance to the current biodiversity crisis, greater integration is needed across biodiversity research. We focus on the need to understand scaling effects, how lower-level ecological and evolutionary processes scale up and vice versa, and the importance of incorporating functional biology. Placing function at the core of biodiversity research is fundamental, as it establishes how an organism interacts with its abiotic and biotic environment and it is functional diversity that ultimately determines important ecosystem processes. To achieve full integration, concerted and ongoing efforts are needed to build a united and interactive community of biodiversity researchers, with education and interdisciplinary training at its heart.

  18. Systems biology reveals new strategies for personalizing cancer medicine and confirms the role of PTEN in resistance to trastuzumab.

    Science.gov (United States)

    Faratian, Dana; Goltsov, Alexey; Lebedeva, Galina; Sorokin, Anatoly; Moodie, Stuart; Mullen, Peter; Kay, Charlene; Um, In Hwa; Langdon, Simon; Goryanin, Igor; Harrison, David J

    2009-08-15

    Resistance to targeted cancer therapies such as trastuzumab is a frequent clinical problem not solely because of insufficient expression of HER2 receptor but also because of the overriding activation states of cell signaling pathways. Systems biology approaches lend themselves to rapid in silico testing of factors, which may confer resistance to targeted therapies. Inthis study, we aimed to develop a new kinetic model that could be interrogated to predict resistance to receptor tyrosine kinase (RTK) inhibitor therapies and directly test predictions in vitro and in clinical samples. The new mathematical model included RTK inhibitor antibody binding, HER2/HER3 dimerization and inhibition, AKT/mitogen-activated protein kinase cross-talk, and the regulatory properties of PTEN. The model was parameterized using quantitative phosphoprotein expression data from cancer cell lines using reverse-phase protein microarrays. Quantitative PTEN protein expression was found to be the key determinant of resistance to anti-HER2 therapy in silico, which was predictive of unseen experiments in vitro using the PTEN inhibitor bp(V). When measured in cancer cell lines, PTEN expression predicts sensitivity to anti-HER2 therapy; furthermore, this quantitative measurement is more predictive of response (relative risk, 3.0; 95% confidence interval, 1.6-5.5; P biology approach has successfully been used to stratify patients for personalized therapy in cancer and is further compelling evidence that PTEN, appropriately measured in the clinical setting, refines clinical decision making in patients treated with anti-HER2 therapies.

  19. The M3 phosphorylation site is required for trafficking and biological roles of PIN-FORMED1, 2, and 7 in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Daeeun Ki

    2016-09-01

    Full Text Available Asymmetrically localized PIN-FORMED (PIN auxin efflux carriers play key roles in regulating directional intercellular auxin movement, generating local auxin gradients, and diverse auxin-mediated growth and development. The polar localization of PINs is controlled by phosphorylation in the central hydrophilic loop (HL of PINs. Although the M3 phosphorylation site, including phosphorylatable 5 Ser/Thr residues, is conserved among long HL-PINs, its native role has only been characterized in PIN3. In this study, we examined the role of M3 phosphorylation site of PIN1, PIN2, and PIN7 in intracellular trafficking, phosphorylation, and biological functions of those PINs in their native expressing tissues. Phosphorylation-defective mutations of the phosphorylatable residues in the M3 site of PIN1-HL led to alteration in subcellular polarity of PIN1 and caused defects in PIN1-mediated biological functions such as cotyledon development, phyllotaxy of vegetative leaves, and development of reproductive organs. The M3 mutations of PIN7 interfered with its polar recycling in the root columella cell in response to gravity stimulus and partially disrupted root gravitropism. On the other hand, the M3 site of PIN2 was shown to be necessary for its targeting to the plasma membrane. In vitro phosphorylation assay showed that the M3 phosphorylation residues of PIN1 are the partial targets by PINOID kinase. Our data suggest that the M3 phosphorylation site is functionally conserved among long HL-PINs by playing roles for their subcellular trafficking and auxin-mediated developmental processes.

  20. The M3 Phosphorylation Site Is Required for Trafficking and Biological Roles of PIN-FORMED1, 2, and 7 in Arabidopsis

    Science.gov (United States)

    Ki, Daeeun; Sasayama, Daisuke; Cho, Hyung-Taeg

    2016-01-01

    Asymmetrically localized PIN-FORMED (PIN) auxin efflux carriers play key roles in regulating directional intercellular auxin movement, generating local auxin gradients, and diverse auxin-mediated growth and development. The polar localization of PINs is controlled by phosphorylation in the central hydrophilic loop (HL) of PINs. Although the M3 phosphorylation site, including phosphorylatable 5 Ser/Thr residues, is conserved among long HL-PINs, its native role has only been characterized in PIN3. In this study, we examined the role of M3 phosphorylation site of PIN1, PIN2, and PIN7 in intracellular trafficking, phosphorylation, and biological functions of those PINs in their native expressing tissues. Phosphorylation-defective mutations of the phosphorylatable residues in the M3 site of PIN1-HL led to alteration in subcellular polarity of PIN1 and caused defects in PIN1-mediated biological functions such as cotyledon development, phyllotaxy of vegetative leaves, and development of reproductive organs. The M3 mutations of PIN7 interfered with its polar recycling in the root columella cell in response to gravity stimulus and partially disrupted root gravitropism. On the other hand, the M3 site of PIN2 was shown to be necessary for its targeting to the plasma membrane. In vitro phosphorylation assay showed that the M3 phosphorylation residues of PIN1 are the partial targets by PINOID kinase. Our data suggest that the M3 phosphorylation site is functionally conserved among long HL-PINs by playing roles for their subcellular trafficking and auxin-mediated developmental processes.

  1. Why Dogs Have Puppies and Cats Have Kittens: The Role of Birth in Young Children's Understanding of Biological Origins.

    Science.gov (United States)

    Johnson, Susan C.; Solomon, Gregg E. A.

    1997-01-01

    Three studies used interspecies adoption stories to examine children's understanding of the role of birth in determining animal properties and species identity. Found that most 4- to 7-year olds could reliably judge that babies would be of the same species as birth parents, but were unable to attribute properties of adoptive parents. (Author/KB)

  2. Biological soil crusts: An organizing principle in dryland ecosystems (aka: the role of biocrusts in arid land hydrology)

    Science.gov (United States)

    Chamizo, Sonia; Belnap, Jayne; Elridge, David J; Issa, Oumarou M

    2016-01-01

    Biocrusts exert a strong influence on hydrological processes in drylands by modifying numerous soil properties that affect water retention and movement in soils. Yet, their role in these processes is not clearly understood due to the large number of factors that act simultaneously and can mask the biocrust effect. The influence of biocrusts on soil hydrology depends on biocrust intrinsic characteristics such as cover, composition, and external morphology, which differ greatly among climate regimes, but also on external factors as soil type, topography and vegetation distribution patterns, as well as interactions among these factors. This chapter reviews the most recent literature published on the role of biocrusts in infiltration and runoff, soil moisture, evaporation and non-rainfall water inputs (fog, dew, water absorption), in an attempt to elucidate the key factors that explain how biocrusts affect land hydrology. In addition to the crust type and site characteristics, recent studies point to the crucial importance of the type of rainfall and the spatial scale at which biocrust effects are analyzed to understand their role in hydrological processes. Future studies need to consider the temporal and spatial scale investigated to obtain more accurate generalizations on the role of biocrusts in land hydrology.

  3. Antimicrobial activity of eumelanin-based hybrids: The role of TiO2 in modulating the structure and biological performance.

    Science.gov (United States)

    Vitiello, Giuseppe; Pezzella, Alessandro; Zanfardino, Anna; Silvestri, Brigida; Giudicianni, Paola; Costantini, Aniello; Varcamonti, Mario; Branda, Francesco; Luciani, Giuseppina

    2017-06-01

    Eco-friendly hybrid Eumelanin-TiO2 nanostructures, recently obtained through in situ methodology based on hydrothermal route, have shown a striking antimicrobial activity, after exposure to oxidative environment, even under visible light induction condition. Nevertheless, the role of each component in defining the efficacy of these biological properties is far from being clearly defined. Furthermore, the effect of oxidative step on hybrids structure has not yet addressed. This study aims at elucidating the role of the ratio between eumelanin precursor, 5,6-dihydroxyindole-2-carboxylic acid (DHICA), and TiO2, for its polymerization in defining morphology and structural organization of TiO2-melanin nanostructures. Furthermore, tests on a Gram-negative Escherichia coli DH5α strain under UV irradiation and even visible light allowed to assess the contribution of each component, as well as of the TiO2-DHICA charge transfer complex to overall biological performance. Finally, results of biocide characterization were combined with spectroscopic evidences to prove that oxidative treatment induces a marked structural modification in melanin thus enhancing overall antimicrobial efficacy. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Cellular response to ionizing radiations: a study of the roles of physics and biology. [Neutrons (14 MeV); X radiation

    Energy Technology Data Exchange (ETDEWEB)

    DeWyngaert, J.K.

    1982-01-01

    A study of the complementary roles of physics and biology in determining the response of cellular systems to ionizing radiations has been conducted. Upon exposure to radiation, a cell responds in a binary (yes/no) manner in terms of its proliferative ability (survival). The relationship between the survival probability and absorbed dose may then be examined in terms of relevant physical and biological parameters. The approach to these studies was to vary the physics and biology independently and observe separately their influences upon the measured effect. Unique to these studies was the use of heterogeneous tumor systems. These are solid tumors found to consist of genetically related but identifiably distinct populations of cells. The two heterogeneous systems studied, a murine system consisting of four subpopulations and a human tumor system with two subpopulations, were exposed to graded doses of 14 MeV neutrons or x-rays and their effectiveness in inducing cell lethality compared. A further examination of the radiation effect involved a study at the chemical level, measuring the ability of oxygen to potentiate the damage produced by photon irradiation. To summarize, the physics, biology and the environment have all been varied, and the systematics of the responses studied. The data were analyzed within the formalisms of the dual theory of radiation action, the repair-misrepair model, and the repair saturation model of cell killing. The change in survival curve shape and the increased effectiveness in cell killing for higher Linear Energy Transfer (LET) radiations (neutrons vs. x-rays) are discussed in relation to explanations in terms of either physical or biochemical processes.

  5. King has no clothes: The role of the military in responding to a terrorist chemical/biological attack. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Osterman, J.L.

    1996-06-14

    The United States has begun a program of counterproliferation in order to preempt the use of WMD by such elements, however, the ability to respond to the terrorist employment of biological/chemical weapons is absent. Given the structure, capability and technical expertise in the Federal Emergency Management Agency (FEMA) and the Federal Bureau of Investigation (FBI), the Department of Defense (DoD) will be tasked to conduct the response to such an incident. The geographical Commander in Chief (CINC) and the appointed Joint Task Force (JTF) commander will ultimately be assigned the response mission. Planning, training and coordination is required to develop a force capable of responding in a timely and coordinated manner.

  6. Fluctuation relations between hierarchical kinetically equivalent networks with Arrhenius-type transitions and their roles in systems and structural biology

    Science.gov (United States)

    Deng, De-Ming; Lu, Yi-Ta; Chang, Cheng-Hung

    2017-06-01

    The legality of using simple kinetic schemes to determine the stochastic properties of a complex system depends on whether the fluctuations generated from hierarchical equivalent schemes are consistent with one another. To analyze this consistency, we perform lumping processes on the stochastic differential equations and the generalized fluctuation-dissipation theorem and apply them to networks with the frequently encountered Arrhenius-type transition rates. The explicit Langevin force derived from those networks enables us to calculate the state fluctuations caused by the intrinsic and extrinsic noises on the free energy surface and deduce their relations between kinetically equivalent networks. In addition to its applicability to wide classes of network related systems, such as those in structural and systems biology, the result sheds light on the fluctuation relations for general physical variables in Keizer's canonical theory.

  7. The Role of Soil Biological Function in Regulating Agroecosystem Services and Sustainability in the Quesungual Agroforestry System

    Science.gov (United States)

    Fonte, S.; Pauli, N.; Rousseau, L.; SIX, J. W. U. A.; Barrios, E.

    2014-12-01

    The Quesungual agroforestry system from western Honduras has been increasingly promoted as a promising alternative to traditional slash-and-burn agriculture in tropical dry forest regions of the Americas. Improved residue management and the lack of burning in this system can greatly impact soil biological functioning and a number of key soil-based ecosystem services, yet our understanding of these processes has not been thoroughly integrated to understand system functionality as a whole that can guide improved management. To address this gap, we present a synthesis of various field studies conducted in Central America aimed at: 1) quantifying the influence of the Quesungual agroforestry practices on soil macrofauna abundance and diversity, and 2) understanding how these organisms influence key soil-based ecosystem services that ultimately drive the success of this system. A first set of studies examined the impact of agroecosystem management on soil macrofauna populations, soil fertility and key soil processes. Results suggest that residue inputs (derived from tree biomass pruning), a lack of burning, and high tree densities, lead to conditions that support abundant, diverse soil macrofauna communities under agroforestry, with soil organic carbon content comparable to adjacent forest. Additionally, there is great potential in working with farmers to develop refined soil quality indicators for improved land management. A second line of research explored interactions between residue management and earthworms in the regulation of soil-based ecosystem services. Earthworms are the most prominent ecosystem engineers in these soils. We found that earthworms are key drivers of soil structure maintenance and the stabilization of soil organic matter within soil aggregates, and also had notable impacts on soil nutrient dynamics. However, the impact of earthworms appears to depend on residue management practices, thus indicating the need for an integrated approach for

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

    Science.gov (United States)

    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

  9. The biological effect of large single doses: a possible role for non-targeted effects in cell inactivation.

    Directory of Open Access Journals (Sweden)

    Marlon R Veldwijk

    Full Text Available BACKGROUND AND PURPOSE: Novel radiotherapy techniques increasingly use very large dose fractions. It has been argued that the biological effect of large dose fractions may differ from that of conventional fraction sizes. The purpose was to study the biological effect of large single doses. MATERIAL AND METHODS: Clonogenic cell survival of MCF7 and MDA-MB-231 cells was determined after direct X-ray irradiation, irradiation of feeder cells, or transfer of conditioned medium (CM. Cell-cycle distributions and the apoptotic sub-G1 fraction were measured by flow cytometry. Cytokines in CM were quantified by a cytokine antibody array. γH2AX foci were detected by immunofluorescence microscopy. RESULTS: The surviving fraction of MCF7 cells irradiated in vitro with 12 Gy showed an 8.5-fold decrease (95% c.i.: 4.4-16.3; P<0.0001 when the density of irradiated cells was increased from 10 to 50×10(3 cells per flask. Part of this effect was due to a dose-dependent transferrable factor as shown in CM experiments in the dose range 5-15 Gy. While no effect on apoptosis and cell cycle distribution was observed, and no differentially expressed cytokine could be identified, the transferable factor induced prolonged expression of γH2AX DNA repair foci at 1-12 h. CONCLUSIONS: A dose-dependent non-targeted effect on clonogenic cell survival was found in the dose range 5-15 Gy. The dependence of SF on cell numbers at high doses would represent a "cohort effect" in vivo. These results support the hypothesis that non-targeted effects may contribute to the efficacy of very large dose fractions in radiotherapy.

  10. Animal lectins as self/non-self recognition molecules. Biochemical and genetic approaches to understanding their biological roles and evolution.

    Science.gov (United States)

    Vasta, G R; Ahmed, H; Fink, N E; Elola, M T; Marsh, A G; Snowden, A; Odom, E W

    1994-04-15

    In recent years, the significant contributions from molecular research studies on animal lectins have elucidated structural aspects and provided clues not only to their evolution but also to their multiple biological functions. The experimental evidence has suggested that distinct, and probably unrelated, groups of molecules are included under the term "lectin." Within the invertebrate taxa, major groups of lectins can be identified: One group would include lectins that show significant homology to membrane-integrated or soluble vertebrate C-type lectins. The second would include those beta-galactosyl-specific lectins homologous to the S-type vertebrate lectins. The third group would be constituted by lectins that show homology to vertebrate pentraxins that exhibit lectin-like properties, such as C-reactive protein and serum amyloid P. Finally, there are examples that do not exhibit similarities to any of the aforementioned categories. Moreover, the vast majority of invertebrate lectins described so far cannot yet be placed in one or another group because of the lack of information regarding their primary structure. (See Table 1.) Animal lectins do not express a recombinatorial diversity like that of antibodies, but a limited diversity in recognition capabilities would be accomplished by the occurrence of multiple lectins with distinct specificities, the presence of more than one binding site, specific for different carbohydrates in a single molecule, and by certain "flexibility" of the binding sites that would allow the recognition of a range of structurally related carbohydrates. In order to identify the lectins' "natural" ligands, we have investigated the interactions between those proteins and the putative endogenous or exogenous glycosylated substances or cells that may be relevant to their biological function. Results from these studies, together with information on the biochemical properties of invertebrate and vertebrate lectins, including their structural

  11. Non-canonical roles of tRNAs and tRNA mimics in bacterial cell biology.

    Science.gov (United States)

    Katz, Assaf; Elgamal, Sara; Rajkovic, Andrei; Ibba, Michael

    2016-08-01

    Transfer RNAs (tRNAs) are the macromolecules that transfer activated amino acids from aminoacyl-tRNA synthetases to the ribosome, where they are used for the mRNA guided synthesis of proteins. Transfer RNAs are ancient molecules, perhaps even predating the existence of the translation machinery. Albeit old, these molecules are tremendously conserved, a characteristic that is well illustrated by the fact that some bacterial tRNAs are efficient and specific substrates of eukaryotic aminoacyl-tRNA synthetases and ribosomes. Considering their ancient origin and high structural conservation, it is not surprising that tRNAs have been hijacked during evolution for functions outside of translation. These roles beyond translation include synthetic, regulatory and information functions within the cell. Here we provide an overview of the non-canonical roles of tRNAs and their mimics in bacteria, and discuss some of the common themes that arise when comparing these different functions.

  12. The 3' to 5' Exoribonuclease DIS3: From Structure and Mechanisms to Biological Functions and Role in Human Disease

    Directory of Open Access Journals (Sweden)

    Sophie R. Robinson

    2015-07-01

    Full Text Available DIS3 is a conserved exoribonuclease and catalytic subunit of the exosome, a protein complex involved in the 3' to 5' degradation and processing of both nuclear and cytoplasmic RNA species. Recently, aberrant expression of DIS3 has been found to be implicated in a range of different cancers. Perhaps most striking is the finding that DIS3 is recurrently mutated in 11% of multiple myeloma patients. Much work has been done to elucidate the structural and biochemical characteristics of DIS3, including the mechanistic details of its role as an effector of RNA decay pathways. Nevertheless, we do not understand how DIS3 mutations can lead to cancer. There are a number of studies that pertain to the function of DIS3 at the organismal level. Mutant phenotypes in S. pombe, S. cerevisiae and Drosophila suggest DIS3 homologues have a common role in cell-cycle progression and microtubule assembly. DIS3 has also recently been implicated in antibody diversification of mouse B-cells. This article aims to review current knowledge of the structure, mechanisms and functions of DIS3 as well as highlighting the genetic patterns observed within myeloma patients, in order to yield insight into the putative role of DIS3 mutations in oncogenesis.

  13. HIV Infection among Young People in Northwest Tanzania: The Role of Biological, Behavioural and Socio-Demographic Risk Factors.

    Directory of Open Access Journals (Sweden)

    Francesca Lemme

    Full Text Available Young people are at high risk of HIV and developing appropriate prevention programmes requires an understanding of the risk factors for HIV in this age group. We investigated factors associated with HIV among participants aged 15-30 years in a 2007-8 cross-sectional survey nested within a community-randomised trial of the MEMA kwa Vijana intervention in 20 rural communities in northwest Tanzania.We analysed data for 7259(53% males and 6476(47% females. Using a proximate-determinant conceptual framework and conditional logistic regression, we obtained sex-specific Odds Ratios (ORs for the association of HIV infection with socio-demographic, knowledge, behavioural and biological factors.HSV-2 infection was strongly associated with HIV infection (females: adjOR 4.4, 95%CI 3.2-6.1; males: adjOR 4.2, 95%CI 2.8-6.2. Several socio-demographic factors (such as age, marital status and mobility, behavioural factors (condom use, number and type of sexual partnerships and biological factors (blood transfusion, lifetime pregnancies, genital ulcers, Neisseria gonorrhoeae were also associated with HIV infection. Among females, lifetime sexual partners (linear trend, p<0.001, ≥2 partners in the past year (adjOR 2.0, 95%CI 1.4-2.8, ≥2 new partners in the past year (adjOR 1.9 95%CI 1.2, 3.3 and concurrent partners in the past year (adjOR 1.6 95%CI 1.1, 2.4 were all associated with HIV infection.Efforts must be intensified to find effective interventions to reduce HSV-2. Effective behavioural interventions focusing on reducing the number of sexual partnerships and risk behaviour within partnerships are also needed. An increase in risky sexual behaviour may occur following marriage dissolution or when a young woman travels outside of her community and interventions addressing the needs of these subgroups of vulnerable women may be important.ClinicalTrial.gov NCT00248469.

  14. Low dose/low fluence ionizing radiation-induced biological effects: The role of intercellular communication and oxidative metabolism

    Science.gov (United States)

    Azzam, Edouard

    Mechanistic investigations have been considered critical to understanding the health risks of exposure to ionizing radiation. To gain greater insight in the biological effects of exposure to low dose/low fluence space radiations with different linear energy transfer (LET) properties, we examined short and long-term biological responses to energetic protons and high charge (Z) and high energy (E) ions (HZE particles) in human cells maintained in culture and in targeted and non-targeted tissues of irradiated rodents. Particular focus of the studies has been on mod-ulation of gene expression, proliferative capacity, induction of DNA damage and perturbations in oxidative metabolism. Exposure to mean doses of 1000 MeV/nucleon iron ions, by which a small to moderate proportion of cells in an exposed population is targeted through the nucleus by an HZE particle, induced stressful effects in the irradiated and non-irradiated cells in the population. Direct intercellular communication via gap-junctions was a primary mediator of the propagation of stressful effects from irradiated to non-irradiated cells. Compromised prolif-erative capacity, elevated level of DNA damage and oxidative stress evaluated by measurements of protein carbonylation, lipid peroxidation and activity of metabolic enzymes persisted in the progeny of irradiated and non-irradiated cells. In contrast, progeny of cells exposed to high or low doses from 150-1000 MeV protons retained the ability to form colonies and harbored similar levels of micronuclei, a surrogate form of DNA damage, as control, which correlated with normal reactive oxygen species (ROS) levels. Importantly, a significant increase in the spontaneous neoplastic transformation frequency was observed in progeny of bystander mouse embryo fibroblasts (MEFs) co-cultured with MEFs irradiated with energetic iron ions but not protons. Of particular significance, stressful effects were detected in non-targeted tissues of rats that received partial

  15. The role of pattern recognition in creative problem solving: a case study in search of new mathematics for biology.

    Science.gov (United States)

    Hong, Felix T

    2013-09-01

    Rosen classified sciences into two categories: formalizable and unformalizable. Whereas formalizable sciences expressed in terms of mathematical theories were highly valued by Rutherford, Hutchins pointed out that unformalizable parts of soft sciences are of genuine interest and importance. Attempts to build mathematical theories for biology in the past century was met with modest and sporadic successes, and only in simple systems. In this article, a qualitative model of humans' high creativity is presented as a starting point to consider whether the gap between soft and hard sciences is bridgeable. Simonton's chance-configuration theory, which mimics the process of evolution, was modified and improved. By treating problem solving as a process of pattern recognition, the known dichotomy of visual thinking vs. verbal thinking can be recast in terms of analog pattern recognition (non-algorithmic process) and digital pattern recognition (algorithmic process), respectively. Additional concepts commonly encountered in computer science, operations research and artificial intelligence were also invoked: heuristic searching, parallel and sequential processing. The refurbished chance-configuration model is now capable of explaining several long-standing puzzles in human cognition: a) why novel discoveries often came without prior warning, b) why some creators had no ideas about the source of inspiration even after the fact, c) why some creators were consistently luckier than others, and, last but not least, d) why it was so difficult to explain what intuition, inspiration, insight, hunch, serendipity, etc. are all about. The predictive power of the present model was tested by means of resolving Zeno's paradox of Achilles and the Tortoise after one deliberately invoked visual thinking. Additional evidence of its predictive power must await future large-scale field studies. The analysis was further generalized to constructions of scientific theories in general. This approach

  16. The Role of Biological Agents and Immunomodulators in Treatment Strategies for Thyroid Eye Disease: An Evidence-based Review.

    Science.gov (United States)

    Ginter, Anna; Migliori, Michael E

    2016-06-01

    Graves' Disease is an autoimmune disease where circulating antibodies bind to the thyrotropin receptors on the thyroid gland. These bound antibodies mimic thyroid stimulating hormone without the normal feedback from the anterior pituitary, causing hyperthyroidism and thyrotoxicosis. These antibodies also interact with orbital tissues and cause the characteristic orbital findings of thyroid eye disease (TED). It is not clearly understood why anatomically and physiologically distinct tissues like the thyroid gland and orbit are affected selectively, or why the orbital disease tends to be self-limited. Identifying and understanding these processes is critical to targeting therapy. In the active phase of the disease patients may experience orbital inflammation, eyelid and conjunctiva edema (chemosis), eyelid retraction, proptosis, ocular motility restriction, and optic nerve compression. Current treatment strategies for the ocular symptoms have been predominantly directed at symptomatic relief. More recently, investigators have concentrated their efforts to better understanding the underlying pathophysiologic processes to direct therapy at these processes. This review examines the current literature exploring a variety of newer therapeutic alternatives, including immunomodulative and suppressive agents, targeted at strategic points of the active-phase TED pathophysiological pathways. Specifically, biological agents including rituximab, adalimumab, intravenous immunoglobulin and others are reviewed with considerations for pathophysiology, extent of literature support, and adverse effects. [Full article available at http://rimed.org/rimedicaljournal-2016-06.asp, free with no login].

  17. Fractal structures of single-walled carbon nanotubes in biologically relevant conditions: role of chirality vs. media conditions.

    Science.gov (United States)

    Khan, Iftheker A; Aich, Nirupam; Afrooz, A R M Nabiul; Flora, Joseph R V; Schierz, P Ariette; Ferguson, P Lee; Sabo-Attwood, Tara; Saleh, Navid B

    2013-11-01

    Aggregate structure of covalently functionalized chiral specific semiconducting single-walled carbon nanotubes (SWNTs) was systematically studied employing static light scattering (SLS). Fractal dimensions (Df) of two specific chirality SWNTs-SG65 and SG76 with (6, 5) and (7, 6) chiral enrichments-were measured under four biological exposure media conditions, namely: Dulbecco's Modified Eagle Medium (DMEM), Minimum Essential Medium (MEM), Roswell Park Memorial Institute (RPMI) 1640 medium, and 0.9% saline solution. The SWNTs exhibited chiral dependence on Df with SG65 showing more fractal or loosely bound aggregate structures, i.e., lower Df values (range of 2.24±0.03 to 2.64±0.05), compared to the SG76 sample (range of 2.58±0.13 to 2.90±0.08). All the Df values reported are highly reproducible, measured from multiple SLS runs and estimated with 'random block-effects' statistical analysis that yielded all p values to be fractal aggregates. Moreover, presence of fetal bovine serum (FBS) and bovine serum albumin (BSA), used to mimic the in vitro cell culture condition, reduced the Df values, i.e., created more fractal structures. Steric hindrance to aggregation was identified as the key mechanism for creating the fractal structures. Also, increase in FBS concentration from 1% to 10% resulted in increasingly lower Df values.

  18. Assessment of crude glycerol for Enhanced Biological Phosphorus Removal: Stability and role of long chain fatty acids.

    Science.gov (United States)

    Tayà, Carlota; Guerrero, Javier; Suárez-Ojeda, María Eugenia; Guisasola, Albert; Baeza, Juan Antonio

    2015-12-01

    Enhanced Biological Phosphorus Removal (EBPR) of urban wastewaters is usually limited by the available carbon source required by Polyphosphate Accumulating Organisms (PAO). External carbon sources as volatile fatty acids (VFA) or other pure organic compounds have been tested at lab scale demonstrating its ability to enhance PAO activity, but the application of this strategy at full-scale WWTPs is not cost-effective. The utilization of industrial by-products with some of these organic compounds provides lower cost, but it has the possible drawback of having inhibitory or toxic compounds to PAO. This study is focused on the utilization of crude glycerol, the industrial by-product generated in the biodiesel production, as a possible carbon source to enhance EBPR in carbon-limited urban wastewaters. Crude glycerol has non-negligible content of other organic compounds as methanol, salts, VFA and long chain fatty acids (LCFA). VFA and methanol have been demonstrated to enhance PAO activity, but there is no previous study about the effect of LCFA on PAO. This work presents the operation of an EBPR SBR system using crude glycerol as sole carbon source, studying also its long-term stability. The effect of LCFA is evaluated at short and long-term operation, demonstrating for the first time EBPR activity with LCFA as sole carbon source and its long-term failure due to the increased hydrophobicity of the sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Understanding the Biological Roles of Pectins in Plants through Physiological and Functional Characterizations of Plant and Fungal Mutants

    DEFF Research Database (Denmark)

    Stranne, Maria

    wall acetylation (Chapter 2), identification of a candidate gene required for acetylation of pectin (Chapter 3), screening of pectin mutants for susceptibility to the nectrotrophic fungal pathogen Botrytis cinerea (Chapter 4), and identification and functional characterization of an arabinan......-degrading enzyme secreted by B. cinerea during infection of plants (Chapter 5). The results described resulted in valuable new knowledge regarding the role of pectin acetylation and arabinosylation in the model plant Arabidopsis thaliana documented in three published research papers, one manuscript and one...

  20. HER3 comes of age: new insights into its functions and role in signaling, tumor biology, and cancer therapy.

    Science.gov (United States)

    Campbell, Marcia R; Amin, Dhara; Moasser, Mark M

    2010-03-01

    The human epidermal growth family (HER) of tyrosine kinase receptors underlies the pathogenesis of many types of human cancer. The oncogenic functions of three of the HER proteins can be unleashed through amplification, overexpression, or mutational activation. This has formed the basis for the development of clinically active targeted therapies. However, the third member HER3 is catalytically inactive, not found to be mutated or amplified in cancers, and its role and functions have remained shrouded in mystery. Recent evidence derived primarily from experimental models now seems to implicate HER3 in the pathogenesis of several types of cancer. Furthermore, the failure to recognize the central role of HER3 seems to underlie resistance to epidermal growth factor receptor (EGFR)- or HER2-targeted therapies in some cancers. Structural and biochemical studies have now greatly enhanced our understanding of signaling in the HER family and revealed the previously unrecognized activating functions embodied in the catalytically impaired kinase domain of HER3. This renewed interest and mechanistic basis has fueled the development of new classes of HER3-targeting agents for cancer therapy. However, identifying HER3-dependent tumors presents a formidable challenge and the success of HER3-targeting approaches depends entirely on the development and power of predictive tools.

  1. 表达HPV16L1、L2和E7蛋白的非复制重组痘苗病毒的构建%Construction of non-replicating recombinant vaccinia virus expressing HPV16 L1, L2E7 proteins

    Institute of Scientific and Technical Information of China (English)

    Jiangtao Fan; Xinqiu Chen; Wei Huang; Houwen Tian

    2009-01-01

    Objective:To construct a non-replicating vaccinia virus expressing human papitlomavirus 16 (HPV16) L1, L2E7 proteins as a candidate vaccine for cervical cancer. Methods:Using vaccinia virus vector, we generated a strain of non-repli-cating recombinant vaccinia virus vaccine expressing HPV16 L1, L2E7 proteins by homologous recombination and identified by PCR and Western-bloting. Results:We demonstrated that the L1, L2E7 gene of HPV16 were integrated into vaccinia genosome and could express L1, L2E7 protein stably when infected the CEF using PCR and Western-blot assay. Conclu-sion:NTVJL1/L2E7 can express L1, L2E7 protein of HPV16 and can be taken as a candidate vaccine for HPV16-associated diseases.

  2. A Novel Biological Role of α-Mangostin in Modulating Inflammatory Response Through the Activation of SIRT-1 Signaling Pathway.

    Science.gov (United States)

    Franceschelli, Sara; Pesce, Mirko; Ferrone, Alessio; Patruno, Antonia; Pasqualone, Livia; Carlucci, Giuseppe; Ferrone, Vincenzo; Carlucci, Maura; de Lutiis, Maria Anna; Grilli, Alfredo; Felaco, Mario; Speranza, Lorenza

    2016-11-01

    Several studies have shown that xanthones obtained from Garcinia Mangostana (GM) have remarkable biological activities. α-mangostin (α-MG) is the main constituent of the fruit hull of the GM. Several findings have suggested that SIRT-1, a nuclear histone deacetylase, could influence cellular function by the inhibition of NF-kB signaling. ROS can inhibit SIRT-1 activity by initiating oxidative modifications on its cysteine residues, and suppression of SIRT-1 enhances the NF-κB signaling resulting in inflammatory responses. The goals of the present study were to evaluate the quantity of α-MG in the methanolic extract of GM (Vithagroup Spa) and to investigate the activity of this xanthone in U937 cell line and in human monocytes from responsive to inflammatory insult analyzing the possible changes on the activation of SIRT-1 protein via NF-Kb. Cells were treated with the methanolic extract of GM and/or LPS. The chromatographic separation of α-MG was performed by an HPLC analysis. EX 527, a specific SIRT-1 inhibitor, was used to determine if SIRT-1/NfkB signaling pathway might be involved in α-MG action on cells. Our results show that α-MG inhibits p65 acetylation and down-regulates the pro-inflammatory gene products as COX-2, iNOS via SIRT-1 activation. Cells treated with EX 527 showed an up-regulation of NFkB acetylation and an over expression of inducible enzymes and their product of catalysis (NO and PGE2). These results suggest that α-MG may be useful for the development of alternative pharmacological strategies aimed at reducing the inflammatory process. J. Cell. Physiol. 231: 2439-2451, 2016. © 2016 Wiley Periodicals, Inc.

  3. Pollination biology of fruit-bearing hedgerow plants and the role of flower-visiting insects in fruit-set.

    Science.gov (United States)

    Jacobs, Jennifer H; Clark, Suzanne J; Denholm, Ian; Goulson, Dave; Stoate, Chris; Osborne, Juliet L

    2009-12-01

    In the UK, the flowers of fruit-bearing hedgerow plants provide a succession of pollen and nectar for flower-visiting insects for much of the year. The fruits of hedgerow plants are a source of winter food for frugivorous birds on farmland. It is unclear whether recent declines in pollinator populations are likely to threaten fruit-set and hence food supply for birds. The present study investigates the pollination biology of five common hedgerow plants: blackthorn (Prunus spinosa), hawthorn (Crataegus monogyna), dog rose (Rosa canina), bramble (Rubus fruticosus) and ivy (Hedera helix). The requirement for insect pollination was investigated initially by excluding insects from flowers by using mesh bags and comparing immature and mature fruit-set with those of open-pollinated flowers. Those plants that showed a requirement for insect pollination were then tested to compare fruit-set under two additional pollination service scenarios: (1) reduced pollination, with insects excluded from flowers bagged for part of the flowering period, and (2) supplemental pollination, with flowers hand cross-pollinated to test for pollen limitation. The proportions of flowers setting fruit in blackthorn, hawthorn and ivy were significantly reduced when insects were excluded from flowers by using mesh bags, whereas fruit-set in bramble and dog rose were unaffected. Restricting the exposure of flowers to pollinators had no significant effect on fruit-set. However, blackthorn and hawthorn were found to be pollen-limited, suggesting that the pollination service was inadequate in the study area. Ensuring strong populations of insect pollinators may be essential to guarantee a winter fruit supply for birds in UK hedgerows.

  4. Study and reflections on the functional and organizational role of neuromessenger nitric oxide in learning: An artificial and biological approach

    Science.gov (United States)

    Suárez Araujo, C. P.

    2000-05-01

    We present in this work a theoretical and conceptual study and some reflections on a fundamental aspect concerning with the structure and brain function: the Cellular Communication. The main interests of our study are the signal transmission mechanisms and the neuronal mechanisms responsible to learning. We propose the consideration of a new kind of communication mechanisms, different to the synaptic transmission, "Diffusion or Volume Transmission." This new alternative is based on a diffusing messenger as nitric oxide (NO). Our study aims towards the design of a conceptual framework, which covers implications of NO in the artificial neural networks (ANNs), both in neural architecture and learning processing. This conceptual frame might be able to provide possible biological support for many aspects of ANNs and to generate new concepts to improve the structure and operation of them. Some of these new concepts are The Fast Diffusion Neural Propagation (FDNP), the Diffuse Neighborhood (DNB), (1), the Diffusive Hybrid Neuromodulation (DHN), the Virtual Weights. Finally we will propose a new mathematical formulation for the Hebb learning law, taking into account the NO effect. Along the same lines, we will reflect on the possibility of a new formal framework for learning processes in ANNs, which consist of slow and fast learning concerning with co-operation between the classical neurotransmission and FDNP. We will develop this work from a computational neuroscience point of view, proposing a global study framework of diffusion messenger NO (GSFNO), using a hybrid natural/artificial approach. Finally it is important to note that we can consider this paper the first paper of a set of scientific work on nitric oxide (NO) and artificial neural networks (ANNs): NO and ANNs Series. We can say that this paper has a character of search and query on both subjects their implications and co-existence.

  5. Physical biology in cancer. 3. The role of cell glycocalyx in vascular transport of circulating tumor cells.

    Science.gov (United States)

    Mitchell, Michael J; King, Michael R

    2014-01-15

    Circulating tumor cells (CTCs) in blood are known to adhere to the luminal surface of the microvasculature via receptor-mediated adhesion, which contributes to the spread of cancer metastasis to anatomically distant organs. Such interactions between ligands on CTCs and endothelial cell-bound surface receptors are sensitive to receptor-ligand distances at the nanoscale. The sugar-rich coating expressed on the surface of CTCs and endothelial cells, known as the glycocalyx, serves as a physical structure that can control the spacing and, thus, the availability of such receptor-ligand interactions. The cancer cell glycocalyx can also regulate the ability of therapeutic ligands to bind to CTCs in the bloodstream. Here, we review the role of cell glycocalyx on the adhesion and therapeutic treatment of CTCs in the bloodstream.

  6. STUDY OF TENASCIN-C (TN-C PROTEIN ROLE IN ORAL MALIGNANCY PROGRESSIVITY PROCESS BY MOLECULAR BIOLOGICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Into Suhardjo

    2006-04-01

    Full Text Available The progressiveness of malignant tumors influenced by various complex factors. One of the important factors is Tenascin-C (Tn-C protein, which can interact with fibrinectin as an anti adhesive or anti modulation protein. Tenascin-C is an extra cellular matrix glycoprotein (EMG, which can be found in the oral tissue also as an up regulator. They can be associated with EMG, and strongly influenced promotion of the stromal cell as cell growth, migration, differentiation, angiogenesis, and apoptosis in cancer. Alternative splicing of fibronectin-like type III (FN III repeats of Tn-C generates a number of splice variants, and influences tumor progressiveness. The conclusion of Tn-C role in tumor progressiveness depends on the molecular weight and alternative splicing of FN III.

  7. Characterization and quantification of the role of coherence in ultrafast quantum biological experiments using quantum master equations, atomistic simulations, and quantum process tomography

    CERN Document Server

    Rebentrost, Patrick; Yuen-Zhou, Joel; Aspuru-Guzik, Alán

    2010-01-01

    Long-lived electronic coherences in various photosynthetic complexes at cryogenic and room temperature have generated vigorous efforts both in theory and experiment to understand their origins and explore their potential role to biological function. The ultrafast signals resulting from the experiments that show evidence for these coherences result from many contributions to the molecular polarization. Quantum process tomography (QPT) was conceived in the context of quantum information processing to characterize and understand general quantum evolution of controllable quantum systems, for example while carrying out quantum computational tasks. We introduce our QPT method for ultrafast experiments, and as an illustrative example, apply it to a simulation of a two-chromophore subsystem of the Fenna-Matthews-Olson photosynthetic complex, which was recently shown to have long-lived quantum coherences. Our Fenna-Matthews-Olson model is constructed using an atomistic approach to extract relevant parameters for the s...

  8. The role of the chi1 gene from the endophytic bacteria Serratia proteamaculans 336x in the biological control of wheat take-all.

    Science.gov (United States)

    Wang, Miao; Xing, Yuwan; Wang, Junfang; Xu, Yubin; Wang, Gang

    2014-08-01

    Take-all, a disease caused by the fungus Gaeumannomyces graminis var. tritici, is the most important root disease of wheat and causes severe yield losses worldwide. Using microorganisms as biological agents to control the disease is important because no resistant cultivars or effective chemical fungicides are available. In this study, we tested the biological control capability of a chitinase produced by the endophytic bacterium Serratia proteamaculans 336x against wheat take-all. The chitinase gene chi1 of S. proteamaculans 336x was cloned and heterologously expressed in Escherichia coli. The recombinant protein exhibited chitinase activity and in vitro antifungal activity against G. graminis var. tritici. With in-frame deletion of the chi1 gene by homologous recombination, the chi1-deleted mutant was devoid of chitinase activity and the biocontrol efficacy was reduced by 42.5%. The complementation of the Δchi1 mutant strain by the chi1 gene resulted in the partial restoration of the chitinase activity and biocontrol efficacy. These results support a role for the Chi1 protein in the biocontrol process of S. proteamaculans 336x against wheat take-all.

  9. Biological Activity of Mesoporous Dendrimer-Coated Titanium Dioxide: Insight on the Role of the Surface-Interface Composition and the Framework Crystallinity.

    Science.gov (United States)

    Milowska, Katarzyna; Rybczyńska, Aneta; Mosiolek, Joanna; Durdyn, Joanna; Szewczyk, Eligia M; Katir, Nadia; Brahmi, Younes; Majoral, Jean-Pierre; Bousmina, Mosto; Bryszewska, Maria; El Kadib, Abdelkrim

    2015-09-16

    Hitherto, the field of nanomedicine has been overwhelmingly dominated by the use of mesoporous organosilicas compared to their metal oxide congeners. Despite their remarkable reactivity, titanium oxide-based materials have been seldom evaluated and little knowledge has been gained with respect to their "structure-biological activity" relationship. Herein, a fruitful association of phosphorus dendrimers (both "ammonium-terminated" and "phosphonate-terminated") and titanium dioxide has been performed by means of the sol-gel process, resulting in mesoporous dendrimer-coated nanosized crystalline titanium dioxide. A similar organo-coating has been reproduced using single branch-mimicking dendrimers that allow isolation of an amorphous titanium dioxide. The impact of these materials on red blood cells was evaluated by studying cell hemolysis. Next, their cytotoxicity toward B14 Chinese fibroblasts and their antimicrobial activity were also investigated. Based on their variants (cationic versus anionic terminal groups and amorphous versus crystalline titanium dioxide phase), better understanding of the role of the surface-interface composition and the nature of the framework has been gained. No noticeable discrimination was observed for amorphous and crystalline material. In contrast, hemolysis and cytotoxicity were found to be sensitive to the nature of the interface composition, with the ammonium-terminated dendrimer-coated titanium dioxide being the most hemolytic and cytotoxic material. This surface-functionalization opens the door for creating a new synergistic machineries mechanism at the cellular level and seems promising for tailoring the biological activity of nanosized organic-inorganic hybrid materials.

  10. The role of G protein coupled receptor-mediated signaling in the biological properties of Acanthamoeba castellanii of the T4 genotype.

    Science.gov (United States)

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Manan, Zainab; Khan, Naveed Ahmed

    2015-04-01

    Despite advances in antimicrobial chemotherapy and supportive care, the prognosis of Acanthamoeba infections remains poor, suggesting that new targets are needed that can affect parasite survival and host-pathogen interactions. G proteins and their coupled receptors are well known regulators of a variety of cellular functions. The overall aim of the present study was to study the role of G-protein coupled receptor, β adrenergic receptor on the biology and pathogenesis of keratitis isolate of Acanthamoeba castellanii of the T4 genotype. Inhibition of β adrenergic receptor using antagonist, propranolol had detrimental effects on the extracellular proteolytic activities A. castellanii as determined using zymographic assays. Conversely, β adrenergic receptor agonist, isoprenaline showed increased proteases. Interestingly, β adrenergic receptor inhibition affected A. castellanii growth (using amoebistatic assays), viability (using amoebicidal assays by measuring uptake of Trypan blue) and encystation as determined by trophozoite transformation into the cyst form. Pre-treatment of parasites with propranolol hampered A. castellanii-mediated human brain microvascular endothelial cell cytotoxicity, as measured by the lacatate dehydrogenase release. The aforementioned findings suggest that G-protein coupled receptor, β adrenergic receptor-mediated signaling in A. castellanii biology and pathogenesis may offer new pharmacological targets.

  11. Dual nitrate isotopes clarify the role of biological processing and hydrologic flow paths on nitrogen cycling in subtropical low-gradient watersheds

    Science.gov (United States)

    Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; Klaus, Julian; Du, Enhao; Bitew, Menberu M.

    2016-02-01

    Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds, while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. Together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.

  12. Ecosystem dynamics in the Liguro-Provençal Basin: the role of eddies in the biological production.

    Directory of Open Access Journals (Sweden)

    E. CASELLA

    2014-07-01

    Full Text Available We study numerically the role of mesoscale structures in the Ligurian Sea (NW Mediterranean Sea as a possible factor affecting the spatial distribution of the chlorophyll spring bloom. We use the Regional Ocean Modeling System (ROMS configured for the NW Mediterranean Sea (ROMS_NWMed and satellite derived Altimetric, Sea Surface Temperature and Chlorophyll concentration data, for years 2009 and 2010. Comparison of model output with satellite and in situ data shows agreement between numerical results and observations. There is a significant interannual variability in concentration and distribution of chlorophyll in the basin during the two years of the study. The ROMS_NWMed simulation reveals the formation of a number of mesoscale eddies along the Northern rim Current characterized by a long lifetime and closed streamlines. A significant higher number of eddies is found during the chlorophyll-rich year 2010. The high number of eddies, due to the “eddy pumping mechanism”, generate spatially and temporally localised fluxes of nutrient into the euphotic zone, thus contributing to the fertilization of the Ligurian Sea. Therefore, eddies in the Ligurian rim current can have important effects on the location of development of the main patch of chlorophyll spring bloom and consequently on the local ecosystem dynamics.

  13. New roles of flavoproteins in molecular cell biology: blue-light active flavoproteins studied by electron paramagnetic resonance.

    Science.gov (United States)

    Schleicher, Erik; Bittl, Robert; Weber, Stefan

    2009-08-01

    Exploring enzymatic mechanisms at a molecular level is one of the major challenges in modern biophysics. Based on enzyme structure data, as obtained by X-ray crystallography or NMR spectroscopy, one can suggest how substrates and products bind for catalysis. However, from the 3D structure alone it is very rarely possible to identify how intermediates are formed and how they are interconverted. Molecular spectroscopy can provide such information and thus supplement our knowledge on the specific enzymatic reaction under consideration. In the case of enzymatic processes in which paramagnetic molecules play a role, EPR and related methods such as electron-nuclear double resonance (ENDOR) are powerful techniques to unravel important details, e.g. the electronic structure or the protonation state of the intermediate(s) carrying (the) unpaired electron spin(s). Here, we review recent EPR/ENDOR studies of blue-light active flavoproteins with emphasis on photolyases that catalyze the enzymatic repair of UV damaged DNA, and on cryptochrome blue-light photoreceptors that act in several species as central components of the circadian clock.

  14. An overview on the role of FLT3-tyrosine kinase receptor in acute myeloid leukemia: biology and treatment

    Directory of Open Access Journals (Sweden)

    Tiziana Grafone

    2012-04-01

    Full Text Available Hematopoiesis, the process by which the hematopoietic stem cells and progenitors differentiate into blood cells of various lineages, involves complex interactions of transcription factors that modulate the expression of downstream genes and mediate proliferation and differentiation signals. Despite the many controls that regulate hematopoiesis, mutations in the regulatory genes capable of promoting leukemogenesis may occur. The FLT3 gene encodes a tyrosine kinase receptor that plays a key role in controlling survival, proliferation and differentiation of hematopoietic cells. Mutations in this gene are critical in causing a deregulation of the delicate balance between cell proliferation and differentiation. In this review, we provide an update on the structure, synthesis and activation of the FLT3 receptor and the subsequent activation of multiple downstream signaling pathways. We also review activating FLT3 mutations that are frequently identified in acute myeloid leukemia, cause activation of more complex downstream signaling pathways and promote leukemogenesis. Finally, FLT3 has emerged as an important target for molecular therapy. We, therefore, report on some recent therapies directed against it.

  15. The 5 Alpha-Reductase Isozyme Family: A Review of Basic Biology and Their Role in Human Diseases

    Directory of Open Access Journals (Sweden)

    Faris Azzouni

    2012-01-01

    Full Text Available Despite the discovery of 5 alpha-reduction as an enzymatic step in steroid metabolism in 1951, and the discovery that dihydrotestosterone is more potent than testosterone in 1968, the significance of 5 alpha-reduced steroids in human diseases was not appreciated until the discovery of 5 alpha-reductase type 2 deficiency in 1974. Affected males are born with ambiguous external genitalia, despite normal internal genitalia. The prostate is hypoplastic, nonpalpable on rectal examination and approximately 1/10th the size of age-matched normal glands. Benign prostate hyperplasia or prostate cancer does not develop in these patients. At puberty, the external genitalia virilize partially, however, secondary sexual hair remains sparse and male pattern baldness and acne develop rarely. Several compounds have been developed to inhibit the 5 alpha-reductase isozymes and they play an important role in the prevention and treatment of many common diseases. This review describes the basic biochemical properties, functions, tissue distribution, chromosomal location, and clinical significance of the 5 alpha-reductase isozyme family.

  16. The role of environmental, virological and vector interactions in dictating biological transmission of arthropod-borne viruses by mosquitoes.

    Science.gov (United States)

    Kenney, Joan L; Brault, Aaron C

    2014-01-01

    Arthropod-borne viruses (arboviruses) are transmitted between vertebrate hosts and arthropod vectors. An inherently complex interaction among virus, vector, and the environment determines successful transmission of the virus. Once believed to be "flying syringes," recent advances in the field have demonstrated that mosquito genetics, microbiota, salivary components, and mosquito innate immune responses all play important roles in modulating arbovirus transmissibility. The literature on the interaction among virus, mosquito, and environment has expanded dramatically in the preceding decade and the utilization of next-generation sequencing and transgenic vector methodologies assuredly will increase the pace of knowledge acquisition in this field. This chapter outlines the interplay among the three factors in both direct physical and biochemical manners as well as indirectly through superinfection barriers and altered induction of innate immune responses in mosquito vectors. The culmination of the aforementioned interactions and the arms race between the mosquito innate immune response and the capacity of arboviruses to antagonize such a response ultimately results in the subjugation of mosquito cells for viral replication and subsequent transmission.

  17. Biological interactions and their role in community structure in the rocky intertidal of Helgoland (German Bight, North Sea)

    Science.gov (United States)

    Janke, Klaus

    1990-06-01

    of F. serratus, herbivores such as L. littorea and L. mariae, and increasing number of predators such as Carcinus), the feeding activity of herbivores can neither prevent the settlement of the fucoid sporelings nor reduce the growth of macroalgae. F. serratus achieved a total canopy on the rock within one year. Doubled density of herbivores prevented the settlement of Fucus and most of the undercover algae. Predation by Carcinus on Littorina spp. had little influence on the herbivore community patterns. However, the crabs supported the establishment of macroalgae by excluding the mussels from the lower intertidal. In summary, the community organization and maintenance in the mid and lower intertidal is influenced to a high degree by biological interactions. Whereas both the relatively important herbivory by L. littorea and competition for space between mussels and macroalgae dominate in the mid intertidal, predation reaches its highest relative degree of importance for community structure in the lower intertidal.

  18. The role of intercellular communication and oxidative metabolism in the propagation of ionizing radiation-induced biological effects

    Science.gov (United States)

    Autsavapromporn, Narongchai

    Coordinated interactions of specific molecular and biochemical processes are likely involved in the cellular responses to stresses induced by different ionizing radiations with distinctive linear energy transfer (LET) properties. Here, we investigated the roles and mechanisms of gap junction intercellular communication and oxidative metabolism in modulating cell killing and repair of potentially lethal damage (PLDR) in confluent AG1522 human fibroblasts exposed to 1 GeV protons (LET˜0.2 keV/μm), 137Cs γ rays (LET˜0.9 keV/μm), 241Am α particles (LET˜122 keV/μm) or 1 GeV/u iron ions (LET˜151 keV/μm) at doses by which all cells in the exposed cultures are irradiated. As expected, α-particles and iron ions were more effective than protons and γ rays at inducing cell killing. Holding γ- or proton-irradiated cells in the confluent state for several hours after irradiation promoted increased survival and decreased chromosomal damage. However, maintaining α-particle or iron ion-irradiated cells in the confluent state for various times prior to subculture resulted in increased rather than decreased lethality, and was associated with. persistent DNA damage and increased protein oxidation and lipid peroxidation. Inhibiting gap junction communication with 18-α-glycyrrhetinic acid or by knockdown of connexin43, a constitutive protein of junctional channels in these cells, protected against the toxic effects expressed in these cells during confluent holding. Up-regulation of antioxidant defense by ectopic over-expression of glutathione peroxidase, protected against cell killing by α-particles when cells were analyzed shortly after exposure. However, it did not attenuate the decrease in survival during confluent holding. Together, these findings indicate that the damaging effect of α particles results in oxidative stress, and the toxic effects in the hours following irradiation are amplified by intercellular communication, but the communicated molecule(s) is

  19. Biological roles of nontypeable Haemophilus influenzae type IV pilus proteins encoded by the pil and com operons.

    Science.gov (United States)

    Carruthers, Michael D; Tracy, Erin N; Dickson, Amanda C; Ganser, Kara B; Munson, Robert S; Bakaletz, Lauren O

    2012-04-01

    We previously demonstrated that one or more products of the genes in the pil and com gene clusters of the opportunistic human respiratory pathogen nontypeable Haemophilus influenzae (NTHI) are required for type IV pilus (Tfp) biogenesis and function. Here, we have now demonstrated that the pilABCD and comABCDEF gene clusters are operons and that the product of each gene is essential for normal pilus function. Mutants with nonpolar deletions in each of the 10 pil and com genes had an adherence defect when primary human airway cells were used as the target. These mutants were also diminished in their ability to form a biofilm in vitro and, additionally, were deficient in natural transformation. Collectively, our data demonstrate that the product of each gene within these operons is required for the normal biogenesis and/or function of NTHI Tfp. Based on the similarity of PilA to other type IV pilins, we further predicted that the product of the pilA gene would be the major pilin subunit. Toward that end, we also demonstrated by immunogold labeling and mass spectrometry that PilA is indeed the majority type IV pilin protein expressed by NTHI. These new observations set the stage for experiments designed to dissect the function of each of the proteins encoded by genes within the pil and com gene clusters. The ability to characterize individual proteins with vital roles in NTHI colonization or pathogenesis has the potential to reduce the burden of NTHI-induced diseases through development of a Tfp-derived vaccine or a pilus-directed therapeutic.

  20. Biological roles of the Podospora anserina mitochondrial Lon protease and the importance of its N-domain.

    Directory of Open Access Journals (Sweden)

    Céline Adam

    Full Text Available Mitochondria have their own ATP-dependent proteases that maintain the functional state of the organelle. All multicellular eukaryotes, including filamentous fungi, possess the same set of mitochondrial proteases, unlike in unicellular yeasts, where ClpXP, one of the two matricial proteases, is absent. Despite the presence of ClpXP in the filamentous fungus Podospora anserina, deletion of the gene encoding the other matricial protease, PaLon1, leads to lethality at high and low temperatures, indicating that PaLON1 plays a main role in protein quality control. Under normal physiological conditions, the PaLon1 deletion is viable but decreases life span. PaLon1 deletion also leads to defects in two steps during development, ascospore germination and sexual reproduction, which suggests that PaLON1 ensures important regulatory functions during fungal development. Mitochondrial Lon proteases are composed of a central ATPase domain flanked by a large non-catalytic N-domain and a C-terminal protease domain. We found that three mutations in the N-domain of PaLON1 affected fungal life cycle, PaLON1 protein expression and mitochondrial proteolytic activity, which reveals the functional importance of the N-domain of the mitochondrial Lon protease. All PaLon1 mutations affected the C-terminal part of the N-domain. Considering that the C-terminal part is predicted to have an α helical arrangement in which the number, length and position of the helices are conserved with the solved structure of its bacterial homologs, we propose that this all-helical structure participates in Lon substrate interaction.

  1. Role of SPI-1 secreted effectors in acute bovine response to Salmonella enterica Serovar Typhimurium: a systems biology analysis approach.

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    Sara D Lawhon

    Full Text Available Salmonella enterica Serovar Typhimurium (S. Typhimurium causes enterocolitis with diarrhea and polymorphonuclear cell (PMN influx into the intestinal mucosa in humans and calves. The Salmonella Type III Secretion System (T3SS encoded at Pathogenicity Island I translocates Salmonella effector proteins SipA, SopA, SopB, SopD, and SopE2 into epithelial cells and is required for induction of diarrhea. These effector proteins act together to induce intestinal fluid secretion and transcription of C-X-C chemokines, recruiting PMNs to the infection site. While individual molecular interactions of the effectors with cultured host cells have been characterized, their combined role in intestinal fluid secretion and inflammation is less understood. We hypothesized that comparison of the bovine intestinal mucosal response to wild type Salmonella and a SipA, SopABDE2 effector mutant relative to uninfected bovine ileum would reveal heretofore unidentified diarrhea-associated host cellular pathways. To determine the coordinated effects of these virulence factors, a bovine ligated ileal loop model was used to measure responses to wild type S. Typhimurium (WT and a ΔsipA, sopABDE2 mutant (MUT across 12 hours of infection using a bovine microarray. Data were analyzed using standard microarray analysis and a dynamic bayesian network modeling approach (DBN. Both analytical methods confirmed increased expression of immune response genes to Salmonella infection and novel gene expression. Gene expression changes mapped to 219 molecular interaction pathways and 1620 gene ontology groups. Bayesian network modeling identified effects of infection on several interrelated signaling pathways including MAPK, Phosphatidylinositol, mTOR, Calcium, Toll-like Receptor, CCR3, Wnt, TGF-β, and Regulation of Actin Cytoskeleton and Apoptosis that were used to model of host-pathogen interactions. Comparison of WT and MUT demonstrated significantly different patterns of host response

  2. Evidence of the Role of R-Spondin 1 and Its Receptor Lgr4 in the Transmission of Mechanical Stimuli to Biological Signals for Bone Formation

    Science.gov (United States)

    Shi, Gui-Xun; Zheng, Xin-Feng; Zhu, Chao; Li, Bo; Wang, Yu-Ren; Jiang, Sheng-Dan; Jiang, Lei-Sheng

    2017-01-01

    The bone can adjust its mass and architecture to mechanical stimuli via a series of molecular cascades, which have been not yet fully elucidated. Emerging evidence indicated that R-spondins (Rspos), a family of secreted agonists of the Wnt/β-catenin signaling pathway, had important roles in osteoblastic differentiation and bone formation. However, the role of Rspo proteins in mechanical loading-influenced bone metabolism has never been investigated. In this study, we found that Rspo1 was a mechanosensitive protein for bone formation. Continuous cyclic mechanical stretch (CMS) upregulated the expression of Rspo1 in mouse bone marrow mesenchymal stem cells (BMSCs), while the expression of Rspo1 in BMSCs in vivo was downregulated in the bones of a mechanical unloading mouse model (tail suspension (TS)). On the other hand, Rspo1 could promote osteogenesis of BMSCs under CMS through activating the Wnt/β-catenin signaling pathway and could rescue the bone loss induced by mechanical unloading in the TS mice. Specifically, our results suggested that Rspo1 and its receptor of leucine-rich repeat containing G-protein-coupled receptor 4 (Lgr4) should be a novel molecular signal in the transmission of mechanical stimuli to biological signal in the bone, and this signal should be in the upstream of Wnt/β-catenin signaling for bone formation. Rspo1/Lgr4 could be a new potential target for the prevention and treatment of disuse osteoporosis in the future. PMID:28272338

  3. Biological roles of anti-GM1 antibodies in patients with Guillain-Barré syndrome for nerve growth factor signaling.

    Science.gov (United States)

    Tanaka, Toshifumi; Furutama, Daisuke; Sakai, Reiko; Fujita, Atsushi; Kimura, Fumiharu; Tagami, Muneyoshi; Ohsawa, Nakaaki; Hanafusa, Toshiaki

    2007-05-01

    To reveal the biological and pathological roles of anti-GM1 antibody in Guillain-Barré syndrome (GBS), we examined its effects on nerve growth factor (NGF) induced TrkA autophosphorylation (NGF-TrkA signaling) in PC12 cells, a sympathetic nerve cell line. The NGF-TrkA signaling is enhanced by exogenous GM1 ganglioside and this phenomenon is regarded as one of the functional aspects of GM1. The IgGs purified from patients' sera inhibited the NGF-TrkA signaling in GM1 pre-incubated PC12 cells. The degrees of inhibition by IgGs from patients paralleled their immunological reactivity to GM1. In addition, the IgGs also inhibited the neurite outgrowth of NGF-treated PC12 cells. Immunoglobulins in the rabbit sera, which were immunized by GM1, also caused a similar suppressive phenomenon. These results suggested that the anti-GM1 antibody could play roles in pathophysiology in anti-GM1 antibody positive GBS through interfering with the neurotrophic action of NGF and GM1 mediated signal modulation including NGF-TrkA signaling. It is suggested that the modulation of GM1 function is one important action of antibodies and could be one of the important mechanisms in GBS.

  4. Modification and biological role of histone%组蛋白修饰及其生物学效应

    Institute of Scientific and Technical Information of China (English)

    王维; 孟智启; 石放雄

    2012-01-01

    Histone is one of critical components of chromatin, which amino acid residues at the N-terminus can be co-valently modified. Histone modification (HM) can change the chromatin conformation and induce transcription or gene silencing. Not only can HM control gene expression, but also participate in cell division, cell apoptosis and memory formation by recruiting protein complex and affecting downstream proteins. HM can also have the impact on immune system and inflammatory reaction. In addition, lots of recent studies have indicated that histone code (or HM) is related to the CTD code, circadian clock and DNA repair, implying the significance of HM. The domains of protein complex can never be replaced, because they play a mediating role during the formation and deciphering of histone code, as well as the modification cascade and the recruitment of protein complex. Therefore, these domains are very important to comprehend the histone code. Because of the widespread use of analytical techniques, such as mass-spectrometry, new domains will be discovered. Herein, our review focuses on the basic concept, recent progress and hot points of the histone code study.%组蛋白是染色质的主要成分之一,其氨基端的氨基酸残基可以被共价修饰,进而改变染色质构型,导致转录激活或基因沉默.组蛋白修饰除了简单地调控基因表达,更在于它可以招募蛋白复合体,影响下游蛋白,从而参与细胞分裂、细胞凋亡和记忆形成,甚至影响免疫系统和炎症反应等.不仅如此,最近的研究表明,组蛋白修饰与CTD 密码、生物节律、DNA 修复之间也存在一定的联系.这些发现证明了组蛋白修饰的重要性.在组蛋白的密码形成与密码破译、修饰级联与招募蛋白质过程中,蛋白复合体的特殊结构域起到的中介作用都是无法替代的.因此,这些特殊结构域将是了解"组蛋白密码"的关键.目前质谱分析等技术的广泛应用,正使得许多新

  5. Is Our Biology to Blame?

    Science.gov (United States)

    Schneider, Scott

    1977-01-01

    Brief analyses of three recent examples of biological determinism: sex roles, overpopulation, and sociobiology, are presented in this article. Also a brief discussion of biological determinism and education is presented. (MR)

  6. Is Our Biology to Blame?

    Science.gov (United States)

    Schneider, Scott

    1977-01-01

    Brief analyses of three recent examples of biological determinism: sex roles, overpopulation, and sociobiology, are presented in this article. Also a brief discussion of biological determinism and education is presented. (MR)

  7. The role of differentiation and standards-based grading in the science learning of struggling and advanced learners in a detracked high school honors biology classroom

    Science.gov (United States)

    MacDonald, Michelina Ruth Carter

    The accountability movement in education resulting from the passage of The No Child Left Behind Act of 2001 has brought to light the disparities that exist in student achievement in the United States which play out along racial and socioeconomic lines. Three educational practices hold promise for reducing this achievement gap: differentiated instruction, standards-based assessment, and elimination of academic tracking. The purpose of this practitioner research study was to examine the ways that differentiation and standards-based assessment can support struggling learners and challenge advanced learners in a detracked, honors biology classroom. To gain insight into the role that differentiation and standards-based assessment played in supporting struggling and advanced learners, I used practitioner research to examine the development and implementation of a differentiated, standards-based instructional unit around the conceptual topic of protein synthesis. I collected multiple data pieces for 10 students in the study: two advanced learners, four struggling learners, and four strong learners who struggled in biology. Data analyzed included formative, self-, and summative assessment results; student artifacts; informal and formal student interviews; and, a practitioner reflection journal chronicling critical incidents and actions taken during the development and implementation of this unit and notes from peer debriefing during and following the unit's implementation. As I analyzed the data collected, my four findings fell into two overarching categories related to student grouping. My first three findings reflect what I learned about homogeneous grouping: (1) Pre-assessment based on unit outcomes is not useful for determining groups for tiered instruction; (2) Decisions about differentiation and grouping for differentiation must be made in the act of teaching using formative assessment results; and, (3) Flexible grouping structures are effective for both struggling

  8. All biology is computational biology.

    Science.gov (United States)

    Markowetz, Florian

    2017-03-01

    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science.

  9. All biology is computational biology

    Science.gov (United States)

    2017-01-01

    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science. PMID:28278152

  10. Zebrafish as a model for apolipoprotein biology: comprehensive expression analysis and a role for ApoA-IV in regulating food intake

    Directory of Open Access Journals (Sweden)

    Jessica P. Otis

    2015-03-01

    Full Text Available Improved understanding of lipoproteins, particles that transport lipids throughout the circulation, is vital to developing new treatments for the dyslipidemias associated with metabolic syndrome. Apolipoproteins are a key component of lipoproteins. Apolipoproteins are proteins that structure lipoproteins and regulate lipid metabolism through control of cellular lipid exchange. Constraints of cell culture and mouse models mean that there is a need for a complementary model that can replicate the complex in vivo milieu that regulates apolipoprotein and lipoprotein biology. Here, we further establish the utility of the genetically tractable and optically clear larval zebrafish as a model of apolipoprotein biology. Gene ancestry analyses were implemented to determine the closest human orthologs of the zebrafish apolipoprotein A-I (apoA-I, apoB, apoE and apoA-IV genes and therefore ensure that they have been correctly named. Their expression patterns throughout development were also analyzed, by whole-mount mRNA in situ hybridization (ISH. The ISH results emphasized the importance of apolipoproteins in transporting yolk and dietary lipids: mRNA expression of all apolipoproteins was observed in the yolk syncytial layer, and intestinal and liver expression was observed from 4–6 days post-fertilization (dpf. Furthermore, real-time PCR confirmed that transcription of three of the four zebrafish apoA-IV genes was increased 4 hours after the onset of a 1-hour high-fat feed. Therefore, we tested the hypothesis that zebrafish ApoA-IV performs a conserved role to that in rat in the regulation of food intake by transiently overexpressing ApoA-IVb.1 in transgenic larvae and quantifying ingestion of co-fed fluorescently labeled fatty acid during a high-fat meal as an indicator of food intake. Indeed, ApoA-IVb.1 overexpression decreased food intake by approximately one-third. This study comprehensively describes the expression and function of eleven zebrafish

  11. New insight on the biological role of p53 protein as a tumor suppressor: re-evaluation of its clinical significance in triple-negative breast cancer.

    Science.gov (United States)

    Jin, Min-Sun; Park, In Ae; Kim, Ji Young; Chung, Yul Ri; Im, Seock-Ah; Lee, Kyung-Hun; Moon, Hyeong-Gon; Han, Wonshik; Noh, Dong-Young; Ryu, Han Suk

    2016-08-01

    While p53 mutation is found in the majority of triple-negative breast cancer (TNBC) and despite recent developments in p53-targeting agents, their therapeutic application is still limited by the absence of standard biomarkers and ambiguousness of its essential biological role in cancer. Whole sections from 305 TNBC cases were stained for p53 to determine the correlation with lymph node metastasis and clinical outcomes in the whole cohort as well as in stratified patient groups according to AJCC stage and the use of adjuvant chemotherapy. Reduced immunohistochemical expression of p53 was an independent risk factor for lymph node metastasis. p53 overexpression was predictive of better clinical outcome in all patients (P = 0.012, disease-free survival and P = 0.008, overall survival) and the stratified cohorts of those who had early breast cancer and received adjuvant chemotherapy. Suppression of endogenous mutant p53 by siRNA and induction of wild-type p53 repressed TNBC cell invasion in vitro. In TNBC, increased immunohistochemical expression of p53 may reflect the accumulation of wild-type p53 rather than the mutant form. Strong p53 protein expression may serve as a favorable prognostic indicator and provide evidence for the use of specific agents targeting p53.

  12. Critical and distinct roles of amino- and carboxyl-terminal sequences in regulation of the biological activity of the Chp atypical Rho GTPase.

    Science.gov (United States)

    Chenette, Emily J; Abo, Arie; Der, Channing J

    2005-04-08

    Chp (Cdc42 homologous protein) shares significant sequence and functional identity with the human Cdc42 small GTPase, and like Cdc42, promotes formation of filopodia and activates the p21-activated kinase serine/threonine kinase. However, unlike Cdc42, Chp contains unique amino- and carboxyl-terminal extensions. Here we determined whether Chp, like Cdc42, can promote growth transformation and evaluated the role of the amino- and carboxyl-terminal sequences in Chp function. Surprisingly, we found that a GTPase-deficient mutant of Chp exhibited low transforming activity but that deletion of the amino terminus of Chp greatly enhanced its transforming activity. Thus, the amino terminus may serve as a negative regulator of Chp function. The carboxyl terminus of Cdc42 contains a CAAX (where C is cysteine, A is aliphatic amino acid, X is terminal amino acid) tetrapeptide sequence that signals for the posttranslational modification critical for Cdc42 membrane association and biological function. Although Chp lacks aCAAXmotif, we found that Chp showed carboxyl terminus-dependent localization to the plasma membrane and to endosomes. Furthermore, an intact carboxyl terminus was required for Chp transforming activity. However, treatment with inhibitors of protein palmitoylation, but not prenylation, caused Chp to mislocalize to the cytoplasm. Thus, Chp depends on palmitoylation, rather than isoprenylation, for membrane association and function. In summary, Chp is implicated in cell transformation, and the unique amino and carboxyl termini of Chp represent atypical mechanisms of regulation of Rho GTPase function.

  13. The role of SDF-1-CXCR4/CXCR7 axis in biological behaviors of adipose tissue-derived mesenchymal stem cells in vitro.

    Science.gov (United States)

    Li, Qiang; Zhang, Aijun; Tao, Changbo; Li, Xueyang; Jin, Peisheng

    2013-11-22

    Numerous studies have reported that CXCR4 and CXCR7 play an essential, but differential role in stromal cell-derived factor-1 (SDF-1)-inducing cell chemotaxis, viability and paracrine actions of BMSCs. Adipose tissue-derived mesenchymal stem cells (ADSCs) have been suggested to be potential seed cells for clinical application instead of bone marrow derived stroma cell (BMSCs). However, the function of SDF-1/CXCR4 and SDF-1/CXCR7 in ADSCs is not well understood. This study was designed to analyze the effect of SDF-1/CXCR4 and SDF-1/CXCR7 axis on ADSCs biological behaviors in vitro. Using Flow cytometry and Western blot methods, we found for the first time that CXCR4/CXCR7 expression was increased after treatment with SDF-1 in ADSCs. SDF-1 promoted ADSCs paracrine, proliferation and migration abilities. CXCR4 or CXCR7 antibody suppressed ADSCs paracrine action induced by SDF-1. The migration of ADSCs can be abolished by CXCR4 antibody, while the proliferation of ADSCs was only downregulated by CXCR7 antibody. Our study indicated that the angiogenesis of ADSCs is, at least partly, mediated by SDF-1/CXCR4 and SDF-1/CXCR7 axis. However, only binding of SDF-1/CXCR7 was required for proliferation of ADSCs, and CXCR7 was required for migration of ADSCs induced by SDF-1. Our studies provide evidence that the activation of either axis may be helpful to improve the effectiveness of ADSCs-based stem cell therapy.

  14. Modes-of-Action Related to Repeated Dose Toxicity: Tissue-Specific Biological Roles of PPARγ Ligand-Dependent Dysregulation in Nonalcoholic Fatty Liver Disease

    Directory of Open Access Journals (Sweden)

    Merilin Al Sharif

    2014-01-01

    Full Text Available Comprehensive understanding of the precise mode of action/adverse outcome pathway (MoA/AOP of chemicals becomes a key step towards superseding the current repeated dose toxicity testing methodology with new generation predictive toxicology tools. The description and characterization of the toxicological MoA leading to non-alcoholic fatty liver disease (NAFLD are of specific interest, due to its increasing incidence in the modern society. Growing evidence stresses on the PPARγ ligand-dependent dysregulation as a key molecular initiating event (MIE for this adverse effect. The aim of this work was to analyze and systematize the numerous scientific data about the steatogenic role of PPARγ. Over 300 papers were ranked according to preliminary defined criteria and used as reliable and significant sources of data about the PPARγ-dependent prosteatotic MoA. A detailed analysis was performed regarding proteins which PPARγ-mediated expression changes had been confirmed to be prosteatotic by most experimental evidence. Two probable toxicological MoAs from PPARγ ligand binding to NAFLD were described according to the Organisation for Economic Cooperation and Development (OECD concepts: (i PPARγ activation in hepatocytes and (ii PPARγ inhibition in adipocytes. The possible events at different levels of biological organization starting from the MIE to the organ response and the connections between them were described in details.

  15. The Emerging Role of the Phosphatidylinositol 3-Kinase/ Akt/Mammalian Target of Rapamycin Signaling Network in Cancer Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    James A. McCubrey

    2010-08-01

    Full Text Available The cancer stem cell theory entails the existence of a hierarchically organized, rare population of cells which are responsible for tumor initiation, self-renewal/maintenance, and mutation accumulation. The cancer stem cell proposition could explain the high frequency of cancer relapse and resistance to currently available therapies. The phosphatidylinositol 3-kinase (PI3K/Akt/mammalian target of rapamycin (mTOR signaling pathway regulates a wide array of physiological cell functions which include differentiation, proliferation, survival, metabolism, autophagy, and motility. Dysregulated PI3K/Akt/mTOR signaling has been documented in many types of neoplasias. It is now emerging that this signaling network plays a key role in cancer stem cell biology. Interestingly, cancer stem cells displayed preferential sensitivity to pathway inhibition when compared to healthy stem cells. This observation provides the proof-of-principle that functional differences in signaling pathways between neoplastic stem cells and healthy stem cells could be identified. In this review, we present the evidence which links the signals emanating from the PI3K/Akt/mTOR cascade with the functions of cancer stem cells, both in solid and hematological tumors. We then highlight how targeting PI3K/Akt/mTOR signaling with small molecules could improve cancer patient outcome.

  16. Using biological and physico-chemical test methods to assess the role of concrete mixture design in resistance to microbially induced corrosion

    Science.gov (United States)

    House, Mitchell Wayne

    to evaluate performance of concrete specimens under conditions designed to accelerate MIC. Concrete specimens representing 12 mixture designs were inoculated with 5 species of Thiobacillus bacteria and placed in a biological growth chamber designed to encourage bacterial growth and sulfuric acid production by optimizing temperature, delivering necessary nutrients, and providing hydrogen sulfide gas. Results indicate that using supplementary cementitious materials, limestone aggregates, and sulfate resistant cement can improve resistance to MIC. It is interesting to note that this study showed that unlike many other durability problems the role of water to cement ratio was unclear. The second method presented is a sulfuric acid immersion study designed to evaluate the resistance of 12 concrete mixture designs to 5 concentrations of sulfuric acid. Experimental protocols (like those in ASTM) previously considered trivial were found to have a dramatic effect on experimental results. It was found that using supplementary cementitious materials, limestone coarse aggregate, and sulfate resistant cement can increase concrete resistance to moderate sulfuric acid concentrations. The primary damage mechanism was observed to change depending on sulfuric acid concentration. Rapid deterioration of specimens exposed to aggressive sulfuric acid solutions indicates that degradation of concrete under the most severe MIC conditions (i.e., a pH concrete mixture proportions. A holistic approach is needed for these situations that considers environmental conditions as well.

  17. Plant synthetic biology.

    Science.gov (United States)

    Liu, Wusheng; Stewart, C Neal

    2015-05-01

    Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants.

  18. Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration.

    Science.gov (United States)

    Morrison, Margaux A; Silveira, Alexandra C; Huynh, Nancy; Jun, Gyungah; Smith, Silvia E; Zacharaki, Fani; Sato, Hajime; Loomis, Stephanie; Andreoli, Michael T; Adams, Scott M; Radeke, Monte J; Jelcick, Austin S; Yuan, Yang; Tsiloulis, Aristoteles N; Chatzoulis, Dimitrios Z; Silvestri, Giuliana; Kotoula, Maria G; Tsironi, Evangelia E; Hollis, Bruce W; Chen, Rui; Haider, Neena B; Miller, Joan W; Farrer, Lindsay A; Hageman, Gregory S; Kim, Ivana K; Schaumberg, Debra A; DeAngelis, Margaret M

    2011-10-01

    Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD) and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH) and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1), and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001). Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OH)D]) was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1) in this same family-based cohort. Initial findings were then

  19. Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Morrison Margaux A

    2011-10-01

    Full Text Available Abstract Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1, and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001. Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OHD] was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1 in this same family-based cohort. Initial

  20. Functions in Biological Kind Classification

    Science.gov (United States)

    Lombrozo, Tania; Rehder, Bob

    2012-01-01

    Biological traits that serve functions, such as a zebra's coloration (for camouflage) or a kangaroo's tail (for balance), seem to have a special role in conceptual representations for biological kinds. In five experiments, we investigate whether and why functional features are privileged in biological kind classification. Experiment 1…

  1. Functions in Biological Kind Classification

    Science.gov (United States)

    Lombrozo, Tania; Rehder, Bob

    2012-01-01

    Biological traits that serve functions, such as a zebra's coloration (for camouflage) or a kangaroo's tail (for balance), seem to have a special role in conceptual representations for biological kinds. In five experiments, we investigate whether and why functional features are privileged in biological kind classification. Experiment 1…

  2. Cellular Interactions and Biological Responses to Titanium Dioxide Nanoparticles in HepG2 and BEAS-2B Cells: Role of Cell Culture Media

    Science.gov (United States)

    ABSTRACT We have shown previously that the composition of the biological medium used in vitro can affect the cellular interaction and biological response of titanium dioxide nanoparticles (nano-TiO2) in human lung epithelial cells. However, it is unclear if these effects are co...

  3. Cellular Interactions and Biological Responses to Titanium Dioxide Nanoparticles in HepG2 and BEAS-2B Cells: Role of Cell Culture Media

    Science.gov (United States)

    ABSTRACT We have shown previously that the composition of the biological medium used in vitro can affect the cellular interaction and biological response of titanium dioxide nanoparticles (nano-TiO2) in human lung epithelial cells. However, it is unclear if these effects are co...

  4. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  5. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  6. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  7. Biologi Radiasi

    OpenAIRE

    Milla Yoesfianda

    2008-01-01

    Biologi radiasi adalah ilmu yang mempelajari tentang pengaruh dari ionisasi radiasi dalam tubuh makhluk hidup. Kemungkinan terjadinya efek biologis akibat interaksi radiasi dan jaringan tubuh manusia, berbanding lurus dengan besarnya dosis radiasi yang mengenai jaringan tubuh tersebut. Radiasi dapat mengakibatkan efek baik secara langsung maupun tidak langsung. Efek yang merusak secara biologis dari radiasi ionisasi diklasifikasikan menjadi tiga kategori utama, yaitu efek somatik determin...

  8. [Biological weapons].

    Science.gov (United States)

    Kerwat, K; Becker, S; Wulf, H; Densow, D

    2010-08-01

    Biological weapons are weapons of mass destruction that use pathogens (bacteria, viruses) or the toxins produced by them to target living organisms or to contaminate non-living substances. In the past, biological warfare has been repeatedly used. Anthrax, plague and smallpox are regarded as the most dangerous biological weapons by various institutions. Nowadays it seems quite unlikely that biological warfare will be employed in any military campaigns. However, the possibility remains that biological weapons may be used in acts of bioterrorism. In addition all diseases caused by biological weapons may also occur naturally or as a result of a laboratory accident. Risk assessment with regard to biological danger often proves to be difficult. In this context, an early identification of a potentially dangerous situation through experts is essential to limit the degree of damage. Georg Thieme Verlag KG Stuttgart * New York.

  9. Mathematical biology

    CERN Document Server

    Murray, James D

    1993-01-01

    The book is a textbook (with many exercises) giving an in-depth account of the practical use of mathematical modelling in the biomedical sciences. The mathematical level required is generally not high and the emphasis is on what is required to solve the real biological problem. The subject matter is drawn, e.g. from population biology, reaction kinetics, biological oscillators and switches, Belousov-Zhabotinskii reaction, reaction-diffusion theory, biological wave phenomena, central pattern generators, neural models, spread of epidemics, mechanochemical theory of biological pattern formation and importance in evolution. Most of the models are based on real biological problems and the predictions and explanations offered as a direct result of mathematical analysis of the models are important aspects of the book. The aim is to provide a thorough training in practical mathematical biology and to show how exciting and novel mathematical challenges arise from a genuine interdisciplinary involvement with the biosci...

  10. Frequency and prognostic role of mucosal healing in patients with Crohn’s disease and ulcerative colitis after one-year of biological therapy

    Science.gov (United States)

    Farkas, Klaudia; Lakatos, Péter László; Szűcs, Mónika; Pallagi-Kunstár, Éva; Bálint, Anita; Nagy, Ferenc; Szepes, Zoltán; Vass, Noémi; Kiss, Lajos S; Wittmann, Tibor; Molnár, Tamás

    2014-01-01

    AIM: To assess the endoscopic activity before and after a one-year period of biological therapy and to evaluate the frequency of relapses and need for retreatment after stopping the biologicals in patients with Crohn’s disease (CD) and ulcerative colitis (UC). METHODS: The data from 41 patients with CD and 22 patients with UC were assessed. Twenty-four CD patients received infliximab, and 17 received adalimumab. The endoscopic severity of CD was quantified with the simplified endoscopic activity score for Crohn’s disease in CD and with the Mayo endoscopic subscore in UC. RESULTS: Mucosal healing was achieved in 23 CD and 7 UC patients. Biological therapy had to be restarted in 78% of patients achieving complete mucosal healing with CD and in 100% of patients with UC. Neither clinical remission nor mucosal healing was associated with the time to restarting the biological therapy in either CD or UC. CONCLUSION: Mucosal healing did not predict sustained clinical remission in patients in whom the biological therapies had been stopped. PMID:24659890

  11. Weeds of Hawaii’s lands devoted to watershed protection and biodiversity conservation: Role of biological control as the missing piece in an integrated pest management strategy

    Science.gov (United States)

    Medeiros, Arthur C.; Loope, L.L.

    2011-01-01

    Despite Hawaii’s reputation as an extinction icon, significant biological resources remain, especially in watersheds, natural areas, and specialized edaphic sites (e.g., lava dry forest, coastal). While direct habitat destruction by humans continues, human-facilitated biological invaders are currently the primary agents of continuing degradation. The ability of invasive plants to have prolific seed production, efficient dispersal systems, and to become established in dense vegetation, complicated by Hawaii’s rugged topography, appears to render mechanical and chemical control as mere holding actions. Costly, ‘environmentally unfriendly’, and often ineffective, strategies using chemical and mechanical control on a large scale, despite the most valiant of efforts, can be viewed simply as attempts to buy time. Without increased levels of safely tested biological control, the seemingly inevitable result is the landscape level transformation of native forests, with potentially catastrophic consequences to cultural, biological, water, and economic resources. Increased levels of effective biological control for certain intractable invasive species appear to comprise a conspicuous ‘missing piece’ in our efforts to protect Hawaiian watersheds and other conservation lands.

  12. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  13. Elucidating the Biological Basis for the Reinforcing Actions of Alcohol in the Mesolimbic Dopamine System: The Role of Active Metabolites of Alcohol

    Directory of Open Access Journals (Sweden)

    Gerald A Deehan

    2013-08-01

    Full Text Available The development of successful pharmacotherapeutics for the treatment of alcoholism is predicated upon understanding the biological action of alcohol. A limitation of the alcohol research field has been examining the effects of alcohol only and ignoring the multiple biological active metabolites of alcohol. The concept that alcohol is a ‘pro-drug’ is not new. Alcohol is readily metabolized to acetaldehyde within the brain. Acetaldehyde is a highly reactive compound that forms a number of condensation products, including salsolinol and iso-salsolinol (acetaldehyde and dopamine. Recent experiments have established that numerous metabolites of ethanol do have direct CNS action, and could, in part or whole, mediate the reinforcing actions of alcohol within the mesolimbic dopamine system. The mesolimbic dopamine system originates in the ventral tegmental area (VTA and projects to forebrain regions that include the nucleus accumbens (Acb and the medial prefrontal cortex (mPFC and is thought to be the neurocircuitry governing the rewarding properties of drugs of abuse. Within this neurocircuitry there is convincing evidence that; 1 biologically active metabolites of alcohol can directly or indirectly increase the activity of VTA dopamine neurons, 2 alcohol and alcohol metabolites are reinforcing within the mesolimbic dopamine system, 3 inhibiting the alcohol metabolic pathway inhibits the biological consequences of alcohol exposure, 4 alcohol consumption can be reduced by inhibiting/attenuating the alcohol metabolic pathway in the mesolimbic dopamine system, 5 alcohol metabolites can alter neurochemical levels within the mesolimbic dopamine system, and 6 alcohol interacts with alcohol metabolites to enhance the actions of both compounds. The data indicate that there is a positive relationship between alcohol and alcohol metabolites in regulating the biological consequences of consuming alcohol and the potential of alcohol use escalating to

  14. Computational biology

    DEFF Research Database (Denmark)

    Hartmann, Lars Røeboe; Jones, Neil; Simonsen, Jakob Grue

    2011-01-01

    Computation via biological devices has been the subject of close scrutiny since von Neumann’s early work some 60 years ago. In spite of the many relevant works in this field, the notion of programming biological devices seems to be, at best, ill-defined. While many devices are claimed or proved t...

  15. Precision Measurement in Biology

    Science.gov (United States)

    Quake, Stephen

    Is biology a quantitative science like physics? I will discuss the role of precision measurement in both physics and biology, and argue that in fact both fields can be tied together by the use and consequences of precision measurement. The elementary quanta of biology are twofold: the macromolecule and the cell. Cells are the fundamental unit of life, and macromolecules are the fundamental elements of the cell. I will describe how precision measurements have been used to explore the basic properties of these quanta, and more generally how the quest for higher precision almost inevitably leads to the development of new technologies, which in turn catalyze further scientific discovery. In the 21st century, there are no remaining experimental barriers to biology becoming a truly quantitative and mathematical science.

  16. [Systems biology of cancer].

    Science.gov (United States)

    Barillot, Emmanuel; Calzone, Laurence; Zinovyev, Andrei

    2009-01-01

    Cancer Systems Biology is now accepted and recognized as a promising field both in biological and clinical research. It relies on a rigorous formalization of regulation networks into precise and unambiguous languages. It provides both detailed and modular views of the complex biological system of interest (which in cancer research is typically an interaction network governing essential cellular events such as proliferation, differentiation, cell death...) in order to facilitate the interpretation of molecular profiles of tumors. The translation of these networks into mathematical models allows prediction of the evolution of the system in time and under certain perturbations. As a result, it can not only propose specific target points for pharmaceutical purposes, but also anticipate the evolution of tumors as well as their classifications. These characteristics emphasize the important role of Systems Biology of Cancer in the future of biomedical research.

  17. Biological and Chemical Security

    Energy Technology Data Exchange (ETDEWEB)

    Fitch, P J

    2002-12-19

    The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism. The 1995 nerve gas attack in Tokyo's subway served to catalyze and focus the early LLNL program on civilian counter terrorism. In the same year, LLNL began CBNP using Laboratory-Directed R&D investments and a focus on biodetection. The Nunn-Lugar-Domenici Defense Against Weapons of Mass Destruction Act, passed in 1996, initiated a number of U.S. nonproliferation and counter-terrorism programs including the DOE (now NNSA) Chemical and Biological Nonproliferation Program (also known as CBNP). In 2002, the Department of Homeland Security was formed. The NNSA CBNP and many of the LLNL CBNP activities are being transferred as the new Department becomes operational. LLNL has a long history in national security including nonproliferation of weapons of mass destruction. In biology, LLNL had a key role in starting and implementing the Human Genome Project and, more recently, the Microbial Genome Program. LLNL has over 1,000 scientists and engineers with relevant expertise in biology, chemistry, decontamination, instrumentation, microtechnologies, atmospheric modeling, and field experimentation. Over 150 LLNL scientists and engineers work full time on chemical and biological national security projects.

  18. The Role and impact in the Development of Chinese Buddhism of Ancient Biology%中国佛教对古代生物学发展的作用和影响

    Institute of Scientific and Technical Information of China (English)

    刘学礼

    2011-01-01

    Because of its spirit of involvement in the world , chinese buddhism participated in some sci- ence and technology activities in ancient china, such as biology. In aspects of life form, species variation, plants and animals, human body and ecology, chinese buddhism has played a certain role and impact in the development of ancient biology.%中国佛教由于其积极入世的精神而主动参与了包括生物学在内的科技活动,在生命形态与物种变化、动植物、人体以及生态等方面,中国佛教对古代生物学发展起到了一定的作用和影响.

  19. Biological Oceanography

    Science.gov (United States)

    Dyhrman, Sonya

    2004-10-01

    The ocean is arguably the largest habitat on the planet, and it houses an astounding array of life, from microbes to whales. As a testament to this diversity and its importance, the discipline of biological oceanography spans studies of all levels of biological organization, from that of single genes, to organisms, to their population dynamics. Biological oceanography also includes studies on how organisms interact with, and contribute to, essential global processes. Students of biological oceanography are often as comfortable looking at satellite images as they are electron micrographs. This diversity of perspective begins the textbook Biological Oceanography, with cover graphics including a Coastal Zone Color Scanner image representing chlorophyll concentration, an electron micrograph of a dinoflagellate, and a photograph of a copepod. These images instantly capture the reader's attention and illustrate some of the different scales on which budding oceanographers are required to think. Having taught a core graduate course in biological oceanography for many years, Charlie Miller has used his lecture notes as the genesis for this book. The text covers the subject of biological oceanography in a manner that is targeted to introductory graduate students, but it would also be appropriate for advanced undergraduates.

  20. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  1. Pharmacokinetics of Exosomes-an Important Factor for Elucidating the Biological Roles of Exosomes and for the Development of Exosome-Based Therapeutics.

    Science.gov (United States)

    Morishita, Masaki; Takahashi, Yuki; Nishikawa, Makiya; Takakura, Yoshinobu

    2017-03-07

    Exosomes are small membrane vesicles containing lipids, proteins, and nucleic acids. Recently, researchers have uncovered that exosomes are involved in various biological events, such as tumor growth, metastasis, and the immune response, by delivering their cargos to exosome-receiving cells. Moreover, exosomes are expected to be employed in therapeutic treatments, such as tissue regeneration therapy and antitumor immunotherapy, since exosomes are effective delivery vehicles for proteins, nucleic acids, and other bioactive compounds. To elucidate the biological functions of exosomes, and for the development of exosome-based therapeutics, the pharmacokinetics of exosomes is important. In this review, we aim to summarize current knowledge about the pharmacokinetics and biodistribution of exosomes. The pharmacokinetics of exogenously administered exosomes is discussed based on the tissue distribution, types of cells taking up exosomes, and key molecules in the pharmacokinetics of exosomes. In addition, recent progress in the methods to control the pharmacokinetics of exosomes is reviewed.

  2. 初中生物课堂教学中学生角色意识的培养初探%Exploration on Developing Students' Awareness of Role in Middle School Biology Classroom Teaching

    Institute of Scientific and Technical Information of China (English)

    张兵

    2011-01-01

    生物这门学科在初中阶段课时相对较少,学生不够重视,这些都给教学增加了难度。怎么样才能在有限的课时内,有效地完成教学任务?如何提高生物课堂教学效率值得思考。本文就如何建立积极的师生情感,大胆地运用生物课本剧、单元知识竞赛等教学手段,激发学生的学习兴趣,提高学生学习的积极性和主动性,帮助学生逐步确立在生物课堂教学中的主体地位的角色意识,充分发挥学生的主体作用,进而提高课堂教学效率,阐述了自己的一点做法与心得。%Biological discipline in the middle school class is relatively small, the students not paying enough attention, which gave the teaching more diffcult. How can in the limited class and effectively complete the task of teaching? How to improve the eff- cienoy of biological classroom teaching is worth considering. In this paper, how to build a positive teachers and students, bold use of biological textbook, unit quizzes and other teaching methods to stimulate student interest in learning, improve student learning enthusiasm and initiative to help students gradually established in the biology classroom teaching the subject status of the role of consciousness, and givv full play the main role of students, thereby increasing the efficiency of classroom teaching, laying out his practice and exuerieuce.

  3. The role of North Atlantic Ocean circulation and biological sequestration on atmospheric CO2 uptake during the last deglaciation (CL Division Outstanding ECS Award Lecture)

    Science.gov (United States)

    Muschitiello, Francesco; D'Andrea, William J.; Dokken, Trond M.; Schmittner, Andreas

    2017-04-01

    Understanding the impact of ocean circulation on the global atmospheric CO2 budget is of paramount importance for anticipating the consequences of projected future changes in Atlantic Meridional Overturning Circulation (AMOC). In particular, the efficiency of the oceanic biological pump can impact atmospheric CO2 through changes in vertical carbon export mediated by variations in the nutrient inventory of the North Atlantic basin. However, the causal relationship between North Atlantic Ocean circulation, biological carbon sequestration, and atmospheric CO2 is poorly understood. Here we present new high-resolution planktic-benthic 14C data and biomarker records from an exceptionally well-dated marine core from the Nordic Seas spanning the last deglaciation ( 15,000-10,000 years BP). The records document for the first time large and rapid atmospheric CO2 drawdowns and increase in plankton stocks during major North Atlantic cooling events. Using transient climate simulations from a fully coupled climate-biosphere model, we show that minor perturbations of the North Atlantic biological pump resulting from surface freshening and AMOC weakening can have a major impact on the global atmospheric CO2 budget. Furthermore, our data help clarifying the timing and magnitude of the deglacial CO2 signal recorded in Antarctic ice cores. We conclude that the global CO2 budget is more sensitive to perturbations in North Atlantic circulation than previously thought, which has significance in the future debate of the AMOC response to anthropogenic warming.

  4. Grand challenges for biological engineering.

    Science.gov (United States)

    Yoon, Jeong-Yeol; Riley, Mark R

    2009-09-22

    Biological engineering will play a significant role in solving many of the world's problems in medicine, agriculture, and the environment. Recently the U.S. National Academy of Engineering (NAE) released a document "Grand Challenges in Engineering," covering broad realms of human concern from sustainability, health, vulnerability and the joy of living. Biological engineers, having tools and techniques at the interface between living and non-living entities, will play a prominent role in forging a better future. The 2010 Institute of Biological Engineering (IBE) conference in Cambridge, MA, USA will address, in part, the roles of biological engineering in solving the challenges presented by the NAE. This letter presents a brief outline of how biological engineers are working to solve these large scale and integrated problems of our society.

  5. Grand challenges for biological engineering

    Directory of Open Access Journals (Sweden)

    Riley Mark R

    2009-09-01

    Full Text Available Abstract Biological engineering will play a significant role in solving many of the world's problems in medicine, agriculture, and the environment. Recently the U.S. National Academy of Engineering (NAE released a document "Grand Challenges in Engineering," covering broad realms of human concern from sustainability, health, vulnerability and the joy of living. Biological engineers, having tools and techniques at the interface between living and non-living entities, will play a prominent role in forging a better future. The 2010 Institute of Biological Engineering (IBE conference in Cambridge, MA, USA will address, in part, the roles of biological engineering in solving the challenges presented by the NAE. This letter presents a brief outline of how biological engineers are working to solve these large scale and integrated problems of our society.

  6. Foldit Biology

    Science.gov (United States)

    2015-07-31

    Report 8/1/2013-7/31/2015 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Foldit Biology NOOO 14-13-C-0221 Sb. GRANT NUMBER N/A Sc. PROGRAM ELEMENT...Include area code) Unclassified Unclassified Unclassified (206) 616-2660 Zoran Popović Foldit Biology (Task 1, 2, 3, 4) Final Report...Period Covered by the Report August 1, 2013 – July 31, 2015 Date of Report: July 31, 2015 Project Title: Foldit Biology Contract Number: N00014-13

  7. Biology teachers

    African Journals Online (AJOL)

    Mathematics, Science and Biology teachers code switch when they teach. ... (by constantly translating back and forth), and argue for a 'separation approach' ..... for the classroom, only 3 students did not give an answer to this open-ended.

  8. Biology and Water Pollution Control.

    Science.gov (United States)

    Warren, Charles E.

    Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past,…

  9. Biology and Water Pollution Control.

    Science.gov (United States)

    Warren, Charles E.

    Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past,…

  10. Determination of clozapine in hair and nail: the role of keratinous biological materials in the identification of a bloated cadaver case.

    Science.gov (United States)

    Chen, Hang; Xiang, Ping; Shen, Min

    2014-02-01

    Keratinous biological materials, such as hair and nails, offer a substantially longer retrospective window of detection compared to other body fluids. Little research on drug analysis in nails is currently being conducted. In this study, the hair and nails from a bloated cadaver was analyzed. The study showed that the forensic toxicology results of keratinous biological materials could provide valuable clues for solving cases. In this study, a method was developed for the extraction and analysis of clozapine from hair and nails. The keratinous bio-samples were washed and then pulverized using a freeze mill. After ultrasonic bath extraction, the supernatants were analyzed by ultra-performance liquid chromatography tandem mass spectrometer (UPLC-MS/MS). The method presented in this study proved to be reliable, specific, selective and sensitive with high precision and accuracy. Clozapine was found in both hair and nails from a long term user's remains, even after serious decomposition. The mean concentration of clozapine in the hair was 322.9 pg/mg and 138.3 pg/mg in the nails. Toxicological results helped police narrow the scope of the investigation and improved the efficiency of the breaking of the case. The findings of the present study demonstrated that the method can be used in forensic investigation. Toxicological results increased the efficiency of cadaver identification and the solving of the case. The study demonstrated that hair and nail analysis could provide vital clues for solving cases and showed the value of keratinous biological materials in the forensics field.

  11. Estimation of the role of global biological filters in the geochemical migration of trace elements in the ocean: The marginal filter of the ocean

    Science.gov (United States)

    Demina, L. L.

    2011-07-01

    A quantitative estimate has been made for the contribution of biological processes to accumulation and transformation of the trace elements in the marginal biofilter of the ocean. It has been demonstrated that the proportion of phytoplankton having the largest biomass reaches 96-99% of the total mass of trace elements accumulated by biota. The mass of trace elements taken up by bivalved mollusks is tens to hundreds of times less than this, while that by macrophytes is an order of magnitude less than the latter. A dynamic parameter of the biogenic migration, namely the duration of the biological cycle of phytoplankton, has been calculated; this value does not exceed 2-3 days for Zn, Ni, Cu, Cd, Pb, Co, Fe, and Mn. First the trace metal balance in the whole body of mussels Mytilus spp. between the soft tissues and shells was calculated based on their weight proportion (0.1 and 0.9, correspondingly). As a result it was revealed that carbonate shells serve a great reservoir of Mn, Fe, Co, Ni, Cu and As and biomineralization is an important process in their bioaccumulation. The suggested new approach can be applied when making environmental and geochemical estimates of biotic self-purification of water bodies and when using shells as mineral supplements.

  12. On the Role of Visual Teaching in Biology Teaching%直观教学在生物教学中的作用

    Institute of Scientific and Technical Information of China (English)

    戎鹏柱

    2012-01-01

    直观教学是生物教学中最重要的教学手段之一,几乎所有的生物课都能利用这种方法教学,利用这一手段的效果能直接决定学生的学习效果。所以,教师必须对直观教学的意义、种类和运用方法有全面深入的了解,并掌握相关技能和技巧,才能不断提高教学质量。%Visual teaching is one of the most important teaching methods in biology teaching,for it can be used in nearly all biology classes to directly improve students' learning effect.Therefore,the teacher must deeply understand visual teaching method,and grasp relevant skills,so as to continuously improve teaching quality.

  13. The role of psychosocial and biological variables in separating chronic and non-chronic major depression and early-late-onset dysthymia.

    Science.gov (United States)

    Szádóczky, E; Fazekas, I; Rihmer, Z; Arató, M

    1994-09-01

    Psychosocial (sociodemographic characteristics, loss and separation and family atmosphere in childhood, recent life events) and biological (family history, DST, TRH-test) variables were investigated in 180 patients with Major Depression (MD) and Dysthymic Disorder (DD). The aim of the study was to reveal certain differences between the chronic and non-chronic course of MD and the early- and late-onset subtypes of dysthymia. When comparing the two course patterns of MD, a higher rate of malignant tumours among first-degree relatives, a greater number of long-lasting stress situations before the index depressive episode, longer duration of the previous episodes, less frequent DST nonsuppression, and a blunted TSH response to TRH were found in patients with a chronic course of MD. Several factors seem to influence the course pattern of MD, or else the chronic form represents a subgroup within MD. The late-onset dysthymics were mainly women with a low level of education, a lower suicidal tendency, normal suppression in DST, and a lack of blunted TSH responses to TRH administration during the period of double depression. The early-onset dysthymics showed a higher number of persons who had never married, who presented a more traumatic and frustrating childhood background, and who had a higher rate of DST non-suppressors and blunted TSH responses after TRH administration during the period of their double depression. Our data suggest that late-onset dysthymia might be a biologically distinct subgroup of chronic depression.

  14. The role of EPR spectroscopy in studies of the oxidative status of biological systems and the antioxidative properties of various compounds - REVIEW

    Directory of Open Access Journals (Sweden)

    IVAN SPASOJEVIĆ

    2011-05-01

    Full Text Available In this era of intense study of free radicals and antioxidants, electron paramagnetic resonance (EPR is arguably the best-suited technique for such research, particularly when considering biochemical and biological systems. No attempt was made to cover all the topics of EPR application but instead attention was restricted to two areas that are both novel and received less attention in previous reviews. In the first section, the application of EPR in assessing the oxidative status of various biological systems, using endogenous stabile paramagnetic species, such as the ascorbyl radical, semiquinone, melanin, and oxidized pigments, is addressed. The second section covers the use of EPR in the emerging field of antioxidant development, using EPR spin-trapping and spin-probing techniques. In both sections, in addition to giving an overview of the available literature, examples (mostly from the authors’ recent work are also presented in sufficient detail to illustrate how to explore the full potential of EPR. This review aims at encouraging biologists, chemists and pharmacologists interested in the redox metabolism of living systems, free radical chemistry or antioxidative properties of new drugs and natural products to take advantage of this technique for their investigations.

  15. Managing biological diversity

    Science.gov (United States)

    Samson, Fred B.; Knopf, Fritz L.

    1993-01-01

    Biological diversity is the variety of life and accompanying ecological processes (Off. Technol. Assess. 1987, Wilcove and Samson 1987, Keystone 1991). Conservation of biological diversity is a major environmental issue (Wilson 1988, Counc. Environ. Quality 1991). The health and future of the earth's ecological systems (Lubchenco et al. 1991), global climate change (Botkin 1990), and an ever-increasing rate in loss of species, communities, and ecological systems (Myers 1990) are among issues drawing biological diversity to the mainstream of conservation worldwide (Int. Union Conserv. Nat. and Nat. Resour. [IUCN] et al. 1991). The legal mandate for conserving biological diversity is now in place (Carlson 1988, Doremus 1991). More than 19 federal laws govern the use of biological resources in the United States (Rein 1991). The proposed National Biological Diversity Conservation and Environmental Research Act (H.R. 585 and S.58) notes the need for a national biological diversity policy, would create a national center for biological diversity research, and recommends a federal interagency strategy for ecosystem conservation. There are, however, hard choices ahead for the conservation of biological diversity, and biologists are grappling with how to set priorities in research and management (Roberts 1988). We sense disillusion among field biologists and managers relative to how to operationally approach the seemingly overwhelming charge of conserving biological diversity. Biologists also need to respond to critics like Hunt (1991) who suggest a tree farm has more biological diversity than an equal area of old-growth forest. At present, science has played only a minor role in the conservation of biological diversity (Weston 1992) with no unified approach available to evaluate strategies and programs that address the quality and quantity of biological diversity (Murphy 1990, Erwin 1992). Although actions to conserve biological diversity need to be clearly defined by

  16. An occupational hygiene investigation of exposure to acrylamide and the role for urinary S-carboxyethyl-cysteine (CEC) as a biological marker.

    Science.gov (United States)

    Bull, Peter J; Brooke, Richard K; Cocker, John; Jones, Katharine; Warren, Nicholas

    2005-11-01

    Acrylamide has a range of toxicological hazards including neurotoxicity and reproductive toxicity; however, occupational risk management is driven by its genotoxic and carcinogenic potential (it is classified within the EU as a Category 2 carcinogen, R45 and Category 2 mutagen, R46). Since there is the potential for skin absorption and systemic toxicity, biological monitoring may be a useful aid for the assessment of exposure via inhalation, ingestion and dermal absorption. However, there are currently no biological monitoring guidance values (BMGVs). This study describes an extensive survey of potential workplace exposure to acrylamide at the Ciba (Bradford) site to gather data suitable for a BMGV. This manufacturing site is typical within the industry as a whole and includes a cross section of activities and tasks representative of acrylamide exposure. Acrylamide is used in the manufacture of polyacrylamide based products for applications in water treatment; oil and mineral extraction; paper, paint and textile processes. Workers (62 plus 6 controls) with varying potential exposures provided a total of 275 pre shift and 247 post-shift urine samples along with 260 personal air samples. A small non-exposed control group was similarly monitored. Urine samples were analysed for S-carboxyethyl-cysteine (CEC). Airborne, surface and glove samples were analysed for acrylamide. Inhalation exposures were well controlled with values consistently below one-tenth of the UK Workplace Exposure Limit. Engineering controls, personal protective equipment and work practice, all contributed to good control of occupational exposure. CEC was found in urine samples from both exposed workers and non-occupationally exposed controls. At the low levels of exposure found, smoking made a significant contribution to urinary CEC levels. Nevertheless a correlation between urinary CEC and airborne acrylamide was found. A mixed effects model incorporating inhalation concentrations of acrylamide

  17. Biological preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  18. Biological Oceanography

    Science.gov (United States)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  19. Does constructive neutral evolution play an important role in the origin of cellular complexity? Making sense of the origins and uses of biological complexity.

    Science.gov (United States)

    Speijer, Dave

    2011-05-01

    Recently, constructive neutral evolution has been touted as an important concept for the understanding of the emergence of cellular complexity. It has been invoked to help explain the development and retention of, amongst others, RNA splicing, RNA editing and ribosomal and mitochondrial respiratory chain complexity. The theory originated as a welcome explanation of isolated small scale cellular idiosyncrasies and as a reaction to 'overselectionism'. Here I contend, that in its extended form, it has major conceptual problems, can not explain observed patterns of complex processes, is too easily dismissive of alternative selectionist models, underestimates the creative force of complexity as such, and--if seen as a major evolutionary mechanism for all organisms--could stifle further thought regarding the evolution of highly complex biological processes. Copyright © 2011 WILEY Periodicals, Inc.

  20. In vivo models of brain tumors: roles of genetically engineered mouse models in understanding tumor biology and use in preclinical studies.

    Science.gov (United States)

    Simeonova, Iva; Huillard, Emmanuelle

    2014-10-01

    Although our knowledge of the biology of brain tumors has increased tremendously over the past decade, progress in treatment of these deadly diseases remains modest. Developing in vivo models that faithfully mirror human diseases is essential for the validation of new therapeutic approaches. Genetically engineered mouse models (GEMMs) provide elaborate temporally and genetically controlled systems to investigate the cellular origins of brain tumors and gene function in tumorigenesis. Furthermore, they can prove to be valuable tools for testing targeted therapies. In this review, we discuss GEMMs of brain tumors, focusing on gliomas and medulloblastomas. We describe how they provide critical insights into the molecular and cellular events involved in the initiation and maintenance of brain tumors, and illustrate their use in preclinical drug testing.

  1. New insights into the structure, assembly and biological roles of 10-12 nm connective tissue microfibrils from fibrillin-1 studies.

    Science.gov (United States)

    Jensen, Sacha A; Handford, Penny A

    2016-04-01

    The 10-12 nm diameter microfibrils of the extracellular matrix (ECM) impart both structural and regulatory properties to load-bearing connective tissues. The main protein component is the calcium-dependent glycoprotein fibrillin, which assembles into microfibrils at the cell surface in a highly regulated process involving specific proteolysis, multimerization and glycosaminoglycan interactions. In higher metazoans, microfibrils act as a framework for elastin deposition and modification, resulting in the formation of elastic fibres, but they can also occur in elastin-free tissues where they perform structural roles. Fibrillin microfibrils are further engaged in a number of cell matrix interactions such as with integrins, bone morphogenetic proteins (BMPs) and the large latent complex of transforming growth factor-β (TGFβ). Fibrillin-1 (FBN1) mutations are associated with a range of heritable connective disorders, including Marfan syndrome (MFS) and the acromelic dysplasias, suggesting that the roles of 10-12 nm diameter microfibrils are pleiotropic. In recent years the use of molecular, cellular and whole-organism studies has revealed that the microfibril is not just a structural component of the ECM, but through its network of cell and matrix interactions it can exert profound regulatory effects on cell function. In this review we assess what is known about the molecular properties of fibrillin that enable it to assemble into the 10-12 nm diameter microfibril and perform such diverse roles.

  2. (Biological dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  3. Scaffolded biology.

    Science.gov (United States)

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  4. Biology Notes.

    Science.gov (United States)

    School Science Review, 1984

    1984-01-01

    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  5. Biology Notes.

    Science.gov (United States)

    School Science Review, 1981

    1981-01-01

    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  6. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  7. What do we really know about the signalling role of plumage colour in blue tits? A case study of impediments to progress in evolutionary biology.

    Science.gov (United States)

    Parker, Timothy H

    2013-08-01

    Evolutionary biologists seek to explain the origin and maintenance of phenotypes, and a substantial portion of this research is accomplished by thorough study of individual species. For instance, many researchers study individual species to understand evolution of ornamental traits which appear to be products of sexual selection. I explored our understanding of sexual ornaments in a well-studied vertebrate species that may serve as a case study for research programs in evolutionary biology. I attempted to located all published papers examining plumage colour and variables related to sexual selection hypotheses in a common European songbird, the blue tit (Cyanistes caeruleus). Researchers have estimated over 1200 statistical relationships with plumage colour of blue tits in 52 studies. However, of the approximately 1000 main-effect relationships from the 48 studies that are candidates for inclusion in this meta-analysis, more than 400 were reported without details of strength and direction. Circumstantial evidence suggests that an unknown number of other estimated effects remain unpublished. Missing information is a substantial barrier to interpretation of these papers and to meta-analytic synthesis. Examination and analysis of funnel plots indicated that unpublished effects may be a biased sample of all effects, especially for comparisons of plumage colour to age and individual quality, and possibly also to measures of mate choice. Further, type I error was likely elevated by the large number of statistical comparisons evaluated, the frequent use of iterative model-building procedures, and a willingness to interpret a wide variety of results as support for a hypothesis. Type I errors were made more problematic because blue tit plumage researchers only rarely have attempted to replicate important findings in their own work or that of others. Replication is essential to drawing robust scientific conclusions, especially in probabilistic systems with moderate to weak

  8. Bridging the gap between systems biology and synthetic biology.

    Science.gov (United States)

    Liu, Di; Hoynes-O'Connor, Allison; Zhang, Fuzhong

    2013-01-01

    Systems biology is an inter-disciplinary science that studies the complex interactions and the collective behavior of a cell or an organism. Synthetic biology, as a technological subject, combines biological science and engineering, allowing the design and manipulation of a system for certain applications. Both systems and synthetic biology have played important roles in the recent development of microbial platforms for energy, materials, and environmental applications. More importantly, systems biology provides the knowledge necessary for the development of synthetic biology tools, which in turn facilitates the manipulation and understanding of complex biological systems. Thus, the combination of systems and synthetic biology has huge potential for studying and engineering microbes, especially to perform advanced tasks, such as producing biofuels. Although there have been very few studies in integrating systems and synthetic biology, existing examples have demonstrated great power in extending microbiological capabilities. This review focuses on recent efforts in microbiological genomics, transcriptomics, proteomics, and metabolomics, aiming to fill the gap between systems and synthetic biology.

  9. Elucidation of the role of biological factors and device design in cerebral NIRS using an in vivo hematoma model based on high-intensity focused ultrasound

    Science.gov (United States)

    Wang, Jianting; Huang, Stanley; Myers, Matthew; Chen, Yu; Welle, Cristin; Pfefer, Joshua

    2016-03-01

    Near-Infrared Spectroscopy (NIRS) is an emerging medical countermeasure for rapid, field detection of hematomas caused by traumatic brain injury (TBI). Bench and animal tests to determine NIRS sensitivity and specificity are needed. However, current animal models involving non-invasively induced, localized neural damage are limited. We investigated an in vivo murine hematoma model in which cerebral hemorrhage was induced noninvasively by high-intensity focused ultrasound (HIFU) with calibrated positioning and parameters. To characterize the morphology of induced hematomas, we used skull-intact histological evaluation. A multi-wavelength fiber-optic NIRS system with three source-detector separation distances was used to detect hematoma A 1.1 MHz transducer produced consistent small-to-medium hematoma localized to a single hemisphere, along with bruising of the scalp, with a low mortality rate. A 220 kHz transducer produced larger, more diffuse hematomas, with higher variability in size and a correspondingly higher mortality rate. No skin bruising or blood accumulation between the skin and skull was observed following injury application with the 220 kHz transducer. Histological analysis showed higher sensitivity for larger hematomas (>4x4 mm2). NIRS optical density change after HIFU was able to detect all hematomas, with sensitivity dependent on wavelength and separation distance. While improvements in methods for validating cerebral blood distribution are needed, the HIFU hematoma model provided useful insights that will inform development of biologically relevant, performance test methods for cerebral NIRS systems.

  10. The role of topography in the transformation of spatiotemporal patterns by a large-scale, biologically realistic model of the rat dentate gyrus.

    Science.gov (United States)

    Yu, Gene J; Hendrickson, Phillip J; Robinson, Brian S; Song, Dong; Berger, Theodore W

    2013-01-01

    A large-scale, biologically realistic, computational model of the rat hippocampus is being constructed to study the input-output transformation that the hippocampus performs. In the initial implementation, the layer II entorhinal cortex neurons, which provide the major input to the hippocampus, and the granule cells of the dentate gyrus, which receive the majority of the input, are modeled. In a previous work, the topography, or the wiring diagram, connecting these two populations had been derived and implemented. This paper explores the consequences of two features of the topography, the distribution of the axons and the size of the neurons' axon terminal fields. The topography converts streams of independently generated random Poisson trains into structured spatiotemporal patterns through spatiotemporal convergence achievable by overlapping axon terminal fields. Increasing the axon terminal field lengths allowed input to converge over larger regions of space resulting in granule activation across a greater area but did not increase the total activity as a function of time as the number of targets per input remained constant. Additional simulations demonstrated that the total distribution of spikes in space depends not on the distribution of the presynaptic axons but the distribution of the postsynaptic population. Analyzing spike counts emphasizes the importance of the postsynaptic distribution, but it ignores the fact that each individual input may be carrying unique information. Therefore, a metric should be created that relates and tracks individual inputs as they are propagated and integrated through hippocampus.

  11. The potential role of 'Candidatus Microthrix parvicella' in phosphorus removal during sludge bulking in two full-scale enhanced biological phosphorus removal plants.

    Science.gov (United States)

    Wang, Juan; Qi, Rong; Liu, Miaomiao; Li, Qian; Bao, Haipeng; Li, Yaming; Wang, Shen; Tandoi, Valter; Yang, Min

    2014-01-01

    We investigated the bacterial community compositions and phosphorus removal performance under sludge bulking and non-bulking conditions in two biological wastewater treatment systems (conventional A²/O (anaerobic/anoxic/aerobic) and inverted A²/O (anoxic/anaerobic/aerobic) processes) receiving the same raw wastewater. Sludge bulking resulted in significant shift in bacterial compositions from Proteobacteria dominance to Actinobacteria dominance, characterized by the significant presence of filamentous 'Candidatus Microthrix parvicella'. Quantitative real-time polymerase chain reaction (PCR) analysis revealed that the relative abundance of 'Candidatus Accumulibacter phosphatis', a key polyphosphate-accumulating organism responsible for phosphorus removal, with respect to 16s rRNA genes of total bacteria was 0.8 and 0.7%, respectively, for the conventional and inverted A²/O systems when sludge bulking occurred, which increased to 8.2 and 12.3% during the non-bulking period. However, the total phosphorus removal performance during the bulking period (2-week average: 97 ± 1 and 96 ± 1%, respectively) was not adversely affected comparable to that during the non-bulking period (2-week average: 96 ± 1 and 96 ± 1%, respectively). Neisser staining revealed the presence of large polyphosphate granules in 'Candidatus Microthrix parvicella', suggesting that this microbial group might have been responsible for phosphorus removal during the sludge bulking period when 'Candidatus Accumulibacter phosphatis' was excluded from the systems.

  12. The importance of CELF control: molecular and biological roles of the CUG-BP, Elav-like family of RNA-binding proteins.

    Science.gov (United States)

    Dasgupta, Twishasri; Ladd, Andrea N

    2012-01-01

    RNA processing is important for generating protein diversity and modulating levels of protein expression. The CUG-BP, Elav-like family (CELF) of RNA-binding proteins regulate several steps of RNA processing in the nucleus and cytoplasm, including pre-mRNA alternative splicing, C to U RNA editing, deadenylation, mRNA decay, and translation. In vivo, CELF proteins have been shown to play roles in gametogenesis and early embryonic development, heart and skeletal muscle function, and neurosynaptic transmission. Dysregulation of CELF-mediated programs has been implicated in the pathogenesis of human diseases affecting the heart, skeletal muscles, and nervous system.

  13. 护创膜在兔微粒皮移植术中的作用研究%Role of biological protective dressing in microskin grafting in rabbit

    Institute of Scientific and Technical Information of China (English)

    张卫东; 谢卫国; 赵超莉; 王辉; 刘淑华; 叶子青

    2012-01-01

    Objective To study the effect of biological protective dressing made from porcine peritoneum in covering wounds with microskin grafts.Methods Twenty New Zealand rabbits were divided into ten couples according to the random number table.Rabbits in each couple underwent surgery at the same time.A piece of full-thickness skin of 5 cm in diameter was removed symmetrically from the left and right sides of the back of each rabbit,thus forming two wounds with full-thickness skin defect.One fifth of one piece of skin of one rabbit was cut into tiny pieces of 0.2-0.5 mm in size (microskin).Then the microskin pieces were spread on the two wounds of the donor rabbit with the microskin/wound area ratio 1∶ 10.The two wounds of each rabbit covered with microskin were divided into two groups according to the random number table.One wound was covered with biological protective dressing prepared with porcine peritoneum as experiment group,and the other was covered with the rest allograft in full size obtained from the other rabbit of each couple as control group.The general condition of wound was observed at post operation week (POW) 1-4.Wound healing rate was calculated at POW 3 and 4.Wound healing time was recorded.Specimens were harvested from wounds for histological observation at POW 1-4.Data were processed with paired t test.Results (1) At POW 1,the biological protective dressings were found to attach firmly to the wounds in experiment group without obvious inflammatory response; the allografts survived well on the wounds in control group.At POW 2,the coverings attached well to the wounds of both groups,but became drier and darker as compared with those at POW 1.At POW 3,some wounds of the two groups healed when the coverings desiccated and separated.At POW 4,all the wounds of both groups healed without obvious difference in appearance.(2) The wound healing rates of the experiment and contrl groups were respectively (92.8 ± 6.2) %and (91.3±7.3)% (t =0.54,P >0

  14. A review of the biologic and pharmacologic role of docosapentaenoic acid n-3 [v2; ref status: indexed, http://f1000r.es/41a

    Directory of Open Access Journals (Sweden)

    Puya G Yazdi

    2014-08-01

    Full Text Available Fish oil contains a complex mixture of omega-3 fatty acids, of which eicosapentaenoic acid (EPA, docosapentaenoic acid (DPA, and docosahexaenoic acid (DHA are the three predominant forms. There has been a plethora of previous research on the effects and associations of fish oil supplementation with various clinical manifestations. While the majority of this work was focused on EPA and DHA as the active compounds, emerging research has begun to elucidate the specific role that DPA plays in these physiological processes and its differences with the other omega-3 fatty acids. The purpose of this review is to focus on the new studies undertaken with DPA. This review summarizes the biochemical mechanisms involved in the biosynthesis and metabolism of DPA before focusing on its effects in cardiovascular disease, immune function, and psychiatric and cognitive health. The limited studies point toward a positive role that DPA supplementation can play in these processes and that is separate and distinct from traditional supplementation with DHA and EPA.

  15. Biological Mechanisms Underlying the Ultraviolet Radiation-Induced Formation of Skin Wrinkling and Sagging II: Over-Expression of Neprilysin Plays an Essential Role

    Directory of Open Access Journals (Sweden)

    Genji Imokawa

    2015-04-01

    Full Text Available Our previous studies strongly indicated that the up-regulated activity of skin fibroblast-derived elastase plays a pivotal role in wrinkling and/or sagging of the skin via the impairment of elastic fiber configuration and the subsequent loss of skin elasticity. Fortunately, we succeeded in identifying human skin fibroblast-derived elastase as a previously known enzyme, neprilysin or neutral endopeptidase (NEP. We have also characterized epithelial-mesenchymal paracrine cytokine interactions between UVB-exposed-keratinocytes and dermal fibroblasts and found that interleukin-1α and granulocyte macrophage colony stimulatory factor (GM-CSF are intrinsic cytokines secreted by UVB-exposed keratinocytes that stimulate the expression of neprilysin by fibroblasts. On the other hand, direct UVA exposure of human fibroblasts significantly stimulates the secretion of IL-6 and also elicits a significant increase in the gene expression of matrix metallo-protease(MMP-1 as well as neprilysin (to a lesser extent, which is followed by distinct increases in their protein and enzymatic activity levels. Direct UVA exposure of human keratinocytes also stimulates the secretion of IL-6, IL-8 and GM-CSF but not of IL-1 and endothelin-1. These findings suggest that GM-CSF secreted by UVA-exposed keratinocytes as well as IL-6 secreted by UVA-exposed dermal fibroblasts play important and additional roles in UVA-induced sagging and wrinkling by up-regulation of neprilysin and MMP-1, respectively, in dermal fibroblasts.

  16. Biological mechanisms underlying the ultraviolet radiation-induced formation of skin wrinkling and sagging II: over-expression of neprilysin plays an essential role.

    Science.gov (United States)

    Imokawa, Genji; Nakajima, Hiroaki; Ishida, Koichi

    2015-04-08

    Our previous studies strongly indicated that the up-regulated activity of skin fibroblast-derived elastase plays a pivotal role in wrinkling and/or sagging of the skin via the impairment of elastic fiber configuration and the subsequent loss of skin elasticity. Fortunately, we succeeded in identifying human skin fibroblast-derived elastase as a previously known enzyme, neprilysin or neutral endopeptidase (NEP). We have also characterized epithelial-mesenchymal paracrine cytokine interactions between UVB-exposed-keratinocytes and dermal fibroblasts and found that interleukin-1α and granulocyte macrophage colony stimulatory factor (GM-CSF) are intrinsic cytokines secreted by UVB-exposed keratinocytes that stimulate the expression of neprilysin by fibroblasts. On the other hand, direct UVA exposure of human fibroblasts significantly stimulates the secretion of IL-6 and also elicits a significant increase in the gene expression of matrix metallo-protease(MMP)-1 as well as neprilysin (to a lesser extent), which is followed by distinct increases in their protein and enzymatic activity levels. Direct UVA exposure of human keratinocytes also stimulates the secretion of IL-6, IL-8 and GM-CSF but not of IL-1 and endothelin-1. These findings suggest that GM-CSF secreted by UVA-exposed keratinocytes as well as IL-6 secreted by UVA-exposed dermal fibroblasts play important and additional roles in UVA-induced sagging and wrinkling by up-regulation of neprilysin and MMP-1, respectively, in dermal fibroblasts.

  17. Mesoscopic biology

    Indian Academy of Sciences (India)

    G V Shivashankar

    2002-02-01

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological systems. In recent years advances in technology have led to the study of some of the design principles of these machines; in particular at the level of an individual molecule. For example, the forces that operate in molecular interactions, the stochasticity involved in these interactions and their spatio-temporal dynamics are beginning to be explored. Understanding such design principles is opening new possibilities in mesoscopic physics with potential applications.

  18. On the role of the cis Hoogsteen:sugar-edge family of base pairs in platforms and triplets-quantum chemical insights into RNA structural biology.

    Science.gov (United States)

    Sharma, Purshotam; Sponer, Judit E; Sponer, Jirí; Sharma, Sitansh; Bhattacharyya, Dhananjay; Mitra, Abhijit

    2010-03-11

    Base pairs belonging to the cis Hoogsteen:sugar-edge (H:S) family play important structural roles in folded RNA molecules. Several of these are present in internal loops, where they are involved in interactions leading to planar dinucleotide platforms which stabilize higher order structures such as base triplets and quartets. We report results of analysis of 30 representative examples spanning 16 possible base pair combinations, with several of them showing multimodality of base pairing geometry. The geometries of 23 of these base pairs were modeled directly from coordinates extracted from RNA crystal structures. The other seven were predicted structures which were modeled on the basis of observed isosteric analogues. After appropriate satisfaction of residual valencies, these structures were relaxed using the B3LYP/6-31G(d,p) method and interaction energies were derived at the RIMP2/aug-cc-pVDZ level of theory. The geometries for each of the studied base pairs have been characterized in terms of the number and nature of H-bonds, rmsd values observed on optimization, base pair geometrical parameters, and sugar pucker analysis. In addition to its evaluation, the nature of intermolecular interaction in these complexes was also analyzed using Morokuma decomposition. The gas phase interaction energies range between -5.2 and -20.6 kcal/mol and, in contrast to the H:S trans base pairs, show enhanced relative importance of the electron correlation component, indicative of the greater role of dispersion energy in stabilization of these base pairs. The rich variety of hydrogen bonding pattern, involving the flexible sugar edge, appears to hold the key to several features of structural motifs, such as planarity and propensity to participate in triplets, observed in this family of base pairs. This work explores these aspects by integrating database analysis, and detailed base pairing geometry analysis at the atomistic level, with ab initio computation of interaction energies

  19. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  20. Essential and distinct roles for cdc42 and rac1 in the regulation of Schwann cell biology during peripheral nervous system development

    DEFF Research Database (Denmark)

    Benninger, Yves; Thurnherr, Tina; Pereira, Jorge A

    2007-01-01

    During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue-specific......During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue......-specific conditional gene targeting to show that members of the Rho GTPases, cdc42 and rac1, have different and essential roles in axon sorting by Schwann cells. Our results indicate that although cdc42 is required for normal Schwann cell proliferation, rac1 regulates Schwann cell process extension and stabilization...

  1. [Cathepsin L cysteine protease from Taenia solium: its biological role in the infection and potential use for the immunodiagnosis of neurocysticercosis].

    Science.gov (United States)

    León, Nancy; Padilla, Carlos; Pajuelo, Mónica; Sheen, Patricia; Zimic, Mirko

    2013-07-01

    Taenia solium is a plane helminth responsible for taeniasis and human cysticercosis, the latter being the result of the consumption of infective eggs. Cysticerci can develop in different human tissues, often in the central nervous system, causing neurocysticercosis (NCC). For the diagnosis of NCC, an adequate interpretation of clinical data, neuroimaging results and serological tests are required. However, serological tests could be improved by developing candidate antigens able to increase their sensibility and specificity. In the last years, a series of surface and secretory proteins of T. solium essential for the parasite-host interaction have been described. One of these families is cathepsin L cysteine proteases, which have a predominant role in the development and survival of the parasite. They take part in the tissue invasion, immune response evasion, excystation and encystment of cysticercus. They are considered potential antigens for the immunodiagnosis of neurocysticercosis.

  2. Inter-dependent mechanisms behind cognitive dysfunction, vascular biology and Alzheimer’s dementia in Down syndrome: multi-faceted roles of APP

    Directory of Open Access Journals (Sweden)

    Dean eNizetic

    2015-12-01

    Full Text Available People with Down syndrome (DS virtually all develop intellectual disability (ID of varying degree of severity, and also have a high risk of early Alzheimer’s disease (AD. Intellectual disability prior to the onset of dementia, and its relationship to the onset of dementia in DS is a complex phenomenon influenced by many factors, and scarcely understood. Unravelling the causative factors and modulators of these processes remains a challenge, with potential to be informative for both ID and AD, for the development of early biomarkers and/or therapeutic approaches. We review the potential relative and inter-connected roles of the chromosome 21 gene for amyloid precursor protein (APP, in both pathological conditions. Rare non-DS people with duplication of APP (dupAPP get familial early onset AD (FEOAD with virtually 100% penetrance and prominent cerebrovascular pathology, but don’t suffer from ID before dementia onset. All of these features appear to be radically different in DS. On the other hand, rare individuals with partial trisomy 21 (T21 (with APP, but not DS-critical region in trisomy have been described having ID. Likewise, partial T21 DS (without APP trisomy show a range of ID, but no AD pathology. We review the multi-faceted roles of APP that might affect cognitive functioning. Given the fact that both Aβ secretion and synaptic maturation/plasticity are dependent on neuronal activity, we explore how this conflicting inter-dependency might affect cognitive pathogenesis in a dynamic way in DS, throughout the lifespan of an individual.

  3. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area ​Other Fact Sheets What is structural biology? Structural biology is the study of how biological ...

  4. A comparative nitrogen balance and productivity analysis of legume and non-legume supported cropping systems: the potential role of biological nitrogen fixation

    Directory of Open Access Journals (Sweden)

    Pietro P M Iannetta

    2016-11-01

    Full Text Available The potential of biological nitrogen fixation (BNF to provide sufficient N for production have encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertiliser, although few studies have systematically evaluated the effect of optimising the balance between legumes and non N-fixing crops to optimise production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new, legume–based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g. grains, forages and intercrops across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32-115 kg ha-1 annually. Output in terms of total biomass (grain, forage, etc. was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years. BNF was lower when the legume fraction increased to 0.6-0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertiliser was normally applied. Forage (e.g. grass and clover, as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes have the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output.

  5. A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation

    Science.gov (United States)

    Iannetta, Pietro P. M.; Young, Mark; Bachinger, Johann; Bergkvist, Göran; Doltra, Jordi; Lopez-Bellido, Rafael J.; Monti, Michele; Pappa, Valentini A.; Reckling, Moritz; Topp, Cairistiona F. E.; Walker, Robin L.; Rees, Robert M.; Watson, Christine A.; James, Euan K.; Squire, Geoffrey R.; Begg, Graham S.

    2016-01-01

    The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume–based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g., grains, forages and intercrops) across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32 to 115 kg ha−1 annually. Output in terms of total biomass (grain, forage, etc.) was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years). BNF was lower when the legume fraction increased to 0.6–0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertilizer was normally applied. Forage (e.g., grass and clover), as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes has the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output. PMID:27917178

  6. Dominating biological networks.

    Directory of Open Access Journals (Sweden)

    Tijana Milenković

    Full Text Available Proteins are essential macromolecules of life that carry out most cellular processes. Since proteins aggregate to perform function, and since protein-protein interaction (PPI networks model these aggregations, one would expect to uncover new biology from PPI network topology. Hence, using PPI networks to predict protein function and role of protein pathways in disease has received attention. A debate remains open about whether network properties of "biologically central (BC" genes (i.e., their protein products, such as those involved in aging, cancer, infectious diseases, or signaling and drug-targeted pathways, exhibit some topological centrality compared to the rest of the proteins in the human PPI network.To help resolve this debate, we design new network-based approaches and apply them to get new insight into biological function and disease. We hypothesize that BC genes have a topologically central (TC role in the human PPI network. We propose two different concepts of topological centrality. We design a new centrality measure to capture complex wirings of proteins in the network that identifies as TC those proteins that reside in dense extended network neighborhoods. Also, we use the notion of domination and find dominating sets (DSs in the PPI network, i.e., sets of proteins such that every protein is either in the DS or is a neighbor of the DS. Clearly, a DS has a TC role, as it enables efficient communication between different network parts. We find statistically significant enrichment in BC genes of TC nodes and outperform the existing methods indicating that genes involved in key biological processes occupy topologically complex and dense regions of the network and correspond to its "spine" that connects all other network parts and can thus pass cellular signals efficiently throughout the network. To our knowledge, this is the first study that explores domination in the context of PPI networks.

  7. Biological Correlates of Empathy

    Directory of Open Access Journals (Sweden)

    E. Timucin Oral

    2010-04-01

    Full Text Available Empathy can be defined as the capacity to know emotionally what another is experiencing from within the frame of reference of that other person and the capacity to sample the feelings of another or it can be metaphorized as to put oneself in another’s shoes. Although the concept of empathy was firstly described in psychological theories, researches studying the biological correlates of psychological theories have been increasing recently. Not suprisingly, dinamically oriented psychotherapists Freud, Kohut, Basch and Fenichel had suggested theories about the biological correlates of empathy concept and established the basis of this modality decades ago. Some other theorists emphasized the importance of empathy in the early years of lifetime regarding mother-child attachment in terms of developmental psychology and investigated its role in explanation of psychopathology. The data coming from some of the recent brain imaging and animal model studies also seem to support these theories. Although increased activity in different brain regions was shown in many of the brain imaging studies, the role of cingulate cortex for understanding mother-child relationship was constantly emphasized in nearly all of the studies. In addition to these studies, a group of Italian scientists has defined a group of neurons as “mirror neurons” in their studies observing rhesus macaque monkeys. Later, they also defined mirror neurons in human studies, and suggested them as “empathy neurons”. After the discovery of mirror neurons, the hopes of finding the missing part of the puzzle for understanding the biological correlates of empathy raised again. Although the roles of different biological parameters such as skin conductance and pupil diameter for defining empathy have not been certain yet, they are going to give us the opportunity to revise the inconsistent basis of structural validity in psychiatry and to stabilize descriptive validity. In this review, the

  8. The unfolded protein response and its potential role in Huntington's disease elucidated by a systems biology approach [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Ravi Kiran Reddy Kalathur

    2016-03-01

    Full Text Available Huntington ́s disease (HD is a progressive, neurodegenerative disease with a fatal outcome. Although the disease-causing gene (huntingtin has been known for over 20 years, the exact mechanisms leading to neuronal cell death are still controversial. One potential mechanism contributing to the massive loss of neurons observed in the brain of HD patients could be the unfolded protein response (UPR activated by accumulation of misfolded proteins in the endoplasmic reticulum (ER. As an adaptive response to counter-balance accumulation of un- or misfolded proteins, the UPR upregulates transcription of chaperones, temporarily attenuates new translation, and activates protein degradation via the proteasome. However, persistent ER stress and an activated UPR can also cause apoptotic cell death. Although different studies have indicated a role for the UPR in HD, the evidence remains inconclusive. Here, we present extensive bioinformatic analyses that revealed UPR activation in different experimental HD models based on transcriptomic data. Accordingly, we have identified 53 genes, including RAB5A, HMGB1, CTNNB1, DNM1, TUBB, TSG101, EEF2, DYNC1H1, SLC12A5, ATG5, AKT1, CASP7 and SYVN1 that provide a potential link between UPR and HD. To further elucidate the potential role of UPR as a disease-relevant process, we examined its connection to apoptosis based on molecular interaction data, and identified a set of 40 genes including ADD1, HSP90B1, IKBKB, IKBKG, RPS3A and LMNB1, which seem to be at the crossroads between these two important cellular processes. Remarkably, we also found strong correlation of UPR gene expression with the length of the polyglutamine tract of Huntingtin, which is a critical determinant of age of disease onset in human HD patients pointing to the UPR as a promising target for therapeutic intervention. The study is complemented by a newly developed web-portal called UPR-HD (http://uprhd.sysbiolab.eu that enables visualization and

  9. The Predictive Impact of Biological and Sociocultural Factors on Executive Processing: The Role of Age, Education, and Frequency of Reading and Writing Habits.

    Science.gov (United States)

    Cotrena, Charles; Branco, Laura D; Cardoso, Caroline O; Wong, Cristina Elizabeth I; Fonseca, Rochele P

    2016-01-01

    Although the impact of education and age on executive functions (EF) has been widely studied, the influence of daily cognitive stimulation on EF has not been sufficiently investigated. Therefore, the aim of the present study was to evaluate whether the age, education, and frequency of reading and writing habits (FRWH) of healthy adults could predict their performance on measures of inhibition and cognitive flexibility. Inhibition speed, inhibitory control, and set shifting were assessed using speed, accuracy, and discrepancy scores on the Trail-Making Test (TMT) and Hayling Test. Demographic characteristics and the FRWH were assessed using specialized questionnaires. Regression analyses showed that age and the FRWH predicted speed and accuracy on the TMT. The FRWH predicted both speed and accuracy on the Hayling Test, for which speed and accuracy scores were also partly explained by age and education, respectively. Surprisingly, only the FRWH was associated with Hayling Test discrepancy scores, considered one of the purest EF measures. This highlights the importance of regular cognitive stimulation over the number of years of formal education on EF tasks. Further studies are required to investigate the role of the FRWH so as to better comprehend its relationship with EF and general cognition.

  10. Emerging role of cancer stem cells in the biology and treatment of ovarian cancer: basic knowledge and therapeutic possibilities for an innovative approach.

    Science.gov (United States)

    Tomao, Federica; Papa, Anselmo; Rossi, Luigi; Strudel, Martina; Vici, Patrizia; Lo Russo, Giuseppe; Tomao, Silverio

    2013-08-01

    In 2013 there will be an estimated 22,240 new diagnoses and 14,030 deaths from ovarian cancer in the United States. Despite the improved surgical approach and the novel active drugs that are available today in clinical practice, about 80% of women presenting with late-stage disease have a 5-year survival rate of only 30%. In the last years a growing scientific knowledge about the molecular pathways involved in ovarian carcinogenesis has led to the discovery and evaluation of several novel molecular targeted agents, with the aim to test alternative models of treatment in order to overcome the clinical problem of resistance. Cancer stem cells tend to be more resistant to chemotherapeutic agents and radiation than more differentiated cellular subtypes from the same tissue. In this context the study of ovarian cancer stem cells is taking on an increasingly important strategic role, mostly for the potential therapeutic application in the next future. In our review, we focused our attention on the molecular characteristics of epithelial ovarian cancer stem cells, in particular on possible targets to hit with targeted therapies.

  11. Biological Databases

    Directory of Open Access Journals (Sweden)

    Kaviena Baskaran

    2013-12-01

    Full Text Available Biology has entered a new era in distributing information based on database and this collection of database become primary in publishing information. This data publishing is done through Internet Gopher where information resources easy and affordable offered by powerful research tools. The more important thing now is the development of high quality and professionally operated electronic data publishing sites. To enhance the service and appropriate editorial and policies for electronic data publishing has been established and editors of article shoulder the responsibility.

  12. The ontology of biological sequences

    Directory of Open Access Journals (Sweden)

    Kelso Janet

    2009-11-01

    Full Text Available Abstract Background Biological sequences play a major role in molecular and computational biology. They are studied as information-bearing entities that make up DNA, RNA or proteins. The Sequence Ontology, which is part of the OBO Foundry, contains descriptions and definitions of sequences and their properties. Yet the most basic question about sequences remains unanswered: what kind of entity is a biological sequence? An answer to this question benefits formal ontologies that use the notion of biological sequences and analyses in computational biology alike. Results We provide both an ontological analysis of biological sequences and a formal representation that can be used in knowledge-based applications and other ontologies. We distinguish three distinct kinds of entities that can be referred to as "biological sequence": chains of molecules, syntactic representations such as those in biological databases, and the abstract information-bearing entities. For use in knowledge-based applications and inclusion in biomedical ontologies, we implemented the developed axiom system for use in automated theorem proving. Conclusion Axioms are necessary to achieve the main goal of ontologies: to formally specify the meaning of terms used within a domain. The axiom system for the ontology of biological sequences is the first elaborate axiom system for an OBO Foundry ontology and can serve as starting point for the development of more formal ontologies and ultimately of knowledge-based applications.

  13. Di-Peptide-Modified Gemini Surfactants as Gene Delivery Vectors: Exploring the Role of the Alkyl Tail in Their Physicochemical Behavior and Biological Activity.

    Science.gov (United States)

    Al-Dulaymi, Mays A; Chitanda, Jackson M; Mohammed-Saeid, Waleed; Araghi, Hessamaddin Younesi; Verrall, Ronald E; Grochulski, Pawel; Badea, Ildiko

    2016-09-01

    The aim of this work was to elucidate the structure-activity relationship of new peptide-modified gemini surfactant-based carriers. Glycyl-lysine modified gemini surfactants that differ in the length and degree of unsaturation of their alkyl tail were used to engineer DNA nano-assemblies. To probe the optimal nitrogen to phosphate (N/P) ratio in the presence of helper lipid, in vitro gene expression and cell toxicity measurements were carried out. Characterization of the nano-assemblies was accomplished by measuring the particle size and surface charge. Morphological characteristics and lipid organization were studied by small angle X-ray scattering technique. Lipid monolayers were studied using a Langmuir-Blodgett trough. The highest activity of glycyl-lysine modified gemini surfactants was observed with the 16-carbon tail compound at 2.5 N/P ratio, showing a 5- to 10-fold increase in the level of reporter protein compared to the 12 and 18:1 carbon tail compounds. This ratio is significantly lower compared to the previously studied gemini surfactants with alkyl or amino- spacers. In addition, the 16-carbon tail compound exhibited the highest cell viability (85%). This high efficiency is attributed to the lowest critical micelle concentration of the 16-tail gemini surfactant and a balanced packing of the nanoparticles by mixing a saturated and unsaturated lipid together. At the optimal N/P ratio, all nanoparticles exhibited an inverted hexagonal lipid assembly. The results show that the length and nature of the tail of the gemini surfactants play an important role in determining the transgene efficiency of the delivery system. We demonstrated here that the interplay between the headgroup and the nature of tail is specific to each series, thus in the process of rational design, the contribution of the latter should be assessed in the appropriate context.

  14. Isolation and properties of 600-kDa and 23-kDa haemolymph proteins from the tsetse fly, Glossina morsitans: their possible role as biological insecticides.

    Science.gov (United States)

    Ochanda, J O; Osir, E O; Nguu, E K; Olembo, N K

    1992-01-01

    The haemolymph of the tsetse fly, Glossina morsitans morsitans, contains a high (lipophorin) and a low molecular weight protein of high densities, 1.11 and 1.29 g/ml, respectively. The purification of the proteins was achieved by a combination of density gradient ultracentrifugation and reported gel permeation chromatography. The lipophorin is of high molecular weight (M(r) integral of 600,000) and consists of two apoproteins, apolipophorin I (M(r) integral of 250,000) and apolipophorin II (M(r) integral of 80,000) both of which are glycosylated. Lipophorin also has a pI of 6.1. However, electrophoresis under non-denaturing and denaturing conditions showed the low molecular weight protein to be a single polypeptide chain (M(r) integral of 23,000). Amino acid analysis revealed a relatively high content of the acidic amino acids as well as serine and glycine. The protein contained lipids as shown by Sudan Black staining but was unglycosylated. Using rabbit antiserum against the isolated protein in immunodiffusion and immunoblotting experiments, no cross-reactivity was detected with haemolymph samples from insects representing six orders. In conclusion, the finding of lipophorin suggests that, although flies primarily utilize proline for their energy needs, there is an active transport mechanism for the supply of lipid requirements. However, the results for the low molecular weight protein indicate that the protein is unique to Glossina, suggesting that it may have an important role in the physiology of this insect and is therefore a significant target for vector management.

  15. Island biology and morphological divergence of the Skyros wall lizard Podarcis gaigeae: a combined role for local selection and genetic drift on color morph frequency divergence?

    Directory of Open Access Journals (Sweden)

    Runemark Anna

    2010-09-01

    Full Text Available Abstract Background Patterns of spatial variation in discrete phenotypic traits can be used to draw inferences about the adaptive significance of traits and evolutionary processes, especially when compared to patterns of neutral genetic variation. Population divergence in adaptive traits such as color morphs can be influenced by both local ecology and stochastic factors such as genetic drift or founder events. Here, we use quantitative color measurements of males and females of Skyros wall lizard, Podarcis gaigeae, to demonstrate that this species is polymorphic with respect to throat color, and the morphs form discrete phenotypic clusters with limited overlap between categories. We use divergence in throat color morph frequencies and compare that to neutral genetic variation to infer the evolutionary processes acting on islet- and mainland populations. Results Geographically close islet- and mainland populations of the Skyros wall lizard exhibit strong divergence in throat color morph frequencies. Population variation in throat color morph frequencies between islets was higher than that between mainland populations, and the effective population sizes on the islets were small (Ne:s ST for throat color morph frequencies fell within the neutral FST-distribution estimated from microsatellite markers, and genetic drift could thus not be rejected as an explanation for the pattern. Moreover, for both comparisons among mainland-mainland population pairs and between mainland-islet population pairs, morph frequency divergence was significantly correlated with neutral divergence, further pointing to some role for genetic drift in divergence also at the phenotypic level of throat color morphs. Conclusions Genetic drift could not be rejected as an explanation for the pattern of population divergence in morph frequencies. In spite of an expected stabilising selection, throat color frequencies diverged in the islet populations. These results suggest that

  16. Biologically inspired intelligent robots

    Science.gov (United States)

    Bar-Cohen, Yoseph; Breazeal, Cynthia

    2003-07-01

    Humans throughout history have always sought to mimic the appearance, mobility, functionality, intelligent operation, and thinking process of biological creatures. This field of biologically inspired technology, having the moniker biomimetics, has evolved from making static copies of human and animals in the form of statues to the emergence of robots that operate with realistic behavior. Imagine a person walking towards you where suddenly you notice something weird about him--he is not real but rather he is a robot. Your reaction would probably be "I can't believe it but this robot looks very real" just as you would react to an artificial flower that is a good imitation. You may even proceed and touch the robot to check if your assessment is correct but, as oppose to the flower case, the robot may be programmed to respond physical and verbally. This science fiction scenario could become a reality as the current trend continues in developing biologically inspired technologies. Technology evolution led to such fields as artificial muscles, artificial intelligence, and artificial vision as well as biomimetic capabilities in materials science, mechanics, electronics, computing science, information technology and many others. This paper will review the state of the art and challenges to biologically-inspired technologies and the role that EAP is expected to play as the technology evolves.

  17. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  18. The aesthetics of chemical biology.

    Science.gov (United States)

    Parsons, Glenn

    2012-12-01

    Scientists and philosophers have long reflected on the place of aesthetics in science. In this essay, I review these discussions, identifying work of relevance to chemistry and, in particular, to the field of chemical biology. Topics discussed include the role of aesthetics in scientific theory choice, the aesthetics of molecular images, the beauty-making features of molecules, and the relation between the aesthetics of chemical biology and the aesthetics of industrial design.

  19. Biology-Inspired Autonomous Control

    Science.gov (United States)

    2011-08-31

    Mimicry of biological systems, in the form of precise mathematical or physical dynamical modeling, is yielding impressive insight into the underlying...also seem to exhibit large individual variations in response. It has long been known that honeybees change behavioral roles within a colony as they age ...vertebrates, honeybees show individual behavioral differences even within the same age class. Again, discussion with insect biology experimentalists

  20. Biological scaling and physics

    Indian Academy of Sciences (India)

    A R