umu.sePublications
Change search
Refine search result
1234567 1 - 50 of 869
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abdullah, Sara Alawi
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Lång respektive fördröjd provtransport ger försämrad blodprovskvalitet2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 2.
    Abdulleteef, Lina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Förekomst av humant papillomvirus i tonsillcancer i norra regionen i Sverige 2000-20122013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 3.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Liu, Li
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    3D Active Human Motion Estimation for Biomedical Applications2012In: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2012, , p. 4p. 1014-1017Conference paper (Refereed)
    Abstract [en]

    Movement disorders forbid many people from enjoying their daily lives. As with other diseases, diagnosis and analysis are key issues in treating such disorders. Computer vision-based motion capture systems are helpful tools for accomplishing this task. However Classical motion tracking systems suffer from several limitations. First they are not cost effective. Second these systems cannot detect minute motions accurately. Finally they are spatially limited to the lab environment where the system is installed. In this project, we propose an innovative solution to solve the above-mentioned issues. Mounting the camera on human body, we build a convenient, low cost motion capture system that can be used by the patient while practicing daily-life activities. We refer to this system as active motion capture, which is not confined to the lab environment. Real-time experiments in our lab revealed the robustness and accuracy of the system.

  • 4.
    Abrahamsson, Karolina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Detektion av herpesvirus i hjärnvävnad med q-PCR: Utvärdering av KAPA Express Extract kit och KAPA PROBE FORCE q-PCR kit2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 5.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, Per Jonas
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Outcome of microdialysis sampling on liver surface and parenchyma2016In: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 200, no 2, p. 480-487Article in journal (Refereed)
    Abstract [en]

    Background: To investigate whether surface microdialysis (μD) sampling in probes covered by a plastic film, as compared to noncovered and to intraparenchymatous probes, would increase the technique's sensitivity for pathophysiologic events occurring in a liver ischemia-reperfusion model. Placement of μD probes in the parenchyma of an organ, as is conventionally done, may cause adverse effects, e.g., bleeding, possibly influencing outcome.

    Methods: A transient ischemia-reperfusion model of the liver was used in six anesthetized normoventilated pigs. μD probes were placed in the parenchyma and on the liver surface. Surface probes were either left uncovered or were covered by plastic film.

    Results: Lactate and glucose levels were significantly higher in plastic film covered probes than in uncovered surface probes throughout the ischemic period. Glycerol levels were significantly higher in plastic film covered probes than in uncovered surface probes at 30 and 45 min into ischemia.

    Conclusions: Covering the μD probe increases the sensibility of the μD–technique in monitoring an ischemic insult and reperfusion in the liver. These findings confirm that the principle of surface μD works, possibly replacing need of intraparenchymatous placement of μD probes. Surface μD seemingly allows, noninvasively from an organ's surface, via the extracellular compartment, assessment of intracellular metabolic events. The finding that covered surface μD probes allows detection of local metabolic changes earlier than do intraparenchymatous probes, merit further investigation focusing on μD probe design.

  • 6. Addario, Barbara
    et al.
    Sandblad, Linda
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Persson, Karina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Backman, Lars
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Characterisation of Schizosaccharomyces pombe alpha-actinin2016In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 4, article id e1858Article in journal (Refereed)
    Abstract [en]

    The actin cytoskeleton plays a fundamental role in eukaryotic cells. Its reorganization is regulated by a plethora of actin-modulating proteins, such as a-actinin. In higher organisms, alpha-actinin is characterized by the presence of three distinct structural domains: an N-terminal actin-binding domain and a C-terminal region with EF-hand motif separated by a central rod domain with four spectrin repeats. Sequence analysis has revealed that the central rod domain of alpha-actinin from the fission yeast Schizosaccharomyces pombe consists of only two spectrin repeats. To obtain a firmer understanding of the structure and function of this unconventional alpha-actinin, we have cloned and characterized each structural domain. Our results show that this alpha-actinin isoform is capable of forming dimers and that the rod domain is required for this. However, its actin-binding and cross-linking activity appears less efficient compared to conventional alpha-actinins. The solved crystal structure of the actin-binding domain indicates that the closed state is stabilised by hydrogen bonds and a salt bridge not present in other a-actinins, which may reduce the affinity for actin.

  • 7.
    Addi, Simon
    et al.
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Hedayati-Khams, Arjang
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Poya, Amin
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Interface gap size of manually and CAD/CAM-manufactured ceramic inlays/onlays in vitro.2002In: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 30, no 1, p. 53-58Article in journal (Refereed)
    Abstract [en]

    Objectives : To determine the fit of ceramic inlays manufactured using a recently introduced CAD/CAM-system (Decim) and of two types of laboratory-made heat-pressed ceramics (IPS Empress and Opc).

    Materials and methods : Extracted human premolars were prepared to receive mesio-occlusodistal (MOD) ceramic inlays, for which 10 Denzir, 10 IPS Empress, and 10 Opc were fabricated. The Denzir restorations were produced by the manufacturer of the CAD/CAM-system, and the IPS Empress and Opc by student dental technicians. Before luting the internal fit on the diestone models and on the premolars was determined using replicas. After luting on the premolars with a resin composite the marginal and internal fit were measured. The values were analyzed statistically using ANOVA and Scheffe's test at a significance level of p<0.05.

    Results : Before luting there were no significant differences ( p>0.05) in the internal gap width between the three systems studied when placed on their matching diestone models. When placed on the premolars a significant difference ( p<0.01) in the internal fit was seen between Empress and Opc before luting, whereas there were no significant differences ( p>0.05) between Empress and Denzir and between Opc and Denzir. Between the diestone models and the premolars there were significant differences ( p<0.01) in the internal fit, except for IPS Empress. After luting there were no significant differences ( p>0.05) between IPS Empress and Denzir, whereas the marginal gap width was significantly wider ( p<0.001) for Opc than for IPS Empress and Denzir. The internal fit was significantly ( p<0.001) wider for Opc than for IPS Empress, whereas there were no significant differences ( p>0.05) between IPS Empress and Denzir or between Opc and Denzir.

    Conclusion : After luting there were only slight differences in the fit between the restorations fabricated using the three different manufacturing techniques and ceramics. Therefore, long-term follow-up studies are needed to assess the clinical significance of the slight differences between the three systems.

  • 8.
    Adhikari, Deepak
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Flohr, Gilian
    Hogeschool Leiden, Zernikedreef 11,2333 CK Leiden, The Netherlands.
    Gorre, Nagaraju
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Shen, Yan
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Yang, Hairu
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Lundin, Eva
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Lan, Zijian
    University of Louisville Health Sciences Center, Louisville, Kentucky, USA.
    Liu, Kui
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Disruption of Tsc2 in oocytes leads to overactivation of the entire pool of primordial follicles2009In: Molecular human reproduction, ISSN 1360-9947, E-ISSN 1460-2407, Vol. 15, no 12, p. 765-770Article in journal (Refereed)
    Abstract [en]

    To maintain the length of reproductive life in a woman, it is essential that most of her ovarian primordial follicles are maintained in a quiescent state to provide a continuous supply of oocytes. However, our understanding of the molecular mechanisms that control the quiescence and activation of primordial follicles is still in its infancy. In this study, we provide some genetic evidence to show that the tumor suppressor tuberous sclerosis complex 2 (Tsc2), which negatively regulates mammalian target of rapamycin complex 1 (mTORC1), functions in oocytes to maintain the dormancy of primordial follicles. In mutant mice lacking the Tsc2 gene in oocytes, the pool of primordial follicles is activated prematurely due to elevated mTORC1 activity in oocytes. This results in depletion of follicles in early adulthood, causing premature ovarian failure (POF). Our results suggest that the Tsc1-Tsc2 complex mediated suppression of mTORC1 activity is indispensable for maintenance of the dormancy of primordial follicles, thus preserving the follicular pool, and that mTORC1 activity in oocytes promotes follicular activation. Our results also indicate that deregulation of Tsc/mTOR signaling in oocytes may cause pathological conditions of the ovary such as infertility and POF.

  • 9.
    Aguilo, Francesca
    et al.
    Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
    Zakirova, Zuchra
    Nolan, Katie
    Wagner, Ryan
    Sharma, Rajal
    Hogan, Megan
    Wei, Chengguo
    Sun, Yifei
    Walsh, Martin J.
    Kelley, Kevin
    Zhang, Weijia
    Ozelius, Laurie J.
    Gonzalez-Alegre, Pedro
    Zwaka, Thomas P.
    Ehrlich, Michelle E.
    THAP1: Role in Mouse Embryonic Stem Cell Survival and Differentiation2017In: Stem Cell Reports, ISSN 2213-6711, Vol. 9, no 1, p. 92-107Article in journal (Refereed)
    Abstract [en]

    THAP1 (THAP [Thanatos-associated protein] domain-containing, apoptosis-associated protein 1) is a ubiquitously expressed member of a family of transcription factors with highly conserved DNA-binding and protein-interacting regions. Mutations in THAP1 cause dystonia, DYT6, a neurologic movement disorder. THAP1 downstream targets and the mechanism via which it causes dystonia are largely unknown. Here, we show that wild-type THAP1 regulates embryonic stem cell (ESC) potential, survival, and proliferation. Our findings identify THAP1 as an essential factor underlying mouse ESC survival and to some extent, differentiation, particularly neuroectodermal. Loss of THAP1 or replacement with a disease-causing mutation results in an enhanced rate of cell death, prolongs Nanog, Prdm14, and/or Rex1 expression upon differentiation, and results in failure to upregulate ectodermal genes. ChIP-Seq reveals that these activities are likely due in part to indirect regulation of gene expression.

  • 10.
    Ahmad, Irfan
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
    Rouf, Syed Fazle
    Sun, Lei
    Cimdins, Annika
    Shafeeq, Sulman
    Le Guyon, Soazig
    Schottkowski, Marco
    Rhen, Mikael
    Romling, Ute
    BcsZ inhibits biofilm phenotypes and promotes virulence by blocking cellulose production in Salmonella enterica serovar Typhimurium2016In: Microbial Cell Factories, ISSN 1475-2859, E-ISSN 1475-2859, Vol. 15, article id 177Article in journal (Refereed)
    Abstract [en]

    Background: Cellulose, a 1,4 beta-glucan polysaccharide, is produced by a variety of organisms including bacteria. Although the production of cellulose has a high biological, ecological and economical impact, regulatory mechanisms of cellulose biosynthesis are mostly unknown. Family eight cellulases are regularly associated with cellulose biosynthesis operons in bacteria; however, their function is poorly characterized. In this study, we analysed the role of the cellulase BcsZ encoded by the bcsABZC cellulose biosynthesis operon of Salmonella enterica serovar Typhimurium (S. Typhimurium) in biofilm related behavior. We also investigated the involvement of BcsZ in pathogenesis of S. Typhimurium including a murine typhoid fever infection model. Result: In S. Typhimurium, cellulase BcsZ with a putative periplasmic location negatively regulates cellulose biosynthesis. Moreover, as assessed with a non-polar mutant, BcsZ affects cellulose-associated phenotypes such as the rdar biofilm morphotype, cell clumping, biofilm formation, pellicle formation and flagella-dependent motility. Strikingly, although upregulation of cellulose biosynthesis was not observed on agar plate medium at 37 degrees C, BcsZ is required for efficient pathogen-host interaction. Key virulence phenotypes of S. Typhimurium such as invasion of epithelial cells and proliferation in macrophages were positively regulated by BcsZ. Further on, a bcsZ mutant was outcompeted by the wild type in organ colonization in the murine typhoid fever infection model. Selected phenotypes were relieved upon deletion of the cellulose synthase BcsA and/or the central biofilm activator CsgD. Conclusion: Although the protein scaffold has an additional physiological role, our findings indicate that the catalytic activity of BcsZ effectively downregulates CsgD activated cellulose biosynthesis. Repression of cellulose production by BcsZ subsequently enables Salmonella to efficiently colonize the host.

  • 11.
    Aisenbrey, Christopher
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Byström, Roberth
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Oliveberg, Mikael
    Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden.
    Gröbner, Gerhard
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    SOD1 associates to membranes in its folded apo-stateManuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease accompanied by misfolding and intracellular deposition of superoxide dismutase 1 (SOD1). Although the molecular details behind this misfolding process are yet poorly understood, increasing evidence suggest that SOD1 is most susceptible to misfolding in its metal-free and relatively unstable apo-state. Here, we addressed the question, if misfolding and aggregation of SOD1 involves erroneous interactions with membranes as has been implicated for the Aβ peptide in Alzheimers disease. To examine this possibility we subjected various apo SOD1 variants to the presence of different membrane systems. The results reveal that wild type apoSOD1 but to less extent destabilized ALS mutations interact with charged vesicles under physiologically relevant conditions, thereby acquiring pronounced helical structural features. As the data further show, the protein binds to the membranes by an electrostatically driven mechanism, which requires a folded apo-state conformation and a negative membrane surface potential. Unfolded SOD1 molecules show no appreciable affinity to the membrane surfaces yielding a correlation between increased stability, i. e. occupancy of folded molecules and extend of membrane association. Since this trend opposes the correlation between decreased SOD1 stability and progression of neural damage, the results suggest that membrane association is not part of the ALS mechanism. An explanation could be that the observed membrane association of apo SOD1 is reversible and does not ‘bleed out’ in irreversible aggregation as observed for other precursors of protein-misfolding diseases.

  • 12.
    Akula, Ilona
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Hjärtfunktion vid ärftlig transtyretin-amyloidos: Jämförelse av hjärtfrekvensvariabilitet och ekokardiografi mellan två amyloidfibrilltyper2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 13.
    Al Rabiey, Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Detektion av aktin i paraffinsnitt från human vävnad2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 14. Al-Anati, Lauy
    et al.
    Viluksela, Matti
    Strid, Anna
    Bergman, Åke
    Andersson, Patrik L
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Stenius, Ulla
    Högberg, Johan
    Hydroxyl metabolite of PCB 180 induces DNA damage signaling and enhances the DNA damaging effect of benzo[a]pyrene2015In: Chemico-Biological Interactions, ISSN 0009-2797, E-ISSN 1872-7786, Vol. 239, p. 164-173Article in journal (Refereed)
    Abstract [en]

    Non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) and their hydroxyl metabolites (OH-PCBs) are ubiquitous environmental contaminants in human tissues and blood. The toxicological impact of these metabolites is poorly understood. In this study rats were exposed to ultrapure PCB180 (10-1000 mg/kg bw) for 28 days and induction of genotoxic stress in liver was investigated. DNA damage signaling proteins (pChk1Ser317 and gamma H2AXSer319) were increased dose dependently in female rats. This increase was paralleled by increasing levels of the metabolite 3'-OH-PCB180. pChk1 was the most sensitive marker. In in vitro studies HepG2 cells were exposed to 1 mu M of PCB180 and 3'-OH-PCB180 or the positive control benzo[a]pyrene (BaP, 5 mu M). 3'-OH-PCB180, but not PCB180, induced CYP1A1 mRNA and gamma H2AX. CYP1A1 mRNA induction was seen at 1 h, and gamma H2AX at 3 h. The anti-oxidant N-Acetyl-L-Cysteine (NAC) completely prevented, and 17 beta-estradiol amplified the gamma H2AX induction by 3'-OH-PCB180. As 3'-OH-PCB180 induced CYP1A1, a major BaP-metabolizing and activating enzyme, interactions between 3'-OH-PCB180 and BaP was also studied. The metabolite amplified the DNA damage signaling response to BaP. In conclusion, metabolism of PCB180 to its hydroxyl metabolite and the subsequent induction of CYP1A1 seem important for DNA damage induced by PCB180 in vivo. Amplification of the response with estradiol may explain why DNA damage was only seen in female rats.

  • 15.
    Albertsson, Jakob
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Effekt av förbehandling vid detektion av muterat superoxiddismutas-1 protein: Immunohistokemisk detektion av SOD1 aggregat hos G93A transgena möss2016Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
  • 16.
    Albertsson, Jakob
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Effekt av förbehandling vid detektion av muterat superoxiddismutas-1 protein: Immunohistokemisk detektion av SOD1 aggregat hos G93A transgena möss2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 17. Alcocer, Marcos
    et al.
    Rundqvist, Louise
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Larsson, Göran
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Ber e 1 protein: the versatile major allergen from Brazil nut seeds.2012In: Biotechnology letters, ISSN 0141-5492, E-ISSN 1573-6776, Vol. 34, no 4, p. 597-610Article in journal (Refereed)
    Abstract [en]

    Due mainly to its extremely high content of sulphur amino acids, Ber e 1 protein, the major allergen from Brazil nut, has attracted much scientific and press attention. Ber e 1 was the main target protein in early biotechnology transgenic work, in early processing studies of plant storage proteins, in plant vacuolar targeting studies and as the main protein in early nutritional supplementation experiments. Ber e 1 was also one of the first food allergens to be unintentionally transferred from one plant to another and was involved in the first reported case of systemic allergic reaction caused by a food allergen transferred in semen. In this review, many of the Ber e 1 unique biotechnological and structural functions are discussed with a particular emphasis on its use as model protein for studies of intrinsic allergenicity of food proteins.

  • 18. Alex, Amal
    et al.
    Piano, Valentina
    Polley, Soumitra
    Stuiver, Marchel
    Voss, Stephanie
    Ciossani, Giuseppe
    Overlack, Katharina
    Voss, Beate
    Wohlgemuth, Sabine
    Petrovic, Arsen
    Wu, Yao-Wen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Selenko, Philipp
    Musacchio, Andrea
    Maffini, Stefano
    Electroporated recombinant proteins as tools for in vivo functional complementation, imaging and chemical biology2019In: eLIFE, E-ISSN 2050-084X, Vol. 8, article id e48287Article in journal (Refereed)
    Abstract [en]

    Delivery of native or chemically modified recombinant proteins into mammalian cells shows promise for functional investigations and various technological applications, but concerns that sub-cellular localization and functional integrity of delivered proteins may be affected remain high. Here, we surveyed batch electroporation as a delivery tool for single polypeptides and multi-subunit protein assemblies of the kinetochore, a spatially confined and well-studied subcellular structure. After electroporation into human cells, recombinant fluorescent Ndc80 and Mis12 multi-subunit complexes exhibited native localization, physically interacted with endogenous binding partners, and functionally complemented depleted endogenous counterparts to promote mitotic checkpoint signaling and chromosome segregation. Farnesylation is required for kinetochore localization of the Dynein adaptor Spindly. In cells with chronically inhibited farnesyl transferase activity, in vitro farnesylation and electroporation of recombinant Spindly faithfully resulted in robust kinetochore localization. Our data show that electroporation is well-suited to deliver synthetic and chemically modified versions of functional proteins, and, therefore, constitutes a promising tool for applications in chemical and synthetic biology.

  • 19.
    Ali, Jalal
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Fluorescerande Chlamydia trachomatis-mCherry för analys av nya antimikrobiella substanser2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 20.
    Ally Lalloo, Arshad
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Mapping the Role of ATP Binding and Hydrolysis of ClpB Domain in Francisella tularensis2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 21.
    Almeros, Isak
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Bindning av Adenovirus typ 40 till kommensala grampositiva och gramnegativa bakterier2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 22.
    Alrifaiy, Ahmed
    et al.
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Bitaraf, Nazanin
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Druzin, Michael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Lindahl, Olof
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Luleå University of Technology.
    Ramser, K
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Hypoxia on a chip: a novel approach for patch-clamp studies in a microfluidic system with full oxygen control2013In: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2013, p. 313-316Conference paper (Refereed)
    Abstract [en]

    A new approach to perform patch-clamp experiments on living cells under controlled anoxic and normoxic conditions was developed and tested. To provide an optimal control over the oxygen content and the biochemical environment a patch-clamp recording micropipette was integrated within an oxygen tight poly-methyl methacrylate (PMMA) based microchip. The oxygen content within the microfluidic chamber surrounding patch-clamp micropipette was maintained at 0.5-1.5 % by a continuous flow of artificial extracellular solution purged with nitrogen. The nerve and glial cells acutely obtained from the male rat brain were trapped by the optical tweezers and steered towards the patch-clamp micropipette through the channels of the microchip in order to achieve a close contact between the pipette and the cellular membrane. The patch-clamp recordings revealed that optical tweezers did not affect the electrophysiological properties of the tested cells suggesting that optical trapping is a safe and non-traumatizing method to manipulate living cells in the microfluidic system. Thus, our approach of combining optical tweezers and a gas-tight microfluidic chamber may be applied in various electrophysiological investigations of single cells were optimal control of the experimental conditions and the sample in a closed environment are necessary.

  • 23. Alrifaiy, Ahmed
    et al.
    Borg, Johan
    Lindahl, Olof A.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology; CMTF, Centre for Biomedical Engineering and Physics, Luleå and Umeå, Sweden; Department of Engineering Sciences and Mathematics, Luleå University of Technology.
    Ramser, Kerstin
    A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy-first investigations of single biological cells2015In: Biomedical engineering online, ISSN 1475-925X, E-ISSN 1475-925X, Vol. 14, article id 36Article in journal (Refereed)
    Abstract [en]

    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 Omega and 889.7 +/- 1.74 M Omega respectively.

  • 24. Alrifaiy, Ahmed
    et al.
    Lindahl, Olof A
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ramser, Kerstin
    Polymer-based microfluidic devices for pharmacy, biology and tissue engineering2012In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 4, no 3, p. 1349-1398Article, review/survey (Refereed)
    Abstract [en]

    This paper reviews microfluidic technologies with emphasis on applications in the fields of pharmacy, biology, and tissue engineering. Design and fabrication of microfluidic systems are discussed with respect to specific biological concerns, such as biocompatibility and cell viability. Recent applications and developments on genetic analysis, cell culture, cell manipulation, biosensors, pathogen detection systems, diagnostic devices, high-throughput screening and biomaterial synthesis for tissue engineering are presented. The pros and cons of materials like polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), polycarbonate (PC), cyclic olefin copolymer (COC), glass, and silicon are discussed in terms of biocompatibility and fabrication aspects. Microfluidic devices are widely used in life sciences. Here, commercialization and research trends of microfluidics as new, easy to use, and cost-effective measurement tools at the cell/tissue level are critically reviewed.

  • 25.
    Alrifaiy, Ahmed
    et al.
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Ramser, Kerstin
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    How to integrate a micropipette into a closed microfluidic system: absorption spectra of an optically trapped erythrocyte2011In: Biomedical Optics Express, ISSN 2156-7085, E-ISSN 2156-7085, Vol. 2, no 8, p. 2299-2306Article in journal (Refereed)
    Abstract [en]

    We present a new concept of integrating a micropipette within a closed microfluidic system equipped with optical tweezers and a UV-Vis spectrometer. A single red blood cell (RBC) was optically trapped and steered in three dimensions towards a micropipette that was integrated in the microfluidic system. Different oxygenation states of the RBC, triggered by altering the oxygen content in the microchannels through a pump system, were optically monitored by a UV-Vis spectrometer. The built setup is aimed to act as a multifunctional system where the biochemical content and the electrophysiological reaction of a single cell can be monitored simultaneously. The system can be used for other applications like single cell sorting, in vitro fertilization or electrophysiological experiments with precise environmental control of the gas-, and chemical content. 

  • 26.
    Alstermark, Bror
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Hultborn, H
    University of Copenhagen Department of Neuroscience and Pharmacology Copenhagen N. Denmark.
    Jankowska, E
    Sahlgrenska Academy, University of Gothenburg Department of Physiology Gothenburg Sweden.
    Pettersson, L-G
    Sahlgrenska Academy, University of Gothenburg Department of Physiology Gothenburg Sweden.
    Anders Lundberg (1920-2009).2010In: Experimental Brain Research, ISSN 0014-4819, E-ISSN 1432-1106, Vol. 200, no 3-4, p. 193-195Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Anders Lundberg was one of the founding editorial board members for EBR when it began its life in 1976 under the editorship of John Eccles. He was also one of the most prolific contributors to the journal with a total of 49 papers, including a series of 16 on the topic of “integration in descending motor pathways controlling the forelimb in the cat”. He continued as an editor of the journal until volume 16 when he persuaded his younger colleague Hans Hultborn to take his place. Hans is one of the authors of the obituary. –John Rothwell

  • 27.
    Alvarez, Laura
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Aliashkevich, Alena
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    de Pedro, Miguel A.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Bacterial secretion of D-arginine controls environmental microbial biodiversity2018In: The ISME Journal, ISSN 1751-7362, E-ISSN 1751-7370, Vol. 12, no 2, p. 438-450Article in journal (Refereed)
    Abstract [en]

    Bacteria face tough competition in polymicrobial communities. To persist in a specific niche, many species produce toxic extracellular effectors to interfere with the growth of nearby microbes. These effectors include the recently reported non-canonical D-amino acids (NCDAAs). In Vibrio cholerae, the causative agent of cholera, NCDAAs control cell wall integrity in stationary phase. Here, an analysis of the composition of the extracellular medium of V. cholerae revealed the unprecedented presence of D-Arg. Compared with other D-amino acids, D-Arg displayed higher potency and broader toxicity in terms of the number of bacterial species affected. Tolerance to D-Arg was associated with mutations in the phosphate transport and chaperone systems, whereas D-Met lethality was suppressed by mutations in cell wall determinants. These observations suggest that NCDAAs target different cellular processes. Finally, even though virtually all Vibrio species are tolerant to D-Arg, only a few can produce this D-amino acid. Indeed, we demonstrate that D-Arg may function as part of a cooperative strategy in vibrio communities to protect non-producing members from competing bacteria. Because NCDAA production is widespread in bacteria, we anticipate that D-Arg is a relevant modulator of microbial subpopulations in diverse ecosystems.

  • 28.
    Alvarez, Laura
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Espaillat, Akbar
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Hermoso, Juan A.
    de Pedro, Miguel A.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Peptidoglycan Remodeling by the Coordinated Action of Multispecific Enzymes2014In: Microbial Drug Resistance, ISSN 1076-6294, E-ISSN 1931-8448, Vol. 20, no 3, p. 190-198Article in journal (Refereed)
    Abstract [en]

    The peptidoglycan (PG) cell wall constitutes the main defense barrier of bacteria against environmental insults and acts as communication interface. The biochemistry of this macromolecule has been well characterized throughout the years but recent discoveries have unveiled its chemical plasticity under environmental stresses. Non-canonical D-amino acids (NCDAA) are produced and released to the extracellular media by diverse bacteria. Such molecules govern cell wall adaptation to challenging environments through their incorporation into the polymer, a widespread capability among bacteria that reveals the inherent catalytic plasticity of the enzymes involved in the cell wall metabolism. Here, we analyze the recent structural and biochemical characterization of Bsr, a new family of broad spectrum racemases able to generate a wide range of NCDAA. We also discuss the necessity of a coordinated action of PG multispecific enzymes to generate adequate levels of modification in the murein sacculus. Finally, we also highlight how this catalytic plasticity of NCDAA-incorporating enzymes has allowed the development of new revolutionary methodologies for the study of PG modes of growth and in vivo dynamics.

  • 29. Alvarez, S.
    et al.
    Calin, A.
    Sixtensdotter Graffmo, Karin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Moldovan, M.
    Krarup, C.
    PERIPHERAL MOTOR AXONS OF SOD1(G127X) MUTANT MICE ARE SUSCEPTIBLE TO ACTIVITY-DEPENDENT DEGENERATION2013In: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 241, p. 239-249Article in journal (Refereed)
    Abstract [en]

    Motor neuron disorders may be associated with mitochondrial dysfunction, and repetitive electrical impulse conduction during energy restriction has been found to cause neuronal degeneration. The aim of this study was to investigate the vulnerability of motor axons of a presymptomatic late-onset, fast-progression SOD1(G127x) mouse model of amyotrophic lateral sclerosis to long-lasting, high-frequency repetitive activity. Tibial nerves were stimulated at ankle in 7 to 8-month-old SOD1(G127X) mice when they were clinically indistinguishable from wild-type (WT) mice. The evoked compound muscle action potentials and ascending compound nerve action potentials were recorded from plantar muscles and from the sciatic nerve, respectively. Repetitive stimulation (RS) was carried out in interrupted trains of 200-Hz for 3 h. During the stimulation-sequence there was progressive conduction failure in WT and, to a lesser extent, in the SOD1(G127x). By contrast, 3 days after RS the electrophysiological responses remained reduced in the SOD1(G127x) but recovered completely in WT. Additionally, morphological studies showed Wallerian degeneration in the disease model. Nerve excitability testing by "threshold-tracking" showed that axons recovering from RS had changes in excitability suggestive of membrane hyperpolarization, which was smaller in the SOD1(G127x) than in WT. Our data provide proof-of-principle that SOD1(G127x) axons are less resistant to activity-induced changes in ion-concentrations. It is possible that in SOD1(G127x) there is inadequate energy-dependent Na+/K+ pumping, which may lead to a lethal Na+ overload. (C) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  • 30.
    Alverup, Josefin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Förekomst av bakterier i hudstrukturer med sjukdomen Hidradenitis suppurativa: propionibacterium acnes, Propionibacterium granulosum och Staphylococcus species detektion med immunofluorescens2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 31.
    Anani, Adi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Diagnostic instrument for children with reading disorders2006In: International Journal of Scientific Research, ISSN 1021-0806, Vol. 16, p. 167-170Article in journal (Refereed)
    Abstract [en]

    A simple and cost-effective wearable gaze tracking system is designed to observe the readingpattern of patients with reading disorders in order to facilitate for the work of ophthalmologists andthe multidisciplinary treating teams in making reliable diagnosis. The system constitutes of twominiaturized cameras mounted on a headset; one for eye tracking and one for the scene. The eyetracking information is combined with information extracted from the picture of the forwardlooking camera to online identify the gaze point. When reading a text the gaze point moves and areading pattern is created.

  • 32.
    Anderl, Ines
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Laboratory of Genetic Immunology, BioMediTech, University of Tampere, Tampere, Finland.
    Hultmark, Dan
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Laboratory of Genetic Immunology, BioMediTech, University of Tampere, Tampere, Finland.
    New ways to make a blood cell2015In: eLIFE, E-ISSN 2050-084X, Vol. 4, article id e06877Article in journal (Other academic)
  • 33.
    Anderson, Filippa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Förändrat uttryck av Epidermal Growth Factor Receptors ligander i androgenoberoende prostata-cancer2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 34.
    Anderson, Fredrick
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Physiological chemistry.
    β3-adrenergic antagonism alleviates weight loss associated with cancer cachexia2017Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Cancer induced cachexia (CIC) is a devastating wasting disorder affecting people with tumor diseases and is deemed responsible for approximately 20% of all cancer-related deaths. This syndrome is associated with atrophy of adipose tissue and skeletal muscle. No established treatment is available for CIC and the underlying mechanisms are unveiled. However, one proposed culprit is brown adipose tissue (BAT) and browning of white adipose tissue (WAT), which produces heat via activation uncoupling protein 1 (UCP1). The result is increased energy wasting. Β3-adrenergic receptor (ADRB3) signaling activates BAT and we hypothesized that treatment with a specific ADRB3 antagonist would mitigate energy wasting in CIC. Balb/ca nude mice implanted with the LuCAP32 human xenograft tumor was used as a model system for CIC. The mice were treated with the selective ADRB3-blocker SR59230A and the unselective ADRB1 and 2-blocker propranolol for 4 weeks. A vehicle (VEH) and non-tumor bearing (NTB) group was also used. Significant effects were seen on total body weight loss with SR-treatment compared to VEH. Similar effects were seen on the wasting of local WAT depots. When measuring body composition, we found moderate evidence that SR spares the wasting of lean mass. We were also able to show decreased gene expression of BAT-markers, as well as markers for lipolysis, in the subcutaneous WAT. This supports our main hypothesis. In conclusion, we can show that treatment with a selective ADRB3 antagonist alleviates the symptoms of CIC through decreased lipolysis and decreased browning of WAT. These findings add to the mechanistic understanding of the pathophysiology of CIC and could be a potential treatment strategy for this syndrome.

  • 35.
    Andersson, Christopher
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Gripenland, Jonas
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Johansson, Jörgen
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Using the chicken embryo to assess virulence of Listeria monocytogenes and to model other microbial infections2015In: Nature Protocols, ISSN 1754-2189, E-ISSN 1750-2799, Vol. 10, no 8, p. 1155-1164Article in journal (Refereed)
    Abstract [en]

    Microbial infections are a global health problem, particularly as microbes are continually developing resistance to antimicrobial treatments. An effective and reliable method for testing the virulence of different microbial pathogens is therefore a useful research tool. This protocol describes how the chicken embryo can be used as a trustworthy, inexpensive, ethically desirable and quickly accessible model to assess the virulence of the human bacterial pathogen Listeria monocytogenes, which can also be extended to other microbial pathogens. We provide a step-by-step protocol and figures and videos detailing the method, including egg handling, infection strategies, pathogenicity screening and isolation of infected organs. From the start of incubation of the fertilized eggs, the protocol takes <4 weeks to complete, with the infection part taking only 3 d. We discuss the appropriate controls to use and potential adjustments needed for adapting the protocol for other microbial pathogens.

  • 36.
    Andersson, Eva-Lotta
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Hernell, Olle
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Bläckberg, Lars
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Physiological chemistry.
    Fält, Helen
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Lindquist, Susanne
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Bile salt-stimulated lipase and pancreatic lipase-related protein 2: key enzymes for lipid digestion in the newborn examined using the Caco-2 cell line2011In: Journal of Lipid Research, ISSN 0022-2275, E-ISSN 1539-7262, Vol. 52, no 11, p. 1949-1956Article in journal (Refereed)
    Abstract [en]

    In rodents, bile salt-stimulated lipase (BSSL) and pancreatic lipase-related protein 2 (PLRP2) are the dominant lipases expressed in the exocrine pancreas in early life, when milk is the main food. The aim of the present study was to evaluate if BSSL and PLRP2 are also key enzymes in neonatal intestinal fat digestion. Using Caco-2 cells as a model for the small intestinal epithelium, purified human enzymes were incubated in the apical chamber with substrates and bile salt concentrations resembling the milieu of the small intestine of newborn infants. BSSL and PLRP2 hydrolyzed triglycerides (TG) to free fatty acids (FA) and glycerol. The cells took up the FA, which were reesterfied to TG. Together, BSSL and PLRP2 have a synergistic effect, increasing cellular uptake 4-fold compared to the sum of each lipase alone. A synergistic effect was also observed with retinyl ester as a substrate. PLRP2 hydrolyzed cholesteryl ester but not as efficiently as BSSL, and the two had an additive rather than synergistic effect. We conclude the key enzymes in intestinal fat digestion are different in newborns than later in life. Further studies are needed to fully understand this difference and its implication for designing optimal neonatal nutrition.

  • 37.
    Andersson, Kennet
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Assessment of cerebrospinal fluid system dynamics: novel infusion protocol, mathematical modelling and parameter estimation for hydrocephalus investigations2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Patients with idiopathic normal pressure hydrocephalus (INPH) have a disturbance in the cerebrospinal fluid (CSF) system. The treatment is neurosurgical – a shunt is placed in the CSF system. The infusion test is used to assess CSF system dynamics and to aid in the selection of patients that will benefit from shunt surgery. The infusion test can be divided into three parts: a mathematical model, an infusion protocol and a parameter estimation method. A non-linear differential equation is used to mathematically describe the CSF system, where two important parameters are the outflow conductance (Cout) and the Pressure Volume Index (PVI). These are used both for clinical and research purposes. The analysis methods for the non-linear CSF system have limited the infusion protocols of presently used infusion investigations. They come with disadvantages such as long investigation time, no estimation of PVI and no measure of the reliability of the estimates.

    The aim of this dissertation was to develop and evaluate novel methods for infusion protocols, mathematical modelling and parameter estimation methods for assessment of CSF system dynamics.

    The infusion protocols and parameter estimation methods in current use, constant pressure infusion (CPI), constant infusion and bolus infusion, were investigated. The estimates of Cout were compared, both on an experimental set-up and on 20 INPH patients. The results showed that the bolus method produced a significantly higher Cout than the other methods. The study suggested a method with continuous infusion for estimating Cout and emphasized that standardization of Cout measurement is necessary.

    The non-linear model of the CSF system was further developed. The ability to model physiological variations that affect the CSF system was incorporated into the model and it was transformed into a linear time-invariant system. This enabled the use of methods developed for identification of such systems. The underlying model for CSF absorption was discussed and the effect of baseline resting pressure (Pr) in the analysis on the estimation of Cout was explored using two different analyses, with and without Pr.

    A novel infusion protocol with an oscillating pressure pattern was introduced. This protocol was theoretically better suited for the CSF system characteristics. Three new parameter estimation methods were developed. The adaptive observer was developed from the original non-linear model of the CSF system and estimated Cout in real time. The prediction error method (PEM) and the robust simulation error (RSE) method were based on the transformed linear system, and they estimated both Cout and PVI with confidence intervals in real time. Both the oscillating pressure pattern and the reference CPI protocol were performed on an experimental set-up of the CSF system and on 47 hydrocephalus patients. The parameter estimation methods were applied to the data, and the RSE method produced estimates of Cout that were in good agreement with the reference method and allowed for an individualized and considerably reduced investigation time.

    In summary, current methods have been investigated and a novel approach for assessment of CSF system dynamics has been presented. The Oscillating Pressure Infusion method, which includes a new infusion protocol, a further developed mathematical model and new parameter estimation methods has resulted in an improved way to perform infusion investigations and should be used when assessing CSF system dynamics. The advantages of the new approach are the pressure-regulated infusion protocol, simultaneous estimation of Cout and PVI and estimates of reliability that allow for an individualized investigation time.

  • 38.
    Andersson, Paulina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Autolog adsorptionsteknik hos nytransfunderad patient med autoantikroppar – en experimentell metodutvärdering.2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 39.
    Andersson, Simon
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Binding of Norovirus-Like Particles to Integrin Expressing CHO Cells2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 40.
    Andersson, Viktor
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Vänsterkammarfunktion hos cancerpatienter som erhållit hjärttoxisk behandling: Intraobservatörvariabilitet för systoliska funktionsmått utvärderad med ekokardiografi2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 41. Andre, Kadri
    et al.
    Kampman, Olli
    Illi, Ari
    Viikki, Merja
    Setala-Soikkeli, Eija
    Mononen, Nina
    Lehtimaki, Terho
    Haraldsson, Susann
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Koivisto, Pasi A.
    Leinonen, Esa
    SERT and NET polymorphisms, temperament and antidepressant response2015In: Nordic Journal of Psychiatry, ISSN 0803-9488, E-ISSN 1502-4725, Vol. 69, no 7, p. 531-538Article in journal (Refereed)
    Abstract [en]

    Background: The genetic variations in norepinephrine transporter (NET) and serotonin transporter (SERT) genes have been associated with personality traits, several psychiatric disorders and the efficacy of antidepressant treatment. Aims: We investigated the separate effects and possible interactions between NET T-182C (rs2242446) and SERT 5-HTTLPR (rs4795541) polymorphisms on selective serotonin reuptake inhibitors (SSRI) treatment response and temperamental traits assessed by the Temperament and Character Inventory (TCI) in a clinical sample of subjects with major depressive disorder (MDD). Methods: Our sample of 97 patients with major depression completed the 107-item TCI temperament questionnaire (version IX) at the initial assessment of the study and after 6 weeks of follow-up. All subjects received selective SSRI medications. Temperament dimension scores at baseline (1) and endpoint (2) during antidepressant treatment were analyzed between NET and SERT genotypes. Results: SS-genotype of 5-HTTLPR was associated with higher baseline Persistence scores than SL- or LL-genotype. A corresponding but weaker association was found at endpoint. No differences were found between 5-HTTLPR genotypes and other temperament dimensions and 5-HTTLPR genotypes had no effect on treatment response. Conclusions: Our results suggest that the SS-genotype of 5-HTTLPR is associated with Persistence scores in patients with MDD. Higher Persistence could be viewed as a negative trait when recovering from stress and its association with short and "weaker" S-allele may be related to less efficient serotonin neurotransmission, possibly resulting in less effective coping strategies on a behavioral level.

  • 42. Arab, Khelifa
    et al.
    Park, Yoon Jung
    Lindroth, Anders M.
    Schaefer, Andrea
    Oakes, Christopher
    Weichenhan, Dieter
    Lukanova, Annekatrin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Lundin, Eva
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Risch, Angela
    Meister, Michael
    Dienemann, Hendrik
    Dyckhoff, Gerhard
    Herold-Mende, Christel
    Grummt, Ingrid
    Niehrs, Christof
    Plass, Christoph
    Long Noncoding RNA TARID Directs Demethylation and Activation of the Tumor Suppressor TCF21 via GADD45A2014In: Molecular Cell, ISSN 1097-2765, E-ISSN 1097-4164, Vol. 55, no 4, p. 604-614Article in journal (Refereed)
    Abstract [en]

    DNA methylation is a dynamic and reversible process that governs gene expression during development and disease. Several examples of active DNA demethylation have been documented, involving genome-wide and gene-specific DNA demethylation. How demethylating enzymes are targeted to specific genomic loci remains largely unknown. We show that an antisense lncRNA, termed TARID (for TCF21 antisense RNA inducing demethylation), activates TCF21 expression by inducing promoter demethylation. TARID interacts with both the TCF21 promoter and GADD45A (growth arrest and DNA-damage-inducible, alpha), a regulator of DNA demethylation. GADD45A in turn recruits thymine-DNA glycosylase for base excision repair-mediated demethylation involving oxidation of 5-methylcytosine to 5-hydroxymethylcytosine in the TCF21 promoter by ten-eleven translocation methylcytosine dioxygenase proteins. The results reveal a function of lncRNAs, serving as a genomic address label for GADD45A-mediated demethylation of specific target genes.

  • 43.
    Arabi, Thyba
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Cajal cellernas roll i mag-tarm komplikationer hos patienter med transtyretin amyloidos2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 44. Arenz, Stefan
    et al.
    Abdelshahid, Maha
    Sohmen, Daniel
    Payoe, Roshani
    Starosta, Agata L.
    Berninghausen, Otto
    Hauryliuk, Vasili
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). University of Tartu, Institute of Technology, Tartu, Estonia.
    Beckmann, Roland
    Wilson, Daniel N.
    The stringent factor RelA adopts an open conformation on the ribosome to stimulate ppGpp synthesis2016In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 44, no 13, p. 6471-6481Article in journal (Refereed)
    Abstract [en]

    Under stress conditions, such as nutrient starvation, deacylated tRNAs bound within the ribosomal A-site are recognized by the stringent factor RelA, which converts ATP and GTP/GDP to (p)ppGpp. The signaling molecules (p) ppGpp globally rewire the cellular transcriptional program and general metabolism, leading to stress adaptation. Despite the additional importance of the stringent response for regulation of bacterial virulence, antibiotic resistance and persistence, structural insight into how the ribosome and deacylated-tRNA stimulate RelA-mediated (p)ppGpp has been lacking. Here, we present a cryo-EM structure of RelA in complex with the Escherichia coli 70S ribosome with an average resolution of 3.7 angstrom and local resolution of 4 to > 10 angstrom for RelA. The structure reveals that RelA adopts a unique 'open' conformation, where the C-terminal domain (CTD) is intertwined around an A/T-like tRNA within the intersubunit cavity of the ribosome and the N-terminal domain (NTD) extends into the solvent. We propose that the open conformation of RelA on the ribosome relieves the autoinhibitory effect of the CTD on the NTD, thus leading to stimulation of (p)ppGpp synthesis by RelA.

  • 45. Arfvidsson, Berndt
    et al.
    Nilsson, Torbjörn K
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Norgren, Lars
    S100B concentrations increase perioperatively in jugular vein blood despite limited metabolic and inflammatory response to clinically uneventful carotid endarterectomy2015In: Clinical Chemistry and Laboratory Medicine, ISSN 1434-6621, E-ISSN 1437-4331, Vol. 53, no 1, p. 111-117Article in journal (Refereed)
    Abstract [en]

    Background: Our aim was to test the hypothesis that metabolic and inflammatory responses of the brain perioperatively during carotid endarterectomy (CEA) might affect blood brain barrier (BBB) integrity. Methods: Twenty patients with >70% stenosis of internal carotid artery (ICA) were prospectively included. Surgery was performed under general anaesthesia. Blood was sampled from ipsilateral internal jugular vein and radial artery: just before, during, and after ICA clamping S100B protein, glucose, lactate, 20 amino acids, and key cytokines were analysed. Results: Jugular vein S100B increased during clamping and reperfusion, while a marginal systemic increase was recorded, unrelated to stump pressure during clamping. Glucose increased during clamping in jugular vein blood and even more systemically, while jugular lactate values were higher than systemic values initially. Most amino acids did not differ significantly between jugular vein and systemic levels: glutamic acid and aspartic acid decreased during surgery while asparagine increased. Jugular vein interleukin (IL)-6 showed a transient non-significant increase during clamping and decreased systemically. IL-8 and IL-10 increased over time. Conclusions: Rising jugular vein S100B concentrations indicated reduced BBB integrity, and marginal secondary increase of S100B systemically. Limited ischaemic effects on the brain during cross-clamping, unrelated to S100B concentrations, were confirmed by lower brain glucose levels and higher lactate levels than in systemic blood. The lack of increased jugular vein glutamic acid disproves any major ischaemic brain injury following CEA. The inflammatory response was limited, did not differ greatly between jugular and systemic blood, and was unrelated to S100B.

  • 46.
    Arnqvist, Jennifer
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Optimering av lymfocytfraktionering med AutoMACS Pro för biobankning av hematologiska maligniteter2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 47. Arsov, S.
    et al.
    Trajceska, L.
    van Oeveren, W.
    Smit, A. J.
    Vidimliski, P. Dzekova
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sikole, A.
    Rakhorst, G.
    Graaff, R.
    The use of a skin age reader to evaluate risk of cvd and mortality in dialysis patients2011In: International Journal of Artificial Organs, ISSN 0391-3988, E-ISSN 1724-6040, Vol. 34, no 8, p. 606-606Article in journal (Other academic)
  • 48. Arsov, Stefan
    et al.
    Graaff, Reindert
    van Oeveren, Wim
    Stegmayr, Bernd
    Sikole, Aleksandar
    Rakhorst, Gerhard
    Smit, Andries J.
    Advanced glycation end-products and skin autofluorescence in end-stage renal disease: a review2014In: Clinical Chemistry and Laboratory Medicine, ISSN 1434-6621, E-ISSN 1437-4331, Vol. 52, no 1, SI, p. 11-20Article, review/survey (Refereed)
    Abstract [en]

    Chronic kidney disease (CKD), especially in its end stage, is marked by extremely high cardiovascular rates of morbidity and mortality; hemodialysis patients have a five-fold shorter life expectancy than healthy subjects of the same age. In CKD the metabolic products that accumulate in the body are so-called uremic toxins. These include advanced glycation end-products (AGE). AGE levels are markedly increased in CKD patients not only because of impaired excretion but also because of increased production. AGE formation has initially been described as a non-enzymatic reaction between proteins and glucose in the so-called Maillard reaction, but they are also more rapidly formed during oxidative stress and subsequent formation of reactive carbonyl compounds like (methyl) glyoxal. AGE accumulate in tissue where they cross-link with proteins, e. g., collagen, inducing tissue stiffening of blood vessels and skin. They may also interact with receptor of AGE (RAGE) and other receptors, which lead to activation of intracellular transduction mechanisms resulting in cytokine release and further tissue damage in CKD. The accumulation of AGE in the skin can be measured non-invasively using autofluorescence. The skin autofluorescence is a strong marker of cardiovascular mortality in CKD. The focus of this review is on the role of tissue and plasma AGE, and of skin autofluorescence as a proxy of tissue AGE accumulation, in the increase in cardiovascular disease in end stage renal disease (ESRD). This review will also present the possibility of reducing the AGE accumulation in ESRD patients using the following five methods: 1) use of low AGE peritoneal dialysis solutions; 2) use of advanced hemodialysis techniques; 3) use of AGE reducing drugs; 4) optimizing the nutrition of hemodialysis patients; and 5) renal transplantation.

  • 49. Arsov, Stefan
    et al.
    Trajceska, Lada
    van Oeveren, Wim
    Smit, Andries J
    Dzekova, Pavlina
    Stegmayr, Bernd
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sikole, Aleksandar
    Rakhorst, Gerhard
    Graaff, Reindert
    Increase in skin autofluorescence and release of heart-type fatty acid binding protein in plasma predicts mortality of hemodialysis patients2013In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 37, no 7, p. E114-E122Article in journal (Refereed)
    Abstract [en]

    Advanced glycation end-products (AGEs) are uremic toxins that accumulate progressively in hemodialysis (HD) patients. The aim of this study was to assess the 1-year increase in skin autofluorescence (DAF), a measure of AGEs accumulation and plasma markers, as predictors of mortality in HD patients. One hundred sixty-nine HD patients were enrolled in this study. Skin autofluorescence was measured twice, 1 year apart using an AGE Reader (DiagnOptics Technologies BV, Groningen, The Netherlands). Besides routine blood chemistry, additional plasma markers including superoxide dismutase, myeloperoxydase, intercellular adhesion molecule 1 (ICAM-1), C-reactive protein (hs-CRP), heart-type fatty acid binding protein (H-FABP), and von Willebrand factor were measured at baseline. The mortality of HD patients was followed for 36 months. Skin autofluorescence values of the HD patients at the two time points were significantly higher (P < 0.001) than those of healthy subjects of the same age. Mean 1-year DAF of HD patients was 0.16 +/- 0.06, which was around seven-to ninefold higher than 1-year DAF in healthy subjects. Multivariate Cox regression showed that age, hypertension, 1-year DAF, hs-CRP, ICAM-1, and H-FABP were independent predictors of overall mortality. Hypertension, 1-year DAF, hs-CRP, and H-FABP were also independent predictors of cardiovascular mortality. One-year DAF and plasma H-FABP, used separately and in combination, are strong predictors of overall and cardiovascular mortality in HD patients.

  • 50. Asan, Noor Badariah
    et al.
    Noreland, Daniel
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Hassan, Emadeldeen
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Department of Electronics and Electrical Communications, Menoufia University, Menouf, Egypt.
    Shah, Syaiful Redzwan Mohd
    Rydberg, Anders
    Blokhuis, Taco J.
    Carlsson, Per-Ola
    Voigt, Thiemo
    Augustine, Robin
    Intra-body microwave communication through adipose tissue2017In: Healthcare technology letters, E-ISSN 2053-3713, Vol. 4, no 4, p. 115-121Article in journal (Refereed)
    Abstract [en]

    The human body can act as a medium for the transmission of electromagnetic waves in the wireless body sensor networks context. However, there are transmission losses in biological tissues due to the presence of water and salts. This Letter focuses on lateral intra-body microwave communication through different biological tissue layers and demonstrates the effect of the tissue thicknesses by comparing signal coupling in the channel. For this work, the authors utilise the R-band frequencies since it overlaps the industrial, scientific and medical radio (ISM) band. The channel model in human tissues is proposed based on electromagnetic simulations, validated using equivalent phantom and ex-vivo measurements. The phantom and ex-vivo measurements are compared with simulation modelling. The results show that electromagnetic communication is feasible in the adipose tissue layer with a low attenuation of approximate to 2 dB per 20 mm for phantom measurements and 4 dB per 20 mm for ex-vivo measurements at 2 GHz. Since the dielectric losses of human adipose tissues are almost half of ex-vivo tissue, an attenuation of around 3 dB per 20 mm is expected. The results show that human adipose tissue can be used as an intra-body communication channel.

1234567 1 - 50 of 869
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf