WorldWideScience

Sample records for biological cell investigations

  1. Laboratory investigations in cell biology. Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Bregman, A.A.

    1987-01-01

    This text contains 18 lab projects that explore the structural, biochemical, and physiological nature of eukaryotic cells. Topics are largely traditional, however, several investigations employ new methodologies. Offers extended coverage of biochemistry. Materials have been selected for availability and ease of handling: e.g. Project 4 - extraction of DNA and RNA done with calf liver, Project 9 - succinate dehydrogenase activity studied in mitochondria isolated from cauliflower. There is more procedural detail than found in most lab manuals, negating the need for constant instructional details. And a variety of methodologies is introduced, such as Cytochemistry, Spectrophotometry, Electrophoresis, Cell Fractionation, silver staining of active sites of RNA transcription, and many more. Pages are perforated for collecting and grading.

  2. 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.

  3. Malignant mesothelioma, clinical, diagnostic and cell biological investigations

    NARCIS (Netherlands)

    M.A. Versnel (Marjan)

    1989-01-01

    textabstractThe purpose of this study was to improve the diagnosis of human malignant mesothelioma on the one hand and to investigate the growth regulation and transformation of normal and malignant mesothelial cells on the other hand. In this thesis improvement of diagnosis was approached by the se

  4. Cellular Analysis of Adult Neural Stem Cells for Investigating Prion Biology.

    Science.gov (United States)

    Haigh, Cathryn L

    2017-01-01

    Traditional primary and secondary cell cultures have been used for the investigation of prion biology and disease for many years. While both types of cultures produce highly valid and immensely valuable results, they also have their limitations; traditional cell lines are often derived from cancers, therefore subject to numerous DNA changes, and primary cultures are labor-intensive and expensive to produce requiring sacrifice of many animals. Neural stem cell (NSC) cultures are a relatively new technology to be used for the study of prion biology and disease. While NSCs are subject to their own limitations-they are generally cultured ex vivo in environments that artificially force their growth-they also have their own unique advantages. NSCs retain the ability for self-renewal and can therefore be propagated in culture similarly to secondary cultures without genetic manipulation. In addition, NSCs are multipotent; they can be induced to differentiate into mature cells of central nervous system (CNS) linage. The combination of self-renewal and multipotency allows NSCs to be used as a primary cell line over multiple generations saving time, costs, and animal harvests, thus providing a valuable addition to the existing cell culture repertoire used for investigation of prion biology and disease. Furthermore, NSC cultures can be generated from mice of any genotype, either by embryonic harvest or harvest from adult brain, allowing gene expression to be studied without further genetic manipulation. This chapter describes a standard method of culturing adult NSCs and assays for monitoring NSC growth, migration, and differentiation and revisits basic reactive oxygen species detection in the context of NSC cultures.

  5. Historical perspectives in fat cell biology: the fat cell as a model for the investigation of hormonal and metabolic pathways.

    Science.gov (United States)

    Lafontan, Max

    2012-01-15

    For many years, there was little interest in the biochemistry or physiology of adipose tissue. It is now well recognized that adipocytes play an important dynamic role in metabolic regulation. They are able to sense metabolic states via their ability to perceive a large number of nervous and hormonal signals. They are also able to produce hormones, called adipokines, that affect nutrient intake, metabolism and energy expenditure. The report by Rodbell in 1964 that intact fat cells can be obtained by collagenase digestion of adipose tissue revolutionized studies on the hormonal regulation and metabolism of the fat cell. In the context of the advent of systems biology in the field of cell biology, the present seems an appropriate time to look back at the global contribution of the fat cell to cell biology knowledge. This review focuses on the very early approaches that used the fat cell as a tool to discover and understand various cellular mechanisms. Attention essentially focuses on the early investigations revealing the major contribution of mature fat cells and also fat cells originating from adipose cell lines to the discovery of major events related to hormone action (hormone receptors and transduction pathways involved in hormonal signaling) and mechanisms involved in metabolite processing (hexose uptake and uptake, storage, and efflux of fatty acids). Dormant preadipocytes exist in the stroma-vascular fraction of the adipose tissue of rodents and humans; cell culture systems have proven to be valuable models for the study of the processes involved in the formation of new fat cells. Finally, more recent insights into adipocyte secretion, a completely new role with major metabolic impact, are also briefly summarized.

  6. Assessment of biology investigations.

    OpenAIRE

    Roberts, R.; Gott, R.

    2003-01-01

    This review makes a case for the assessment of investigations against the Concepts of Evidence in written tests as a potentially more reliable and valid way of assessing the ideas used in all types of biology investigations, thus reducing the distorting effect of assessment on the curriculum.

  7. Preface of the "Symposium on Mathematical Models and Methods to investigate Heterogeneity in Cell and Cell Population Biology"

    Science.gov (United States)

    Clairambault, Jean

    2016-06-01

    This session investigates hot topics related to mathematical representations of cell and cell population dynamics in biology and medicine, in particular, but not only, with applications to cancer. Methods in mathematical modelling and analysis, and in statistical inference using single-cell and cell population data, should contribute to focus this session on heterogeneity in cell populations. Among other methods are proposed: a) Intracellular protein dynamics and gene regulatory networks using ordinary/partial/delay differential equations (ODEs, PDEs, DDEs); b) Representation of cell population dynamics using agent-based models (ABMs) and/or PDEs; c) Hybrid models and multiscale models to integrate single-cell dynamics into cell population behaviour; d) Structured cell population dynamics and asymptotic evolution w.r.t. relevant traits; e) Heterogeneity in cancer cell populations: origin, evolution, phylogeny and methods of reconstruction; f) Drug resistance as an evolutionary phenotype: predicting and overcoming it in therapeutics; g) Theoretical therapeutic optimisation of combined drug treatments in cancer cell populations and in populations of other organisms, such as bacteria.

  8. An open source based high content screening method for cell biology laboratories investigating cell spreading and adhesion.

    Directory of Open Access Journals (Sweden)

    Andre Schmandke

    Full Text Available BACKGROUND: Adhesion dependent mechanisms are increasingly recognized to be important for a wide range of biological processes, diseases and therapeutics. This has led to a rising demand of pharmaceutical modulators. However, most currently available adhesion assays are time consuming and/or lack sensitivity and reproducibility or depend on specialized and expensive equipment often only available at screening facilities. Thus, rapid and economical high-content screening approaches are urgently needed. RESULTS: We established a fully open source high-content screening method for identifying modulators of adhesion. We successfully used this method to detect small molecules that are able to influence cell adhesion and cell spreading of Swiss-3T3 fibroblasts in general and/or specifically counteract Nogo-A-Δ20-induced inhibition of adhesion and cell spreading. The tricyclic anti-depressant clomipramine hydrochloride was shown to not only inhibit Nogo-A-Δ20-induced cell spreading inhibition in 3T3 fibroblasts but also to promote growth and counteract neurite outgrowth inhibition in highly purified primary neurons isolated from rat cerebellum. CONCLUSIONS: We have developed and validated a high content screening approach that can be used in any ordinarily equipped cell biology laboratory employing exclusively freely available open-source software in order to find novel modulators of adhesion and cell spreading. The versatility and adjustability of the whole screening method will enable not only centers specialized in high-throughput screens but most importantly also labs not routinely employing screens in their daily work routine to investigate the effects of a wide range of different compounds or siRNAs on adhesion and adhesion-modulating molecules.

  9. Toward a systems biology approach to investigate cellular networks in normal and malignant B cells.

    Science.gov (United States)

    Basso, K

    2009-07-01

    In recent years, we experienced an increasing development of new technologies that aim to comprehensively dissect the molecular genetics of cellular phenotypes. Pioneering studies have been performed on leukemia and lymphoma and then extended to many other types of malignancies. Genome-wide technologies allow taking snapshots of defined cellular context from an unbiased angle highlighting a complexity that we still struggle to fully interpret. The increasing availability of technologies to detect genetic, transcriptional and post-transcriptional characteristics of cellular systems needs to be associated with the development of computational tools to fully investigate these data in an integrated way. The evolution of different genome-wide technologies as well as data mining and integration tools will be discussed following studies performed on normal and malignant human mature B cells.

  10. Importance of molecular cell biology investigations in human medicine in the story of the Hutchinson-Gilford progeria syndrome.

    Science.gov (United States)

    Raška, Ivan

    2010-09-01

    Ranged among laminopathies, Hutchinson-Gilford progeria syndrome is a syndrome that involves premature aging, leading usually to death at the age between 10 to 14 years predominatly due to a myocardial infarction or a stroke. In the lecture I shall overview the importance of molecular cell biology investigations that led to the discovery of the basic mechanism standing behind this rare syndrome. The genetic basis in most cases is a mutation at the nucleotide position 1824 of the lamin A gene. At this position, cytosine is substituted for thymine so that a cryptic splice site within the precursor mRNA for lamin A is generated. This results in a production of abnormal lamin A, termed progerin, its presence in cells having a deleterious dominant effect. Depending on the cell type and tissue, progerin induces a pleiotropy of defects that vary in different tissues. The present endeavour how to challenge this terrible disease will be also mentioned.

  11. [Cell biology and cosmetology].

    Science.gov (United States)

    Traniello, S; Cavalletti, T

    1991-01-01

    Cellular biology can become the natural support of research in the field of cosmetics because it is able to provide alternative experimental models which can partially replace the massive use of laboratory animals. Cultures of human skin cells could be used in tests investigating irritation of the skin. We have developed an "in vitro" experimental model that allows to evaluate the damage caused by the free radicals to the fibroblasts in culture and to test the protective action of the lipoaminoacids. Experimenting on human cell cultures presents the advantage of eliminating the extrapolation between the different species, of allowing a determination of the biological action of a substance and of evaluating its dose/response effect. This does not mean that "in vitro" experimenting could completely replace experimenting on living animals, but the "in vitro" model can be introduced in the realisation of preliminary screenings.

  12. Antithrombogenic investigation and biological behavior of cultured human umbilical vein endothelial cells on Ti-O film

    Institute of Scientific and Technical Information of China (English)

    CHEN; Junying; WAN; Guojiang; LENG; Yongxiang; YANG; Ping; SUN; Hong; WANG; Jin; HUANG; Nan; CHEN; Huaiqing; TANG; Rong

    2006-01-01

    Our previous research results have shown that the Ti-O films with appropriate characteristics possess great potentials for biomaterials application. In this paper, using plasma immersion ion implantation and deposition (PIII-D), titanium oxide thin films are fabricated onto silicon wafer. The antithrombogenesis of films is evaluated in vitro through the platelet adhesion investigation. The biological behavior of human umbilical vein endothelial cells (HUVEC) on the film surface is investigated in vitro by endothelial cell (EC) culture. Our results reveal that the crystalline Ti-O films exhibit attractive blood compatibility. The in vitro HUVEC-cultured investigation of Ti-O film surface has justified that the biological behavior of HUVECs on different structure surfaces is significantly different. The adherence, growth and proliferation of HUVECs to the crystalline Ti-O film surface are in order, by forming a perfect single layer, preserving the natural original shape and displaying the cobblestone road metal rank, and obviously superior to that on the amorphous Ti-O film surface. According to our study, the crystalline Ti-O film, with proper microstructure, is helpful for seeding Ecs and can be used as a functional surface for the adherence and growth of ECS.

  13. New method for investigation of cells and other biological objects in analytical cytology

    Science.gov (United States)

    Bilyi, Olexander I.; Getman, Vasyl B.; Kostyukevych, Sergey A.

    2001-05-01

    New method and instrument intended for checking the content of biology particles in dimension band 0.1-10.0 mkm in water flow is described in this report. The instrument measures the intensity of light scattered by the particles suspended in liquid flow when they are crossing the laser beam. The results of studying light scattered by platelet and bacterium's such a Pseudomonas aeruginosa, Escherichia coli, Micrococcus lutteus in such a liquid mediums as physiological solution and glucose solution are described.

  14. Cell biology perspectives in phage biology.

    Science.gov (United States)

    Ansaldi, Mireille

    2012-01-01

    Cellular biology has long been restricted to large cellular organisms. However, as the resolution of microscopic methods increased, it became possible to study smaller cells, in particular bacterial cells. Bacteriophage biology is one aspect of bacterial cell biology that has recently gained insight from cell biology. Despite their small size, bacteriophages could be successfully labeled and their cycle studied in the host cells. This review aims to put together, although non-extensively, several cell biology studies that recently pushed the elucidation of key mechanisms in phage biology, such as the lysis-lysogeny decision in temperate phages or genome replication and transcription, one step further.

  15. The Emergence of AFM Applications to Cell Biology: How new technologies are facilitating investigation of human cells in health and disease at the nanoscale.

    Science.gov (United States)

    Yang, Ruiguo; Xi, Ning; Fung, Carmen Kar Man; Seiffert-Sinha, Kristina; Lai, King Wai Chiu; Sinha, Animesh A

    2011-01-01

    Atomic Force Microscopy (AFM) based nanorobotics has been used for building nano devices in semiconductors for almost a decade. Leveraging the unparallel precision localization capabilities of this technology, high resolution imaging and mechanical property characterization is now increasingly being performed in biological settings. AFM also offers the prospect for handling and manipulating biological materials at nanometer scale. It has unique advantages over other methods, permitting experiments in the liquid phase where physiological conditions can be maintained. Taking advantage of these properties, our group has visualized membrane and cytoskeletal structures of live cells by controlling the interaction force of the AFM tip with cellular components at the nN or sub-nN range. Cell stiffness changes were observed by statistically analyzing the Young's modulus values of human keratinocytes before and after specific antibody treatment. Furthermore, we used the AFM cantilever as a robotic arm for mechanical pushing, pulling and cutting to perform nanoscale manipulations of cell-associated structures. AFM guided nano-dissection, or nanosurgery was enacted on the cell in order to sever intermediate filaments connecting neighboring keratinocytes via sub 100 nm resolution cuts. Finally, we have used a functionalized AFM tip to probe cell surface receptors to obtain binding force measurements. This technique formed the basis for Single Molecule Force Spectroscopy (SMFS). In addition to enhancing our basic understanding of dynamic signaling events in cell biology, these advancements in AFM based biomedical investigations can be expected to facilitate the search for biomarkers related to disease diagnosis progress and treatment.

  16. Laboratory of Cell and Molecular Biology

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory of Cell and Molecular Biology investigates the organization, compartmentalization, and biochemistry of eukaryotic cells and the pathology associated...

  17. Radiobiological investigations at tumor cell lines by exploiting chrono-biological aspects of chronological dose distributions

    CERN Document Server

    Ulmer, W

    2011-01-01

    Using 31P-NMR spectroscopy the chronological behavior of the ATP-metabolism of the tumor spheroids C3H-MA, 9L-Gliome and the mono-layer L1210 has been analyzed via decrease of the {\\beta}-peak. All three cell lines show characteristic periods, and a homeostatic control cannot be recognized. Essential components of these periods are circadian (i.e. one day), circa-semiseptan (i.e. 3.5 days) and circa-septan (i.e. one week). The determination of the survival fractions provides an optimum exploitation of radiation damages, when the ATP-concentration assumes a maximum value. This optimum is reached, when all three cycles exhibit the ATP maximum, which is only possible by accounting for the circa-septan rhythm. The goal of this study is to elaborate an optimal fractionation scheme with regard to the irradiation of tumors.

  18. Systems cell biology.

    Science.gov (United States)

    Mast, Fred D; Ratushny, Alexander V; Aitchison, John D

    2014-09-15

    Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology.

  19. Translational environmental biology: cell biology informing conservation.

    Science.gov (United States)

    Traylor-Knowles, Nikki; Palumbi, Stephen R

    2014-05-01

    Typically, findings from cell biology have been beneficial for preventing human disease. However, translational applications from cell biology can also be applied to conservation efforts, such as protecting coral reefs. Recent efforts to understand the cell biological mechanisms maintaining coral health such as innate immunity and acclimatization have prompted new developments in conservation. Similar to biomedicine, we urge that future efforts should focus on better frameworks for biomarker development to protect coral reefs.

  20. Recent progress in histochemistry and cell biology.

    Science.gov (United States)

    Hübner, Stefan; Efthymiadis, Athina

    2012-04-01

    Studies published in Histochemistry and Cell Biology in the year 2011 represent once more a manifest of established and newly sophisticated techniques being exploited to put tissue- and cell type-specific molecules into a functional context. The review is therefore the Histochemistry and Cell Biology's yearly intention to provide interested readers appropriate summaries of investigations touching the areas of tissue biology, developmental biology, the biology of the immune system, stem cell research, the biology of subcellular compartments, in order to put the message of such studies into natural scientific-/human- and also pathological-relevant correlations.

  1. Biology of Schwann cells.

    Science.gov (United States)

    Kidd, Grahame J; Ohno, Nobuhiko; Trapp, Bruce D

    2013-01-01

    The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate. Copyright © 2013 Elsevier B.V. All rights

  2. Mesangial cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Abboud, Hanna E., E-mail: Abboud@uthscsa.edu

    2012-05-15

    Mesangial cells originate from the metanephric mesenchyme and maintain structural integrity of the glomerular microvascular bed and mesangial matrix homeostasis. In response to metabolic, immunologic or hemodynamic injury, these cells undergo apoptosis or acquire an activated phenotype and undergo hypertrophy, proliferation with excessive production of matrix proteins, growth factors, chemokines and cytokines. These soluble factors exert autocrine and paracrine effects on the cells or on other glomerular cells, respectively. MCs are primary targets of immune-mediated glomerular diseases such as IGA nephropathy or metabolic diseases such as diabetes. MCs may also respond to injury that primarily involves podocytes and endothelial cells or to structural and genetic abnormalities of the glomerular basement membrane. Signal transduction and oxidant stress pathways are activated in MCs and likely represent integrated input from multiple mediators. Such responses are convenient targets for therapeutic intervention. Studies in cultured MCs should be supplemented with in vivo studies as well as examination of freshly isolated cells from normal and diseases glomeruli. In addition to ex vivo morphologic studies in kidney cortex, cells should be studied in their natural environment, isolated glomeruli or even tissue slices. Identification of a specific marker of MCs should help genetic manipulation as well as selective therapeutic targeting of these cells. Identification of biological responses of MCs that are not mediated by the renin–angiotensin system should help development of novel and effective therapeutic strategies to treat diseases characterized by MC pathology.

  3. Fluorescence nanoscopy in cell biology.

    Science.gov (United States)

    Sahl, Steffen J; Hell, Stefan W; Jakobs, Stefan

    2017-09-06

    Fluorescence nanoscopy uniquely combines minimally invasive optical access to the internal nanoscale structure and dynamics of cells and tissues with molecular detection specificity. While the basic physical principles of 'super-resolution' imaging were discovered in the 1990s, with initial experimental demonstrations following in 2000, the broad application of super-resolution imaging to address cell-biological questions has only more recently emerged. Nanoscopy approaches have begun to facilitate discoveries in cell biology and to add new knowledge. One current direction for method improvement is the ambition to quantitatively account for each molecule under investigation and assess true molecular colocalization patterns via multi-colour analyses. In pursuing this goal, the labelling of individual molecules to enable their visualization has emerged as a central challenge. Extending nanoscale imaging into (sliced) tissue and whole-animal contexts is a further goal. In this Review we describe the successes to date and discuss current obstacles and possibilities for further development.

  4. Illuminating Cell Biology

    Science.gov (United States)

    2002-01-01

    NASA's Ames Research Center awarded Ciencia, Inc., a Small Business Innovation Research contract to develop the Cell Fluorescence Analysis System (CFAS) to address the size, mass, and power constraints of using fluorescence spectroscopy in the International Space Station's Life Science Research Facility. The system will play an important role in studying biological specimen's long-term adaptation to microgravity. Commercial applications for the technology include diverse markets such as food safety, in situ environmental monitoring, online process analysis, genomics and DNA chips, and non-invasive diagnostics. Ciencia has already sold the system to the private sector for biosensor applications.

  5. Biology. Teacher's Guide. Investigations in Natural Science.

    Science.gov (United States)

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This teaching guide is designed for use with the 18 biology investigations found in the student manual. These investigations focus on concepts related to:…

  6. One-pot, green synthesis of gold nanoparticles by gelatin and investigation of their biological effects on Osteoblast cells.

    Science.gov (United States)

    Suarasan, Sorina; Focsan, Monica; Soritau, Olga; Maniu, Dana; Astilean, Simion

    2015-08-01

    It is useful to find new methods to synthesize and, more importantly, to control the size and shape of gold nanoparticles (AuNPs) without using relatively toxic-reducing agents and surfactants. In this work, we present a one-pot, green synthesis of AuNPs taking the advantage of gelatin biopolymer to operate as unique reducing, growth controlling and stabilizing agent in aqueous solution of tetrachloroauric acid (HAuCl4) at temperatures above its melting point (∼35°C). The shape and size of AuNPs were found to be strongly influenced by the gelatin concentration (0.5-5%), while the growth rate of AuNPs is controlled by temperature of synthesis (40-80°C) and viscosity of the biopolymer. A specific class of gelatin-coated AuNPs was selected to investigate its stability in simulated physiological conditions and cellular media and subsequently to evaluate the in vitro biocompatibility and capacity to sustain proliferation and differentiation of Osteoblast cells. Dark-field microscopy and Rayleigh scattering spectra prove a more efficient internalization of gelatin-coated AuNPs as compared with citrate-coated AuNPs, while methylthiazoltetrazolium bromide (MTT) assay demonstrates enhanced cell proliferation. Interestingly, in the presence of gelatin-coated AuNPs, we find out a first sign of Osteoblast cells differentiation with bone nodules formation, as confirmed by alkaline phosphatase (ALP) activity assay.

  7. Networks in Cell Biology

    Science.gov (United States)

    Buchanan, Mark; Caldarelli, Guido; De Los Rios, Paolo; Rao, Francesco; Vendruscolo, Michele

    2010-05-01

    Introduction; 1. Network views of the cell Paolo De Los Rios and Michele Vendruscolo; 2. Transcriptional regulatory networks Sarath Chandra Janga and M. Madan Babu; 3. Transcription factors and gene regulatory networks Matteo Brilli, Elissa Calistri and Pietro Lió; 4. Experimental methods for protein interaction identification Peter Uetz, Björn Titz, Seesandra V. Rajagopala and Gerard Cagney; 5. Modeling protein interaction networks Francesco Rao; 6. Dynamics and evolution of metabolic networks Daniel Segré; 7. Hierarchical modularity in biological networks: the case of metabolic networks Erzsébet Ravasz Regan; 8. Signalling networks Gian Paolo Rossini; Appendix 1. Complex networks: from local to global properties D. Garlaschelli and G. Caldarelli; Appendix 2. Modelling the local structure of networks D. Garlaschelli and G. Caldarelli; Appendix 3. Higher-order topological properties S. Ahnert, T. Fink and G. Caldarelli; Appendix 4. Elementary mathematical concepts A. Gabrielli and G. Caldarelli; References.

  8. Biology. Student Investigations and Readings. Investigations in Natural Science.

    Science.gov (United States)

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This student manual contains the 18 biology investigations. These investigations focus on concepts related to: organisms; classification; populations;…

  9. DNA Barcoding Investigations Bring Biology to Life

    Science.gov (United States)

    Musante, Susan

    2010-01-01

    This article describes how DNA barcoding investigations bring biology to life. Biologists recognize the power of DNA barcoding not just to teach biology through connections to the real world but also to immerse students in the exciting process of science. As an investigator in the Program for the Human Environment at Rockefeller University in New…

  10. DNA Barcoding Investigations Bring Biology to Life

    Science.gov (United States)

    Musante, Susan

    2010-01-01

    This article describes how DNA barcoding investigations bring biology to life. Biologists recognize the power of DNA barcoding not just to teach biology through connections to the real world but also to immerse students in the exciting process of science. As an investigator in the Program for the Human Environment at Rockefeller University in New…

  11. Mammalian synthetic biology for studying the cell.

    Science.gov (United States)

    Mathur, Melina; Xiang, Joy S; Smolke, Christina D

    2017-01-02

    Synthetic biology is advancing the design of genetic devices that enable the study of cellular and molecular biology in mammalian cells. These genetic devices use diverse regulatory mechanisms to both examine cellular processes and achieve precise and dynamic control of cellular phenotype. Synthetic biology tools provide novel functionality to complement the examination of natural cell systems, including engineered molecules with specific activities and model systems that mimic complex regulatory processes. Continued development of quantitative standards and computational tools will expand capacities to probe cellular mechanisms with genetic devices to achieve a more comprehensive understanding of the cell. In this study, we review synthetic biology tools that are being applied to effectively investigate diverse cellular processes, regulatory networks, and multicellular interactions. We also discuss current challenges and future developments in the field that may transform the types of investigation possible in cell biology. © 2017 Mathur et al.

  12. Diffuse large B-cell lymphoma associated with the use of biologic and other investigational agents: the importance of long-term post-marketing safety surveillance.

    Science.gov (United States)

    Goddard, Allison; Borovicka, Judy H; West, Dennis P; Evens, Andrew M; Laumann, Anne

    2011-01-01

    This case report describes a patient who developed diffuse large B-cell lymphoma (DLBCL) after receiving courses of two investigational biologic agents and cyclosporine followed by more than four years of subcutaneous efalizumab for the treatment of extensive chronic plaque psoriasis. Three years later, the patient remains free of lymphoma and his psoriasis is well controlled with thrice-weekly narrow-band ultraviolet phototherapy. This case emphasizes the importance of continued long-term post-marketing safety surveillance and the early reporting of all possible serious side effects, including cancers, related to the use of any newly available product. In particular, surveillance should focus on the immunomodulating biologic agents in order to identify possible dangerous sequelae.

  13. Using Affinity Chromatography to Investigate Novel Protein-Protein Interactions in an Undergraduate Cell and Molecular Biology Lab Course

    Science.gov (United States)

    Belanger, Kenneth D.

    2009-01-01

    Inquiry-driven lab exercises require students to think carefully about a question, carry out an investigation of that question, and critically analyze the results of their investigation. Here, we describe the implementation and assessment of an inquiry-based laboratory exercise in which students obtain and analyze novel data that contribute to our…

  14. Fostering synergy between cell biology and systems biology

    OpenAIRE

    2015-01-01

    In the shared pursuit of elucidating detailed mechanisms of cell function, systems biology presents a natural complement to ongoing efforts in cell biology. Systems biology aims to characterize biological systems through integrated and quantitative modeling of cellular information. The process of model building and analysis provides value through synthesizing and cataloging information about cells and molecules; predicting mechanisms and identifying generalizable themes; generating hypotheses...

  15. Mechanics rules cell biology

    Directory of Open Access Journals (Sweden)

    Wang James HC

    2010-07-01

    Full Text Available Abstract Cells in the musculoskeletal system are subjected to various mechanical forces in vivo. Years of research have shown that these mechanical forces, including tension and compression, greatly influence various cellular functions such as gene expression, cell proliferation and differentiation, and secretion of matrix proteins. Cells also use mechanotransduction mechanisms to convert mechanical signals into a cascade of cellular and molecular events. This mini-review provides an overview of cell mechanobiology to highlight the notion that mechanics, mainly in the form of mechanical forces, dictates cell behaviors in terms of both cellular mechanobiological responses and mechanotransduction.

  16. Molecular biology of the cell

    CERN Document Server

    Alberts, Bruce; Lewis, Julian

    2000-01-01

    Molecular Biology of the Cell is the classic in-dept text reference in cell biology. By extracting the fundamental concepts from this enormous and ever-growing field, the authors tell the story of cell biology, and create a coherent framework through which non-expert readers may approach the subject. Written in clear and concise language, and beautifully illustrated, the book is enjoyable to read, and it provides a clear sense of the excitement of modern biology. Molecular Biology of the Cell sets forth the current understanding of cell biology (completely updated as of Autumn 2001), and it explores the intriguing implications and possibilities of the great deal that remains unknown. The hallmark features of previous editions continue in the Fourth Edition. The book is designed with a clean and open, single-column layout. The art program maintains a completely consistent format and style, and includes over 1,600 photographs, electron micrographs, and original drawings by the authors. Clear and concise concept...

  17. Biological atomism and cell theory.

    Science.gov (United States)

    Nicholson, Daniel J

    2010-09-01

    Biological atomism postulates that all life is composed of elementary and indivisible vital units. The activity of a living organism is thus conceived as the result of the activities and interactions of its elementary constituents, each of which individually already exhibits all the attributes proper to life. This paper surveys some of the key episodes in the history of biological atomism, and situates cell theory within this tradition. The atomistic foundations of cell theory are subsequently dissected and discussed, together with the theory's conceptual development and eventual consolidation. This paper then examines the major criticisms that have been waged against cell theory, and argues that these too can be interpreted through the prism of biological atomism as attempts to relocate the true biological atom away from the cell to a level of organization above or below it. Overall, biological atomism provides a useful perspective through which to examine the history and philosophy of cell theory, and it also opens up a new way of thinking about the epistemic decomposition of living organisms that significantly departs from the physicochemical reductionism of mechanistic biology.

  18. When cell biology meets theory

    Science.gov (United States)

    Gonzalez-Gaitan, Marcos

    2015-01-01

    Cell biologists now have tools and knowledge to generate useful quantitative data. But how can we make sense of these data, and are we measuring the correct parameters? Moreover, how can we test hypotheses quantitatively? To answer these questions, the theory of physics is required and is essential to the future of quantitative cell biology. PMID:26416957

  19. When cell biology meets theory.

    Science.gov (United States)

    Gonzalez-Gaitan, Marcos; Roux, Aurélien

    2015-09-28

    Cell biologists now have tools and knowledge to generate useful quantitative data. But how can we make sense of these data, and are we measuring the correct parameters? Moreover, how can we test hypotheses quantitatively? To answer these questions, the theory of physics is required and is essential to the future of quantitative cell biology.

  20. A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

    Science.gov (United States)

    Hood-DeGrenier, Jennifer K.

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

  1. A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

    Science.gov (United States)

    Hood-DeGrenier, Jennifer K.

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

  2. A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells.

    Science.gov (United States)

    Alrifaiy, Ahmed; Borg, Johan; Lindahl, Olof A; Ramser, Kerstin

    2015-04-18

    The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.

  3. The evolving biology of cell reprogramming

    OpenAIRE

    Wilmut, Ian; Sullivan, Gareth; Chambers, Ian

    2011-01-01

    Modern stem cell biology has achieved a transformation that was thought by many to be every bit as unattainable as the ancient alchemists' dream of transforming base metals into gold. Exciting opportunities arise from the process known as ‘cellular reprogramming’ in which cells can be reliably changed from one tissue type to another. This is enabling novel approaches to more deeply investigate the fundamental basis of cell identity. In addition, new opportunities have also been created to stu...

  4. Teaching Cell Biology in Primary Schools

    Directory of Open Access Journals (Sweden)

    Francele de Abreu Carlan

    2014-01-01

    Full Text Available Basic concepts of cell biology are essential for scientific literacy. However, because many aspects of cell theory and cell functioning are quite abstract, students experience difficulties understanding them. In this study, we investigated whether diverse teaching resources such as the use of replicas of Leeuwenhoek’s microscope, visualization of cells using an optical microscope, construction of three-dimensional cell models, and reading of a comic book about cells could mitigate the difficulties encountered when teaching cell biology to 8th-grade primary school students. The results suggest that these didactic activities improve students’ ability to learn concrete concepts about cell biology, such as the composition of living beings, growth, and cicatrization. Also, the development of skills was observed, as, for example, the notion of cell size. However, no significant improvements were observed in students’ ability to learn about abstract topics, such as the structures of subcellular organelles and their functions. These results suggest that many students in this age have not yet concluded Piaget’s concrete operational stage, indicating that the concepts required for the significant learning of abstract subjects need to be explored more thoroughly in the process of designing programs that introduce primary school students to cell biology.

  5. Rhomboids, signalling and cell biology.

    Science.gov (United States)

    Freeman, Matthew

    2016-06-15

    Here, I take a somewhat personal perspective on signalling control, focusing on the rhomboid-like superfamily of proteins that my group has worked on for almost 20 years. As well as describing some of the key and recent advances, I attempt to draw out signalling themes that emerge. One important message is that the genetic and biochemical perspective on signalling has tended to underplay the importance of cell biology. There is clear evidence that signalling pathways exploit the control of intracellular trafficking, protein quality control and degradation and other cell biological phenomena, as important regulatory opportunities.

  6. Cell biology of neuronal endocytosis.

    Science.gov (United States)

    Parton, R G; Dotti, C G

    1993-09-01

    Endocytosis is the process by which cells take in fluid and components of the plasma membrane. In this way cells obtain nutrients and trophic factors, retrieve membrane proteins for degradation, and sample their environment. In neuronal cells endocytosis is essential for the recycling of membrane after neurotransmitter release and plays a critical role during early developmental stages. Moreover, alterations of the endocytic pathway have been attributed a crucial role in the pathophysiology of certain neurological diseases. Although well characterized at the ultrastructural level, little is known of the dynamics and molecular organization of the neuronal endocytic pathways. In this respect most of our knowledge comes from studies of non-neuronal cells. In this review we will examine the endocytic pathways in neurons from a cell biological viewpoint by making comparisons with non-neuronal cells and in particular with another polarized cell, the epithelial cell.

  7. Cell biology of fat storage.

    Science.gov (United States)

    Cohen, Paul; Spiegelman, Bruce M

    2016-08-15

    The worldwide epidemic of obesity and type 2 diabetes has greatly increased interest in the biology and physiology of adipose tissues. Adipose (fat) cells are specialized for the storage of energy in the form of triglycerides, but research in the last few decades has shown that fat cells also play a critical role in sensing and responding to changes in systemic energy balance. White fat cells secrete important hormone-like molecules such as leptin, adiponectin, and adipsin to influence processes such as food intake, insulin sensitivity, and insulin secretion. Brown fat, on the other hand, dissipates chemical energy in the form of heat, thereby defending against hypothermia, obesity, and diabetes. It is now appreciated that there are two distinct types of thermogenic fat cells, termed brown and beige adipocytes. In addition to these distinct properties of fat cells, adipocytes exist within adipose tissue, where they are in dynamic communication with immune cells and closely influenced by innervation and blood supply. This review is intended to serve as an introduction to adipose cell biology and to familiarize the reader with how these cell types play a role in metabolic disease and, perhaps, as targets for therapeutic development.

  8. The cell biology of aging

    Science.gov (United States)

    DiLoreto, Race; Murphy, Coleen T.

    2015-01-01

    One of the original hypotheses of organismal longevity posits that aging is the natural result of entropy on the cells, tissues, and organs of the animal—a slow, inexorable slide into nonfunctionality caused by stochastic degradation of its parts. We now have evidence that aging is instead at least in part genetically regulated. Many mutations have been discovered to extend lifespan in organisms of all complexities, from yeast to mammals. The study of metazoan model organisms, such as Caenorhabditis elegans, has been instrumental in understanding the role of genetics in the cell biology of aging. Longevity mutants across the spectrum of model organisms demonstrate that rates of aging are regulated through genetic control of cellular processes. The regulation and subsequent breakdown of cellular processes represent a programmatic decision by the cell to either continue or abandon maintenance procedures with age. Our understanding of cell biological processes involved in regulating aging have been particularly informed by longevity mutants and treatments, such as reduced insulin/IGF-1 signaling and dietary restriction, which are critical in determining the distinction between causes of and responses to aging and have revealed a set of downstream targets that participate in a range of cell biological activities. Here we briefly review some of these important cellular processes. PMID:26668170

  9. Wnt Signaling in Cancer Stem Cell Biology.

    Science.gov (United States)

    de Sousa E Melo, Felipe; Vermeulen, Louis

    2016-06-27

    Aberrant regulation of Wnt signaling is a common theme seen across many tumor types. Decades of research have unraveled the epigenetic and genetic alterations that result in elevated Wnt pathway activity. More recently, it has become apparent that Wnt signaling levels identify stem-like tumor cells that are responsible for fueling tumor growth. As therapeutic targeting of these tumor stem cells is an intense area of investigation, a concise understanding on how Wnt activity relates to cancer stem cell traits is needed. This review attempts at summarizing the intricacies between Wnt signaling and cancer stem cell biology with a special emphasis on colorectal cancer.

  10. Photoactive molecules for applications in molecular imaging and cell biology.

    Science.gov (United States)

    Shao, Qing; Xing, Bengang

    2010-08-01

    Photoactive technology has proven successful for non-invasive regulation of biological activities and processes in living cells. With the light-directed generation of biomaterials or signals, mechanisms in cell biology can be investigated at the molecular level with spatial and temporal resolution. In this tutorial review, we aim to introduce the important applications of photoactive molecules for elucidating cell biology on aspects of protein engineering, fluorescence labelling, gene regulation and cell physiological functions.

  11. Prion potency in stem cells biology.

    Science.gov (United States)

    Lopes, Marilene H; Santos, Tiago G

    2012-01-01

    Prion protein (PrP) can be considered a pivotal molecule because it interacts with several partners to perform a diverse range of critical biological functions that might differ in embryonic and adult cells. In recent years, there have been major advances in elucidating the putative role of PrP in the basic biology of stem cells in many different systems. Here, we review the evidence indicating that PrP is a key molecule involved in driving different aspects of the potency of embryonic and tissue-specific stem cells in self-perpetuation and differentiation in many cell types. It has been shown that PrP is involved in stem cell self-renewal, controlling pluripotency gene expression, proliferation, and neural and cardiomyocyte differentiation. PrP also has essential roles in distinct processes that regulate tissue-specific stem cell biology in nervous and hematopoietic systems and during muscle regeneration. Results from our own investigations have shown that PrP is able to modulate self-renewal and proliferation in neural stem cells, processes that are enhanced by PrP interactions with stress inducible protein 1 (STI1). Thus, the available data reveal the influence of PrP in acting upon the maintenance of pluripotent status or the differentiation of stem cells from the early embryogenesis through adulthood.

  12. Stochastic processes in cell biology

    CERN Document Server

    Bressloff, Paul C

    2014-01-01

    This book develops the theory of continuous and discrete stochastic processes within the context of cell biology.  A wide range of biological topics are covered including normal and anomalous diffusion in complex cellular environments, stochastic ion channels and excitable systems, stochastic calcium signaling, molecular motors, intracellular transport, signal transduction, bacterial chemotaxis, robustness in gene networks, genetic switches and oscillators, cell polarization, polymerization, cellular length control, and branching processes. The book also provides a pedagogical introduction to the theory of stochastic process – Fokker Planck equations, stochastic differential equations, master equations and jump Markov processes, diffusion approximations and the system size expansion, first passage time problems, stochastic hybrid systems, reaction-diffusion equations, exclusion processes, WKB methods, martingales and branching processes, stochastic calculus, and numerical methods.   This text is primarily...

  13. Investigating Coccolithophorid Biology in the Sedimentary Laboratory

    Science.gov (United States)

    McClelland, H. L. O.; Barbarin, N.; Beaufort, L.; Hermoso, M.; Rickaby, R. E. M.

    2014-12-01

    Coccolithophores are the ocean's dominant calcifying phytoplankton; they play an important, but poorly understood, role in long-term biogeochemical climatic feedbacks. Calcite producing marine organisms are likely to calcify less in a future world where higher carbon dioxide concentrations will lead to ocean acidification (OA), but coccolithophores may be the exception. In coccolithophores calcification occurs in an intracellular vesicle, where the site of calcite precipitation is buffered from the external environment and is subject to a uniquely high degree of biological control. Culture manipulation experiments mimicking the effects of OA in the laboratory have yielded empirical evidence for phenotypic plasticity, competition and evolutionary adaptation in asexual populations. However, the extent to which these results are representative of natural populations, and of the response over timescales of greater than a few hundred generations, is unclear. Here we describe a new sediment-based proxy for the PIC:POC (particulate inorganic to particulate organic carbon ratio) of coccolithophore biomass, which is equivalent to the fractional energy contribution to calcification at constant pH, and a biologically meaningful measure of the organism's tendency to calcify. Employing the geological record as a laboratory, we apply this proxy to sedimentary material from the southern Pacific Ocean to investigate the integrated response of real ancient coccolithophore populations to environmental change over many thousands of years. Our results provide a new perspective on phenotypic change in real populations of coccolithophorid algae over long timescales.

  14. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules...... of this review include the stoichiometry and dynamics of recombination complexes in vivo, the choreography of assembly and disassembly of recombination proteins at sites of DNA damage, the mobilization of damaged DNA during homology search, and the functional compartmentalization of the nucleus with respect...... as well as the cellular organization of the process of homologous recombination. Herein we review the cell biological aspects of mitotic homologous recombination with a focus on Saccharomyces cerevisiae and mammalian cells, but will also draw on findings from other experimental systems. Key topics...

  15. Basic statistics in cell biology.

    Science.gov (United States)

    Vaux, David L

    2014-01-01

    The physicist Ernest Rutherford said, "If your experiment needs statistics, you ought to have done a better experiment." Although this aphorism remains true for much of today's research in cell biology, a basic understanding of statistics can be useful to cell biologists to help in monitoring the conduct of their experiments, in interpreting the results, in presenting them in publications, and when critically evaluating research by others. However, training in statistics is often focused on the sophisticated needs of clinical researchers, psychologists, and epidemiologists, whose conclusions depend wholly on statistics, rather than the practical needs of cell biologists, whose experiments often provide evidence that is not statistical in nature. This review describes some of the basic statistical principles that may be of use to experimental biologists, but it does not cover the sophisticated statistics needed for papers that contain evidence of no other kind.

  16. Atomic force microscopy in cell biology

    Institute of Scientific and Technical Information of China (English)

    LU Zhexue; ZHANG Zhiling; PANG Daiwen

    2005-01-01

    The history, characteristic, operation modes and coupling techniques of atomic force microscopy (AFM) are introduced. Then the application in cell biology is reviewed in four aspects: cell immobilization methods, cell imaging, force spectrum study and cell manipulation. And the prospect of AFM application in cell biology is discussed.

  17. Biological significance of DNA adducts investigated by simultaneous analysis of different endpoints of genotoxicity in L5178Y mouse lymphoma cells treated with methyl methanesulfonate.

    Science.gov (United States)

    Brink, Andreas; Schulz, Berta; Stopper, Helga; Lutz, Werner K

    2007-12-01

    The biological significance of DNA adducts is under continuous discussion because analytical developments allow determination of adducts at ever lower levels. Central questions refer to the biological consequences of adducts and to the relationship between background DNA damage and exposure-related increments. These questions were addressed by measuring the two DNA adducts 7-methylguanine (7-mG) and O(6)-methyl-2'-deoxyguanosine (O(6)-mdGuo) by LC-MS/MS in parallel to two biological endpoints of genotoxicity (comet assay and in vitro micronucleus test), using large batches of L5178Y mouse lymphoma cells treated with methyl methanesulfonate (MMS). The background level of 7-mG was 1440 adducts per 10(9) nucleotides while O(6)-mdGuo was almost 50-fold lower (32 adducts per 10(9) nucleotides). In the comet assay and the micronucleus test, background was in the usual range seen with smaller batches of cells (2.1% Tail DNA and 12 micronuclei-containing cells per 1000 binucleated cells, respectively). For the comparison of the four endpoints for dose-related increments above background in the low-response region we assumed linearity at low dose and used the concept of the "doubling dose", i.e., we estimated the concentration of MMS necessary to double the background measures. Doubling doses of 4.3 and 8.7microM MMS were deduced for 7-mG and O(6)-mdGuo, respectively. For doubling the background measures in the comet assay and the micronucleus test, 5 to 15-fold higher concentrations of MMS were necessary (45 and 66microM, respectively). This means that the contribution of an increase in DNA methylation to biological endpoints of genotoxicity is overestimated. For xenobiotics that generate adducts without background, the difference is even more pronounced because the dose-response curve starts at zero and the limit of detection of an increase is not affected by background variation. Consequences for the question of thresholds in dose-response relationships and for the

  18. Fostering synergy between cell biology and systems biology.

    Science.gov (United States)

    Eddy, James A; Funk, Cory C; Price, Nathan D

    2015-08-01

    In the shared pursuit of elucidating detailed mechanisms of cell function, systems biology presents a natural complement to ongoing efforts in cell biology. Systems biology aims to characterize biological systems through integrated and quantitative modeling of cellular information. The process of model building and analysis provides value through synthesizing and cataloging information about cells and molecules, predicting mechanisms and identifying generalizable themes, generating hypotheses and guiding experimental design, and highlighting knowledge gaps and refining understanding. In turn, incorporating domain expertise and experimental data is crucial for building towards whole cell models. An iterative cycle of interaction between cell and systems biologists advances the goals of both fields and establishes a framework for mechanistic understanding of the genome-to-phenome relationship. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  19. Emerging molecular approaches in stem cell biology.

    Science.gov (United States)

    Jaishankar, Amritha; Vrana, Kent

    2009-04-01

    Stem cells are characterized by their ability to self-renew and differentiate into multiple adult cell types. Although substantial progress has been made over the last decade in understanding stem cell biology, recent technological advances in molecular and systems biology may hold the key to unraveling the mystery behind stem cell self-renewal and plasticity. The most notable of these advances is the ability to generate induced pluripotent cells from somatic cells. In this review, we discuss our current understanding of molecular similarities and differences among various stem cell types. Moreover, we survey the current state of systems biology and forecast future needs and direction in the stem cell field.

  20. Integrating cell biology and proteomic approaches in plants.

    Science.gov (United States)

    Takáč, Tomáš; Šamajová, Olga; Šamaj, Jozef

    2017-04-22

    Significant improvements of protein extraction, separation, mass spectrometry and bioinformatics nurtured advancements of proteomics during the past years. The usefulness of proteomics in the investigation of biological problems can be enhanced by integration with other experimental methods from cell biology, genetics, biochemistry, pharmacology, molecular biology and other omics approaches including transcriptomics and metabolomics. This review aims to summarize current trends integrating cell biology and proteomics in plant science. Cell biology approaches are most frequently used in proteomic studies investigating subcellular and developmental proteomes, however, they were also employed in proteomic studies exploring abiotic and biotic stress responses, vesicular transport, cytoskeleton and protein posttranslational modifications. They are used either for detailed cellular or ultrastructural characterization of the object subjected to proteomic study, validation of proteomic results or to expand proteomic data. In this respect, a broad spectrum of methods is employed to support proteomic studies including ultrastructural electron microscopy studies, histochemical staining, immunochemical localization, in vivo imaging of fluorescently tagged proteins and visualization of protein-protein interactions. Thus, cell biological observations on fixed or living cell compartments, cells, tissues and organs are feasible, and in some cases fundamental for the validation and complementation of proteomic data. Validation of proteomic data by independent experimental methods requires development of new complementary approaches. Benefits of cell biology methods and techniques are not sufficiently highlighted in current proteomic studies. This encouraged us to review most popular cell biology methods used in proteomic studies and to evaluate their relevance and potential for proteomic data validation and enrichment of purely proteomic analyses. We also provide examples of

  1. Effect of different biological activity collagen scaffolds on growth ability of human dental pulp cells and investigation of its possible molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Yu-Hong Zou

    2015-01-01

    Objective:To study the effect of different biological activity collagen scaffolds on growth ability of human dental pulp cells and its possible molecular mechanisms.Methods:Human dental pulp cells were isolated and cultured, seeded on collagen scaffold (COL), collagen-bioactive glass scaffolds (COL-BG) and collagen-bioactive glass-PCL scaffolds (COL-BG-PCL). Then growth ability of the cells and expression of related genes were detected.Results:hDPSCs absorbance value, migration rate as well as ALP content in supernatant of COL-BG-PCL group were all higher than those of COL group and COL-BG group; Oct4A, NICD, HMGB1, SDF1, DSPP and DMP-1 contents of COL-BG-PCL group were all higher than those of COL group and COL-BG group.Conclusion:COL-BG-PCL composites contribute to proliferation, migration and differentiation of hDPSCs; the possible molecular mechanisms are increasing Oct4A, NICD, HMGB1, SDF1, DSPP and DMP-1 expression.

  2. Investigative cases and student outcomes in an upper-division cell and molecular biology laboratory course at a minority-serving institution.

    Science.gov (United States)

    Knight, Jonathan D; Fulop, Rebecca M; Márquez-Magaña, Leticia; Tanner, Kimberly D

    2008-01-01

    Active-learning strategies are increasingly being integrated into college-level science courses to make material more accessible to all students and to improve learning outcomes. One active-learning pedagogy, case-based learning (CBL), was developed as a way to both enhance engagement in the material and to accommodate diverse learning styles. Yet, adoption of CBL approaches in undergraduate biology courses has been piecemeal, in part because of the perceived investment of time required. Furthermore, few CBL lesson plans have been developed specifically for upper-division laboratory courses. Here, we describe four cases that we developed and implemented for a senior cell and molecular biology laboratory course at San Francisco State University, a minority-serving institution. To evaluate the effectiveness of these modules, we used both written and verbal assessments to gauge learning outcomes and attitudinal responses of students over two semesters. Students responded positively to the new approach and seemed to meet the learning goals for the course. Most said they would take a course using CBL again. These case modules are readily adaptable to a variety of classroom settings.

  3. Investigations of the Biological Effects of Airborne and Inhalable Substances by Cell-Based In Vitro Methods: Fundamental Improvements to the ALI Concept

    Directory of Open Access Journals (Sweden)

    Detlef Ritter

    2014-01-01

    Full Text Available The state of the art for cell-based in vitro investigations of airborne and inhalable material is “air-liquid interface” (ALI technology. Cell lines, primary cells, complex 3D models, or precision-cut lung slices (PCLS are used to represent the lung or skin by way of an in vitro barrier model. These models have been applied in toxicity or pharmacological testing. However, contrasting with a clear demand for alternative methods, there is still no widely accepted procedure for cell-based in vitro testing of inhalable substances. In the light of this, an analysis was undertaken of common drawbacks of current approaches. Hence, the pivotal improvements aimed at were the cellular exposure environment, overall performance and applicability, operability of online investigations during exposure and routine setup. It resulted in an improved device (P.R.I.T. ExpoCube based on an “all-in-one-plate” concept including all phases of the experiment (cell culture, exposure, and read-out and all experimental groups (two test gas groups, controls in one single commercial multiwell plate. Verification of the concept was demonstrated in a first experimental series using reference substances (formaldehyde, ozone, and clean air. The resulting ALI procedure enables the application of inhalable substances and mixtures under highly effective exposure conditions in routine utilization.

  4. Investigation on biological characteristics of human amniotic fluid-derived stem cells%人羊水来源干细胞生物学性状的研究

    Institute of Scientific and Technical Information of China (English)

    张建芳; 顾潇; 陈必良

    2011-01-01

    Objective: Human amniotic fluid samples were isolated and cultured in vitro.To establish in vitro culture procedure of amniotic fluid-derived stem cells (AFS) and to study their biological characteristics.Methods: AFS were isolated from second-trimester amniotic fluid by adherence.The phenotypes of AFS were detected by flow cytometry and RT-PCR.Results: Primary cells grow slowly, The cells proliferated rapidly after passage and they were positive for CD29, CD44, CD105 and negative for CD45 and CD133 by flow cytometry.RT-PCR analysis showed that AFS were positive for Oct-4 and Nanog.Conclusion: Experiment has successfully isolated stem cells in amniotic fluid.The stem cells isolated from second-trimester amniotic fluid have a great potential of proliferation, which express mesenchymal stem cell markers.Their characteristics are in accord with mesenchymal stem cells.%目的 对人羊水标本进行体外分离培养,建立人羊水来源干细胞的体外培养体系,对其生物学形状进行研究.方法 贴壁法体外分离获得人羊水来源干细胞,多次传代扩增后,采用流式细胞仪和RT-PCR技术检测细胞表面抗原的表达.结果 羊水干细胞原代生长较慢,传代后生长迅速,体外倍增时间约36h,流式细胞仪检测证实细胞表达CD29、CD44、CD105等间充质干细胞标志,不表达造血干细胞标志CD45和CD133.RT-PCR检测显示羊水干细胞表达Oct-4、Nanog基因.结论 实验成功分离获得羊水中具有干细胞性质的细胞群,采用贴壁法分离获得的干细胞体外增殖能力强,表达间充质干细胞表面标志,符合间充质干细胞的特点.

  5. Studying cell biology in the skin

    Science.gov (United States)

    Morrow, Angel; Lechler, Terry

    2015-01-01

    Advances in cell biology have often been driven by studies in diverse organisms and cell types. Although there are technical reasons for why different cell types are used, there are also important physiological reasons. For example, ultrastructural studies of vesicle transport were aided by the use of professional secretory cell types. The use of tissues/primary cells has the advantage not only of using cells that are adapted to the use of certain cell biological machinery, but also of highlighting the physiological roles of this machinery. Here we discuss advantages of the skin as a model system. We discuss both advances in cell biology that used the skin as a driving force and future prospects for use of the skin to understand basic cell biology. A unique combination of characteristics and tools makes the skin a useful in vivo model system for many cell biologists. PMID:26564861

  6. A Western blot-based investigation of the yeast secretory pathway designed for an intermediate-level undergraduate cell biology laboratory.

    Science.gov (United States)

    Hood-Degrenier, Jennifer K

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in two distinct steps of protein secretion were differentiated using a genetic reporter designed specifically to identify defects in the first step of the pathway, the insertion of proteins into the endoplasmic reticulum (Vallen, 2002). We have developed two versions of a Western blotting assay that serves as a second way of distinguishing the two secretory mutants, which we pair with the genetic assay in a 3-wk laboratory module. A quiz administered before and after students participated in the lab activities revealed significant postlab gains in their understanding of the secretory pathway and experimental techniques used to study it. A second survey administered at the end of the lab module assessed student perceptions of the efficacy of the lab activities; the results of this survey indicated that the experiments were successful in meeting a set of educational goals defined by the instructor.

  7. Evolutionary cell biology: two origins, one objective.

    Science.gov (United States)

    Lynch, Michael; Field, Mark C; Goodson, Holly V; Malik, Harmit S; Pereira-Leal, José B; Roos, David S; Turkewitz, Aaron P; Sazer, Shelley

    2014-12-02

    All aspects of biological diversification ultimately trace to evolutionary modifications at the cellular level. This central role of cells frames the basic questions as to how cells work and how cells come to be the way they are. Although these two lines of inquiry lie respectively within the traditional provenance of cell biology and evolutionary biology, a comprehensive synthesis of evolutionary and cell-biological thinking is lacking. We define evolutionary cell biology as the fusion of these two eponymous fields with the theoretical and quantitative branches of biochemistry, biophysics, and population genetics. The key goals are to develop a mechanistic understanding of general evolutionary processes, while specifically infusing cell biology with an evolutionary perspective. The full development of this interdisciplinary field has the potential to solve numerous problems in diverse areas of biology, including the degree to which selection, effectively neutral processes, historical contingencies, and/or constraints at the chemical and biophysical levels dictate patterns of variation for intracellular features. These problems can now be examined at both the within- and among-species levels, with single-cell methodologies even allowing quantification of variation within genotypes. Some results from this emerging field have already had a substantial impact on cell biology, and future findings will significantly influence applications in agriculture, medicine, environmental science, and synthetic biology.

  8. Systems Biology and Stem Cell Pluripotency

    DEFF Research Database (Denmark)

    Mashayekhi, Kaveh; Hall, Vanessa; Freude, Kristine

    2016-01-01

    Recent breakthroughs in stem cell biology have accelerated research in the area of regenerative medicine. Over the past years, it has become possible to derive patient-specific stem cells which can be used to generate different cell populations for potential cell therapy. Systems biological...... modeling of stem cell pluripotency and differentiation have largely been based on prior knowledge of signaling pathways, gene regulatory networks, and epigenetic factors. However, there is a great need to extend the complexity of the modeling and to integrate different types of data, which would further...... improve systems biology and its uses in the field. In this chapter, we first give a general background on stem cell biology and regenerative medicine. Stem cell potency is introduced together with the hierarchy of stem cells ranging from pluripotent embryonic stem cells (ESCs) and induced pluripotent stem...

  9. Single cell induced optical confinement in biological lasers

    Science.gov (United States)

    Karl, M.; Dietrich, C. P.; Schubert, M.; Samuel, I. D. W.; Turnbull, G. A.; Gather, M. C.

    2017-03-01

    Biological single cell lasers have shown great potential for fundamental research and next generation sensing applications. In this study, the potential of fluorescent biological cells as refractive index landscapes and active optical elements is investigated using a combined Fourier- and hyperspectral imaging technique. We show that the refractive index contrast between cell and surrounding leads to 3D confinement of photons inside living cells. The Fourier- and real-space emission characteristics of these biological lasers are closely related and can be predicted from one another. Investigations of the lasing threshold for different energy and momentum position in Fourier-space give insight into the fundamental creation of longitudinal and transverse lasing modes within the cell. These findings corroborate the potential of living biological materials for precision engineering of photonic structures and may pave the way towards low threshold polariton lasing from single cells.

  10. Computational Tools for Stem Cell Biology.

    Science.gov (United States)

    Bian, Qin; Cahan, Patrick

    2016-12-01

    For over half a century, the field of developmental biology has leveraged computation to explore mechanisms of developmental processes. More recently, computational approaches have been critical in the translation of high throughput data into knowledge of both developmental and stem cell biology. In the past several years, a new subdiscipline of computational stem cell biology has emerged that synthesizes the modeling of systems-level aspects of stem cells with high-throughput molecular data. In this review, we provide an overview of this new field and pay particular attention to the impact that single cell transcriptomics is expected to have on our understanding of development and our ability to engineer cell fate.

  11. Total synthesis and biological investigation of (-)-promysalin.

    Science.gov (United States)

    Steele, Andrew D; Knouse, Kyle W; Keohane, Colleen E; Wuest, William M

    2015-06-17

    Compounds that specifically target pathogenic bacteria are greatly needed, and identifying the method by which they act would provide new avenues of treatment. Herein we report the concise, high-yielding total synthesis (eight steps, 35% yield) of promysalin, a natural product that displays antivirulence phenotypes against pathogenic bacteria. Guided by bioinformatics, four diastereomers were synthesized, and the relative and absolute stereochemistries were confirmed by spectral and biological analysis. Finally, we show for the first time that promysalin displays two antivirulence phenotypes: the dispersion of mature biofilms and the inhibition of pyoverdine production, hinting at a unique pathogenic-specific mechanism of action.

  12. Label-Free Biosensors for Cell Biology

    Directory of Open Access Journals (Sweden)

    Ye Fang

    2011-01-01

    Full Text Available Label-free biosensors for studying cell biology have finally come of age. Recent developments have advanced the biosensors from low throughput and high maintenance research tools to high throughput and low maintenance screening platforms. In parallel, the biosensors have evolved from an analytical tool solely for molecular interaction analysis to powerful platforms for studying cell biology at the whole cell level. This paper presents historical development, detection principles, and applications in cell biology of label-free biosensors. Future perspectives are also discussed.

  13. Adaptable data management for systems biology investigations

    Directory of Open Access Journals (Sweden)

    Burdick David

    2009-03-01

    Full Text Available Abstract Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry. We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community.

  14. Open source bioimage informatics for cell biology.

    Science.gov (United States)

    Swedlow, Jason R; Eliceiri, Kevin W

    2009-11-01

    Significant technical advances in imaging, molecular biology and genomics have fueled a revolution in cell biology, in that the molecular and structural processes of the cell are now visualized and measured routinely. Driving much of this recent development has been the advent of computational tools for the acquisition, visualization, analysis and dissemination of these datasets. These tools collectively make up a new subfield of computational biology called bioimage informatics, which is facilitated by open source approaches. We discuss why open source tools for image informatics in cell biology are needed, some of the key general attributes of what make an open source imaging application successful, and point to opportunities for further operability that should greatly accelerate future cell biology discovery.

  15. Lipid Rafts in Mast Cell Biology

    Directory of Open Access Journals (Sweden)

    Adriana Maria Mariano Silveira e Souza

    2011-01-01

    Full Text Available Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization.

  16. Studying cell biology in the skin.

    Science.gov (United States)

    Morrow, Angel; Lechler, Terry

    2015-11-15

    Advances in cell biology have often been driven by studies in diverse organisms and cell types. Although there are technical reasons for why different cell types are used, there are also important physiological reasons. For example, ultrastructural studies of vesicle transport were aided by the use of professional secretory cell types. The use of tissues/primary cells has the advantage not only of using cells that are adapted to the use of certain cell biological machinery, but also of highlighting the physiological roles of this machinery. Here we discuss advantages of the skin as a model system. We discuss both advances in cell biology that used the skin as a driving force and future prospects for use of the skin to understand basic cell biology. A unique combination of characteristics and tools makes the skin a useful in vivo model system for many cell biologists. © 2015 Morrow and Lechler. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  17. BIOLOGICALLY INSPIRED HARDWARE CELL ARCHITECTURE

    DEFF Research Database (Denmark)

    2010-01-01

    Disclosed is a system comprising: - a reconfigurable hardware platform; - a plurality of hardware units defined as cells adapted to be programmed to provide self-organization and self-maintenance of the system by means of implementing a program expressed in a programming language defined as DNA...... language, where each cell is adapted to communicate with one or more other cells in the system, and where the system further comprises a converter program adapted to convert keywords from the DNA language to a binary DNA code; where the self-organisation comprises that the DNA code is transmitted to one...... or more of the cells, and each of the one or more cells is adapted to determine its function in the system; where if a fault occurs in a first cell and the first cell ceases to perform its function, self-maintenance is performed by that the system transmits information to the cells that the first cell has...

  18. Chemical approaches to studying stem cell biology

    Institute of Scientific and Technical Information of China (English)

    Wenlin Li; Kai Jiang; Wanguo Wei; Yan Shi; Sheng Ding

    2013-01-01

    Stem cells,including both pluripotent stem cells and multipotent somatic stem cells,hold great potential for interrogating the mechanisms of tissue development,homeostasis and pathology,and for treating numerous devastating diseases.Establishment of in vitro platforms to faithfully maintain and precisely manipulate stem cell fates is essential to understand the basic mechanisms of stem cell biology,and to translate stem cells into regenerative medicine.Chemical approaches have recently provided a number of small molecules that can be used to control cell selfrenewal,lineage differentiation,reprogramming and regeneration.These chemical modulators have been proven to be versatile tools for probing stem cell biology and manipulating cell fates toward desired outcomes.Ultimately,this strategy is promising to be a new frontier for drug development aimed at endogenous stem cell modulation.

  19. Phytochemical and biological investigation of Begonia heracleifolia.

    Science.gov (United States)

    Frei, B; Heinrich, M; Herrmann, D; Orjala, J E; Schmitt, J; Sticher, O

    1998-05-01

    From the rhizomes of Begonia heracleifolia six known cucurbitacins ( 1- 6) were isolated. Based on spectral data (1D and 2D (1)H-, (13)C-NMR, ESI- and CI-MS) the structures were established as cucurbitacin B ( 1), cucurbitacin D ( 2), 23,24-dihydrocucurbitacin D ( 3), 23,24-dihydrocucurbitacin F ( 4), 2- O-beta-glucopyranosyl-cucurbitacin B ( 5), and 2- O-beta-glucopyranosyl-cucurbitacin D ( 6). Four of them ( 3- 6) were so far not reported as constituents of Begonia spp. Varyingly strong antiproliferative activity towards tumor and immune cells was observed for three compounds ( 1 - 3), due to different structural features.

  20. Building a path in cell biology.

    Science.gov (United States)

    Voeltz, Gia; Cheeseman, Iain

    2012-11-01

    Setting up a new lab is an exciting but challenging prospect. We discuss our experiences in finding a path to tackle some of the key current questions in cell biology and the hurdles that we have encountered along the way.

  1. A chemist building paths to cell biology.

    Science.gov (United States)

    Weibel, Douglas B

    2013-11-01

    Galileo is reported to have stated, "Measure what is measurable and make measurable what is not so." My group's trajectory in cell biology has closely followed this philosophy, although it took some searching to find this path.

  2. Cell Biology of Prokaryotic Organelles

    OpenAIRE

    Murat, Dorothee; Byrne, Meghan; Komeili, Arash

    2010-01-01

    Mounting evidence in recent years has challenged the dogma that prokaryotes are simple and undefined cells devoid of an organized subcellular architecture. In fact, proteins once thought to be the purely eukaryotic inventions, including relatives of actin and tubulin control prokaryotic cell shape, DNA segregation, and cytokinesis. Similarly, compartmentalization, commonly noted as a distinguishing feature of eukaryotic cells, is also prevalent in the prokaryotic world in the form of protein-...

  3. Biological Fuel Cells and Membranes.

    Science.gov (United States)

    Ghassemi, Zahra; Slaughter, Gymama

    2017-01-17

    Biofuel cells have been widely used to generate bioelectricity. Early biofuel cells employ a semi-permeable membrane to separate the anodic and cathodic compartments. The impact of different membrane materials and compositions has also been explored. Some membrane materials are employed strictly as membrane separators, while some have gained significant attention in the immobilization of enzymes or microorganisms within or behind the membrane at the electrode surface. The membrane material affects the transfer rate of the chemical species (e.g., fuel, oxygen molecules, and products) involved in the chemical reaction, which in turn has an impact on the performance of the biofuel cell. For enzymatic biofuel cells, Nafion, modified Nafion, and chitosan membranes have been used widely and continue to hold great promise in the long-term stability of enzymes and microorganisms encapsulated within them. This article provides a review of the most widely used membrane materials in the development of enzymatic and microbial biofuel cells.

  4. Cell biology of prokaryotic organelles.

    Science.gov (United States)

    Murat, Dorothee; Byrne, Meghan; Komeili, Arash

    2010-10-01

    Mounting evidence in recent years has challenged the dogma that prokaryotes are simple and undefined cells devoid of an organized subcellular architecture. In fact, proteins once thought to be the purely eukaryotic inventions, including relatives of actin and tubulin control prokaryotic cell shape, DNA segregation, and cytokinesis. Similarly, compartmentalization, commonly noted as a distinguishing feature of eukaryotic cells, is also prevalent in the prokaryotic world in the form of protein-bounded and lipid-bounded organelles. In this article we highlight some of these prokaryotic organelles and discuss the current knowledge on their ultrastructure and the molecular mechanisms of their biogenesis and maintenance.

  5. Interfacing nanostructures to biological cells

    Science.gov (United States)

    Chen, Xing; Bertozzi, Carolyn R.; Zettl, Alexander K.

    2012-09-04

    Disclosed herein are methods and materials by which nanostructures such as carbon nanotubes, nanorods, etc. are bound to lectins and/or polysaccharides and prepared for administration to cells. Also disclosed are complexes comprising glycosylated nanostructures, which bind selectively to cells expressing glycosylated surface molecules recognized by the lectin. Exemplified is a complex comprising a carbon nanotube functionalized with a lipid-like alkane, linked to a polymer bearing repeated .alpha.-N-acetylgalactosamine sugar groups. This complex is shown to selectively adhere to the surface of living cells, without toxicity. In the exemplified embodiment, adherence is mediated by a multivalent lectin, which binds both to the cells and the .alpha.-N-acetylgalactosamine groups on the nanostructure.

  6. Student-Directed Investigations in Enzymology for Introductory College Biology.

    Science.gov (United States)

    Posner, Herbert B.; Markstein, James A.

    1998-01-01

    Reports on the design and testing of student-directed investigations for use in large enrollment biology courses. Describes a set of experiments that include the preparation and study of the enzyme tyrosinase. (DDR)

  7. Cell Biology: Scaling and the Emergence of Evolutionary Cell Biology

    Science.gov (United States)

    Phillips, Patrick C.; Bowerman, Bruce

    2015-01-01

    A new study investigating the origins of diversity in the structure of the mitotic spindle in nematode embryos, at timescales spanning a few generations to hundreds of millions of years, finds that most features of the spindle evolve via a scaling relationship generated by natural selection acting directly upon embryo size. PMID:25784038

  8. Cell biology: scaling and the emergence of evolutionary cell biology.

    Science.gov (United States)

    Phillips, Patrick C; Bowerman, Bruce

    2015-03-16

    A new study investigating the origins of diversity in the structure of the mitotic spindle in nematode embryos, at timescales spanning a few generations to hundreds of millions of years, finds that most features of the spindle evolve via a scaling relationship generated by natural selection acting directly upon embryo size.

  9. Modeling cell-in-cell structure into its biological significance

    OpenAIRE

    He, M-f; Wang, S.; Wang, Y; Wang, X-N.

    2013-01-01

    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ‘entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  10. An Audiovisual Program in Cell Biology

    Science.gov (United States)

    Fedoroff, Sergey; Opel, William

    1978-01-01

    A subtopic of cell biology, the structure and function of cell membranes, has been developed as a series of seven self-instructional slide-tape units and tested in five medical schools. Organization of advisers, analysis and definition of objectives and content, and development and evaluation of scripts and storyboards are discussed. (Author/LBH)

  11. Spatial Modeling Tools for Cell Biology

    Science.gov (United States)

    2006-10-01

    34 iv Figure 5.1: Computational results for a diffusion problem on planar square thin film............ 36 Figure 5.2... Wisc . Open Microscopy Env. Pre-CoBi Model Lib. CFDRC CoBi Tools CFDRC CoBi Tools Simulation Environment JigCell Tools Figure 4.1: Cell biology

  12. Cell biology: More than skin deep

    Science.gov (United States)

    Fuchs, Elaine

    2015-01-01

    In studying how stem cells make and maintain tissues, nearly every chapter of a cell biology textbook is of interest. The field even allows us to venture where no chapters have yet been written. In studying this basic problem, we are continually bombarded by nature’s surprises and challenges. PMID:26056136

  13. Cell biology experiments conducted in space

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

  14. Cell biology experiments conducted in space

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

  15. Chromatography methods in investigation of lipophilicity of the biological active substances

    OpenAIRE

    Odović Jadranka V.; Trbojević-Stanković Jasna B.

    2009-01-01

    This paper presents the review of the methods used in research of the biological active substances hydrophobicity, a very important property. The biological activity of some substances depends on their pharmacokinetics and pharmacodynamics. These processes depend on the molecule's capability to interact with two different media: aqueous (cells interior) and non-aqueous (cells membrane), or on the molecule lipophilicity. Today, great attention is given to investigation and systematic determina...

  16. Cell biology solves mysteries of reproduction.

    Science.gov (United States)

    Sutovsky, Peter

    2012-09-01

    Reproduction and fertility have been objects of keen inquiry since the dawn of humanity. Medieval anatomists provided the first accurate depictions of the female reproductive system, and early microscopists were fascinated by the magnified sight of sperm cells. Initial successes were achieved in the in vitro fertilization of frogs and the artificial insemination of dogs. Gamete and embryo research was in the cradle of modern cell biology, providing the first evidence of the multi-cellular composition of living beings and pointing out the importance of chromosomes for heredity. In the 20th century, reproductive research paved the way for the study of the cytoskeleton, cell signaling, and the cell cycle. In the last three decades, the advent of reproductive cell biology has brought us human in vitro fertilization, animal cloning, and human and animal embryonic stem cells. It has contributed to the development of transgenesis, proteomics, genomics, and epigenetics. This Special Issue represents a sample of the various areas of reproductive biology, with emphasis on molecular and cell biological aspects. Advances in spermatology, ovarian function, fertilization, and maternal-fetal interactions are discussed within the framework of fertility and diseases such as endometriosis and diabetes.

  17. Measuring cell identity in noisy biological systems

    OpenAIRE

    Kenneth D Birnbaum; Kussell, Edo

    2011-01-01

    Global gene expression measurements are increasingly obtained as a function of cell type, spatial position within a tissue and other biologically meaningful coordinates. Such data should enable quantitative analysis of the cell-type specificity of gene expression, but such analyses can often be confounded by the presence of noise. We introduce a specificity measure Spec that quantifies the information in a gene's complete expression profile regarding any given cell type, and an uncertainty me...

  18. Progeria: translational insights from cell biology.

    Science.gov (United States)

    Gordon, Leslie B; Cao, Kan; Collins, Francis S

    2012-10-01

    Cell biologists love to think outside the box, pursuing many surprising twists and unexpected turns in their quest to unravel the mysteries of how cells work. But can cell biologists think outside the bench? We are certain that they can, and clearly some already do. To encourage more cell biologists to venture into the realm of translational research on a regular basis, we would like to share a handful of the many lessons that we have learned in our effort to develop experimental treatments for Hutchinson-Gilford progeria syndrome (HGPS), an endeavor that many view as a "poster child" for how basic cell biology can be translated to the clinic.

  19. Embryonic stem cells: prospects for developmental biology and cell therapy.

    Science.gov (United States)

    Wobus, Anna M; Boheler, Kenneth R

    2005-04-01

    Stem cells represent natural units of embryonic development and tissue regeneration. Embryonic stem (ES) cells, in particular, possess a nearly unlimited self-renewal capacity and developmental potential to differentiate into virtually any cell type of an organism. Mouse ES cells, which are established as permanent cell lines from early embryos, can be regarded as a versatile biological system that has led to major advances in cell and developmental biology. Human ES cell lines, which have recently been derived, may additionally serve as an unlimited source of cells for regenerative medicine. Before therapeutic applications can be realized, important problems must be resolved. Ethical issues surround the derivation of human ES cells from in vitro fertilized blastocysts. Current techniques for directed differentiation into somatic cell populations remain inefficient and yield heterogeneous cell populations. Transplanted ES cell progeny may not function normally in organs, might retain tumorigenic potential, and could be rejected immunologically. The number of human ES cell lines available for research may also be insufficient to adequately determine their therapeutic potential. Recent molecular and cellular advances with mouse ES cells, however, portend the successful use of these cells in therapeutics. This review therefore focuses both on mouse and human ES cells with respect to in vitro propagation and differentiation as well as their use in basic cell and developmental biology and toxicology and presents prospects for human ES cells in tissue regeneration and transplantation.

  20. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  1. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...... activation through coculture with T cells activated by anti-T-cell receptor or anti-CD3 antibodies suggest that cellular interaction with T cells, independent of antigen presentation or lymphokine secretion, induces or triggers B cells to become responsive to T-derived lymphokines, and that this may...

  2. Recent advances in hematopoietic stem cell biology

    DEFF Research Database (Denmark)

    Bonde, Jesper; Hess, David A; Nolta, Jan A

    2004-01-01

    PURPOSE OF REVIEW: Exciting advances have been made in the field of hematopoietic stem cell biology during the past year. This review summarizes recent progress in the identification, culture, and in vivo tracking of hematopoietic stem cells. RECENT FINDINGS: The roles of Wnt and Notch proteins...... in regulating stem cell renewal in the microenvironment, and how these molecules can be exploited in ex vivo stem cell culture, are reviewed. The importance of identification of stem cells using functional as well as phenotypic markers is discussed. The novel field of nanotechnology is then discussed...... in the context of stem cell tracking in vivo. This review concludes with a section on the unexpected potential of bone marrow-derived stem cells to contribute to the repair of damaged tissues. The contribution of cell fusion to explain the latter phenomenon is discussed. SUMMARY: Because of exciting discoveries...

  3. Nanotechnologies and chemical tools for cell biology

    Science.gov (United States)

    Chen, Xing

    This dissertation describes several nanotechnologies and chemical tools that I have developed to probe living cells. Chapter one gives a brief overview on the current status of biomedical and biotechnological applications of carbon nanotubes (CNTs). In this chapter, strategies for functionalization of CNTs with emphasis on biological applications are reviewed. Representative developments in biosensing, bioimaging, intracellular delivery, and tissue engineering are presented. Recent studies on toxicity of CNTs are also discussed. Chapter two describes the development of a nanoscale cell injector for delivery of cargo to the interior of living cells without physiological harm. A CNT attached to an atomic force microscope tip was functionalized with cargo via a disulfide linker. Penetration of cell membranes with this "nanoneedle", followed by reductive cleavage of the disulfide bonds within the cell's interior, resulted in the release of cargo inside the cells. Chapter three presents a biomimetic functionalization strategy for interfacing CNTs with biological systems. The potential biological applications of CNTs have been limited by their insolubility in aqueous environment and their intrinsic toxicity. We developed a biomimetic surface modification of CNTs using glycosylated polymers designed to mimic natural cell surface mucin glycoproteins interactions. Chapter four further extends the biomimetic strategy for functionalization of CNTs to glycosylated dendrimers. We developed a new class of amphiphilic bifunctional glycodendrimers that comprised carbohydrate units displayed in the periphery and a pyrene tail that bound to SWNT surface via pi-pi interactions. The glycodendrimer-coated CNTs were soluble in water, and noncytotoxic. We also demonstrated that the coated CNTs could interface with biological systems including proteins and cells. Chapter five presents a biosensing application of glycodenderimer-coated CNTs. SWNTN-FETs coated with glycodendrimers were

  4. The biology of cancer stem cells.

    Science.gov (United States)

    Lobo, Neethan A; Shimono, Yohei; Qian, Dalong; Clarke, Michael F

    2007-01-01

    Cancers originally develop from normal cells that gain the ability to proliferate aberrantly and eventually turn malignant. These cancerous cells then grow clonally into tumors and eventually have the potential to metastasize. A central question in cancer biology is, which cells can be transformed to form tumors? Recent studies elucidated the presence of cancer stem cells that have the exclusive ability to regenerate tumors. These cancer stem cells share many characteristics with normal stem cells, including self-renewal and differentiation. With the growing evidence that cancer stem cells exist in a wide array of tumors, it is becoming increasingly important to understand the molecular mechanisms that regulate self-renewal and differentiation because corruption of genes involved in these pathways likely participates in tumor growth. This new paradigm of oncogenesis has been validated in a growing list of tumors. Studies of normal and cancer stem cells from the same tissue have shed light on the ontogeny of tumors. That signaling pathways such as Bmi1 and Wnt have similar effects in normal and cancer stem cell self-renewal suggests that common molecular pathways regulate both populations. Understanding the biology of cancer stem cells will contribute to the identification of molecular targets important for future therapies.

  5. CMOS based sensor for dielectric spectroscopy of biological cell suspension

    Science.gov (United States)

    Guha, S.; Schmalz, K.; Meliani, C.; Wenger, Ch

    2013-04-01

    In this work we investigate the use of microwave frequency range to measure the concentration of cells in a biological cell suspension. A theoretical model is discussed and the advantage of high frequency, which is to avoid dispersion mechanisms due to the cell parameters at lower frequencies (for example membrane capacitance), has been described. Interdigitated capacitor (IDC) has been proposed as the sensor for analysing the concentration of a cell species in the suspension. The read-out circuit is a VCO using the IDC and a pair of inductors as resonator. The capacitance of the IDC which is the function of the permittivity of the biological cell suspension determines the resonant frequency of the LC tank oscillator. Thus the concentration of cells in a solution, affecting its permittivity, is read out as the frequency of the oscillator.

  6. Textbook Errors & Misconceptions in Biology: Cell Metabolism.

    Science.gov (United States)

    Storey, Richard D.

    1991-01-01

    The idea that errors and misconceptions in biology textbooks are often slow to be discovered and corrected is discussed. Selected errors, misconceptions, and topics of confusion about cell metabolism are described. Fermentation, respiration, Krebs cycle, pentose phosphate pathway, uniformity of catabolism, and metabolic pathways as models are…

  7. Textbook Errors & Misconceptions in Biology: Cell Metabolism.

    Science.gov (United States)

    Storey, Richard D.

    1991-01-01

    The idea that errors and misconceptions in biology textbooks are often slow to be discovered and corrected is discussed. Selected errors, misconceptions, and topics of confusion about cell metabolism are described. Fermentation, respiration, Krebs cycle, pentose phosphate pathway, uniformity of catabolism, and metabolic pathways as models are…

  8. Cell Science and Cell Biology Research at MSFC: Summary

    Science.gov (United States)

    2003-01-01

    The common theme of these research programs is that they investigate regulation of gene expression in cells, and ultimately gene expression is controlled by the macromolecular interactions between regulatory proteins and DNA. The NASA Critical Path Roadmap identifies Muscle Alterations and Atrophy and Radiation Effects as Very Serious Risks and Severe Risks, respectively, in long term space flights. The specific problem addressed by Dr. Young's research ("Skeletal Muscle Atrophy and Muscle Cell Signaling") is that skeletal muscle loss in space cannot be prevented by vigorous exercise. Aerobic skeletal muscles (i.e., red muscles) undergo the most extensive atrophy during long-term space flight. Of the many different potential avenues for preventing muscle atrophy, Dr. Young has chosen to study the beta-adrenergic receptor (betaAR) pathway. The reason for this choice is that a family of compounds called betaAR agonists will preferentially cause an increase in muscle mass of aerobic muscles (i.e., red muscle) in animals, potentially providing a specific pharmacological solution to muscle loss in microgravity. In addition, muscle atrophy is a widespread medical problem in neuromuscular diseases, spinal cord injury, lack of exercise, aging, and any disease requiring prolonged bedridden status. Skeletal muscle cells in cell culture are utilized as a model system to study this problem. Dr. Richmond's research ("Radiation & Cancer Biology of Mammary Cells in Culture") is directed toward developing a laboratory model for use in risk assessment of cancer caused by space radiation. This research is unique because a human model will be developed utilizing human mammary cells that are highly susceptible to tumor development. This approach is preferential over using animal cells because of problems in comparing radiation-induced cancers between humans and animals.

  9. Cell Science and Cell Biology Research at MSFC: Summary

    Science.gov (United States)

    2003-01-01

    The common theme of these research programs is that they investigate regulation of gene expression in cells, and ultimately gene expression is controlled by the macromolecular interactions between regulatory proteins and DNA. The NASA Critical Path Roadmap identifies Muscle Alterations and Atrophy and Radiation Effects as Very Serious Risks and Severe Risks, respectively, in long term space flights. The specific problem addressed by Dr. Young's research ("Skeletal Muscle Atrophy and Muscle Cell Signaling") is that skeletal muscle loss in space cannot be prevented by vigorous exercise. Aerobic skeletal muscles (i.e., red muscles) undergo the most extensive atrophy during long-term space flight. Of the many different potential avenues for preventing muscle atrophy, Dr. Young has chosen to study the beta-adrenergic receptor (betaAR) pathway. The reason for this choice is that a family of compounds called betaAR agonists will preferentially cause an increase in muscle mass of aerobic muscles (i.e., red muscle) in animals, potentially providing a specific pharmacological solution to muscle loss in microgravity. In addition, muscle atrophy is a widespread medical problem in neuromuscular diseases, spinal cord injury, lack of exercise, aging, and any disease requiring prolonged bedridden status. Skeletal muscle cells in cell culture are utilized as a model system to study this problem. Dr. Richmond's research ("Radiation & Cancer Biology of Mammary Cells in Culture") is directed toward developing a laboratory model for use in risk assessment of cancer caused by space radiation. This research is unique because a human model will be developed utilizing human mammary cells that are highly susceptible to tumor development. This approach is preferential over using animal cells because of problems in comparing radiation-induced cancers between humans and animals.

  10. An electrostatic model for biological cell division

    CERN Document Server

    Faraggi, Eshel

    2010-01-01

    Probably the most fundamental processes for biological systems is their ability to create themselves through the use of cell division and cell differentiation. In this work a simple physical model is proposed for biological cell division. The model consists of a positive ionic gradient across the cell membrane, and concentration of charge at the nodes of the spindle and on the chromosomes. A simple calculation, based on Coulomb's Law, shows that under such circumstances a chromosome will tend to break up to its constituent chromatids and that the chromatids will be separated by a distance that is an order of thirty percent of the distance between the spindle nodes. Further repulsion between the nodes will tend to stretch the cell and eventually break the cell membrane between the separated chromatids, leading to cell division. The importance of this work is in continuing the understanding of the electromagnetic basis of cell division and providing it with an analytical model. A central implication of this and...

  11. Biological impact of human embryonic stem cells.

    Science.gov (United States)

    Martín, Miguel; Menéndez, Pablo

    2012-01-01

    Research on human embryonic stem cells (hESCs) and induced pluripotent (iPS) stem cells is currently a field of great potential in biomedicine. These cells represent a highly valuable tool for developmental biology studies, disease models, and drug screening and toxicity. The ultimate goal of hESCs and iPS cell research is the treatment of diseases or disorders for which there is currently no treatment or existing therapies are only partially effective. Despite the disproportionate short-term hopes generated, which are putting too much pressure on scientists, the international scientific community is making rapid progress in understanding hESCs and iPS cells. Nonetheless, great efforts have to be made to provide an answer to still quite basic questions concerning their biology. Moreover, translation to clinical applications in cell replacement therapy requires prior solution to ethical barriers. The recent development of iPS cells has provided a strong alternative to overcome ethical issues concerning hESCs. However, an in-depth characterization of their genetic and epigenetic features, as well as their differentiation potential still remains to be undertaken. This chapter will describe, precisely, what the critical issues are, where scientific and ethical barriers stand, and how we are to overcome them. Only then, we shall finally discover whether hESCs and iPS cells will allow building reproducible disease models, and whether they really are a safe tool, with great potential for regenerative medicine.

  12. Ion channels regulating mast cell biology.

    Science.gov (United States)

    Ashmole, I; Bradding, P

    2013-05-01

    Mast cells play a central role in the pathophysiology of asthma and related allergic conditions. Mast cell activation leads to the degranulation of preformed mediators such as histamine and the secretion of newly synthesised proinflammatory mediators such as leukotrienes and cytokines. Excess release of these mediators contributes to allergic disease states. An influx of extracellular Ca2+ is essential for mast cell mediator release. From the Ca2+ channels that mediate this influx, to the K+ , Cl- and transient receptor potential channels that set the cell membrane potential and regulate Ca2+ influx, ion channels play a critical role in mast cell biology. In this review we provide an overview of our current knowledge of ion channel expression and function in mast cells with an emphasis on how channels interact to regulate Ca2+ signalling.

  13. Electron Tomography in Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This review focuses on the contribution of electron tomography-based techniques to our understanding of cellular processes in plant cells. Electron microscopy techniques have evolved to provide better three-dimensional resolution and improved preservation of the subcellular components. In particular, the combination of cryofixation/freeze substitution and electron tomography have allowed plant cell biologists to image organelles and macromolecular complexes in their native cellular context with unprecedented three-dimensional resolution (4-7 nm). Until now, electron tomography has been applied in plant cell biology for the study of cytokinesis, Golgi structure and trafficking, formation of plant endosome/prevacuolar compartments, and organization of photosynthetic membranes. We discuss in this review the new insights that these tomographic studies have brought to the plant biology field.

  14. Biological Influence of Deuterium on Procariotic and Eukaryotic Cells

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2014-03-01

    Full Text Available Biologic influence of deuterium (D on cells of various taxonomic groups of prokaryotic and eukaryotic microorganisms realizing methylotrophic, chemoheterotrophic, photo-organotrophic, and photosynthetic ways of assimilation of carbon substrates are investigated at growth on media with heavy water (D2О. The method of step by step adaptation technique of cells to D2О was developed, consisting in plating of cells on 2 % agarose nutrient media containing increasing gradient of concentration of D2О (from 0 up to 98 % D2O and the subsequent selection of stable to D2O cells. In the result of that technique were obtained adapted to maximum concentration of D2O cells, biological material of which instead of hydrogen contained deuterium with levels of enrichment 92–97,5 at.% D.

  15. Progeria: Translational insights from cell biology

    Science.gov (United States)

    Gordon, Leslie B.; Cao, Kan

    2012-01-01

    Cell biologists love to think outside the box, pursuing many surprising twists and unexpected turns in their quest to unravel the mysteries of how cells work. But can cell biologists think outside the bench? We are certain that they can, and clearly some already do. To encourage more cell biologists to venture into the realm of translational research on a regular basis, we would like to share a handful of the many lessons that we have learned in our effort to develop experimental treatments for Hutchinson-Gilford progeria syndrome (HGPS), an endeavor that many view as a “poster child” for how basic cell biology can be translated to the clinic. PMID:23027899

  16. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...... includes multipoint intermolecular interactions that probably involve aggregation of both polymorphic and monomorphic T cell surface molecules. Such aggregations have been shown in vitro to markedly enhance and, in some cases, induce T cell activation. The production of T-derived lymphokines that have been...... implicated in B cell activation is dependent on the T cell receptor for antigen and its associated CD3 signalling complex. T-dependent help for B cell activation is therefore similarly MHC-restricted and involves T-B intercellular interaction. Recent reports that describe antigen-independent B cell...

  17. The biology of innate lymphoid cells.

    Science.gov (United States)

    Artis, David; Spits, Hergen

    2015-01-15

    The innate immune system is composed of a diverse array of evolutionarily ancient haematopoietic cell types, including dendritic cells, monocytes, macrophages and granulocytes. These cell populations collaborate with each other, with the adaptive immune system and with non-haematopoietic cells to promote immunity, inflammation and tissue repair. Innate lymphoid cells are the most recently identified constituents of the innate immune system and have been the focus of intense investigation over the past five years. We summarize the studies that formally identified innate lymphoid cells and highlight their emerging roles in controlling tissue homeostasis in the context of infection, chronic inflammation, metabolic disease and cancer.

  18. Cells — An Open Access Journal of Cell Biology

    Directory of Open Access Journals (Sweden)

    Shu-Kun Lin

    2011-01-01

    Full Text Available To expand the open access publishing project of our newly founded company MDPI [1,2] based in Basel, Switzerland, we are in the process of launching new journals. Based on our success in running journals that represent key areas in science and technology, such as Molecules [3], Sensors [4], Energies [5], Viruses [6], Pharmaceuticals [7], Cancers [8] and Toxins [9], we are launching a new journal entitled Cells. It is an open access journal combining cell biology, molecular biology and biophysics, toward an understanding of cell structure, function and interactions. [...

  19. Femtosecond fabricated surfaces for cell biology

    Science.gov (United States)

    Day, Daniel; Gu, Min

    2010-08-01

    Microfabrication using femtosecond pulse lasers is enabling access to a range of structures, surfaces and materials that was not previously available for scientific and engineering applications. The ability to produce micrometre sized features directly in polymer and metal substrates is demonstrated with applications in cell biology. The size, shape and aspect ratio of the etched features can be precisely controlled through the manipulation of the fluence of the laser etching process with respect to the properties of the target material. Femtosecond laser etching of poly(methyl methacrylate) and aluminium substrates has enabled the production of micrometre resolution moulds that can be accurately replicated using soft lithography. The moulded surfaces are used in the imaging of T cells and demonstrate the improved ability to observe biological events over time periods greater than 10 h. These results indicate the great potential femtosecond pulse lasers may have in the future manufacturing of microstructured surfaces and devices.

  20. Dictyostelium discoideum: Molecular approaches to cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Spudich, J.A.

    1987-01-01

    The central point of this book is to present Dictyostelium as a valuable eukaryotic organism for those interested in molecular studies that require a combined biochemical, structural, and genetic approach. The book is not meant to be a comprehensive compilation of all methods involving Dictyostelium, but instead is a selective set of chapters that demonstrates the utility of the organism for molecular approaches to interesting cell biological problems.

  1. The cell biology of fat expansion.

    Science.gov (United States)

    Rutkowski, Joseph M; Stern, Jennifer H; Scherer, Philipp E

    2015-03-02

    Adipose tissue is a complex, multicellular organ that profoundly influences the function of nearly all other organ systems through its diverse metabolite and adipokine secretome. Adipocytes are the primary cell type of adipose tissue and play a key role in maintaining energy homeostasis. The efficiency with which adipose tissue responds to whole-body energetic demands reflects the ability of adipocytes to adapt to an altered nutrient environment, and has profound systemic implications. Deciphering adipocyte cell biology is an important component of understanding how the aberrant physiology of expanding adipose tissue contributes to the metabolic dysregulation associated with obesity. © 2015 Rutkowski et al.

  2. The cell biology of fat expansion

    Science.gov (United States)

    Rutkowski, Joseph M.; Stern, Jennifer H.

    2015-01-01

    Adipose tissue is a complex, multicellular organ that profoundly influences the function of nearly all other organ systems through its diverse metabolite and adipokine secretome. Adipocytes are the primary cell type of adipose tissue and play a key role in maintaining energy homeostasis. The efficiency with which adipose tissue responds to whole-body energetic demands reflects the ability of adipocytes to adapt to an altered nutrient environment, and has profound systemic implications. Deciphering adipocyte cell biology is an important component of understanding how the aberrant physiology of expanding adipose tissue contributes to the metabolic dysregulation associated with obesity. PMID:25733711

  3. Biological cell manipulation by magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Frederick Gertz

    2016-02-01

    Full Text Available We report a manipulation of biological cells (erythrocytes by magnetite (Fe3O4 nanoparticles in the presence of a magnetic field. The experiment was accomplished on the top of a micro-electromagnet consisting of two magnetic field generating contours. An electric current flowing through the contour(s produces a non-uniform magnetic field, which is about 1.4 mT/μm in strength at 100 mA current in the vicinity of the current-carrying wire. In responses to the magnetic field, magnetic nanoparticles move towards the systems energy minima. In turn, magnetic nanoparticles drag biological cells in the same direction. We present experimental data showing cell manipulation through the control of electric current. This technique allows us to capture and move cells located in the vicinity (10-20 microns of the current-carrying wires. One of the most interesting results shows a periodic motion of erythrocytes between the two conducting contours, whose frequency is controlled by an electric circuit. The obtained results demonstrate the feasibility of non-destructive cell manipulation by magnetic nanoparticles with micrometer-scale precision.

  4. Autophagic regulation of smooth muscle cell biology

    Science.gov (United States)

    Salabei, Joshua K.; Hill, Bradford G.

    2014-01-01

    Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (patho)physiology. PMID:25544597

  5. Autophagic regulation of smooth muscle cell biology

    Directory of Open Access Journals (Sweden)

    Joshua K. Salabei

    2015-04-01

    Full Text Available Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (pathophysiology.

  6. Micro and nano-platforms for biological cell analysis

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Castillo, Jaime; Moresco, Jacob Lange;

    2011-01-01

    In this paper some technological platforms developed for biological cell analysis will be presented and compared to existing systems. In brief, we present a novel micro cell culture chamber based on diffusion feeding of cells, into which cells can be introduced and extracted after culturing using...... normal pipettes, thus making it readily usable for clinical laboratories. To enhance the functionality of such a chamber we have been investigating the use of active or passive 3D surface modifications. Active modifications involve miniature electrodes able to record electrical or electrochemical signals...... from the cells, while passive modifications involve the presence of a peptide nanotube based scaffold for the cell culturing that mimics the in vivo environment. Two applications involving fluorescent in situ hybridization (FISH) analysis and cancer cell sorting are presented, as examples of further...

  7. Celebrating Plant Cells: A Special Issue on Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ A special issue on plant cell biology is long overdue for JIPB! In the last two decades or so, the plant biology community has been thrilled by explosive discoveries regarding the molecular and genetic basis of plant growth, development, and responses to the environment, largely owing to recent maturation of model systems like Arabidopsis thaliana and the rice Oryza sativa, as well as the rapid development of high throughput technologies associated with genomics and proteomics.

  8. Stem cell genome-to-systems biology.

    Science.gov (United States)

    Chia, Na-Yu; Ng, Huck-Hui

    2012-01-01

    Stem cells are capable of extended proliferation and concomitantly differentiating into a plethora of specialized cell types that render them apropos for their usage as a form of regenerative medicine for cell replacement therapies. The molecular processes that underlie the ability for stem cells to self-renew and differentiate have been intriguing, and elucidating the intricacies within the genome is pertinent to enhance our understanding of stem cells. Systems biology is emerging as a crucial field in the study of the sophisticated nature of stem cells, through the adoption of multidisciplinary approaches which couple high-throughput experimental techniques with computational and mathematical analysis. This allows for the determination of the molecular constituents that govern stem cell characteristics and conjointly with functional validations via genetic perturbation and protein location binding analysis necessitate the construction of the complex transcriptional regulatory network. With the elucidation of protein-protein interaction, protein-DNA regulation, microRNA involvement as well as the epigenetic modifications, it is possible to comprehend the defining features of stem cells at the system level. Copyright © 2011 John Wiley & Sons, Inc.

  9. Stem cells - biological update and cell therapy progress.

    Science.gov (United States)

    Girlovanu, Mihai; Susman, Sergiu; Soritau, Olga; Rus-Ciuca, Dan; Melincovici, Carmen; Constantin, Anne-Marie; Mihu, Carmen Mihaela

    2015-01-01

    In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods to prevent teratoma formation or the ethical and religious issues regarding especially the embryonic stem cell research. The direct differentiation of stem cells into specialized cells: cardiac myocytes, neural cells, pancreatic islets cells, may represent an option in treating incurable diseases such as: neurodegenerative diseases, type I diabetes, hematologic or cardiac diseases. Nevertheless, stem cell-based therapies, based on stem cell transplantation, remain mainly at the experimental stages and their major limitation is the development of teratoma and cancer after transplantation. The induced pluripotent stem cells (hiPSCs) represent a prime candidate for future cell therapy research because of their significant self-renewal and differentiation potential and the lack of ethical issues. This article presents an overview of the biological advances in the study of stem cells and the current progress made in the field of regenerative medicine.

  10. Analysis of undergraduate cell biology contents in Brazilian public universities.

    Science.gov (United States)

    Mermelstein, Claudia; Costa, Manoel Luis

    2017-04-01

    The enormous amount of information available in cell biology has created a challenge in selecting the core concepts we should be teaching our undergraduates. One way to define a set of essential core ideas in cell biology is to analyze what a specific cell biology community is teaching their students. Our main objective was to analyze the cell biology content currently being taught in Brazilian universities. We collected the syllabi of cell biology courses from public universities in Brazil and analyzed the frequency of cell biology topics in each course. We also compared the Brazilian data with the contents of a major cell biology textbook. Our analysis showed that while some cell biology topics such as plasma membrane and cytoskeleton was present in ∼100% of the Brazilian curricula analyzed others such as cell signaling and cell differentiation were present in only ∼35%. The average cell biology content taught in the Brazilian universities is quite different from what is presented in the textbook. We discuss several possible explanations for these observations. We also suggest a list with essential cell biology topics for any biological or biomedical undergraduate course. The comparative discussion of cell biology topics presented here could be valuable in other educational contexts.

  11. Cell biology of the Koji mold Aspergillus oryzae.

    Science.gov (United States)

    Kitamoto, Katsuhiko

    2015-01-01

    Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

  12. Chromatography methods in investigation of lipophilicity of the biological active substances

    Directory of Open Access Journals (Sweden)

    Odović Jadranka V.

    2009-01-01

    Full Text Available This paper presents the review of the methods used in research of the biological active substances hydrophobicity, a very important property. The biological activity of some substances depends on their pharmacokinetics and pharmacodynamics. These processes depend on the molecule's capability to interact with two different media: aqueous (cells interior and non-aqueous (cells membrane, or on the molecule lipophilicity. Today, great attention is given to investigation and systematic determination of drugs lipophilicity. In these researches chromatography methods have an important role.

  13. Cell biology: at the center of modern biomedicine.

    Science.gov (United States)

    Budde, Priya Prakash; Williams, Elizabeth H; Misteli, Tom

    2012-10-01

    How does basic cell biology contribute to biomedicine? A new series of Features in JCB provides a cross section of compelling examples of how basic cell biology findings can lead to therapeutics. These articles highlight the fruitful, essential, and increasingly prominent bridge that exists between cell biology and the clinic.

  14. Systems biology approaches to understanding stem cell fate choice.

    Science.gov (United States)

    Peltier, J; Schaffer, D V

    2010-01-01

    Stem cells have the capability to self-renew and maintain their undifferentiated state or to differentiate into one or more specialised cell types. Stem cell expansion and manipulation ex vivo is a promising approach for engineering cell replacement therapies, and endogenous stem cells represent potential drugable targets for tissue repair. Before we can harness stem cells' therapeutic potential, we must first understand the intracellular mechanisms controlling their fate choices. These mechanisms involve complex signal transduction and gene regulation networks that feature, for example, intricate feed-forward loops, feedback loops and cross-talk between multiple signalling pathways. Systems biology applies computational and experimental approaches to investigate the emergent behaviour of collections of molecules and strives to explain how these numerous components interact to regulate molecular, cellular and organismal behaviour. Here we review systems biology, and in particular computational, efforts to understand the intracellular mechanisms of stem cell fate choice. We first discuss deterministic and stochastic models that synthesise molecular knowledge into mathematical formalism, enable simulation of important system behaviours and stimulate further experimentation. In addition, statistical analyses such as Bayesian networks and principal components analysis (PCA)/partial least squares (PLS) regression can distill large datasets into more readily managed networks and principal components that provide insights into the critical aspects and components of regulatory networks. Collectively, integrating modelling with experimentation has strong potential for enabling a deeper understanding of stem cell fate choice and thereby aiding the development of therapies to harness stem cells' therapeutic potential.

  15. The cell biology of HIV-1 and other retroviruses

    Directory of Open Access Journals (Sweden)

    Mouland Andrew J

    2006-11-01

    Full Text Available Abstract In recognition of the growing influence of cell biology in retrovirus research, we recently organized a Summer conference sponsored by the American Society for Cell Biology (ASCB on the Cell Biology of HIV-1 and other Retroviruses (July 20–23, 2006, Emory University, Atlanta, Georgia. The meeting brought together a number of leading investigators interested in the interplay between cell biology and retrovirology with an emphasis on presentation of new and unpublished data. The conference was arranged from early to late events in the virus replication cycle, with sessions on viral fusion, entry, and transmission; post-entry restrictions to retroviral infection; nuclear import and integration; gene expression/regulation of retroviral Gag and genomic RNA; and assembly/release. In this review, we will attempt to touch briefly on some of the highlights of the conference, and will emphasize themes and trends that emerged at the meeting. Meeting report The conference began with a keynote address from W. Sundquist on the biochemistry of HIV-1 budding. This presentation will be described in the section on Assembly and Release of Retroviruses.

  16. Systems Biology for Organotypic Cell Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Grego, Sonia [RTI International, Research Triangle Park, NC (United States); Dougherty, Edward R. [Texas A & M Univ., College Station, TX (United States); Alexander, Francis J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Auerbach, Scott S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Berridge, Brian R. [GlaxoSmithKline, Research Triangle Park, NC (United States); Bittner, Michael L. [Translational Genomics Research Inst., Phoenix, AZ (United States); Casey, Warren [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Cooley, Philip C. [RTI International, Research Triangle Park, NC (United States); Dash, Ajit [HemoShear Therapeutics, Charlottesville, VA (United States); Ferguson, Stephen S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Fennell, Timothy R. [RTI International, Research Triangle Park, NC (United States); Hawkins, Brian T. [RTI International, Research Triangle Park, NC (United States); Hickey, Anthony J. [RTI International, Research Triangle Park, NC (United States); Kleensang, Andre [Johns Hopkins Univ., Baltimore, MD (United States). Center for Alternatives to Animal Testing; Liebman, Michael N. [IPQ Analytics, Kennett Square, PA (United States); Martin, Florian [Phillip Morris International, Neuchatel (Switzerland); Maull, Elizabeth A. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Paragas, Jason [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Qiao, Guilin [Defense Threat Reduction Agency, Ft. Belvoir, VA (United States); Ramaiahgari, Sreenivasa [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Sumner, Susan J. [RTI International, Research Triangle Park, NC (United States); Yoon, Miyoung [The Hamner Inst. for Health Sciences, Research Triangle Park, NC (United States); ScitoVation, Research Triangle Park, NC (United States)

    2016-08-04

    Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomic data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data. This consensus report summarizes the discussions held.

  17. Extending the knowledge in histochemistry and cell biology.

    Science.gov (United States)

    Heupel, Wolfgang-Moritz; Drenckhahn, Detlev

    2010-01-01

    Central to modern Histochemistry and Cell Biology stands the need for visualization of cellular and molecular processes. In the past several years, a variety of techniques has been achieved bridging traditional light microscopy, fluorescence microscopy and electron microscopy with powerful software-based post-processing and computer modeling. Researchers now have various tools available to investigate problems of interest from bird's- up to worm's-eye of view, focusing on tissues, cells, proteins or finally single molecules. Applications of new approaches in combination with well-established traditional techniques of mRNA, DNA or protein analysis have led to enlightening and prudent studies which have paved the way toward a better understanding of not only physiological but also pathological processes in the field of cell biology. This review is intended to summarize articles standing for the progress made in "histo-biochemical" techniques and their manifold applications.

  18. Biological characteristics of cell lines of human dental alveolus

    Institute of Scientific and Technical Information of China (English)

    陈世璋; 黄靖香; 孙明学; 赵斌

    2003-01-01

    Objective To investigate the biological characteristics of cell lines of healthy and diseased human dental alveoli. Methods Primary cell lines from either healthy or diseased human dental alveoli were obtained. Two cell lines, H-258 and H-171 derived from healthy and diseased human tissues respectively, were selected for morphological study and research on their growth and aging, using cell counting, and histochemical and immunohistochemical staining. Results Primary cell lines were successfully established from innormal dental alveoli. After freezing and thawing for three times, cell growth was continued and no morphological alterations were observed. The doubling time was 53.4 hours and mean division index (MDI) was 4‰. Cells were kept normal after twenty generations with no obvious reduction of doubling time and MDI. Of twenty-six primary cell lines derived from healthy human dental alveoli, only three cell lines achieved generation. After freezing and thawing for twice, cultured cells were still alive at a decreased growth speed, with doubling time of 85.9 hours and MDI of 3‰. Both cell lines, H-171 and H-258, shared the characteristics of osteoblast. Conclusions Primary cell lines of diseased human dental alveoli show greater growth potential. All cell lines of dental alveoli share characteristics of osteoblast. The technique we developed may be put into practice for the treatment of abnormal dental alveoli.

  19. Biophysical mechanisms complementing "classical" cell biology.

    Science.gov (United States)

    Funk, Richard H W

    2018-01-01

    This overview addresses phenomena in cell- and molecular biology which are puzzling by their fast and highly coordinated way of organization. Generally, it appears that informative processes probably involved are more on the biophysical than on the classical biochemical side. The coordination problem is explained within the first part of the review by the topic of endogenous electrical phenomena. These are found e.g. in fast tissue organization and reorganization processes like development, wound healing and regeneration. Here, coupling into classical biochemical signaling and reactions can be shown by modern microscopy, electronics and bioinformatics. Further, one can follow the triggered reactions seamlessly via molecular biology till into genetics. Direct observation of intracellular electric processes is very difficult because of e.g. shielding through the cell membrane and damping by other structures. Therefore, we have to rely on photonic and photon - phonon coupling phenomena like molecular vibrations, which are addressed within the second part. Molecules normally possess different charge moieties and thus small electromagnetic (EMF) patterns arise during molecular vibration. These patterns can now be measured best within the optical part of the spectrum - much less in the lower terahertz till kHz and lower Hz part (third part of this review). Finally, EMFs facilitate quantum informative processes in coherent domains of molecular, charge and electron spin motion. This helps to coordinate such manifold and intertwined processes going on within cells, tissues and organs (part 4). Because the phenomena described in part 3 and 4 of the review still await really hard proofs we need concerted efforts and a combination of biophysics, molecular biology and informatics to unravel the described mysteries in "physics of life".

  20. Micro and nanoplatforms for biological cell analysis

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Castillo, Jaime; Moresco, Jacob Lange

    2010-01-01

    In this paper some of the technological platforms developed in our group for biological cell analysis will be highlighted. The paper first presents a short introduction pinpointing the advantages of using micro and nano technology in cellular studies. The issues of requiring transient analysis...... studies mimicking the in vivo situation is presented and an example of surface modification for cellular growth is described. Then novel electronic sensor platforms are discussed and an example of a nanosensor with electronic readout is given utilizing both micro- and nanotechnology. Finally an example...

  1. Cell biology and EMF safety standards.

    Science.gov (United States)

    Blank, Martin

    2015-01-01

    Living cells react defensively and start to synthesize stress proteins when exposed to potentially harmful stimuli. Electromagnetic fields (EMF) are among the many different environmental stimuli that initiate stress protein synthesis. Although there is greater energy transfer and heating due to EMF at higher frequencies, there is no greater stress response. The cellular stress response is far more sensitive to EMF than to an increase in temperature. It should be obvious that an EMF safety standard should be based on the more sensitive, natural biological response.

  2. Heart-on-a-chip based on stem cell biology.

    Science.gov (United States)

    Jastrzebska, Elzbieta; Tomecka, Ewelina; Jesion, Iwona

    2016-01-15

    Heart diseases are one of the main causes of death around the world. The great challenge for scientists is to develop new therapeutic methods for these types of ailments. Stem cells (SCs) therapy could be one of a promising technique used for renewal of cardiac cells and treatment of heart diseases. Conventional in vitro techniques utilized for investigation of heart regeneration do not mimic natural cardiac physiology. Lab-on-a-chip systems may be the solution which could allow the creation of a heart muscle model, enabling the growth of cardiac cells in conditions similar to in vivo conditions. Microsystems can be also used for differentiation of stem cells into heart cells, successfully. It will help better understand of proliferation and regeneration ability of these cells. In this review, we present Heart-on-a-chip systems based on cardiac cell culture and stem cell biology. This review begins with the description of the physiological environment and the functions of the heart. Next, we shortly described conventional techniques of stem cells differentiation into the cardiac cells. This review is mostly focused on describing Lab-on-a-chip systems for cardiac tissue engineering. Therefore, in the next part of this article, the microsystems for both cardiac cell culture and SCs differentiation into cardiac cells are described. The section about SCs differentiation into the heart cells is divided in sections describing biochemical, physical and mechanical stimulations. Finally, we outline present challenges and future research concerning Heart-on-a-chip based on stem cell biology. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Single Cell Analysis: From Technology to Biology and Medicine.

    Science.gov (United States)

    Pan, Xinghua

    2014-01-01

    Single-cell analysis heralds a new era that allows "omics" analysis, notably genomics, transcriptomics, epigenomics and proteomics at the single-cell level. It enables the identification of the minor subpopulations that may play a critical role in a biological process of a population of cells, which conventionally are regarded as homogeneous. It provides an ultra-sensitive tool to clarify specific molecular mechanisms and pathways and reveal the nature of cell heterogeneity. It also facilitates the clinical investigation of patients when a very low quantity or a single cell is available for analysis, such as noninvasive prenatal diagnosis and cancer screening, and genetic evaluation for in vitro fertilization. Within a few short years, single-cell analysis, especially whole genomic sequencing and transcriptomic sequencing, is becoming robust and broadly accessible, although not yet a routine practice. Here, with single cell RNA-seq emphasized, an overview of the discipline, progresses, and prospects of single-cell analysis and its applications in biology and medicine are given with a series of logic and theoretical considerations.

  4. Designer nanoparticle: nanobiotechnology tool for cell biology

    Science.gov (United States)

    Thimiri Govinda Raj, Deepak B.; Khan, Niamat Ali

    2016-09-01

    This article discusses the use of nanotechnology for subcellular compartment isolation and its application towards subcellular omics. This technology review significantly contributes to our understanding on use of nanotechnology for subcellular systems biology. Here we elaborate nanobiotechnology approach of using superparamagnetic nanoparticles (SPMNPs) optimized with different surface coatings for subcellular organelle isolation. Using pulse-chase approach, we review that SPMNPs interacted differently with the cell depending on its surface functionalization. The article focuses on the use of functionalized-SPMNPs as a nanobiotechnology tool to isolate high quality (both purity and yield) plasma membranes and endosomes or lysosomes. Such nanobiotechnology tool can be applied in generating subcellular compartment inventories. As a future perspective, this strategy could be applied in areas such as immunology, cancer and stem cell research.

  5. Can molecular cell biology explain chromosome motions?

    Directory of Open Access Journals (Sweden)

    Gagliardi L

    2011-05-01

    Full Text Available Abstract Background Mitotic chromosome motions have recently been correlated with electrostatic forces, but a lingering "molecular cell biology" paradigm persists, proposing binding and release proteins or molecular geometries for force generation. Results Pole-facing kinetochore plates manifest positive charges and interact with negatively charged microtubule ends providing the motive force for poleward chromosome motions by classical electrostatics. This conceptual scheme explains dynamic tracking/coupling of kinetochores to microtubules and the simultaneous depolymerization of kinetochore microtubules as poleward force is generated. Conclusion We question here why cells would prefer complex molecular mechanisms to move chromosomes when direct electrostatic interactions between known bound charge distributions can accomplish the same task much more simply.

  6. Isolation and biological characterization of chicken amnion epithelial cells

    Directory of Open Access Journals (Sweden)

    Y. Gao

    2012-08-01

    Full Text Available Amniotic epithelial cells (AECs express Oct4, Nanog and Sox-2, which are necessary for maintaining the undifferentiated state of pluripotent stem cells. AECs additionally express CK19, which is a specific marker of epithelial cells, both in vivo and in vitro. In this research, we investigated the biological characteristics and potential for cell therapy of AECs from 6-day-old chicken embryos. We induced the AECs to differentiate into pancreatic islet-like cells (endoderm, adipocytes and osteoblasts (mesoderm and neural-like cells (ectoderm, and used immunofluorescence and RT-PCR to detect the expression of AECs specific markers. To assess the differentiation capacity of AECs, passage 3 cells were induced to differentiate into adipocytes, osteoblasts, pancreatic islet-like cells and neural-like cells. The AEC markers, Oct4, Nanog, Sox-2 and CK19, were all positively expressed. Cloning efficiency decreased with increasing passage number. Passage 3 AECs were successfully induced to differentiate into pancreatic islet-like cells, osteoblasts, adipocytes, and neural-like cells. These results suggested that AECs isolated from chicken embryos exhibited the characteristics of the multipotent stem cells. AECs may therefore be ideal candidates for cellular transplantation therapy and tissue engineering.

  7. Cell-free synthetic biology: thinking outside the cell.

    Science.gov (United States)

    Hodgman, C Eric; Jewett, Michael C

    2012-05-01

    Cell-free synthetic biology is emerging as a powerful approach aimed to understand, harness, and expand the capabilities of natural biological systems without using intact cells. Cell-free systems bypass cell walls and remove genetic regulation to enable direct access to the inner workings of the cell. The unprecedented level of control and freedom of design, relative to in vivo systems, has inspired the rapid development of engineering foundations for cell-free systems in recent years. These efforts have led to programmed circuits, spatially organized pathways, co-activated catalytic ensembles, rational optimization of synthetic multi-enzyme pathways, and linear scalability from the micro-liter to the 100-liter scale. It is now clear that cell-free systems offer a versatile test-bed for understanding why nature's designs work the way they do and also for enabling biosynthetic routes to novel chemicals, sustainable fuels, and new classes of tunable materials. While challenges remain, the emergence of cell-free systems is poised to open the way to novel products that until now have been impractical, if not impossible, to produce by other means. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Artificial cell mimics as simplified models for the study of cell biology.

    Science.gov (United States)

    Salehi-Reyhani, Ali; Ces, Oscar; Elani, Yuval

    2017-07-01

    Living cells are hugely complex chemical systems composed of a milieu of distinct chemical species (including DNA, proteins, lipids, and metabolites) interconnected with one another through a vast web of interactions: this complexity renders the study of cell biology in a quantitative and systematic manner a difficult task. There has been an increasing drive towards the utilization of artificial cells as cell mimics to alleviate this, a development that has been aided by recent advances in artificial cell construction. Cell mimics are simplified cell-like structures, composed from the bottom-up with precisely defined and tunable compositions. They allow specific facets of cell biology to be studied in isolation, in a simplified environment where control of variables can be achieved without interference from a living and responsive cell. This mini-review outlines the core principles of this approach and surveys recent key investigations that use cell mimics to address a wide range of biological questions. It will also place the field in the context of emerging trends, discuss the associated limitations, and outline future directions of the field. Impact statement Recent years have seen an increasing drive to construct cell mimics and use them as simplified experimental models to replicate and understand biological phenomena in a well-defined and controlled system. By summarizing the advances in this burgeoning field, and using case studies as a basis for discussion on the limitations and future directions of this approach, it is hoped that this minireview will spur others in the experimental biology community to use artificial cells as simplified models with which to probe biological systems.

  9. CellNet: network biology applied to stem cell engineering.

    Science.gov (United States)

    Cahan, Patrick; Li, Hu; Morris, Samantha A; Lummertz da Rocha, Edroaldo; Daley, George Q; Collins, James J

    2014-08-14

    Somatic cell reprogramming, directed differentiation of pluripotent stem cells, and direct conversions between differentiated cell lineages represent powerful approaches to engineer cells for research and regenerative medicine. We have developed CellNet, a network biology platform that more accurately assesses the fidelity of cellular engineering than existing methodologies and generates hypotheses for improving cell derivations. Analyzing expression data from 56 published reports, we found that cells derived via directed differentiation more closely resemble their in vivo counterparts than products of direct conversion, as reflected by the establishment of target cell-type gene regulatory networks (GRNs). Furthermore, we discovered that directly converted cells fail to adequately silence expression programs of the starting population and that the establishment of unintended GRNs is common to virtually every cellular engineering paradigm. CellNet provides a platform for quantifying how closely engineered cell populations resemble their target cell type and a rational strategy to guide enhanced cellular engineering. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. The Impact of Epigenetics on Mesenchymal Stem Cell Biology.

    Science.gov (United States)

    Ozkul, Yusuf; Galderisi, Umberto

    2016-11-01

    Changes in epigenetic marks are known to be important regulatory factors in stem cell fate determination and differentiation. In the past years, the investigation of the epigenetic regulation of stem cell biology has largely focused on embryonic stem cells (ESCs). Contrarily, less is known about the epigenetic control of gene expression during differentiation of adult stem cells (AdSCs). Among AdSCs, mesenchymal stem cells (MSCs) are the most investigated stem cell population because of their enormous potential for therapeutic applications in regenerative medicine and tissue engineering. In this review, we analyze the main studies addressing the epigenetic changes in MSC landscape during in vitro cultivation and replicative senescence, as well as follow osteocyte, chondrocyte, and adipocyte differentiation. In these studies, histone acetylation, DNA methylation, and miRNA expression are among the most investigated phenomena. We describe also epigenetic changes that are associated with in vitro MSC trans-differentiation. Although at the at initial stage, the epigenetics of MSCs promise to have profound implications for stem cell basic and applied research. J. Cell. Physiol. 231: 2393-2401, 2016. © 2016 Wiley Periodicals, Inc.

  11. Microscale methods to investigate and manipulate multispecies biological systems

    Science.gov (United States)

    Fong, Erika Jo

    This thesis details the development of a continuous perfusion platform capable of more closely mimicking in vivo cell-virus dynamics, while surpassing the experimental control and flexibility of standard cell culture. First, a microfluidic flow through acoustic device is optimized to enable efficient and controllable separation of cells and viruses. Repeatable isolation of cell and virus species is demonstrated with both a well-characterized virus, Dengue Virus (DENV), and the novel Golden Gate Virus. Next, a platform is built around this device to enable controllable, automated, continuous cell culture. Beads are used to assess system performance and optimize operation. Subsequently, the platform is used to culture both murine hybridoma (4G2) and human monocyte (THP-1) cell lines for over one month, and demonstrate the ability to manipulate population dynamics. Finally, we use the platform to establish a multispecies culture with THP-1 cells and Sindbis Virus (SINV). This work integrates distinct engineering feats to create a platform capable of enhancing existing cell virus studies and opening the door to a variety of high-impact investigations. (Abstract shortened by ProQuest.).

  12. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox

    2011-01-01

    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  13. Seeing Cells: Teaching the Visual/Verbal Rhetoric of Biology

    Science.gov (United States)

    Dinolfo, John; Heifferon, Barbara; Temesvari, Lesly A.

    2007-01-01

    This pilot study obtained baseline information on verbal and visual rhetorics to teach microscopy techniques to college biology majors. We presented cell images to students in cell biology and biology writing classes and then asked them to identify textual, verbal, and visual cues that support microscopy learning. Survey responses suggest that…

  14. In silico cell biology and biochemistry: a systems biology approach

    OpenAIRE

    Camacho, Diogo Mayo

    2007-01-01

    In the post-"omic" era the analysis of high-throughput data is regarded as one of the major challenges faced by researchers. One focus of this data analysis is uncovering biological network topologies and dynamics. It is believed that this kind of research will allow the development of new mathematical models of biological systems as well as aid in the improvement of already existing ones. The work that is presented in this dissertation addresses the problem of the analysis of highly complex ...

  15. Towards a whole-cell modeling approach for synthetic biology

    Science.gov (United States)

    Purcell, Oliver; Jain, Bonny; Karr, Jonathan R.; Covert, Markus W.; Lu, Timothy K.

    2013-06-01

    Despite rapid advances over the last decade, synthetic biology lacks the predictive tools needed to enable rational design. Unlike established engineering disciplines, the engineering of synthetic gene circuits still relies heavily on experimental trial-and-error, a time-consuming and inefficient process that slows down the biological design cycle. This reliance on experimental tuning is because current modeling approaches are unable to make reliable predictions about the in vivo behavior of synthetic circuits. A major reason for this lack of predictability is that current models view circuits in isolation, ignoring the vast number of complex cellular processes that impinge on the dynamics of the synthetic circuit and vice versa. To address this problem, we present a modeling approach for the design of synthetic circuits in the context of cellular networks. Using the recently published whole-cell model of Mycoplasma genitalium, we examined the effect of adding genes into the host genome. We also investigated how codon usage correlates with gene expression and find agreement with existing experimental results. Finally, we successfully implemented a synthetic Goodwin oscillator in the whole-cell model. We provide an updated software framework for the whole-cell model that lays the foundation for the integration of whole-cell models with synthetic gene circuit models. This software framework is made freely available to the community to enable future extensions. We envision that this approach will be critical to transforming the field of synthetic biology into a rational and predictive engineering discipline.

  16. Spectroscopic investigations of surface deposited biological warfare simulants

    Science.gov (United States)

    Barrington, Stephen J.; Bird, Hilary; Hurst, Daniel; McIntosh, Alastair J. S.; Spencer, Phillippa; Pelfrey, Suzanne H.; Baker, Matthew J.

    2012-06-01

    This paper reports a proof-of-principle study aimed at discriminating biological warfare (BW) simulants from common environmental bacteria in order to differentiate pathogenic endospores in situ, to aid any required response for hazard management. We used FTIR spectroscopy combined with multivariate analysis; FTIR is a versatile technique for the non-destructive analysis of a range of materials. We also report an evaluation of multiple pre-processing techniques and subsequent differences in cross-validation accuracy of two pattern recognition models (Support Vector Machines (SVM) and Principal Component - Linear Discriminant Analysis (PC-LDA)) for two classifications: a two class classification (Gram + ve spores vs. Gram -ve vegetative cells) and a six class classification (bacterial classification). Six bacterial strains Bacillus atrophaeus, Bacillus thuringiensis var. kurstaki, Bacillus thuringiensis, Escherichia coli, Pantaeoa agglomerans and Pseudomonas fluorescens were analysed.

  17. The biology of circulating tumor cells.

    Science.gov (United States)

    Pantel, K; Speicher, M R

    2016-03-10

    Metastasis is a biologically complex process consisting of numerous stochastic events which may tremendously differ across various cancer types. Circulating tumor cells (CTCs) are cells that are shed from primary tumors and metastatic deposits into the blood stream. CTCs bear a tremendous potential to improve our understanding of steps involved in the metastatic cascade, starting from intravasation of tumor cells into the circulation until the formation of clinically detectable metastasis. These efforts were propelled by novel high-resolution approaches to dissect the genomes and transcriptomes of CTCs. Furthermore, capturing of viable CTCs has paved the way for innovative culturing technologies to study fundamental characteristics of CTCs such as invasiveness, their kinetics and responses to selection barriers, such as given therapies. Hence the study of CTCs is not only instrumental as a basic research tool, but also allows the serial monitoring of tumor genotypes and may therefore provide predictive and prognostic biomarkers for clinicians. Here, we review how CTCs have contributed to significant insights into the metastatic process and how they may be utilized in clinical practice.

  18. Biologicals and Fetal Cell Therapy for Wound and Scar Management

    OpenAIRE

    Hirt-Burri, Nathalie; Ramelet, Albert-Adrien; Raffoul, Wassim; de Buys Roessingh, Anthony; Scaletta, Corinne; Pioletti, Dominique; Applegate, Lee Ann

    2011-01-01

    Few biopharmaceutical preparations developed from biologicals are available for tissue regeneration and scar management. When developing biological treatments with cellular therapy, selection of cell types and establishment of consistent cell banks are crucial steps in whole-cell bioprocessing. Various cell types have been used in treatment of wounds to reduce scar to date including autolog and allogenic skin cells, platelets, placenta, and amniotic extracts. Experience with fetal cells show ...

  19. Cell biology apps for Apple devices.

    Science.gov (United States)

    Stark, Louisa A

    2012-01-01

    Apps for touch-pad devices hold promise for guiding and supporting learning. Students may use them in the classroom or on their own for didactic instruction, just-in-time learning, or review. Since Apple touch-pad devices (i.e., iPad and iPhone) have a substantial share of the touch-pad device market (Campbell, 2012), this Feature will explore cell biology apps available from the App Store. My review includes iPad and iPhone apps available in June 2012, but does not include courses, lectures, podcasts, audiobooks, texts, or other books. I rated each app on a five-point scale (1 star = lowest; 5 stars = highest) for educational and production values; I also provide an overall score.

  20. The emerging age of cell-free synthetic biology.

    Science.gov (United States)

    Smith, Mark Thomas; Wilding, Kristen M; Hunt, Jeremy M; Bennett, Anthony M; Bundy, Bradley C

    2014-08-25

    The engineering of and mastery over biological parts has catalyzed the emergence of synthetic biology. This field has grown exponentially in the past decade. As increasingly more applications of synthetic biology are pursued, more challenges are encountered, such as delivering genetic material into cells and optimizing genetic circuits in vivo. An in vitro or cell-free approach to synthetic biology simplifies and avoids many of the pitfalls of in vivo synthetic biology. In this review, we describe some of the innate features that make cell-free systems compelling platforms for synthetic biology and discuss emerging improvements of cell-free technologies. We also select and highlight recent and emerging applications of cell-free synthetic biology. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  1. From cell biology to the microbiome: An intentional infinite loop

    OpenAIRE

    Garrett, Wendy S

    2015-01-01

    Cell biology is the study of the structure and function of the unit or units of living organisms. Enabled by current and evolving technologies, cell biologists today are embracing new scientific challenges that span many disciplines. The eclectic nature of cell biology is core to its future and remains its enduring legacy.

  2. From cell biology to the microbiome: An intentional infinite loop.

    Science.gov (United States)

    Garrett, Wendy S

    2015-07-01

    Cell biology is the study of the structure and function of the unit or units of living organisms. Enabled by current and evolving technologies, cell biologists today are embracing new scientific challenges that span many disciplines. The eclectic nature of cell biology is core to its future and remains its enduring legacy.

  3. Cell Biology of Thiazide Bone Effects

    Science.gov (United States)

    Gamba, Gerardo; Riccardi, Daniela

    2008-09-01

    The thiazide-sensitive Na+:Cl- cotransporter (NCC) is the major pathway for salt reabsorption in the mammalian kidney. The activity of NCC is not only related to salt metabolism, but also to calcium and magnesium homeostasis due to the inverse relationship between NCC activity and calcium reabsorption. Hence, the thiazide-type diuretics that specifically block NCC have been used for years, not only for treatment of hypertension and edematous disease, but also for the management of renal stone disease. Epidemiological studies have shown that chronic thiazide treatment is associated with higher bone mineral density and reduced risk of bone fractures, which can only partly be explained in terms of their effects on the kidney. In this regard, we have recently shown that NCC is expressed in bone cells and that inhibition of NCC in bone, either by thiazides or by reduction of NCC protein with specific siRNA, is associated with increased mineralization in vitro. These observations open a field of study to begin to understand the cell biology of the beneficial effects of thiazides in bone.

  4. Computational cell biology at the home of the helix.

    Science.gov (United States)

    Ward, Jonathan J; Nédélec, Francois J

    2010-06-01

    The Computational Cell Biology Conference, held jointly by the Cold Spring Harbor Laboratory and the Wellcome Trust, was convened in the grand surroundings of Hinxton Hall near Cambridge, UK. The high quality of the research presented at the meeting confirmed that the field of computational cell biology is maturing rapidly, which mirrors the progression of cell biology from being mostly descriptive to a more quantitative discipline.

  5. Molecular self-assembly for biological investigations and nanoscale lithography

    Science.gov (United States)

    Cheunkar, Sarawut

    Small, diffusible molecules when recognized by their binding partners, such as proteins and antibodies, trigger enzymatic activity, cell communication, and immune response. Progress in analytical methods enabling detection, characterization, and visualization of biological dynamics at the molecular level will advance our exploration of complex biological systems. In this dissertation, analytical platforms were fabricated to capture membrane-associated receptors, which are essential proteins in cell signaling pathways. The neurotransmitter serotonin and its biological precursor were immobilized on gold substrates coated with self-assembled monolayers (SAMs) of oligo(ethylene glycol)alkanethiols and their reactive derivatives. The SAM-coated substrates present the biologically selective affinity of immobilized molecules to target native membrane-associated receptors. These substrates were also tested for biospecificity using antibodies. In addition, small-molecule-functionalized platforms, expressing neurotransmitter pharmacophores, were employed to examine kinetic interactions between G-protein-coupled receptors and their associated neurotransmitters. The binding interactions were monitored using a quartz crystal microbalance equipped with liquid-flow injection. The interaction kinetics of G-protein-coupled serotonin 1A receptor and 5-hydroxytyptophan-functionalized surfaces were studied in a real-time, label-free environment. Key binding parameters, such as equilibrium dissociation constants, binding rate constants, and dissociative half-life, were extracted. These parameters are critical for understanding and comparing biomolecular interactions in modern biomedical research. By integrating self-assembly, surface functionalization, and nanofabrication, small-molecule microarrays were created for high-throughput screening. A hybrid soft-lithography, called microcontact insertion printing, was used to pattern small molecules at the dilute scales necessary for highly

  6. Micrasterias as a Model System in Plant Cell Biology

    Science.gov (United States)

    Lütz-Meindl, Ursula

    2016-01-01

    The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells. PMID:27462330

  7. Micrasterias as a model system in plant cell biology

    Directory of Open Access Journals (Sweden)

    Ursula Luetz-Meindl

    2016-07-01

    Full Text Available The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its extraordinary star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 µm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

  8. Tethered bilayer lipid membranes (tBLMs): interest and applications for biological membrane investigations.

    Science.gov (United States)

    Rebaud, Samuel; Maniti, Ofelia; Girard-Egrot, Agnès P

    2014-12-01

    Biological membranes play a central role in the biology of the cell. They are not only the hydrophobic barrier allowing separation between two water soluble compartments but also a supra-molecular entity that has vital structural functions. Notably, they are involved in many exchange processes between the outside and inside cellular spaces. Accounting for the complexity of cell membranes, reliable models are needed to acquire current knowledge of the molecular processes occurring in membranes. To simplify the investigation of lipid/protein interactions, the use of biomimetic membranes is an approach that allows manipulation of the lipid composition of specific domains and/or the protein composition, and the evaluation of the reciprocal effects. Since the middle of the 80's, lipid bilayer membranes have been constantly developed as models of biological membranes with the ultimate goal to reincorporate membrane proteins for their functional investigation. In this review, after a brief description of the planar lipid bilayers as biomimetic membrane models, we will focus on the construction of the tethered Bilayer Lipid Membranes, the most promising model for efficient membrane protein reconstitution and investigation of molecular processes occurring in cell membranes. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Systems biology approaches and pathway tools for investigating cardiovascular disease

    NARCIS (Netherlands)

    Wheelock, C.E.; Wheelock, A.M.; Kawashima, S.; Diez, D.; Kanehisa, M.; Erk, M. van; Kleemann, R.; Haeggström, J.Z.; Goto, S.

    2009-01-01

    Systems biology aims to understand the nonlinear interactions of multiple biomolecular components that characterize a living organism. One important aspect of systems biology approaches is to identify the biological pathways or networks that connect the differing elements of a system, and examine ho

  10. Biology of Metastatic Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Michele Milella, Alessandra Felici

    2011-01-01

    cell biology and tumor-host interactions may hold the key to future advances in such a complex and challenging disease.

  11. Beyond the Biology: A Systematic Investigation of Noncontent Instructor Talk in an Introductory Biology Course.

    Science.gov (United States)

    Seidel, Shannon B; Reggi, Amanda L; Schinske, Jeffrey N; Burrus, Laura W; Tanner, Kimberly D

    2015-01-01

    Instructors create classroom environments that have the potential to impact learning by affecting student motivation, resistance, and self-efficacy. However, despite the critical importance of the learning environment in increasing conceptual understanding, little research has investigated what instructors say and do to create learning environments in college biology classrooms. We systematically investigated the language used by instructors that does not directly relate to course content and defined the construct of Instructor Talk. Transcripts were generated from a semester-long, cotaught introductory biology course (n = 270 students). Transcripts were analyzed using a grounded theory approach to identify emergent categories of Instructor Talk. The five emergent categories from analysis of more than 600 quotes were, in order of prevalence, 1) Building the Instructor/Student Relationship, 2) Establishing Classroom Culture, 3) Explaining Pedagogical Choices, 4) Sharing Personal Experiences, and 5) Unmasking Science. Instances of Instructor Talk were present in every class session analyzed and ranged from six to 68 quotes per session. The Instructor Talk framework is a novel research variable that could yield insights into instructor effectiveness, origins of student resistance, and methods for overcoming stereotype threat. Additionally, it holds promise in professional development settings to assist instructors in reflecting on the learning environments they create.

  12. ``Physical Concepts in Cell Biology,'' an upper level interdisciplinary course in cell biophysics/mathematical biology

    Science.gov (United States)

    Vavylonis, Dimitrios

    2009-03-01

    I will describe my experience in developing an interdisciplinary biophysics course addressed to students at the upper undergraduate and graduate level, in collaboration with colleagues in physics and biology. The students had a background in physics, biology and engineering, and for many the course was their first exposure to interdisciplinary topics. The course did not depend on a formal knowledge of equilibrium statistical mechanics. Instead, the approach was based on dynamics. I used diffusion as a universal ``long time'' law to illustrate scaling concepts. The importance of statistics and proper counting of states/paths was introduced by calculating the maximum accuracy with which bacteria can measure the concentration of diffuse chemicals. The use of quantitative concepts and methods was introduced through specific biological examples, focusing on model organisms and extremes at the cell level. Examples included microtubule dynamic instability, the search and capture model, molecular motor cooperativity in muscle cells, mitotic spindle oscillations in C. elegans, polymerization forces and propulsion of pathogenic bacteria, Brownian ratchets, bacterial cell division and MinD oscillations.

  13. Study on biological characters of SGC7901 gastric cancer cell-dendritic cell fusion vaccines

    Institute of Scientific and Technical Information of China (English)

    Kun Zhang; Peng-Fen Gao; Pei-Wu Yu; Yun Rao; Li-Xin Zhou

    2006-01-01

    AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines.METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned by polyethylene glycol. Pure fusion cells were obtained by selective culture with the HAT/HT culture systems.The fusion cells were counted at different time points of culture and their growth curves were drawn to reflect their proliferative activities. The fusion cells were also cultured in culture medium to investigate whether they could grow into cell clones. MTT method was used to test the stimulating abilities of the fusion cells on T lymphocytes' proliferations. Moreover, the fusion cells were planted into nude mice to observe whether they could grow into new planted tumors in this kind of immunodeficiency animals.RESULTS: The fusion cells had weaker proliferative activity and clone abilities than their parental cells. When they were cultured, the counts of cells did not increase remarkably, nor could they grow into cell clones in culture medium. The fusion cells could not grow into new planted tumors after planted into nude mice. The stimulating abilities of the fusion cells on T lymphocytes' proliferations were remarkably increased than their parental dendritic cells.CONCLUSION: The SGC7901 gastric cancer cell-dendritic cell fusion vaccines have much weaker proliferative abilities than their parental cells, but they keep strong abilities to irritate the T lymphocytes and have no abilities to grow into new planted tumors in immunodeficiency animals. These are the biological basis for their antitumor biotherapies.

  14. Investigating the Efficiency of Biological Filters for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    S Motesaddi Zarandi, MR Massoudinejad, A Mazaheri Tehrani, H Pouri

    2013-09-01

    Full Text Available Backgrounds and Aims: Ammonia removal from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. Materials and Methods: According to the ammonia removal method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1:4. In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm at a temperature of 25 degrees Celsius. Results: The results of this study showed that efficiency is decreased when the flow rate or concentration is increased because the microbial population is reduced. The efficiency was reduced by 84.6-98.2 percent. Maximum efficiency occurred at a 0.19g/(m3.h loading rate. Efficiency was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT of 240 seconds. Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia removal from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.

  15. Stem cells: Biology and clinical potential

    African Journals Online (AJOL)

    ajl yemi

    2011-12-30

    Dec 30, 2011 ... divisions to self renew or undergo terminal differentiation, or they may ... cells, hematopoietic stem cells and cancer cells conti- ..... as vascular endothelial cells, neurocytes, lung cells and ..... Patient-specific embryonic stem.

  16. Genome Annotation in a Community College Cell Biology Lab

    Science.gov (United States)

    Beagley, C. Timothy

    2013-01-01

    The Biology Department at Salt Lake Community College has used the IMG-ACT toolbox to introduce a genome mapping and annotation exercise into the laboratory portion of its Cell Biology course. This project provides students with an authentic inquiry-based learning experience while introducing them to computational biology and contemporary learning…

  17. Genome Annotation in a Community College Cell Biology Lab

    Science.gov (United States)

    Beagley, C. Timothy

    2013-01-01

    The Biology Department at Salt Lake Community College has used the IMG-ACT toolbox to introduce a genome mapping and annotation exercise into the laboratory portion of its Cell Biology course. This project provides students with an authentic inquiry-based learning experience while introducing them to computational biology and contemporary learning…

  18. Review: Biological relevance of disseminated tumor cells in cancer patients.

    Science.gov (United States)

    Riethdorf, Sabine; Wikman, Harriet; Pantel, Klaus

    2008-11-01

    The prognosis of cancer patients is largely determined by the occurrence of distant metastases. In patients with primary tumors, this relapse is mainly due to clinically occult micrometastasis present in secondary organs at primary diagnosis but not detectable even with high resolution imaging procedures. Sensitive and specific immunocytochemical and molecular assays enable the detection and characterization of disseminated tumor cells (DTC) at the single cell level in bone marrow (BM) as the common homing site of DTC and circulating tumor cells (CTC) in peripheral blood. Because of the high variability of results in DTC and CTC detection, there is an urgent need for standardized methods. In this review, we will focus on BM and present currently available methods for the detection and characterization of DTC. Furthermore, we will discuss data on the biology of DTC and the clinical relevance of DTC detection. While the prognostic impact of DTC in BM has clearly been shown for primary breast cancer patients, less is known about the clinical relevance of DTC in patients with other carcinomas. Current findings suggest that DTC are capable to survive chemotherapy and persist in a dormant nonproliferating state over years. To what extent these DTC have stem cell properties is subject of ongoing investigations. Further characterization is required to understand the biology of DTC and to identify new targets for improved risk prevention and tailoring of therapy. Our review will focus on breast, colon, lung, and prostate cancer as the main tumor entities in Europe and the United States.

  19. Synthetic biology: programming cells for biomedical applications.

    Science.gov (United States)

    Hörner, Maximilian; Reischmann, Nadine; Weber, Wilfried

    2012-01-01

    The emerging field of synthetic biology is a novel biological discipline at the interface between traditional biology, chemistry, and engineering sciences. Synthetic biology aims at the rational design of complex synthetic biological devices and systems with desired properties by combining compatible, modular biological parts in a systematic manner. While the first engineered systems were mainly proof-of-principle studies to demonstrate the power of the modular engineering approach of synthetic biology, subsequent systems focus on applications in the health, environmental, and energy sectors. This review describes recent approaches for biomedical applications that were developed along the synthetic biology design hierarchy, at the level of individual parts, of devices, and of complex multicellular systems. It describes how synthetic biological parts can be used for the synthesis of drug-delivery tools, how synthetic biological devices can facilitate the discovery of novel drugs, and how multicellular synthetic ecosystems can give insight into population dynamics of parasites and hosts. These examples demonstrate how this new discipline could contribute to novel solutions in the biopharmaceutical industry.

  20. Industrial systems biology and its impact on synthetic biology of yeast cell factories.

    Science.gov (United States)

    Fletcher, Eugene; Krivoruchko, Anastasia; Nielsen, Jens

    2016-06-01

    Engineering industrial cell factories to effectively yield a desired product while dealing with industrially relevant stresses is usually the most challenging step in the development of industrial production of chemicals using microbial fermentation processes. Using synthetic biology tools, microbial cell factories such as Saccharomyces cerevisiae can be engineered to express synthetic pathways for the production of fuels, biopharmaceuticals, fragrances, and food flavors. However, directing fluxes through these synthetic pathways towards the desired product can be demanding due to complex regulation or poor gene expression. Systems biology, which applies computational tools and mathematical modeling to understand complex biological networks, can be used to guide synthetic biology design. Here, we present our perspective on how systems biology can impact synthetic biology towards the goal of developing improved yeast cell factories. Biotechnol. Bioeng. 2016;113: 1164-1170. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  1. A Diagnostic Assessment for Introductory Molecular and Cell Biology

    Science.gov (United States)

    Shi, Jia; Wood, William B.; Martin, Jennifer M.; Guild, Nancy A.; Vicens, Quentin; Knight, Jennifer K.

    2010-01-01

    We have developed and validated a tool for assessing understanding of a selection of fundamental concepts and basic knowledge in undergraduate introductory molecular and cell biology, focusing on areas in which students often have misconceptions. This multiple-choice Introductory Molecular and Cell Biology Assessment (IMCA) instrument is designed…

  2. A Diagnostic Assessment for Introductory Molecular and Cell Biology

    Science.gov (United States)

    Shi, Jia; Wood, William B.; Martin, Jennifer M.; Guild, Nancy A.; Vicens, Quentin; Knight, Jennifer K.

    2010-01-01

    We have developed and validated a tool for assessing understanding of a selection of fundamental concepts and basic knowledge in undergraduate introductory molecular and cell biology, focusing on areas in which students often have misconceptions. This multiple-choice Introductory Molecular and Cell Biology Assessment (IMCA) instrument is designed…

  3. Cell Biology and Microbiology: A Continuous Cross-Feeding.

    Science.gov (United States)

    Pizarro-Cerdá, Javier; Cossart, Pascale

    2016-07-01

    Microbiology and cell biology both involve the study of cells, albeit at different levels of complexity and scale. Interactions between both fields during the past 25 years have led to major conceptual and technological advances that have reshaped the whole biology landscape and its biomedical applications.

  4. Investigating cell sorting and analysis of the proprietary cell-BOCS platform

    DEFF Research Database (Denmark)

    Carrissemoux, Caro; Beunis, Filip; Glückstad, Jesper

    2016-01-01

    This project comprises investigation of cell sorting, of both artificial beads and biological cells, and analysis of the proprietary cell-BOCS - Bio Optofluidic Cell Sorter, a table top cell sorter using optical manipulation. The analysis is more specific on broadening the ways of detection of ce...... modulated laser beam. The anticipated project output is a cheap, compact and easy-to-operate cell sorter that is able to detect and manipulate fluorescent microspheres, fluorescent labelled yeast cells and potentially erythrocytes in a microfluidic stream....

  5. Endothelial progenitor cell biology in ankylosing spondylitis.

    Science.gov (United States)

    Verma, Inderjeet; Syngle, Ashit; Krishan, Pawan

    2015-03-01

    Endothelial progenitor cells (EPCs) are unique populations which have reparative potential in overcoming endothelial damage and reducing cardiovascular risk. Patients with ankylosing spondylitis (AS) have increased risk of cardiovascular morbidity and mortality. The aim of this study was to investigate the endothelial progenitor cell population in AS patients and its potential relationships with disease variables. Endothelial progenitor cells were measured in peripheral blood samples from 20 AS and 20 healthy controls by flow cytometry on the basis of CD34 and CD133 expression. Disease activity was evaluated by using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Functional ability was monitored by using Bath Ankylosing Spondylitis Functional Index (BASFI). EPCs were depleted in AS patients as compared to healthy controls (CD34(+) /CD133(+) : 0.027 ± 0.010% vs. 0.044 ± 0.011%, P < 0.001). EPC depletions were significantly associated with disease duration (r = -0.52, P = 0.01), BASDAI (r = -0.45, P = 0.04) and C-reactive protein (r = -0.5, P = 0.01). This is the first study to demonstrate endothelial progenitor cell depletion in AS patients. EPC depletions inversely correlate with disease duration, disease activity and inflammation, suggesting the pivotal role of inflammation in depletion of EPCs. EPC would possibly also serve as a therapeutic target for preventing cardiovascular disease in AS. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  6. Classical investigation of long-range coherence in biological systems

    Science.gov (United States)

    Preto, Jordane

    2016-12-01

    Almost five decades ago, H. Fröhlich [H. Fröhlich, "Long-range coherence and energy storage in biological systems," Int. J. Quantum Chem. 2(5), 641-649 (1968)] reported, on a theoretical basis, that the excitation of quantum modes of vibration in contact with a thermal reservoir may lead to steady states, where under high enough rate of energy supply, only specific low-frequency modes of vibration are strongly excited. This nonlinear phenomenon was predicted to occur in biomolecular systems, which are known to exhibit complex vibrational spectral properties, especially in the terahertz frequency domain. However, since the effects of terahertz or lower-frequency modes are mainly classical at physiological temperatures, there are serious doubts that Fröhlich's quantum description can be applied to predict such a coherent behavior in a biological environment, as suggested by the author. In addition, a quantum formalism makes the phenomenon hard to investigate using realistic molecular dynamics simulations (MD) as they are usually based on the classical principles. In the current paper, we provide a general classical Hamiltonian description of a nonlinear open system composed of many degrees of freedom (biomolecular structure) excited by an external energy source. It is shown that a coherent behaviour similar to Fröhlich's effect is to be expected in the classical case for a given range of parameter values. Thus, the supplied energy is not completely thermalized but stored in a highly ordered fashion. The connection between our Hamiltonian description, carried out in the space of normal modes, and a more standard treatment in the physical space is emphasized in order to facilitate the prediction of the effect from MD simulations. It is shown how such a coherent phenomenon may induce long-range resonance effects that could be of critical importance at the biomolecular level. The present work is motivated by recent experimental evidences of long-lived excited low

  7. The Histochemistry and Cell Biology compendium: a review of 2012.

    Science.gov (United States)

    Taatjes, Douglas J; Roth, Jürgen

    2013-06-01

    The year 2012 was another exciting year for Histochemistry and Cell Biology. Innovations in immunohistochemical techniques and microscopy-based imaging have provided the means for advances in the field of cell biology. Over 130 manuscripts were published in the journal during 2012, representing methodological advancements, pathobiology of disease, and cell and tissue biology. This annual review of the manuscripts published in the previous year in Histochemistry and Cell Biology serves as an abbreviated reference for the readership to quickly peruse and discern trends in the field over the past year. The review has been broadly divided into multiple sections encompassing topics such as method advancements, subcellular components, extracellular matrix, and organ systems. We hope that the creation of this subdivision will serve to guide the reader to a specific topic of interest, while simultaneously providing a concise and easily accessible encapsulation of other topics in the broad area of Histochemistry and Cell Biology.

  8. Silicon Carbide Solar Cells Investigated

    Science.gov (United States)

    Bailey, Sheila G.; Raffaelle, Ryne P.

    2001-01-01

    The semiconductor silicon carbide (SiC) has long been known for its outstanding resistance to harsh environments (e.g., thermal stability, radiation resistance, and dielectric strength). However, the ability to produce device-quality material is severely limited by the inherent crystalline defects associated with this material and their associated electronic effects. Much progress has been made recently in the understanding and control of these defects and in the improved processing of this material. Because of this work, it may be possible to produce SiC-based solar cells for environments with high temperatures, light intensities, and radiation, such as those experienced by solar probes. Electronics and sensors based on SiC can operate in hostile environments where conventional silicon-based electronics (limited to 350 C) cannot function. Development of this material will enable large performance enhancements and size reductions for a wide variety of systems--such as high-frequency devices, high-power devices, microwave switching devices, and high-temperature electronics. These applications would supply more energy-efficient public electric power distribution and electric vehicles, more powerful microwave electronics for radar and communications, and better sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines. The 6H-SiC polytype is a promising wide-bandgap (Eg = 3.0 eV) semiconductor for photovoltaic applications in harsh solar environments that involve high-temperature and high-radiation conditions. The advantages of this material for this application lie in its extremely large breakdown field strength, high thermal conductivity, good electron saturation drift velocity, and stable electrical performance at temperatures as high as 600 C. This behavior makes it an attractive photovoltaic solar cell material for devices that can operate within three solar radii of the Sun.

  9. Biological Applications and Transmission Electron Microscopy Investigations of Mesoporous Silica Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G. [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    The research presented and discussed within involves the development of novel biological applications of mesoporous silica nanoparticles (MSN) and an investigation of mesoporous material by transmission electron microscopy (TEM). Mesoporous silica nanoparticles organically functionalized shown to undergo endocytosis in cancer cells and drug release from the pores was controlled intracellularly and intercellularly. Transmission electron microscopy investigations demonstrated the variety of morphologies produced in this field of mesoporous silica nanomaterial synthesis. A series of room-temperature ionic liquid (RTIL) containing mesoporous silica nanoparticle (MSN) materials with various particle morphologies, including spheres, ellipsoids, rods, and tubes, were synthesized. By changing the RTIL template, the pore morphology was tuned from the MCM-41 type of hexagonal mesopores to rotational moire type of helical channels, and to wormhole-like porous structures. These materials were used as controlled release delivery nanodevices to deliver antibacterial ionic liquids against Escherichia coli K12. The involvement of a specific organosiloxane function group, covalently attached to the exterior of fluorescein doped mesoporous silica nanoparticles (FITC-MSN), on the degree and kinetics of endocytosis in cancer and plant cells was investigated. The kinetics of endocystosis of TEG coated FITC-MSN is significantly quicker than FITC-MSN as determined by flow cytometry experiments. The fluorescence confocal microscopy investigation showed the endocytosis of TEG coated-FITC MSN triethylene glycol grafted fluorescein doped MSN (TEG coated-FITC MSN) into both KeLa cells and Tobacco root protoplasts. Once the synthesis of a controlled-release delivery system based on MCM-41-type mesoporous silica nanorods capped by disulfide bonds with superparamagnetic iron oxide nanoparticles was completed. The material was characterized by general methods and the dosage and kinetics of the

  10. Toward Network Biology in E. coli Cell.

    Science.gov (United States)

    Mori, Hirotada; Takeuchi, Rikiya; Otsuka, Yuta; Bowden, Steven; Yokoyama, Katsushi; Muto, Ai; Libourel, Igor; Wanner, Barry L

    2015-01-01

    E. coli has been a critically important model research organism for more than 50 years, particularly in molecular biology. In 1997, the E. coli draft genome sequence was published. Post-genomic techniques and resources were then developed that allowed E. coli to become a model organism for systems biology. Progress made since publication of the E. coli genome sequence will be summarized.

  11. Crosstalk between stromal cells and cancer cells in pancreatic cancer: New insights into stromal biology.

    Science.gov (United States)

    Zhan, Han-Xiang; Zhou, Bin; Cheng, Yu-Gang; Xu, Jian-Wei; Wang, Lei; Zhang, Guang-Yong; Hu, San-Yuan

    2017-04-28

    Pancreatic cancer (PC) remains one of the most lethal malignancies worldwide. Increasing evidence has confirmed the pivotal role of stromal components in the regulation of carcinogenesis, invasion, metastasis, and therapeutic resistance in PC. Interaction between neoplastic cells and stromal cells builds a specific microenvironment, which further modulates the malignant properties of cancer cells. Instead of being a "passive bystander", stroma may play a role as a "partner in crime" in PC. However, the role of stromal components in PC is complex and requires further investigation. In this article, we review recent advances regarding the regulatory roles and mechanisms of stroma biology, especially the cellular components such as pancreatic stellate cells, macrophages, neutrophils, adipocytes, epithelial cells, pericytes, mast cells, and lymphocytes, in PC. Crosstalk between stromal cells and cancer cells is thoroughly investigated. We also review the prognostic value and molecular therapeutic targets of stroma in PC. This review may help us further understand the molecular mechanisms of stromal biology and its role in PC development and therapeutic resistance. Moreover, targeting stroma components may provide new therapeutic strategies for this stubborn disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. A quick guide to light microscopy in cell biology

    Science.gov (United States)

    Thorn, Kurt

    2016-01-01

    Light microscopy is a key tool in modern cell biology. Light microscopy has several features that make it ideally suited for imaging biology in living cells: the resolution is well-matched to the sizes of subcellular structures, a diverse range of available fluorescent probes makes it possible to mark proteins, organelles, and other structures for imaging, and the relatively nonperturbing nature of light means that living cells can be imaged for long periods of time to follow their dynamics. Here I provide a brief introduction to using light microscopy in cell biology, with particular emphasis on factors to be considered when starting microscopy experiments. PMID:26768859

  13. Discovery of HeLa Cell Contamination in HES Cells: Call for Cell Line Authentication in Reproductive Biology Research.

    Science.gov (United States)

    Kniss, Douglas A; Summerfield, Taryn L

    2014-08-01

    Continuous cell lines are used frequently in reproductive biology research to study problems in early pregnancy events and parturition. It has been recognized for 50 years that many mammalian cell lines contain inter- or intraspecies contaminations with other cells. However, most investigators do not routinely test their culture systems for cross-contamination. The most frequent contributor to cross-contamination of cell lines is the HeLa cell isolated from an aggressive cervical adenocarcinoma. We report on the discovery of HeLa cell contamination of the human endometrial epithelial cell line HES isolated in our laboratory. Short tandem repeat analysis of 9 unique genetic loci demonstrated molecular identity between HES and HeLa cells. In addition, we verified that WISH cells, isolated originally from human amnion epithelium, were also contaminated with HeLa cells. Inasmuch as our laboratory did not culture HeLa cells at the time of HES cell derivations, the source of contamination was the WISH cell line. These data highlight the need for continued diligence in authenticating cell lines used in reproductive biology research. © The Author(s) 2014.

  14. Learning Cell Biology as a Team: A Project-Based Approach to Upper-Division Cell Biology

    Science.gov (United States)

    Wright, Robin; Boggs, James

    2002-01-01

    To help students develop successful strategies for learning how to learn and communicate complex information in cell biology, we developed a quarter-long cell biology class based on team projects. Each team researches a particular human disease and presents information about the cellular structure or process affected by the disease, the cellular…

  15. Learning Cell Biology as a Team: A Project-Based Approach to Upper-Division Cell Biology

    Science.gov (United States)

    Wright, Robin; Boggs, James

    2002-01-01

    To help students develop successful strategies for learning how to learn and communicate complex information in cell biology, we developed a quarter-long cell biology class based on team projects. Each team researches a particular human disease and presents information about the cellular structure or process affected by the disease, the cellular…

  16. Investigation on Silicon Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

  17. The Biological Study of the Cultured Human Lens Epithelial Cells in Vitro

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The human lens epithelial cells (HLE) cultured in vitro was established in normal and cataractous lenses. The biological feature, histological characteristics and the ultrastructure of the cultured HLE cells were investigated. The results reveal that the proliferative capacity of the culutured HLE cells is reversely proportional to the donour age; the cultured HLE cells has the limited proliferative capacity in vitro. The relieve of the contact inhibition is the effective trigger of the HLE cell prolife...

  18. Effects of Oxidative Stress on Mesenchymal Stem Cell Biology

    Science.gov (United States)

    2016-01-01

    Mesenchymal stromal/stem cells (MSCs) are multipotent stem cells present in most fetal and adult tissues. Ex vivo culture-expanded MSCs are being investigated for tissue repair and immune modulation, but their full clinical potential is far from realization. Here we review the role of oxidative stress in MSC biology, as their longevity and functions are affected by oxidative stress. In general, increased reactive oxygen species (ROS) inhibit MSC proliferation, increase senescence, enhance adipogenic but reduce osteogenic differentiation, and inhibit MSC immunomodulation. Furthermore, aging, senescence, and oxidative stress reduce their ex vivo expansion, which is critical for their clinical applications. Modulation of sirtuin expression and activity may represent a method to reduce oxidative stress in MSCs. These findings have important implications in the clinical utility of MSCs for degenerative and immunological based conditions. Further study of oxidative stress in MSCs is imperative in order to enhance MSC ex vivo expansion and in vivo engraftment, function, and longevity. PMID:27413419

  19. Molecular cell biology of androgen receptor signalling.

    Science.gov (United States)

    Bennett, Nigel C; Gardiner, Robert A; Hooper, John D; Johnson, David W; Gobe, Glenda C

    2010-06-01

    The classical action of androgen receptor (AR) is to regulate gene transcriptional processes via AR nuclear translocation, response element binding and recruitment of, or crosstalk with, transcription factors. AR also utilises non-classical, non-genomic mechanisms of signal transduction. These precede gene transcription or protein synthesis, and involve steroid-induced modulation of cytoplasmic or cell membrane-bound regulatory proteins. Despite many decades of investigation, the role of AR in gene regulation of cells and tissues remains only partially characterised. AR exerts most of its effects in sex hormone-dependent tissues of the body, but the receptor is also expressed in many tissues not previously thought to be androgen sensitive. Thus it is likely that a complex, more over-arching, role for AR exists. Each AR domain co-ordinates a multitude of individual and vital roles via a diverse array of interacting partner molecules that are necessary for cellular and tissue development and maintenance. Aberrant AR activity, promoted by mutations or binding partner misregulation, can present as many clinical manifestations including androgen insensitivity syndrome and prostate cancer. In the case of malignant prostate cancer, treatment generally revolves around androgen deprivation therapies designed to interfere with AR action and the androgen signalling axis. Androgen therapies for prostate cancer often fail, highlighting a real need for increased research into AR function.

  20. Cell biology: Death drags down the neighbourhood

    Science.gov (United States)

    Vasquez, Claudia G.; Martin, Adam C.

    2015-02-01

    An analysis of dying cells reveals that they play an active part in modifying tissue shape by pulling on neighbouring cells. This induces neighbouring cells to contract at their apices, which results in tissue folding. See Letter p.245

  1. Lipids in cell biology: how can we understand them better?

    Science.gov (United States)

    Muro, Eleonora; Atilla-Gokcumen, G. Ekin; Eggert, Ulrike S.

    2014-01-01

    Lipids are a major class of biological molecules and play many key roles in different processes. The diversity of lipids is on the same order of magnitude as that of proteins: cells express tens of thousands of different lipids and hundreds of proteins to regulate their metabolism and transport. Despite their clear importance and essential functions, lipids have not been as well studied as proteins. We discuss here some of the reasons why it has been challenging to study lipids and outline technological developments that are allowing us to begin lifting lipids out of their “Cinderella” status. We focus on recent advances in lipid identification, visualization, and investigation of their biophysics and perturbations and suggest that the field has sufficiently advanced to encourage broader investigation into these intriguing molecules. PMID:24925915

  2. Cell and developmental biology of arbuscular mycorrhiza symbiosis.

    Science.gov (United States)

    Gutjahr, Caroline; Parniske, Martin

    2013-01-01

    The default mineral nutrient acquisition strategy of land plants is the symbiosis with arbuscular mycorrhiza (AM) fungi. Research into the cell and developmental biology of AM revealed fascinating insights into the plasticity of plant cell development and of interorganismic communication. It is driven by the prospect of increased exploitation of AM benefits for sustainable agriculture. The plant cell developmental program for intracellular accommodation of AM fungi is activated by a genetically defined signaling pathway involving calcium spiking in the nucleus as second messenger. Calcium spiking is triggered by chitooligosaccharides released by AM fungi that are probably perceived via LysM domain receptor kinases. Fungal infection and calcium spiking are spatiotemporally coordinated, and only cells committed to accommodating the fungus undergo high-frequency spiking. Delivery of mineral nutrients by AM fungi occurs at tree-shaped hyphal structures, the arbuscules, in plant cortical cells. Nutrients are taken up at a plant-derived periarbuscular membrane, which surrounds fungal hyphae and carries a specific transporter composition that is of direct importance for symbiotic efficiency. An elegant study has unveiled a new and unexpected mechanism for specific protein localization to the periarbuscular membrane, which relies on the timing of gene expression to synchronize protein biosynthesis with a redirection of secretion. The control of AM development by phytohormones is currently subject to active investigation and has led to the rediscovery of strigolactones. Nearly all tested phytohormones regulate AM development, and major insights into the mechanisms of this regulation are expected in the near future.

  3. Industrial systems biology and its impact on synthetic biology of yeast cell factories

    DEFF Research Database (Denmark)

    Fletcher, Eugene; Krivoruchko, Anastasia; Nielsen, Jens

    2016-01-01

    Engineering industrial cell factories to effectively yield a desired product while dealing with industrially relevant stresses is usually the most challenging step in the development of industrial production of chemicals using microbial fermentation processes. Using synthetic biology tools...

  4. Numerical simulation of dielectric spectra of aqueous suspensions of non-spheroidal differently shaped biological cells

    Science.gov (United States)

    di Biasio, Antonio; Ambrosone, Luigi; Cametti, Cesare

    2009-01-01

    The effect of shape on the dielectric and conductometric spectra of aqueous suspensions of non-spheroidal biological cells has been investigated by means of numerical simulation methods. This work extends our previous investigation directed to biological cell systems where a superficial electric charge distribution is present on the outer interface of the cell membrane. This generalization results in a more composite dielectric spectra, where a low-frequency and a high-frequency contribution are expected. We consider different geometries, from ellipsoids, discoids, pear-shaped vesicles, cup-shaped vesicles to budded vesicles, which model a biological cell during different processes of biological relevance. The overview of the evolution of the dielectric spectra with the progressive change in the cell shape, maintaining constant the electrical properties of the different media involved and the fractional volume of the dispersed cells, offers a preliminary opportunity to separate contributions derived exclusively from the geometry to those due to the bulk and/or interface polarizations. These aspects are particularly relevant since dielectric spectroscopy of biological cell suspensions has proved its effectiveness in the characterization of the passive electrical properties of the cell membrane and also in controlled manipulations of biological systems.

  5. Biological applications and transmission electron microscopy investigation of mesoporous silica nanoparticles

    Science.gov (United States)

    Trewyn, Brian G.

    The research presented and discussed within involves the development of novel biological applications of mesoporous silica nanoparticles (MSN) and an investigation of mesoporous material by transmission electron microscopy (TEM). A series of room-temperature ionic liquid (RTIL) containing mesoporous silica nanoparticle (MSN) materials with various particle morphologies, including spheres, ellipsoids, rods, and tubes, were synthesized. By changing the RTIL template, the pore morphology was tuned from the MCM-41 type of hexagonal mesopores to rotational moire type of helical channels, and to wormhole-like porous structures. These materials were used as controlled release delivery nanodevices to deliver antibacterial ionic liquids against Escherichia coli K12. The involvement of a specific organosiloxane function group, covalently attached to the exterior of fluorescein doped mesoporous silica nanoparticles (FITC-MSN), on the degree and kinetics of endocytosis in cancer and plant cells was investigated. The kinetics of endocystosis of TEG coated FITC-MSN is significantly quicker than FITC-MSN as determined by flow cytometry experiments. The fluorescence confocal microscopy investigation showed the endocytosis of TEG coated-FITC MSN triethylene glycol grafted fluorescein doped MSN (TEG coated-FITC MSN) into both HeLa cells and Tobacco root protoplasts. Once the synthesis of a controlled-release delivery system based on MCM-41-type mesoporous silica nanorods capped by disulfide bonds with superparamagnetic iron oxide nanoparticles was completed. The material was characterized by general methods and the dosage and kinetics of the antioxidant dependent release was measured. Finally, the biological interaction of the material was determined along with TEM measurements. An electron microscopy investigation proved that the pore openings of the MSN were indeed blocked by the Fe 3O4 nanoparticles. The biological interaction investigation demonstrated Fe3O4-capped MSN

  6. Cell-free synthetic biology for environmental sensing and remediation.

    Science.gov (United States)

    Karig, David K

    2017-02-19

    The fields of biosensing and bioremediation leverage the phenomenal array of sensing and metabolic capabilities offered by natural microbes. Synthetic biology provides tools for transforming these fields through complex integration of natural and novel biological components to achieve sophisticated sensing, regulation, and metabolic function. However, the majority of synthetic biology efforts are conducted in living cells, and concerns over releasing genetically modified organisms constitute a key barrier to environmental applications. Cell-free protein expression systems offer a path towards leveraging synthetic biology, while preventing the spread of engineered organisms in nature. Recent efforts in the areas of cell-free approaches for sensing, regulation, and metabolic pathway implementation, as well as for preserving and deploying cell-free expression components, embody key steps towards realizing the potential of cell-free systems for environmental sensing and remediation.

  7. Embryonic stem cell biology: insights from molecular imaging.

    Science.gov (United States)

    Sallam, Karim; Wu, Joseph C

    2010-01-01

    Embryonic stem (ES) cells have therapeutic potential in disorders of cellular loss such as myocardial infarction, type I diabetes and neurodegenerative disorders. ES cell biology in living subjects was largely poorly understood until incorporation of molecular imaging into the field. Reporter gene imaging works by integrating a reporter gene into ES cells and using a reporter probe to induce a signal detectable by normal imaging modalities. Reporter gene imaging allows for longitudinal tracking of ES cells within the same host for a prolonged period of time. This has advantages over postmortem immunohistochemistry and traditional imaging modalities. The advantages include expression of reporter gene is limited to viable cells, expression is conserved between generations of dividing cells, and expression can be linked to a specific population of cells. These advantages were especially useful in studying a dynamic cell population such as ES cells and proved useful in elucidating the biology of ES cells. Reporter gene imaging identified poor integration of differentiated ES cells transplanted into host tissue as well as delayed donor cell death as reasons for poor long-term survival in vivo. This imaging technology also confirmed that ES cells indeed have immunogenic properties that factor into cell survival and differentiation. Finally, reporter gene imaging improved our understanding of the neoplastic risk of undifferentiated ES cells in forming teratomas. Despite such advances, much remains to be understood about ES cell biology to translate this technology to the bedside, and reporter gene imaging will certainly play a key role in formulating this understanding.

  8. Tiny cells meet big questions: a closer look at bacterial cell biology.

    Science.gov (United States)

    Goley, Erin D

    2013-04-01

    While studying actin assembly as a graduate student with Matt Welch at the University of California at Berkeley, my interest was piqued by reports of surprising observations in bacteria: the identification of numerous cytoskeletal proteins, actin homologues fulfilling spindle-like functions, and even the presence of membrane-bound organelles. Curiosity about these phenomena drew me to Lucy Shapiro's lab at Stanford University for my postdoctoral research. In the Shapiro lab, and now in my lab at Johns Hopkins, I have focused on investigating the mechanisms of bacterial cytokinesis. Spending time as both a eukaryotic cell biologist and a bacterial cell biologist has convinced me that bacterial cells present the same questions as eukaryotic cells: How are chromosomes organized and accurately segregated? How is force generated for cytokinesis? How is polarity established? How are signals transduced within and between cells? These problems are conceptually similar between eukaryotes and bacteria, although their solutions can differ significantly in specifics. In this Perspective, I provide a broad view of cell biological phenomena in bacteria, the technical challenges facing those of us who peer into bacterial cells, and areas of common ground as research in eukaryotic and bacterial cell biology moves forward.

  9. Cell and molecular biology of epidermal growth factor receptor.

    Science.gov (United States)

    Ceresa, Brian P; Peterson, Joanne L

    2014-01-01

    The epidermal growth factor receptor (EGFR) has been one of the most intensely studied cell surface receptors due to its well-established roles in developmental biology, tissue homeostasis, and cancer biology. The EGFR has been critical for creating paradigms for numerous aspects of cell biology, such as ligand binding, signal transduction, and membrane trafficking. Despite this history of discovery, there is a continual stream of evidence that only the surface has been scratched. New ways of receptor regulation continue to be identified, each of which is a potential molecular target for manipulating EGFR signaling and the resultant changes in cell and tissue biology. This chapter is an update on EGFR-mediated signaling, and describes some recent developments in the regulation of receptor biology.

  10. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.|info:eu-repo/dai/nl/07493662X

    2005-01-01

    A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

  11. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.

    2005-01-01

    A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

  12. Applied Developmental Biology: Making Human Pancreatic Beta Cells for Diabetics.

    Science.gov (United States)

    Melton, Douglas A

    2016-01-01

    Understanding the genes and signaling pathways that determine the differentiation and fate of a cell is a central goal of developmental biology. Using that information to gain mastery over the fates of cells presents new approaches to cell transplantation and drug discovery for human diseases including diabetes. © 2016 Elsevier Inc. All rights reserved.

  13. 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.

  14. Numerical investigation of thermal response of laser-irradiated biological tissue phantoms embedded with gold nanoshells.

    Science.gov (United States)

    Phadnis, Akshay; Kumar, Sumit; Srivastava, Atul

    2016-10-01

    The work presented in this paper focuses on numerically investigating the thermal response of gold nanoshells-embedded biological tissue phantoms with potential applications into photo-thermal therapy wherein the interest is in destroying the cancerous cells with minimum damage to the surrounding healthy cells. The tissue phantom has been irradiated with a pico-second laser. Radiative transfer equation (RTE) has been employed to model the light-tissue interaction using discrete ordinate method (DOM). For determining the temperature distribution inside the tissue phantom, the RTE has been solved in combination with a generalized non-Fourier heat conduction model namely the dual phase lag bio-heat transfer model. The numerical code comprising the coupled RTE-bio-heat transfer equation, developed as a part of the current work, has been benchmarked against the experimental as well as the numerical results available in the literature. It has been demonstrated that the temperature of the optical inhomogeneity inside the biological tissue phantom embedded with gold nanoshells is relatively higher than that of the baseline case (no nanoshells) for the same laser power and operation time. The study clearly underlines the impact of nanoshell concentration and its size on the thermal response of the biological tissue sample. The comparative study concerned with the size and concentration of nanoshells showed that 60nm nanoshells with concentration of 5×10(15)mm(-3) result into the temperature levels that are optimum for the irreversible destruction of cancer infected cells in the context of photo-thermal therapy. To the best of the knowledge of the authors, the present study is one of the first attempts to quantify the influence of gold nanoshells on the temperature distributions inside the biological tissue phantoms upon laser irradiation using the dual phase lag heat conduction model.

  15. Chemistry and biology of the compounds that modulate cell migration.

    Science.gov (United States)

    Tashiro, Etsu; Imoto, Masaya

    2016-03-01

    Cell migration is a fundamental step for embryonic development, wound repair, immune responses, and tumor cell invasion and metastasis. Extensive studies have attempted to reveal the molecular mechanisms behind cell migration; however, they remain largely unclear. Bioactive compounds that modulate cell migration show promise as not only extremely powerful tools for studying the mechanisms behind cell migration but also as drug seeds for chemotherapy against tumor metastasis. Therefore, we have screened cell migration inhibitors and analyzed their mechanisms for the inhibition of cell migration. In this mini-review, we introduce our chemical and biological studies of three cell migration inhibitors: moverastin, UTKO1, and BU-4664L.

  16. Concise Review: Stem Cell Population Biology: Insights from Hematopoiesis.

    Science.gov (United States)

    MacLean, Adam L; Lo Celso, Cristina; Stumpf, Michael P H

    2017-01-01

    Stem cells are fundamental to human life and offer great therapeutic potential, yet their biology remains incompletely-or in cases even poorly-understood. The field of stem cell biology has grown substantially in recent years due to a combination of experimental and theoretical contributions: the experimental branch of this work provides data in an ever-increasing number of dimensions, while the theoretical branch seeks to determine suitable models of the fundamental stem cell processes that these data describe. The application of population dynamics to biology is amongst the oldest applications of mathematics to biology, and the population dynamics perspective continues to offer much today. Here we describe the impact that such a perspective has made in the field of stem cell biology. Using hematopoietic stem cells as our model system, we discuss the approaches that have been used to study their key properties, such as capacity for self-renewal, differentiation, and cell fate lineage choice. We will also discuss the relevance of population dynamics in models of stem cells and cancer, where competition naturally emerges as an influential factor on the temporal evolution of cell populations. Stem Cells 2017;35:80-88. © 2016 AlphaMed Press.

  17. Current view of mesenchymal stem cells biology (brief review

    Directory of Open Access Journals (Sweden)

    Maslova O. A.

    2012-06-01

    Full Text Available Although mesenchymal stem cells (MSC are in a focus of attention, some aspects of their biology are still unclear. This paper is a review of current research on MSC biology. The use of MSC in regenerative medicine is also briefly discussed.

  18. Evaluation of the Redesign of an Undergraduate Cell Biology Course

    Science.gov (United States)

    McEwen, Laura April; Harris, dik; Schmid, Richard F.; Vogel, Jackie; Western, Tamara; Harrison, Paul

    2009-01-01

    This article offers a case study of the evaluation of a redesigned and redeveloped laboratory-based cell biology course. The course was a compulsory element of the biology program, but the laboratory had become outdated and was inadequately equipped. With the support of a faculty-based teaching improvement project, the teaching team redesigned the…

  19. Evaluation of the Redesign of an Undergraduate Cell Biology Course

    Science.gov (United States)

    McEwen, Laura April; Harris, dik; Schmid, Richard F.; Vogel, Jackie; Western, Tamara; Harrison, Paul

    2009-01-01

    This article offers a case study of the evaluation of a redesigned and redeveloped laboratory-based cell biology course. The course was a compulsory element of the biology program, but the laboratory had become outdated and was inadequately equipped. With the support of a faculty-based teaching improvement project, the teaching team redesigned the…

  20. Cell Biology: Cohesin Rings Leave Loose Ends

    Science.gov (United States)

    Skibbens, Robert V.

    2016-01-01

    Cohesins function in almost all aspects of chromosome biology. Two new studies confirm that a subset of cohesin subunits form a flexible but compressed ring that can be opened through degradation. X-ray crystallography supports potentially differing regulation of subunit associations. PMID:25649818

  1. Bacterial cell biology outside the streetlight.

    Science.gov (United States)

    Bulgheresi, Silvia

    2016-09-01

    As much as vertical transmission of microbial symbionts requires their deep integration into the host reproductive and developmental biology, symbiotic lifestyle might profoundly affect bacterial growth and proliferation. This review describes the reproductive oddities displayed by bacteria associated - more or less intimately - with multicellular eukaryotes.

  2. An investigation into biological recognition coatings for piezoelectric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Sharron

    2002-07-01

    The concept of harvesting chemicals from nature and employing them with piezoelectric crystals for biosensor development is investigated. Literature is reviewed for information theory relating to molecular structure, biosensors, immobilisation techniques, piezoelectric transducers and biosensor applications of quartz crystals. Three types of molecules were investigated for their biosensing potential, saccharides (pectic acid and alginic acid), an enzyme (galactose oxidase) and an antibody (specific for Botrytis cinerea). Immobilisation procedures using {gamma}-aminopropyltrimethoxy silane, polyethyleneimine and glutaraldehyde cross-linking are developed for pectic acid, alginic acid, galactose oxidase and the Botrytis antibody. These materials are immobilised onto the gold electrode area of an AT-cut quartz crystal microbalance. Operating conditions, either dip and dry batch monitoring or dynamic real-time monitoring using a flow cell are outlined. Ageing of the piezoelectric crystal sensor through erosion of coatings or during physical cleaning of crystals, prior to recoating, is featured and is particularly important to future cost effective commercial piezoelectric crystal sensor systems. Scanning tunnel microscopy is selected and an example from literature is used to evidence possible mechanisms of primary coat bonding to the gold electrodes. The associated cleaning problems and explanation of memory effects are then postulated. Calibrating data with sensitivities and limits of detection are presented for Cu{sup 2+} (pectic acid coating, Cu{sup 2+} range of 0.002mM (0.128ppm) to 0.5mM (32ppm); galactose oxidase coating, Cu{sup 2+} range of 0.002mM (0.128ppm) to 0.5mM (32ppm)); and for Pb{sup 2+} (alginic acid coating, Pb{sup 2+} range of 0.002mM (0.414ppm) to 0.1mM (20.7ppm)). Interference effects of Pb, Co, Ni, Zn, Ca and Mg on Cu{sup 2+} detection and measurement are presented. Similarly interference effects of Cu, Co, Ni, Zn and Ca on Pb{sup 2+} detection

  3. Advances in Retinal Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Andrea S Viczian

    2013-01-01

    Full Text Available Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells.

  4. Probing bacterial cell biology using image cytometry.

    Science.gov (United States)

    Cass, Julie A; Stylianidou, Stella; Kuwada, Nathan J; Traxler, Beth; Wiggins, Paul A

    2017-03-01

    Advances in automated fluorescence microscopy have made snapshot and time-lapse imaging of bacterial cells commonplace, yet fundamental challenges remain in analysis. The vast quantity of data collected in high-throughput experiments requires a fast and reliable automated method to analyze fluorescence intensity and localization, cell morphology and proliferation as well as other descriptors. Inspired by effective yet tractable methods of population-level analysis using flow cytometry, we have developed a framework and tools for facilitating analogous analyses in image cytometry. These tools can both visualize and gate (generate subpopulations) more than 70 cell descriptors, including cell size, age and fluorescence. The method is well suited to multi-well imaging, analysis of bacterial cultures with high cell density (thousands of cells per frame) and complete cell cycle imaging. We give a brief description of the analysis of four distinct applications to emphasize the broad applicability of the tool.

  5. Cell biological analyses of anther morphogenesis and pollen viability in Arabidopsis and rice.

    Science.gov (United States)

    Chang, Fang; Zhang, Zaibao; Jin, Yue; Ma, Hong

    2014-01-01

    Major advances have been made in recent years in our understanding of anther development through a combination of genetic studies, cell biological technologies, biochemical analysis, microarray and high-throughput sequencing-based approaches. In this chapter, we summarize the widely used protocols for pollen viability staining; the investigation of anther morphogenesis by light microscopy of semi-thin sections; TUNEL assay for programmed tapetum cell death; and laser microdissection procedures to obtain specialized cells or cell layers for carrying out transcriptomics.

  6. The Cell Biology of Fission Yeast Septation.

    Science.gov (United States)

    García Cortés, Juan C; Ramos, Mariona; Osumi, Masako; Pérez, Pilar; Ribas, Juan Carlos

    2016-09-01

    In animal cells, cytokinesis requires the formation of a cleavage furrow that divides the cell into two daughter cells. Furrow formation is achieved by constriction of an actomyosin ring that invaginates the plasma membrane. However, fungal cells contain a rigid extracellular cell wall surrounding the plasma membrane; thus, fungal cytokinesis also requires the formation of a special septum wall structure between the dividing cells. The septum biosynthesis must be strictly coordinated with the deposition of new plasma membrane material and actomyosin ring closure and must occur in such a way that no breach in the cell wall occurs at any time. Because of the high turgor pressure in the fungal cell, even a minor local defect might lead to cell lysis and death. Here we review our knowledge of the septum structure in the fission yeast Schizosaccharomyces pombe and of the recent advances in our understanding of the relationship between septum biosynthesis and actomyosin ring constriction and how the two collaborate to build a cross-walled septum able to support the high turgor pressure of the cell. In addition, we discuss the importance of the septum biosynthesis for the steady ingression of the cleavage furrow.

  7. Cell Division and Evolution of Biological Tissues

    Science.gov (United States)

    Rivier, Nicolas; Arcenegui-Siemens, Xavier; Schliecker, Gudrun

    A tissue is a geometrical, space-filling, random cellular network; it remains in this steady state while individual cells divide. Cell division (fragmentation) is a local, elementary topological transformation which establishes statistical equilibrium of the structure. Statistical equilibrium is characterized by observable relations (Lewis, Aboav) between cell shapes, sizes and those of their neighbours, obtained through maximum entropy and topological correlation extending to nearest neighbours only, i.e. maximal randomness. For a two-dimensional tissue (epithelium), the distribution of cell shapes and that of mother and daughter cells can be obtained from elementary geometrical and physical arguments, except for an exponential factor favouring division of larger cells, and exponential and combinatorial factors encouraging a most symmetric division. The resulting distributions are very narrow, and stationarity severely restricts the range of an adjustable structural parameter

  8. Investigation of Biological Soil Crusts Metabolic Webs Using Exometabolomic Analysis

    Science.gov (United States)

    Northen, T.; Karaoz, U.; Jenkins, S.; Lau, R.; Bowen, B.; Cadillo-Quiroz, H.; Garcia-Pichel, F.; Brodie, E.; Richard, B.

    2014-12-01

    Desert biological soil crusts are simple cyanobacteria-dominated surface soil microbial communities found in areas with infrequent wetting, often extreme temperatures, low coverage of vascular plants and constitute the world's largest biofilm. They exist for extended periods in a desiccated dormant state, yet rapidly re-boot metabolism within minutes of wetting. These soil microbial communities are highly dependent on filamentous cyanobacteria such as Microcoleus vaginatusto stabilize the soil and to act as primary producers for the community through the release carbon sources to feed a diversity of heterotrophs. Exometabolomic analysis was performed using liquid chromatography coupled to tandem mass spectrometry on biological soil crust pore water and spent media of key soil bacterial isolates. Comparison of spent vs. fresh media was used to determine uptake or release of metabolites by specific microbes. To link pore water experiments with isolate studies, metabolite extracts of authentic soil were used as supplements for isolate exometabolomic profiling. Our soil metabolomics methods detected hundreds of metabolites from soils including may novel compounds. Only a small set of which being targeted by all isolates. Beyond these few metabolites, the individual bacteria examined showed specialization towards specific metabolites. Surprisingly, many of the most abundant oligosaccharides and other metabolites were ignored by these isolates. The observed specialization of biological soil crust bacteria may play a significant role in determining community structure.

  9. Stem cell biology and drug discovery

    Directory of Open Access Journals (Sweden)

    Haston Kelly M

    2011-06-01

    Full Text Available Abstract There are many reasons to be interested in stem cells, one of the most prominent being their potential use in finding better drugs to treat human disease. This article focuses on how this may be implemented. Recent advances in the production of reprogrammed adult cells and their regulated differentiation to disease-relevant cells are presented, and diseases that have been modeled using these methods are discussed. Remaining difficulties are highlighted, as are new therapeutic insights that have emerged.

  10. Biology at a single cell level

    CSIR Research Space (South Africa)

    Mthunzi, P

    2012-10-01

    Full Text Available brain ? Non- renewing cell type ? Neurons difficult to transfect with established protocols ? Susceptible to degenerative disorders: - Parkinson?s disease - Multiple sclerosis - Alzheimer's disease http...

  11. Biological effects of Echinacea purpurea on human blood cells.

    Science.gov (United States)

    Joksić, Gordana; Petrović, Sandra; Joksić, Ivana; Leskovac, Andreja

    2009-06-01

    The aim of this study was to investigate radioprotective properties of Echinacea purpurea tablets in vivo. We analysed lymphocyte chromosome aberrations (CA), micronuclei (MN), apoptosis of leukocytes and haematological parameters in a group of radiation workers who were identified as carrying dicentric chromosomes in their lymphocytes. All radiation workers were taking two 275 mg Echinacea tablets b.i.d., according to a pharmacist's recommendation. All parameters were analysed before and after the two-week treatment. At the end of the treatment lymphocyte CA frequency dropped significantly, and the number of apoptotic cells increased. The inverse lymphocyte-to-granulocyte ratio at the beginning of the study changed to normal at its end. In conclusion, biological effects observed after administration of Echinacea purpurea preparation suggest that it may be beneficial for the prevention of adverse health effects in workers exposed to ionising radiation.

  12. Extension of dynamics of granular flow methodology to cell biology

    Science.gov (United States)

    Kummer, A.; Ocone, R.

    2003-04-01

    In a previous paper (J. Non-Newtonian Fluid Mech. 76 (1998) 5), the analogy between the methodology typical of the dynamics of polymeric liquids and those used in granular flow theory was investigated. It was shown that such a methodology could be successfully extended to granular flow, and then it was speculated on the possibility of extending it to diverse areas. In this paper two important conclusions are reached. Firstly we show that the methodology behind the statistical theories (which starting from the microstructural element eventually leads to the formulation of constitutive equations (AICHE Symposium Series, Vol. 93, 1997, p. 103)) can be extended to an apparently completely different field, namely cell biology. We then show that classical thermodynamics, as applied to epigenetic systems, presents limitations which can be overcome following an axiomatic thermodynamic route (J. Rheol. 37 (1993) 727).

  13. Glial cell biology in the Great Lakes region.

    Science.gov (United States)

    Feinstein, Douglas L; Skoff, Robert P

    2016-03-31

    We report on the tenth bi-annual Great Lakes Glial meeting, held in Traverse City, Michigan, USA, September 27-29 2015. The GLG meeting is a small conference that focuses on current research in glial cell biology. The array of functions that glial cells (astrocytes, microglia, oligodendrocytes, Schwann cells) play in health and disease is constantly increasing. Despite this diversity, GLG meetings bring together scientists with common interests, leading to a better understanding of these cells. This year's meeting included two keynote speakers who presented talks on the regulation of CNS myelination and the consequences of stress on Schwann cell biology. Twenty-two other talks were presented along with two poster sessions. Sessions covered recent findings in the areas of microglial and astrocyte activation; age-dependent changes to glial cells, Schwann cell development and pathology, and the role of stem cells in glioma and neural regeneration.

  14. Interdisciplinary Team Science in Cell Biology.

    Science.gov (United States)

    Horwitz, Rick

    2016-11-01

    The cell is complex. With its multitude of components, spatial-temporal character, and gene expression diversity, it is challenging to comprehend the cell as an integrated system and to develop models that predict its behaviors. I suggest an approach to address this issue, involving system level data analysis, large scale team science, and philanthropy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Translating Stem Cell Biology Into Drug Discovery

    Science.gov (United States)

    Singeç, Ilyas; Simeonov, Anton

    2016-01-01

    Pluripotent stem cell research has made extraordinary progress over the last decade. The robustness of nuclear reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) has created entirely novel opportunities for drug discovery and personalized regenerative medicine. Patient- and disease-specific iPSCs can be expanded indefinitely and differentiated into relevant cell types of different organ systems. As the utilization of iPSCs is becoming a key enabling technology across various scientific disciplines, there are still important challenges that need to be addressed. Here we review the current state and reflect on the issues that the stem cell and translational communities are facing in bringing iPSCs closer to clinical application.

  16. Towards understanding cellular structure biology: In-cell NMR.

    Science.gov (United States)

    Rahman, Safikur; Byun, Younhwa; Hassan, Md Imtaiyaz; Kim, Jihoe; Kumar, Vijay

    2017-05-01

    To watch biological macromolecules perform their functions inside the living cells is the dream of any biologists. In-cell nuclear magnetic resonance is a branch of biomolecular NMR spectroscopy that can be used to observe the structures, interactions and dynamics of these molecules in the living cells at atomic level. In principle, in-cell NMR can be applied to different cellular systems to achieve biologically relevant structural and functional information. In this review, we summarize the existing approaches in this field and discuss its applications in protein interactions, folding, stability and post-translational modifications. We hope this review will emphasize the effectiveness of in-cell NMR for studies of intricate biological processes and for structural analysis in cellular environments. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Micro/nano-fabrication technologies for cell biology.

    Science.gov (United States)

    Qian, Tongcheng; Wang, Yingxiao

    2010-10-01

    Micro/nano-fabrication techniques, such as soft lithography and electrospinning, have been well-developed and widely applied in many research fields in the past decade. Due to the low costs and simple procedures, these techniques have become important and popular for biological studies. In this review, we focus on the studies integrating micro/nano-fabrication work to elucidate the molecular mechanism of signaling transduction in cell biology. We first describe different micro/nano-fabrication technologies, including techniques generating three-dimensional scaffolds for tissue engineering. We then introduce the application of these technologies in manipulating the physical or chemical micro/nano-environment to regulate the cellular behavior and response, such as cell life and death, differentiation, proliferation, and cell migration. Recent advancement in integrating the micro/nano-technologies and live cell imaging are also discussed. Finally, potential schemes in cell biology involving micro/nano-fabrication technologies are proposed to provide perspectives on the future research activities.

  18. Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

    Science.gov (United States)

    Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

    2015-01-01

    In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

  19. Peroxisystem: harnessing systems cell biology to study peroxisomes.

    Science.gov (United States)

    Schuldiner, Maya; Zalckvar, Einat

    2015-04-01

    In recent years, high-throughput experimentation with quantitative analysis and modelling of cells, recently dubbed systems cell biology, has been harnessed to study the organisation and dynamics of simple biological systems. Here, we suggest that the peroxisome, a fascinating dynamic organelle, can be used as a good candidate for studying a complete biological system. We discuss several aspects of peroxisomes that can be studied using high-throughput systematic approaches and be integrated into a predictive model. Such approaches can be used in the future to study and understand how a more complex biological system, like a cell and maybe even ultimately a whole organism, works. © 2015 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  20. Quantitative stem cell biology: the threat and the glory.

    Science.gov (United States)

    Pollard, Steven M

    2016-11-15

    Major technological innovations over the past decade have transformed our ability to extract quantitative data from biological systems at an unprecedented scale and resolution. These quantitative methods and associated large datasets should lead to an exciting new phase of discovery across many areas of biology. However, there is a clear threat: will we drown in these rivers of data? On 18th July 2016, stem cell biologists gathered in Cambridge for the 5th annual Cambridge Stem Cell Symposium to discuss 'Quantitative stem cell biology: from molecules to models'. This Meeting Review provides a summary of the data presented by each speaker, with a focus on quantitative techniques and the new biological insights that are emerging. © 2016. Published by The Company of Biologists Ltd.

  1. Mechanistic modeling confronts the complexity of molecular cell biology.

    Science.gov (United States)

    Phair, Robert D

    2014-11-05

    Mechanistic modeling has the potential to transform how cell biologists contend with the inescapable complexity of modern biology. I am a physiologist-electrical engineer-systems biologist who has been working at the level of cell biology for the past 24 years. This perspective aims 1) to convey why we build models, 2) to enumerate the major approaches to modeling and their philosophical differences, 3) to address some recurrent concerns raised by experimentalists, and then 4) to imagine a future in which teams of experimentalists and modelers build-and subject to exhaustive experimental tests-models covering the entire spectrum from molecular cell biology to human pathophysiology. There is, in my view, no technical obstacle to this future, but it will require some plasticity in the biological research mind-set.

  2. Cell-free biology: exploiting the interface between synthetic biology and synthetic chemistry.

    Science.gov (United States)

    Harris, D Calvin; Jewett, Michael C

    2012-10-01

    Just as synthetic organic chemistry once revolutionized the ability of chemists to build molecules (including those that did not exist in nature) following a basic set of design rules, cell-free synthetic biology is beginning to provide an improved toolbox and faster process for not only harnessing but also expanding the chemistry of life. At the interface between chemistry and biology, research in cell-free synthetic systems is proceeding in two different directions: using synthetic biology for synthetic chemistry and using synthetic chemistry to reprogram or mimic biology. In the coming years, the impact of advances inspired by these approaches will make possible the synthesis of nonbiological polymers having new backbone compositions, new chemical properties, new structures, and new functions.

  3. Stochasticity in cell biology: Modeling across levels

    Science.gov (United States)

    Pedraza, Juan Manuel

    2009-03-01

    Effective modeling of biological processes requires focusing on a particular level of description, and this requires summarizing de details of lower levels into effective variables and properly accounting for the constrains that other levels impose. In the context of stochasticity in gene expression, I will show how the details of the stochastic process can be characterized by a few effective parameters, which facilitates modeling but complicates interpretation of current experiments. I will show how the resulting noise can provide advantageous or deleterious phenotypic fluctuation and how noise control in the copy number control system of plasmids can change the selective pressures. This system illustrates the direct connection between molecular dynamics and evolutionary dynamics.

  4. Cultivation and Biological Characterization of Chicken Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Meng Ji

    2016-01-01

    Full Text Available The purpose of this work was to investigate the isolation, culture process of chicken gonadal primordial germ cells (PGCs and study their biological characterization. PGCs were harvested from 5.5-day-old chicken embryonic genital ridges and explanted onto chicken embryonic fibroblasts (CEFs. The results showed that the primary cultivation of chicken PGCs on their own gonadal stroma cells were better than CEFs at first two days for reproduction. The conditioned media supported the growth and colony formation of PGCs for a prolonged time in vitro and maintained a normal diploid karyotype, which were positively stained by alkaline phosphatase (AKP, periodic acid Schiff (PAS and reacted with anti-SSEA-1, SSEA-3, Oct4, Blimp1 and Sox2. Real-time PCR showed that they expressed the stage specific genes CVH, Blimp1 and Dazl, the stem cell specific genes Sox2, Pouv and Nanog. They also formed the embryoid bodies (EBs. These results suggested that the chicken PGCs cultured in vitro not only had strong self-renewal ability, but also had the potential capability of multi-lineage differentiation.

  5. Manipulation of biological cells with a microelectromagnet matrix

    Science.gov (United States)

    Lee, Hakho; Hunt, Tom P.; Westervelt, Robert M.

    2004-03-01

    Microscopic manipulation of biological cells was demonstrated with a microelectromagnet matrix. The matrix has two layers of straight Au wires, aligned perpendicular to each other, that are covered with insulating layers [1]. Strong and localized magnetic fields by the matrix allow the stable micromanipulation of magnetically tagged biological cells in a fluid. Moreover, by adjusting current in each wire, a microelectromagnet matrix can create versatile magnetic field patterns for the independent and simultaneous manipulation of multiple cells. In this talk, we present the manipulation of magnetically tagged yeast cells in micron length scales with a matrix. Single or multiple cells were trapped, continuously moved and rotated in a fluid; a viable cell was separated from nonviable ones and was independently moved for cell sorting. [1] C.S. Lee, H. Lee and R.M. Westervelt, Appl. Phys. Lett. 79, 3308 (2001)

  6. Neural crest cells: from developmental biology to clinical interventions.

    Science.gov (United States)

    Noisa, Parinya; Raivio, Taneli

    2014-09-01

    Neural crest cells are multipotent cells, which are specified in embryonic ectoderm in the border of neural plate and epiderm during early development by interconnection of extrinsic stimuli and intrinsic factors. Neural crest cells are capable of differentiating into various somatic cell types, including melanocytes, craniofacial cartilage and bone, smooth muscle, and peripheral nervous cells, which supports their promise for cell therapy. In this work, we provide a comprehensive review of wide aspects of neural crest cells from their developmental biology to applicability in medical research. We provide a simplified model of neural crest cell development and highlight the key external stimuli and intrinsic regulators that determine the neural crest cell fate. Defects of neural crest cell development leading to several human disorders are also mentioned, with the emphasis of using human induced pluripotent stem cells to model neurocristopathic syndromes. © 2014 Wiley Periodicals, Inc.

  7. Molecular biology of cantharidin in cancer cells.

    Science.gov (United States)

    Rauh, Rolf; Kahl, Stefan; Boechzelt, Herbert; Bauer, Rudolf; Kaina, Bernd; Efferth, Thomas

    2007-07-04

    Herbal medicine is one of the forms of traditional medical practice. Traditional Chinese medicine (TCM) and traditional Vietnamese medicine (TVM) are well-known for their long-standing tradition of herbal medicine. Secreted by many species of blister beetle, most notably by the 'Spanish fly' (Lytta vesicatoria), cantharidin inhibits protein phosphatases 1 and 2A (PP1, PP2A). Blister beetle has been used in Asian traditional medicine to treat Molluscum contagiosum virus (MCV) infections and associated warts, and is now also used for cancer treatment. A combination of both genomic and postgenomic techniques was used in our studies to identify candidate genes affecting sensitivity or resistance to cantharidin. Cantharidin was not found to be related to multidrug resistance phenotype, suggesting its potential usefulness for the treatment of refractory tumors. Oxidative stress response genes diminish the activity of cantharidin by inducing DNA strand breaks which may be subject to base excision repair and induce apoptosis in a p53- and Bcl2-dependent manner. Cantharidin is one of many natural products used in traditional Chinese medicine and traditional Vietnamese medicine for cancer treatment. Combined methods of pharmaceutical biology and molecular biology can help elucidate modes of action of these natural products.

  8. Molecular biology of cantharidin in cancer cells

    Directory of Open Access Journals (Sweden)

    Bauer Rudolf

    2007-07-01

    Full Text Available Abstract Herbal medicine is one of the forms of traditional medical practice. Traditional Chinese medicine (TCM and traditional Vietnamese medicine (TVM are well-known for their long-standing tradition of herbal medicine. Secreted by many species of blister beetle, most notably by the 'Spanish fly' (Lytta vesicatoria, cantharidin inhibits protein phosphatases 1 and 2A (PP1, PP2A. Blister beetle has been used in Asian traditional medicine to treat Molluscum contagiosum virus (MCV infections and associated warts, and is now also used for cancer treatment. A combination of both genomic and postgenomic techniques was used in our studies to identify candidate genes affecting sensitivity or resistance to cantharidin. Cantharidin was not found to be related to multidrug resistance phenotype, suggesting its potential usefulness for the treatment of refractory tumors. Oxidative stress response genes diminish the activity of cantharidin by inducing DNA strand breaks which may be subject to base excision repair and induce apoptosis in a p53- and Bcl2-dependent manner. Cantharidin is one of many natural products used in traditional Chinese medicine and traditional Vietnamese medicine for cancer treatment. Combined methods of pharmaceutical biology and molecular biology can help elucidate modes of action of these natural products.

  9. Evolutionary cell biology: functional insight from "endless forms most beautiful".

    Science.gov (United States)

    Richardson, Elisabeth; Zerr, Kelly; Tsaousis, Anastasios; Dorrell, Richard G; Dacks, Joel B

    2015-12-15

    In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking. © 2015 Richardson et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  10. Microfluidics meet cell biology: bridging the gap by validation and application of microscale techniques for cell biological assays.

    Science.gov (United States)

    Paguirigan, Amy L; Beebe, David J

    2008-09-01

    Microscale techniques have been applied to biological assays for nearly two decades, but haven't been widely integrated as common tools in biological laboratories. The significant differences between several physical phenomena at the microscale versus the macroscale have been exploited to provide a variety of new types of assays (such as gradient production or spatial cell patterning). However, the use of these devices by biologists seems to be limited by issues regarding biological validation, ease of use, and the limited available readouts for assays done using microtechnology. Critical validation work has been done recently that highlights the current challenges for microfluidic methods and suggest ways in which future devices might be improved to better integrate with biological assays. With more validation and improved designs, microscale techniques hold immense promise as a platform to study aspects of cell biology that are not possible using current macroscale techniques.

  11. 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.

  12. Manipulation of biological cells using a microelectromagnet matrix

    Science.gov (United States)

    Lee, H.; Purdon, A. M.; Westervelt, R. M.

    2004-08-01

    Noninvasive manipulation of biological cells inside a microfluidic channel was demonstrated using a microelectromagnet matrix. The matrix consists of two layers of straight Au wires, aligned perpendicular to each other, that are covered by insulating layers. By adjusting the current in each independent wire, the microelectromagnet matrix can create versatile magnetic field patterns to control the motion of individual cells in fluid. Single or multiple yeast cells attached to magnetic beads were trapped, continuously moved and rotated, and a viable cell was separated from nonviable cells for cell sorting.

  13. Bioinformatics approaches to single-cell analysis in developmental biology.

    Science.gov (United States)

    Yalcin, Dicle; Hakguder, Zeynep M; Otu, Hasan H

    2016-03-01

    Individual cells within the same population show various degrees of heterogeneity, which may be better handled with single-cell analysis to address biological and clinical questions. Single-cell analysis is especially important in developmental biology as subtle spatial and temporal differences in cells have significant associations with cell fate decisions during differentiation and with the description of a particular state of a cell exhibiting an aberrant phenotype. Biotechnological advances, especially in the area of microfluidics, have led to a robust, massively parallel and multi-dimensional capturing, sorting, and lysis of single-cells and amplification of related macromolecules, which have enabled the use of imaging and omics techniques on single cells. There have been improvements in computational single-cell image analysis in developmental biology regarding feature extraction, segmentation, image enhancement and machine learning, handling limitations of optical resolution to gain new perspectives from the raw microscopy images. Omics approaches, such as transcriptomics, genomics and epigenomics, targeting gene and small RNA expression, single nucleotide and structural variations and methylation and histone modifications, rely heavily on high-throughput sequencing technologies. Although there are well-established bioinformatics methods for analysis of sequence data, there are limited bioinformatics approaches which address experimental design, sample size considerations, amplification bias, normalization, differential expression, coverage, clustering and classification issues, specifically applied at the single-cell level. In this review, we summarize biological and technological advancements, discuss challenges faced in the aforementioned data acquisition and analysis issues and present future prospects for application of single-cell analyses to developmental biology. © The Author 2015. Published by Oxford University Press on behalf of the European

  14. The shifting geography and language of cell biology.

    Science.gov (United States)

    Mayor, Satyajit

    2015-05-11

    With the increase in scientific activity globally, the geographical focus of basic research is shifting away from the West. At the same time, multidisciplinary approaches are uncovering new layers in our understanding of how cells work. How will these trends affect cell biology in the near future?

  15. Investigation on inhibition of biological effects of endothelin

    Institute of Scientific and Technical Information of China (English)

    田青; 赵东; 张继峰; 高连如; 刘胜昔; 杨军; 苏静怡; 张肇康; 汤健; 唐朝枢

    1996-01-01

    The effects of a series of substances on the biological function of endothelin (ET) are reported. The substances used are: synthetic inhibitors of endothelium derived relaxing factors (EDRFs), inhibitor of big-endothelin converting enzyme phosphoramidon, antiserum of endothelin, antagonists of endothelin A receptor BQ123 and JKC301, and two Chinese anti-snake venom herb medicines Lobelia radians Thumb and Taris polyphylla Smith var. chinensis (Franch) Hara. The results showed that inhibiting the production of nitric oxide (NO) could stimulate ET release from vascular endothelium, elevate plasma ET and increase blood pressure. These changes could be reversed by L-arginine (L-Arg), the substrate of nitric oxide synthase (NOS). The amount of ET released by arterial endothelium could be increased or inhibited by inhibiting or stimulating the synthesis of prostacyclin (PGI2). The plasma ET level and blood pressure in both SHR and WKY rats could be decreased by giving phosphoramidon (PhR). The above results i

  16. Fundamental Investigations of the Tribological Properties of Biological Interfaces

    Science.gov (United States)

    2007-11-28

    press) 4 therapy and drug-delivery applications, and had used a slightly different synthetic approach and starting reagents to us. The materials...cleaned by UV/ ozone cleaner (Boeckel industries Inc., model 135500) for 30 min. The cleaned waveguides were assembled into the OWLS flow cell and

  17. Shedding light on biology of bacterial cells.

    Science.gov (United States)

    Schneider, Johannes P; Basler, Marek

    2016-11-05

    To understand basic principles of living organisms one has to know many different properties of all cellular components, their mutual interactions but also their amounts and spatial organization. Live-cell imaging is one possible approach to obtain such data. To get multiple snapshots of a cellular process, the imaging approach has to be gentle enough to not disrupt basic functions of the cell but also have high temporal and spatial resolution to detect and describe the changes. Light microscopy has become a method of choice and since its early development over 300 years ago revolutionized our understanding of living organisms. As most cellular components are indistinguishable from the rest of the cellular contents, the second revolution came from a discovery of specific labelling techniques, such as fusions to fluorescent proteins that allowed specific tracking of a component of interest. Currently, several different tags can be tracked independently and this allows us to simultaneously monitor the dynamics of several cellular components and from the correlation of their dynamics to infer their respective functions. It is, therefore, not surprising that live-cell fluorescence microscopy significantly advanced our understanding of basic cellular processes. Current cameras are fast enough to detect changes with millisecond time resolution and are sensitive enough to detect even a few photons per pixel. Together with constant improvement of properties of fluorescent tags, it is now possible to track single molecules in living cells over an extended period of time with a great temporal resolution. The parallel development of new illumination and detection techniques allowed breaking the diffraction barrier and thus further pushed the resolution limit of light microscopy. In this review, we would like to cover recent advances in live-cell imaging technology relevant to bacterial cells and provide a few examples of research that has been possible due to imaging

  18. Shedding light on biology of bacterial cells

    Science.gov (United States)

    2016-01-01

    To understand basic principles of living organisms one has to know many different properties of all cellular components, their mutual interactions but also their amounts and spatial organization. Live-cell imaging is one possible approach to obtain such data. To get multiple snapshots of a cellular process, the imaging approach has to be gentle enough to not disrupt basic functions of the cell but also have high temporal and spatial resolution to detect and describe the changes. Light microscopy has become a method of choice and since its early development over 300 years ago revolutionized our understanding of living organisms. As most cellular components are indistinguishable from the rest of the cellular contents, the second revolution came from a discovery of specific labelling techniques, such as fusions to fluorescent proteins that allowed specific tracking of a component of interest. Currently, several different tags can be tracked independently and this allows us to simultaneously monitor the dynamics of several cellular components and from the correlation of their dynamics to infer their respective functions. It is, therefore, not surprising that live-cell fluorescence microscopy significantly advanced our understanding of basic cellular processes. Current cameras are fast enough to detect changes with millisecond time resolution and are sensitive enough to detect even a few photons per pixel. Together with constant improvement of properties of fluorescent tags, it is now possible to track single molecules in living cells over an extended period of time with a great temporal resolution. The parallel development of new illumination and detection techniques allowed breaking the diffraction barrier and thus further pushed the resolution limit of light microscopy. In this review, we would like to cover recent advances in live-cell imaging technology relevant to bacterial cells and provide a few examples of research that has been possible due to imaging. This

  19. The circadian clock and cell cycle: interconnected biological circuits.

    Science.gov (United States)

    Masri, Selma; Cervantes, Marlene; Sassone-Corsi, Paolo

    2013-12-01

    The circadian clock governs biological timekeeping on a systemic level, helping to regulate and maintain physiological processes, including endocrine and metabolic pathways with a periodicity of 24-hours. Disruption within the circadian clock machinery has been linked to numerous pathological conditions, including cancer, suggesting that clock-dependent regulation of the cell cycle is an essential control mechanism. This review will highlight recent advances on the 'gating' controls of the circadian clock at various checkpoints of the cell cycle and also how the cell cycle can influence biological rhythms. The reciprocal influence that the circadian clock and cell cycle exert on each other suggests that these intertwined biological circuits are essential and multiple regulatory/control steps have been instated to ensure proper timekeeping.

  20. The cell biology of TRIM5α.

    Science.gov (United States)

    Lukic, Zana; Campbell, Edward M

    2012-03-01

    The tripartite motif (TRIM)-containing proteins are involved in many cellular functions such as cell signaling, apoptosis, cell differentiation, and immune modulation. TRIM5 proteins, including TRIM5α and TRIM-Cyp, are known to possess antiretroviral activity against many different retroviruses. Besides being retroviral restriction factors, TRIM5 proteins participate in other cellular functions that have recently emerged in the study of TRIM5α. In this review, we discuss properties of TRIM5α such as cytoplasmic body formation, protein turnover, and trafficking. Also, we discuss recent insights into innate immune modulation mediated by TRIM5α, highlighting the various functions TRIM5α has in cellular processes.

  1. Muscle Satellite Cells: Exploring the Basic Biology to Rule Them.

    Science.gov (United States)

    Almeida, Camila F; Fernandes, Stephanie A; Ribeiro Junior, Antonio F; Keith Okamoto, Oswaldo; Vainzof, Mariz

    2016-01-01

    Adult skeletal muscle is a postmitotic tissue with an enormous capacity to regenerate upon injury. This is accomplished by resident stem cells, named satellite cells, which were identified more than 50 years ago. Since their discovery, many researchers have been concentrating efforts to answer questions about their origin and role in muscle development, the way they contribute to muscle regeneration, and their potential to cell-based therapies. Satellite cells are maintained in a quiescent state and upon requirement are activated, proliferating, and fusing with other cells to form or repair myofibers. In addition, they are able to self-renew and replenish the stem pool. Every phase of satellite cell activity is highly regulated and orchestrated by many molecules and signaling pathways; the elucidation of players and mechanisms involved in satellite cell biology is of extreme importance, being the first step to expose the crucial points that could be modulated to extract the optimal response from these cells in therapeutic strategies. Here, we review the basic aspects about satellite cells biology and briefly discuss recent findings about therapeutic attempts, trying to raise questions about how basic biology could provide a solid scaffold to more successful use of these cells in clinics.

  2. Synthetic biology of cyanobacterial cell factories

    NARCIS (Netherlands)

    Angermayr, S.A.

    2014-01-01

    In the field of microbial biotechnology rational design approaches are employed for the generation of microbial cells with desired functions, such as the ability to produce precursor molecules for biofuels or bioplastics. In essence, that is the introduction of a (new) biosynthetic pathway into a mi

  3. Cell Biology: ERADicating Survival with BOK.

    Science.gov (United States)

    Chipuk, Jerry Edward; Luna-Vargas, Mark P

    2016-06-01

    Mechanistic insights into the function of the pro-apoptotic BCL-2 family member BOK have remained elusive. A recent study shows that healthy cells constitutively degrade BOK via the ER-associated degradation and ubiquitin-proteasome pathways; following proteasome inhibition, BOK is stabilized to initiate a unique pro-apoptotic death program.

  4. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  5. Cell Culture in Microgravity: Opening the Door to Space Cell Biology

    Science.gov (United States)

    Pellis, Neal R.; Dawson, David L. (Technical Monitor)

    1999-01-01

    Adaptational response of human cell populations to microgravity is investigated using simulation, short-term Shuttle experiments, and long-term microgravity. Simulation consists of a clinostatically-rotated cell culture system. The system is a horizontally-rotated cylinder completely filled with culture medium. Low speed rotation results in continuous-fall of the cells through the fluid medium. In this setting, cells: 1) aggregate, 2) propagate in three dimensions, 3) synthesize matrix, 4) differentiate, and 5) form sinusoids that facilitate mass transfer. Space cell culture is conducted in flight bioreactors and in static incubators. Cells grown in microgravity are: bovine cartilage, promyelocytic leukemia, kidney proximal tubule cells, adrenal medulla, breast and colon cancer, and endothelium. Cells were cultured in space to test specific hypotheses. Cartilage cells were used to determine structural differences in cartilage grown in space compared to ground-based bioreactors. Results from a 130-day experiment on Mir revealed that cartilage grown in space was substantially more compressible due to insufficient glycosaminoglycan in the matrix. Interestingly, earth-grown cartilage conformed better to the dimensions of the scaffolding material, while the Mir specimens were spherical. The other cell populations are currently being analyzed for cell surface properties, gene expression, and differentiation. Results suggest that some cells spontaneously differentiate in microgravity. Additionally, vast changes in gene expression may occur in response to microgravity. In conclusion, the transition to microgravity may constitute a physical perturbation in cells resulting in unique gene expressions, the consequences of which may be useful in tissue engineering, disease modeling, and space cell biology.

  6. Cell Culture in Microgravity: Opening the Door to Space Cell Biology

    Science.gov (United States)

    Pellis, Neal R.; Dawson, David L. (Technical Monitor)

    1999-01-01

    Adaptational response of human cell populations to microgravity is investigated using simulation, short-term Shuttle experiments, and long-term microgravity. Simulation consists of a clinostatically-rotated cell culture system. The system is a horizontally-rotated cylinder completely filled with culture medium. Low speed rotation results in continuous-fall of the cells through the fluid medium. In this setting, cells: 1) aggregate, 2) propagate in three dimensions, 3) synthesize matrix, 4) differentiate, and 5) form sinusoids that facilitate mass transfer. Space cell culture is conducted in flight bioreactors and in static incubators. Cells grown in microgravity are: bovine cartilage, promyelocytic leukemia, kidney proximal tubule cells, adrenal medulla, breast and colon cancer, and endothelium. Cells were cultured in space to test specific hypotheses. Cartilage cells were used to determine structural differences in cartilage grown in space compared to ground-based bioreactors. Results from a 130-day experiment on Mir revealed that cartilage grown in space was substantially more compressible due to insufficient glycosaminoglycan in the matrix. Interestingly, earth-grown cartilage conformed better to the dimensions of the scaffolding material, while the Mir specimens were spherical. The other cell populations are currently being analyzed for cell surface properties, gene expression, and differentiation. Results suggest that some cells spontaneously differentiate in microgravity. Additionally, vast changes in gene expression may occur in response to microgravity. In conclusion, the transition to microgravity may constitute a physical perturbation in cells resulting in unique gene expressions, the consequences of which may be useful in tissue engineering, disease modeling, and space cell biology.

  7. Biology and physics of cell shape changes in development.

    Science.gov (United States)

    Paluch, Ewa; Heisenberg, Carl-Philipp

    2009-09-15

    Together with cell growth, division and death, changes in cell shape are of central importance for tissue morphogenesis during development. Cell shape is the product of a cell's material and active properties balanced by external forces. Control of cell shape, therefore, relies on both tight regulation of intracellular mechanics and the cell's physical interaction with its environment. In this review, we first discuss the biological and physical mechanisms of cell shape control. We next examine a number of developmental processes in which cell shape change - either individually or in a coordinated manner - drives embryonic morphogenesis and discuss how cell shape is controlled in these processes. Finally, we emphasize that cell shape control during tissue morphogenesis can only be fully understood by using a combination of cellular, molecular, developmental and biophysical approaches.

  8. Investigation of CNTs interaction with fibroblast cells.

    Science.gov (United States)

    Pensabene, V; Vittorio, O; Raffa, V; Menciassi, A; Dario, P

    2007-01-01

    The need for toxicological studies on carbon nanotubes (CNTs) has arisen from the rapidly emerging applications of CNTs well beyond material science and engineering. In order to provide a method to collect data about toxicology, we characterized by Scanning Electron Microscopy (SEM), by Energy Dispersive X-ray Spectrometry (EDS) analysis and by Focused Ion Beam (FIB) microscopy different kinds of treated CNTs. The bio-interaction was investigated seeding Crandell feline kidney fibroblasts with CNT-modified medium; a dedicated sample preparation by FIB has been defined to fix cells. In the present study, the cytotoxic effects of CNTs with 91% and 97% of purity were compared and changes in the growth behaviour of cells after 3 days in culture with modified medium have been recorded, considering also the distribution of CNTs within cells. While lower purified CNTs induced a slight cytotoxic effect, homogeneously suspended CNTs with high purity were less cytotoxic, and the rate of cell growth remained constant. CNTs aggregated in bundles, showed high adhesion on cell membrane. Interestingly, CNTs bundles were observed inside cells, underneath the cell membrane, and despite of that, cells were extended, in good vitality conditions and no cell-degeneration was observed.

  9. Using synthetic biology to make cells tomorrow's test tubes.

    Science.gov (United States)

    Garcia, Hernan G; Brewster, Robert C; Phillips, Rob

    2016-04-18

    The main tenet of physical biology is that biological phenomena can be subject to the same quantitative and predictive understanding that physics has afforded in the context of inanimate matter. However, the inherent complexity of many of these biological processes often leads to the derivation of complex theoretical descriptions containing a plethora of unknown parameters. Such complex descriptions pose a conceptual challenge to the establishment of a solid basis for predictive biology. In this article, we present various exciting examples of how synthetic biology can be used to simplify biological systems and distill these phenomena down to their essential features as a means to enable their theoretical description. Here, synthetic biology goes beyond previous efforts to engineer nature and becomes a tool to bend nature to understand it. We discuss various recent and classic experiments featuring applications of this synthetic approach to the elucidation of problems ranging from bacteriophage infection, to transcriptional regulation in bacteria and in developing embryos, to evolution. In all of these examples, synthetic biology provides the opportunity to turn cells into the equivalent of a test tube, where biological phenomena can be reconstituted and our theoretical understanding put to test with the same ease that these same phenomena can be studied in the in vitro setting.

  10. Anomalous transport in the crowded world of biological cells.

    Science.gov (United States)

    Höfling, Felix; Franosch, Thomas

    2013-04-01

    A ubiquitous observation in cell biology is that the diffusive motion of macromolecules and organelles is anomalous, and a description simply based on the conventional diffusion equation with diffusion constants measured in dilute solution fails. This is commonly attributed to macromolecular crowding in the interior of cells and in cellular membranes, summarizing their densely packed and heterogeneous structures. The most familiar phenomenon is a sublinear, power-law increase of the mean-square displacement (MSD) as a function of the lag time, but there are other manifestations like strongly reduced and time-dependent diffusion coefficients, persistent correlations in time, non-Gaussian distributions of spatial displacements, heterogeneous diffusion and a fraction of immobile particles. After a general introduction to the statistical description of slow, anomalous transport, we summarize some widely used theoretical models: Gaussian models like fractional Brownian motion and Langevin equations for visco-elastic media, the continuous-time random walk model, and the Lorentz model describing obstructed transport in a heterogeneous environment. Particular emphasis is put on the spatio-temporal properties of the transport in terms of two-point correlation functions, dynamic scaling behaviour, and how the models are distinguished by their propagators even if the MSDs are identical. Then, we review the theory underlying commonly applied experimental techniques in the presence of anomalous transport like single-particle tracking, fluorescence correlation spectroscopy (FCS) and fluorescence recovery after photobleaching (FRAP). We report on the large body of recent experimental evidence for anomalous transport in crowded biological media: in cyto- and nucleoplasm as well as in cellular membranes, complemented by in vitro experiments where a variety of model systems mimic physiological crowding conditions. Finally, computer simulations are discussed which play an important

  11. Mutagenic Effects of Iron Oxide Nanoparticles on Biological Cells.

    Science.gov (United States)

    Dissanayake, Niluka M; Current, Kelley M; Obare, Sherine O

    2015-09-30

    In recent years, there has been an increased interest in the design and use of iron oxide materials with nanoscale dimensions for magnetic, catalytic, biomedical, and electronic applications. The increased manufacture and use of iron oxide nanoparticles (IONPs) in consumer products as well as industrial processes is expected to lead to the unintentional release of IONPs into the environment. The impact of IONPs on the environment and on biological species is not well understood but remains a concern due to the increased chemical reactivity of nanoparticles relative to their bulk counterparts. This review article describes the impact of IONPs on cellular genetic components. The mutagenic impact of IONPs may damage an organism's ability to develop or reproduce. To date, there has been experimental evidence of IONPs having mutagenic interactions on human cell lines including lymphoblastoids, fibroblasts, microvascular endothelial cells, bone marrow cells, lung epithelial cells, alveolar type II like epithelial cells, bronchial fibroblasts, skin epithelial cells, hepatocytes, cerebral endothelial cells, fibrosarcoma cells, breast carcinoma cells, lung carcinoma cells, and cervix carcinoma cells. Other cell lines including the Chinese hamster ovary cells, mouse fibroblast cells, murine fibroblast cells, Mytilus galloprovincialis sperm cells, mice lung cells, murine alveolar macrophages, mice hepatic and renal tissue cells, and vero cells have also shown mutagenic effects upon exposure to IONPs. We further show the influence of IONPs on microorganisms in the presence and absence of dissolved organic carbon. The results shed light on the OPEN ACCESS Int. J. Mol. Sci. 2015, 16 23483 transformations IONPs undergo in the environment and the nature of the potential mutagenic impact on biological cells.

  12. Investigating Climate Change and Reproduction: Experimental Tools from Evolutionary Biology

    Directory of Open Access Journals (Sweden)

    Oliver Y. Martin

    2012-09-01

    Full Text Available It is now generally acknowledged that climate change has wide-ranging biological consequences, potentially leading to impacts on biodiversity. Environmental factors can have diverse and often strong effects on reproduction, with obvious ramifications for population fitness. Nevertheless, reproductive traits are often neglected in conservation considerations. Focusing on animals, recent progress in sexual selection and sexual conflict research suggests that reproductive costs may pose an underestimated hurdle during rapid climate change, potentially lowering adaptive potential and increasing extinction risk of certain populations. Nevertheless, regime shifts may have both negative and positive effects on reproduction, so it is important to acquire detailed experimental data. We hence present an overview of the literature reporting short-term reproductive consequences of exposure to different environmental factors. From the enormous diversity of findings, we conclude that climate change research could benefit greatly from more coordinated efforts incorporating evolutionary approaches in order to obtain cross-comparable data on how individual and population reproductive fitness respond in the long term. Therefore, we propose ideas and methods concerning future efforts dealing with reproductive consequences of climate change, in particular by highlighting the advantages of multi-generational experimental evolution experiments.

  13. Microbial-enzymatic-hybrid biological fuel cell with optimized growth conditions for Shewanella oneidensis DSP-10.

    Science.gov (United States)

    Roy, Jared N; Luckarift, Heather R; Sizemore, Susan R; Farrington, Karen E; Lau, Carolin; Johnson, Glenn R; Atanassov, Plamen

    2013-07-10

    In this work we present a biological fuel cell fabricated by combining a Shewanella oneidensis microbial anode and a laccase-modified air-breathing cathode. This concept is devised as an extension to traditional biochemical methods by incorporating diverse biological catalysts with the aim of powering small devices. In preparing the biological fuel cell anode, novel hierarchical-structured architectures and biofilm configurations were investigated. A method for creating an artificial biofilm based on encapsulating microorganisms in a porous, thin film of silica was compared with S. oneidensis biofilms that were allowed to colonize naturally. Results indicate comparable current and power densities for artificial and natural biofilm formations, based on growth characteristics. As a result, this work describes methods for creating controllable and reproducible bio-anodes and demonstrates the versatility of hybrid biological fuel cells.

  14. TinkerCell: modular CAD tool for synthetic biology

    Directory of Open Access Journals (Sweden)

    Bergmann Frank T

    2009-10-01

    Full Text Available Abstract Background Synthetic biology brings together concepts and techniques from engineering and biology. In this field, computer-aided design (CAD is necessary in order to bridge the gap between computational modeling and biological data. Using a CAD application, it would be possible to construct models using available biological "parts" and directly generate the DNA sequence that represents the model, thus increasing the efficiency of design and construction of synthetic networks. Results An application named TinkerCell has been developed in order to serve as a CAD tool for synthetic biology. TinkerCell is a visual modeling tool that supports a hierarchy of biological parts. Each part in this hierarchy consists of a set of attributes that define the part, such as sequence or rate constants. Models that are constructed using these parts can be analyzed using various third-party C and Python programs that are hosted by TinkerCell via an extensive C and Python application programming interface (API. TinkerCell supports the notion of a module, which are networks with interfaces. Such modules can be connected to each other, forming larger modular networks. TinkerCell is a free and open-source project under the Berkeley Software Distribution license. Downloads, documentation, and tutorials are available at http://www.tinkercell.com. Conclusion An ideal CAD application for engineering biological systems would provide features such as: building and simulating networks, analyzing robustness of networks, and searching databases for components that meet the design criteria. At the current state of synthetic biology, there are no established methods for measuring robustness or identifying components that fit a design. The same is true for databases of biological parts. TinkerCell's flexible modeling framework allows it to cope with changes in the field. Such changes may involve the way parts are characterized or the way synthetic networks are modeled

  15. Single-cell sequencing in stem cell biology.

    Science.gov (United States)

    Wen, Lu; Tang, Fuchou

    2016-04-15

    Cell-to-cell variation and heterogeneity are fundamental and intrinsic characteristics of stem cell populations, but these differences are masked when bulk cells are used for omic analysis. Single-cell sequencing technologies serve as powerful tools to dissect cellular heterogeneity comprehensively and to identify distinct phenotypic cell types, even within a 'homogeneous' stem cell population. These technologies, including single-cell genome, epigenome, and transcriptome sequencing technologies, have been developing rapidly in recent years. The application of these methods to different types of stem cells, including pluripotent stem cells and tissue-specific stem cells, has led to exciting new findings in the stem cell field. In this review, we discuss the recent progress as well as future perspectives in the methodologies and applications of single-cell omic sequencing technologies.

  16. Environmental scanning electron microscopy in cell biology.

    Science.gov (United States)

    McGregor, J E; Staniewicz, L T L; Guthrie Neé Kirk, S E; Donald, A M

    2013-01-01

    Environmental scanning electron microscopy (ESEM) (1) is an imaging technique which allows hydrated, insulating samples to be imaged under an electron beam. The resolution afforded by this technique is higher than conventional optical microscopy but lower than conventional scanning electron microscopy (CSEM). The major advantage of the technique is the minimal sample preparation needed, making ESEM quick to use and the images less susceptible to the artifacts that the extensive sample preparation usually required for CSEM may introduce. Careful manipulation of both the humidity in the microscope chamber and the beam energy are nevertheless essential to prevent dehydration and beam damage artifacts. In some circumstances it is possible to image live cells in the ESEM (2).In the following sections we introduce the fundamental principles of ESEM imaging before presenting imaging protocols for plant epidermis, mammalian cells, and bacteria. In the first two cases samples are imaged using the secondary electron (topographic) signal, whereas a transmission technique is employed to image bacteria.

  17. Investigation into the non-biological outputs of mechanical-biological treatment facilities.

    Science.gov (United States)

    Cook, Ed; Wagland, Stuart; Coulon, Frédéric

    2015-12-01

    Mechanical-biological and biological-mechanical treatment (MBT/BMT) are effective methods for reducing biogenic additions to landfill, producing fuel products and recovering recyclate from residual waste. However, large amounts of contamination in the non-biological outputs reduce their market value. The aim of this study was therefore to identify the principal drivers and barriers to the marketability of ferrous metals (MBTFe) and heavy inert rejects (MBTr) recovered from four UK MBT/BMT plants. The plants were either using biodrying or anaerobic digestion (AD-MBT) for biological processing. Samples were collected at the different recovery stage processes and characterised for elemental composition and particle size distribution. Results showed that processes at the two biodrying plants produced MBTFe with 10% less contamination by non-target materials than the two AD-MBT plants. Further to this, approximately 10% of the MBTFe fraction sampled at all four facilities comprised non-target material which had become entrapped in the folds of metal food containers. A possible cause is waste comminution in the cutting gap of the low-speed high-torque cutting mills. Upgrading MBTFe outputs could save the UK MBT/BMT industry up to £ 4.4 million per annum which equates to £ 230,000 per annum for an average sized facility (i.e. capacity 108,000 tpa). Glass content in the MBTr samples ranged between 44% and 62%, however all plants showed approximately 85% combined content of glass, bricks, stones and ceramics. The biodegradable content in the MBTr samples indicated that only minimal upgrade would be required to achieve the Landfill Directive requirements for inert waste. Again valorisation of MBTr could save the UK MBT/BMT industry up to £ 1.9 million pa which equates to £ 160,000 per annum for an average sized facility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The cell biology of fat expansion

    OpenAIRE

    Rutkowski, Joseph M.; Stern, Jennifer H.; Scherer, Philipp E.

    2015-01-01

    Adipose tissue is a complex, multicellular organ that profoundly influences the function of nearly all other organ systems through its diverse metabolite and adipokine secretome. Adipocytes are the primary cell type of adipose tissue and play a key role in maintaining energy homeostasis. The efficiency with which adipose tissue responds to whole-body energetic demands reflects the ability of adipocytes to adapt to an altered nutrient environment, and has profound systemic implications. Deciph...

  19. Systems-biology dissection of eukaryotic cell growth

    Directory of Open Access Journals (Sweden)

    Andrews Justen

    2010-05-01

    Full Text Available Abstract A recent article in BMC Biology illustrates the use of a systems-biology approach to integrate data across the transcriptome, proteome and metabolome of budding yeast in order to dissect the relationship between nutrient conditions and cell growth. See research article http://jbiol.com/content/6/2/4 and http://www.biomedcentral.com/1741-7007/8/68

  20. The cell biology of cryptosporidium infection.

    Science.gov (United States)

    O'Hara, Steven P; Chen, Xian-Ming

    2011-08-01

    Cryptosporidiosis remains a significant cause of enteric disease worldwide. Basic investigations of host: pathogen interactions have revealed the intricate processes mediating infection. The following summarizes the interactions that mediate infection and the host responses that both permit and ultimately clear the infection.

  1. Primary culture of glial cells from mouse sympathetic cervical ganglion: a valuable tool for studying glial cell biology.

    Science.gov (United States)

    de Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

    2010-12-15

    Central nervous system glial cells as astrocytes and microglia have been investigated in vitro and many intracellular pathways have been clarified upon various stimuli. Peripheral glial cells, however, are not as deeply investigated in vitro despite its importance role in inflammatory and neurodegenerative diseases. Based on our previous experience of culturing neuronal cells, our objective was to standardize and morphologically characterize a primary culture of mouse superior cervical ganglion glial cells in order to obtain a useful tool to study peripheral glial cell biology. Superior cervical ganglia from neonatal C57BL6 mice were enzymatically and mechanically dissociated and cells were plated on diluted Matrigel coated wells in a final concentration of 10,000cells/well. Five to 8 days post plating, glial cell cultures were fixed for morphological and immunocytochemical characterization. Glial cells showed a flat and irregular shape, two or three long cytoplasm processes, and round, oval or long shaped nuclei, with regular outline. Cell proliferation and mitosis were detected both qualitative and quantitatively. Glial cells were able to maintain their phenotype in our culture model including immunoreactivity against glial cell marker GFAP. This is the first description of immunocytochemical characterization of mouse sympathetic cervical ganglion glial cells in primary culture. This work discusses the uses and limitations of our model as a tool to study many aspects of peripheral glial cell biology. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Models to Study NK Cell Biology and Possible Clinical Application.

    Science.gov (United States)

    Zamora, Anthony E; Grossenbacher, Steven K; Aguilar, Ethan G; Murphy, William J

    2015-08-03

    Natural killer (NK) cells are large granular lymphocytes of the innate immune system, responsible for direct targeting and killing of both virally infected and transformed cells. NK cells rapidly recognize and respond to abnormal cells in the absence of prior sensitization due to their wide array of germline-encoded inhibitory and activating receptors, which differs from the receptor diversity found in B and T lymphocytes that is due to the use of recombination-activation gene (RAG) enzymes. Although NK cells have traditionally been described as natural killers that provide a first line of defense prior to the induction of adaptive immunity, a more complex view of NK cells is beginning to emerge, indicating they may also function in various immunoregulatory roles and have the capacity to shape adaptive immune responses. With the growing appreciation for the diverse functions of NK cells, and recent technological advancements that allow for a more in-depth understanding of NK cell biology, we can now begin to explore new ways to manipulate NK cells to increase their clinical utility. In this overview unit, we introduce the reader to various aspects of NK cell biology by reviewing topics ranging from NK cell diversity and function, mouse models, and the roles of NK cells in health and disease, to potential clinical applications. © 2015 by John Wiley & Sons, Inc. Copyright © 2015 John Wiley & Sons, Inc.

  3. Investigation into biologically active constituents of Geum rivale L.

    Science.gov (United States)

    Owczarek, Aleksandra; Gudej, Jan

    2013-01-01

    Aerial and underground parts of Geum rivale (Rosaceae) were investigated. Tiliroside, gallic acid, ellagic acid and a sterol fraction were isolated from aerial parts of the plant. The sterol fraction was analyzed using GC-MS. Eleven phenolic acids were identified in aerial parts of the plant, and eight in underground parts, by means of RP-HPLC analysis. The quantitative determination of phenolic acids, tannins and flavonoids was also carried out.

  4. Stem cell biology and cell transplantation therapy in the retina.

    Science.gov (United States)

    Osakada, Fumitaka; Hirami, Yasuhiko; Takahashi, Masayo

    2010-01-01

    Embryonic stem (ES) cells, which are derived from the inner cell mass of mammalian blastocyst stage embryos, have the ability to differentiate into any cell type in the body and to grow indefinitely while maintaining pluripotency. During development, cells undergo progressive and irreversible differentiation into specialized adult cell types. Remarkably, in spite of this restriction in potential, adult somatic cells can be reprogrammed and returned to the naive state of pluripotency found in the early embryo simply by forcing expression of a defined set of transcription factors. These induced pluripotent stem (iPS) cells are molecularly and functionally equivalent to ES cells and provide powerful in vitro models for development, disease, and drug screening, as well as material for cell replacement therapy. Since functional impairment results from cell loss in most central nervous system (CNS) diseases, recovery of lost cells is an important treatment strategy. Although adult neurogenesis occurs in restricted regions, the CNS has poor potential for regeneration to compensate for cell loss. Thus, cell transplantation into damaged or diseased CNS tissues is a promising approach to treating various neurodegenerative disorders. Transplantation of photoreceptors or retinal pigment epithelium cells derived from human ES cells can restore some visual function. Patient-specific iPS cells may lead to customized cell therapy. However, regeneration of retinal function will require a detailed understanding of eye development, visual system circuitry, and retinal degeneration pathology. Here, we review the current progress in retinal regeneration, focusing on the therapeutic potential of pluripotent stem cells.

  5. Finding the key - cell biology and science education.

    Science.gov (United States)

    Miller, Kenneth R

    2010-12-01

    No international research community, cell biology included, can exist without an educational community to renew and replenish it. Unfortunately, cell biology researchers frequently regard their work as independent of the process of education and see little reason to reach out to science teachers. For cell biology to continue to prosper, I argue that researchers must support education in at least three ways. First, we must view education and research as part of a single scientific community. Second, we should take advantage of new technologies to connect the research laboratory to the classroom. Finally, we must take the initiative in defending the integrity of science teaching, particularly when education is under attack for political or religious reasons.

  6. Applications of Structural Biology and Bioinformatics in the Investigation of Oxidative Stress-Related Processes

    NARCIS (Netherlands)

    Bersch, Beate; Groves, Matthew; Johann, Klare; Torda, Andrew; Ortiz, Dario; Laher, I.

    2014-01-01

    Reactive oxygen species (ROS)-mediated dysfunction of certain biological processes is implicated in different diseases in humans, including cardiovascular, cancer, or neurodegenerative disorders. Not only human cells and tissues are affected by ROS but also all other biological systems, including pl

  7. Concise Review: Asymmetric Cell Divisions in Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Florian Murke

    2015-11-01

    Full Text Available Somatic stem cells are rare cells with unique properties residing in many organs and tissues. They are undifferentiated cells responsible for tissue regeneration and homeostasis, and contain both the capacity to self-renew in order to maintain their stem cell potential and to differentiate towards tissue-specific, specialized cells. However, the knowledge about the mechanisms controlling somatic stem cell fate decisions remains sparse. One mechanism which has been described to control daughter cell fates in selected somatic stem cell systems is the process of asymmetric cell division (ACD. ACD is a tightly regulated and evolutionary conserved process allowing a single stem or progenitor cell to produce two differently specified daughter cells. In this concise review, we will summarize and discuss current concepts about the process of ACD as well as different ACD modes. Finally, we will recapitulate the current knowledge and our recent findings about ACD in human hematopoiesis.

  8. Investigation of the Biological Properties of (HeteroAromatic Thiosemicarbazones

    Directory of Open Access Journals (Sweden)

    Jaroslaw Polanski

    2012-11-01

    Full Text Available Two series of thiosemicarbazone-based iron chelators (twenty-seven compounds were designed and synthesized using a microwave-assisted approach. Quinoline and halogenated phenyl were selected as parent scaffolds on the basis of a similarity search. The lipophilicity of the synthesized compounds was measured using HPLC and then calculated. Primary in vitro screening of the synthesized compounds was performed against eight pathogenic fungal strains. Only a few compounds showed moderate activity against fungi, and (E-2-(quinolin-2-ylvinyl-N,N-dimethylhydrazine-carbothioamide appeared to be more effective than fluconazole against most of the fungal strains tested. Antiproliferative activity was measured using a human colon cancer cell line (HCT-116. Several of the tested compounds showed submicromolar antiproliferative activity. Compounds were also tested for their activity related to the inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts. The structure-activity relationships are discussed for all of the compounds.

  9. Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory.

    Science.gov (United States)

    Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V McNeil; Segarra, Verónica A

    2017-01-01

    Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented-one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research.

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

    Science.gov (United States)

    Moran, Marina

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

  11. A data integration approach for cell cycle analysis oriented to model simulation in systems biology

    Directory of Open Access Journals (Sweden)

    Mosca Ettore

    2007-08-01

    Full Text Available Abstract Background The cell cycle is one of the biological processes most frequently investigated in systems biology studies and it involves the knowledge of a large number of genes and networks of protein interactions. A deep knowledge of the molecular aspect of this biological process can contribute to making cancer research more accurate and innovative. In this context the mathematical modelling of the cell cycle has a relevant role to quantify the behaviour of each component of the systems. The mathematical modelling of a biological process such as the cell cycle allows a systemic description that helps to highlight some features such as emergent properties which could be hidden when the analysis is performed only from a reductionism point of view. Moreover, in modelling complex systems, a complete annotation of all the components is equally important to understand the interaction mechanism inside the network: for this reason data integration of the model components has high relevance in systems biology studies. Description In this work, we present a resource, the Cell Cycle Database, intended to support systems biology analysis on the Cell Cycle process, based on two organisms, yeast and mammalian. The database integrates information about genes and proteins involved in the cell cycle process, stores complete models of the interaction networks and allows the mathematical simulation over time of the quantitative behaviour of each component. To accomplish this task, we developed, a web interface for browsing information related to cell cycle genes, proteins and mathematical models. In this framework, we have implemented a pipeline which allows users to deal with the mathematical part of the models, in order to solve, using different variables, the ordinary differential equation systems that describe the biological process. Conclusion This integrated system is freely available in order to support systems biology research on the cell cycle and

  12. Molecular biology of testicular germ cell tumors.

    Science.gov (United States)

    Gonzalez-Exposito, R; Merino, M; Aguayo, C

    2016-06-01

    Testicular germ cell tumors (TGCTs) are the most common solid tumors in young adult men. They constitute a unique pathology because of their embryonic and germ origin and their special behavior. Genetic predisposition, environmental factors involved in their development and genetic aberrations have been under study in many works throughout the last years trying to explain the susceptibility and the transformation mechanism of TGCTs. Despite the high rate of cure in this type of tumors because its particular sensitivity to cisplatin, there are tumors resistant to chemotherapy for which it is needed to find new therapies. In the present work, it has been carried out a literature review on the most important molecular aspects involved in the onset and development of such tumors, as well as a review of the major developments regarding prognostic factors, new prognostic biomarkers and the possibility of new targeted therapies.

  13. A decade of molecular cell biology: achievements and challenges.

    Science.gov (United States)

    Akhtar, Asifa; Fuchs, Elaine; Mitchison, Tim; Shaw, Reuben J; St Johnston, Daniel; Strasser, Andreas; Taylor, Susan; Walczak, Claire; Zerial, Marino

    2011-09-23

    Nature Reviews Molecular Cell Biology celebrated its 10-year anniversary during this past year with a series of specially commissioned articles. To complement this, here we have asked researchers from across the field for their insights into how molecular cell biology research has evolved during this past decade, the key concepts that have emerged and the most promising interfaces that have developed. Their comments highlight the broad impact that particular advances have had, some of the basic understanding that we still require, and the collaborative approaches that will be essential for driving the field forward.

  14. Stem Cells: A Renaissance in Human Biology Research.

    Science.gov (United States)

    Wu, Jun; Izpisua Belmonte, Juan Carlos

    2016-06-16

    The understanding of human biology and how it relates to that of other species represents an ancient quest. Limited access to human material, particularly during early development, has restricted researchers to only scratching the surface of this inherently challenging subject. Recent technological innovations, such as single cell "omics" and human stem cell derivation, have now greatly accelerated our ability to gain insights into uniquely human biology. The opportunities afforded to delve molecularly into scarce material and to model human embryogenesis and pathophysiological processes are leading to new insights of human development and are changing our understanding of disease and choice of therapy options.

  15. Stem cell-based biological tooth repair and regeneration.

    Science.gov (United States)

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T

    2010-12-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regeneration of periodontal ligament lost in periodontal disease, and for generation of complete or partial tooth structures to form biological implants. As dental stem cells share properties with mesenchymal stem cells, there is also considerable interest in their wider potential to treat disorders involving mesenchymal (or indeed non-mesenchymal) cell derivatives, such as in Parkinson's disease.

  16. Apoptotic cell clearance: basic biology and therapeutic potential.

    Science.gov (United States)

    Poon, Ivan K H; Lucas, Christopher D; Rossi, Adriano G; Ravichandran, Kodi S

    2014-03-01

    The prompt removal of apoptotic cells by phagocytes is important for maintaining tissue homeostasis. The molecular and cellular events that underpin apoptotic cell recognition and uptake, and the subsequent biological responses, are increasingly better defined. The detection and disposal of apoptotic cells generally promote an anti-inflammatory response at the tissue level, as well as immunological tolerance. Consequently, defects in apoptotic cell clearance have been linked with various inflammatory diseases and autoimmunity. Conversely, under certain conditions, such as the killing of tumour cells by specific cell-death inducers, the recognition of apoptotic tumour cells can promote an immunogenic response and antitumour immunity. Here, we review the current understanding of the complex process of apoptotic cell clearance in physiology and pathology, and discuss how this knowledge could be harnessed for new therapeutic strategies.

  17. Synthetic Biology and Microbial Fuel Cells: Towards Self-Sustaining Life Support Systems

    Science.gov (United States)

    Hogan, John Andrew

    2014-01-01

    NASA ARC and the J. Craig Venter Institute (JCVI) collaborated to investigate the development of advanced microbial fuels cells (MFCs) for biological wastewater treatment and electricity production (electrogenesis). Synthetic biology techniques and integrated hardware advances were investigated to increase system efficiency and robustness, with the intent of increasing power self-sufficiency and potential product formation from carbon dioxide. MFCs possess numerous advantages for space missions, including rapid processing, reduced biomass and effective removal of organics, nitrogen and phosphorus. Project efforts include developing space-based MFC concepts, integration analyses, increasing energy efficiency, and investigating novel bioelectrochemical system applications

  18. WHOLE CELL TOMOGRAPHY/MOLECULAR BIOLOGY/STRUCTURAL BIOLOGY: Affordable x-ray microscopy with nanoscale resolution

    Energy Technology Data Exchange (ETDEWEB)

    Evans, James E.; Blackborow, Paul; Horne, Stephen J.; Gelb, Jeff

    2013-03-01

    Biological research spans 10 orders of magnitude from angstroms to meters. While electron microscopy can reveal structural details at most of these spatial length scales, transmission electron tomography only reliably reconstructs three-dimensional (3-D) volumes of cellular material with a spatial resolution between 1-5 nm from samples less than 500 nm thick1. Most biological cells are 2-30 times thicker than this threshold, which means that a cell must be cut into consecutive slices with each slice reconstructed individually in order to approximate the contextual information of the entire cell. Fortunately, due to a larger penetration depth2, X-ray computed tomography bypasses the need to physically section a cell and enables imaging of intact cells and tissues on the micrometer or larger scale with tens to hundreds of nanometer spatial resolution. While the technique of soft x-ray microscopy has been extensively developed in synchrotron facilities, advancements in laboratory x-ray source designs now increase its accessibility by supporting commercial systems suitable for a standard laboratory. In this paper, we highlight a new commercial compact cryogenic soft x-ray microscope designed for a standard laboratory setting and explore its capabilities for mesoscopic investigations of intact prokaryotic and eukaryotic cells.

  19. The cell biology of CNS myelination.

    Science.gov (United States)

    Hughes, Ethan G; Appel, Bruce

    2016-08-01

    Myelination of axons in the central nervous system results from the remarkable ability of oligodendrocytes to wrap multiple axons with highly specialized membrane. Because myelin membrane grows as it ensheaths axons, cytoskeletal rearrangements that enable ensheathment must be coordinated with myelin production. Because the myelin sheaths of a single oligodendrocyte can differ in thickness and length, mechanisms that coordinate axon ensheathment with myelin growth likely operate within individual oligodendrocyte processes. Recent studies have revealed new information about how assembly and disassembly of actin filaments helps drive the leading edge of nascent myelin membrane around and along axons. Concurrently, other investigations have begun to uncover evidence of communication between axons and oligodendrocytes that can regulate myelin formation.

  20. Natural killer cell biology: an update and future directions.

    Science.gov (United States)

    Campbell, Kerry S; Hasegawa, Jun

    2013-09-01

    Natural killer (NK) cells constitute a minor subset of normal lymphocytes that initiate innate immune responses toward tumor and virus-infected cells. They can mediate spontaneous cytotoxicity toward these abnormal cells and rapidly secrete numerous cytokines and chemokines to promote subsequent adaptive immune responses. Significant progress has been made in the past 2 decades to improve our understanding of NK cell biology. Here we review recent discoveries, including a better comprehension of the "education" of NK cells to achieve functional competence during their maturation and the discovery of "memory" responses by NK cells, suggesting that they might also contribute to adaptive immunity. The improved understanding of NK cell biology has forged greater awareness that these cells play integral early roles in immune responses. In addition, several promising clinical therapies have been used to exploit NK cell functions in treating patients with cancer. As our molecular understanding improves, these and future immunotherapies should continue to provide promising strategies to exploit the unique functions of NK cells to treat cancer, infections, and other pathologic conditions.

  1. 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.

  2. Orbital rotation of biological cells using two fibre probes

    Science.gov (United States)

    Huang, J.; Liu, X.; Zhang, Y.; Li, B.

    2017-03-01

    We report the orbital rotation of biological cells using two tapered fibre probes. We launched laser beams into the probes at a wavelength of 980 nm and rotated 5 µm-diameter yeast cells and 13.5 µm-diameter human leukemic K562 by optical force. The rotation period varied from 1.59 to 2.41 s for the yeast cells and was 4.83 s for the human leukemic K562. The rotation direction of the cells can be controlled by adjusting the position of the two probes. The experimental results were interpreted by theoretical analysis and numerical simulations.

  3. T Regulatory Cell Biology in Health and Disease.

    Science.gov (United States)

    Alroqi, Fayhan J; Chatila, Talal A

    2016-04-01

    Regulatory T (Treg) cells that express the transcription factor forkhead box protein P3 (FOXP3) play an essential role in enforcing immune tolerance to self tissues, regulating host-commensal flora interaction, and facilitating tissue repair. Their deficiency and/or dysfunction trigger unbridled autoimmunity and inflammation. A growing number of monogenic defects have been recognized that adversely impact Treg cell development, differentiation, and/or function, leading to heritable diseases of immune dysregulation and autoimmunity. In this article, we review recent insights into Treg cell biology and function, with particular attention to lessons learned from newly recognized clinical disorders of Treg cell deficiency.

  4. Biological Activity of Polynesian Calophyllum inophyllum Oil Extract on Human Skin Cells.

    Science.gov (United States)

    Ansel, Jean-Luc; Lupo, Elise; Mijouin, Lily; Guillot, Samuel; Butaud, Jean-François; Ho, Raimana; Lecellier, Gaël; Raharivelomanana, Phila; Pichon, Chantal

    2016-07-01

    Oil from the nuts of Calophyllum inophyllum, locally called "Tamanu oil" in French Polynesia, was traditionally used for wound healing and to cure various skin problems and ailments. The skin-active effect of "Tamanu oil emulsion" was investigated on human skin cells (keratinocytes and dermal fibroblasts) and showed cell proliferation, glycosaminoglycan and collagen production, and wound healing activity. Transcriptomic analysis of the treated cells revealed gene expression modulation including genes involved in the metabolic process implied in O-glycan biosynthesis, cell adhesion, and cell proliferation. The presence of neoflavonoids as bioactive constituents in Tamanu oil emulsion may contribute to these biological activities. Altogether, consistent data related to targeted histological and cellular functions brought new highlights on the mechanisms involved in these biological processes induced by Tamanu oil effects in skin cells.

  5. Cell-free synthetic biology for in vitro prototype engineering.

    Science.gov (United States)

    Moore, Simon J; MacDonald, James T; Freemont, Paul S

    2017-06-15

    Cell-free transcription-translation is an expanding field in synthetic biology as a rapid prototyping platform for blueprinting the design of synthetic biological devices. Exemplar efforts include translation of prototype designs into medical test kits for on-site identification of viruses (Zika and Ebola), while gene circuit cascades can be tested, debugged and re-designed within rapid turnover times. Coupled with mathematical modelling, this discipline lends itself towards the precision engineering of new synthetic life. The next stages of cell-free look set to unlock new microbial hosts that remain slow to engineer and unsuited to rapid iterative design cycles. It is hoped that the development of such systems will provide new tools to aid the transition from cell-free prototype designs to functioning synthetic genetic circuits and engineered natural product pathways in living cells. © 2017 The Author(s).

  6. Innate immune pattern recognition: a cell biological perspective.

    Science.gov (United States)

    Brubaker, Sky W; Bonham, Kevin S; Zanoni, Ivan; Kagan, Jonathan C

    2015-01-01

    Receptors of the innate immune system detect conserved determinants of microbial and viral origin. Activation of these receptors initiates signaling events that culminate in an effective immune response. Recently, the view that innate immune signaling events rely on and operate within a complex cellular infrastructure has become an important framework for understanding the regulation of innate immunity. Compartmentalization within this infrastructure provides the cell with the ability to assign spatial information to microbial detection and regulate immune responses. Several cell biological processes play a role in the regulation of innate signaling responses; at the same time, innate signaling can engage cellular processes as a form of defense or to promote immunological memory. In this review, we highlight these aspects of cell biology in pattern-recognition receptor signaling by focusing on signals that originate from the cell surface, from endosomal compartments, and from within the cytosol.

  7. Cell biological regulation of division fate in vertebrate neuroepithelial cells.

    Science.gov (United States)

    Willardsen, Minde I; Link, Brian A

    2011-08-01

    The developing nervous system derives from neuroepithelial progenitor cells that divide to generate all of the mature neuronal types. For the proper complement of cell types to form, the progenitors must produce postmitotic cells, yet also replenish the progenitor pool. Progenitor divisions can be classified into three general types: symmetric proliferative (producing two progenitors), asymmetric neurogenic (producing one progenitor and one postmitotic cell), and symmetric neurogenic (producing two postmitotic cells). The appropriate ratios for these modes of cell division require intrinsic polarity, which is one of the characteristics that define neuroepithelial progenitor cells. The type of division an individual progenitor undergoes can be influenced by cellular features, or behaviors, which are heterogeneous within the population of progenitors. Here we review three key cellular parameters, asymmetric inheritance, cell cycle kinetics, and interkinetic nuclear migration, and the possible mechanisms for how these features influence progenitor fates. Copyright © 2011 Wiley-Liss, Inc.

  8. Information Literacy in Biology Education: An Example from an Advanced Cell Biology Course

    Science.gov (United States)

    2005-01-01

    Information literacy skills are critically important for the undergraduate biology student. The ability to find, understand, evaluate, and use information, whether from the scientific literature or from Web resources, is essential for a good understanding of a topic and for the conduct of research. A project in which students receive information literacy instruction and then proceed to select, update, and write about a current research topic in an upper-level cell biology course is described. Students research the chosen topic using paper and electronic resources, generate a list of relevant articles, prepare abstracts based on papers read, and, finally, prepare a “state-of-the-art” paper on the topic. This approach, which extends over most of one semester, has resulted in a number of well-researched and well-written papers that incorporate some of the latest research in cell biology. The steps in this project have also led to students who are prepared to address future projects on new and complex topics. The project is part of an undergraduate course in cell biology, but parts of the assignments can be modified to fit a variety of subject areas and levels. PMID:16341261

  9. A unified cell biological perspective on axon-myelin injury

    OpenAIRE

    Simons, Mikael; Misgeld, Thomas; Kerschensteiner, Martin

    2014-01-01

    Demyelination and axon loss are pathological hallmarks of the neuroinflammatory disorder multiple sclerosis (MS). Although we have an increasingly detailed understanding of how immune cells can damage axons and myelin individually, we lack a unified view of how the axon–myelin unit as a whole is affected by immune-mediated attack. In this review, we propose that as a result of the tight cell biological interconnection of axons and myelin, damage to either can spread, which might convert a loc...

  10. Investigating Lebanese Grade Seven Biology Teachers Mathematical Knowledge and Skills: A Case Study

    Science.gov (United States)

    Raad, Nawal Abou; Chatila, Hanadi

    2016-01-01

    This paper investigates Lebanese grade 7 biology teachers' mathematical knowledge and skills, by exploring how they explain a visual representation in an activity depending on the mathematical concept "Function". Twenty Lebanese in-service biology teachers participated in the study, and were interviewed about their explanation for the…

  11. [New insights into adipose cell biology].

    Science.gov (United States)

    Burcelin, Rémy

    2013-01-01

    Our research focuses on the molecular mechanisms controlling glycemia in healthy and diabetic individuals. Diabetes is now considered as a worldwide epidemic by WHO, and is predicted to affect several hundred million people in the near future. Current therapies have failed to prevent or control hyperglycemia, as well as the deleterious cardiovascular consequences of the disease have increased. New paradigms are thus needed to develop novel therapeutic strategies. Over the last 15 years, we have been studying the intestine as a major regulator of the integrated cross-talk between the brain, liver, pancreas, muscles and blood vessels required for glycemic control. As a first example, we identified that during a meal the glucose transporter GLUT2 and the intestinal hormone glucagon-like peptide-1 (GLP-1) are involved in glucose detection by the entero-portal system. This was done using highly innovative experimental techniques in the awake free moving mouse. We then found that the enteric-vagal nervous system transmits this nutritional information towards the brain stem and hypothalamus, where leptin, neuropeptide Y and GLP-1 relay the enteric signal to control the endocrine pancreas (insulin-glucagon secretion), the liver (glycogen metabolism), the vascular system (vasodilation, arterial flow), and muscle metabolism. This "anticipatory metabolic reflex " is altered during diabetes and might thus represent a new pharmacological target. Subsequently, while investigating the molecular mechanisms responsible for regulating this new physiological pathway, we discovered that a fat-rich diabetogenic diet alters the intestinal microbiota and permeability. This leads to an increase in the concentration of plasma lipopolysaccharides (LPS), which causes metabolic endotoxemia responsible for the induction of low-grade inflammation that characterizes type 2 diabetes, insulin resistance, adipose tissue development and hepatic lipid storage. We then showed that bacteria can be

  12. Investigation of endosome and lysosome biology by ultra pH-sensitive nanoprobes.

    Science.gov (United States)

    Wang, Chensu; Zhao, Tian; Li, Yang; Huang, Gang; White, Michael A; Gao, Jinming

    2016-09-06

    Endosomes and lysosomes play a critical role in various aspects of cell physiology such as nutrient sensing, receptor recycling, protein/lipid catabolism, and cell death. In drug delivery, endosomal release of therapeutic payloads from nanocarriers is also important in achieving efficient delivery of drugs to reach their intracellular targets. Recently, we invented a library of ultra pH-sensitive (UPS) nanoprobes with exquisite fluorescence response to subtle pH changes. The UPS nanoprobes also displayed strong pH-specific buffer effect over small molecular bases with broad pH responses (e.g., chloroquine and NH4Cl). Tunable pH transitions from 7.4 to 4.0 of UPS nanoprobes cover the entire physiological pH of endocytic organelles (e.g., early and late endosomes) and lysosomes. These unique physico-chemical properties of UPS nanoprobes allowed a 'detection and perturbation' strategy for the investigation of luminal pH in cell signaling and metabolism, which introduces a nanotechnology-enabled paradigm for the biological studies of endosomes and lysosomes.

  13. Teaching cell and molecular biology for gender equity.

    Science.gov (United States)

    Sible, Jill C; Wilhelm, Dayna E; Lederman, Muriel

    2006-01-01

    Science, technology, engineering, and math (STEM) fields, including cell biology, are characterized by the "leaky pipeline" syndrome in which, over time, women leave the discipline. The pipeline itself and the pond into which it empties may not be neutral. Explicating invisible norms, attitudes, and practices by integrating social studies of science into science education may be the necessary first step in helping female students persist in STEM disciplines. In 2003 and 2004, a sophomore Cell and Molecular Biology course at Virginia Tech (Blacksburg, VA) was taught integrating social studies of science with standard material. The course was successfully implemented, teaching students factual content while increasing awareness of the cultures of science and their self-confidence in engaging with the subject. Course evaluation data indicated that females in particular perceived greater gains in logical thinking and problem-solving abilities than females in a traditional cell biology course. Consistent with K-12 studies, males in this class were likely to view scientists as male only, whereas females viewed scientists as male and female. This pilot project demonstrates that social studies can be integrated successfully in a cell biology course. Longitudinal studies of this cohort of students will indicate whether this approach contributes to the retention of women in the field.

  14. Human mesenchymal stromal cells : biological characterization and clinical application

    NARCIS (Netherlands)

    Bernardo, Maria Ester

    2010-01-01

    This thesis focuses on the characterization of the biological and functional properties of human mesenchymal stromal cells (MSCs), isolated from different tissue sources. The differentiation capacity of MSCs from fetal and adult tissues has been tested and compared. Umbilical cord blood (UCB) has be

  15. Teaching Cell and Molecular Biology for Gender Equity

    Science.gov (United States)

    Sible, Jill C.; Wilhelm, Dayna E.; Lederman, Muriel

    2006-01-01

    Science, technology, engineering, and math (STEM) fields, including cell biology, are characterized by the "leaky pipeline" syndrome in which, over time, women leave the discipline. The pipeline itself and the pond into which it empties may not be neutral. Explicating invisible norms, attitudes, and practices by integrating social…

  16. A short guide to technology development in cell biology

    NARCIS (Netherlands)

    B. van Steensel (Bas)

    2015-01-01

    textabstractNew technologies drive progress in many research fields, including cell biology. Much of technological innovation comes from "bottom-up" efforts by individual students and postdocs. However, technology development can be challenging, and a successful outcome depends on many factors. This

  17. The time is right: proteome biology of stem cells.

    NARCIS (Netherlands)

    Whetton, A.D.; Williamson, A.J.K.; Krijgsveld, J.; Lee, B.H.; Lemischka, I.; Oh, S.; Pera, M.; Mummery, C.L.; Heck, A.J.R.

    2008-01-01

    In stem cell biology, there is a growing need for advanced technologies that may help to unravel the molecular mechanisms of self-renewal and differentiation. Proteomics, the comprehensive analysis of proteins, is such an emerging technique. To facilitate interactions between specialists in

  18. Visualisation of the information resources for cell biology

    OpenAIRE

    Malchanau, Andrei; Nijholt, Anton; Roosendaal, Hans E.

    2005-01-01

    Intelligent multimodal interfaces can facilitate scientists in utilising available information resources. Combining scientific visualisations with interactive and intelligent tools can help create a “habitable” information space. Development of such tools remains largely iterative. We discuss an ongoing implementation of intelligent interactive visualisation of information resources in cell biology.

  19. Teaching Cell and Molecular Biology for Gender Equity

    Science.gov (United States)

    Sible, Jill C.; Wilhelm, Dayna E.; Lederman, Muriel

    2006-01-01

    Science, technology, engineering, and math (STEM) fields, including cell biology, are characterized by the "leaky pipeline" syndrome in which, over time, women leave the discipline. The pipeline itself and the pond into which it empties may not be neutral. Explicating invisible norms, attitudes, and practices by integrating social…

  20. Textbook Errors and Misconceptions in Biology: Cell Energetics.

    Science.gov (United States)

    Storey, Richard D.

    1992-01-01

    Discusses misconceptions and outdated models appearing in biology textbooks for concepts involving bioenergetics and chemical reactions; adenosine triphosphate (ATP) as the energy currency of cells; the myth of high energy phosphate bonds; structural properties of ATP; ATP production from respiration and fermentation; ATP as an energy storage…

  1. A short guide to technology development in cell biology

    NARCIS (Netherlands)

    B. van Steensel (Bas)

    2015-01-01

    textabstractNew technologies drive progress in many research fields, including cell biology. Much of technological innovation comes from "bottom-up" efforts by individual students and postdocs. However, technology development can be challenging, and a successful outcome depends on many factors. This

  2. Biology 23. Unit One -- The Cell: Structure and Physiology.

    Science.gov (United States)

    Nederland Independent School District, TX.

    GRADES OR AGES: Not given. SUBJECT MATTER: Biology, the structure and physiology of the cell. ORGANIZATION AND PHYSICAL APPEARANCE: There are four sections: a) objectives for the unit, b) bibliography, c) activities, and d) evaluation. The guide is directed to the student rather than the teacher. The guide is mimeographed and stapled, with no…

  3. The time is right: proteome biology of stem cells.

    NARCIS (Netherlands)

    Whetton, A.D.; Williamson, A.J.K.; Krijgsveld, J.; Lee, B.H.; Lemischka, I.; Oh, S.; Pera, M.; Mummery, C.L.; Heck, A.J.R.

    2008-01-01

    In stem cell biology, there is a growing need for advanced technologies that may help to unravel the molecular mechanisms of self-renewal and differentiation. Proteomics, the comprehensive analysis of proteins, is such an emerging technique. To facilitate interactions between specialists in proteomi

  4. The Palade symposium: celebrating cell biology at its best.

    Science.gov (United States)

    Schmid, Sandra L; Farquhar, Marilyn G

    2010-07-15

    A symposium was held at the University of California, San Diego, to honor the contributions of Nobel Laureate, George Palade, to cell biology. The speakers included Günter Blobel, on the structure and function of nuclear pore complexes; Peter Walter, on the unfolded protein response in health and disease; Randy Schekman, on human disease-linked mutations in the COPII machinery; Scott Emr, on the regulation of plasma membrane composition by selective endocytosis; Roger Kornberg, on the structure and function of the transcription machinery; Peter Novick, on the regulation of rab GTPases along the secretory pathway; Jim Spudich, on the mechanism of the enigmatic myosin VI motor; and Joe Goldstein, on the function of the Niemann-Pick C (NPC)-linked gene products, NPC1 and NPC2, in cholesterol transport. Their work showcased the multidisciplinary nature, diversity, and vitality of cell biology. In the words of George Palade, their talks also illustrated "how cell biology could be used to understand disease and how disease could be used to discover normal cell biology." An integrated understanding of the cellular machinery will be essential in tackling the plethora of questions and challenges posed by completion of the human genome and for understanding the molecular mechanisms underlying human disease.

  5. Mesenchymal stem cells: cell biology and potential use in therapy

    DEFF Research Database (Denmark)

    Kassem, Moustapha; Kristiansen, Malthe; Abdallah, Basem M

    2004-01-01

    are currently available for isolation of the mesenchymal stem cells based on their physical and immunological characteristics. Because of the ease of their isolation and their extensive differentiation potential, mesenchymal stem cells are among the first stem cell types to be introduced in the clinic. Recent...... studies have demonstrated that the life span of mesenchymal stem cells in vitro can be extended by increasing the levels of telomerase expression in the cells and thus allowing culture of large number of cells needed for therapy. In addition, it has been shown that it is possible to culture the cells...... for generalized diseases, local implantation for local tissue defects, as a vehicle for genes in gene therapy protocols or to generate transplantable tissues and organs in tissue engineering protocols. The results of these initial trials are very encouraging and several clinical trials are under way to study...

  6. Measurements and interpretations of light scattering from intact biological cells

    Science.gov (United States)

    Wilson, Jeremy D.

    Visible light interacts with biological cells primarily through elastic scattering. The details of how cells scatter light depend on their morphology and their substructures. In this thesis we first present a series of experiments and models to discern the specific contributions of certain sub-cellular constituents to whole-cell scattering. Exploiting the findings of those studies, we report on experiments within model systems of cell death that demonstrate the potential of light scattering measurements as a tool in modern biology. Instrumentation capable of exploiting the findings of this thesis from a biology-relevant microscopy platform is designed and developed. A Mie theory based interpretation of light scattering signals originating from a collection of particles with a broad size distribution is developed. Upon applying this model to scattering data from intact cells, we find that it robustly extracts the size scale of dominant light scattering particles, suggests that scattering measurements are sensitive primarily to mitochondrial and lysosomal morphology, and unites conflicting results in the literature. Using this model as a basis, we present a collection of studies in which we use various strategies of photodynamic therapy (PDT) as a biophysical tool to perturb mitochondria and lysosomes, and observe the effects of these perturbations on whole-cell scattering. Through these experiments, we are able to discern the individual contributions of mitochondria and lysosomes to whole-cell light scattering, and demonstrate that mitochondria are responsible for roughly 80% of the scattering signal. Results of experiments aimed at demonstrating the potential role that light scattering measurements have to play in future studies of cell death biology are presented. We first show that mitochondrial-PDT-induced morphology changes measured with light scattering map into the cell killing efficacy of the therapy. We next demonstrate that mitochondrial

  7. Stem cell biology and regenerative medicine for neonatal lung diseases.

    Science.gov (United States)

    Kang, Martin; Thébaud, Bernard

    2017-09-18

    Lung diseases remain one of the main causes of morbidity and mortality in neonates. Cell therapy and regenerative medicine have the potential to revolutionize the management of life-threatening and debilitating lung diseases that currently lack effective treatments. Over the past decade, the repair capabilities of stem/progenitor cells has been harnessed to prevent/rescue lung damage in experimental neonatal lung diseases. Mesenchymal stromal cells and amnion epithelial cells exert pleiotropic effects and represent ideal therapeutic cells for bronchopulmonary dysplasia, a multifactorial disease. Endothelial progenitor cells are optimally suited to promote lung vascular growth and attenuate pulmonary hypertension in infants with congenital diaphragmatic hernia or a vascular bronchopulmonary dysplasia phenotype. Induced pluripotent stem cells (iPSCs) are one of the most exciting breakthroughs of the past decade. Patient-specific iPSCs can be derived from somatic cells and differentiated into any cell type. iPSCs can be capitalized upon to develop personalized regenerative cell products for surfactant protein deficiencies-lethal lung disorders without treatment-that affect a single gene in a single cell type and thus lend themselves to phenotype-specific cell replacement. While the clinical translation has begun, more needs to be learned about the biology of these repair cells to make this translation successful.Pediatric Research accepted article preview online, 18 September 2017. doi:10.1038/pr.2017.232.

  8. Biologic characteristics of fibroblast cells cultured from the knee ligaments

    Institute of Scientific and Technical Information of China (English)

    陈鸿辉; 唐毅; 李斯明; 沈雁; 刘向荣; 钟灿灿

    2002-01-01

    Objective: To culture fibroblast cells from the kneeligaments and to study the biological characteristics of thesecells.Methods: Cells of the anterior cruciate ligament(ACL) and the medial collateral ligament (MCL) fromNew Zealand white rabbit were cultured in vitro. Cellulargrowth and expression of the collagen were analyzed.Moreover, an in vitro wound closure model was establishedand the healing of the ACL and the MCL cells wascompared.Results: Maximal growth for all these cells wereobtained with Dulbecco's modified Eagle's mediumsupplemented with 10% fetal bovine serum, but RPMI 1640and Ham's F12 media were not suitable to maintain thesecells. Morphology of both ACL and MCL cells from NewZealand white rabbit was alike in vitro, but the MCL cellsgrew faster than the ACL cells. Both cell types producedsimilar amount of collagen in culture, but the ratio ofcollage type I to type III produced by ACL cells was higherthan that produced by MCL cells. Wound closure assayshowed that at 36 hours after injury, cell-free zones createdin the ACL cultures were occupied partially by the ACLcells; in contrast, the wounded zone in the MCL cultureswas almost completely covered by the cells.Conclusions: Although the ACL cells and the MCLcells from New Zealand white rabbit show similarappearance in morphology in culture, the cellular growthand the biochemical synthesis of collagen as well as thehealing in vitro were significantly different. Thesedifferences in intrinsic properties of the two types of cells invitro might contribute to the differential healing potentialsof these ligaments in vivo.

  9. Natural killer cells: Biology, functions and clinical relevance

    Directory of Open Access Journals (Sweden)

    Vojvodić Svetlana

    2010-01-01

    Full Text Available Introduction. Natural Killer cells (NK cells represent the subset of peripheral lymphocytes that play critical role in the innate immune response to virus-infected and tumor transformed cells. Lysis of NK sensitive target cells could be mediated independently of antigen stimulation and without requirement of peptide presentation by the major histocompatibility complex (MHC molecules. NK cell activity and functions are controlled by a considerable number of cell surface receptors, which exist in both inhibitory and activating isoforms. There are several groups of NK cell surface receptors: 1 killer immunoglobulin like receptors-KIR, 2 C-type lectin receptors,3natural citotoxicity receptors-NCR and 4 Toll-like receptors-TLR. Functions of NK receptors. Defining the biology of NK cell surface receptors has contributed to the concept of the manner how NK cells selectively recognize and lyse tumor and virally infected cells while sparing normal cells. Further, identification of NK receptor ligands and their expression on the normal and transformed cells has led to the development of clinical approaches to manipulating receptor/ligand interactions that showed clinical benefit. NK cells are the first lymphocyte subset that reconstitute the peripheral blood following allogeneic HSCT and multiple roles for alloreactive donor NK cells have been demonstrated, in diminishing Graft vs. Host Disease (GvHD through selective killing recipient dendritic cells, prevention of graft rejection by killing recipient T cells and participation in Graft vs. Leukaemia (GvL effect through destruction of residual host tumor cells. Conclusion. Besides their role in HSCT, NK cell receptors have an important clinical relevance that reflects from the fact that they play a crucial role in the development of some diseases as well as in possibilities of managing all NK receptors through selective expansion and usage of NK cells in cancer immunotherapy.

  10. Characterization of mast cell secretory granules and their cell biology.

    Science.gov (United States)

    Azouz, Nurit Pereg; Hammel, Ilan; Sagi-Eisenberg, Ronit

    2014-10-01

    Exocytosis and secretion of secretory granule (SG) contained inflammatory mediators is the primary mechanism by which mast cells exert their protective immune responses in host defense, as well as their pathological functions in allergic reactions and anaphylaxis. Despite their central role in mast cell function, the molecular mechanisms underlying the biogenesis and secretion of mast cell SGs remain largely unresolved. Early studies have established the lysosomal nature of the mast cell SGs and implicated SG homotypic fusion as an important step occurring during both their biogenesis and compound secretion. However, the molecular mechanisms that account for key features of this process largely remain to be defined. A novel high-resolution imaging based methodology allowed us to screen Rab GTPases for their phenotypic and functional impact and identify Rab networks that regulate mast cell secretion. This screen has identified Rab5 as a novel regulator of homotypic fusion of the mast cell SGs that thereby regulates their size and cargo composition.

  11. International Conference in Computational Cell Biology: From the Past to the Future

    Science.gov (United States)

    2016-09-12

    International Conference in Computational Cell Biology : from the past to the future The first International Conference on Computational Cell ...their latest research and discussed challenges in computational cell biology research and education. The views, opinions and/or findings contained in...International Conference in Computational Cell Biology : from the past to the future Report Title The first International Conference on Computational Cell

  12. Biochemical investigation and biological evaluation of the methanolic extract of the leaves of Nyctanthes arbortristis in vitro

    Institute of Scientific and Technical Information of China (English)

    Repon Kumer Saha; Srijan Acharya; Syed Sohidul Haque Shovon; Apurba Sarker Apu; Priyanka Roy

    2012-01-01

    Objective: Nyctanthes arbortristis is a common plant in Bangladesh. The objective of our research was to biochemical and biological analysis of the methanolic extract of the dried leaves of Nyctanthesarbortristis found in Bangladesh. Methods: We investigated the presence of polyphenols, flavanoids and other types of compounds by thin layer chromatography, infrared spectroscopy, and UV spectroscopy analysis. We performed antioxidant assay by colorimetric methods. We investigated antibacterial assay by disk diffusion method. Cell surface receptor binding assay was performed by hemagglutination inhibition assay and hemolysis assay. Results: Methanolic extract of the leaves of Nyctanthes arbortristis contains flavanoids and other biologically active compounds. The extract showed antioxidant, peroxide scavenging and total reducing activity. The extract also showed antibacterial activities against several strains of bacteria. It also showed hemaglutination inhibition activities and hydrogen peroxide induced hemolysis inhibition activity in human blood cells. Conclusions: Therefore, Nyctanthes arbortristis may be considered as a plant of various health benefits.

  13. The binding, transport and fate of aluminium in biological cells.

    Science.gov (United States)

    Exley, Christopher; Mold, Matthew J

    2015-04-01

    Aluminium is the most abundant metal in the Earth's crust and yet, paradoxically, it has no known biological function. Aluminium is biochemically reactive, it is simply that it is not required for any essential process in extant biota. There is evidence neither of element-specific nor evolutionarily conserved aluminium biochemistry. This means that there are no ligands or chaperones which are specific to its transport, there are no transporters or channels to selectively facilitate its passage across membranes, there are no intracellular storage proteins to aid its cellular homeostasis and there are no pathways which evolved to enable the metabolism and excretion of aluminium. Of course, aluminium is found in every compartment of every cell of every organism, from virus through to Man. Herein we have investigated each of the 'silent' pathways and metabolic events which together constitute a form of aluminium homeostasis in biota, identifying and evaluating as far as is possible what is known and, equally importantly, what is unknown about its uptake, transport, storage and excretion. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Differences in the primary culture, purification and biological characteristics between endothelial cells and smooth muscle cells from rat aorta

    Institute of Scientific and Technical Information of China (English)

    Shaobo Hu; Zifang Song; Qichang Zheng; Jun Nie

    2009-01-01

    Objective: To investigate the differences of primary culture, purification and biological characteristics between endothelial cells and smooth muscle cells from rat aorta. Methods: Endothelial cells were obtained using the vascular ring adherence, collagenase digestion method and an improved vascular ring adherence method, while smooth muscle cells were separated from tissue sections of rat aorta. Clones of endothelial cells were selected by limiting dilution assay. Both cell types were identified using specific cell immunofluorescent markers,and phase contrast microscopy was used to observe the morphological disparity between endothelial cells and smooth muscle cells at the single cell and colony level. Cell proliferation was determined by the cell counting kit-8. Differences between endothelial cells and smooth muscle cells were evaluated in trypsin digestion 6me, attachment time and recovery after cryopreservation. Results: Endothelial cells were obtained by all three methods. The improved vascular ring method provided the most reproducible results. Cells were in good condition, and of high purity. Smooth muscle cells were cultured successfully by the tissue fragment culture method. Clonal expansion of singleendothelial cells was attained. The two cell types expressed their respective specific markers, and the rate of proliferation of smooth muscle cells exceeded that of endothelial cells. Endothelial cells were more sensitive to trypsin digestion than smooth muscle cells. In addition, they had a shorter adherence time and better recovery following cryopreservation than smooth muscle cells. Conclusion: The improved vascular ring method was optimal for yielding endothelial cells. Limiting dilution is a novel and valid method for purifying primary endothelial cells from rat aorta. Primary rat endothelial cell and vascular smooth muscle cell cultures exhibited different morphological characteristics, proliferation rate, adherence time, susceptibility to trypsin

  15. Hydraulic fracturing in cells and tissues: fracking meets cell biology.

    Science.gov (United States)

    Arroyo, Marino; Trepat, Xavier

    2016-12-06

    The animal body is largely made of water. A small fraction of body water is freely flowing in blood and lymph, but most of it is trapped in hydrogels such as the extracellular matrix (ECM), the cytoskeleton, and chromatin. Besides providing a medium for biological molecules to diffuse, water trapped in hydrogels plays a fundamental mechanical role. This role is well captured by the theory of poroelasticity, which explains how any deformation applied to a hydrogel causes pressure gradients and water flows, much like compressing a sponge squeezes water out of it. Here we review recent evidence that poroelastic pressures and flows can fracture essential biological barriers such as the nuclear envelope, the cellular cortex, and epithelial layers. This type of fracture is known in engineering literature as hydraulic fracturing or 'fracking'.

  16. The cell biology of Tobacco mosaic virus replication and movement.

    Science.gov (United States)

    Liu, Chengke; Nelson, Richard S

    2013-01-01

    Successful systemic infection of a plant by Tobacco mosaic virus (TMV) requires three processes that repeat over time: initial establishment and accumulation in invaded cells, intercellular movement, and systemic transport. Accumulation and intercellular movement of TMV necessarily involves intracellular transport by complexes containing virus and host proteins and virus RNA during a dynamic process that can be visualized. Multiple membranes appear to assist TMV accumulation, while membranes, microfilaments and microtubules appear to assist TMV movement. Here we review cell biological studies that describe TMV-membrane, -cytoskeleton, and -other host protein interactions which influence virus accumulation and movement in leaves and callus tissue. The importance of understanding the developmental phase of the infection in relationship to the observed virus-membrane or -host protein interaction is emphasized. Utilizing the latest observations of TMV-membrane and -host protein interactions within our evolving understanding of the infection ontogeny, a model for TMV accumulation and intracellular spread in a cell biological context is provided.

  17. Bovine mammary stem cells: Cell biology meets production agriculture

    Science.gov (United States)

    Mammary stem cells (MaSC) provide for net growth, renewal and turnover of mammary epithelial cells, and are therefore potential targets for strategies to increase production efficiency. Appropriate regulation of MaSC can potentially benefit milk yield, persistency, dry period management and tissue ...

  18. Cell biology and genetics of minimal change disease.

    Science.gov (United States)

    Saleem, Moin A; Kobayashi, Yasuko

    2016-01-01

    Minimal change disease (MCD) is an important cause of nephrotic syndrome and is characterized by massive proteinuria and hypoalbuminemia, resulting in edema and hypercholesterolemia. The podocyte plays a key role in filtration and its disruption results in a dramatic loss of function leading to proteinuria. Immunologic disturbance has been suggested in the pathogenesis of MCD. Because of its clinical features, such as recurrent relapse/remission course, steroid response in most patients, and rare familial cases, a genetic defect has been thought to be less likely in MCD. Recent progress in whole-exome sequencing reveals pathogenic mutations in familial cases in steroid-sensitive nephrotic syndrome (SSNS) and sheds light on possible mechanisms and key molecules in podocytes in MCD. On the other hand, in the majority of cases, the existence of circulating permeability factors has been implicated along with T lymphocyte dysfunction. Observations of benefit with rituximab added B cell involvement to the disease. Animal models are unsatisfactory, and the humanized mouse may be a good model that well reflects MCD pathophysiology to investigate suggested "T cell dysfunction" directly related to podocytes in vivo. Several candidate circulating factors and their effects on podocytes have been proposed but are still not sufficient to explain whole mechanisms and clinical features in MCD. Another circulating factor disease is focal segmental glomerulosclerosis (FSGS), and it is not clear if this is a distinct entity, or on the same spectrum, implicating the same circulating factor(s). These patients are mostly steroid resistant and often have a rapid relapse after transplantation. In clinical practice, predicting relapse or disease activity and response to steroids is important and is an area where novel biomarkers can be developed based on our growing knowledge of podocyte signaling pathways. In this review, we discuss recent findings in genetics and podocyte biology in MCD.

  19. Cell biology and genetics of minimal change disease

    Science.gov (United States)

    Saleem, Moin A.; Kobayashi, Yasuko

    2016-01-01

    Minimal change disease (MCD) is an important cause of nephrotic syndrome and is characterized by massive proteinuria and hypoalbuminemia, resulting in edema and hypercholesterolemia. The podocyte plays a key role in filtration and its disruption results in a dramatic loss of function leading to proteinuria. Immunologic disturbance has been suggested in the pathogenesis of MCD. Because of its clinical features, such as recurrent relapse/remission course, steroid response in most patients, and rare familial cases, a genetic defect has been thought to be less likely in MCD. Recent progress in whole-exome sequencing reveals pathogenic mutations in familial cases in steroid-sensitive nephrotic syndrome (SSNS) and sheds light on possible mechanisms and key molecules in podocytes in MCD. On the other hand, in the majority of cases, the existence of circulating permeability factors has been implicated along with T lymphocyte dysfunction. Observations of benefit with rituximab added B cell involvement to the disease. Animal models are unsatisfactory, and the humanized mouse may be a good model that well reflects MCD pathophysiology to investigate suggested “T cell dysfunction” directly related to podocytes in vivo. Several candidate circulating factors and their effects on podocytes have been proposed but are still not sufficient to explain whole mechanisms and clinical features in MCD. Another circulating factor disease is focal segmental glomerulosclerosis (FSGS), and it is not clear if this is a distinct entity, or on the same spectrum, implicating the same circulating factor(s). These patients are mostly steroid resistant and often have a rapid relapse after transplantation. In clinical practice, predicting relapse or disease activity and response to steroids is important and is an area where novel biomarkers can be developed based on our growing knowledge of podocyte signaling pathways. In this review, we discuss recent findings in genetics and podocyte biology in

  20. Effects of fulvestrant on biological activity and Wnt expression in rat GH3 cells

    Institute of Scientific and Technical Information of China (English)

    Jiwei Bai; Yan Wang; Chuzhong Li; Yazhuo Zhang

    2012-01-01

    The present study investigated the influence of anti-estrogen treatment (fulvestrant) on pituitary adenoma cell line GH3 biological activity, the estrogen receptor α pathway, the WnT pathway, and mechanisms of decreased Wnt inhibitory factor-1 expression in GH3 cells. Results showed that fulvestrant suppressed GH3 cell proliferation and reduced hormone secretion in a dose-dependent manner. Estrogen receptor α and Wnt4 expression decreased, but Wnt inhibitory factor-1 expression increased in a dose-dependent manner following fulvestrant treatment, and β-catenin expression remained unchanged. Inhibitors of DNA methylation and histone modification upregulated Wnt inhibitory factor-1 expression. Results suggested that fulvestrant suppressed biological activity of GH3 cells via the estrogen receptor α and Wnt pathways. These results suggested that decreased Wnt inhibitory factor-1 expression in GH3 cells played a role in epigenetic mechanisms. Anti-estrogen therapies could provide novel treatments for growth hormone adenomas.

  1. Investigation of resins suitable for the preparation of biological sample for 3-D electron microscopy.

    Science.gov (United States)

    Kizilyaprak, Caroline; Longo, Giovanni; Daraspe, Jean; Humbel, Bruno M

    2015-02-01

    In the last two decades, the third-dimension has become a focus of attention in electron microscopy to better understand the interactions within subcellular compartments. Initially, transmission electron tomography (TEM tomography) was introduced to image the cell volume in semi-thin sections (∼ 500 nm). With the introduction of the focused ion beam scanning electron microscope, a new tool, FIB-SEM tomography, became available to image much larger volumes. During TEM tomography and FIB-SEM tomography, the resin section is exposed to a high electron/ion dose such that the stability of the resin embedded biological sample becomes an important issue. The shrinkage of a resin section in each dimension, especially in depth, is a well-known phenomenon. To ensure the dimensional integrity of the final volume of the cell, it is important to assess the properties of the different resins and determine the formulation which has the best stability in the electron/ion beam. Here, eight different resin formulations were examined. The effects of radiation damage were evaluated after different times of TEM irradiation. To get additional information on mass-loss and the physical properties of the resins (stiffness and adhesion), the topography of the irradiated areas was analysed with atomic force microscopy (AFM). Further, the behaviour of the resins was analysed after ion milling of the surface of the sample with different ion currents. In conclusion, two resin formulations, Hard Plus and the mixture of Durcupan/Epon, emerged that were considerably less affected and reasonably stable in the electron/ion beam and thus suitable for the 3-D investigation of biological samples.

  2. Cdc48: A Swiss Army Knife of Cell Biology

    Directory of Open Access Journals (Sweden)

    Guem Hee Baek

    2013-01-01

    Full Text Available Cdc48 (also called VCP and p97 is an abundant protein that plays essential regulatory functions in a broad array of cellular processes. Working with various cofactors, Cdc48 utilizes its ATPase activity to promote the assembly and disassembly of protein complexes. Here, we review key biological functions and regulation of Cdc48 in ubiquitin-related events. Given the broad employment of Cdc48 in cell biology and its intimate ties to human diseases (e.g., amyotrophic lateral sclerosis, studies of Cdc48 will bring significant insights into the mechanism and function of ubiquitin in health and diseases.

  3. Tensegrity I. Cell structure and hierarchical systems biology

    Science.gov (United States)

    Ingber, Donald E.

    2003-01-01

    In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular tensegrity model can now be revisited and placed in context of new advances in our understanding of cell structure, biological networks and mechanoregulation that have been made over the past decade. Recent work provides strong evidence to support the use of tensegrity by cells, and mathematical formulations of the model predict many aspects of cell behavior. In addition, development of the tensegrity theory and its translation into mathematical terms are beginning to allow us to define the relationship between mechanics and biochemistry at the molecular level and to attack the larger problem of biological complexity. Part I of this two-part article covers the evidence for cellular tensegrity at the molecular level and describes how this building system may provide a structural basis for the hierarchical organization of living systems--from molecule to organism. Part II, which focuses on how these structural networks influence information processing networks, appears in the next issue.

  4. Tensegrity I. Cell structure and hierarchical systems biology

    Science.gov (United States)

    Ingber, Donald E.

    2003-01-01

    In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular tensegrity model can now be revisited and placed in context of new advances in our understanding of cell structure, biological networks and mechanoregulation that have been made over the past decade. Recent work provides strong evidence to support the use of tensegrity by cells, and mathematical formulations of the model predict many aspects of cell behavior. In addition, development of the tensegrity theory and its translation into mathematical terms are beginning to allow us to define the relationship between mechanics and biochemistry at the molecular level and to attack the larger problem of biological complexity. Part I of this two-part article covers the evidence for cellular tensegrity at the molecular level and describes how this building system may provide a structural basis for the hierarchical organization of living systems--from molecule to organism. Part II, which focuses on how these structural networks influence information processing networks, appears in the next issue.

  5. Influence of age on the cell biological characteristics and the stimulation potential of male human tenocyte-like cells

    Directory of Open Access Journals (Sweden)

    F Klatte-Schulz

    2012-07-01

    Full Text Available The incidence of rotator cuff tears and recurrent defects positively correlate with patient age. However, this observation has never been analysed at the cellular level. The present study aims to better understand this correlation by investigating cellular characteristics of rotator cuff tenocytes of different age groups. Additionally, previous studies reported on stimulating effects of Bone Morphogenetic Protein (BMP -2 and BMP-7 on tenocytes. Thus, the second aim was to investigate, whether the stimulation potential of tenocytes demonstrates age-related differences.Tenocyte-like cells from supraspinatus tendons of young and aged patients were analysed for the following cell biological characteristics: cell density, cell growth, marker expression, collagen-I protein synthesis, stem cell phenotype, potential for multipotent differentiation and self-renewal. To analyse the stimulation potential, cells were treated with BMP-2 and BMP-7 in 2D-/3D-cultures. Measured parameters included cell activity, marker expression and collagen-I protein synthesis.An effect of age was seen for cell growth and stem cell potential but not on extracellular matrix level. Cells from both groups responded to BMP-7 by increasing cell activity, collagen-I expression and protein synthesis. BMP-2 led to smaller increases in these parameters when compared to BMP-7. In general, 3D-cultivation improved the stimulation compared to 2D-culture.The cell biological characteristics of tenocyte-like cells, considered important for successful restoration of the tendon-bone unit, were inferior in elderly donors. This may help explain higher rates of recurrent defects seen in elderly patients. Regarding the stimulation potential, on a cellular level young and aged patients may benefit from biological augmentation with BMPs.

  6. Biological Effects of Osteoblast-Like Cells on Nanohydroxyapatite Particles at a Low Concentration Range

    OpenAIRE

    Xiaochen Liu; Jie Wei; Shicheng Wei

    2011-01-01

    The biological effects of osteoblast-like MG-63 cells on nanohydroxyapatite (n-HA) at the low concentration range (5–25  g/mL) for 5 days was investigated. The results showed the viability and actin cytoskeleton of the cells descended with the increase of the concentration of n-HA, and the actin cytoskeleton of cells was depolymerised and became more disordered. Apoptotic rate of cells (1.85%, 1.99%, and 2.29%) increased with the increase of n-HA concentration (5, 15, and 25  g/mL) and be...

  7. Systematically biological prioritizing remediation sites based on datasets of biological investigations and heavy metals in soil

    Science.gov (United States)

    Lin, Wei-Chih; Lin, Yu-Pin; Anthony, Johnathen

    2015-04-01

    Heavy metal pollution has adverse effects on not only the focal invertebrate species of this study, such as reduction in pupa weight and increased larval mortality, but also on the higher trophic level organisms which feed on them, either directly or indirectly, through the process of biomagnification. Despite this, few studies regarding remediation prioritization take species distribution or biological conservation priorities into consideration. This study develops a novel approach for delineating sites which are both contaminated by any of 5 readily bioaccumulated heavy metal soil contaminants and are of high ecological importance for the highly mobile, low trophic level focal species. The conservation priority of each site was based on the projected distributions of 6 moth species simulated via the presence-only maximum entropy species distribution model followed by the subsequent application of a systematic conservation tool. In order to increase the number of available samples, we also integrated crowd-sourced data with professionally-collected data via a novel optimization procedure based on a simulated annealing algorithm. This integration procedure was important since while crowd-sourced data can drastically increase the number of data samples available to ecologists, still the quality or reliability of crowd-sourced data can be called into question, adding yet another source of uncertainty in projecting species distributions. The optimization method screens crowd-sourced data in terms of the environmental variables which correspond to professionally-collected data. The sample distribution data was derived from two different sources, including the EnjoyMoths project in Taiwan (crowd-sourced data) and the Global Biodiversity Information Facility (GBIF) ?eld data (professional data). The distributions of heavy metal concentrations were generated via 1000 iterations of a geostatistical co-simulation approach. The uncertainties in distributions of the heavy

  8. Extracellular Vesicles: Evolving Factors in Stem Cell Biology

    Science.gov (United States)

    Nawaz, Muhammad; Fatima, Farah; Vallabhaneni, Krishna C.; Penfornis, Patrice; Valadi, Hadi; Ekström, Karin; Kholia, Sharad; Whitt, Jason D.; Fernandes, Joseph D.; Pochampally, Radhika; Squire, Jeremy A.; Camussi, Giovanni

    2016-01-01

    Stem cells are proposed to continuously secrete trophic factors that potentially serve as mediators of autocrine and paracrine activities, associated with reprogramming of the tumor microenvironment, tissue regeneration, and repair. Hitherto, significant efforts have been made to understand the level of underlying paracrine activities influenced by stem cell secreted trophic factors, as little is known about these interactions. Recent findings, however, elucidate this role by reporting the effects of stem cell derived extracellular vesicles (EVs) that mimic the phenotypes of the cells from which they originate. Exchange of genetic information utilizing persistent bidirectional communication mediated by stem cell-EVs could regulate stemness, self-renewal, and differentiation in stem cells and their subpopulations. This review therefore discusses stem cell-EVs as evolving communication factors in stem cell biology, focusing on how they regulate cell fates by inducing persistent and prolonged genetic reprogramming of resident cells in a paracrine fashion. In addition, we address the role of stem cell-secreted vesicles in shaping the tumor microenvironment and immunomodulation and in their ability to stimulate endogenous repair processes during tissue damage. Collectively, these functions ensure an enormous potential for future therapies. PMID:26649044

  9. Sorting and biological characteristics analysis for side population cells in human primary hepatocellular carcinoma

    Science.gov (United States)

    Jiang, Yegui; Gao, Hucheng; Liu, Mingdong; Mao, Qing

    2016-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cause of the tumor worldwide, its incidence is increasing year by year. This study aims to investigate the sorting and biological characteristics of side population (SP) cells. Human HCC tissues used were obtained from patients undergoing surgical resection. SP cells were sorted using flow cytometry. Cell cycle assay, apoptosis assay and colony formation assay were performed to detect cell proliferation and apoptosis. Invasion assay was employed to examine SP cell invasion. Tumorigenicity assay was used to evaluate tumorigenicity. HCC related microRNAs (miRNA) were analyzed using Micro-array analysis. Target genes were predicted using miRNA database. GO analsis was employed to predict target gene function. Apoptosis percentage was lower and cell viability was higher in SP cells than non-SP (NSP) cells. Colony forming ability of SP cells was significantly higher than NSP cells. Transwell assay positive cells in SP cells were higher significantly than NSP cells. Tumorigenicity of SP cells was higher significantly than NSP cells. 107 differentially expression miRNA were discovered, including 45 up-expressed miRNAs and 62 down-expressed miRNAs in SP cells. Up-regulated hsa-miR-193b-3p and hsa-miR-505-3p predict 25 and 35 target genes, and correlated with 4 and 42 GO terms, respectively. Down-regulated hsa-miR-200a-3p, hsa-miR-194-5p, hsa-miR-130b-3p predict 133, 48 and 127 target genes, and correlate with 10, 7 and 109 GO terms, respectively. In conclusion, proliferation, colony formation, anti-apoptosis, self-renewal capavility, invasive characteristic and tumorigenicity in SP cells isolated from HCC tissues was higher compared to NSP cells. Therefore, sorted SP cells could characterize with biological functions of cancer stem cells.

  10. Multiway modeling and analysis in stem cell systems biology

    Directory of Open Access Journals (Sweden)

    Vandenberg Scott L

    2008-07-01

    Full Text Available Abstract Background Systems biology refers to multidisciplinary approaches designed to uncover emergent properties of biological systems. Stem cells are an attractive target for this analysis, due to their broad therapeutic potential. A central theme of systems biology is the use of computational modeling to reconstruct complex systems from a wealth of reductionist, molecular data (e.g., gene/protein expression, signal transduction activity, metabolic activity, etc.. A number of deterministic, probabilistic, and statistical learning models are used to understand sophisticated cellular behaviors such as protein expression during cellular differentiation and the activity of signaling networks. However, many of these models are bimodal i.e., they only consider row-column relationships. In contrast, multiway modeling techniques (also known as tensor models can analyze multimodal data, which capture much more information about complex behaviors such as cell differentiation. In particular, tensors can be very powerful tools for modeling the dynamic activity of biological networks over time. Here, we review the application of systems biology to stem cells and illustrate application of tensor analysis to model collagen-induced osteogenic differentiation of human mesenchymal stem cells. Results We applied Tucker1, Tucker3, and Parallel Factor Analysis (PARAFAC models to identify protein/gene expression patterns during extracellular matrix-induced osteogenic differentiation of human mesenchymal stem cells. In one case, we organized our data into a tensor of type protein/gene locus link × gene ontology category × osteogenic stimulant, and found that our cells expressed two distinct, stimulus-dependent sets of functionally related genes as they underwent osteogenic differentiation. In a second case, we organized DNA microarray data in a three-way tensor of gene IDs × osteogenic stimulus × replicates, and found that application of tensile strain to a

  11. Biology and relevance of human acute myeloid leukemia stem cells.

    Science.gov (United States)

    Thomas, Daniel; Majeti, Ravindra

    2017-03-23

    Evidence of human acute myeloid leukemia stem cells (AML LSCs) was first reported nearly 2 decades ago through the identification of rare subpopulations of engrafting cells in xenotransplantation assays. These AML LSCs were shown to reside at the apex of a cellular hierarchy that initiates and maintains the disease, exhibiting properties of self-renewal, cell cycle quiescence, and chemoresistance. This cancer stem cell model offers an explanation for chemotherapy resistance and disease relapse and implies that approaches to treatment must eradicate LSCs for cure. More recently, a number of studies have both refined and expanded our understanding of LSCs and intrapatient heterogeneity in AML using improved xenotransplant models, genome-scale analyses, and experimental manipulation of primary patient cells. Here, we review these studies with a focus on the immunophenotype, biological properties, epigenetics, genetics, and clinical associations of human AML LSCs and discuss critical questions that need to be addressed in future research. © 2017 by The American Society of Hematology.

  12. Engineering Therapeutic T Cells: From Synthetic Biology to Clinical Trials.

    Science.gov (United States)

    Esensten, Jonathan H; Bluestone, Jeffrey A; Lim, Wendell A

    2017-01-24

    Engineered T cells are currently in clinical trials to treat patients with cancer, solid organ transplants, and autoimmune diseases. However, the field is still in its infancy. The design, and manufacturing, of T cell therapies is not standardized and is performed mostly in academic settings by competing groups. Reliable methods to define dose and pharmacokinetics of T cell therapies need to be developed. As of mid-2016, there are no US Food and Drug Administration (FDA)-approved T cell therapeutics on the market, and FDA regulations are only slowly adapting to the new technologies. Further development of engineered T cell therapies requires advances in immunology, synthetic biology, manufacturing processes, and government regulation. In this review, we outline some of these challenges and discuss the contributions that pathologists can make to this emerging field.

  13. The 'omics revolution and our understanding of sperm cell biology

    Institute of Scientific and Technical Information of China (English)

    Mark A Baker

    2011-01-01

    The foundations of proteomics are to study gene products and their regulatory roles within cells. Paradoxically, the only evidence that sperm cells make new proteins is through mitochondrial protein synthesis. Yet despite this, spermatozoa are the perfect candidates for mass spectrometry and hence, proteomic analysis. These enterprising cells use a plethora of post-translational modifications in order to gain functionality following their production within the testis. By using a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and more recently liquid chromatography-mass spectrometry (LC-MS)/MS, recent advances in sperm cell biology, through the use of proteomics, is making unparalleled progress. The protein inventory lists being generated have shed light on transmembrane proteins, kinases and chaperones never previously recognized. In addition, the ability to isolate either phosphopeptides or glycopeptides and quantify the differences between cells of two different populations make proteomic analysis of spermatozoa a real chance to finally answer some age old questions.

  14. Simulated weightlessness alters biological characteristics of human breast cancer cell line MCF-7

    Science.gov (United States)

    Qian, Airong; Zhang, Wei; Xie, Li; Weng, Yuanyuan; Yang, Pengfei; Wang, Zhe; Hu, Lifang; Xu, Huiyun; Tian, Zongcheng; Shang, Peng

    The aim of this study is to investigate the effects of the clinostat-simulated microgravity on MCF-7 cells (a breast cancer cell line) biological characteristics. MCF-7 cells were incubated for 24 h in an incubator and then rotated in a clinostat as a model of simulated microgravity for 24, 48 and 72 h, respectively. The effects of the clinostat-simulated microgravity on MCF-7 cells proliferation, invasion, migration, gelatinase production, adhesion, cell cycle, apoptosis and vinculin expression were detected. The results showed that the clinostat-simulated microgravity affected breast cancer cell invasion, migration, adhesion, cell cycle, cell apoptosis and vinculin expression. These results may explore a new field of vision to study tumor metastasis in future.

  15. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    Directory of Open Access Journals (Sweden)

    Matthew Emerson Randolph

    2015-10-01

    Full Text Available The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some muscular dystrophies. The biology of muscle stem cells varies depending on their embryologic origins and the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease.

  16. High-Content Screening for Quantitative Cell Biology.

    Science.gov (United States)

    Mattiazzi Usaj, Mojca; Styles, Erin B; Verster, Adrian J; Friesen, Helena; Boone, Charles; Andrews, Brenda J

    2016-08-01

    High-content screening (HCS), which combines automated fluorescence microscopy with quantitative image analysis, allows the acquisition of unbiased multiparametric data at the single cell level. This approach has been used to address diverse biological questions and identify a plethora of quantitative phenotypes of varying complexity in numerous different model systems. Here, we describe some recent applications of HCS, ranging from the identification of genes required for specific biological processes to the characterization of genetic interactions. We review the steps involved in the design of useful biological assays and automated image analysis, and describe major challenges associated with each. Additionally, we highlight emerging technologies and future challenges, and discuss how the field of HCS might be enhanced in the future.

  17. The cell biology of lignification in higher plants.

    Science.gov (United States)

    Barros, Jaime; Serk, Henrik; Granlund, Irene; Pesquet, Edouard

    2015-06-01

    Lignin is a polyphenolic polymer that strengthens and waterproofs the cell wall of specialized plant cell types. Lignification is part of the normal differentiation programme and functioning of specific cell types, but can also be triggered as a response to various biotic and abiotic stresses in cells that would not otherwise be lignifying. Cell wall lignification exhibits specific characteristics depending on the cell type being considered. These characteristics include the timing of lignification during cell differentiation, the palette of associated enzymes and substrates, the sub-cellular deposition sites, the monomeric composition and the cellular autonomy for lignin monomer production. This review provides an overview of the current understanding of lignin biosynthesis and polymerization at the cell biology level. The lignification process ranges from full autonomy to complete co-operation depending on the cell type. The different roles of lignin for the function of each specific plant cell type are clearly illustrated by the multiple phenotypic defects exhibited by knock-out mutants in lignin synthesis, which may explain why no general mechanism for lignification has yet been defined. The range of phenotypic effects observed include altered xylem sap transport, loss of mechanical support, reduced seed protection and dispersion, and/or increased pest and disease susceptibility. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. 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.

  19. Synthetic biology of minimal living cells: primitive cell models and semi-synthetic cells.

    Science.gov (United States)

    Stano, Pasquale

    2010-09-01

    This article summarizes a contribution presented at the ESF 2009 Synthetic Biology focused on the concept of the minimal requirement for life and on the issue of constructive (synthetic) approaches in biological research. The attempts to define minimal life within the framework of autopoietic theory are firstly described, and a short report on the development of autopoietic chemical systems based on fatty acid vesicles, which are relevant as primitive cell models is given. These studies can be used as a starting point for the construction of more complex systems, firstly being inspired by possible origins of life scenarioes (and therefore by considering primitive functions), then by considering an approach based on modern biomacromolecular-encoded functions. At this aim, semi-synthetic minimal cells are defined as those man-made vesicle-based systems that are composed of the minimal number of genes, proteins, biomolecules and which can be defined as living. Recent achievements on minimal sized semi-synthetic cells are then discussed, and the kind of information obtained is recognized as being distinctively derived by a constructive approach. Synthetic biology is therefore a fundamental tool for gaining basic knowledge about biosystems, and it should not be confined at all to the engineering side.

  20. New frontiers in human cell biology and medicine: can pluripotent stem cells deliver?

    Science.gov (United States)

    Goldstein, Lawrence S B

    2012-11-12

    Human pluripotent stem cells provide enormous opportunities to treat disease using cell therapy. But human stem cells can also drive biomedical and cell biological discoveries in a human model system, which can be directly linked to understanding disease or developing new therapies. Finally, rigorous scientific studies of these cells can and should inform the many science and medical policy issues that confront the translation of these technologies to medicine. In this paper, I discuss these issues using amyotrophic lateral sclerosis as an example.

  1. 100 years after Smoluchowski: stochastic processes in cell biology

    Science.gov (United States)

    Holcman, D.; Schuss, Z.

    2017-03-01

    100 years after Smoluchowski introduced his approach to stochastic processes, they are now at the basis of mathematical and physical modeling in cellular biology: they are used for example to analyse and to extract features from a large number (tens of thousands) of single molecular trajectories or to study the diffusive motion of molecules, proteins or receptors. Stochastic modeling is a new step in large data analysis that serves extracting cell biology concepts. We review here Smoluchowski’s approach to stochastic processes and provide several applications for coarse-graining diffusion, studying polymer models for understanding nuclear organization and finally, we discuss the stochastic jump dynamics of telomeres across cell division and stochastic gene regulation.

  2. New Developments in Mast Cell Biology: Clinical Implications.

    Science.gov (United States)

    Arthur, Greer; Bradding, Peter

    2016-09-01

    Mast cells (MCs) are present in connective tissue and at mucosal surfaces in all classes of vertebrates. In health, they contribute to tissue homeostasis, host defense, and tissue repair via multiple receptors regulating the release of a vast stockpile of proinflammatory mediators, proteases, and cytokines. However, these potentially protective cells are a double-edged sword. When there is a repeated or long-term stimulus, MC activation leads to tissue damage and dysfunction. Accordingly, MCs are implicated in the pathophysiologic aspects of numerous diseases covering all organs. Understanding the biology of MCs, their heterogeneity, mechanisms of activation, and signaling cascades may lead to the development of novel therapies for many diseases for which current treatments are lacking or are of poor efficacy. This review will focus on updates and developments in MC biology and their clinical implications, with a particular focus on their role in respiratory diseases.

  3. Membrane curvature in cell biology: An integration of molecular mechanisms.

    Science.gov (United States)

    Jarsch, Iris K; Daste, Frederic; Gallop, Jennifer L

    2016-08-15

    Curving biological membranes establishes the complex architecture of the cell and mediates membrane traffic to control flux through subcellular compartments. Common molecular mechanisms for bending membranes are evident in different cell biological contexts across eukaryotic phyla. These mechanisms can be intrinsic to the membrane bilayer (either the lipid or protein components) or can be brought about by extrinsic factors, including the cytoskeleton. Here, we review examples of membrane curvature generation in animals, fungi, and plants. We showcase the molecular mechanisms involved and how they collaborate and go on to highlight contexts of curvature that are exciting areas of future research. Lessons from how membranes are bent in yeast and mammals give hints as to the molecular mechanisms we expect to see used by plants and protists.

  4. Identification of biologically relevant enhancers in human erythroid cells.

    Science.gov (United States)

    Su, Mack Y; Steiner, Laurie A; Bogardus, Hannah; Mishra, Tejaswini; Schulz, Vincent P; Hardison, Ross C; Gallagher, Patrick G

    2013-03-22

    Identification of cell type-specific enhancers is important for understanding the regulation of programs controlling cellular development and differentiation. Enhancers are typically marked by the co-transcriptional activator protein p300 or by groups of cell-expressed transcription factors. We hypothesized that a unique set of enhancers regulates gene expression in human erythroid cells, a highly specialized cell type evolved to provide adequate amounts of oxygen throughout the body. Using chromatin immunoprecipitation followed by massively parallel sequencing, genome-wide maps of candidate enhancers were constructed for p300 and four transcription factors, GATA1, NF-E2, KLF1, and SCL, using primary human erythroid cells. These data were combined with gene expression analyses, and candidate enhancers were identified. Consistent with their predicted function as candidate enhancers, there was statistically significant enrichment of p300 and combinations of co-localizing erythroid transcription factors within 1-50 kb of the transcriptional start site (TSS) of genes highly expressed in erythroid cells. Candidate enhancers were also enriched near genes with known erythroid cell function or phenotype. Candidate enhancers exhibited moderate conservation with mouse and minimal conservation with nonplacental vertebrates. Candidate enhancers were mapped to a set of erythroid-associated, biologically relevant, SNPs from the genome-wide association studies (GWAS) catalogue of NHGRI, National Institutes of Health. Fourteen candidate enhancers, representing 10 genetic loci, mapped to sites associated with biologically relevant erythroid traits. Fragments from these loci directed statistically significant expression in reporter gene assays. Identification of enhancers in human erythroid cells will allow a better understanding of erythroid cell development, differentiation, structure, and function and provide insights into inherited and acquired hematologic disease.

  5. Skeletal muscle stem cells from animals I. Basic cell biology

    Science.gov (United States)

    Skeletal muscle stem cells from food-producing animals have been of interest to agricultural life scientists seeking to develop a better understanding of the molecular regulation of lean tissue (skeletal muscle protein hypertrophy) and intramuscular fat (marbling) development. Enhanced understanding...

  6. Metastasis in renal cell carcinoma: Biology and implications for therapy

    Directory of Open Access Journals (Sweden)

    Jun Gong

    2016-10-01

    Full Text Available Although multiple advances have been made in systemic therapy for renal cell carcinoma (RCC, metastatic RCC remains incurable. In the current review, we focus on the underlying biology of RCC and plausible mechanisms of metastasis. We further outline evolving strategies to combat metastasis through adjuvant therapy. Finally, we discuss clinical patterns of metastasis in RCC and how distinct systemic therapy approaches may be considered based on the anatomic location of metastasis.

  7. Nanodomain stabilization dynamics in plasma membranes of biological cells

    Science.gov (United States)

    Das, Tamal; Maiti, Tapas K.; Chakraborty, Suman

    2011-02-01

    We discover that a synergistically amplifying role of stabilizing membrane proteins and continuous lipid recycling can explain the physics governing the stability, polydispersity, and dynamics of lipid raft domains in plasma membranes of biological cells. We establish the conjecture using a generalized order parameter based on theoretical formalism, endorsed by detailed scaling arguments and domain mapping. Quantitative agreements with morphological distributions of raft complexes, as obtained from Förster resonance energy transfer based visualization, support the present theoretical conjecture.

  8. In focus: molecular and cell biology research in China.

    Science.gov (United States)

    Yao, Xuebiao; Li, Dangsheng; Pei, Gang

    2013-09-01

    An interactive, intellectual environment with good funding opportunities is essential for the development and success of basic research. The fast-growing economy and investment in science, together with a visionary plan, have attracted foreign scholars to work in China, motivated world-class Chinese scientists to return and strengthened the country's international collaborations. As a result, molecular and cell biology research in China has evolved rapidly over the past decade.

  9. A short guide to technology development in cell biology.

    Science.gov (United States)

    van Steensel, Bas

    2015-03-16

    New technologies drive progress in many research fields, including cell biology. Much of technological innovation comes from "bottom-up" efforts by individual students and postdocs. However, technology development can be challenging, and a successful outcome depends on many factors. This article outlines some considerations that are important when embarking on a technology development project. Despite the challenges, developing a new technology can be extremely rewarding and could lead to a lasting impact in a given field.

  10. [Effects of decitabine on biological behavior of U266 cells].

    Science.gov (United States)

    Wang, Mei-Fang; Yang, Lin-Hua; Dong, Chun-Xia; Zhang, Rui-Juan; Zhang, Jian-Hua; Guo, Zhi-Ping; Chen, Jian-Fang; Zhagn, Li; Feng, Da-Wei

    2011-08-01

    This study was aimed to explore the effects of decitabine on the biological behaviour of U266 cells in vitro so as to provide a new thinking and experiment basis, as well as new evidences for the pathogenesis of multiple myeloma. MTT and colony formation assays were used to evaluate the impact of decitabine on the ability of proliferation of U266 cells; flow cytometry was used to analyze the cell distribution in cell cycle; transwell chamber and matrigel assays were used to observe the ability of migration and invasion. The results indicated that decitabine could significantly suppress the proliferation of U266 cells in time-and dose-dependent manners. The flow cytometric analysis demonstrated that the cells in G(0)-G(1) phase significantly increased while the cells in S and G(2)/M phase decreased. The migration and matrigel invading tests showed that the number of cells moving into under chamber of transwell decreased after U266 cells treated with decitabine. It is concluded that decitabine may act as an effective drug for MM by inhibiting the proliferation, migration and invasion ability, and the specific mechanism needs to be deeply explored.

  11. A unified cell biological perspective on axon-myelin injury.

    Science.gov (United States)

    Simons, Mikael; Misgeld, Thomas; Kerschensteiner, Martin

    2014-08-04

    Demyelination and axon loss are pathological hallmarks of the neuroinflammatory disorder multiple sclerosis (MS). Although we have an increasingly detailed understanding of how immune cells can damage axons and myelin individually, we lack a unified view of how the axon-myelin unit as a whole is affected by immune-mediated attack. In this review, we propose that as a result of the tight cell biological interconnection of axons and myelin, damage to either can spread, which might convert a local inflammatory disease process early in MS into the global progressive disorder seen during later stages. This mode of spreading could also apply to other neurological disorders.

  12. Topological Quantum Computation and Error Correction by Biological Cells

    CERN Document Server

    Lofthouse, J T

    2005-01-01

    A Topological examination of phospholipid dynamics in the Far from Equilibrium state has demonstrated that metabolically active cells use waste heat to generate spatially patterned membrane flows by forced convection and shear. This paper explains the resemblance between this nonlinear membrane model and Witten Kitaev type Topological Quantum Computation systems, and demonstrates how this self-organising membrane enables biological cells to circumvent the decoherence problem, perform error correction procedures, and produce classical level output as shielded current flow through cytoskeletal protein conduit. Cellular outputs are shown to be Turing compatible as they are determined by computable in principle hydromagnetic fluid flows, and importantly, are Adaptive from an Evolutionary perspective.

  13. A new view into prokaryotic cell biology from electron cryotomography.

    Science.gov (United States)

    Oikonomou, Catherine M; Jensen, Grant J

    2016-04-01

    Electron cryotomography (ECT) enables intact cells to be visualized in 3D in an essentially native state to 'macromolecular' (∼4 nm) resolution, revealing the basic architectures of complete nanomachines and their arrangements in situ. Since its inception, ECT has advanced our understanding of many aspects of prokaryotic cell biology, from morphogenesis to subcellular compartmentalization and from metabolism to complex interspecies interactions. In this Review, we highlight how ECT has provided structural and mechanistic insights into the physiology of bacteria and archaea and discuss prospects for the future.

  14. Plant Cell and Signaling Biology Blooms in the Wuyi Mountain

    Institute of Scientific and Technical Information of China (English)

    Jianping Hu

    2011-01-01

    @@ INTRODUCTION The Eighth International Conference on Plant Biology Fron-tiers, organized by Zhenbiao Yang, Chentao Lin, and Xing-wang Deng, was convened in the Wuyi Mountain Yeohwa Resort in Fujian, China, 23-27 September 2010.The meeting's main theme was Cells and Signals, featuring four keynote speeches, 45 plenary talks, and over 40 poster presentations that covered a wide range of topics, from dynamic cellular structures to how developmental and environmental signals control various plant processes at the juncture of cells.

  15. Using Molecular Biology to Develop Drugs for Renal Cell Carcinoma

    Science.gov (United States)

    Cowey, C. Lance; Rathmell, W. Kimryn

    2010-01-01

    Background Renal cell carcinoma is a disease marked by a unique biology which has governed it’s long history of poor response to conventional cancer treatments. The discovery of the signaling pathway activated as a result of inappropriate constitutive activation of the hypoxia inducible factors (HIF), transcription factors physiologically and transiently stabilized in response to low oxygen, has provided a primary opportunity to devise treatment strategies to target this oncogenic pathway. Objective A review of the molecular pathogenesis of renal cell cancer as well as molecularly targeted therapies, both those currently available and those in development, will be provided. In addition, trials involving combination or sequential targeted therapy are discussed. Methods A detailed review of the literature describing the molecular biology of renal cell cancer and novel therapies was performed and summarized. Results/Conclusion Therapeutics targeting angiogenesis have provided the first class of agents which provide clinical benefit in a large majority of patients and heralded renal cell carcinoma as a solid tumor paradigm for the development of novel therapeutics. Multiple strategies targeting this pathway and now other identified pathways in renal cell carcinoma provide numerous potential opportunities to make major improvements in treating this historically devastating cancer. PMID:20648240

  16. Induced Pluripotent Stem Cell Technology in Regenerative Medicine and Biology

    Science.gov (United States)

    Pei, Duanqing; Xu, Jianyong; Zhuang, Qiang; Tse, Hung-Fat; Esteban, Miguel A.

    The potential of human embryonic stem cells (ESCs) for regenerative medicine is unquestionable, but practical and ethical considerations have hampered clinical application and research. In an attempt to overcome these issues, the conversion of somatic cells into pluripotent stem cells similar to ESCs, commonly termed nuclear reprogramming, has been a top objective of contemporary biology. More than 40 years ago, King, Briggs, and Gurdon pioneered somatic cell nuclear reprogramming in frogs, and in 1981 Evans successfully isolated mouse ESCs. In 1997 Wilmut and collaborators produced the first cloned mammal using nuclear transfer, and then Thomson obtained human ESCs from in vitro fertilized blastocysts in 1998. Over the last 2 decades we have also seen remarkable findings regarding how ESC behavior is controlled, the importance of which should not be underestimated. This knowledge allowed the laboratory of Shinya Yamanaka to overcome brilliantly conceptual and technical barriers in 2006 and generate induced pluripotent stem cells (iPSCs) from mouse fibroblasts by overexpressing defined combinations of ESC-enriched transcription factors. Here, we discuss some important implications of human iPSCs for biology and medicine and also point to possible future directions.

  17. Theories and models on the biological of cells in space

    Science.gov (United States)

    Todd, P.; Klaus, D. M.

    1996-01-01

    A wide variety of observations on cells in space, admittedly made under constraining and unnatural conditions in may cases, have led to experimental results that were surprising or unexpected. Reproducibility, freedom from artifacts, and plausibility must be considered in all cases, even when results are not surprising. The papers in symposium on 'Theories and Models on the Biology of Cells in Space' are dedicated to the subject of the plausibility of cellular responses to gravity -- inertial accelerations between 0 and 9.8 m/sq s and higher. The mechanical phenomena inside the cell, the gravitactic locomotion of single eukaryotic and prokaryotic cells, and the effects of inertial unloading on cellular physiology are addressed in theoretical and experimental studies.

  18. Theories and models on the Biology of Cells in Space

    Science.gov (United States)

    Todd, P.; Klaus, D. M.

    A wide variety of observations on cells in space, admittedly made under constraining and unnatural conditions in many cases, have led to experimental results that were surprising or unexpected. Reproducibility, freedom from artifacts, and plausibility must be considered in all cases, even when results are not surprising. The papers in the symposium on ``Theories and Models on the Biology of Cells in Space'' are dedicated to the subject of theplausibility of cellular responses to gravity -- inertial accelerations between 0 and 9.8 m/s^2 and higher. The mechanical phenomena inside the cell, the gravitactic locomotion of single eukaryotic and prokaryotic cells, and the effects of inertial unloading on cellular physiology are addressed in theoretical and experimental studies.

  19. Synthesis and Biological Investigation of Δ(12)-Prostaglandin J3 (Δ(12)-PGJ3) Analogues and Related Compounds.

    Science.gov (United States)

    Nicolaou, K C; Pulukuri, Kiran Kumar; Rigol, Stephan; Heretsch, Philipp; Yu, Ruocheng; Grove, Charles I; Hale, Christopher R H; ElMarrouni, Abdelatif; Fetz, Verena; Brönstrup, Mark; Aujay, Monette; Sandoval, Joseph; Gavrilyuk, Julia

    2016-05-25

    A series of Δ(12)-prostaglandin J3 (Δ(12)-PGJ3) analogues and derivatives were synthesized employing an array of synthetic strategies developed specifically to render them readily available for biological investigations. The synthesized compounds were evaluated for their cytotoxicity against a number of cancer cell lines, revealing nanomolar potencies for a number of them against certain cancer cell lines. Four analogues (2, 11, 21, and 27) demonstrated inhibition of nuclear export through a covalent addition at Cys528 of the export receptor Crm1. One of these compounds (i.e., 11) is currently under evaluation as a potential drug candidate for the treatment of certain types of cancer. These studies culminated in useful and path-pointing structure-activity relationships (SARs) that provide guidance for further improvements in the biological/pharmacological profiles of compounds within this class.

  20. Investigation on the Isolation and Biological Characteristics of Bone Marrow Mesenchymal Stem Cells of ICR Mice%ICR小鼠骨髓间充质干细胞分离及生物学特性的探讨

    Institute of Scientific and Technical Information of China (English)

    杨超; 辛娜; 康炜; 卢韬; 董学君

    2016-01-01

    目的 探讨分离、培养的ICR(Institute of Cancer Research,ICR)小鼠骨髓间充质干细胞(mouse bone marrow mesenchymal stem cells,mBM-MSCs)的细胞生物学特性.方法 取6~8周龄ICR小鼠,利用全骨髓反复贴壁和有限稀释培养法分离纯化mBM-MSCs,观察形态特点,测定生长曲线和活力,利用流式细胞仪分析细胞的周期和鉴定表面抗原,诱导其向成骨、软骨及脂肪细胞分化,采用染色法鉴定.结果 新分离的mBM-MSCs多呈小圆形,形态规整.培养传代后,细胞多变为梭形,大小较均匀,形态较一致.随着传代的次数增加,细胞的生长曲线、活力及周期呈现快速发育期、平台期和缓慢期;流式结果细胞CD44、CD73、SCA-1呈阳性反应,部分细胞CD90、CD105、STRO-1呈阳性反应,CD11b和CD45呈阴性反应;诱导分化为成骨细胞后其碱性磷酸酶、茜素红和Von Kossa银染色均呈阳性反应,分化成脂肪细胞后油红O染色呈阳性反应,分化成软骨细胞后阿尔新蓝染色呈阳性反应.结论 ICR小鼠骨髓中分离培养出的MSCs,生物学特点鲜明,适于做进一步研究.

  1. Investigation of specificity ensuring of quality of biological medicinal products on example of drugs Cortexin and Retinalamin

    Directory of Open Access Journals (Sweden)

    N. O. Vetiutneva

    2013-06-01

    Full Text Available Biological medical products nowadays are one of the most promising area at the pharmaceutical market. Biopharmaceutical market has significant benefits such as fast and effective development of production facilities, the development of more effective and safer medical products. The aim of our research was, on the example of medical products Cortexin and Retinalamin, examine the specifics of quality of biological medicinal products in the chain from production to sale. The objects of study - original biological medicines Cortexin and Retinalamin. Comparative, systematic, analytical methods and reviews were used. Biological medical products have fundamental differences from synthetic medicines, due to their source - alive cells which are usually used in their production process. Each production cycle results in a unique finished pharmaceutical products and minimal differences in the modes of production can significantly effect on the properties of biological medical products. Therefore, even if the physical, chemical and biological properties of the product thoroughly studied and described, it does not guarantee therapeutic equivalence of two biological products which are manufactured in different conditions. One of the most important issues today is the problem of maintaining properties and quality of biological medicines. These issues are actively resolving on the native pharmaceutical market: quality control system are developing and implementing in accordance with international standards in order to maintain maximum efficiency of biological medicines and to protect consumers from defective products. Biological products require special conditions of storage and transportation. In order to save physical, chemical and therapeutic properties, strict compliance with the relevant conditions of packaging, transport and intermediate storage, related to deviations in temperature during transportation and storage is needed. The production process

  2. Biological character of human adipose-derived adult stem cells and influence of donor age on cell replication in culture.

    Science.gov (United States)

    Lei, Lei; Liao, WeiMing; Sheng, PuYi; Fu, Ming; He, AiShan; Huang, Gang

    2007-06-01

    To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell's replication activity and the donor's age factor, and to assess the stem cells as a new source for tissue engineering. hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: 61 years old groups). The protein markers (CD29, CD34, CD44, CD45, CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell, and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro. The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula "TD = t x log2/logNt - logN0" was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the 61 years old group (statistical analysis of variance (ANOVA), P=0.002, PhADAS cells replication activity was found in the younger donators, and they represent novel and valuable seed cells for studies of tissue engineering.

  3. Natural Killer Cells: Biology and Clinical Use in Cancer Therapy

    Institute of Scientific and Technical Information of China (English)

    William H. D. Hallett; William J. Murphy

    2004-01-01

    Natural killer (NK) cells have the ability to mediate both bone marrow rejection and promote engraftment, as well as the ability to elicit potent anti-tumor effects. However the clinical results for these processes are still elusive. Greater understanding of NK cell biology, from activating and inhibitory receptor functions to the role of NK cells in allogeneic transplantation, needs to be appreciated in order to draw out the clinical potential of NK cells. Mechanisms of bone marrow cell (BMC) rejection are known to be dependant on inhibitory receptors specific for major histocompatibility complex (MHC) molecules and on activating receptors that have many potential ligands. The modulation of activating and inhibitory receptors may hold the key to clinical success involving NK cells. Pre-clinical studies in mice have shown that different combinations of activating and inhibitory receptors on NK cells can reduce graft-versus-host disease (GVHD), promote engraftment, and provide superior graft-versus-tumor (GVT) responses. Recent clinical data have shown that the use of KIR-ligand incompatibility produces tremendous graft-versus-leukemia effect in patients with acute myeloid leukemia at high risk of relapse. This review will attempt to be a synthesis of current knowledge concerning NK cells, their involvement in BMT, and their use as an immunotherapy for cancer and other hematologic malignancies. Cellular & Molecular Immunology. 2004;1(1):12-21.

  4. Regulation of the cell cycle and centrosome biology by deubiquitylases.

    Science.gov (United States)

    Darling, Sarah; Fielding, Andrew B; Sabat-Pośpiech, Dorota; Prior, Ian A; Coulson, Judy M

    2017-09-12

    Post-translational modification of proteins by ubiquitylation is increasingly recognised as a highly complex code that contributes to the regulation of diverse cellular processes. In humans, a family of almost 100 deubiquitylase enzymes (DUBs) are assigned to six subfamilies and many of these DUBs can remove ubiquitin from proteins to reverse signals. Roles for individual DUBs have been delineated within specific cellular processes, including many that are dysregulated in diseases, particularly cancer. As potentially druggable enzymes, disease-associated DUBs are of increasing interest as pharmaceutical targets. The biology, structure and regulation of DUBs have been extensively reviewed elsewhere, so here we focus specifically on roles of DUBs in regulating cell cycle processes in mammalian cells. Over a quarter of all DUBs, representing four different families, have been shown to play roles either in the unidirectional progression of the cell cycle through specific checkpoints, or in the DNA damage response and repair pathways. We catalogue these roles and discuss specific examples. Centrosomes are the major microtubule nucleating centres within a cell and play a key role in forming the bipolar mitotic spindle required to accurately divide genetic material between daughter cells during cell division. To enable this mitotic role, centrosomes undergo a complex replication cycle that is intimately linked to the cell division cycle. Here, we also catalogue and discuss DUBs that have been linked to centrosome replication or function, including centrosome clustering, a mitotic survival strategy unique to cancer cells with supernumerary centrosomes. © 2017 The Author(s).

  5. Obstructive renal injury: from fluid mechanics to molecular cell biology

    Directory of Open Access Journals (Sweden)

    Alvaro C Ucero

    2010-04-01

    Full Text Available Alvaro C Ucero1,*, Sara Gonçalves2,*, Alberto Benito-Martin1, Beatriz Santamaría1, Adrian M Ramos1, Sergio Berzal1, Marta Ruiz-Ortega1, Jesus Egido1, Alberto Ortiz11Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain; 2Nefrologia e Transplantação Renal, Hospital de Santa Maria EPE, Lisbon, Portugal *Both authors contributed equally to the manuscriptAbstract: Urinary tract obstruction is a frequent cause of renal impairment. The physiopathology of obstructive nephropathy has long been viewed as a mere mechanical problem. However, recent advances in cell and systems biology have disclosed a complex physiopathology involving a high number of molecular mediators of injury that lead to cellular processes of apoptotic cell death, cell injury leading to inflammation and resultant fibrosis. Functional studies in animal models of ureteral obstruction using a variety of techniques that include genetically modified animals have disclosed an important role for the renin-angiotensin system, transforming growth factor-β1 (TGF-β1 and other mediators of inflammation in this process. In addition, high throughput techniques such as proteomics and transcriptomics have identified potential biomarkers that may guide clinical decision-making.Keywords: urinary tract obstruction, renal injury, fluid mechanics, molecular cell biology

  6. Quantum Dots Investigated for Solar Cells

    Science.gov (United States)

    Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Hepp, Aloysius F.

    2001-01-01

    The NASA Glenn Research Center has been investigating the synthesis of quantum dots of CdSe and CuInS2 for use in intermediate-bandgap solar cells. Using quantum dots in a solar cell to create an intermediate band will allow the harvesting of a much larger portion of the available solar spectrum. Theoretical studies predict a potential efficiency of 63.2 percent, which is approximately a factor of 2 better than any state-of-the-art devices available today. This technology is also applicable to thin-film devices--where it offers a potential four-fold increase in power-to-weight ratio over the state of the art. Intermediate-bandgap solar cells require that quantum dots be sandwiched in an intrinsic region between the photovoltaic solar cell's ordinary p- and n-type regions (see the preceding figure). The quantum dots form the intermediate band of discrete states that allow sub-bandgap energies to be absorbed. However, when the current is extracted, it is limited by the bandgap, not the individual photon energies. The energy states of the quantum dot can be controlled by controlling the size of the dot. Ironically, the ground-state energy levels are inversely proportional to the size of the quantum dots. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Ba Wendi et al., in the early 1990's. The most studied quantum dots prepared by this method have been of CdSe. To produce these dots, researchers inject a syringe of the desired organometallic precursors into heated triocytlphosphine oxide (TOPO) that has been vigorously stirred under an inert atmosphere (see the following figure). The solution immediately begins to change from colorless to yellow, then orange and red/brown, as the quantum dots increase in size. When the desired size is reached, the heat is removed from the flask. Quantum dots of different sizes can be identified by placing them under a "black light" and observing the various color differences in

  7. Regenerative Endodontic Procedures: A Perspective from Stem Cell Niche Biology.

    Science.gov (United States)

    Marí-Beffa, Manuel; Segura-Egea, Juan José; Díaz-Cuenca, Aránzazu

    2017-01-01

    Endodontics uses cell therapy strategies to treat pulpal and periapical diseases. During these therapies, surgeons aim to reconstruct the natural microenvironments that regulate the activity of dental stem cells. We searched for more than 400 articles in PubMed using key words from regenerative endodontics and dental stem cell biology. In 268 articles, we reviewed what factors may influence histologic results after preclinical dental treatments that use regenerative endodontic procedures after pulpectomy. Several factors, such as the origin of stem cells, the biomimicry of scaffolds used, and the size of lesions, are considered to influence the histologic appearance of the regenerated pulp-dentin complex after treatments. Information is accumulating on transcription factors that generate the pulp-dentin complex and survival/trophic factors that would benefit niche recovery and histologic results. In this article, we discuss the noninterchangeability of stem cells, the influence of dentin-entrapped molecule release on pulp regeneration and survival of stem cells, and the need of positional markers to assess treatments histologically. The ex vivo amplification of appropriate dental stem cells, the search for scaffolds storing the molecular diversity entrapped in the dentin, and the use of positional transcription factors as histologic markers are necessary to improve future preclinical experiments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Enhancing Scientific Literacy in the Undergraduate Cell Biology Laboratory Classroom

    Directory of Open Access Journals (Sweden)

    Hadiya Woodham

    2016-12-01

    Full Text Available This paper describes the implementation of the Scientific Literacy in Cell Biology (SLCB curriculum in an undergraduate biology laboratory course. The SLCB curriculum incorporated the reading and discussion of primary literature into hands-on and collaborative practical experiences. It was implemented in five stages over an 11-week period, during which students were also introduced to the theory and practice of common cell biology techniques. We report on the effectiveness of the course, as measured by pre- and post-course survey data probing students’ content knowledge and their level of familiarity, confidence, and experience with different skills pertaining to analyzing (reading, interpreting, and discussing primary literature. In the spring 2015 semester, 287 (72% of the 396 students who were enrolled in the laboratory completed both the pre- and post-course survey. The average score on the content questions of the post-course survey was significantly higher (p < 0.0001 than the average score on the pre-course survey. Students reported that they gained greater familiarity, experience, and confidence in the skills that were measured. Our findings may aid in reforming higher-education science laboratory courses to better promote writing, reading, data processing, and presentation skills.

  9. Isolation of biologically active nanomaterial (inclusion bodies from bacterial cells

    Directory of Open Access Journals (Sweden)

    Peternel Špela

    2010-09-01

    Full Text Available Abstract Background In recent years bacterial inclusion bodies (IBs were recognised as highly pure deposits of active proteins inside bacterial cells. Such active nanoparticles are very interesting for further downstream protein isolation, as well as for many other applications in nanomedicine, cosmetic, chemical and pharmaceutical industry. To prepare large quantities of a high quality product, the whole bioprocess has to be optimised. This includes not only the cultivation of the bacterial culture, but also the isolation step itself, which can be of critical importance for the production process. To determine the most appropriate method for the isolation of biologically active nanoparticles, three methods for bacterial cell disruption were analyzed. Results In this study, enzymatic lysis and two mechanical methods, high-pressure homogenization and sonication, were compared. During enzymatic lysis the enzyme lysozyme was found to attach to the surface of IBs, and it could not be removed by simple washing. As this represents an additional impurity in the engineered nanoparticles, we concluded that enzymatic lysis is not the most suitable method for IBs isolation. During sonication proteins are released (lost from the surface of IBs and thus the surface of IBs appears more porous when compared to the other two methods. We also found that the acoustic output power needed to isolate the IBs from bacterial cells actually damages proteins structures, thereby causing a reduction in biological activity. High-pressure homogenization also caused some damage to IBs, however the protein loss from the IBs was negligible. Furthermore, homogenization had no side-effects on protein biological activity. Conclusions The study shows that among the three methods tested, homogenization is the most appropriate method for the isolation of active nanoparticles from bacterial cells.

  10. Human pluripotent stem cells: an emerging model in developmental biology.

    Science.gov (United States)

    Zhu, Zengrong; Huangfu, Danwei

    2013-02-01

    Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

  11. Obstructive renal injury: from fluid mechanics to molecular cell biology

    Science.gov (United States)

    Ucero, Alvaro C; Gonçalves, Sara; Benito-Martin, Alberto; Santamaría, Beatriz; Ramos, Adrian M; Berzal, Sergio; Ruiz-Ortega, Marta; Egido, Jesus; Ortiz, Alberto

    2010-01-01

    Urinary tract obstruction is a frequent cause of renal impairment. The physiopathology of obstructive nephropathy has long been viewed as a mere mechanical problem. However, recent advances in cell and systems biology have disclosed a complex physiopathology involving a high number of molecular mediators of injury that lead to cellular processes of apoptotic cell death, cell injury leading to inflammation and resultant fibrosis. Functional studies in animal models of ureteral obstruction using a variety of techniques that include genetically modified animals have disclosed an important role for the renin-angiotensin system, transforming growth factor-β1 (TGF-β1) and other mediators of inflammation in this process. In addition, high throughput techniques such as proteomics and transcriptomics have identified potential biomarkers that may guide clinical decision-making. PMID:24198613

  12. Obstructive renal injury: from fluid mechanics to molecular cell biology.

    Science.gov (United States)

    Ucero, Alvaro C; Gonçalves, Sara; Benito-Martin, Alberto; Santamaría, Beatriz; Ramos, Adrian M; Berzal, Sergio; Ruiz-Ortega, Marta; Egido, Jesus; Ortiz, Alberto

    2010-04-22

    Urinary tract obstruction is a frequent cause of renal impairment. The physiopathology of obstructive nephropathy has long been viewed as a mere mechanical problem. However, recent advances in cell and systems biology have disclosed a complex physiopathology involving a high number of molecular mediators of injury that lead to cellular processes of apoptotic cell death, cell injury leading to inflammation and resultant fibrosis. Functional studies in animal models of ureteral obstruction using a variety of techniques that include genetically modified animals have disclosed an important role for the renin-angiotensin system, transforming growth factor-β1 (TGF-β1) and other mediators of inflammation in this process. In addition, high throughput techniques such as proteomics and transcriptomics have identified potential biomarkers that may guide clinical decision-making.

  13. Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell.

    Science.gov (United States)

    Cordova, Caio M M; Hoeltgebaum, Daniela L; Machado, Laís D P N; Santos, Larissa Dos

    2016-01-01

    Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas). For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

  14. Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell

    Directory of Open Access Journals (Sweden)

    CAIO M.M. CORDOVA

    2016-01-01

    Full Text Available ABSTRACT Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas. For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

  15. Sec62 bridges the gap from 3q amplification to molecular cell biology in non-small cell lung cancer.

    Science.gov (United States)

    Linxweiler, Maximilian; Linxweiler, Johannes; Barth, Monika; Benedix, Julia; Jung, Volker; Kim, Yoo-Jin; Bohle, Rainer M; Zimmermann, Richard; Greiner, Markus

    2012-02-01

    The molecular carcinogenesis of lung cancer has yet to be clearly elucidated. We investigated the possible oncogenic function of SEC62 in lung cancer, which was predicted based on our previous findings that lung and thyroid cancer tissue samples exhibited increased Sec62 protein levels. The SEC62 gene locus is at 3q26.2, and 3q amplification is reportedly the most common genomic alteration in non-small cell lung cancer. We analyzed SEC62 mRNA and protein levels in tissue samples from lung cancer patients by real-time quantitative PCR, Western blot, and IHC and found significantly increased SEC62 mRNA and protein levels in tumors compared with tumor-free tissue samples from the same patients. Correlation analyses revealed significantly higher Sec62 levels in tumors with lymph node metastases compared with nonmetastatic tumors, as well as in poorly compared with moderately differentiated tumors. On the basis of these promising results, we examined the role of Sec62 in cancer cell biology in vitro. Cell migration assays with lung and thyroid cancer cells showed distinct stimulation of migration in SEC62-overexpressing cells and inhibition of migration in Sec62-depleted cells. Moreover, we found that SEC62 silencing sensitized the cells to thapsigargin-induced endoplasmic reticulum stress. Thus, our results indicate that SEC62 represents a potential candidate oncogene in the amplified 3q region in cases of non-small cell lung cancer and harbors various functions in cancer cell biology.

  16. No question about exciting questions in cell biology.

    Directory of Open Access Journals (Sweden)

    Thomas D Pollard

    2013-12-01

    Full Text Available Although we have a good grasp of many important processes in cell biology, including knowledge of many molecules involved and how they interact with each other, we still do not understand most of the dynamical features that are the essence of living systems. Fortunately, we now have the ability to dissect biological systems in enough detail to understand their dynamics, including the use of mathematical models to account for past observations and predict future experiments. This deep level of mechanistic understanding should be our goal—not simply to satisfy our scientific curiosity, but also to understand the causes of disease well enough to predict risks, make early diagnoses, and treat effectively. Many big questions remain to be answered before we reach this goal of understanding cellular dynamics.

  17. No question about exciting questions in cell biology.

    Science.gov (United States)

    Pollard, Thomas D

    2013-12-01

    Although we have a good grasp of many important processes in cell biology, including knowledge of many molecules involved and how they interact with each other, we still do not understand most of the dynamical features that are the essence of living systems. Fortunately, we now have the ability to dissect biological systems in enough detail to understand their dynamics, including the use of mathematical models to account for past observations and predict future experiments. This deep level of mechanistic understanding should be our goal—not simply to satisfy our scientific curiosity, but also to understand the causes of disease well enough to predict risks, make early diagnoses, and treat effectively. Many big questions remain to be answered before we reach this goal of understanding cellular dynamics.

  18. Multilayer microfluidic systems with indium-tin-oxide microelectrodes for studying biological cells

    Science.gov (United States)

    Wu, Hsiang-Chiu; Lyau, Jia-Bo; Lin, Min-Hsuan; Chuang, Yung-Jen; Chen, Hsin

    2017-07-01

    Contemporary semiconductor and micromachining technologies have been exploited to develop lab-on-a-chip microsystems, which enable parallel and efficient experiments in molecular and cellular biology. In these microlab systems, microfluidics play an important role for automatic transportation or immobilization of cells and bio-molecules, as well as for separation or mixing of different chemical reagents. However, seldom microlab systems allow both morphology and electrophysiology of biological cells to be studied in situ. This kind of study is important, for example, for understanding how neuronal networks grow in response to environmental stimuli. To fulfill this application need, this paper investigates the possibility of fabricating multi-layer photoresists as microfluidic systems directly above a glass substrate with indium-tin-oxide (ITO) electrodes. The microfluidic channels are designed to guide and trap biological cells on top of ITO electrodes, through which the electrical activities of cells can be recorded or elicited. As both the microfluidic system and ITO electrodes are transparent, the cellular morphology is observable easily during electrophysiological studies. Two fabrication processes are proposed and compared. One defines the structure and curing depth of each photoresist layer simply by controlling the exposure time in lithography, while the other further utilizes a sacrificial layer to defines the structure of the bottom layer. The fabricated microfluidic system is proved bio-compatible and able to trap blood cells or neurons. Therefore, the proposed microsystem will be useful for studying cultured cells efficiently in applications such as drug-screening.

  19. SBR-Blood: systems biology repository for hematopoietic cells.

    Science.gov (United States)

    Lichtenberg, Jens; Heuston, Elisabeth F; Mishra, Tejaswini; Keller, Cheryl A; Hardison, Ross C; Bodine, David M

    2016-01-04

    Extensive research into hematopoiesis (the development of blood cells) over several decades has generated large sets of expression and epigenetic profiles in multiple human and mouse blood cell types. However, there is no single location to analyze how gene regulatory processes lead to different mature blood cells. We have developed a new database framework called hematopoietic Systems Biology Repository (SBR-Blood), available online at http://sbrblood.nhgri.nih.gov, which allows user-initiated analyses for cell type correlations or gene-specific behavior during differentiation using publicly available datasets for array- and sequencing-based platforms from mouse hematopoietic cells. SBR-Blood organizes information by both cell identity and by hematopoietic lineage. The validity and usability of SBR-Blood has been established through the reproduction of workflows relevant to expression data, DNA methylation, histone modifications and transcription factor occupancy profiles. Published by Oxford University Press on behalf of Nucleic Acids Research 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  20. Molecular biology of normal melanocytes and melanoma cells.

    Science.gov (United States)

    Bandarchi, Bizhan; Jabbari, Cyrus Aleksandre; Vedadi, Ali; Navab, Roya

    2013-08-01

    Malignant melanoma is one of the most aggressive malignancies in humans and is responsible for 60-80% of deaths from skin cancers. The 5-year survival of patients with metastatic malignant melanoma is about 14%. Its incidence has been increasing in the white population over the past two decades. The mechanisms leading to malignant transformation of melanocytes and melanocytic lesions are poorly understood. In developing malignant melanoma, there is a complex interaction of environmental and endogenous (genetic) factors, including: dysregulation of cell proliferation, programmed cell death (apoptosis) and cell-to-cell interactions. The understanding of genetic alterations in signalling pathways of primary and metastatic malignant melanoma and their interactions may lead to therapeutics modalities, including targeted therapies, particularly in advanced melanomas that have high mortality rates and are often resistant to chemotherapy and radiotherapy. Our knowledge regarding the molecular biology of malignant melanoma has been expanding. Even though several genes involved in melanocyte development may also be associated with melanoma cell development, it is still unclear how a normal melanocyte becomes a melanoma cell. This article reviews the molecular events and recent findings associated with malignant melanoma.

  1. Nanoliter scale microbioreactor array for quantitative cell biology.

    Science.gov (United States)

    Lee, Philip J; Hung, Paul J; Rao, Vivek M; Lee, Luke P

    2006-05-05

    A nanoliter scale microbioreactor array was designed for multiplexed quantitative cell biology. An addressable 8 x 8 array of three nanoliter chambers was demonstrated for observing the serum response of HeLa human cancer cells in 64 parallel cultures. The individual culture unit was designed with a "C" shaped ring that effectively decoupled the central cell growth regions from the outer fluid transport channels. The chamber layout mimics physiological tissue conditions by implementing an outer channel for convective "blood" flow that feeds cells through diffusion into the low shear "interstitial" space. The 2 microm opening at the base of the "C" ring established a differential fluidic resistance up to 3 orders of magnitude greater than the fluid transport channel within a single mold microfluidic device. Three-dimensional (3D) finite element simulation were used to predict fluid transport properties based on chamber dimensions and verified experimentally. The microbioreactor array provided a continuous flow culture environment with a Peclet number (0.02) and shear stress (0.01 Pa) that approximated in vivo tissue conditions without limiting mass transport (10 s nutrient turnover). This microfluidic design overcomes the major problems encountered in multiplexing nanoliter culture environments by enabling uniform cell loading, eliminating shear, and pressure stresses on cultured cells, providing stable control of fluidic addressing, and permitting continuous on-chip optical monitoring.

  2. Review on thin-film transistor technology, its applications, and possible new applications to biological cells

    Science.gov (United States)

    Tixier-Mita, Agnès; Ihida, Satoshi; Ségard, Bertrand-David; Cathcart, Grant A.; Takahashi, Takuya; Fujita, Hiroyuki; Toshiyoshi, Hiroshi

    2016-04-01

    This paper presents a review on state-of-the-art of thin-film transistor (TFT) technology and its wide range of applications, not only in liquid crystal displays (TFT-LCDs), but also in sensing devices. The history of the evolution of the technology is first given. Then the standard applications of TFT-LCDs, and X-ray detectors, followed by state-of-the-art applications in the field of chemical and biochemical sensing are presented. TFT technology allows the fabrication of dense arrays of independent and transparent microelectrodes on large glass substrates. The potential of these devices as electrical substrates for biological cell applications is then described. The possibility of using TFT array substrates as new tools for electrical experiments on biological cells has been investigated for the first time by our group. Dielectrophoresis experiments and impedance measurements on yeast cells are presented here. Their promising results open the door towards new applications of TFT technology.

  3. Effects of transforming growth interacting factor on biological behaviors of gastric carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Liang Hu; Ji-Fang Wen; De-Sheng Xiao; Hui Zhen; Chun-Yan Fu

    2005-01-01

    AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells.METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colonyformation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy.Tumorigenicity of the transfectant cells was also analyzed.RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition.CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.

  4. The cell biology of Tobacco mosaic virus replication and movement

    Directory of Open Access Journals (Sweden)

    Chengke eLiu

    2013-02-01

    Full Text Available Successful systemic infection of a plant by Tobacco mosaic virus (TMV requires three processes that repeat over time: initial establishment and accumulation in invaded cells, intercellular movement and systemic transport. Accumulation and intercellular movement of TMV necessarily involves intracellular transport by complexes containing virus and host proteins and virus RNA during a dynamic process that can be visualized. Multiple membranes appear to assist TMV accumulation, while membranes, microfilaments and microtubules appear to assist TMV movement. Here we review cell biological studies that describe TMV-membrane, -cytoskeleton and -other host protein interactions which influence virus accumulation and movement in leaves and callus tissue. The importance of understanding the developmental phase of the infection in relationship to the observed virus-membrane or -host protein interaction is emphasized. Utilizing the latest observations of TMV-membrane and -host protein interactions within our evolving understanding of the infection ontogeny, a model for TMV accumulation and intracellular spread in a cell biological context is provided.

  5. Relative biological effectiveness in canine osteosarcoma cells irradiated with accelerated charged particles

    Science.gov (United States)

    Maeda, Junko; Cartwright, Ian M.; Haskins, Jeremy S.; Fujii, Yoshihiro; Fujisawa, Hiroshi; Hirakawa, Hirokazu; Uesaka, Mitsuru; Kitamura, Hisashi; Fujimori, Akira; Thamm, Douglas H.; Kato, Takamitsu A.

    2016-01-01

    Heavy ions, characterized by high linear energy transfer (LET) radiation, have advantages compared with low LET protons and photons in their biological effects. The application of heavy ions within veterinary clinics requires additional background information to determine heavy ion efficacy. In the present study, comparison of the cell-killing effects of photons, protons and heavy ions was investigated in canine osteosarcoma (OSA) cells in vitro. A total of four canine OSA cell lines with various radiosensitivities were irradiated with 137Cs gamma-rays, monoenergetic proton beams, 50 keV/µm carbon ion spread out Bragg peak beams and 200 keV/µm iron ion monoenergetic beams. Clonogenic survival was examined using colony-forming as says, and relative biological effectiveness (RBE) values were calculated relative to gamma-rays using the D10 value, which is determined as the dose (Gy) resulting in 10% survival. For proton irradiation, the RBE values for all four cell lines were 1.0–1.1. For all four cell lines, exposure to carbon ions yielded a decreased cell survival compared with gamma-rays, with the RBE values ranging from 1.56–2.10. Iron ions yielded the lowest cell survival among tested radiation types, with RBE values ranging from 3.51–3.69 observed in the three radioresistant cell lines. The radiosensitive cell line investigated demonstrated similar cell survival for carbon and iron ion irradiation. The results of the present study suggest that heavy ions are more effective for killing radioresistant canine OSA cells when compared with gamma-rays and protons. This markedly increased efficiency of cell killing is an attractive reason for utilizing heavy ions for radioresistant canine OSA. PMID:27446477

  6. Mobile Applications in Cell Biology Present New Approaches for Cell Modelling

    Science.gov (United States)

    de Oliveira, Mayara Lustosa; Galembeck, Eduardo

    2016-01-01

    Cell biology apps were surveyed in order to identify whether there are new approaches for modelling cells allowed by the new technologies implemented in tablets and smartphones. A total of 97 apps were identified in 3 stores surveyed (Apple, Google Play and Amazon), they are presented as: education 48.4%, games 26.8% and medicine 15.4%. The apps…

  7. Mobile Applications in Cell Biology Present New Approaches for Cell Modelling

    Science.gov (United States)

    de Oliveira, Mayara Lustosa; Galembeck, Eduardo

    2016-01-01

    Cell biology apps were surveyed in order to identify whether there are new approaches for modelling cells allowed by the new technologies implemented in tablets and smartphones. A total of 97 apps were identified in 3 stores surveyed (Apple, Google Play and Amazon), they are presented as: education 48.4%, games 26.8% and medicine 15.4%. The apps…

  8. Targeted alteration of real and imaginary refractive index of biological cells by histological staining

    OpenAIRE

    Cherkezyan, Lusik; Subramanian, Hariharan; Stoyneva, Valentina; Rogers, Jeremy D.; Yang, Seungmoo; Damania, Dhwanil; Taflove, Allen; Backman, Vadim

    2012-01-01

    Various staining techniques are commonly used in biomedical research to investigate cellular morphology. By inducing absorption of light, staining dyes change the intracellular refractive index due to the Kramers-Kronig relationship. We present a method for creating 2-D maps of real and imaginary refractive indices of stained biological cells using their thickness and absorptance. We validate our technique on dyed polystyrene microspheres and quantify the alteration in refractive index of sta...

  9. iPS-Cinderella Story in Cell Biology

    Directory of Open Access Journals (Sweden)

    Editorial

    2010-01-01

    Full Text Available As we step through the frontiers of modern Science, we are all witnesses to the Cinderella story repeating itself in the form of the iPS. The process of re-programming adult somatic cells to derive Induced Pluripotent stem cells (iPS with the wand of transcription factors and then differentiating them back to adult somatic cells resembles the transformation of Cinderella from a Cinder girl to princess and back to a Cinder girl after the ball; but the iPS-Cinderella is the most fascinating thing ever in cell biology!From the day iPS first made its headlines when it was first produced by Shinya Yamanaka at Kyoto University in Japan, Stem Cell scientists all over the world are re- doing their experiments so far done using other sources like embryonic and adult Stem cells with the iPS cells exploring their potential to the fullest. A Stem Cell science news page without this magic word of iPS is difficult to imagine these days and Scientists have been successful in growing most of the adult Cell types from iPS cells.iPS cells was the key to solve the problems of Immune rejection and Immunosupression required when using other allogeneic Stem cell types which had baffled scientists previously. But the issues raised by scientists about the use of viruses and Oncogenes in producing iPS cells were made groundless when scientists in February 2008 published the discovery of a technique that could remove oncogenes after the induction of pluripotency and now it is possible to induce pluripotency using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. The word of the day is pIPS which are protein-induced Pluripotent stem cells which are iPS cells that were generated without any genetic alteration of the adult cell. This research by the group of Sheng Ding in La Jolla, California made public in April 2009 showed that the generation of poly-arginine anchors was sufficient to induce

  10. Noninvasive Assessment of Cell Fate and Biology in Transplanted Mesenchymal Stem Cells.

    Science.gov (United States)

    Franchi, Federico; Rodriguez-Porcel, Martin

    2017-01-01

    Recently, molecular imaging has become a conditio sine qua non for cell-based regenerative medicine. Developments in molecular imaging techniques, such as reporter gene technology, have increasingly enabled the noninvasive assessment of the fate and biology of cells after cardiovascular applications. In this context, bioluminescence imaging is the most commonly used imaging modality in small animal models of preclinical studies. Here, we present a detailed protocol of a reporter gene imaging approach for monitoring the viability and biology of Mesenchymal Stem Cells transplanted in a mouse model of myocardial ischemia reperfusion injury.

  11. [Better understanding of the biology of cancer cells].

    Science.gov (United States)

    Klein, G

    2000-09-25

    Most forms of cancer arise through a Darwinian evolutionary process. The natural selection that ultimately leads to cancer takes place in somatic tissues although it may be triggered by inherited mutations in a small but significant minority. It favors the growth of clones and subclones that are less and less responsive to normal intra- and extracellular growth control mechanisms. The development of molecular biology has led to the identification of many genes that participate in this somatic evolution. They belong to the following groups: Oncogenes, constitutively activated by structural and/or regulatory changes that drive the cell to continuous proliferation; Tumor suppressor genes, that can inhibit the illegitimately activated cell cycle. They contribute to tumor development by loss mutations or permanent down-regulation, e.g. by methylation; Apoptosis inhibitory genes that can contribute to tumor development by raising the apoptotic threshold, and apoptosis promoting genes that can favor the growth of apoptosis prone tumor cells by their loss or inactivation; DNA repair genes whose inactivation can counteract the normal elimination of cells that carry potentially cancer promoting mutations. Inherited mutations in DNA repair genes can lead to familial cancer syndromes. Immortalizing genes that counteract cellular senescence; Angiogenesis promoting genes whose products may stimulate the vascular supply of tumors; Genes whose structural or functional changes may facilitate the escape of tumor cells from immune rejection; The multi-step development of individual tumors can encompass changes in most or all of these genes. They occur independently of each other and without any fixed order or timing. Tumor emancipation from growth control can therefore proceed along various pathways. It follows that each tumor must be regarded as a biologically unique individual.

  12. The state of the union: the cell biology of fertilization.

    Science.gov (United States)

    Evans, Janice P; Florman, Harvey M

    2002-10-01

    Fertilization is the process by which sperm and egg unite. An expanded understanding of the mechanisms that underlie these events has provided insights into an important aspect of early development and also has proven to be a valuable model in which to study cellular function. In addition, many emerging strategies for contraception and for the treatment of infertility are based on the mechanism of gamete interaction. Here, we discuss the cell and molecular biology of mammalian fertilization, highlight selected recent breakthroughs and attempt to identify key unanswered questions.

  13. Deducing protein function by forensic integrative cell biology.

    Directory of Open Access Journals (Sweden)

    William C Earnshaw

    2013-12-01

    Full Text Available Our ability to sequence genomes has provided us with near-complete lists of the proteins that compose cells, tissues, and organisms, but this is only the beginning of the process to discover the functions of cellular components. In the future, it's going to be crucial to develop computational analyses that can predict the biological functions of uncharacterised proteins. At the same time, we must not forget those fundamental experimental skills needed to confirm the predictions or send the analysts back to the drawing board to devise new ones.

  14. Deducing protein function by forensic integrative cell biology.

    Science.gov (United States)

    Earnshaw, William C

    2013-12-01

    Our ability to sequence genomes has provided us with near-complete lists of the proteins that compose cells, tissues, and organisms, but this is only the beginning of the process to discover the functions of cellular components. In the future, it's going to be crucial to develop computational analyses that can predict the biological functions of uncharacterised proteins. At the same time, we must not forget those fundamental experimental skills needed to confirm the predictions or send the analysts back to the drawing board to devise new ones.

  15. Introduction to Biological Investigations: A First-Year Experience in Experimental Design and Scientific Communication

    Science.gov (United States)

    Foote, Linda C.; Fitzpatrick, Kathleen A.

    2004-01-01

    Introduction to Biological Investigations is a course that was developed to introduce the scientific method through practical application. This active, student-centered experience fosters fundamental skills that promote creativity, critical thinking, and scientific-communication. The course has been well received by first-year students, and…

  16. Cloning Yeast Actin cDNA Leads to an Investigative Approach for the Molecular Biology Laboratory

    Science.gov (United States)

    Black, Michael W.; Tuan, Alice; Jonasson, Erin

    2008-01-01

    The emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the…

  17. Investigation of the Nature of Metaconceptual Processes of Pre-Service Biology Teachers

    Science.gov (United States)

    Yuruk, Nejla; Selvi, Meryem; Yakisan, Mehmet

    2017-01-01

    Purpose of Study: The aim of this study is to investigate the nature of pre-service biology teachers' metaconceptual processes that were active as they participated in metaconceptual teaching activities. Methods: Several instructional activities, including poster drawing, concept mapping, group and class discussions, and journal writing, were…

  18. Cloning Yeast Actin cDNA Leads to an Investigative Approach for the Molecular Biology Laboratory

    Science.gov (United States)

    Black, Michael W.; Tuan, Alice; Jonasson, Erin

    2008-01-01

    The emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the…

  19. Advancing cell biology through proteomics in space and time (PROSPECTS)

    DEFF Research Database (Denmark)

    Lamond, A.I.; Uhlen, M.; Horning, S.

    2012-01-01

    a range of sensitive and quantitative approaches for measuring protein structures and dynamics that promise to revolutionize our understanding of cell biology and molecular mechanisms in both human cells and model organisms. The Proteomics Specification in Time and Space (PROSPECTS) Network is a unique EU......-funded project that brings together leading European research groups, spanning from instrumentation to biomedicine, in a collaborative five year initiative to develop new methods and applications for the functional analysis of cellular proteins. This special issue of Molecular and Cellular Proteomics presents 16...... research papers reporting major recent progress by the PROSPECTS groups, including improvements to the resolution and sensitivity of the Orbitrap family of mass spectrometers, systematic detection of proteins using highly characterized antibody collections, and new methods for absolute as well as relative...

  20. Electroporation of Biological Cells Embedded in a Polycarbonate Filter

    CERN Document Server

    Hercules, W A; Lindesay, J; Schmukler, R; Hercules, William A.; Lindesay, James; Coble, Anna; Schmukler, Robert

    2003-01-01

    The electropermeabilization of biological cell membranes by the application of an external field occurs whenever an applied field exceeds a threshold value. For fields above this threshold value but less than another critical value, the pores formed in the membrane are transient or reversible. Several mechanisms have been proposed for the formation of these transient pores. Here we examine the local electric fields generated for the configuration of cells embedded in a polycarbonate filter, both in the region in and around the pore. We consider the shear forces created in the membrane due to the gradient of the field along the surface of the membrane, and the interaction of the charged molecules in the membrane with this field. A relationship between the electric field strength and the size of the pore formed is derived.

  1. Concise review: current status of stem cells and regenerative medicine in lung biology and diseases.

    Science.gov (United States)

    Weiss, Daniel J

    2014-01-01

    Lung diseases remain a significant and devastating cause of morbidity and mortality worldwide. In contrast to many other major diseases, lung diseases notably chronic obstructive pulmonary diseases (COPDs), including both asthma and emphysema, are increasing in prevalence and COPD is expected to become the third leading cause of disease mortality worldwide by 2020. New therapeutic options are desperately needed. A rapidly growing number of investigations of stem cells and cell therapies in lung biology and diseases as well as in ex vivo lung bioengineering have offered exciting new avenues for advancing knowledge of lung biology as well as providing novel potential therapeutic approaches for lung diseases. These initial observations have led to a growing exploration of endothelial progenitor cells and mesenchymal stem (stromal) cells in clinical trials of pulmonary hypertension and COPD with other clinical investigations planned. Ex vivo bioengineering of the trachea, larynx, diaphragm, and the lung itself with both biosynthetic constructs as well as decellularized tissues have been used to explore engineering both airway and vascular systems of the lung. Lung is thus a ripe organ for a variety of cell therapy and regenerative medicine approaches. Current state-of-the-art progress for each of the above areas will be presented as will discussion of current considerations for cell therapy-based clinical trials in lung diseases.

  2. Natural killer cell biology illuminated by primary immunodeficiency syndromes in humans.

    Science.gov (United States)

    Voss, Matthias; Bryceson, Yenan T

    2017-04-01

    Natural killer (NK) cells are innate immune cytotoxic effector cells well known for their role in antiviral immunity and tumor immunosurveillance. In parts, this knowledge stems from rare inherited immunodeficiency disorders in humans that abrogate NK cell function leading to immune impairments, most notably associated with a high susceptibility to viral infections. Phenotypically, these disorders range from deficiencies selectively affecting NK cells to complex general immune defects that affect NK cells but also other immune cell subsets. Moreover, deficiencies may be associated with reduced NK cell numbers or rather impair specific NK cell effector functions. In recent years, genetic defects underlying the various NK cell deficiencies have been uncovered and have triggered investigative efforts to decipher the molecular mechanisms underlying these disorders. Here we review the associations between inherited human diseases and NK cell development as well as function, with a particular focus on defects in NK cell exocytosis and cytotoxicity. Furthermore we outline how reports of diverse genetic defects have shaped our understanding of NK cell biology. Copyright © 2015. Published by Elsevier Inc.

  3. Effect of survivin siRNA on biological behaviour of breast cancer MCF7 cells

    Institute of Scientific and Technical Information of China (English)

    Hao Wang; Yi-Feng Ye

    2015-01-01

    Objective:To investigate the expression of survivin in breast cancer cell lines and explore the effect of survivin siRNA on biology behavior of breast cancer cells.Methods: Western blot was performed to detect the expression of survivin in breast cancer cell lines. Eukaryotic expression vector pIRES2-EGFP-Survivin siRNA was constructed and transfected in MCF7 cells with liposome, the efficiency of survivin siRNA was measured by Western blot and RT-PCR. Cell proliferation and apoptosis were detected by CCK8 and cell flow respectively. Cell migration and invasion was measured by transwell assay.Results: Survivin was highly expressed in MCF-7. Green fluorescence was found in MCF-7 cells tranfected with survivin siRNA and control siRNA by inverted fluorescence microscopy, the protein and mRNA level of survivin was significantly lower in cells tranfected with survivin siRNA compared with control group. Compared with control group, interfering the expression of survivin by siRNA significantly decreased the proliferation, migration and invasion of MCF-7 cells, the percentage of apoptosis cells was greatly promoted.Conclusions: Interfering the expression of Survivin can inhibit the cell proliferation, migration and invasion, and promot apoptosis in MCF-7.

  4. Structural Investigation of Biological and Semiconductor Nanostructures with Nonlinear Multicontrast Microscopy

    Science.gov (United States)

    Cisek, Richard

    Physical and functional properties of advanced nano-composite materials and biological structures are determined by self-organized atoms and molecules into nanostructures and in turn by microscopic organization of the nanostructures into assemblies of higher structural complexity. Therefore, microscopes are indispensable tools for structural investigations at various levels of organization. In this work, novel nonlinear optical microscopy methods were developed to non-invasively study structural organization at the nanoscopic and microscopic levels. Atomic organization of semiconductor nanowires, molecular organization of amylose biocrystallites in starch granules, and microscopic organization of several photosynthetic organisms was elucidated. The structure of ZnSe nanowires, key components in many modern nanodevices, was investigated using polarization harmonic generation microscopy. Based on nonlinear optical properties of the different crystal lattices, zinc blende and wurtzite nanowires were differentiated, and the three-dimensional orientation of the zinc blende nanowires could be found. The structure of starch granules, a model biocrystal, important in food as well as health sciences, was also investigated using polarization harmonic microscopy. The study was combined with ab initio calculations using the crystal structures of amylose A and B, revealing that second harmonic signals originate from the hydroxide and hydrogen bonds in the starch granules. Visualization of several photosynthetic organisms including the green algae, Chlamydomonas reinhardtii, two species of cyanobacteria, Leptolyngbya sp. and Anabaena sp., aggregates of light-harvesting pigment-protein complexes as well as chloroplasts from green plants were also explored, revealing that future nonlinear microscopy applications could include structural studies of cell walls, the Chlamydomonas eyespot, and photosynthetic membranes. In this study, several nonlinear optical microscopy modalities

  5. Effects of Magnetic Field on Biological Cells and Applications

    Science.gov (United States)

    Chen, Ching-Jen

    2001-03-01

    While there has been extensive research performed in the physics of magnetic fields and the physics and chemistry in life sciences, independent of each other, there has been a paucity of scientific research and development investigating the possible applications of magnetic fields in life sciences. The focus of this presentation is to present the stimulation mechanism by which magnetic fields affect (a) yeast cells (b) plant cells and (c) mammalian normal and cancer cells. Recently we have found that the Saccharomyces Cerevsa yeast growth increases by about 30to a 1 tesla field and the production of CO2 increases by about 30of yeast metabolism may be due to an increase in intercellular interaction and protein channel alignment, the introduction of an alteration in the DNA from the magnetic field exposure or a combination of these mechanisms. We also have found that the application of high magnetic fields (1 tesla and above) can have marked effects on the germination and growth of plants, especially corn, beans and peas. This finding has opened up the possibility of technology developments in botanical growth systems to accelerate seed germination and crop harvesting. Most recently we have investigated the application of high magnetic fields on leukemia, CaCoII and HEP G2 cancer cell lines. We found that when leukemia are exposed to a 12 tesla field for 2 hours has an increase in cell death by about 30that were not exposed to the magnetic field. Viability of CaCoII cells sandwiched between permanent magnets of maximum strength of 1.2 tesla was measured. A decrease in viable cells by 33unexposed cells. HSP 70 was measured for HEPG2 cells that were exposed to permanent magnetic field of 1.2 tesla for 40 minutes and for unexposed cells. It was found that the exposed cells produce 19 times more HSP70 compared to unexposed cells. Our results together with other investigators report suggest a strong evidence of a reduction in the cell growth rate for cancer cells when

  6. Potentials of single-cell biology in identification and validation of disease biomarkers.

    Science.gov (United States)

    Niu, Furong; Wang, Diane C; Lu, Jiapei; Wu, Wei; Wang, Xiangdong

    2016-09-01

    Single-cell biology is considered a new approach to identify and validate disease-specific biomarkers. However, the concern raised by clinicians is how to apply single-cell measurements for clinical practice, translate the message of single-cell systems biology into clinical phenotype or explain alterations of single-cell gene sequencing and function in patient response to therapies. This study is to address the importance and necessity of single-cell gene sequencing in the identification and development of disease-specific biomarkers, the definition and significance of single-cell biology and single-cell systems biology in the understanding of single-cell full picture, the development and establishment of whole-cell models in the validation of targeted biological function and the figure and meaning of single-molecule imaging in single cell to trace intra-single-cell molecule expression, signal, interaction and location. We headline the important role of single-cell biology in the discovery and development of disease-specific biomarkers with a special emphasis on understanding single-cell biological functions, e.g. mechanical phenotypes, single-cell biology, heterogeneity and organization of genome function. We have reason to believe that such multi-dimensional, multi-layer, multi-crossing and stereoscopic single-cell biology definitely benefits the discovery and development of disease-specific biomarkers.

  7. Advancing cell biology through proteomics in space and time (PROSPECTS).

    Science.gov (United States)

    Lamond, Angus I; Uhlen, Mathias; Horning, Stevan; Makarov, Alexander; Robinson, Carol V; Serrano, Luis; Hartl, F Ulrich; Baumeister, Wolfgang; Werenskiold, Anne Katrin; Andersen, Jens S; Vorm, Ole; Linial, Michal; Aebersold, Ruedi; Mann, Matthias

    2012-03-01

    The term "proteomics" encompasses the large-scale detection and analysis of proteins and their post-translational modifications. Driven by major improvements in mass spectrometric instrumentation, methodology, and data analysis, the proteomics field has burgeoned in recent years. It now provides a range of sensitive and quantitative approaches for measuring protein structures and dynamics that promise to revolutionize our understanding of cell biology and molecular mechanisms in both human cells and model organisms. The Proteomics Specification in Time and Space (PROSPECTS) Network is a unique EU-funded project that brings together leading European research groups, spanning from instrumentation to biomedicine, in a collaborative five year initiative to develop new methods and applications for the functional analysis of cellular proteins. This special issue of Molecular and Cellular Proteomics presents 16 research papers reporting major recent progress by the PROSPECTS groups, including improvements to the resolution and sensitivity of the Orbitrap family of mass spectrometers, systematic detection of proteins using highly characterized antibody collections, and new methods for absolute as well as relative quantification of protein levels. Manuscripts in this issue exemplify approaches for performing quantitative measurements of cell proteomes and for studying their dynamic responses to perturbation, both during normal cellular responses and in disease mechanisms. Here we present a perspective on how the proteomics field is moving beyond simply identifying proteins with high sensitivity toward providing a powerful and versatile set of assay systems for characterizing proteome dynamics and thereby creating a new "third generation" proteomics strategy that offers an indispensible tool for cell biology and molecular medicine.

  8. Development and investigation of MOEMS type displacement-pressure sensor for biological information monitoring

    Science.gov (United States)

    Ostasevicius, Vytautas; Malinauskas, Karolis; Janusas, Giedrius; Palevicius, Arvydas; Cekas, Elingas

    2016-04-01

    The aim of this paper is to develop and investigate MOEMS displacement-pressure sensor for biological information monitoring. Developing computational periodical microstructure models using COMSOL Multiphysics modeling software for modal and shape analysis and implementation of these results for design MOEMS displacement-pressure sensor for biological information monitoring was performed. The micro manufacturing technology of periodical microstructure having good diffraction efficiency was proposed. Experimental setup for characterisation of optical properties of periodical microstructure used for design of displacement-pressure sensor was created. Pulsating human artery dynamic characteristics in this paper were analysed.

  9. Lessons learned about spaceflight and cell biology experiments

    Science.gov (United States)

    Hughes-Fulford, Millie

    2004-01-01

    Conducting cell biology experiments in microgravity can be among the most technically challenging events in a biologist's life. Conflicting events of spaceflight include waiting to get manifested, delays in manifest schedules, training astronauts to not shake your cultures and to add reagents slowly, as shaking or quick injection can activate signaling cascades and give you erroneous results. It is important to select good hardware that is reliable. Possible conflicting environments in flight include g-force and vibration of launch, exposure of cells to microgravity for extended periods until hardware is turned on, changes in cabin gases and cosmic radiation. One should have an on-board 1-g control centrifuge in order to eliminate environmental differences. Other obstacles include getting your funding in a timely manner (it is not uncommon for two to three years to pass between notification of grant approval for funding and actually getting funded). That said, it is important to note that microgravity research is worthwhile since all terrestrial life evolved in a gravity field and secrets of biological function may only be answered by removing the constant of gravity. Finally, spaceflight experiments are rewarding and worth your effort and patience.

  10. Lessons learned about spaceflight and cell biology experiments

    Science.gov (United States)

    Hughes-Fulford, Millie

    2004-01-01

    Conducting cell biology experiments in microgravity can be among the most technically challenging events in a biologist's life. Conflicting events of spaceflight include waiting to get manifested, delays in manifest schedules, training astronauts to not shake your cultures and to add reagents slowly, as shaking or quick injection can activate signaling cascades and give you erroneous results. It is important to select good hardware that is reliable. Possible conflicting environments in flight include g-force and vibration of launch, exposure of cells to microgravity for extended periods until hardware is turned on, changes in cabin gases and cosmic radiation. One should have an on-board 1-g control centrifuge in order to eliminate environmental differences. Other obstacles include getting your funding in a timely manner (it is not uncommon for two to three years to pass between notification of grant approval for funding and actually getting funded). That said, it is important to note that microgravity research is worthwhile since all terrestrial life evolved in a gravity field and secrets of biological function may only be answered by removing the constant of gravity. Finally, spaceflight experiments are rewarding and worth your effort and patience.

  11. Machine learning in cell biology - teaching computers to recognize phenotypes.

    Science.gov (United States)

    Sommer, Christoph; Gerlich, Daniel W

    2013-12-15

    Recent advances in microscope automation provide new opportunities for high-throughput cell biology, such as image-based screening. High-complex image analysis tasks often make the implementation of static and predefined processing rules a cumbersome effort. Machine-learning methods, instead, seek to use intrinsic data structure, as well as the expert annotations of biologists to infer models that can be used to solve versatile data analysis tasks. Here, we explain how machine-learning methods work and what needs to be considered for their successful application in cell biology. We outline how microscopy images can be converted into a data representation suitable for machine learning, and then introduce various state-of-the-art machine-learning algorithms, highlighting recent applications in image-based screening. Our Commentary aims to provide the biologist with a guide to the application of machine learning to microscopy assays and we therefore include extensive discussion on how to optimize experimental workflow as well as the data analysis pipeline.

  12. A novel validation algorithm allows for automated cell tracking and the extraction of biologically meaningful parameters.

    Directory of Open Access Journals (Sweden)

    Daniel H Rapoport

    Full Text Available Automated microscopy is currently the only method to non-invasively and label-free observe complex multi-cellular processes, such as cell migration, cell cycle, and cell differentiation. Extracting biological information from a time-series of micrographs requires each cell to be recognized and followed through sequential microscopic snapshots. Although recent attempts to automatize this process resulted in ever improving cell detection rates, manual identification of identical cells is still the most reliable technique. However, its tedious and subjective nature prevented tracking from becoming a standardized tool for the investigation of cell cultures. Here, we present a novel method to accomplish automated cell tracking with a reliability comparable to manual tracking. Previously, automated cell tracking could not rival the reliability of manual tracking because, in contrast to the human way of solving this task, none of the algorithms had an independent quality control mechanism; they missed validation. Thus, instead of trying to improve the cell detection or tracking rates, we proceeded from the idea to automatically inspect the tracking results and accept only those of high trustworthiness, while rejecting all other results. This validation algorithm works independently of the quality of cell detection and tracking through a systematic search for tracking errors. It is based only on very general assumptions about the spatiotemporal contiguity of cell paths. While traditional tracking often aims to yield genealogic information about single cells, the natural outcome of a validated cell tracking algorithm turns out to be a set of complete, but often unconnected cell paths, i.e. records of cells from mitosis to mitosis. This is a consequence of the fact that the validation algorithm takes complete paths as the unit of rejection/acceptance. The resulting set of complete paths can be used to automatically extract important biological parameters

  13. Sub-terahertz resonance spectroscopy of biological macromolecules and cells

    Science.gov (United States)

    Globus, Tatiana; Moyer, Aaron; Gelmont, Boris; Khromova, Tatyana; Sizov, Igor; Ferrance, Jerome

    2013-05-01

    Recently we introduced a Sub-THz spectroscopic system for characterizing vibrational resonance features from biological materials. This new, continuous-wave, frequency-domain spectroscopic sensor operates at room temperature between 315 and 480 GHz with spectral resolution of at least 1 GHz and utilizes the source and detector components from Virginia Diode, Inc. In this work we present experimental results and interpretation of spectroscopic signatures from bacterial cells and their biological macromolecule structural components. Transmission and absorption spectra of the bacterial protein thioredoxin, DNA and lyophilized cells of Escherichia coli (E. coli), as well as spores of Bacillus subtillis and B. atrophaeus have been characterized. Experimental results for biomolecules are compared with absorption spectra calculated using molecular dynamics simulation, and confirm the underlying physics for resonance spectroscopy based on interactions between THz radiation and vibrational modes or groups of modes of atomic motions. Such interactions result in multiple intense and narrow specific resonances in transmission/absorption spectra from nano-gram samples with spectral line widths as small as 3 GHz. The results of this study indicate diverse relaxation dynamic mechanisms relevant to sub-THz vibrational spectroscopy, including long-lasting processes. We demonstrate that high sensitivity in resolved specific absorption fingerprints provides conditions for reliable detection, identification and discrimination capability, to the level of strains of the same bacteria, and for monitoring interactions between biomaterials and reagents in near real-time. Additionally, it creates the basis for the development of new types of advanced biological sensors through integrating the developed system with a microfluidic platform for biomaterial samples.

  14. Inhibition of survivin influences the biological activities of canine histiocytic sarcoma cell lines.

    Directory of Open Access Journals (Sweden)

    Hiroki Yamazaki

    Full Text Available Canine histiocytic sarcoma (CHS is an aggressive malignant neoplasm that originates from histiocytic lineage cells, including dendritic cells and macrophages, and is characterized by progressive local infiltration and a very high metastatic potential. Survivin is as an apoptotic inhibitory factor that has major functions in cell proliferation, including inhibition of apoptosis and regulation of cell division, and is expressed in most types of human and canine malignant neoplasms, including melanoma and osteosarcoma. To investigate whether survivin was expressed at high levels in CHS and whether its expression was correlated with the aggressive biological behavior of CHS, we assessed relation between survivin expression and CHS progression, as well as the effects of survivin inhibition on the biological activities of CHS cells. We comparatively analyzed the expression of 6 selected anti-apoptotic genes, including survivin, in specimens from 30 dogs with histiocytic sarcoma and performed annexin V staining to evaluate apoptosis, methylthiazole tetrazolium assays to assess cell viability and chemosensitivity, and latex bead assays to measure changes in phagocytic activities in 4 CHS cell lines and normal canine fibroblasts transfected with survivin siRNA. Survivin gene expression levels in 30 specimens were significantly higher than those of the other 6 genes. After transfection with survivin siRNA, apoptosis, cell growth inhibition, enhanced chemosensitivity, and weakened phagocytic activities were observed in all CHS cell lines. In contrast, normal canine fibroblasts were not significantly affected by survivin knockdown. These results suggested that survivin expression may mediate the aggressive biological activities of CHS and that survivin may be an effective therapeutic target for the treatment of CHS.

  15. How chemistry supports cell biology: the chemical toolbox at your service.

    Science.gov (United States)

    Wijdeven, Ruud H; Neefjes, Jacques; Ovaa, Huib

    2014-12-01

    Chemical biology is a young and rapidly developing scientific field. In this field, chemistry is inspired by biology to create various tools to monitor and modulate biochemical and cell biological processes. Chemical contributions such as small-molecule inhibitors and activity-based probes (ABPs) can provide new and unique insights into previously unexplored cellular processes. This review provides an overview of recent breakthroughs in chemical biology that are likely to have a significant impact on cell biology. We also discuss the application of several chemical tools in cell biology research.

  16. Synthetic biology outside the cell: linking computational tools to cell-free systems.

    Science.gov (United States)

    Lewis, Daniel D; Villarreal, Fernando D; Wu, Fan; Tan, Cheemeng

    2014-01-01

    As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems.

  17. Cell biology and biotechnology research for exploration of the Moon and Mars

    Science.gov (United States)

    Pellis, N.; North, R.

    Health risks generated by human long exposure to radiation, microgravity, and unknown factors in the planetary environment are the major unresolved issues for human space exploration. A complete characterization of human and other biological systems adaptation processes to long-duration space missions is necessary for the development of countermeasures. The utilization of cell and engineered tissue cultures in space research and exploration complements research in human, animal, and plant subjects. We can bring a small number of humans, animals, or plants to the ISS, Moon, and Mars. However, we can investigate millions of their cells during these missions. Furthermore, many experiments can not be performed on humans, e.g. radiation exposure, cardiac muscle. Cells from critical tissues and tissue constructs per se are excellent subjects for experiments that address underlying mechanisms important to countermeasures. The development of cell tissue engineered for replacement, implantation of biomaterial to induce tissue regeneration (e.g. absorbable collagen matrix for guiding tissue regeneration in periodontal surgery), and immunoisolation (e.g. biopolymer coating on transplanted tissues to ward off immunological rejection) are good examples of cell research and biotechnology applications. NASA Cell Biology and Biotechnology research include Bone/Muscle and Cardiovascular cell culture and tissue engineering; Environmental Health and Life Support Systems; Immune System; Radiation; Gravity Thresholds ; and Advanced Biotechnology Development to increase the understanding of animal and plant cell adaptive behavior when exposed to space, and to advance technologies that facilitates exploration. Cell systems can be used to investigate processes related to food, microbial proliferation, waste management, biofilms and biomaterials. The NASA Cell Science Program has the advantage of conducting research in microgravity based on significantly small resources, and the ability to

  18. Computational Biology Methods for Characterization of Pluripotent Cells.

    Science.gov (United States)

    Araúzo-Bravo, Marcos J

    2016-01-01

    Pluripotent cells are a powerful tool for regenerative medicine and drug discovery. Several techniques have been developed to induce pluripotency, or to extract pluripotent cells from different tissues and biological fluids. However, the characterization of pluripotency requires tedious, expensive, time-consuming, and not always reliable wet-lab experiments; thus, an easy, standard quality-control protocol of pluripotency assessment remains to be established. Here to help comes the use of high-throughput techniques, and in particular, the employment of gene expression microarrays, which has become a complementary technique for cellular characterization. Research has shown that the transcriptomics comparison with an Embryonic Stem Cell (ESC) of reference is a good approach to assess the pluripotency. Under the premise that the best protocol is a computer software source code, here I propose and explain line by line a software protocol coded in R-Bioconductor for pluripotency assessment based on the comparison of transcriptomics data of pluripotent cells with an ESC of reference. I provide advice for experimental design, warning about possible pitfalls, and guides for results interpretation.

  19. Time constant determination for electrical equivalent of biological cells

    Science.gov (United States)

    Dubey, Ashutosh Kumar; Dutta-Gupta, Shourya; Kumar, Ravi; Tewari, Abhishek; Basu, Bikramjit

    2009-04-01

    The electric field interactions with biological cells are of significant interest in various biophysical and biomedical applications. In order to study such important aspect, it is necessary to evaluate the time constant in order to estimate the response time of living cells in the electric field (E-field). In the present study, the time constant is evaluated by considering the hypothesis of electrical analog of spherical shaped cells and assuming realistic values for capacitance and resistivity properties of cell/nuclear membrane, cytoplasm, and nucleus. In addition, the resistance of cytoplasm and nucleoplasm was computed based on simple geometrical considerations. Importantly, the analysis on the basis of first principles shows that the average values of time constant would be around 2-3 μs, assuming the theoretical capacitance values and the analytically computed resistance values. The implication of our analytical solution has been discussed in reference to the cellular adaptation processes such as atrophy/hypertrophy as well as the variation in electrical transport properties of cellular membrane/cytoplasm/nuclear membrane/nucleoplasm.

  20. Molecular biology of breast cancer stem cells: potential clinical applications.

    Science.gov (United States)

    Nguyen, Nam P; Almeida, Fabio S; Chi, Alex; Nguyen, Ly M; Cohen, Deirdre; Karlsson, Ulf; Vinh-Hung, Vincent

    2010-10-01

    Breast cancer stem cells (CSC) have been postulated recently as responsible for failure of breast cancer treatment. The purpose of this study is to review breast CSCs molecular biology with respect to their mechanism of resistance to conventional therapy, and to develop treatment strategies that may improve survival of breast cancer patients. A literature search has identified in vitro and in vivo studies of breast CSCs. Breast CSCs overexpress breast cancer resistance protein (BCRP) which allows cancer cells to transport actively chemotherapy agents out of the cells. Radioresistance is modulated through activation of Wnt signaling pathway and overexpression of genes coding for glutathione. Lapatinib can selectively target HER-2 positive breast CSCs and improves disease-free survival in these patients. Metformin may target basal type breast CSCs. Parthenolide and oncolytic viruses are promising targeting agents for breast CSCs. Future clinical trials for breast cancer should include anti-cancer stem cells targeting agents in addition to conventional chemotherapy. Hypofractionation radiotherapy may be indicated for residual disease post chemotherapy.

  1. Engineering molecular circuits using synthetic biology in mammalian cells.

    Science.gov (United States)

    Wieland, Markus; Fussenegger, Martin

    2012-01-01

    Synthetic biology has made significant leaps over the past decade, and it now enables rational and predictable reprogramming of cells to conduct complex physiological activities. The bases for cellular reprogramming are mainly genetic control components affecting gene expression. A huge variety of these modules, ranging from engineered fusion proteins regulating transcription to artificial RNA devices affecting translation, is available, and they often feature a highly modular scaffold. First endeavors to combine these modules have led to autoregulated expression systems and genetic cascades. Analogous to the rational engineering of electronic circuits, the existing repertoire of artificial regulatory elements has further enabled the ambitious reprogramming of cells to perform Boolean calculations or to mimic the oscillation of circadian clocks. Cells harboring synthetic gene circuits are not limited to cell culture, as they have been successfully implanted in animals to obtain tailor-made therapeutics that have made it possible to restore urea or glucose homeostasis as well as to offer an innovative approach to artificial insemination.

  2. Use of colloidal gold cytochemistry in the study of the basic cell biology of cancer.

    Science.gov (United States)

    Willingham, M C

    1989-01-01

    We are currently investigating the morphologic aspects of two areas of the basic cell biology of cancer: tumor-specific surface antigens as targets for immunotoxins, and the phenomenon of multidrug resistance in chemotherapy of human tumors. Colloidal gold cytochemistry has provided a useful method for the electron-microscopic cytochemical detection of materials endocytosed by cells in culture. This technique has been used to study the internalization pathway of ligands bound to the surface of cancer cells, particularly antibodies for use as immunologic targeting reagents for the construction of immunotoxins. These colloidal gold conjugates with monoclonal antibodies have demonstrated the internalization of these immunologic reagents through coated pits and receptosomes, which is a necessary step in the delivery of immunotoxins into the cell where they can mediate their cell-killing functions. Morphologic methods have been employed for the screening and selection of monoclonal antibodies reactive with the surface of human ovarian cancer cells for use as immunotoxins and have demonstrated the in vivo activity of immunotoxins made with these antibodies and Pseudomonas exotoxin in a nude mouse model system. In other studies, we have employed such reagents for the immunocytochemical detection of the surface expression of P170, the cell-surface efflux pump protein responsible for the phenotype of multidrug resistance in tumor cells, and to investigate the distribution of this protein by using immunocytochemistry in normal human tissues. These results have suggested a role for P170 in normal cell membrane transport of metabolites in various organ systems.

  3. The use of buccal cells in human biological monitoring

    Directory of Open Access Journals (Sweden)

    Ewa Błaszczyk

    2012-12-01

    Full Text Available One of the basic methods for determining the degree of environmental risk posed to humans is identification of harmful substances in various environmental elements (air, water, soil, food. In contrast to environmental monitoring human biological monitoring (HBM enables the estimation of an absorbed dose, general or localized in a specific organ. HBM enables the assessment of exposure to substances which are absorbed by the body via different exposure pathways and with different contaminant carriers. It is based on the measurement of indicators, the so-called biomarkers, in body fluids (blood, urine, saliva, etc. or in tissues and organs. Biomarkers can be divided into markers of exposure, effects and susceptibility. A particularly useful method is determination of adducts, i.e. carcinogenic compounds (or their metabolites with proteins or DNA, which are markers of exposure. Biomarkers of biological effects are different cytogenetic changes, including micronuclei. These are extranuclear structures containing fragments of chromatin (arising as a result of DNA breaks or whole chromosomes (damage to the spindle apparatus during mitosis. Up to now most studies on the DNA adduct levels and micronuclei have been conducted in peripheral lymphocytes. At present, studies using blood, especially in children to restricted to ethical aspects, and therefore tests using epithelial cells from the oral cavity have become more popular. Epithelial cells are the main building material of an epithelial tissue which makes up about 60% of all cells of the human body. The main function of the epithelial tissue is covering and lining of the outer and inner surfaces of the body. Epithelium underwent high specialisation in various parts of the human body, which is associated with its structure and function. Human oral cavity is covered by stratified squamous epithelium, which is comprised of cells called keratinocytes. Oral epithelial cells may differentiate in two

  4. In vivo cell biology of cancer cells visualized with fluorescent proteins.

    Science.gov (United States)

    Hoffman, Robert M

    2005-01-01

    This chapter describes a new cell biology where the behavior of individual cells can be visualized in the living animal. Previously it has been demonstrated that fluorescent proteins can be used for whole-body imaging of metastatic tumor growth, bacterial infection, and gene expression. An example of the new cell biology is dual-color fluorescence imaging using red fluorescent protein (RFP)-expressing tumors transplanted in green fluorescent protein (GFP)-expressing transgenic mice. These models show with great clarity the details of tumor-stroma interactions and especially tumor-induced angiogenesis, tumor-infiltrating lymphocytes, stromal fibroblasts, and macrophages. Another example is the color coding of cells with RFP or GFP such that both cell types can be simultaneously visualized in vivo. Stem cells can also be visualized and tracked in vivo. Mice in which the regulatory elements of the stem cell marker nestin drive GFP expression enable nascent vasculature to be visualized interacting with transplanted RFP-expressing cancer cells. Nestin-driven GFP expression can also be used to visualize hair follicle stem cells. Dual-color cells expressing GFP in the nucleus and RFP in the cytoplasm enable real-time visualization of nuclear-cytoplasm dynamics including cell cycle events and apoptosis. Highly elongated cancer cells in capillaries in living mice were observed within skin flaps. The migration velocities of the cancer cells in the capillaries were measured by capturing images of the dual-color fluorescent cells over time. The cells in the capillaries elongated to fit the width of these vessels. The use of the dual-color cancer cells differentially labeled in the cytoplasm and nucleus and associated fluorescent imaging provide a powerful tool to understand the mechanism of cancer cell migration and deformation in small vessels.

  5. Cells from icons to symbols: molecularizing cell biology in the 1980s.

    Science.gov (United States)

    Serpente, Norberto

    2011-12-01

    Over centuries cells have been the target of optical and electronic microscopes as well as others technologies, with distinctive types of visual output. Whilst optical technologies produce images 'evident to the eye', the electronic and especially the molecular create images that are more elusive to conceptualization and assessment. My study applies the semiotic approach to the production of images in cell biology to capture the shift from microscopic images to non-traditional visual technologies around 1980. Here I argue that the visual shift that coincides with the growing dominance of molecular biology involves a change from iconic to symbolic forms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Cell reprogramming: a new chemical approach to stem cell biology and tissue regeneration.

    Science.gov (United States)

    Anastasia, L; Piccoli, M; Garatti, A; Conforti, E; Scaringi, R; Bergante, S; Castelvecchio, S; Venerando, B; Menicanti, L; Tettamanti, G

    2011-02-01

    Generation of pluripotent stem cells (iPSCs) from adult fibroblasts starts a "new era" in stem cell biology, as it overcomes several key issues associated with previous approaches, including the ethical concerns associated with human embryonic stem cells. However, as the genetic approach for cell reprogramming has already shown potential safety issues, a chemical approach may be a safer and easier alternative. Moreover, a chemical approach could be advantageous not only for the de-differentiation phase, but also for inducing reprogrammed cells into the desired cell type with higher efficiency than current methodologies. Finally, a chemical approach may be envisioned to activate resident adult stem cells to proliferate and regenerate damaged tissues in situ, without the need for exogenous cell injections.

  7. The effect of cosmic rays on biological systems - an investigation during GLE events

    Science.gov (United States)

    Belisheva, N. K.; Lammer, H.; Biernat, H. K.; Vashenuyk, E. V.

    2012-01-01

    In this study, first direct and circumstantial evidences of the effects of cosmic rays (CR) on biological systems are presented. A direct evidence of biological effects of CR is demonstrated in experiments with three cellular lines growing in culture during three events of Ground Level Enhancement (GLEs) in the neutron count rate detected by ground-based neutron monitor in October 1989. Various phenomena associated with DNA lesion on the cellular level demonstrate coherent dynamics of radiation effects in all cellular lines coincident with the time of arrival of high-energy solar particles to the near-Earth space and with the main peak in GLE. These results were obtained in the course of six separate experiments, with partial overlapping of the time of previous and subsequent experiments, which started and finished in the quiet period of solar activity (SA). A significant difference between the values of multinuclear cells in all cellular lines in the quiet period and during GLE events indicates that the cause of radiation effects in the cell cultures is an exposure of cells to the secondary solar CR near the Earth's surface. The circumstantial evidence was obtained by statistical analysis of cases of congenital malformations (CM) at two sites in the Murmansk region. The number of cases of all classes of CM reveals a significant correlation with the number of GLE events. The number of cases of CM with pronounced chromosomal abnormalities clearly correlates with the GLE events that occurred a year before the birth of a child. We have found a significant correlation between modulations of the water properties and daily background variations of CR intensity. We believe that the effects of CR on biological systems can be also mediated by fluctuations in water properties, considered as one of possible mechanisms controlling the effects of CRs on biological systems.

  8. Stem cell biology in thyroid cancer: Insights for novel therapies

    Science.gov (United States)

    Bhatia, Parisha; Tsumagari, Koji; Abd Elmageed, Zakaria Y; Friedlander, Paul; Buell, Joseph F; Kandil, Emad

    2014-01-01

    Currently, thyroid cancer is one of the most common endocrine cancer in the United States. A recent involvement of sub-population of stem cells, cancer stem cells, has been proposed in different histological types of thyroid cancer. Because of their ability of self-renewal and differentiation into various specialized cells in the body, these putative cells drive tumor genesis, metastatic activity and are responsible to provide chemo- and radioresistant nature to the cancer cells in the thyroid gland. Our Review was conducted from previously published literature to provide latest apprises to investigate the role of embryonic, somatic and cancer stem cells, and discusses the hypothesis of epithelial-mesenchymal transition. Different methods for their identification and isolation through stemness markers using various in vivo and in vitro methods such as flow cytometry, thyrosphere formation assay, aldehyde dehydrogenase activity and ATP-binding cassette sub-family G member 2 efflux-pump mediated Hoechst 33342 dye exclusion have been discussed. The review also outlines various setbacks that still remain to target these tumor initiating cells. Future perspectives of therapeutic strategies and their potential to treat advanced stages of thyroid cancer are also disclosed in this review. PMID:25426258

  9. Stem cell biology in thyroid cancer: Insights for novel therapies

    Institute of Scientific and Technical Information of China (English)

    Parisha; Bhatia; Koji; Tsumagari; Zakaria; Y; Abd; Elmageed; Paul; Friedlander; Joseph; F; Buell; Emad; Kandil

    2014-01-01

    Currently, thyroid cancer is one of the most common endocrine cancer in the United States. A recent involvement of sub-population of stem cells, cancer stem cells, has been proposed in different histological types of thyroid cancer. Because of their ability of self-renewal and differentiation into various specialized cells in the body, these putative cells drive tumor genesis, metastatic activity and are responsible to provide chemo- and radioresistant nature to the cancer cells in the thyroid gland. Our Review was conducted from previously published literature to provide latest apprises to investigate the role of embryonic, somatic and cancer stem cells, and discusses the hypothesis of epithelial-mesenchymal transition. Different methods for their identification and isolation through stemness markers using various in vivo and in vitro methods such as flow cytometry, thyrosphere formation assay, aldehyde dehydrogenase activity and ATP-binding cassette sub-family G member 2 efflux-pump mediated Hoechst 33342 dye exclusion have been discussed. The review also outlines various setbacks that still remain to target these tumor initiating cells. Future perspectives of therapeutic strategies and their potential to treat advanced stages of thyroid cancer are also disclosed in this review.

  10. Mitochondrial uptake of thiamin pyrophosphate: physiological and cell biological aspects.

    Directory of Open Access Journals (Sweden)

    Veedamali S Subramanian

    Full Text Available Mammalian cells obtain vitamin B1 (thiamin from their surrounding environment and convert it to thiamin pyrophosphate (TPP in the cytoplasm. Most of TPP is then transported into the mitochondria via a carrier-mediated process that involves the mitochondrial thiamin pyrophosphate transporter (MTPPT. Knowledge about the physiological parameters of the MTPP-mediated uptake process, MTPPT targeting and the impact of clinical mutations in MTPPT in patients with Amish lethal microcephaly and neuropathy and bilateral striatal necrosis are not fully elucidated, and thus, were addressed in this study using custom-made (3H-TPP as a substrate and mitochondria isolated from mouse liver and human-derived liver HepG2 cells. Results showed (3H-TPP uptake by mouse liver mitochondria to be pH-independent, saturable (Km = 6.79±0.53 µM, and specific for TPP. MTPPT protein was expressed in mouse liver and HepG2 cells, and confocal images showed a human (hMTPPT-GFP construct to be targeted to mitochondria of HepG2 cells. A serial truncation analysis revealed that all three modules of hMTPPT protein cooperated (although at different levels of efficiency in mitochondrial targeting rather than acting autonomously as independent targeting module. Finally, the hMTPPT clinical mutants (G125S and G177A showed proper mitochondrial targeting but displayed significant inhibition in (3H-TPP uptake and a decrease in level of expression of the MTPPT protein. These findings advance our knowledge of the physiology and cell biology of the mitochondrial TPP uptake process. The results also show that clinical mutations in the hMTPPT system impair its functionality via affecting its level of expression with no effect on its targeting to mitochondria.

  11. A Human Corneal Epithelial Cell Line Model for Limbal Stem Cell Biology and Limbal Immunobiology.

    Science.gov (United States)

    Shaharuddin, Bakiah; Ahmad, Sajjad; Md Latar, Nani; Ali, Simi; Meeson, Annette

    2016-10-14

    : Limbal stem cell (LSC) deficiency is a visually debilitating condition caused by abnormal maintenance of LSCs. It is treated by transplantation of donor-derived limbal epithelial cells (LECs), the success of which depends on the presence and quality of LSCs within the transplant. Understanding the immunobiological responses of these cells within the transplants could improve cell engraftment and survival. However, human corneal rings used as a source of LSCs are not always readily available for research purposes. As an alternative, we hypothesized that a human telomerase-immortalized corneal epithelial cell (HTCEC) line could be used as a model for studying LSC immunobiology. HTCEC constitutively expressed human leukocyte antigen (HLA) class I but not class II molecules. However, when stimulated by interferon-γ, HTCECs then expressed HLA class II antigens. Some HTCECs were also migratory in response to CXCL12 and expressed stem cell markers, Nanog, Oct4, and Sox2. In addition because both HTCECs and LECs contain side population (SP) cells, which are an enriched LSC population, we used these SP cells to show that some HTCEC SP cells coexpressed ABCG2 and ABCB5. HTCEC SP and non-side population (NSP) cells also expressed CXCR4, but the SP cells expressed higher levels. Both were capable of colony formation, but the NSP colonies were smaller and contained fewer cells. In addition, HTCECs expressed ΔNp63α. These results suggest the HTCEC line is a useful model for further understanding LSC biology by using an in vitro approach without reliance on a supply of human tissue. Limbal stem cell deficiency is a painful eye condition caused by abnormal maintenance of limbal stem cells. It is treated by transplantation of limbal epithelial cells derived from human tissue. The success of this treatment depends of the quality of the cells transplanted; however, some transplants fail. Understanding more about the immunobiology of these cells within the transplants could

  12. Competency development in antibody production in cancer cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.S.

    1998-12-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The main objective of this project was to develop a rapid recombinant antibody production technology. To achieve the objective, the authors employed (1) production of recombinant antigens that are important for cell cycle regulation and DNA repair, (2) immunization and specific selection of antibody-producing lymphocytes using the flow cytometry and magnetic bead capturing procedure, (3) construction of single chain antibody library, (4) development of recombinant vectors that target, express, and regulate the expression of intracellular antibodies, and (5) specific inhibition of tumor cell growth in tissue culture. The authors have accomplished (1) optimization of a selection procedure to isolate antigen-specific lymphocytes, (2) optimization of the construction of a single-chain antibody library, and (3) development of a new antibody expression vector for intracellular immunization. The future direction of this research is to continue to test the potential use of the intracellular immunization procedure as a tool to study functions of biological molecules and as an immuno-cancer therapy procedure to inhibit the growth of cancer cells.

  13. [Adhesive cell interactions in the biology of cancer].

    Science.gov (United States)

    Bocharova, O A

    2002-01-01

    The present review describes a hypothesis for a critical role of cell adhesive interactions in tumorigenesis. Dysregulation of tissue cell-cell interactions initiates first of all local (in the tissue) and then general (in whole body) conditions for tumor growth. Otherwise imbalance of tissue-specific adhesion factor at the very beginning of carcinogenesis is considered to trigger a cascade of pathological reactions responsible for more severe adhesive disorders that are in turn critical for the "totalitarian" behavior of a tumor and its "colonization" of other tissues and organs. Impaired disturbance is likely to be the key mechanism of carcinogenesis since it is significantly associated with the main features of a tumor: tissue proliferation control loss, anaplasia, invasion, metastasis, and immune surveillance deficit. The hypothesis is supported by evolutionary, biological, histological, immunological, and clinical arguments whose combination does not characterize any other known mechanisms of oncogenesis. The concept of adhesiveness opens new possibilities for the diagnosis, prevention, and treatment of tumors and also improves a strategy for designing new drugs.

  14. Chemical modification allows phallotoxins and amatoxins to be used as tools in cell biology

    Directory of Open Access Journals (Sweden)

    Jan Anderl

    2012-11-01

    Full Text Available Phallotoxins inhibit the dynamics of microfilaments in cells and lead to apoptosis. Due to poor cellular uptake these effects cannot be studied in live cells, even at millimolar toxin concentrations, nor can phalloidin be used for the elimination of tumor cells. Uptake is greatly enhanced by conjugation of phallotoxins to either lipophilic or polycationic moieties, such as oleic acid, polylysine, or Tat-peptide. These conjugates were lethally toxic for cells, e.g., mouse fibroblasts or Jurkat leukemia cells, in the micromolar range. Uptake into cells starts with the attachment of the toxin conjugates to the plasma membrane, followed by endocytosis and, in most cases, cleavage of the toxin from the carrier. Interestingly, the internalization rate of phalloidin into cells was also significantly increased by the fluorescent moiety tetramethylrhodaminyl, as well as by high molecular weight methoxy-polyethyleneglycol, two compounds unknown so far for their uptake-mediating activity. Conjugation to carriers as investigated in this work will allow the use of phallotoxins in experimental cell biology and possibly in tumor therapy. The findings obtained with phallotoxins could be applied also to the family of amatoxins, where α-amanitin, for example, when conjugated to oleic acid was more than 100-fold more toxic for cells than the native toxin. This suggests the possibility of a more general use of the moieties examined here to enhance the uptake of hydrophilic peptides, or drugs, into live cells.

  15. Phenotypic evolutionary models in stem cell biology: replacement, quiescence, and variability.

    Directory of Open Access Journals (Sweden)

    Marc Mangel

    Full Text Available Phenotypic evolutionary models have been used with great success in many areas of biology, but thus far have not been applied to the study of stem cells except for investigations of cancer. We develop a framework that allows such modeling techniques to be applied to stem cells more generally. The fundamental modeling structure is the stochastic kinetics of stem cells in their niche and of transit amplifying and fully differentiated cells elsewhere in the organism, with positive and negative feedback. This formulation allows graded signals to be turned into all or nothing responses, and shows the importance of looking beyond the niche for understanding how stem cells behave. Using the deterministic version of this framework, we show how competition between different stem cell lines can be analyzed, and under what circumstances stem cells in a niche will be replaced by other stem cells with different phenotypic characteristics. Using the stochastic version of our framework and state dependent life history theory, we show that the optimal behavior of a focal stem cell will involve long periods of quiescence and that a population of identical stem cells will show great variability in the times at which activity occurs; we compare our results with classic ones on quiescence and variability in the hematopoietic system.

  16. cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology

    Science.gov (United States)

    Johnson, Graham T.; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.

    2014-01-01

    cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of models and with recipes and models for five biological systems: blood plasma, cytoplasm, synaptic vesicles, HIV and a mycoplasma cell. We have applied cellPACK to model distributions of HIV envelope protein to test several hypotheses for consistency with experimental observations. Biologists, educators, and outreach specialists can interact with cellPACK models, develop new recipes and perform packing experiments through scripting and graphical user interfaces at http://cellPACK.org. PMID:25437435

  17. The 2~(nd) Guangzhou International Forum on the Frontier of Stem Cell and Regeneration Biology Invitations

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ The forum will focus on the following topics: reprogramming of stem cell, chemical biology researchin stem cell, applied research in embryonic and somatic stem cells, stem cell and drug R&D, developmentand mode animal research, stem cell biology and cloning. The Forum will invite members of the CASOverseas Innovation Team on stem cells and cloning, expert panel members of the national key projecton Development and Procreation, the nation's 973 Project chief scientists and other professionals of thearea from all over the world.

  18. The Ferrier Lecture 1998: The molecular biology of consciousness investigated with genetically modified mice

    OpenAIRE

    Changeux, Jean-Pierre

    2006-01-01

    The question is raised of the relevance of experimental work with the mouse and some of its genetically modified individuals in the study of consciousness. Even if this species does not go far beyond the level of ‘minimal consciousness’, it may be a useful animal model to examine the elementary building blocks of consciousness using the methods of molecular biology jointly with investigations at the physiological and behavioural levels. These building blocks which are anticipated to be univer...

  19. Validation of Procedures for Monitoring Crewmember Immune Function - Short Duration Biological Investigation

    Science.gov (United States)

    Sams, Clarence; Crucian, Brian; Stowe, Raymond; Pierson, Duane; Mehta, Satish; Morukov, Boris; Uchakin, Peter; Nehlsen-Cannarella, Sandra

    2008-01-01

    Validation of Procedures for Monitoring Crew Member Immune Function - Short Duration Biological Investigation (Integrated Immune-SDBI) will assess the clinical risks resulting from the adverse effects of space flight on the human immune system and will validate a flightcompatible immune monitoring strategy. Immune system changes will be monitored by collecting and analyzing blood, urine and saliva samples from crewmembers before, during and after space flight.

  20. Synthetic and Biological Studies of Sesquiterpene Polygodial: Activity of 9-Epipolygodial Against Drug Resistant Cancer Cells

    Science.gov (United States)

    Dasari, Ramesh; De Carvalho, Annelise; Medellin, Derek C.; Middleton, Kelsey N.; Hague, Frédéric; Volmar, Marie N. M.; Frolova, Liliya V.; Rossato, Mateus F.; De La Chapa, Jorge J.; Dybdal-Hargreaves, Nicholas F.; Pillai, Akshita; Mathieu, Véronique; Rogelj, Snezna; Gonzales, Cara B.; Calixto, João B.; Evidente, Antonio; Gautier, Mathieu; Munirathinam, Gnanasekar; Glass, Rainer; Burth, Patricia; Pelly, Stephen C.; van Otterlo, Willem A. L.; Kiss, Robert; Kornienko, Alexander

    2015-01-01

    Polygodial, a terpenenoid dialdehyde isolated from Polygonum hydropiper L., is a known TRPV1 agonist. In this investigation a series of polygodial analogues were prepared and investigated for TRPV1 agonistic and anticancer activities. These experiments led to the identification of 9-epipolygodial, possessing antiproliferative potency significantly exceeding that of polygodial. Epipolygodial maintained potency against apoptosis-resistant cancer cells as well as those displaying the MDR phenotype. In addition, a chemical feasibility for the previously proposed mechanism of action of polygodial, involving the Paal-Knorr pyrrole formation with a lysine residue on the target protein, was demonstrated through the synthesis of a stable polygodial pyrrole derivative. These studies reveal rich chemical and biological properties associated with polygodial and its direct derivatives. They should inspire further work in this area aimed at the development of new pharmacological agents or exploration of novel mechanisms of covalent modification of biological molecules with natural products. PMID:26434977

  1. Assessment of the electrochemical effects of pulsed electric fields in a biological cell suspension.

    Science.gov (United States)

    Chafai, Djamel Eddine; Mehle, Andraž; Tilmatine, Amar; Maouche, Bachir; Miklavčič, Damijan

    2015-12-01

    Electroporation of cells is successfully used in biology, biotechnology and medicine. Practical problems still arise in the electroporation of cells in suspension. For example, the determination of cell electroporation is still a demanding and time-consuming task. Electric pulses also cause contamination of the solution by the metal released from the electrodes and create local enhancements of the electric field, leading to the occurrence of electrochemical reactions at the electrode/electrolyte interface. In our study, we investigated the possibility of assessing modifications to the cell environment caused by pulsed electric fields using electrochemical impedance spectroscopy. We designed an experimental protocol to elucidate the mechanism by which a pulsed electric field affects the electrode state in relation to different electrolyte conductivities at the interface. The results show that a pulsed electric field affects electrodes and its degree depends on the electrolyte conductivity. Evolution of the electrochemical reaction rate depends on the initial free charges and those generated by the pulsed electric field. In the presence of biological cells, the initial free charges in the medium are reduced. The electrical current path at low frequency is longer, i.e., conductivity is decreased, even in the presence of increased permeability of the cell membrane created by the pulsed electric field.

  2. Biological Effects of Osteoblast-Like Cells on Nanohydroxyapatite Particles at a Low Concentration Range

    Directory of Open Access Journals (Sweden)

    Xiaochen Liu

    2011-01-01

    Full Text Available The biological effects of osteoblast-like MG-63 cells on nanohydroxyapatite (n-HA at the low concentration range (5–25 g/mL for 5 days was investigated. The results showed the viability and actin cytoskeleton of the cells descended with the increase of the concentration of n-HA, and the actin cytoskeleton of cells was depolymerised and became more disordered. Apoptotic rate of cells (1.85%, 1.99%, and 2.29% increased with the increase of n-HA concentration (5, 15, and 25 g/mL and become significantly higher than the control. Total intracellular protein content decreased with n-HA concentration increase, showing significant difference between 25 g/mL and the control, and no significant change of ALP activity was observed at the 5th day. The results revealed that the cell growth was inhibited by n-HA in a concentration-dependent manner, and the obvious biological effects of MG-63 cells on n-HA existed at the low concentration range from 5 to 25 g/mL.

  3. The untapped cell biology of neglected tropical diseases

    Science.gov (United States)

    Sullivan, William

    2016-01-01

    The World Health Organization lists a constellation of 17 tropical diseases that afflict approximately one in six individuals on the planet and, until recently, few resources have been devoted to the treatment and eradication of those diseases. They are often referred to as the diseases of the “bottom billion,” because they are most prevalent among the poorest individuals in impoverished tropical nations. However, the few studies that have been performed reveal an extraordinary world of molecular and cellular adaptations that facilitate the pathogens’ survival in hosts ranging from insects to humans. A compelling case can be made that even a modest investment toward understanding the basic molecular and cell biology of these neglected pathogens has a high probability of yielding exciting new cellular mechanisms and insights into novel ways of combating these diseases. PMID:26915691

  4. Towards Modelling and Simulation of Crowded Environments in Cell Biology

    Science.gov (United States)

    Bittig, Arne T.; Jeschke, Matthias; Uhrmacher, Adelinde M.

    2010-09-01

    In modelling and simulation of cell biological processes, spatial homogeneity in the distribution of components is a common but not always valid assumption. Spatial simulation methods differ in computational effort and accuracy, and usually rely on tool-specific input formats for model specification. A clear separation between modelling and simulation allows a declarative model specification thereby facilitating reuse of models and exploiting different simulators. We outline a modelling formalism covering both stochastic spatial simulation at the population level and simulation of individual entities moving in continuous space as well as the combination thereof. A multi-level spatial simulator is presented that combines populations of small particles simulated according to the Next Subvolume Method with individually represented large particles following Brownian motion. This approach entails several challenges that need to be overcome, but nicely balances between calculation effort and required levels of detail.

  5. Biological character of human adipose-derived adult stem cells and influence of donor age on cell replication in culture

    Institute of Scientific and Technical Information of China (English)

    LEI Lei; LIAO WeiMing; SHENG PuYi; FU Ming; HE AiShan; HUANG Gang

    2007-01-01

    To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell's replication activity and the donor's age factor, and to assess the stem cells as a new source for tissue engineering, hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: <20 years old, 21-40years old, 41-60 years old and >61 years old groups). The protein markers (CD29, CD34, CD44, CD45,CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell,and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro.The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula "TD = t log2/logNt - logN0 "was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the <20 years old group was lower than that of the >61 years old group (statistical analysis of variance (ANOVA), P=-0.002, P<0.05). These findings suggested that a higher level of hADAS cells replication activity was found in the younger donators, and they represent novel and valuable seed cells for studies of tissue engineering.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-01

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

  7. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    OpenAIRE

    Matthew Emerson Randolph; Pavlath, Grace K.

    2015-01-01

    The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in t...

  8. Rewiring cells: synthetic biology as a tool to interrogate the organizational principles of living systems.

    Science.gov (United States)

    Bashor, Caleb J; Horwitz, Andrew A; Peisajovich, Sergio G; Lim, Wendell A

    2010-01-01

    The living cell is an incredibly complex entity, and the goal of predictively and quantitatively understanding its function is one of the next great challenges in biology. Much of what we know about the cell concerns its constituent parts, but to a great extent we have yet to decode how these parts are organized to yield complex physiological function. Classically, we have learned about the organization of cellular networks by disrupting them through genetic or chemical means. The emerging discipline of synthetic biology offers an additional, powerful approach to study systems. By rearranging the parts that comprise existing networks, we can gain valuable insight into the hierarchical logic of the networks and identify the modular building blocks that evolution uses to generate innovative function. In addition, by building minimal toy networks, one can systematically explore the relationship between network structure and function. Here, we outline recent work that uses synthetic biology approaches to investigate the organization and function of cellular networks, and describe a vision for a synthetic biology toolkit that could be used to interrogate the design principles of diverse systems.

  9. Neutron Exposures in Human Cells: Bystander Effect and Relative Biological Effectiveness

    Science.gov (United States)

    Seth, Isheeta; Schwartz, Jeffrey L.; Stewart, Robert D.; Emery, Robert; Joiner, Michael C.; Tucker, James D.

    2014-01-01

    Bystander effects have been observed repeatedly in mammalian cells following photon and alpha particle irradiation. However, few studies have been performed to investigate bystander effects arising from neutron irradiation. Here we asked whether neutrons also induce a bystander effect in two normal human lymphoblastoid cell lines. These cells were exposed to fast neutrons produced by targeting a near-monoenergetic 50.5 MeV proton beam at a Be target (17 MeV average neutron energy), and irradiated-cell conditioned media (ICCM) was transferred to unirradiated cells. The cytokinesis-block micronucleus assay was used to quantify genetic damage in radiation-naïve cells exposed to ICCM from cultures that received 0 (control), 0.5, 1, 1.5, 2, 3 or 4 Gy neutrons. Cells grown in ICCM from irradiated cells showed no significant increase in the frequencies of micronuclei or nucleoplasmic bridges compared to cells grown in ICCM from sham irradiated cells for either cell line. However, the neutron beam has a photon dose-contamination of 5%, which may modulate a neutron-induced bystander effect. To determine whether these low doses of contaminating photons can induce a bystander effect, cells were irradiated with cobalt-60 at doses equivalent to the percent contamination for each neutron dose. No significant increase in the frequencies of micronuclei or bridges was observed at these doses of photons for either cell line when cultured in ICCM. As expected, high doses of photons induced a clear bystander effect in both cell lines for micronuclei and bridges (pbystander effect in these cells. Finally, neutrons had a relative biological effectiveness of 2.0±0.13 for micronuclei and 5.8±2.9 for bridges compared to cobalt-60. These results may be relevant to radiation therapy with fast neutrons and for regulatory agencies setting standards for neutron radiation protection and safety. PMID:24896095

  10. Neutron exposures in human cells: bystander effect and relative biological effectiveness.

    Science.gov (United States)

    Seth, Isheeta; Schwartz, Jeffrey L; Stewart, Robert D; Emery, Robert; Joiner, Michael C; Tucker, James D

    2014-01-01

    Bystander effects have been observed repeatedly in mammalian cells following photon and alpha particle irradiation. However, few studies have been performed to investigate bystander effects arising from neutron irradiation. Here we asked whether neutrons also induce a bystander effect in two normal human lymphoblastoid cell lines. These cells were exposed to fast neutrons produced by targeting a near-monoenergetic 50.5 MeV proton beam at a Be target (17 MeV average neutron energy), and irradiated-cell conditioned media (ICCM) was transferred to unirradiated cells. The cytokinesis-block micronucleus assay was used to quantify genetic damage in radiation-naïve cells exposed to ICCM from cultures that received 0 (control), 0.5, 1, 1.5, 2, 3 or 4 Gy neutrons. Cells grown in ICCM from irradiated cells showed no significant increase in the frequencies of micronuclei or nucleoplasmic bridges compared to cells grown in ICCM from sham irradiated cells for either cell line. However, the neutron beam has a photon dose-contamination of 5%, which may modulate a neutron-induced bystander effect. To determine whether these low doses of contaminating photons can induce a bystander effect, cells were irradiated with cobalt-60 at doses equivalent to the percent contamination for each neutron dose. No significant increase in the frequencies of micronuclei or bridges was observed at these doses of photons for either cell line when cultured in ICCM. As expected, high doses of photons induced a clear bystander effect in both cell lines for micronuclei and bridges (pbystander effect in these cells. Finally, neutrons had a relative biological effectiveness of 2.0 ± 0.13 for micronuclei and 5.8 ± 2.9 for bridges compared to cobalt-60. These results may be relevant to radiation therapy with fast neutrons and for regulatory agencies setting standards for neutron radiation protection and safety.

  11. Microscopy Images as Interactive Tools in Cell Modeling and Cell Biology Education

    Science.gov (United States)

    Araujo-Jorge, Tania C.; Cardona, Tania S.; Mendes, Claudia L. S.; Henriques-Pons, Andrea; Meirelles, Rosane M. S.; Coutinho, Claudia M. L. M.; Aguiar, Luiz Edmundo V.; Meirelles, Maria de Nazareth L.; de Castro, Solange L.; Barbosa, Helene S.; Luz, Mauricio R. M. P.

    2004-01-01

    The advent of genomics, proteomics, and microarray technology has brought much excitement to science, both in teaching and in learning. The public is eager to know about the processes of life. In the present context of the explosive growth of scientific information, a major challenge of modern cell biology is to popularize basic concepts of…

  12. Glucose Transport in Cultured Animal Cells: An Exercise for the Undergraduate Cell Biology Laboratory

    Science.gov (United States)

    Ledbetter, Mary Lee S.; Lippert, Malcolm J.

    2002-01-01

    Membrane transport is a fundamental concept that undergraduate students of cell biology understand better with laboratory experience. Formal teaching exercises commonly used to illustrate this concept are unbiological, qualitative, or intricate and time consuming to prepare. We have developed an exercise that uses uptake of radiolabeled nutrient…

  13. Glucose Transport in Cultured Animal Cells: An Exercise for the Undergraduate Cell Biology Laboratory

    Science.gov (United States)

    Ledbetter, Mary Lee S.; Lippert, Malcolm J.

    2002-01-01

    Membrane transport is a fundamental concept that undergraduate students of cell biology understand better with laboratory experience. Formal teaching exercises commonly used to illustrate this concept are unbiological, qualitative, or intricate and time consuming to prepare. We have developed an exercise that uses uptake of radiolabeled nutrient…

  14. Waveguide evanescent field fluorescence microscopy & its application in cell biology

    Science.gov (United States)

    Hassanzadeh, Abdollah

    There are many powerful microscopy technologies available for the investigation of bulk materials as well as for thin film samples. Nevertheless, for imaging an interface, especially live cells on a substrate and ultra thin-films, only Total Internal Reflection Fluorescence (TIRF) microscopy is available. This TIRF microscopy allows imaging without interference of the bulk. Various approaches are employed in fluorescence microscopy applications to restrict the excitation and detection of fluorophores to a thin region of the specimen. Elimination of background fluorescence from outside the focal plane can dramatically improve the signal-to-noise ratio, and consequently, the spatial resolution of the features or events of interest. TIRF microscopy is an evanescent field based microscopy. In this method, fluorescent dyes are only excited within an evanescent field: roughly within 100 nm above a glass coverslip. This will allow imaging surface and interfacial issues of the glass coverslip and an adjacent material. Waveguide evanescent field fluorescence (WEFF) microscopy is a new development for imaging cell-substrate interactions in real time and in vitro. It is an alternative to TIRF microscopy. In this method the light is coupled into a waveguide via an optical grating. The coupled light propagates as a waveguide mode and exhibits an evanescent field on top of the waveguide. This can be used as a surface-bound illumination source to excite fluorophores. This evanescent field serves as an extremely powerful tool for quality control of thin films, to study cell-substrate contacts, and investigating the effect of external agents and drugs on the cell-substrate interaction in real time and in vitro. This new method has been established and optimized to minimize non-uniformity, scattering and photo bleaching issues. Visualizing and quantifying of the cell-substrates and solid thin films have been carried out by WEFF microscopy. The images of the cell-substrate interface

  15. Mesenchymal Stem Cells as a Biological Drug for Heart Disease: Where Are We With Cardiac Cell-Based Therapy?

    Science.gov (United States)

    Sanina, Cristina; Hare, Joshua M

    2015-07-17

    Cell-based treatment represents a new generation in the evolution of biological therapeutics. A prototypic cell-based therapy, the mesenchymal stem cell, has successfully entered phase III pivotal trials for heart failure, signifying adequate enabling safety and efficacy data from phase I and II trials. Successful phase III trials can lead to approval of a new biological therapy for regenerative medicine.

  16. Workshop on "What do you need to know about doing cell biology experiments in space?".

    Science.gov (United States)

    2004-03-01

    The "What do you need to know about doing cell biology experiments in space?" workshop represented a continued international collaboration between cell culture hardware developers and scientists, partly due to the enhanced collaboration in space life sciences spurred on by the International Space Life Sciences Working Group. The workshop was organized into three sessions. The first session provided an overview of the general effects of space flight, including definition of the microgravity environment, the radiation environment, and issues surrounding mass transport. The session concluded with an important overview of using space centrifuges as Earth gravity (1-g) controls, including understanding the contribution of inertial shear forces. The second session described existing and planned hardware facilities developed to support cell culture research, ranging from small hand-held hardware to breadbox-sized Shuttle middeck hardware to complete facility racks. Hardware designed for use on the Shuttle, ISS, and in free flyers was described. The third session provided advice from experienced space flight cell biology principal investigators to new investigators in the field. This special issue of the Journal of Gravitational Physiology includes externally peer-reviewed papers from all three sessions.

  17. Development of an autonomous biological cell manipulator with single-cell electroporation and visual servoing capabilities.

    Science.gov (United States)

    Sakaki, Kelly; Dechev, Nikolai; Burke, Robert D; Park, Edward J

    2009-08-01

    Studies of single cells via microscopy and microinjection are a key component in research on gene functions, cancer, stem cells, and reproductive technology. As biomedical experiments become more complex, there is an urgent need to use robotic systems to improve cell manipulation and microinjection processes. Automation of these tasks using machine vision and visual servoing creates significant benefits for biomedical laboratories, including repeatability of experiments, higher throughput, and improved cell viability. This paper presents the development of a new 5-DOF robotic manipulator, designed for manipulating and microinjecting single cells. This biological cell manipulator (BCM) is capable of autonomous scanning of a cell culture followed by autonomous injection of cells using single-cell electroporation (SCE). SCE does not require piercing the cell membrane, thereby keeping the cell membrane fully intact. The BCM features high-precision 3-DOF translational and 2-DOF rotational motion, and a second z-axis allowing top-down placement of a micropipette tip onto the cell membrane for SCE. As a technical demonstration, the autonomous visual servoing and microinjection capabilities of the single-cell manipulator are experimentally shown using sea urchin eggs.

  18. A cell-based systems biology assessment of human blood to monitor immune responses after influenza vaccination.

    Science.gov (United States)

    Hoek, Kristen L; Samir, Parimal; Howard, Leigh M; Niu, Xinnan; Prasad, Nripesh; Galassie, Allison; Liu, Qi; Allos, Tara M; Floyd, Kyle A; Guo, Yan; Shyr, Yu; Levy, Shawn E; Joyce, Sebastian; Edwards, Kathryn M; Link, Andrew J

    2015-01-01

    Systems biology is an approach to comprehensively study complex interactions within a biological system. Most published systems vaccinology studies have utilized whole blood or peripheral blood mononuclear cells (PBMC) to monitor the immune response after vaccination. Because human blood is comprised of multiple hematopoietic cell types, the potential for masking responses of under-represented cell populations is increased when analyzing whole blood or PBMC. To investigate the contribution of individual cell types to the immune response after vaccination, we established a rapid and efficient method to purify human T and B cells, natural killer (NK) cells, myeloid dendritic cells (mDC), monocytes, and neutrophils from fresh venous blood. Purified cells were fractionated and processed in a single day. RNA-Seq and quantitative shotgun proteomics were performed to determine expression profiles for each cell type prior to and after inactivated seasonal influenza vaccination. Our results show that transcriptomic and proteomic profiles generated from purified immune cells differ significantly from PBMC. Differential expression analysis for each immune cell type also shows unique transcriptomic and proteomic expression profiles as well as changing biological networks at early time points after vaccination. This cell type-specific information provides a more comprehensive approach to monitor vaccine responses.

  19. Biological character of human adipose-derived adult stem cells and influence of donor age on cell replication in culture

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell’s replication activity and the donor’s age factor, and to assess the stem cells as a new source for tissue engineering. hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: <20 years old, 21―40 years old, 41―60 years old and >61 years old groups). The protein markers (CD29, CD34, CD44, CD45, CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell, and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro. The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula “ log2T D = t logN t ? logN 0” was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the <20 years old group was lower than that of the >61 years old group (statistical analysis of variance (ANOVA), P=0.002, P<0.05). These find- ings suggested that a higher level of hADAS cells replication activity was found in the younger dona- tors, and they represent novel and valuable seed cells for studies of tissue engineering.

  20. Student Perceptions of the Cell Biology Laboratory Learning Environment in Four Undergraduate Science Courses in Spain

    Science.gov (United States)

    De Juan, Joaquin; Pérez-Cañaveras, Rosa M.; Segovia, Yolanda; Girela, Jose Luis; Martínez-Ruiz, Noemi; Romero-Rameta, Alejandro; Gómez-Torres, Maria José; Vizcaya-Moreno, M. Flores

    2016-01-01

    Cell biology is an academic discipline that organises and coordinates the learning of the structure, function and molecular composition of cells in some undergraduate biomedical programs. Besides course content and teaching methodologies, the laboratory environment is considered a key element in the teaching of and learning of cell biology. The…

  1. Student Perceptions of the Cell Biology Laboratory Learning Environment in Four Undergraduate Science Courses in Spain

    Science.gov (United States)

    De Juan, Joaquin; Pérez-Cañaveras, Rosa M.; Segovia, Yolanda; Girela, Jose Luis; Martínez-Ruiz, Noemi; Romero-Rameta, Alejandro; Gómez-Torres, Maria José; Vizcaya-Moreno, M. Flores

    2016-01-01

    Cell biology is an academic discipline that organises and coordinates the learning of the structure, function and molecular composition of cells in some undergraduate biomedical programs. Besides course content and teaching methodologies, the laboratory environment is considered a key element in the teaching of and learning of cell biology. The…

  2. Biological effects of simulated microgravity on human umbilical vein endothelial cell line HUVEC-C

    Science.gov (United States)

    Liu, Ming; Cheng, Zhenlong; Liang, Shujian; Sun, Yeqing

    Microgravity has been reported to have multiple influences on human cells. To investigate the biological effects of simulated microgravity on human endothelial cells, human umbilical vein endothelial cell HUVEC-C was treated with microgravity for 24 hours and restored at 1 g gravity for extra 24 hours (group 1) and 48 hours and restored for 24 hours (group 2). Microgravity was simulated by using a two-dimensionally rotating clinostat, set on 30 rpm. As controls, cells were cultured paralleled at 1 g gravity. Two groups of treated cells and control cells were harvested at 0, 12, 24, 48 and 72 (for group 2 and control only) hours for proliferation, cell cycles, apoptosis, proteome and microarray analysis. The influences of microgravity on cell proliferation were controversial in previous reports, and in our experiment, inhibitory effect was observed at 12 hour, and cell number of the treatment groups presented 9.26% decrease compared with that of control. Cell cycle distribution was analyzed using flow cytometry. The G2/M cell cycle arrest also occurred at 12 hour in both treatment groups, the cell rates at G2/M phase were 24% higher than in control. Effect of simulated microgravity on cell apoptosis was observed only after 48-hour-treatment, resulted in percentage of apoptotic cells increased by 53-67% compared with control. After cells returned to normal conditions for 24 hours, levels of cell proliferation, cell cycle and cell apoptosis in treatment groups were comparable to control. In order to investigate the molecular mechanism, we analyzed the treated cells at proteomic and transcriptomic levels respectively. Two-dimensional electrophoresis showed that after 24- hour-restoration under normal conditions, 189 proteins in control group disappeared and 187 new proteins presented in group 1; 469 proteins disappeared and 291 new proteins presented in group 2. By using microarray, we found that expression levels of 56 genes were up-regulated and 45 down-regulated in

  3. History of the Department of Cell Biology at Yale School of Medicine, 1813-2010.

    Science.gov (United States)

    Lentz, Thomas L

    2011-06-01

    The Department of Cell Biology at the Yale University School of Medicine was established in 1983. It was preceded by the Section of Cell Biology, which was formed in 1973 when George E. Palade and collaborators came to Yale from the Rockefeller University. Cell Biology at Yale had its origins in the Department of Anatomy that existed from the beginning of classes at the Medical Institution of Yale College in 1813. This article reviews the history of the Department of Anatomy at Yale and its evolution into Cell Biology that began with the introduction of histology into the curriculum in the 1860s. The formation and development of the Section and Department of Cell Biology in the second half of the 20th century to the present time are described. Biographies and research activities of the chairs and key faculty in anatomy and cell biology are provided.

  4. Accumulation and biological effects of cobalt ferrite nanoparticles in human pancreatic and ovarian cancer cells.

    Science.gov (United States)

    Pašukonienė, Vita; Mlynska, Agata; Steponkienė, Simona; Poderys, Vilius; Matulionytė, Marija; Karabanovas, Vitalijus; Statkutė, Urtė; Purvinienė, Rasa; Kraśko, Jan Aleksander; Jagminas, Arūnas; Kurtinaitienė, Marija; Strioga, Marius; Rotomskis, Ričardas

    2014-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) emerge as a promising tool for early cancer diagnostics and targeted therapy. However, both toxicity and biological activity of SPIONs should be evaluated in detail. The aim of this study was to synthesize superparamagnetic cobalt ferrite nanoparticles (Co-SPIONs), and to investigate their uptake, toxicity and effects on cancer stem-like properties in human pancreatic cancer cell line MiaPaCa2 and human ovarian cancer cell line A2780. Co-SPIONs were produced by Massart's co-precipitation method. The cells were treated with Co-SPIONs at three different concentrations (0.095, 0.48, and 0.95μg/mL) for 24 and 48h. Cell viability and proliferation were analyzed after treatment. The stem-like properties of cells were assessed by investigating the cell clonogenicity and expression of cancer stem cell-associated markers, including CD24/ESA in A2780 cell line and CD44/ALDH1 in MiaPaCa2 cell line. Magnetically activated cell sorting was used for the separation of magnetically labeled and unlabeled cells. Both cancer cell lines accumulated Co-SPIONs, however differences in response to nanoparticles were observed between MiaPaCa2 and A2780 cell. In particular, A2780 cells were more sensitive to exposition to Co-SPIONs than MiaPaCa2 cells, indicating that a safe concentration of nanoparticles must be estimated individually for a particular cell type. Higher doses of Co-SPIONs decreased both the clonogenicity and ESA marker expression in A2780 cells. Co-SPIONs are not cytotoxic to cancer cells, at least when used at a concentration of up to 0.95μg/mL. Co-SPIONs have a dose-dependent effect on the clonogenic potential and ESA marker expression in A2780 cells. Magnetic detection of low concentrations of Co-SPIONS in cancer cells is a promising tool for further applications of these nanoparticles in cancer diagnosis and treatment; however, extensive research in this field is needed. Copyright © 2014 Lithuanian University of

  5. Investigation of Cadmium Selenide Photoelectrochemical Cells.

    Science.gov (United States)

    1980-01-01

    au xinon gmettant un rayonnement de composition spectrale tras comparable A celle de la lumiare solaire correspondant a des conditions MAl (masse de...important. The irradiance at ground level depends on solar elevation and atmospheric conditions. The atmosphere absorbs solar radiation (e.g. by H20, 03...CO2 and other minor constituents) and scatters solar radiation (e.g. Rayleigh and aerosol scattering). The path length through the atmosphere is

  6. The Comparison of Biologic Characteristics between Mice Embryonic Stem Cells and Bone Marrow Derived Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Junfeng Liu; Zhixu He; Dong Shen; Jin Huang; Haowen Wang

    2009-01-01

    OBJECTIVE This research was to induce dendritic cells (DCs)from mice embryonic stem cells and bone marrow mononuclear cells in vitro, and then compare the biologic characteristics of them.METHODS Embryonic stem cells (ESCs) suspending cultured in petri dishes were induced to generate embryonic bodies (EBs).Fourteen-day well-developed EBs were transferred to histological culture with the same medium and supplemented 25 ng/ml GM-CSF and 25 ng/ml IL-3. In the next 2 weeks, there were numerous immature DCs outgrown. Meantime, mononuclear cells isolated from mice bone marrow were induced to derive dendritic cells by supplementing 25 ng/ml GM-CSF and 25 ng/ml IL-4, and then the morphology, phenotype and function of both dendritic cells from different origins were examined.RESULTS Growing mature through exposure to lipopolysaccharide (LPS), both ESC-DCs and BM-DCs exhibited dramatic veils of cytoplasm and extensive dendrites on their surfaces, highly expressed CD11c, MHC-Ⅱ and CD86 with strong capacity to stimulate primary T cell responses in mixed leukocyte reaction (MLR).CONCLUSION ESC-DC has the same biologic characteristics as BM-DC, and it provides a new, reliable source for the functional research of DC and next produce corresponding anti-tumor vaccine.

  7. Electromechanics: An analytic solution for graded biological cell.

    Science.gov (United States)

    Chan, Kin Lok; Yu, K. W.

    2007-03-01

    Electromechanics of graded material has been established recently to study the effective response of inhomogeneous graded spherical particles under an external ac electric field.[1, 2]Such particles having a complex dielectric profile varies along the radius of the particles. The gradation in the colloidal particles is modeled by assuming both the dielectric and conductivity vary along the radius. More precisely, both the dielectric and conductivity function are assumed to be a isotopic linear function dependence on the radius variable r, namely, ɛ(r)=ɛ(0)+A1r, σ(r)=σ(0)+A2r.In this talk, we will present the exact analytical solutions of the dipole moment of such particle in terms of the hypergeometric functions, and the effective electric response in dilute limit. Moreover, we applied the dielectric dispersion spectral representation (DDSR) to study the Debye Behavior of the cell. Our exact results may be applied to graded biological cell suspensions, as their interior must be inhomogeneous in nature. [1] En-Bo Wei, L. Dong, K. W. Yu, Journal of Applied Physics 99, 054101(2006) [2] L. Dong, Mikko Karttunen, K. W. Yu, Phys. Rev. E, Vol. 72, art. no. 016613 (2005)

  8. Statins as Modulators of Regulatory T-Cell Biology

    Directory of Open Access Journals (Sweden)

    David A. Forero-Peña

    2013-01-01

    Full Text Available Statins are pharmacological inhibitors of the activity of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR, an enzyme responsible for the synthesis of cholesterol. Some recent experimental studies have shown that besides their effects on the primary and secondary prevention of cardiovascular diseases, statins may also have beneficial anti-inflammatory effects through diverse mechanisms. On the other hand, the induction and activity of regulatory T cells (Treg are key processes in the prevention of pathology during chronic inflammatory and autoimmune diseases. Hence, strategies oriented towards the therapeutic expansion of Tregs are gaining special attention among biomedical researchers. The potential effects of statins on the biology of Treg are of particular importance because of their eventual application as in vivo inducers of Treg in the treatment of multiple conditions. In this paper we review the experimental evidence pointing out to a potential effect of statins on the role of regulatory T cells in different conditions and discuss its potential clinical significance.

  9. In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine.

    Science.gov (United States)

    Pi, Jiang; Jin, Hua; Yang, Fen; Chen, Zheng W; Cai, Jiye

    2014-11-01

    The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In

  10. Investigation of adhesion and mechanical properties of human glioma cells by single cell force spectroscopy and atomic force microscopy.

    Science.gov (United States)

    Andolfi, Laura; Bourkoula, Eugenia; Migliorini, Elisa; Palma, Anita; Pucer, Anja; Skrap, Miran; Scoles, Giacinto; Beltrami, Antonio Paolo; Cesselli, Daniela; Lazzarino, Marco

    2014-01-01

    Active cell migration and invasion is a peculiar feature of glioma that makes this tumor able to rapidly infiltrate into the surrounding brain tissue. In our recent work, we identified a novel class of glioma-associated-stem cells (defined as GASC for high-grade glioma--HG--and Gasc for low-grade glioma--LG) that, although not tumorigenic, act supporting the biological aggressiveness of glioma-initiating stem cells (defined as GSC for HG and Gsc for LG) favoring also their motility. Migrating cancer cells undergo considerable molecular and cellular changes by remodeling their cytoskeleton and cell interactions with surrounding environment. To get a better understanding about the role of the glioma-associated-stem cells in tumor progression, cell deformability and interactions between glioma-initiating stem cells and glioma-associated-stem cells were investigated. Adhesion of HG/LG-cancer cells on HG/LG-glioma-associated stem cells was studied by time-lapse microscopy, while cell deformability and cell-cell adhesion strengths were quantified by indentation measurements by atomic force microscopy and single cell force spectroscopy. Our results demonstrate that for both HG and LG glioma, cancer-initiating-stem cells are softer than glioma-associated-stem cells, in agreement with their neoplastic features. The adhesion strength of GSC on GASC appears to be significantly lower than that observed for Gsc on Gasc. Whereas, GSC spread and firmly adhere on Gasc with an adhesion strength increased as compared to that obtained on GASC. These findings highlight that the grade of glioma-associated-stem cells plays an important role in modulating cancer cell adhesion, which could affect glioma cell migration, invasion and thus cancer aggressiveness. Moreover this work provides evidence about the importance of investigating cell adhesion and elasticity for new developments in disease diagnostics and therapeutics.

  11. Investigation of adhesion and mechanical properties of human glioma cells by single cell force spectroscopy and atomic force microscopy.

    Directory of Open Access Journals (Sweden)

    Laura Andolfi

    Full Text Available Active cell migration and invasion is a peculiar feature of glioma that makes this tumor able to rapidly infiltrate into the surrounding brain tissue. In our recent work, we identified a novel class of glioma-associated-stem cells (defined as GASC for high-grade glioma--HG--and Gasc for low-grade glioma--LG that, although not tumorigenic, act supporting the biological aggressiveness of glioma-initiating stem cells (defined as GSC for HG and Gsc for LG favoring also their motility. Migrating cancer cells undergo considerable molecular and cellular changes by remodeling their cytoskeleton and cell interactions with surrounding environment. To get a better understanding about the role of the glioma-associated-stem cells in tumor progression, cell deformability and interactions between glioma-initiating stem cells and glioma-associated-stem cells were investigated. Adhesion of HG/LG-cancer cells on HG/LG-glioma-associated stem cells was studied by time-lapse microscopy, while cell deformability and cell-cell adhesion strengths were quantified by indentation measurements by atomic force microscopy and single cell force spectroscopy. Our results demonstrate that for both HG and LG glioma, cancer-initiating-stem cells are softer than glioma-associated-stem cells, in agreement with their neoplastic features. The adhesion strength of GSC on GASC appears to be significantly lower than that observed for Gsc on Gasc. Whereas, GSC spread and firmly adhere on Gasc with an adhesion strength increased as compared to that obtained on GASC. These findings highlight that the grade of glioma-associated-stem cells plays an important role in modulating cancer cell adhesion, which could affect glioma cell migration, invasion and thus cancer aggressiveness. Moreover this work provides evidence about the importance of investigating cell adhesion and elasticity for new developments in disease diagnostics and therapeutics.

  12. On the dielectric relaxation of biological cell suspensions: the effect of the membrane electrical conductivity.

    Science.gov (United States)

    Di Biasio, A; Cametti, C

    2011-06-01

    Due to the mismatch of the electrical parameters (the permittivity ϵ' and the electrical conductivity σ) of the membrane of a biological cell with the ones of the cytosol and the extracellular medium, biological cell suspensions are the site, under the influence of an external electric field, of large dielectric relaxations in the radiowave frequency range. However, a point still remains controversial, i.e., whether or not the value of membrane conductivity σ(s) might be extracted from the de-convolution of the dielectric spectra or otherwise if it would be more reasonable to assign to the membrane conductivity a value equal to zero. This point is not to be considered with superficiality since it concerns an a priori choice which ultimately influences the values of the electrical parameters deduced from this technique. As far as this point is concerned, the opinion of the researchers in this field diverges. We believe that, at least within certain limits, the membrane conductivity can be deduced from the shape of the relaxation spectra. We substantiate this thesis with two different examples concerning the first a suspension of human normal erythrocyte cells and the second a suspension of human lymphocyte cells. In both cases, by means of an accurate fitting procedure based on the Levenberg-Marquardt method for complex functions, we can evaluate the membrane conductivity σ(s) with its associated uncertainty. The knowledge of the membrane electrical conductivity will favor the investigation of different ion transport mechanisms across the cell membrane.

  13. Biological characteristics of breast carcinomas with neuroendocrine cell differentiation

    Institute of Scientific and Technical Information of China (English)

    姚根有; 周吉林; 赵仲生; 阮俊

    2004-01-01

    Background The aim of this study was to investigate DNA content and expression of c-erbB-2, PS2, and prostate-specific antigen (PSA) proteins in breast carcinomas with neuroendocrine (NE) cell differentiation.Methods Chromogranin, c-erbB-2, PS2, and PSA in 131 samples of breast cancer were detected immunohistochemically. Classic Feulgen staining image analysis techniques were used to quantify DNA content in 81 of the breast cancer samples.Results The c-erbB-2 positive rate in breast carcinoma samples containing neuroendocrine cells was 37.5% and the rate of high expression of c-erbB-2 (++ or +++) was 33.3%, both significantly lower than that in breast carcinomas without neuroendocrine cells (62.6% and 68.7%, respectively, P 5c aneuploidy cells, and rate of aneuploidy among cells were all lower than that in NE (-) breast carcinomas (P<0.01). In NE (+) grade I or II breast carcinomas, these indices were also all lower than that in the NE (-) breast carcinoma samples (P<0.01).Conclusion Breast carcinomas with neuroendocrine differentiation have a lower rate of malignancy. Neuroendocrine differentiation could serve as a prognostic marker in clinical practice.

  14. Biological characterization of cultured dermal papilla cells and hair follicle regeneration in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    Lü Zhong-fa; CAI Sui-qing; WU Jin-jin; ZHENG Min

    2006-01-01

    Background Dermal papilla cells (DPC) are a group of mesenchyme-derived cells at the base of the hair follicle, where they regulate and control hair follicle growth through the expression and secretion of cytokines. Nevertheless, the role of DPC derived chemokines and other cytokines in the hair follicle biology remain speculative. In this study, we investigated the expression of basic fibroblast growth factor (bFGF), endothelin-1 (ET-1) and stem cell factor (SCF) in different passages of cultured DPC and their effects on the biological behaviour of DPC.Methods The expression of bFGF, ET-1 and SCF in different passages of cultured DPC and their possible effects on the biological behavior of DPC are investigated using in situ hybridization and immunochemistry. In addition, we performed transplantation of hair follicle cells into nude mice. The cultured DPC, dermal sheath cells and fibroblast of human scalp, respectively, were mixed with cells of the hair follicle epithelium in different ratios, and then were cultured in hair follicle organotypic cultures or implanted into the subcutis of nude mice.Results The expression of ET-1 and SCF in early passages of cultured DPC became stronger, but turned weaker and even negative in late passages (>6 passages). Hair follicle-like structures were formed after DPC combined with the cells of hair follicle epithelium cells in hair follicle organotypic cultures. When hair follicle organotypic cultures were implanted into the subcutis of nude mice, the relative intact hair follicles were formed. After the transplantation of hair follicle cells into the nude mice, the hair follicle-like structure was formed in the group that contained DPC mixed with hair follicle epithelium cells. However, no hair follicles were formed in the other two groups. It was found that the higher the expression of ET-1 and SCF in DPC, the stronger the ability of DPC to induce hair follicle regeneration.Conclusions The cultured DPC can induce hair follicle

  15. From microbiology to cell biology: when an intracellular bacterium becomes part of its host cell.

    Science.gov (United States)

    McCutcheon, John P

    2016-08-01

    Mitochondria and chloroplasts are now called organelles, but they used to be bacteria. As they transitioned from endosymbionts to organelles, they became more and more integrated into the biochemistry and cell biology of their hosts. Work over the last 15 years has shown that other symbioses show striking similarities to mitochondria and chloroplasts. In particular, many sap-feeding insects house intracellular bacteria that have genomes that overlap mitochondria and chloroplasts in terms of size and coding capacity. The massive levels of gene loss in some of these bacteria suggest that they, too, are becoming highly integrated with their host cells. Understanding these bacteria will require inspiration from eukaryotic cell biology, because a traditional microbiological framework is insufficient for understanding how they work.

  16. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size......The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds...

  17. METABOLIC MODELLING IN THE DEVELOPMENT OF CELL FACTORIES BY SYNTHETIC BIOLOGY

    Directory of Open Access Journals (Sweden)

    Paula Jouhten

    2012-10-01

    Full Text Available Cell factories are commonly microbial organisms utilized for bioconversion of renewable resources to bulk or high value chemicals. Introduction of novel production pathways in chassis strains is the core of the development of cell factories by synthetic biology. Synthetic biology aims to create novel biological functions and systems not found in nature by combining biology with engineering. The workflow of the development of novel cell factories with synthetic biology is ideally linear which will be attainable with the quantitative engineering approach, high-quality predictive models, and libraries of well-characterized parts. Different types of metabolic models, mathematical representations of metabolism and its components, enzymes and metabolites, are useful in particular phases of the synthetic biology workflow. In this minireview, the role of metabolic modelling in synthetic biology will be discussed with a review of current status of compatible methods and models for the in silico design and quantitative evaluation of a cell factory.

  18. 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

  19. [Novel concepts in biology of diffuse endocrine system: results and future investigations].

    Science.gov (United States)

    Iaglov, V V; Iaglova, N V

    2012-01-01

    Diffuse endocrine system is a largest part of endocrine system of vertebrates. Recend findings showed that DES-cells are not neuroectodermal but have ectodermal, mesodermal, and entodermal ontogeny. The article reviews novel concept of diffuse endocrine system anatomy and physiology, functional role of DES hormones and poorly investigated aspects like DES-cell morphology, hormones secretion in normal and pathologic conditions. Further research of diffuse endocrine system has a great significance for biochemistry, morphology, and clinical medicine.

  20. [Expression of angiogenin in COS-7 cells and analysis of its biological activity].

    Science.gov (United States)

    Wang, Yuan-Yuan; Zou, Min-Jig; Cai, Xin; Liu, Shen; Wang, Jin-Feng; Xu, Tao; Wang, Jia-Xi; Su, Hang; Xu, Dong-Gan

    2008-06-01

    This study was purposed to investigate the angiogenin (ANG) expression in COS-7 cells and its biological activity. The gene of angiogenin was obtained from mononuclear cells of peripheral blood by using RT-PCR and inserted into eukaryotic expression vector of pcDNA3.1. After being transfected into COS-7 cells, the recombinant ANG was identified by Western blot assay. The function of promoting proliferation of ANG to ECV304 cells was detected by MTT method, and its activity of vascularization was analyzed by chick embryo chorioallantois treated by the culture supernatant after transfection with pcDNA3.1-ang. The result showed that recombinant ANG was expressed in COS-7 cells after transfection for 24 to 36 hours. It could specifically react with monoclonal antibody against ANG. The recombinant ANG could obviously promote the proliferation of ECV304 cells. In contrast with the control group, the culture supernatant of pcDNA3.1-ang transfected group could stimulate the angiogenesis in embryo chorioallantois. It is concluded that the ang transiently expresses in COS-7 cells, and its expression product obviously stimulates the cell proliferation and angiogenesis.