2,866 results on '"Tibell, A"'
Search Results
352. Taxonomy of Calicium victorianum (F. Wilson) Tibell (Caliciaceae, Lecanorales), a lichenized ascomycete new to Europe
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Brian Spooner, Tetsuo Kokubun, Leif Tibell, and Begoña Aguirre-Hudson
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Caliciaceae ,Lecanorales ,Phylogenetic tree ,biology ,Botany ,Calicium victorianum ,Taxonomy (biology) ,Calicium ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Abstract
The morphological features and chemical compounds found in the first European collection of Calicium victorianum are compared with type material from Australia of C. piperatum F. Wilson. The phylogenetic relationships of the species are discussed by comparing its nuclear rDNA ITS1-5.8S-ITS2 with that of other species of Calicium.
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- 2007
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353. Islet Surface Heparinization Prevents the Instant Blood-Mediated Inflammatory Reaction in Islet Transplantation
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Marie Felldin, Rolf Larsson, Bo Nilsson, Ragnar Källén, Olle Korsgren, Gunnar Tufveson, Annika Tibell, Aksel Foss, Sanja Cabric, Javier Sanchez, Torbjörn Lundgren, and Kaija Salmela
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endocrine system ,medicine.medical_specialty ,endocrine system diseases ,Swine ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Transplantation, Heterologous ,Islets of Langerhans Transplantation ,Inflammation ,02 engineering and technology ,Models, Biological ,Transplantation, Autologous ,ABO Blood-Group System ,Tissue Culture Techniques ,Islets of Langerhans ,Mice ,03 medical and health sciences ,Tissue factor ,Diabetes mellitus ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Humans ,030304 developmental biology ,0303 health sciences ,geography ,geography.geographical_feature_category ,Heparin ,business.industry ,Insulin ,Pancreatic islets ,Graft Survival ,Endothelial Cells ,021001 nanoscience & nanotechnology ,Islet ,medicine.disease ,3. Good health ,Perfusion ,Transplantation ,Endocrinology ,medicine.anatomical_structure ,medicine.symptom ,0210 nano-technology ,business ,medicine.drug - Abstract
OBJECTIVE—In clinical islet transplantation, the instant blood-mediated inflammatory reaction (IBMIR) is a major factor contributing to the poor initial engraftment of the islets. This reaction is triggered by tissue factor and monocyte chemoattractant protein (MCP)-1, expressed by the transplanted pancreatic islets when the islets come in contact with blood in the portal vein. All currently identified systemic inhibitors of the IBMIR are associated with a significantly increased risk of bleeding or other side effects. To avoid systemic treatment, the aim of the present study was to render the islet graft blood biocompatible by applying a continuous heparin coating to the islet surface. RESEARCH DESIGN AND METHODS—A biotin/avidin technique was used to conjugate preformed heparin complexes to the surface of pancreatic islets. This endothelial-like coating was achieved by conjugating barely 40 IU heparin per full-size clinical islet transplant. RESULTS—Both in an in vitro loop model and in an allogeneic porcine model of clinical islet transplantation, this heparin coating provided protection against the IBMIR. Culturing heparinized islets for 24 h did not affect insulin release after glucose challenge, and heparin-coated islets cured diabetic mice in a manner similar to untreated islets. CONCLUSIONS—This novel pretreatment procedure prevents intraportal thrombosis and efficiently inhibits the IBMIR without increasing the bleeding risk and, unlike other pretreatment procedures (e.g., gene therapy), without inducing acute or chronic toxicity in the islets.
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- 2007
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354. Prevention of Transnational Transplant-Related Crimes-What More Can be Done?
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Beatriz Domínguez-Gil, Farhat Moazam, Monir Moniruzzaman, Marta López-Fraga, Kristof Van Assche, Annika Tibell, Sheelagh McGuinness, Gabriel M. Danovitch, Debra Budiani-Saberi, Mohamed A. Bakr, Francis L. Delmonico, Dominique Martin, Elmi Muller, Igor Codreanu, Saraladevi Naicker, Alexander Morgan Capron, Jacob Lavee, and Mona Al Rukhaimi
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Health Knowledge, Attitudes, Practice ,Attitude of Health Personnel ,International Cooperation ,Medical tourism ,Declaration ,Organ Trafficking ,030230 surgery ,Truth Disclosure ,Criminal investigation ,03 medical and health sciences ,0302 clinical medicine ,Medical Tourism ,Political science ,Extraterritorial jurisdiction ,Humans ,Registries ,Enforcement ,Physician's Role ,Policy Making ,Health policy ,Transplantation ,Health Policy ,Malpractice ,Organ Transplantation ,Tissue Donors ,Law ,030211 gastroenterology & hepatology ,Professional Misconduct - Abstract
Background. Many nations are able to prosecute transplant-related crimes committed in their territory, but transplant recipients, organ sellers and brokers, and transplant professionals may escape prosecution by engaging in these practices in foreign locations where they judge the risk of criminal investigation and prosecution to be remote. Methods.The Declaration of Istanbul Custodian Group convened an international working group to evaluate the possible role of extraterritorial jurisdiction in strengtheningtheenforcementof existinglawsgoverningtransplant-relatedcrimesacrossnationalboundaries.Potentialpracticalandethical concerns about the use of extraterritorial jurisdiction were examined, and possible responses were explored. Results. Extraterritorialjurisdictionisa legitimate tooltocombattransplant-relatedcrimes. Further,developmentofaglobalregistryoftransnationaltransplantactivitiesinconjunctionwitha standardizedinternationalreferralsystemforlegitimate travelfortransplantationis proposed as a mechanism to support enforcement of national and international legal tools. Conclusions. States are encouraged to include provisions on extraterritorial jurisdiction in their laws on transplant-related crimes and to collaborate with professionals and international authorities in the development of a global registry of transnational transplant activities. These actions would assist in the identification and evaluation of illicit activities and provide information that would help in developing strategies to deter and prevent them. (Transplantation 2015;00: 00–00)
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- 2015
355. Implementation of China’s new policies on organ procurement: an important but challenging step forward
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Martin, Dominique E. and Tibell, Annika
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Commentary - Published
- 2015
356. A phylogeny for the plant pathogen Piptoporellus baudoniiusing a multigene data set
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Tibuhwa, Donatha D., Hussein, Juma M., Ryvarden, Leif, Sijaona, Mark E. R., and Tibell, Sanja
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ABSTRACTPiptoporellus baudoniiis proposed as a new combination for Laetiporus baudoniiin the Polyporales (Basidiomycota) based on morphological and molecular features. This parasitic macrofungus attacks cashew trees, Eucalyptus, cassava, Tectona, and some indigenous trees in southern regions of Tanzania and poses a serious threat to agroforestry and livelihood conditions in the area. Phylogenetic trees were produced from partial sequences of three rDNA gene regions and a portion of translation elongation factor 1-alpha (TEF1) gene of Laetiporus baudoniifor comparisons with samples from the antrodia clade. Our results reveal a strongly supported group of L. baudoniiwith Piptoporellusin Fomitopsidaceae. Piptoporellus baudoniishares many morphological features with other members of Piptoporellusbut differs from them in having broadly ellipsoid or rarely ovoid basidiospores. Both morphological and phylogenetic evidence justify the placement of L. baudoniiin Piptoporellustogether with the three other known species in the genus.
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- 2020
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357. Eurotiomycetes: Eurotiomycetidae and Chaetothyriomycetidae
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François Lutzoni, Conrad L. Schoch, Cécile Gueidan, Frank Kauff, Emily Fraker, Wendy A. Untereiner, David M. Geiser, Jolanta Miadlikowska, André Aptroot, Leif Tibell, and Valérie Hofstetter
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0106 biological sciences ,0301 basic medicine ,Physiology ,Molecular Sequence Data ,Sequence Homology ,Eurotiales ,DNA, Ribosomal ,010603 evolutionary biology ,01 natural sciences ,03 medical and health sciences ,Peptide Elongation Factor 1 ,Ascomycota ,RNA, Ribosomal, 28S ,Botany ,RNA, Ribosomal, 18S ,Genetics ,Cluster Analysis ,DNA, Fungal ,Molecular Biology ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Chaetothyriales ,Ecology ,biology ,Chaetothyriomycetidae ,Fungal genetics ,Sequence Analysis, DNA ,Onygenales ,Sordariomycetes ,Cell Biology ,General Medicine ,030108 mycology & parasitology ,biology.organism_classification ,Eurotiomycetes ,Evolutionary biology ,RNA Polymerase II ,Pezizomycotina - Abstract
The class Eurotiomycetes (Ascomycota, Pezizomycotina) is a monophyletic group comprising two major clades of very different ascomycetous fungi: (i) the subclass Eurotiomycetidae, a clade that contains most of the fungi previously recognized as Plectomycetes because of their mostly enclosed ascomata and prototunicate asci; and (ii) the subclass Chaetothyriomycetidae, a group of fungi that produce ascomata with an opening reminiscent of those produced by Dothideomycetes or Sordariomycetes. In this paper we use phylogenetic analyses based on data available from the Assembling the Fungal Tree of Life project (AFTOL), in addition to sequences in GenBank, to outline this important group of fungi. The Eurotiomycetidae include producers of toxic and useful secondary metabolites, fermentation agents used to make food products and enzymes, xerophiles and psychrophiles, and the important genetics model Aspergillus nidulans. The Chaetothyriomycetidae include the common black yeast fungi, some of which are pathogens of humans and animals, as well as some primarily lichenized groups newly found to be phylogenetically associated with this group. The recently proposed order Mycocaliciales shows a sister relationship with Eurotiomycetes. The great majority of human pathogenic Pezizomycotina are Eurotiomycetes, particularly in Eurotiales, Onygenales and Chaetothyriales. Due to their broad importance in basic research, industry and public health, several genome projects have focused on species in Onygenales and Eurotiales.
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- 2006
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358. Changing Donation Pattern in Central Sweden
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Croon, A.C., Wahlberg, J., Andréasson, C., Bergström, C., Björklund, E., Jynge, Ö., Wilczek, H., and Tibell, A.
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- 2006
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359. Aspicilia goettweigensis (Megasporaceae, lichenized Ascomycetes) – a poorly known and overlooked species in Europe and Russia
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Paukov, Alexander, Nordin, Anders, Tibell, Leif, Frolov, Ivan, Vondrak, Jan, Paukov, Alexander, Nordin, Anders, Tibell, Leif, Frolov, Ivan, and Vondrak, Jan
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Aspicilia goettweigensis is a poorly known species from xerothermic siliceous rocks in Europe. It is considered to be common in the Czech Republic and it is new to Hungary and Russia. The main diagnostic character is formation of cracked, popcorn-like, areoles in the central parts of the thalli. Analysis of nrITS sequences revealed its close relationship to Aspicilia subdepressa and A. volcanica. TLC revealed stictic acid in analysed A. goettweigensis samples. A key to non-lobate Aspicilia with stictic acid known from Europe is provided.
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- 2017
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360. Sporodictyon
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Tibell, Sanja and Tibell, Sanja
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- 2017
361. Henrica
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Tibell, Sanja and Tibell, Sanja
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- 2017
362. A conceptual characterization of online videos explaining natural selection
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Bohlin, Gustav, Göransson, Andreas C., Höst, Gunnar, Tibell, Lena, Bohlin, Gustav, Göransson, Andreas C., Höst, Gunnar, and Tibell, Lena
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Educational videos on the Internet comprise a vast and highly diverse source of information. Online search engines facilitate access to numerous videos claiming to explain natural selection, but little is known about the degree to which the video content match key evolutionary content identified as important in evolution education research. In this study, we therefore analyzed the content of 60 videos accessed through the Internet, using a criteria catalog with 38 operationalized variables derived from research literature. The variables were sorted into four categories: (a) key concepts (e.g. limited resources and inherited variation), (b) threshold concepts (abstract concepts with a transforming and integrative function), (c) misconceptions (e.g. that evolution is driven by need), and (d) organismal context (e.g. animal or plant). The results indicate that some concepts are frequently communicated, and certain taxa are commonly used to illustrate concepts, while others are seldom included. In addition, evolutionary phenomena at small temporal and spatial scales, such as subcellular processes, are rarely covered. Rather, the focus is on population-level events over time scales spanning years or longer. This is consistent with an observed lack of explanations regarding how randomly occurring mutations provide the basis for variation (and thus natural selection). The findings imply, among other things, that some components of natural selection warrant far more attention in biology teaching and science education research., EvoVis
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- 2017
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363. Biological Principles and Threshold Concepts for Understanding Natural Selection Implications for Developing Visualizations as a Pedagogic Tool
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Tibell, Lena, Harms, Ute, Tibell, Lena, and Harms, Ute
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Modern evolutionary theory is both a central theory and an integrative framework of the life sciences. This is reflected in the common references to evolution in modern science education curricula and contexts. In fact, evolution is a core idea that is supposed to support biology learning by facilitating the organization of relevant knowledge. In addition, evolution can function as a pivotal link between concepts and highlight similarities in the complexity of biological concepts. However, empirical studies in many countries have for decades identified deficiencies in students scientific understanding of evolution mainly focusing on natural selection. Clearly, there are major obstacles to learning natural selection, and we argue that to overcome them, it is essential to address explicitly the general abstract concepts that underlie the biological processes, e.g., randomness or probability. Hence, we propose a two-dimensional framework for analyzing and structuring teaching of natural selection. The first-purely biological-dimension embraces the three main principles variation, heredity, and selection structured in nine key concepts that form the core idea of natural selection. The second dimension encompasses four so-called thresholds, i.e., general abstract and/or non-perceptual concepts: randomness, probability, spatial scales, and temporal scales. We claim that both of these dimensions must be continuously considered, in tandem, when teaching evolution in order to allow development of a meaningful understanding of the process. Further, we suggest that making the thresholds tangible with the aid of appropriate kinds of visualizations will facilitate grasping of the threshold concepts, and thus, help learners to overcome the difficulties in understanding the central theory of life., Funding Agencies|Swedish Research Council [VR 2012:5344]
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- 2017
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364. Ökade möjligheter till konkurrensrättsligt skadestånd? : En utredning av konkurrensskadelagen och dess verkan på rättsläget avseende skadeståndstalan vid konkurrensrättslig överträdelse
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Lundqvist, Frida, Tibell, Emma, Lundqvist, Frida, and Tibell, Emma
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Den 27 december 2016 trädde konkurrensskadelagen i kraft. Lagen är ett resultat av Sveriges implementering av Europaparlamentets och Rådets direktiv 2014/104/EU. Direktivet antogs till följd av att ovanligheten att driva skadeståndstalan vid överträdelse av konkurrensreglerna är något som uppmärksammats och diskuterats på EU-nivå under en längre tid. Direktivets syfte är att harmonisera medlemsstaternas reglering avseende konkurrensrättsligt skadestånd. Det har utfärdats för att alla som lidit skada av konkurrensrättsliga överträdelser, exempelvis en kartell, effektivt ska kunna utöva sin rätt att kräva ersättning. I Sverige har det under lång tid funnits möjlighet att driva skadeståndstalan på konkurrensrättslig grund. Det har emellertid varit en ovanlig företeelse att utnyttja denna rätt, varför effektiviteten kring våra nationella regler går att ifrågasätta. Uppsatsen fokuserar på att redogöra för den nya konkurrensskadelagens huvuddrag och analysera de sannolika positiva och negativa följder lagen kan tänkas medföra för skadelidande part i skadeståndsprocessen. Vi kan konstatera att införandet av konkurrensskadelagen skapar goda förutsättningar för skadelidande och kan väntas medföra ökade incitament att driva skadeståndstalan vid konkurrensrättsliga överträdelser. Frågan är om det är nog för att medföra en följd i form av ett ökat antal processer på området. Oavsett anser vi att införandet av konkurrensskadelagen är ett steg i rätt riktning för att uppnå målet om ett effektivt system för den som lidit skada av en konkurrensrättslig överträdelse.
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- 2017
365. Evolving germs – Introducing novice pupils to the evolution of bacterial resistance to antibiotics
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Bohlin, Gustav, Göransson, Andreas C., Höst, Gunnar E., Tibell, Lena A. E., Bohlin, Gustav, Göransson, Andreas C., Höst, Gunnar E., and Tibell, Lena A. E.
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There is a dual relationship between antibiotic resistance and biological evolution. Antibiotic resistance is typically used as a motivation for why we need an efficient evolution education given that evolutionary reasoning improves our understanding of causes and suggested countermeasures. On the other hand, antibiotic resistance has also been suggested as a useful context in which evolution can be taught, based primarily but not solely on the quick generation times of bacteria. In the present study, we explore the potential benefits with using antibiotic resistance as an example when introducing evolution to novice pupils (aged 13-14). We created a series of animations that pupils interacted with in groups of 3-5 (total n=32). Data was collected on both individual (pre-posttest) and group (collaborative group questions) level. In addition, the exercise was video-taped and the full transcripts were analyzed inductively. The results show that a majority of the pupils succeeded in applying basic evolutionary reasoning to make predictions on antibiotic resistance during and after the exercise, suggesting that this may be a successful approach. Cautions to be aware of include pupils’ use of teleological and antropomorphic reasoning, especially in discussions on submicroscopical phenomena such as genetic processes. Implications for teaching include both lessons from the design of animations as well as the identification of common misunderstandings. The analysis also identifies and points toward several possible future research endeavours., EvoVis
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- 2017
366. Moving between scales – zooming in time
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Stenlund, Jörgen, Tibell, Lena, Stenlund, Jörgen, and Tibell, Lena
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Teaching and learning evolution is tainted by challenges, e.g. combining time scales of a huge difference. The aim of this exploratory study is to understand how different visual representations of time affect the perception of temporal aspects in an evolutionary process. The research questions addressed in this study are: How do different ways of representing time affect the way students perceive of events at specific times, order of events, time intervals and the ability to relate time intervals? Do different time representations give rise to different responses concerning interactivity? In this study, a visualisation designed as a map superimposed by animated areas representing the appearance, dispersal and disappearance of different species, or groups of species, in hominin evolution was used. Three groups of participants were compared, each using variants of the visualisation, differing only in the way time was represented. The differences concerned whether the rate of time was constant or variable and whether there was one single timeline, or if several timelines with different scales were displayed. How the differences affected time perception, and interactions with the visualisation were analysed. Data were collected via a web questionnaire and screen-recordings complemented with quantitative data of the interactions on the computer. The difference between the groups performance were most pronounced concerning questions about events and intervals close to present time in the visualisation, especially estimations of time intervals and relating time intervals where the group using a visualisation with only one timeline performed poorest. The group which generally performed best used an animation featuring seve-ral timelines with different scales as well as a variable time rate. The most time-consuming questions involved estimations of time intervals and comparisons of time intervals. The group using the visualisation with a single timeline had the lowest frequ
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- 2017
367. Additional species in Tetramelas
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Anders Nordin and Leif Tibell
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biology ,Evolutionary biology ,Ecology ,Phylogenetics ,Buellia ,Tetramelas ,Buellia pulverulenta ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Tetramelas phaeophysciae ,Maximum parsimony - Abstract
Tetramelas phaeophysciae, a new obligately lichenicolous species occurring in Scandinavia, Iceland and Greenland, is described, and the closely related Buellia pulverulenta, together with B. triphragmioides, are transferred to Tetramelas. Phylogenetic reconstructions based on sequence data from nITS1-5.8S-ITS2 rDNA, using Bayesian inference and parsimony analyses, support the segregation of the new species from B. pulverulenta as well as the segregation of Tetramelas and Diplotomma from Buellia s. str.
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- 2005
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368. Tissue Factor Produced by the Endocrine Cells of the Islets of Langerhans Is Associated With a Negative Outcome of Clinical Islet Transplantation
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Graciela Elgue, Helena Johansson, Lisa Moberg, Kristina Nilsson Ekdahl, Annika Tibell, Torbjörn Lundgren, Aksel Foss, Bo Nilsson, Kaija Salmela, C Berne, Ragnar Källén, Agneta Lukinius, Marie Felldin, Gunnar Tufveson, and Olle Korsgren
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Adult ,Male ,medicine.medical_specialty ,Time Factors ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Antithrombin III ,Islets of Langerhans Transplantation ,Enteroendocrine cell ,Factor VIIa ,Biology ,Glucagon ,Thromboplastin ,Islets of Langerhans ,Tissue factor ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Inflammation ,geography ,geography.geographical_feature_category ,Insulin ,Middle Aged ,Islet ,Immunohistochemistry ,In vitro ,Transplantation ,Alternative Splicing ,Endocrinology ,Female ,Peptide Hydrolases - Abstract
There are strong indications that only a small fraction of grafts successfully engraft in clinical islet transplantation. One explanation may be the instant blood-mediated inflammatory reaction (IBMIR) elicited by tissue factor, which is produced by the endocrine cells. In the present study, we show that islets intended for islet transplantation produce tissue factor in both the transmembrane and the alternatively spliced form and that the membrane-bound form is released as microparticles often associated with both insulin and glucagon granules. A low–molecular mass factor VIIa (FVIIa) inhibitor that indirectly blocks both forms of tissue factor was shown in vitro to be a promising drug to eliminate the IBMIR. Thrombin-antithrombin complex (TAT) and FVIIa-antithrombin complex (FVIIa-AT) were measured in nine patients who together received 20 infusions of isolated human islets. Both the TAT and FVIIa-AT complexes increased rapidly within 15–60 min after infusion. When the initial TAT and FVIIa-AT levels were plotted against the increase in C-peptide concentration after 7 days, patients with an initially strong IBMIR showed no significant increase in insulin synthesis after 7 days. In conclusion, tissue factor present in both the islets and the culture medium and elicits IBMIR, which affects the function of the transplanted islets.
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- 2005
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369. Current Status of Clinical Islet Transplantation
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Gunnar Tufveson, Ragnar Källén, Aksel Foss, C Berne, Torgny Lundgren, Annika Tibell, Bo Nilsson, Marie Felldin, Olle Korsgren, and Kaija Salmela
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endocrine system ,Transplantation ,Type 1 diabetes ,medicine.medical_specialty ,geography ,geography.geographical_feature_category ,endocrine system diseases ,business.industry ,medicine.disease ,Islet ,Surgery ,Tolerance induction ,Treatment modality ,Diabetes mellitus ,medicine ,Intensive care medicine ,business - Abstract
Islet transplantation is currently being explored as a treatment for patients with type 1 diabetes. At present, the number of patients becoming insulin-independent is rapidly increasing world-wide applying the transplantation protocol originally described by the group in Edmonton. A hallmark in this procedure is repeated infusions of islets obtained from 2 to 4 donors until normoglycemia is achieved. In order to establish islet transplantation as a widely accepted treatment modality, and make tolerance induction regimes applicable, it is essential that the donor:recipient ratio is brought down to 1:1. A conceivable strategy to achieve this goal in clinical islet transplantation is discussed.
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- 2005
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370. Biological activity of pig islet-cell reactive IgG antibodies in xenotransplanted diabetic patients
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Erna Möller, Annika Tibell, Birger Christensson, Ellinor Lindeborg, and Makiko Kumagai-Braesch
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endocrine system ,Time Factors ,Swine ,Xenotransplantation ,medicine.medical_treatment ,Transplantation, Heterologous ,Immunology ,Population ,Islets of Langerhans Transplantation ,Antibodies, Heterophile ,Immunoglobulin G ,Epitope ,Antigen ,medicine ,Animals ,Humans ,education ,Autoantibodies ,Antibody-dependent cell-mediated cytotoxicity ,Transplantation ,education.field_of_study ,geography ,geography.geographical_feature_category ,biology ,Graft Survival ,Islet ,Molecular biology ,Diabetes Mellitus, Type 1 ,biology.protein ,Antibody - Abstract
Background: The IgG antibody response in type I diabetic patients, transplanted with fetal pig islet-like cell-clusters, was investigated using purified immunoglobulin G (IgG) fractions from sera collected 7 to 9 yr after transplantation. From our earlier studies, we knew that the immunological specificities of xenoreactive IgG1 and IgG2 antibodies are different, and that IgG1 antibodies, in contrast to the IgG2 population, are mainly directed against non-Galα1,3Gal epitopes. In this study our goal was to establish whether xenoreactive IgG1 and IgG2 antibodies react with pig islet cells and, if so, to identify the target cell type, the biological function as well as the specificity of such antibodies for islet cell antigens. Sera from xenotransplanted patients were compared with those of patients with diabetes, selected for high titres of islet-cell specific autoantibodies. Methods: IgG antibody fractions from patient sera were purified on a protein G column. Surface expression of target antigens was studied using flow cytometry as well as immunofluorescence microscopy. The biological function of islet-cell reactive sera was tested using antibody dependent cellular cytotoxicity with both xenogeneic adult pig islet cells and allogeneic human islet cells as targets. Antibody specificity was assessed using 2D Western blots with both fetal and adult pig islet as well as human islet cell antigenic preparations. Results: Some of the diabetic patients, who have been transplanted with xenogeneic fetal pig islet cells, continue to produce xenospecific IgG1 and IgG2 antibodies for 7 to 9 yr post-transplantation. A separate analysis of IgG1 and IgG2 antibodies showed that IgG1 antibodies react with pig islet β cells, whereas IgG2 antibodies mainly react with non-endocrine pig cells. Such antibodies are xenospecific, as they were found to mediate antibody-dependent cellular cytotoxicity of adult pig, but not human islet target cells. The reverse was true for antibodies from non-transplanted diabetic patients with high titres of autoantibodies against β cells. Fluorescence analysis as well as 2D gel Western blots revealed that the reactivity was variable between patient samples, indicating that target antigens for non-Galα1,3Gal-specific antibodies are heterogeneous. Conclusion: Thus, xenotransplantation of diabetic patients induces islet-β cell reactive xenospecific IgG1 antibodies, which are biologically active and can mediate antibody-dependent cellular cytotoxicity of pig islet cells.
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- 2004
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371. Two new species of Atla (Verrucariaceae)
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Tibell, Sanja, primary and Tibell, Leif, additional
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- 2015
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372. Nicotinamide inhibits tissue factor expression in isolated human pancreatic islets: implications for clinical islet transplantation1
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Gunnar Tufveson, Christian Berne, Lisa Moberg, Bo Nilsson, Ragnar Källén, Annika Olsson, Aksel Foss, Marie Felldin, K. Salmela, Annika Tibell, and Olle Korsgren
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endocrine system ,medicine.medical_specialty ,endocrine system diseases ,030209 endocrinology & metabolism ,Biology ,03 medical and health sciences ,chemistry.chemical_compound ,Tissue factor ,0302 clinical medicine ,Internal medicine ,Gene expression ,medicine ,030304 developmental biology ,0303 health sciences ,Transplantation ,geography ,geography.geographical_feature_category ,Nicotinamide ,Pancreatic islets ,Islet ,In vitro ,3. Good health ,B vitamins ,Endocrinology ,medicine.anatomical_structure ,chemistry - Abstract
Nicotinamide inhibits tissue factor expression in isolated human pancreatic islets : Implications for clinical islet transplantation
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- 2003
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373. Effect of plasma exchange in combination with deoxyspergualin on the survival of guinea-pig hearts in macrophage-depleted C6-deficient rats
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Guosheng Wu, Olle Korsgren, Nico van Rooijen, Shibo Sun, and Annika Tibell
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Transplantation ,biology ,business.industry ,Macrophage infiltration ,Xenotransplantation ,medicine.medical_treatment ,Immunology ,Antibody level ,Guinea pig ,Andrology ,Untreated control ,medicine ,biology.protein ,Macrophage ,Immunohistochemistry ,Antibody ,business - Abstract
0.01 vs. controls). In untreated control rats, xenoreactive antibody (IgM, IgG) levels decreased immediately after PE, but their levels rapidly returned to normal. In rats treated with DSG or DSG + Lip-Cl2MDP, the IgM levels remained low during the observation period. Immunohistochemistry showed that macrophage infiltration into the graft was suppressed in Lip-Cl2MDP-treated groups at the time of rejection. Our results demonstrate that sustained suppression of antibody levels can be achieved by PE in combination with DSG and xenograft survival is further prolonged in macrophage-depleted C6- rats. These findings suggest that strategies targeting antibody and macrophages may be useful in prolonging xenograft survival.
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- 2003
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374. Benefiting from an open-ended experiment? A comparison of attitudes to, and outcomes of, an expository versus an open-inquiry version of the same experiment
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V. Christina B. Bergendahl, Lena A. E. Tibell, Bruno K. S. Lundberg, and C. Anders R. Berg
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Science instruction ,Secondary education ,Higher education ,business.industry ,media_common.quotation_subject ,Teaching method ,education ,University level ,Outcome (probability) ,Education ,Perception ,Mathematics education ,Laboratory experiment ,business ,Psychology ,media_common - Abstract
In this article we compare outcomes of an open-inquiry and an expository version of a chemistry laboratory experiment at university level for 190 students. The aim of the study was to investigate if these two versions would result in different outcomes depending on the students' attitudes towards learning. We used a questionnaire to find out their attitude position prior to the laboratory experiment. The outcome in the different versions of the experiment was evaluated by interviews, questions asked during the experiment and students self-evaluations. The main findings were that the open-inquiry version shows the most positive outcomes regarding learning outcome, preparation time, time spent in the laboratory and student perception of the experiment. The students with low attitude position needed more support to meet the challenge of an open-inquiry experiment, the support being a clearer explanation of the aims, and feedback from the instructor during the experiment.
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- 2003
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375. Spatial ability and the impact of visualization/animation on learning electrochemistry
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Eun-mi Yang, Thomas Andre, Thomas J. Greenbowe, and Lena Tibell
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Multimedia ,Spatial ability ,Teaching method ,Animation ,computer.software_genre ,Science education ,Education ,Visualization ,Test (assessment) ,Concept learning ,Mathematics education ,Psychology ,Visual learning ,computer - Abstract
This study assessed the impact of computer animations illustrating the chemical reactions that occurinside a battery on students enrolled in a college introductory chemistry course. Students received twolectures on electrochemistry dealing with the chemical principles of how batteries generate electricityutilizing either animations or still diagrams. Students also completed a chemical knowledge test, aFlashlight pre-test and two chemistry content exams before receiving the lectures. A spatial abilitytest was given after the lectures and the students were classified as high or low spatial ability accordingto their spatial ability scores. The chemical knowledge and Flashlight pre-test and two previous contentexams were used as covariates; the spatial ahility test Lvas used to assess any interaction of spatial abilityand treatment. The dependent measures were two parts (knowvledge and transfer) of a post-test onelectrochemical concepts (labelled Postl and Post2). On Postl, instructor-guided animations led to...
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- 2003
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376. Att lämna en bubbla : Identitetsprocesser hos unga avhoppare från frikyrkliga samfund
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Tibell, Anette and Hammarström, Daniel
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socialisation ,Identitet ,frikyrka - Abstract
Syftet med studien är att utveckla en socialpsykologisk förståelse för vad det innebär för individer att som uppvuxna i frikyrklig miljö i Sverige höra till en minoritet och vad ett avståndstagande från denna minoritet innebär i termer av identitetsprocesser. Studien genomfördes med kvalitativ metod och tio semistrukturerade intervjuer med avhoppare från ett frikyrkligt samfund. För att undersöka fenomenet har vi valt att använda analysmetoden Interpretative Phenomenological Analysis, vilken har väglett och präglat metodologiska överväganden och analys. Den teoretiska referensramen vilar på en socialkonstruktionistisk grund med teorier om socialisation, identitet och avvikande. Informanterna beskriver en relativt sluten uppväxtmiljö med en religiös världsåskådning och tydliga gränsdragningar mellan rätt och fel. I tonåren kom de i större utsträckning i kontakt med den sekulariserade omgivningen utanför och började ifrågasätta församlingens regler och värderingar. Därefter följde år av motstridiga tankar som sedan ledde fram till ett avhopp från frikyrkan. Av analysen kan vi dra slutsatsen att individer som växer upp i en frikyrklig miljö genomgår en socialisation som till viss del avviker från vad som betraktas som normen i samhället. De individer som väljer att lämna frikyrkan går genom förändringar i termer av identifieringsprocesser.
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- 2015
377. Common denominator of Cu/Zn superoxide dismutase mutants associated with amyotrophic lateral sclerosis: Decreased stability of the apo state
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Mikael Oliveberg, Lena A. E. Tibell, and Mikael J. Lindberg
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Protein Denaturation ,Protein Folding ,Phosphines ,Mutant ,medicine.disease_cause ,Superoxide dismutase ,chemistry.chemical_compound ,medicine ,Humans ,Amyotrophic lateral sclerosis ,Mutation ,Multidisciplinary ,biology ,Superoxide Dismutase ,Chemistry ,Superoxide ,Circular Dichroism ,Point mutation ,Amyotrophic Lateral Sclerosis ,Biological Sciences ,medicine.disease ,Biochemistry ,biology.protein ,TCEP ,Protein folding - Abstract
More than 100 point mutations of the superoxide scavenger Cu/Zn superoxide dismutase (SOD; EC ) have been associated with the neurodegenerative disease amyotrophic lateral sclerosis (ALS). However, these mutations are scattered throughout the protein and provide no clear functional or structural clues to the underlying disease mechanism. Therefore, we undertook to look for folding-related defects by comparing the unfolding behavior of five ALS-associated mutants with distinct structural characteristics: A4V at the interface between the N and C termini, C6F in the hydrophobic core, D90A at the protein surface, and G93A and G93C, which decrease backbone flexibility. With the exception of the disruptive replacements A4V and C6F, the mutations only marginally affect the stability of the native protein, yet all mutants share a pronounced destabilization of the metal-free apo state: the higher the stability loss, the lower the mean survival time for ALS patients carrying the mutation. Thus organism-level pathology may be directly related to the properties of the immature state of a protein rather than to those of the native species.
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- 2002
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378. Production of tissue factor by pancreatic islet cells as a trigger of detrimental thrombotic reactions in clinical islet transplantation
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Ø Østraat, Helena Johansson, Aksel Foss, Graciela Elgue, Olle Korsgren, Bo Nilsson, K Nilsson Ekdahl, Annika Tibell, Gunnar Tufveson, Agneta Lukinius, Ragnar Källén, C Berne, Lisa Moberg, and Kaija Salmela
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Adult ,Male ,endocrine system ,medicine.medical_specialty ,endocrine system diseases ,Edmonton protocol ,medicine.medical_treatment ,Islets of Langerhans Transplantation ,030230 surgery ,Thromboplastin ,Islets of Langerhans ,03 medical and health sciences ,Tissue factor ,Postoperative Complications ,0302 clinical medicine ,Internal medicine ,Humans ,Medicine ,030304 developmental biology ,0303 health sciences ,geography ,geography.geographical_feature_category ,Hematology ,business.industry ,Vascular disease ,Thrombosis ,General Medicine ,Middle Aged ,Islet ,medicine.disease ,Precipitin Tests ,humanities ,Blood Cell Count ,3. Good health ,Transplantation ,Diabetes Mellitus, Type 1 ,Endocrinology ,Cancer research ,Immunohistochemistry ,Female ,business - Abstract
Intraportal transplantation of pancreatic islets offers improved glycaemic control and insulin independence in type 1 diabetes mellitus, but intraportal thrombosis remains a possible complication. The thrombotic reaction may explain why graft loss occurs and islets from more than one donor are needed, since contact between human islets and ABO-compatible blood in vitro triggers a thrombotic reaction that damages the islets. We investigated the possible mechanism and treatment of such thrombotic reactions.Coagulation activation and islet damage were monitored in four patients undergoing clinical islet transplantation according to a modified Edmonton protocol. Expression of tissue factor (TF) in the islet preparations was investigated by immunohistochemistry, immunoprecipitation, electron microscopy, and RT-PCR. To assess TF activity in purified islets, human islets were mixed with non-anticoagulated ABO-compatible blood in tubing loops coated with heparin.Coagulation activation and subsequent release of insulin were found consistently after clinical islet transplantation, even in the absence of signs of intraportal thrombosis. The endocrine, but not the exocrine, cells of the pancreas were found to synthesise and secrete active TF. The clotting reaction triggered by pancreatic islets in vitro could be abrogated by blocking the active site of TF with specific antibodies or site-inactivated factor VIIa, a candidate drug for inhibition of TF activity in vivo.Blockade of TF represents a new therapeutic approach that might increase the success of islet transplantation in patients with type 1 diabetes, in terms of both the risk of intraportal thrombosis and the need for islets from more than one donor.
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- 2002
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379. Chaenotheca nitidula, A New Species of Calicioid Lichen from Northeastern North America
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Leif Tibell and Anna Koffman
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Stichococcus ,Chaenotheca nitidula ,Phylogenetic tree ,biology ,Ecology ,Botany ,Plant Science ,Chaenotheca gracilenta ,Lichen ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Thallus - Abstract
Chaenotheca nitidula is described as a new species from northeastern North America. It is characterized by long, shining stalks; rather small, spheric, non-pruinose capitul; immersed thallus; and its association with Stichococcus as photobiont. In a phylogenetic analysis based on rDNA ITS1–5.8S-ITS2 sequences, C. nitidula was most closely related to Chaenotheca gracilenta and C. gracillima. It occurs on wood of conifers in old woodlands and has so far been recorded from Maine and New Brunswick.
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- 2002
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380. Ribosomal DNA and β-tubulin data do not support the separation of the lichens Usnea florida and U. subfloridana as distinct species
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Leif Tibell, Martin Grube, Mats Wedin, Kristina Articus, and Jan-Eric Mattsson
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Usnea ,Phylogenetic tree ,biology ,Zoology ,Plant Science ,Spacer DNA ,biology.organism_classification ,Sexual reproduction ,stomatognathic diseases ,Botany ,Genetics ,Taxonomy (biology) ,Lichen ,Ribosomal DNA ,Ecology, Evolution, Behavior and Systematics ,Biotechnology ,Specific identification - Abstract
The lichens Usnea florida and U. subfloridana have since long been recognised as distinct species. They show many similarities in morphology, but have different reproductive strategies. Usnea flori ...
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- 2002
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381. Structural Requirements for High-Affinity Heparin Binding: Alanine Scanning Analysis of Charged Residues in the C-Terminal Domain of Human Extracellular Superoxide Dismutase
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Lena A. E. Tibell, Peter Stenlund, and Mikael J. Lindberg
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Arginine ,Protein Conformation ,Stereochemistry ,Lysine ,Biochemistry ,Chromatography, Affinity ,chemistry.chemical_compound ,Humans ,Alanine ,chemistry.chemical_classification ,Heparin ,Superoxide Dismutase ,Circular Dichroism ,Sepharose ,C-terminus ,Heparan sulfate ,Glutamic acid ,Surface Plasmon Resonance ,Alanine scanning ,Protein Structure, Tertiary ,Amino acid ,Amino Acid Substitution ,chemistry ,Mutagenesis ,Dimerization - Abstract
An essential property of human extracellular superoxide dismutase (hEC-SOD) is its affinity for heparin and heparan sulfate proteoglycans located on cell surfaces and in the connective tissue matrix. The C-terminal domain of hEC-SOD plays the major role in this interaction. This domain has an unusually high content of charged amino acids: six arginine, three lysine, and five glutamic acid residues. In this study, we used alanine scanning mutagenesis of charged amino acids in the C-terminal domain to elucidate the requirements for the heparin/heparan sulfate interaction. As a tool in this study, we used a fusion protein comprising the C-terminal domain of hEC-SOD fused to human carbonic anhydrase II (HCAII). The interaction studies were performed using the surface plasmon resonance technique and heparin-Sepharose chromatography. Replacement of the glutamic acid residues by alanine resulted, in all cases, in tighter binding. All alanine substitutions of basic amino acid residues, except one (R205A), reduced heparin affinity. The arginine and lysine residues in the cluster of basic amino acid residues (residues 210-215), the RK-cluster, are of critical importance for the binding to heparin, and arginine residues promote stronger interactions than lysine residues.
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- 2002
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382. Key Factors for Human Islet Isolation and Clinical Transplantation
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Goto, M., Johansson, U., Eich, T.M., Lundgrem, T., Engkvist, M., Felldin, M., Foss, A., Kallen, R., Salmela, K., Tibell, A., Tufveson, G., Nilsson, B., and Korsgren, O.
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- 2005
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383. Morphological variation, photobiont association and ITS phylogeny of Chaenotheca phaeocephala and C. subroscida (Coniocybaceae, lichenized ascomycetes)
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Leif Tibell and Andreas Beck
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Trebouxia ,Monophyly ,Coniocybaceae ,Chaenotheca phaeocephala ,Taxon ,biology ,Phylogenetics ,Zoology ,Morphology (biology) ,Plant Science ,biology.organism_classification ,Phenotype ,Ecology, Evolution, Behavior and Systematics - Abstract
Chaenotheca phaeocephala and C. subroscida have been characterized by differences in their morphology and ecology. They are, however, morphologically plastic and sometimes seem to intergrade. It has been suspected that the differences in morphology between these two taxa could possibly be phenotypic and caused by their occurrence in different habitats and/or by the association with different photobionts. To test if there is a genetic difference between the species ITS1–5.8S-ITS2 rDNA sequences of six specimens of the mycobiont of C. phaeocephala and five of C. subroscida were compared. Further the ITS1–5.8S-ITS2 rDNA sequences of the photobiont of one specimens of C. phaeocephala and six of C. subroscida were compared to each other and to other species of Trebouxia. The mycobiont sequences of both C. phaeocephala and C. subroscida were monophyletic, substantially different and the groups had strong supports. They also proved to be associated with different Trebouxia species, C. phaeocephala with T. arboricola and Chaenotheca subroscida with T. jamesii. The morphologically based concepts of C. phaeocephala and C. subroscida thus not merely represent phenotypic variation but also are associated with considerable genetic differences in the extremes of the ITS1–5.8S-ITS2 rDNA region.
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- 2001
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384. 21st Workshop of the Study Group on Artificial Insulin Delivery, Pancreas and Islet Transplantation (AIDPIT) of the European Association for the Study of Diabetes (EASD)
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Markus Idvall and Annika Tibell
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Research program ,Endocrinology, Diabetes and Metabolism ,Xenotransplantation ,medicine.medical_treatment ,Porcine islets ,education ,General Medicine ,University hospital ,Viewpoints ,Transplantation ,Endocrinology ,Orientation (mental) ,Internal Medicine ,medicine ,Engineering ethics ,Psychology ,Ethical analysis - Abstract
THROUGHOUT THE WORLD xenotransplantation researchers are confronted not only with medical and technological difficulties but also with cultural and ethical ambiguities. Within the research program “Treatment of Diabetes by Transplantation of Porcine Islets” at Karolinska Institute/Huddinge University Hospital in Stockholm, Sweden, an interview study has been performed concerning the cultural and ethical issues related to xenotransplantation research and development. The purpose of the study is to evaluate, from cultural and ethical viewpoints, the way in which the xenotransplantation approach is perceived among individuals who either professionally or by personal plight are engaged in the scientific development of treating diabetes by transplantation of porcine islets.
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- 2001
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385. Reaction cross sections of intermediate energy 3He-particles on targets from 9Be to 208Pb
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Gunnar Tibell, J. Peavy, A. Ingemarsson, S. V. Förtsch, G. J. Arendse, A. Auce, A. A. Cowley, B.R. Karlson, A. J. Cox, J. A. Stander, Mattias Lantz, G.F. Steyn, R. Johansson, and R. F. Carlson
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Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,medicine.anatomical_structure ,Intermediate energy ,medicine ,Atomic physics ,Wave function ,Nucleus ,Energy (signal processing) - Abstract
Reaction cross sections for 3 He-particles have been measured for 9 Be, 12 C, 16 O, 28 Si, 40 Ca, 58,60 Ni, 112,116,118,120,124 Sn, and 208 Pb at 96, 138 and 167 MeV. The results are compared with predictions from optical model calculations using phenomenological and global optical potentials. The behaviour of the wavefunctions and of the contributions to the reaction cross sections from different regions in the nucleus is investigated. Comparisons are also made with results for α -particles obtained in the same energy region.
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- 2001
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386. Cybebe gracilenta in an ITS/5.8S rDNA based phylogeny belongs to Chaenotheca (Coniocybaceae, lichenized Ascomycetes)
- Author
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Leif Tibell
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Coniocybaceae ,biology ,Evolutionary biology ,Phylogenetics ,Cybebe gracilenta ,biology.organism_classification ,Chaenotheca ,5 8s rdna ,Ecology, Evolution, Behavior and Systematics - Abstract
Cybebe was described as a monotypic genus in the Coniocybaceae distinguished from Chaenotheca by its unusual ascus ontogeny and its unpigmented spore wall. In a molecular phylogeny based on maximum parsimony analyses of their ITS1-5.8S-ITS2 rDXA sequences, specimens of Cybebe gracilenta formed a strongly supported group with Chaenotheca gracillima. Thisgroup in turn is also well supported as a part of Chaenotheca indicating that the features characteristic of Cybebe are indeed autapomorphic and that Cybebe gracilenta should be included in Chaenotheca.
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- 2001
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387. Suppression of T cells results in long-term survival of mouse heart xenografts in C6-deficient rats
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Nico van Rooijen, Guosheng Wu, Olle Korsgren, and Annika Tibell
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Nitric oxide synthase ,Transplantation ,biology ,business.industry ,Immunology ,Long term survival ,Cancer research ,biology.protein ,Medicine ,business ,Mouse Heart - Abstract
Suppression of T cells results in long-term survival of mouse heart xenograft in C6-deficient rats.
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- 2001
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388. Continued production of xenoimmune antibodies 6-8 years after clinical transplantation of fetal pig islet-like cell-clusters
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Makiko Kumagai-Braesch, E. Möller, Ellinor Lindeborg, and Annika Tibell
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Antibody-dependent cell-mediated cytotoxicity ,Transplantation ,Xenotransplantation ,medicine.medical_treatment ,Immunology ,Biology ,Peripheral blood mononuclear cell ,Epitope ,Immune system ,biology.protein ,medicine ,Cytotoxic T cell ,Antibody - Abstract
We have monitored the humoral immune responses of 10 type I diabetic patients, xenotransplanted with fetal porcine islet-like cell clusters for up to 8 years after xenotransplantation. We investigated the immunoglobulin subclass distribution as well as specificity differences of xenoreactive antibodies. Hemagglutintion tests, using pig erythrocytes, showed that some patients maintained higher titers of xenoreactive IgM antibodies during the entire follow up period, compared with pretransplant levels. In microcytotoxicity tests all but one patient tested showed higher than pretransplant levels of cytotoxic antibodies against pig peripheral blood mononuclear cells (PBMC) 6-8 years after transplantation. Levels of Gal alpha 1,3Gal specific antibodies, were also high. Antibody dependent cellular cytotoxicity (ADCC) activity against a Gal alpha 1,3Gal expressing human B cell line was detected in four patients while ADCC reactivity against adult pig islet cells was detected in only two patients, 6-8 years after transplantation. Immune sera collected 30 days and 1 year after transplantation showed positive staining of adult pig islet cells in fluoromicroscopy whereas sera from later time points did not. Western blot experiments showed that some patients had IgG1 antibodies reactive against epitopes on pig cells other than Gal alpha 1,3Gal, while xenoreactive IgM and IgG2 antibodies mainly reacted with Gal alpha 1,3Gal-containing epitopes as shown by absorption experiments. These results show that patients continue to produce higher than pretransplant levels of IgM and IgG2 xenospecific antibodies against Gal alpha 1,3Gal for extended time periods following xenotransplantation. Some patients also produce xenoreactive IgG1 antibodies directed against non-Gal alpha 1,3Gal epitopes.
- Published
- 2001
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389. Photobiont Association and Molecular Phylogeny of the Lichen GenusChaenotheca
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Leif Tibell
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Trebouxia ,Stichococcus ,Zoology ,Plant Science ,Biology ,biology.organism_classification ,Chaenotheca ,Genus ,Trentepohlia ,Molecular phylogenetics ,Botany ,Dictyochloropsis ,Lichen ,Ecology, Evolution, Behavior and Systematics - Abstract
Chaenotheca Th. Fr. is associated with four different genera of photobionts, Dictyochloropsis, Stichococcus, Trebouxia, and Trentepohlia. The species of Chaenotheca consistently harbor only one ...
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- 2001
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390. Adenovirus-mediated transfer of type IV collagen α5 chain cDNA into swine kidney in vivo: deposition of the protein into the glomerular basement membrane
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P Heikkilä, T Morita, Y Sado, E Pettersson, G Wu, Yoshifumi Ninomiya, Yunying Chen, K Tryggvason, and A Tibell
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medicine.medical_specialty ,Swine ,Renal glomerulus ,Genetic Vectors ,Kidney Glomerulus ,Nephritis, Hereditary ,Biology ,urologic and male genital diseases ,Basement Membrane ,Adenoviridae ,Cell Line ,Type IV collagen ,Internal medicine ,Genetics ,medicine ,Animals ,Humans ,RNA, Messenger ,Alport syndrome ,Molecular Biology ,Basement membrane ,urogenital system ,Glomerular basement membrane ,Genetic transfer ,Glomerulonephritis ,Genetic Therapy ,medicine.disease ,Molecular biology ,female genital diseases and pregnancy complications ,Perfusion ,Endocrinology ,medicine.anatomical_structure ,Models, Animal ,embryonic structures ,Molecular Medicine ,Collagen ,Alpha chain - Abstract
Gene therapy of Alport syndrome (hereditary nephritis) aims at the transfer of a corrected type IV collagen alpha chain gene into renal glomerular cells responsible for production of the glomerular basement membrane (GBM). A GBM network composed of type IV collagen molecules is abnormal in Alport syndrome which leads progressively to kidney failure. The most common X-linked form of the disease is caused by mutations in the gene for the alpha5(IV) chain, the alpha5 chain of type IV collagen. Full-length human alpha5(IV) cDNA was expressed in HT1080 cells with an adenovirus vector, and the recombinant alpha5(IV) chain was shown to assemble into heterotrimers consisting of alpha3(IV) and alpha4(IV) chains, utilizing a FLAG epitope in the recombinant alpha5(IV) chain. The results indicate that correction of the molecular defect in Alport syndrome is possible. Previously, we had developed an organ perfusion method for effective in vivo gene transfer into glomerular cells. In vivo perfusion of pig kidneys with the recombinant adenovirus resulted in expression of the alpha5(IV) chain in kidney glomeruli as shown by in situ hybridization and its deposition into the GBM was shown by immunohistochemistry. The results strongly suggest future possibilities for gene therapy of Alport syndrome.
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- 2001
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391. Intraspecific variation in Mycocalicium subtile (Mycocaliciaceae) elucidated by morphology and the sequences of the ITS1-5.8S-ITS2 region of rDNA
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Jose Maria Sanches-Puelles, Maria de Los Angeles Vinuesa, and Leif Tibell
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Species complex ,Synonym ,Zoology ,Plant Science ,Biology ,Monophyly ,Taxon ,Molecular phylogenetics ,Genetics ,Taxonomy (biology) ,Clade ,Ribosomal DNA ,Ecology, Evolution, Behavior and Systematics ,Biotechnology - Abstract
The aim of the present paper is to investigate if Mycocalicium subtile as presently circumscribed is a morphologically highly variable species, or in fact represents two or more cryptic species, and further to investigate the status of M. minutellum. The morphological variation of 19 specimens of Mycocalicium subtile from five continents was investigated and the ITS1-5.8S-ITS2 region of their rDNA sequenced. Sequences from closely related taxa, 4 specimens of M. albonigrum, 2 of Mycocalicium sp., and Chaenothecopsis nana were also included. For comparison the corresponding sequence of M. victoriae and C. pusilla were also determined. We used the sequence of Monascus purpureus as the outgroup for the analysis. The sequences were used for phylogenetic inference using parsimony and distance methods. All the specimens assigned to M. subtile with the exception of two, form a well-supported monophyletic group. Those two specimens represent a morphologically cryptic, but genetically distinctive taxon. The infraspecific clades of M. subtile in the molecular phylogeny did not correspond to geographical origin. Only a weak correlation with geographical origin was found in the morphological analysis. The molecular analysis supports the suggestion that Mycocalicium minutellum is a taxonomic synonym of M. subtile.
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- 2001
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392. The 10,11B(n,p)10,11Be reactions at En=96 MeV
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K. Lindh, H. Condé, Gunnar Tibell, Leif Nilsson, A. Ringbom, K. Elmgren, J. Rahm, T. Rönnqvist, Nils Olsson, Chr. Bargholtz, Olof Jönsson, Per-Ulf Renberg, P. Thörngren Engblom, K. Fransson, S.Y. van der Werf, Jan Blomgren, and P.-E. Tegnér
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Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Angular range ,Born approximation ,Atomic physics ,Nuclear Experiment ,Maxima ,Excitation ,Spectral line - Abstract
Double-differential cross sections of the 10,11 B(n, p) 10,11 Be reactions have been measured at 96 MeV in the angular range 0°–30° for excitation energies up to 35 MeV. The spectra have been decomposed into different multipolarities using sample angular distributions calculated within the distorted-wave Born approximation. From the identified Gamow–Teller strength, S β + values were obtained for 10 B and 11 B. At higher excitation energies, the spectra are dominated by L =1 strength in broad distributions with maxima around 22 and 12 MeV in 10 B and 11 B, respectively.
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- 2001
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393. Effect of Triple Costimulation Blockade on Islet Allograft Survival in Sensitized Mice
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Annika Tibell, T. Iwata, Makiko Kumagai-Braesch, Randa A. Hadi Diab, Jan Holgersson, Henrik Ekberg, and Matthias Corbascio
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Blood Glucose ,Graft Rejection ,Reoperation ,medicine.medical_treatment ,Intraperitoneal injection ,Islets of Langerhans Transplantation ,chemical and pharmacologic phenomena ,Pharmacology ,Article ,Diabetes Mellitus, Experimental ,Mice ,Antigen ,Antigens, CD ,medicine ,Animals ,Transplantation, Homologous ,Cytotoxic T cell ,CTLA-4 Antigen ,Mice, Inbred BALB C ,Transplantation ,geography ,geography.geographical_feature_category ,biology ,business.industry ,Graft Survival ,Streptozotocin ,Islet ,Blockade ,Mice, Inbred C57BL ,Immunoglobulin G ,Immunology ,biology.protein ,Surgery ,Antibody ,business ,medicine.drug - Abstract
Background. Islet allograft rejection in sensitized recipients is difficult to control by costimulation blockade using anti-CD154 and cytotoxic T-lymphocyte antigen-4 immunoglobulin (CTLA4Ig). Because leukocyte function antigen (LFA) 1 is highly expressed on memory T cells, adding an LFA-1 blockade may inhibit memory T-cell activities. We examined the effects on islet allograft survival of triple costimulation blockade in presensitized recipient mice. Methods. C57BL/6 mice were sensitized by transplantation under the kidney capsule or intraperitoneal injection of Balb/c islets. Four weeks after transplantation, sensitization was confirmed by flow-cytometric detection of alloreactive antibodies. Diabetes was induced by a single intravenous injection of streptozotocin. Recipients were transplanted with 200 Balb/c islets under the right kidney capsule. Graft function was assessed by daily blood glucose and body weight records. Transplanted animals were divided into 3 treatment groups: group 1, control antibody; group 2, anti-CD154 and CTLA-4 Ig double therapy; group 3, anti-CD154, CTLA4Ig, and anti LFA-1 triple therapy. Injections were administered every second day from day -2 to day 8. Results. Naive mice rejected islet allografts between days 7 and 29 (mean 16 +/- 6 d; n = 5), sensitized mice in group 1 between days 0 and 14 (mean 7 +/- 5 d; n = 8), in group 2 between days 4 and 16 (mean 8 +/- 4 d; n = 7), and in group 3 between days 4 and 26 (mean 11 +/- 7 d; n = 10). Conclusion. Triple costimulation blockade with anti-CD154, CTLA4Ig, and anti LFA-1 was not sufficient to improve islet allograft survival in sensitized recipients. (Less)
- Published
- 2010
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394. A synopsis of crustose calicioid lichens and fungi from mainland Africa and Madagascar
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Leif Tibell
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biology ,Ecology ,Plant Science ,biology.organism_classification ,humanities ,Parmeliaceae ,Botany ,Temperate climate ,Mainland ,Xanthoparmelia ,Calicium ,Crustose ,Lichen ,Ecology, Evolution, Behavior and Systematics - Abstract
A synopsis of 42 species is given. Thirteen of the species are tropical to warm temperate, seventeen of the species are antitropical and mainly occur in the mountainous areas. Calicium lutescens, C ...
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- 2000
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395. The (n,p) reaction and the Gamow–Teller unit cross section
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A. Ringbom, Somsak Dangtip, Olof Jönsson, Jan Blomgren, H. Condé, Gunnar Tibell, S.Y. van der Werf, Per-Ulf Renberg, K. Elmgren, Nils Olsson, Leif Nilsson, and J. Rahm
- Subjects
Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Light nucleus ,Cross section (physics) ,Angular range ,Range (particle radiation) ,Atomic physics ,Nuclear Experiment ,Beta decay ,Unit (ring theory) ,Excitation - Abstract
Double differential cross sections of the Be-9(n,p)Li-9 reaction have been measured at 96 MeV in the angular range 0 degrees-27 degrees up to about 20 MeV excitation energy. In addition, the C-12(n,p)B-12 reaction has been measured in the same angular and
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- 2000
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396. Clinical aspects and perspectives in islet xenotransplantation
- Author
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William Bennet, Carl G. Groth, Karl-Johan Rydgård, Olle Korsgren, Lars Wennberg, Torbjörn Lundgren, Susanne Lundin, Ellinor Lindeborg, and Annika Tibell
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Pathology ,medicine.medical_specialty ,Swine ,medicine.medical_treatment ,Xenotransplantation ,Transplantation, Heterologous ,Islets of Langerhans Transplantation ,Complement receptor ,Glucagon ,Biopsy ,medicine ,Animals ,Humans ,geography ,Fetus ,geography.geographical_feature_category ,Hepatology ,medicine.diagnostic_test ,business.industry ,Insulin ,Islet ,Kidney Transplantation ,Transplantation ,Diabetes Mellitus, Type 1 ,Surgery ,business ,Follow-Up Studies - Abstract
In 1990-1993, eight diabetic renal transplant patients had porcine fetal islets injected intraportally at Huddinge Hospital in Stockholm. Four of the patients had evidence of xenograft function reflected in the excretion of small amounts of porcine C-peptide. Two patients had the porcine fetal islets placed under the capsule of a simultaneously transplanted kidney. In one of these patients, a graft biopsy specimen taken 3 weeks after transplantation revealed morphologically intact epithelial cells staining positively for insulin and glucagon. The insulin production was in all instances insufficient to affect the patient's insulin requirements. All patients formed specific xenoantibodies (mostly anti-Gal); presumably, most of the xenoislets were destroyed by rejection. On follow-up studies carried out 6-8 years after xenotransplantation, most patients still had higher-than-pretransplant levels of xenoantibodies. There was no evidence of transmission of porcine endogeneous retroviruses to the patients. All patients expressed a positive attitude toward the use of animal tissue for treatment of disease, and none of the patients regretted participating in the trial. Cell transplantation is leading the way at present for clinical xenotransplantation. The finding that complement inhibition protects intraportally injected porcine islets from an injurious incompatibility reaction holds promise for future clinical application. A similar protective effect might be achievable with the use of islets from transgenic pigs expressing human complement receptors.
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- 2000
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397. Lack of antibody production against Hanganutziu-Deicher (H-D) antigens with N-glycolylneuraminic acid in patients with porcine exposure history
- Author
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Hiroshi Takagi, Takaaki Kobayashi, Lennart Rydberg, Kunio Morozumi, Itsuo Yokoyama, Carl G. Groth, Olle Korsgren, Akemi Suzuki, Annika Tibell, Michael E. Breimer, Mikiko Abe, Shuji Hayashi, Akimasa Nakao, and Haruo Matsuda
- Subjects
Antibody production ,Transplantation ,chemistry.chemical_compound ,chemistry ,Heterologous Antigens ,N-Glycolylneuraminic acid ,Immunology ,In patient ,Biology ,Exposure history ,Virology ,Molecular biology - Abstract
Lack of antibody production against Hanganutziu-Deicher (H-D) antigenswith N-glycolylneuraminic acid in patients with porcine exposure history[In Process Citation]
- Published
- 2000
- Full Text
- View/download PDF
398. New results for reaction cross sections of intermediate energy α-particles on targets from Be to Pb
- Author
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R. E. Warner, A. Auce, Dao T. Khoa, R. Johansson, R. F. Carlson, Gunnar Tibell, Per-Ulf Renberg, A. J. Cox, O. Sundberg, A. Ingemarsson, and Johan Nyberg
- Subjects
Physics ,Elastic scattering ,Nuclear and High Energy Physics ,Range (particle radiation) ,Intermediate energy ,Deuterium ,Isotope ,Nuclear cross section ,Atomic physics ,α particles ,Glauber - Abstract
Reaction cross sections for α -particles have been measured for 9 Be, 12 C, 16 O, 28 Si, 40 Ca, 58,60 Ni, 112,116,120,124 Sn, and 208 Pb at 117.2, 163.9 and 192.4 MeV and for the lighter nuclei also at 69.6 MeV. The results are compared with predictions from optical model calculations using phenomenological, global and double-folded optical potentials. Comparisons are also made with predictions using the Glauber model approach suggested by Bertsch, Brown and Sagawa.
- Published
- 2000
- Full Text
- View/download PDF
399. Pig islet xenograft rejection is markedly delayed in macrophage-depleted mice: a study in streptozotocin diabetic animals
- Author
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Guosheng Wu, Z Song, Olle Korsgren, J Zhang, N. van Rooijen, and Annika Tibell
- Subjects
endocrine system ,Transplantation ,medicine.medical_specialty ,geography ,geography.geographical_feature_category ,endocrine system diseases ,Xenotransplantation ,medicine.medical_treatment ,Immunology ,Biology ,Streptozotocin ,Islet ,Endocrinology ,Internal medicine ,medicine ,Macrophage ,medicine.drug - Abstract
Pig islet xenograft rejection is markedly delayed in macrophage-depletedmice: a study in streptozotocin diabetic animals [In Process Citation]
- Published
- 2000
- Full Text
- View/download PDF
400. An attempt at innovation in teacher training in Sweden
- Author
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Gunnar Tibell
- Subjects
Higher education ,business.industry ,media_common.quotation_subject ,General Physics and Astronomy ,Science teachers ,Biology ,Training (civil) ,Education ,ComputingMilieux_COMPUTERSANDEDUCATION ,Institution ,Mathematics education ,Chemistry (relationship) ,business ,media_common - Abstract
Much physics is now taught by teachers qualified in other sciences. It is surely worthwhile for such teachers to have some preparation in physcis, and to this end a new Swedish institution is attracting students with its courses on interdisciplinary thematic topics and courses `about' science.
- Published
- 2000
- Full Text
- View/download PDF
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