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Search Results: 1 - 10 of 1461 matches for " Kjell Petersen "
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Somatic Maintenance Resources in the Honeybee Worker Fat Body Are Distributed to Withstand the Most Life-Threatening Challenges at Each Life Stage
Siri-Christine Seehuus, Simon Taylor, Kjell Petersen, Randi M. Aamodt
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069870
Abstract: In a global transcriptome analysis of three natural and three manipulated honeybee worker phenotypes at different ages, we have investigated the distribution of investment in somatic maintenance of the fat body. Gene expression is modulated so that the bees are able to resist the most life-threatening challenges at the actual life stage. Different modes of maintenance and repair are regulated, apparently to meet the environmental challenges most detrimental to survival and reproductive potential for the hive. We observed a broad down-regulation of genomic and cellular maintenance in the short-lived foragers and nurse bees compared to the long-lived winter bees. Our results show that survival and reproduction of the entire hive is given priority over the individual bees, hence supporting the idea of the honeybee society as a superorganism. Our results also fit the disposable soma theory of aging.
Realization Feature of Mesenchymal Dermal Cells Tissue Engineering Construction Response in Granulating Wound Transplantation in Relation with Time-Frame  [PDF]
Elena Petersen
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2012, DOI: 10.4236/jcdsa.2012.23024
Abstract: Derma is progenitor cells sours, that are able to differentiate further in several mesodermal lineage and neural and endodermal lineage. Culture conditions, skin taking site and culture medium composition considerably contribute to it. Spheroid cultured mesenchymal dermal cells contribution to skin regeneration in granulating wound in rat model was estimated.
The influence of the NOD Nss1/Idd5 loci on sialadenitis and gene expression in salivary glands of congenic mice
Trond Hjelmervik, Anna-Karin Lindqvist, Kjell Petersen, Martina Johannesson, Anne-Kristin Stavrum, ?sa Johansson, Roland Jonsson, Rikard Holmdahl, Anne Bolstad
Arthritis Research & Therapy , 2007, DOI: 10.1186/ar2300
Abstract: Primary Sj?gren's syndrome (pSS) is an autoimmune disease (AID) hallmarked by ocular and oral dryness, known as keratoconjunctivitis sicca and xerostomia, respectively. Lymphocytic infiltrates in the lacrimal and salivary glands (SGs) are prominent features. Sj?gren's syndrome can occur alone or secondary to other autoimmune connective tissue diseases, such as rheumatoid arthritis and systemic lupus erythematosus [1].pSS is considered a multifactorial disease, in which the onset and progression are invoked by environmental factors in genetically susceptible individuals. The genetic contribution to pSS by rates of monozygotic concordance in twins has not yet been studied, whereas the concordance rate for different types of AID is ranging from 15% to 60% [2]. Familial clustering of AID has frequently been reported, and it is common for a Sj?gren's syndrome (SS) proband to have relatives with other AIDs [3,4]. There is substantial body of evidence supporting an association of SS with the major histocompatibility complex (MHC) class II region [5,6], but the association with formation of anti-Ro/La antibodies is stronger than that with the disease itself for the alleles DRB1*03 and DQB1*02 [6].Studies conducted to identify polymorphisms in cytokine genes [7] and other candidate genes associated with SS [3] have been inconclusive. However, recent gene expression studies of minor SGs from SS patients have demonstrated several cytokine genes and interferon-regulated genes to be upregulated in SS patients compared with control individuals, indicating that these genes are important players in the pathology of SS [8-11].There is a need to unravel the key mechanisms of onset and progression of multifactorial AIDs to enhance our understanding and to improve diagnostics and treatment. The search for underlying mechanisms can be facilitated by reducing the heterogeneity of environmental and genetic factors using murine models of the human condition. The nonobese diabetic (NOD) mou
Gene expression profiles in rat brain disclose CNS signature genes and regional patterns of functional specialisation
Christine Stansberg, Audun Vik-Mo, Rita Holdhus, Harald Breilid, Boleslaw Srebro, Kjell Petersen, Hugo A J?rgensen, Inge Jonassen, Vidar M Steen
BMC Genomics , 2007, DOI: 10.1186/1471-2164-8-94
Abstract: By unsupervised hierarchical clustering, we found that the transcriptome within a region was highly conserved among individual rats and that there were no systematic differences between the two hemispheres (right versus left side). Further, we identified distinct sets of genes showing significant regional enrichment. Functional annotation of each of these gene sets clearly reflected several important physiological features of the region in question, including synaptic transmission within the cortex, neurogenesis in hippocampus and G-protein-mediated signalling in striatum. In addition, we were able to reveal potentially new regional features, such as mRNA transcription- and neurogenesis-annotated activities in cerebellum and differential use of glutamate signalling between regions. Finally, we determined a set of 'CNS-signature' genes that uncover characteristics of several common neuronal processes in the CNS, with marked over-representation of specific features of synaptic transmission, ion transport and cell communication, as well as numerous novel unclassified genes.We have generated a global map of gene expression in the rat brain and used this to determine functional processes and pathways that have a regional preference or ubiquitous distribution within the CNS, respectively. The existence of shared specialised neuronal activities in CNS is interesting in a context of potential functional redundancy, and future studies should further explore the overall characteristics of CNS-specific versus region-specific gene profiles in the brain.The mammalian brain is divided into distinct regions with structural and functional similarities and differences. Based on information from decades of neuroanatomical-, neurophysiological- and neurochemical studies, in combination with more recent brain imaging findings, the huge complexity of the CNS has become increasingly evident. The subtypes of neurons, regional cytoarchitecture, variation in neurotransmitter distribution an
Gene Set Based Integrated Data Analysis Reveals Phenotypic Differences in a Brain Cancer Model
Kjell Petersen, Uros Rajcevic, Siti Aminah Abdul Rahim, Inge Jonassen, Karl-Henning Kalland, Connie R. Jimenez, Rolf Bjerkvig, Simone P. Niclou
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068288
Abstract: A key challenge in the data analysis of biological high-throughput experiments is to handle the often low number of samples in the experiments compared to the number of biomolecules that are simultaneously measured. Combining experimental data using independent technologies to illuminate the same biological trends, as well as complementing each other in a larger perspective, is one natural way to overcome this challenge. In this work we investigated if integrating proteomics and transcriptomics data from a brain cancer animal model using gene set based analysis methodology, could enhance the biological interpretation of the data relative to more traditional analysis of the two datasets individually. The brain cancer model used is based on serial passaging of transplanted human brain tumor material (glioblastoma - GBM) through several generations in rats. These serial transplantations lead over time to genotypic and phenotypic changes in the tumors and represent a medically relevant model with a rare access to samples and where consequent analyses of individual datasets have revealed relatively few significant findings on their own. We found that the integrated analysis both performed better in terms of significance measure of its findings compared to individual analyses, as well as providing independent verification of the individual results. Thus a better context for overall biological interpretation of the data can be achieved.
Late hCG administration yields more good quality embryos and favors the overall IVF outcome  [PDF]
Pu Zhang, Kjell W?nggren
Open Journal of Obstetrics and Gynecology (OJOG) , 2012, DOI: 10.4236/ojog.2012.24070
Abstract: Context: Optimal timing of hCG administration is a crucial step for successful IVF. Currently used standard hCG administration timing is not always practically possible due to weekends break or other reasons. Sometimes hCG needs to be administrated earlier or later than standard timing. Aim: To find out whether earlier or later hCG administration gives better IVF outcome. Setting and Design: A retrospective study on patients who underwent conventional IVF treatment. Methods and Material: Based on hCG timing, the patients were divided into three groups: the early hCG group where the hCG was given when less than three follicles ≥ 17 mm; the standard hCG group where the hCG was given when three or more follicles ≥ 17 mm; and the late hCG group where the hCG was given 1 to 3 days after the standard timing. The number of retrieved mature oocytes, the fertilization rate, the number of good quality embryos, the pregnancy rate and the live birth rate were compared among three groups. Statistical Analysis: x2 test, fisher exact test and Student t-test were used. Results: in total, 289 patients, 305 IVF cycles and 2784 oocytes were analyzed. The late hCG group has significantly larger number of MII oocytes, fertilized oocytes and good quality embryos per IVF cycle, when compared with the early hCG group. The fertilization rate, the pregnancy rate and the live birth rate per IVF cycle were similar among the three groups. Conclusion: Although the delayed administration of hCG did not favor IVF outcome per IVF cycle, the cumulative pregnancy rate is likely to be improved with consideration of higher yield of good quality embryos.
Diagnostic work-up of gastroenteropancreatic neuroendocrine tumors
?berg, Kjell;
Clinics , 2012, DOI: 10.6061/clinics/2012(Sup01)18
Abstract: neuroendocrine tumors are a heterogeneous group of malignancies that present a diagnostic challenge. the majority of patients (more than 60%) present with metastatic disease at diagnosis. the diagnosis is based on histopathology, imaging, and circulating biomarkers. the histopathology should contain specific neuroendocrine markers such as chromogranin a, synaptophysin, and neuron-specific enolase and also an estimate of the proliferation by ki-67 (mib1). standard imaging procedures consist of computed tomography or magnetic resonance imaging together with somatostatin receptor scintigraphy. 68ga-dota-octreotate scans will in the future replace somatostatin receptor scintigraphy because they have higher specificity and sensitivity. other positron imaging tomographic scanning tracers that will come into clinical use are 18f-dopa and 11c-5htp. neuroendocrine tumors secrete many different peptides and amines that can be used as circulating biomarkers. the most useful general marker is chromogranin a, which is both a diagnostic and prognostic marker in most neuroendocrine tumors. however, there is still a need for improved biomarkers for early detection and follow-up of patients during treatment. in addition, molecular imaging can be further developed for both detection and evaluation of treatment.
Slip-sliding away - Some Reflections on Recent Developments in Copyright and their Consequences
Kjell Nilsson
Liber Quarterly : The Journal of European Research Libraries , 2007,
Abstract: Copyright is undoubtedly a very complicated matter. For that very reason it might be useful now and again to look beyond the jungle of treaties, directives, laws, decrees and contracts, and try to establish where we are actually heading. Then we can ask ourselves whether the direction taken is the one we would like to see. My purpose in writing this article is to demonstrate how the ‘balance’, which was always considered to be a crucial goal of copyright regulation, has been gradually undermined, to the detriment of the consumers of information and culture. I will also try to illustrate how copyright has become distanced from what was once its very foundations. If we look more closely at recent developments there are primarily two factors which merit special attention, namely 1) the widespread revision of copyright legislation and 2) The increasing regulation by contract.
Molecular Imaging Radiotherapy: Theranostics for Personalized Patient Management of Neuroendocrine Tumors (NETs)
Kjell ?berg
Theranostics , 2012,
Abstract: Neuroendocrine tumors (NETs) possess unique features including expression of peptide hormone receptors as well as the capacity to concentrate and take up precursor forms of amines and peptides making hormones that are stored in secretory granules within the tumor cells (APUD). The expression of somatostatin receptors on tumor cells have been widely explored during the last two decades starting with 111In-DTPA-Octreotide as an imaging agent followed by 68Ga-DOTATOC/TATE positron emission tomography scanning. The new generation of treatment includes 90Yttrium-DOTATOC/DOTATATE as well as 177Lutetium-DOTATOC/DOTATATE/DOTANOC treatment of various subtypes of NETs. The objective response rate by these types of PRRT is in the range of 30-45% objective responses with 5-10% grade 3/4 toxicity mainly hematologic and renal toxicity. The APUD mechanism is another unique feature of NETs which have generated an interest over the last two decades to develop specific tracers including 11C-5HTP, 18F-DOPA and 11C-hydroxyefedrin. These radioactive tracers have been developed in centres with specific interest in NETs and are not available everywhere. 111In-DTPA-Octreotide is still the working horse in diagnosis and staging of metastatic NETs, but will in the future be replaced by 68Ga-DOTATOC/DOTATATE PET/CT scanning which provide higher sensitivity and specificity and is also more convenient for the patient because it is a one-stop-procedure. Both 90Yttrium-DOTATOC/DOTATATE as well as 177Lutetium-DOTATOC/DOTATATE are important new therapies for malignant metastatic NETs. However, the precise role in the treatment algorithm has to be determined in forthcoming randomized trials.
N gra bildningsfilosofiska perspektiv i synen p folkbildning
Kjell Gustavsson
Utbildning & Demokrati : Tidsskrift f?r Didaktik och Utbildningspolitik , 2002,
Abstract: Popular adult education is an action of various meanings and activities. As a pedagogical and didactical practice, questions regarding ‘‘the unique study methods” are dealt with. Further, one touches on study content as well as educational ideals and philosophies. The ambiguity of popular adult education is illustrated by emphasising four educational philosophies. In a perennialistic philosophy, popular adult education is about communicating a cultural heritage from one generation to another, which unites to a neo-humanistic education. If popular adult education emanates from scientific knowledge, which is communicated by ‘‘experts”, essentialistic philosophy and civic education are touched upon. A representative democracy is given the force of an ideal. A progressivistic philosophy puts the participant and its experiences in focus. This touches on self-education, which often is stressed in the rhetoric. Reconstructivity is made up of an education-philosophical perspective, which has deliberative discourses as a basis for a critical education and radical democracy. In the every day life of popular adult education, all of these perspectives are manifested.
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