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  • 1. Abdelfatah Possnert, Heba
    Detection of Thymidine Kinase 1 Activity in Whole Blood Using an Oligonucleotide System2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today’s medical science studies, many tumor markers are being used to monitor cancer cell proliferation, but the number of assays for analysis of these markers are few. The aim of this study was to find an easier and more time-efficient way to measure the activity of a specific tumor marker called tymidine kinase 1 (TK1). This tumor marker is an important enzyme involved in cell proliferation and is a key enzyme in the salvage pathway. TK1 activity is related to the occurrence of hematological malignancies and cell activity and therefore have been used as a marker when monitoring this group of patients in treatment. Measurement of the enzyme activity in this study was performed by using an oligonucleotide assay. Detection of the enzyme activity in whole blood and in plasma has not previously been shown. The TK1 activity measured in whole blood and plasma correlated with TK1 activity measured in serum (R2=0,8651 and R2 =0,9845, respectively). It was found that it is possible to determine the TK1 activity in whole blood but only if the activity was measured on the same day as the blood samples were taken. The results shows that the activity measurement of TK1 in plasma and whole blood can be used as a marker to verify patients' therapy in cancer care. This study is only the beginning and further investigations should be made in the future to determine if the method that is subject to this study has the requested effects.

  • 2.
    Abelson, Klas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Acetylcholine in Spinal Pain Modulation: An in vivo Study in the Rat2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The spinal cord is an important component in the processing and modulation of painful stimuli. Nerve signals from the periphery are relayed and further conducted to the brain (nociception) in the spinal cord, and the most essential modulation of painful information (antinociception) occurs here. Several neurotransmitters are involved in spinal pain modulation, among them acetylcholine. However, the role of acetylcholine has previously been little investigated.

    In the present thesis, the acetylcholine release in the spinal cord was studied in vivo. By using spinal microdialysis on anaesthetised rats, the effects on the intraspinal acetylcholine release of various receptor ligands and analgesic agents were examined. This, together with pain behavioural tests and in vitro pharmacological assays, was used to evaluate the role of acetylcholine in spinal pain modulation. The four studies in this thesis resulted in the following conclusions:

    An increased release of spinal acetylcholine is associated with an elevated pain threshold, while a decreased acetylcholine release is associated with hyperalgesia, as seen after systemic treatment with a muscarinic agonist and an antagonist.

    Lidocaine is a potent analgesic when given systemically. It was found to produce an increase of intraspinal acetylcholine after intravenous injection of analgesic doses. This effect was attenuated after muscarinic, and abolished after nicotinic, receptor blockade.

    Various a2-adrenergic ligands, associated with nociceptive or antinociceptive effects, were found to affect intraspinal acetylcholine release via action on nicotinic receptors.

    Finally, the involvement of spinal acetylcholine in the analgesic effects of aspirin and paracetamol was examined. It was found that spinal acetylcholine could participate in the analgesic effects of aspirin, but not of paracetamol.

    The present thesis provides data that clearly demonstrate a relationship between intraspinal acetylcholine and antinociception, and elucidate interactions between acetylcholine and other mechanisms that mediate antinociception in the spinal cord.

    List of papers
    1. Intravenously administered oxotremorine and atropine, in doses known to affect pain threshold, affect the intraspinal release of acetylcholine in rats
    Open this publication in new window or tab >>Intravenously administered oxotremorine and atropine, in doses known to affect pain threshold, affect the intraspinal release of acetylcholine in rats
    2002 (English)In: Pharmacology and Toxicology, ISSN 0901-9928, E-ISSN 1600-0773, Vol. 90, no 4, p. 187-192Article in journal (Refereed) Published
    Abstract [en]

    Abstract:Both systemically and intrathecally administered cholinergic agonists produce antinociception while cholinergic antagonists decrease pain threshold. The mechanism and the site of action of these substances are not known. In the present study it was hypothesized that systemically administered muscarinic agonists and antagonists modify nociceptive threshold by affecting intraspinal release of acetylcholine (ACh). Catheters were inserted into the femoral vein in rats maintained on isoflurane anaesthesia for administration of oxotremorine (10–300 μg/kg) and atropine (0.1, 10, 5000 μg/kg). Spinal microdialysis probes were placed intraspinally at approximately the C2–C5 spinal level for sampling of acetylcholine and dialysis delivery of atropine (0.1, 1, 10 nM). Additionally, the tail-flick behaviour was tested on conscious rats injected intraperitoneally with saline, atropine (10, 100 and 5000 μg/kg), or subcutaneously with oxotremorine (30, 100, 300 μg/kg). Subcutaneous administration of oxotremorine (30, 100, 300 μg/kg) significantly increased the tail-flick latency. These doses of oxotremorine dose-dependently increased the intraspinal release of acetylcholine. Intravenously administered atropine, in a dose that produced hyperalgesia (5000 μg/kg) in the tail-flick test, significantly decreased the intraspinal release of acetylcholine. Our results suggest an association between pain threshold and acetylcholine release in spinal cord. It is also suggested that an approximately 30% increase in basal ACh release produces antinociception and that a 30% decrease in basal release produces hyperalgesia.

    Place, publisher, year, edition, pages
    Blackwell, 2002
    National Category
    Biomedical Laboratory Science/Technology
    Identifiers
    urn:nbn:se:uu:diva-7215 (URN)10.1034/j.1600-0773.2002.900403.x (DOI)
    Available from: 2006-10-18 Created: 2006-10-18 Last updated: 2017-12-14Bibliographically approved
    2. Intravenously administered lidocaine in therapeutic doses increases the intraspinal release of acetylcholine in rats
    Open this publication in new window or tab >>Intravenously administered lidocaine in therapeutic doses increases the intraspinal release of acetylcholine in rats
    2002 (English)In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 317, no 2, p. 93-6Article in journal (Refereed) Published
    Abstract [en]

    The local anesthetic lidocaine suppresses different pain conditions when administered systemically. Part of the antinociceptive effect appears to be mediated via receptor mechanisms. We have previously shown that muscarinic and nicotinic agonists that produce antinociception increase the intraspinal release of acetylcholine. In the present study it was hypothesized that systemically administered lidocaine is acting through the same mechanisms as cholinergic agonists and affects the intraspinal release of acetylcholine. Microdialysis probes were placed in anesthetized rats for sampling of acetylcholine. Ten and 30 mg/kg lidocaine injected intravenously significantly increased the intraspinal release of acetylcholine. The effect of lidocaine could be reduced by pretreatment with intraspinally administered atropine or mecamylamine. Our results suggest that the antinociceptive effect produced by systemically administered lidocaine is mediated through an action on muscarinic and nicotinic receptors.

    Place, publisher, year, edition, pages
    Elsevier, 2002
    Keywords
    Lidocaine; Spinal cord; Pain; Microdialysis; Acetylcholine; Muscarinic; Nicotinic
    National Category
    Biomedical Laboratory Science/Technology
    Identifiers
    urn:nbn:se:uu:diva-7227 (URN)10.1016/S0304-3940(01)02440-5 (DOI)
    Available from: 2006-10-24 Created: 2006-10-24 Last updated: 2017-12-14Bibliographically approved
    3. The effects of the alpha2-adrenergic receptor agonists clonidine and rilmenidine, and antagonists yohimbine and efaroxan, on the spinal cholinergic receptor system in the rat
    Open this publication in new window or tab >>The effects of the alpha2-adrenergic receptor agonists clonidine and rilmenidine, and antagonists yohimbine and efaroxan, on the spinal cholinergic receptor system in the rat
    2004 (English)In: Basic & Clinical Pharmacology & Toxicology, ISSN 1742-7835, E-ISSN 1742-7843, Vol. 94, no 4, p. 153-60Article in journal (Refereed) Published
    Abstract [en]

    Cholinergic agonists produce spinal antinociception via mechanisms involving an increased release of intraspinalacetylcholine. The cholinergic receptor system interacts with several other receptor types, such as a2-adrenergic receptors.To fully understand these interactions, the effects of various receptor ligands on the cholinergic system must be investigatedin detail. This study was initiated to investigate the effects of the a2-adrenergic receptor agonists clonidine and rilmenidineand the a2-adrenergic receptor antagonists yohimbine and efaroxan on spinal cholinergic receptors in the rat. Spinalmicrodialysis was used to measure in vivo changes of acetylcholine after administration of the ligands, with or withoutnicotinic receptor blockade. In addition, in vitro binding properties of the ligands on muscarinic and nicotinic receptorswere investigated. It was found that clonidine and rilmenidine increased, while yohimbine decreased spinal acetylcholinerelease. Efaroxan affected acetylcholine release differently depending on concentration. Nicotinic receptor blockade atten-uated the effect of all ligands. All ligands showed poor binding affinity for muscarinic receptors. On the other hand, allligands possessed affinity for nicotinic receptors. Clonidine and yohimbine binding was best fit to a one site binding curveand rilmenidine and efaroxan to a two site binding curve. The present study demonstrates that the tested a2-adrenergicreceptor ligands affect intraspinal acetylcholine release in the rat evoked by nicotinic receptor mechanisms in vivo, andthat they possess binding affinity to nicotinic receptors in vitro. The binding of a2-adrenergic receptor ligands to nicotinicreceptors might affect the intraspinal release of acetylcholine.

    Place, publisher, year, edition, pages
    Blackwell, 2004
    National Category
    Biomedical Laboratory Science/Technology
    Identifiers
    urn:nbn:se:uu:diva-92739 (URN)10.1111/j.1742-7843.2004.pto940401.x (DOI)15078339 (PubMedID)
    Available from: 2005-03-30 Created: 2005-03-30 Last updated: 2017-12-14Bibliographically approved
    4. Spinal cholinergic involvement after treatment with aspirin and paracetamol in rats
    Open this publication in new window or tab >>Spinal cholinergic involvement after treatment with aspirin and paracetamol in rats
    2004 In: Neurosci. Lett., ISSN 0304-3940, Vol. 368, no 1, p. 116-120Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-92740 (URN)
    Available from: 2005-03-30 Created: 2005-03-30Bibliographically approved
  • 3.
    Abelson, Klas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Hau, Jann
    Carlsson, Hans-Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Undergraduate and postgraduate students' responses to mandatory courses (FELASA category C) in laboratory animal science 1997-20032005In: Internationalisation and Harmonisation of Laboratory Animal Care and Use Issues: Proceedings of the Ninth FELASA Symposium 14-17 June 2004, Nantes, France / [ed] M. R. Gamble, 2005Conference paper (Other academic)
  • 4.
    Abelson, Klas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Höglund, Urban
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Intravenously administered lidocaine in therapeutic doses increases the intraspinal release of acetylcholine in rats2002In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 317, no 2, p. 93-6Article in journal (Refereed)
    Abstract [en]

    The local anesthetic lidocaine suppresses different pain conditions when administered systemically. Part of the antinociceptive effect appears to be mediated via receptor mechanisms. We have previously shown that muscarinic and nicotinic agonists that produce antinociception increase the intraspinal release of acetylcholine. In the present study it was hypothesized that systemically administered lidocaine is acting through the same mechanisms as cholinergic agonists and affects the intraspinal release of acetylcholine. Microdialysis probes were placed in anesthetized rats for sampling of acetylcholine. Ten and 30 mg/kg lidocaine injected intravenously significantly increased the intraspinal release of acetylcholine. The effect of lidocaine could be reduced by pretreatment with intraspinally administered atropine or mecamylamine. Our results suggest that the antinociceptive effect produced by systemically administered lidocaine is mediated through an action on muscarinic and nicotinic receptors.

  • 5.
    Abelson, Klas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Höglund, Urban
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Intravenously administered oxotremorine and atropine, in doses known to affect pain threshold, affect the intraspinal release of acetylcholine in rats2002In: Pharmacology and Toxicology, ISSN 0901-9928, E-ISSN 1600-0773, Vol. 90, no 4, p. 187-192Article in journal (Refereed)
    Abstract [en]

    Abstract:Both systemically and intrathecally administered cholinergic agonists produce antinociception while cholinergic antagonists decrease pain threshold. The mechanism and the site of action of these substances are not known. In the present study it was hypothesized that systemically administered muscarinic agonists and antagonists modify nociceptive threshold by affecting intraspinal release of acetylcholine (ACh). Catheters were inserted into the femoral vein in rats maintained on isoflurane anaesthesia for administration of oxotremorine (10–300 μg/kg) and atropine (0.1, 10, 5000 μg/kg). Spinal microdialysis probes were placed intraspinally at approximately the C2–C5 spinal level for sampling of acetylcholine and dialysis delivery of atropine (0.1, 1, 10 nM). Additionally, the tail-flick behaviour was tested on conscious rats injected intraperitoneally with saline, atropine (10, 100 and 5000 μg/kg), or subcutaneously with oxotremorine (30, 100, 300 μg/kg). Subcutaneous administration of oxotremorine (30, 100, 300 μg/kg) significantly increased the tail-flick latency. These doses of oxotremorine dose-dependently increased the intraspinal release of acetylcholine. Intravenously administered atropine, in a dose that produced hyperalgesia (5000 μg/kg) in the tail-flick test, significantly decreased the intraspinal release of acetylcholine. Our results suggest an association between pain threshold and acetylcholine release in spinal cord. It is also suggested that an approximately 30% increase in basal ACh release produces antinociception and that a 30% decrease in basal release produces hyperalgesia.

  • 6.
    Abelson, Klas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Höglund, Urban
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    The effects of the alpha2-adrenergic receptor agonists clonidine and rilmenidine, and antagonists yohimbine and efaroxan, on the spinal cholinergic receptor system in the rat2004In: Basic & Clinical Pharmacology & Toxicology, ISSN 1742-7835, E-ISSN 1742-7843, Vol. 94, no 4, p. 153-60Article in journal (Refereed)
    Abstract [en]

    Cholinergic agonists produce spinal antinociception via mechanisms involving an increased release of intraspinalacetylcholine. The cholinergic receptor system interacts with several other receptor types, such as a2-adrenergic receptors.To fully understand these interactions, the effects of various receptor ligands on the cholinergic system must be investigatedin detail. This study was initiated to investigate the effects of the a2-adrenergic receptor agonists clonidine and rilmenidineand the a2-adrenergic receptor antagonists yohimbine and efaroxan on spinal cholinergic receptors in the rat. Spinalmicrodialysis was used to measure in vivo changes of acetylcholine after administration of the ligands, with or withoutnicotinic receptor blockade. In addition, in vitro binding properties of the ligands on muscarinic and nicotinic receptorswere investigated. It was found that clonidine and rilmenidine increased, while yohimbine decreased spinal acetylcholinerelease. Efaroxan affected acetylcholine release differently depending on concentration. Nicotinic receptor blockade atten-uated the effect of all ligands. All ligands showed poor binding affinity for muscarinic receptors. On the other hand, allligands possessed affinity for nicotinic receptors. Clonidine and yohimbine binding was best fit to a one site binding curveand rilmenidine and efaroxan to a two site binding curve. The present study demonstrates that the tested a2-adrenergicreceptor ligands affect intraspinal acetylcholine release in the rat evoked by nicotinic receptor mechanisms in vivo, andthat they possess binding affinity to nicotinic receptors in vitro. The binding of a2-adrenergic receptor ligands to nicotinicreceptors might affect the intraspinal release of acetylcholine.

  • 7.
    Abelson, Klas
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience, Comparative Medicine.
    Kommalage, Mahinda
    Höglund, Urban
    Spinal cholinergic involvement after treatment with aspirin and paracetamol in rats2004In: Neuroscience Letters, ISSN 0304-3940, Vol. 368, no 1, p. 116-120Article in journal (Refereed)
  • 8.
    Adelholt, Denise
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    The Effects of Cell Culture Medium and Supplements on the Differentiation of Boundary Cap Neural Crest Stem Cells2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Boundary cap neural crest stem cells (bNCSCs) are multipotent cells that form a barrier between CNS and PNS, playing an important role in ingrowth of neurites into the spinal cord during development. Because of the stemness and multipotency of bNCSCs, they self-renew and can be used directly for transplantation or as a source of matured neural cells. It is important that cells used for cell therapy differentiate and develop into the mature cells that the recipient needs. To ensure this, cells are guided towards specific cell fates, and one way of doing this is with medium supplements. The purpose of this study was to analyze the effects of three different media with supplements on the differentiation of bNCSCs. Two cell lineages of bNCSCs expressing green- and red fluorescent protein were treated with different media for differentiation. The effects of the media supplements neurotrophic glial cell line-derived neurotrophic factor (GDNF), cilinary neurotrophic factor (CTNF) and fetal bovine serum (FBS) were compared, with one medium containing no additional factors. It was found that when GDNF and CTNF are supplemented in the differentiation media, bNCSCs are guided towards astrocytes. Interestingly, the medium containing no additional factors gave rise to an even amount of neurons and astrocytes. FBS had an inhibitory effect on overall differentiation of bNCSCs, giving rise to the smallest amount of neurons and astrocytes. The bNCSCs are promising for cell therapy, as their differentiation can be guided with the use of medium supplements.

  • 9. Adinda, Mathia
    Nutrition supplements when undergoing orthopedic surgery2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Malnutrition is prevalent in elderly populations with orthopedic disabilities, which is especially critical during surgery when the body is under much stress. It is important that these patients are well nourished to be able to cope when mechanisms such as immune system are activated. Nutrition is also important after surgery when the body is healing and sometimes struggling against different complications as infections. The aim of this study was to evaluate if nutrition supplements decreases the time needed for rehabilitation and improve the outcome after orthopedic surgeries. This was performed by analyzing biomarkers involved in wound healing. The study population comprised of 100 surgical patients at the age of 50 or older. The participant where divided into two groups, one test group that received nutrition supplements and one control group who did not receive any extra nutrition. Sandwich ELISA was used to measure myostatin, cathepsin S and cathepsin B concentrations in patient serum before and after surgery. There were no significant difference between the control group and the test group for any of the three biomarkers. The conclusion is that nutrition supplement does not decrease the rehabilitation time and outcome according to the results in this study.

  • 10.
    Adrian-Kalchhauser, Irene
    et al.
    Univ Basel, Program Man Soc Environm, Dept Environm Sci, Vesalgasse 1, CH-4051 Basel, Switzerland..
    Svensson, Ola
    Univ Gothenburg, Dept Biol & Environm Sci, Medicinaregatan 18A, S-41390 Gothenburg, Sweden.;Univ Gothenburg, Linnaeus Ctr Marine Evolutionary Biol, POB 46040530, Gothenburg, Sweden..
    Kutschera, Verena E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Rosenblad, Magnus Alm
    Univ Gothenburg, Linnaeus Ctr Marine Evolutionary Biol, POB 46040530, Gothenburg, Sweden.;Univ Gothenburg, Dept Marine Sci, NBIS Bioinformat Infrastruct Life Sci, Medicinaregatan 9C, S-41390 Gothenburg, Sweden..
    Pippel, Martin
    Heidelberg Inst Theoret Studies, Schloss Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany..
    Winkler, Sylke
    Max Planck Inst Mol Cell Biol & Genet, Pfotenhauerstr 108, D-01307 Dresden, Germany..
    Schloissnig, Siegfried
    Heidelberg Inst Theoret Studies, Schloss Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany..
    Blomberg, Anders
    Univ Gothenburg, Linnaeus Ctr Marine Evolutionary Biol, POB 46040530, Gothenburg, Sweden.;Univ Gothenburg, Dept Marine Sci, Medicinaregatan 9C, S-41390 Gothenburg, Sweden..
    Burkhardt-Holm, Patricia
    Univ Basel, Program Man Soc Environm, Dept Environm Sci, Vesalgasse 1, CH-4051 Basel, Switzerland.;Univ Alberta, Dept Biol Sci, 11455 Saskatchewan Dr, Edmonton, AB, Canada..
    The mitochondrial genome sequences of the round goby and the sand goby reveal patterns of recent evolution in gobiid fish2017In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 18, article id 177Article in journal (Refereed)
    Abstract [en]

    Background: Vertebrate mitochondrial genomes are optimized for fast replication and low cost of RNA expression. Accordingly, they are devoid of introns, are transcribed as polycistrons and contain very little intergenic sequences. Usually, vertebrate mitochondrial genomes measure between 16.5 and 17 kilobases ( kb). Results: During genome sequencing projects for two novel vertebrate models, the invasive round goby and the sand goby, we found that the sand goby genome is exceptionally small (16.4 kb), while the mitochondrial genome of the round goby is much larger than expected for a vertebrate. It is 19 kb in size and is thus one of the largest fish and even vertebrate mitochondrial genomes known to date. The expansion is attributable to a sequence insertion downstream of the putative transcriptional start site. This insertion carries traces of repeats from the control region, but is mostly novel. To get more information about this phenomenon, we gathered all available mitochondrial genomes of Gobiidae and of nine gobioid species, performed phylogenetic analyses, analysed gene arrangements, and compared gobiid mitochondrial genome sizes, ecological information and other species characteristics with respect to the mitochondrial phylogeny. This allowed us amongst others to identify a unique arrangement of tRNAs among Ponto-Caspian gobies. Conclusions: Our results indicate that the round goby mitochondrial genome may contain novel features. Since mitochondrial genome organisation is tightly linked to energy metabolism, these features may be linked to its invasion success. Also, the unique tRNA arrangement among Ponto- Caspian gobies may be helpful in studying the evolution of this highly adaptive and invasive species group. Finally, we find that the phylogeny of gobiids can be further refined by the use of longer stretches of linked DNA sequence.

  • 11.
    Ajalloueian, F.
    et al.
    Isfahan Univ Technol, Dept Text Engn, Ctr Excellence Appl Nanotechnol, Esfahan, Iran..
    Fransson, M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Tavanai, H.
    Isfahan Univ Technol, Dept Text Engn, Ctr Excellence Appl Nanotechnol, Esfahan, Iran..
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Magnusson, Peetra
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology. Uppsala Univ, Dept Immunol Genet & Pathol IGP, Uppsala, Sweden..
    Arpanaei, A.
    Natl Inst Genet Engn & Biotechnol, Dept Ind & Environm Biotechnol, Tehran, Iran..
    Comparing PLGA and PLGA/Chitosan Nanofibers Seeded by Msc: A Cell-scaffold Interaction Study2015In: Tissue Engineering. Part A, ISSN 1937-3341, E-ISSN 1937-335X, Vol. 21, p. S406-S407Article in journal (Other academic)
  • 12.
    Ajalloueian, F.
    et al.
    Tech Univ Denmark, Copenhagen, Denmark..
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Fossum, M.
    Karolinska Inst, Stockholm, Sweden..
    Chronakis, I. S.
    Tech Univ Denmark, Copenhagen, Denmark..
    Integrated Micro/Nanofibrous PLGA-Collagen Scaffold: an Optimized Method for Plastic Compression of Collagen into PLGA Microfibers2015In: Tissue Engineering. Part A, ISSN 1937-3341, E-ISSN 1937-335X, Vol. 21, p. S347-S347Article in journal (Other academic)
  • 13.
    Ajalloueian, Fatemeh
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Fransson, Moa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Tavanai, Hossein
    Massuni, Mohammad
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    LeBlanc, Katarina
    Arpanaei, Ayyoob
    Magnusson, Peetra
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Investigation of Human Mesenchymal Stromal Cells Cultured on PLGA orPLGA/Chitosan Electrospun Nanofibers2015In: Journal of Bioprocessing & Biotechniques, ISSN 2155-9821, Vol. 5, no 6, article id 230Article in journal (Refereed)
    Abstract [en]

    We compared the viability, proliferation, and differentiation of human Mesenchymal Stromal Cells (MSC)after culture on poly(lactic-co-glycolic acid) (PLGA) and PLGA/chitosan (PLGA/CH) hybrid scaffolds. We appliedconventional and emulsion electrospinning techniques, respectively, for the fabrication of the PLGA and PLGA/CH scaffolds. Electrospinning under optimum conditions resulted in an average fiber diameter of 166 ± 33 nmfor the PLGA/CH and 680 ± 175 nm for the PLGA scaffold. The difference between the tensile strength of thePLGA and PLGA/CH nanofibers was not significant, but PLGA/CH showed a significantly lower tensile modulusand elongation at break. However, it should be noted that the extensibility of the PLGA/CH was higher than thatof the nanofibrous scaffolds of pure chitosan. As expected, a higher degree of hydrophilicity was seen with PLGA/CH, as compared to PLGA alone. The biocompatibility of the PLGA and PLGA/CH scaffolds was compared usingMTS assay as well as analysis by scanning electron microscopy and confocal microscopy. The results showed thatboth scaffold types supported the viability and proliferation of human MSC, with significantly higher rates on PLGA/CH nanofibers. Nonetheless, an analysis of gene expression of MSC grown on either PLGA or PLGA/CH showed asimilar differentiation pattern towards bone, nerve and adipose tissues.

  • 14.
    Ajalloueian, Fatemeh
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Zeiai, Said
    Fossum, Magdalena
    Hilborn, Jöns G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Constructs of electrospun PLGA, compressed collagen and minced urothelium for minimally manipulated autologous bladder tissue expansion2014In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 35, no 22, p. 5741-5748Article in journal (Refereed)
    Abstract [en]

    Bladder regeneration based on minced bladder mucosa in vivo expansion is an alternative to in vitro culturing of urothelial cells. Here, we present the design of a hybrid, electrospun poly(lactic-co-glycolide) (PLGA) - plastically compressed (PC) collagen scaffold that could allow in vivo bladder mucosa expansion. Optimisation of electrospinning was performed in order to obtain increased pore sizes and porosity to consolidate the construct and to support neovascularisation and tissue ingrowth. Tensile tests showed an increase in average tensile strength from 0.6 MPa for PC collagen to 3.57 MPa for the hybrid construct. The optimised PLGA support scaffold was placed between two collagen gels, and the minced tissue was distributed either on top or both on top and inside the construct prior to PC; this was then cultured for up to four weeks. Morphology, histology and SEM demonstrated that the construct maintained its integrity throughout cell culture. Cells from minced tissue migrated, expanded and re-organised to a confluent cell layer on the top of the construct after two weeks and formed a multilayered urothelium after four weeks. Cell morphology and phenotype was typical for urothelial mucosa during tissue culture. (C) 2014 Elsevier Ltd. All rights reserved.

  • 15.
    Ajaxon, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Can Bone Void Fillers Carry Load?: Behaviour of Calcium Phosphate Cements Under Different Loading Scenarios2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Calcium phosphate cements (CPCs) are used as bone void fillers and as complements to hardware in fracture fixation. The aim of this thesis was to investigate the possibilities and limitations of the CPCs’ mechanical properties, and find out if these ceramic bone cements can carry application-specific loads, alone or as part of a construct. Recently developed experimental brushite and apatite cements were found to have a significantly higher strength in compression, tension and flexion compared to the commercially available CPCs chronOS™ Inject and Norian® SRS®. By using a high-resolution measurement technique the elastic moduli of the CPCs were determined and found to be at least twice as high compared to earlier measurements, and closer to cortical bone than trabecular bone. Using the same method, Poisson's ratio for pure CPCs was determined for the first time. A non-destructive porosity measurement method for wet brushite cements was developed, and subsequently used to study the porosity increase during in vitro degradation. The compressive strength of the experimental brushite cement was still higher than that of trabecular bone after 25 weeks of degradation, showing that the cement can carry high loads over a time span sufficiently long for a fracture to heal. This thesis also presents the first ever fatigue results for acidic CPCs, and confirms the importance of testing the materials under cyclic loading as the cements may fail at stress levels much lower than the material’s quasi-static compressive strength. A decrease in fatigue life was found for brushite cements containing higher amounts of monetite. Increasing porosity and testing in a physiological buffer solution (PBS), rather than air, also decreased the fatigue life. However, the experimental brushite cement had a high probability of surviving loads found in the spine when tested in PBS, which has previously never been accomplished for acidic CPCs. In conclusion, available brushite cements may be able to carry the load alone in scenarios where the cortical shell is intact, the loading is mainly compressive, and the expected maximum stress is below 10 MPa. Under such circumstances this CPC may be the preferred choice over less biocompatible and non-degradable materials.

    List of papers
    1. Mechanical Properties of Brushite Calcium Phosphate Cements
    Open this publication in new window or tab >>Mechanical Properties of Brushite Calcium Phosphate Cements
    2017 (English)In: The World Scientific Encyclopedia of Nanomedicine and Bioengineering II: Bioimplants, Regenerative Medicine, and Nano-Cancer Diagnosis and Phototherapy: Volume 3: Design of Bioactive Materials for Bone Repair and Regeneration / [ed] Shi, D., Singapore: World Scientific Pte Ltd. , 2017Chapter in book (Refereed)
    Place, publisher, year, edition, pages
    Singapore: World Scientific Pte Ltd., 2017
    National Category
    Biomaterials Science Ceramics Medical Materials
    Identifiers
    urn:nbn:se:uu:diva-316712 (URN)978-981-4667-58-6 (ISBN)
    Funder
    Swedish Research Council, GA 621-2011-6258
    Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-03-22
    2. Compressive, diametral tensile and biaxial flexural strength of cutting-edge calcium phosphate cements
    Open this publication in new window or tab >>Compressive, diametral tensile and biaxial flexural strength of cutting-edge calcium phosphate cements
    Show others...
    2016 (English)In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 60, p. 617-627Article in journal (Refereed) Published
    Abstract [en]

    Calcium phosphate cements (CPCs) are widely used in bone repair. Currently there are two main types of CPCs, brushite and apatite. The aim of this project was to evaluate the mechanical properties of particularly promising experimental brushite and apatite formulations in comparison to commercially available brushite- and apatite-based cements (chronOS Inject and Norian® SRS®, respectively), and in particular evaluate the diametral tensile strength and biaxial flexural strength of these cements in both wet and dry conditions for the first time. The cements׳ porosity and their compressive, diametral tensile and biaxial flexural strength were tested in wet (or moist) and dry conditions. The surface morphology was characterized by scanning electron microscopy. Phase composition was assessed with X-ray diffraction. It was found that the novel experimental cements showed better mechanical properties than the commercially available cements, in all loading scenarios. The highest compressive strength (57.2±6.5 MPa before drying and 69.5±6.0 MPa after drying) was found for the experimental brushite cement. This cement also showed the highest wet diametral tensile strength (10.0±0.8 MPa) and wet biaxial flexural strength (30.7±1.8 MPa). It was also the cement that presented the lowest porosity (approx. 12%). The influence of water content was found to depend on cement type, with some cements showing higher mechanical properties after drying and some no difference after drying.

    Keywords
    Calcium phosphate cement; Brushite; Apatite; Compressive strength; Tensile strength; Flexural strength
    National Category
    Ceramics
    Identifiers
    urn:nbn:se:uu:diva-284218 (URN)10.1016/j.jmbbm.2016.03.028 (DOI)000378969100055 ()27082025 (PubMedID)
    Funder
    The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IG2011-2047Swedish Research Council, 621-2011-6258
    Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2018-08-10Bibliographically approved
    3. Elastic properties and strain-to-crack-initation of calcium phosphate bone cements: Revelations of a high-resolution measurement technique
    Open this publication in new window or tab >>Elastic properties and strain-to-crack-initation of calcium phosphate bone cements: Revelations of a high-resolution measurement technique
    Show others...
    2017 (English)In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 74, p. 428-437Article in journal (Refereed) Published
    Abstract [en]

    Calcium phosphate cements (CPCs) should ideally have mechanical properties similar to those of the bone tissue the material is used to replace or repair. Usually, the compressive strength of the CPCs is reported and, more rarely, the elastic modulus. Conversely, scarce or no data are available on Poisson's ratio and strain-to-crack-initiation. This is unfortunate, as data on the elastic response is key to, e.g., numerical model accuracy. In this study, the compressive behaviour of brushite, monetite and apatite cements was fully characterised. Measurement of the surface strains was done using a digital image correlation (DIC) technique, and compared to results obtained with the commonly used built-in displacement measurement of the materials testers. The collected data showed that the use of fixed compression platens, as opposed to spherically seated ones, may in some cases underestimate the compressive strength by up to 40%. Also, the built-in measurements may underestimate the elastic modulus by up to 62% as compared to DIC measurements. Using DIC, the brushite cement was found to be much stiffer (24.3 ± 2.3 GPa) than the apatite (13.5 ± 1.6 GPa) and monetite (7.1 ± 1.0 GPa) cements, and elastic moduli were inversely related to the porosity of the materials. Poisson's ratio was determined to be 0.26 ± 0.02 for brushite, 0.21 ± 0.02 for apatite and 0.20 ± 0.03 for monetite. All investigated CPCs showed low strain-to-crack-initiation (0.17–0.19%). In summary, the elastic modulus of CPCs is substantially higher than previously reported and it is concluded that an accurate procedure is a prerequisite in order to properly compare the mechanical properties of different CPC formulations. It is recommended to use spherically seated platens and measuring the strain at a relevant resolution and on the specimen surface.

    National Category
    Ceramics Medical Materials Biomaterials Science
    Identifiers
    urn:nbn:se:uu:diva-316718 (URN)10.1016/j.jmbbm.2017.06.023 (DOI)000410253500046 ()28735216 (PubMedID)
    Funder
    The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IG2011-2047Swedish Research Council, 621-2011-6258
    Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-12-04Bibliographically approved
    4. Evaluation of a porosity measurement method for wet calcium phosphate cements
    Open this publication in new window or tab >>Evaluation of a porosity measurement method for wet calcium phosphate cements
    Show others...
    2015 (English)In: Journal of biomaterials applications, ISSN 0885-3282, E-ISSN 1530-8022, Vol. 30, no 5, p. 526-536Article in journal (Refereed) Published
    Abstract [en]

    The porosity of a calcium phosphate cement is a key parameter as it affects several important properties of the cement. However, a successful, non-destructive porosity measurement method that does not include drying has not yet been reported for calcium phosphate cements. The aim of this study was to evaluate isopropanol solvent exchange as such a method. Two different types of calcium phosphate cements were used, one basic (hydroxyapatite) and one acidic (brushite). The cements were allowed to set in an aqueous environment and then immersed in isopropanol and stored under three different conditions: at room temperature, at room temperature under vacuum (300 mbar) or at 37􏰀C. The specimen mass was monitored regularly. Solvent exchange took much longer time to reach steady state in hydroxyapatite cements compared to brushite cements, 350 and 18 h, respectively. Furthermore, the immersion affected the quasi-static compressive strength of the hydroxyapatite cements. However, the strength and phase composition of the brushite cements were not affected by isopropanol immersion, suggesting that isopropanol solvent exchange can be used for brushite calcium phosphate cements. The main advantages with this method are that it is non-destructive, fast, easy and the porosity can be evaluated while the cements remain wet, allowing for further analysis on the same specimen. 

    Place, publisher, year, edition, pages
    Sage Publications, 2015
    Keywords
    Calcium phosphate, bone cement, porosity, solvent exchange, brushite, hydroxyapatite
    National Category
    Ceramics Biomaterials Science Medical Materials
    Research subject
    Engineering Science with specialization in Materials Science
    Identifiers
    urn:nbn:se:uu:diva-258636 (URN)10.1177/0885328215594293 (DOI)000367743900003 ()26163278 (PubMedID)
    Funder
    The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IG2011-2047Swedish Research Council, 621-2011-6258
    Available from: 2015-07-17 Created: 2015-07-17 Last updated: 2017-12-04Bibliographically approved
    5. Long-term in vitro degradation of a high-strength brushite cement in water, PBS, and serum solution
    Open this publication in new window or tab >>Long-term in vitro degradation of a high-strength brushite cement in water, PBS, and serum solution
    2015 (English)In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 575079Article in journal (Refereed) Published
    Abstract [en]

    Bone loss and fractures may call for the use of bone substituting materials, such as calcium phosphate cements (CPCs). CPCs can be degradable, and, to determine their limitations in terms of applications, their mechanical as well as chemical properties need to be evaluated over longer periods of time, under physiological conditions. However, there is lack of data on how the in vitro degradation affects high-strength brushite CPCs over longer periods of time, that is, longer than it takes for a bone fracture to heal. This study aimed at evaluating the long-term in vitro degradation properties of a high-strength brushite CPC in three different solutions: water, phosphate buffered saline, and a serum solution. Microcomputed tomography was used to evaluate the degradation nondestructively, complemented with gravimetric analysis. The compressive strength, chemical composition, and microstructure were also evaluated. Major changes from 10 weeks onwards were seen, in terms of formation of a porous outer layer of octacalcium phosphate on the specimens with a concomitant change in phase composition, increased porosity, decrease in object volume, and mechanical properties. This study illustrates the importance of long-term evaluation of similar cement compositions to be able to predict the material’s physical changes over a relevant time frame. 

    Place, publisher, year, edition, pages
    Hindawi Publishing Corporation, 2015
    Keywords
    Calcium phosphate, brushite, bone cement, degradation, in vitro, solvent exchange, compressive strength, micro-CT, porosity
    National Category
    Ceramics Bio Materials Biomaterials Science Medical Materials
    Research subject
    Engineering Science with specialization in Materials Science
    Identifiers
    urn:nbn:se:uu:diva-265319 (URN)10.1155/2015/575079 (DOI)000364660000001 ()
    Funder
    The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IG2011-207Swedish Research Council, 621-2011-6258
    Available from: 2015-10-27 Created: 2015-10-27 Last updated: 2017-12-01Bibliographically approved
    6. Compressive fatigue properties of an acidic calcium phosphate cement—effect of phase composition
    Open this publication in new window or tab >>Compressive fatigue properties of an acidic calcium phosphate cement—effect of phase composition
    2017 (English)In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 28, no 3, article id 41Article in journal (Refereed) Published
    Abstract [en]

    Calcium phosphate cements (CPCs) are synthetic bone grafting materials that can be used in fracture stabilization and to fill bone voids after, e.g., bone tumour excision. Currently there are several calcium phosphate-based formulations available, but their use is partly limited by a lack of knowledge of their mechanical properties, in particular their resistance to mechanical loading over longer periods of time. Furthermore, depending on, e.g., setting conditions, the end product of acidic CPCs may be mainly brushite or monetite, which have been found to behave differently under quasi-static loading. The objectives of this study were to evaluate the compressive fatigue properties of acidic CPCs, as well as the effect of phase composition on these properties. Hence, brushite cements stored for different lengths of time and with different amounts of monetite were investigated under quasi-static and dynamic compression. Both storage and brushite-to-monetite phase transformation was found to have a pronounced effect both on quasi-static compressive strength and fatigue performance of the cements, whereby a substantial phase transformation gave rise to a lower mechanical resistance. The brushite cements investigated in this study had the potential to survive 5 million cycles at a maximum compressive stress of 13 MPa. Given the limited amount of published data on fatigue properties of CPCs, this study provides an important insight into the compressive fatigue behaviour of such materials. 

    Keywords
    Bone cement, brushite, monetite, fatigue, mechanical properties
    National Category
    Ceramics Medical Materials Biomaterials Science
    Research subject
    Engineering Science with specialization in Materials Science
    Identifiers
    urn:nbn:se:uu:diva-314237 (URN)10.1007/s10856-017-5851-5 (DOI)000394242700006 ()28144853 (PubMedID)
    Funder
    Swedish Research Council, 621-2011-6258
    Available from: 2017-02-03 Created: 2017-01-31 Last updated: 2017-11-29Bibliographically approved
    7. Compressive fatigue properties of a high-strength, degradable calcium phosphate bone cement – influence of porosity and environment
    Open this publication in new window or tab >>Compressive fatigue properties of a high-strength, degradable calcium phosphate bone cement – influence of porosity and environment
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ceramics Medical Materials Biomaterials Science
    Identifiers
    urn:nbn:se:uu:diva-316717 (URN)
    Funder
    Swedish Research Council, 621-2011-6258
    Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-03-22
  • 16.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Acciaioli, Alice
    Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica.
    Lionello, Giacomo
    Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica.
    Ginebra, Maria-Pau
    Biomaterials, Biomechanics and Tissue Engineering Group, Dept. of Materials Science and Metallurgy, Technical University of Catalonia (UPC).
    Öhman, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Baleani, Massimilliano
    Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Elastic properties and strain-to-crack-initation of calcium phosphate bone cements: Revelations of a high-resolution measurement technique2017In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 74, p. 428-437Article in journal (Refereed)
    Abstract [en]

    Calcium phosphate cements (CPCs) should ideally have mechanical properties similar to those of the bone tissue the material is used to replace or repair. Usually, the compressive strength of the CPCs is reported and, more rarely, the elastic modulus. Conversely, scarce or no data are available on Poisson's ratio and strain-to-crack-initiation. This is unfortunate, as data on the elastic response is key to, e.g., numerical model accuracy. In this study, the compressive behaviour of brushite, monetite and apatite cements was fully characterised. Measurement of the surface strains was done using a digital image correlation (DIC) technique, and compared to results obtained with the commonly used built-in displacement measurement of the materials testers. The collected data showed that the use of fixed compression platens, as opposed to spherically seated ones, may in some cases underestimate the compressive strength by up to 40%. Also, the built-in measurements may underestimate the elastic modulus by up to 62% as compared to DIC measurements. Using DIC, the brushite cement was found to be much stiffer (24.3 ± 2.3 GPa) than the apatite (13.5 ± 1.6 GPa) and monetite (7.1 ± 1.0 GPa) cements, and elastic moduli were inversely related to the porosity of the materials. Poisson's ratio was determined to be 0.26 ± 0.02 for brushite, 0.21 ± 0.02 for apatite and 0.20 ± 0.03 for monetite. All investigated CPCs showed low strain-to-crack-initiation (0.17–0.19%). In summary, the elastic modulus of CPCs is substantially higher than previously reported and it is concluded that an accurate procedure is a prerequisite in order to properly compare the mechanical properties of different CPC formulations. It is recommended to use spherically seated platens and measuring the strain at a relevant resolution and on the specimen surface.

  • 17.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Acciaioli, Alice
    Lionello, Giacomo
    Ginebra, Maria-Pau
    Öhman, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Baleani, Massimiliano
    Compressive strength increase of calcium phosphate bone cements is accompanied by a stiffness increase2016Conference paper (Other academic)
  • 18.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Holmberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Öhman Mägi, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    The influence of porosity on the fatigue properties of brushite cement2016In: Biomaterials for tissue engineering models, 2016Conference paper (Other academic)
  • 19.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Holmberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Öhman-Mägi, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Compressive fatigue properties of a high-strength, degradable calcium phosphate bone cement – influence of porosity and environmentManuscript (preprint) (Other academic)
  • 20.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Maazouz, Yassine
    Ginebra, Maria-Pau
    Öhman, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Evaluation of a porosity measurement method for wet calcium phosphate cements2015In: Journal of biomaterials applications, ISSN 0885-3282, E-ISSN 1530-8022, Vol. 30, no 5, p. 526-536Article in journal (Refereed)
    Abstract [en]

    The porosity of a calcium phosphate cement is a key parameter as it affects several important properties of the cement. However, a successful, non-destructive porosity measurement method that does not include drying has not yet been reported for calcium phosphate cements. The aim of this study was to evaluate isopropanol solvent exchange as such a method. Two different types of calcium phosphate cements were used, one basic (hydroxyapatite) and one acidic (brushite). The cements were allowed to set in an aqueous environment and then immersed in isopropanol and stored under three different conditions: at room temperature, at room temperature under vacuum (300 mbar) or at 37􏰀C. The specimen mass was monitored regularly. Solvent exchange took much longer time to reach steady state in hydroxyapatite cements compared to brushite cements, 350 and 18 h, respectively. Furthermore, the immersion affected the quasi-static compressive strength of the hydroxyapatite cements. However, the strength and phase composition of the brushite cements were not affected by isopropanol immersion, suggesting that isopropanol solvent exchange can be used for brushite calcium phosphate cements. The main advantages with this method are that it is non-destructive, fast, easy and the porosity can be evaluated while the cements remain wet, allowing for further analysis on the same specimen. 

  • 21.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mechanical Properties of Brushite Calcium Phosphate Cements2017In: The World Scientific Encyclopedia of Nanomedicine and Bioengineering II: Bioimplants, Regenerative Medicine, and Nano-Cancer Diagnosis and Phototherapy: Volume 3: Design of Bioactive Materials for Bone Repair and Regeneration / [ed] Shi, D., Singapore: World Scientific Pte Ltd. , 2017Chapter in book (Refereed)
  • 22.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Öhman, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Long-term in vitro degradation of a high-strength brushite cement in water, PBS, and serum solution2015In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 575079Article in journal (Refereed)
    Abstract [en]

    Bone loss and fractures may call for the use of bone substituting materials, such as calcium phosphate cements (CPCs). CPCs can be degradable, and, to determine their limitations in terms of applications, their mechanical as well as chemical properties need to be evaluated over longer periods of time, under physiological conditions. However, there is lack of data on how the in vitro degradation affects high-strength brushite CPCs over longer periods of time, that is, longer than it takes for a bone fracture to heal. This study aimed at evaluating the long-term in vitro degradation properties of a high-strength brushite CPC in three different solutions: water, phosphate buffered saline, and a serum solution. Microcomputed tomography was used to evaluate the degradation nondestructively, complemented with gravimetric analysis. The compressive strength, chemical composition, and microstructure were also evaluated. Major changes from 10 weeks onwards were seen, in terms of formation of a porous outer layer of octacalcium phosphate on the specimens with a concomitant change in phase composition, increased porosity, decrease in object volume, and mechanical properties. This study illustrates the importance of long-term evaluation of similar cement compositions to be able to predict the material’s physical changes over a relevant time frame. 

  • 23.
    Ajaxon, Ingrid
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Öhman Mägi, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Compressive fatigue properties of an acidic calcium phosphate cement—effect of phase composition2017In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 28, no 3, article id 41Article in journal (Refereed)
    Abstract [en]

    Calcium phosphate cements (CPCs) are synthetic bone grafting materials that can be used in fracture stabilization and to fill bone voids after, e.g., bone tumour excision. Currently there are several calcium phosphate-based formulations available, but their use is partly limited by a lack of knowledge of their mechanical properties, in particular their resistance to mechanical loading over longer periods of time. Furthermore, depending on, e.g., setting conditions, the end product of acidic CPCs may be mainly brushite or monetite, which have been found to behave differently under quasi-static loading. The objectives of this study were to evaluate the compressive fatigue properties of acidic CPCs, as well as the effect of phase composition on these properties. Hence, brushite cements stored for different lengths of time and with different amounts of monetite were investigated under quasi-static and dynamic compression. Both storage and brushite-to-monetite phase transformation was found to have a pronounced effect both on quasi-static compressive strength and fatigue performance of the cements, whereby a substantial phase transformation gave rise to a lower mechanical resistance. The brushite cements investigated in this study had the potential to survive 5 million cycles at a maximum compressive stress of 13 MPa. Given the limited amount of published data on fatigue properties of CPCs, this study provides an important insight into the compressive fatigue behaviour of such materials. 

  • 24.
    Akgun, Kocere Kurdé
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Evaluation of Different Extraction- and Analysis Methods for Calprotectin in Feces2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background Calprotectin is a protein expressed in the cytoplasm inside the neutrophile granulocytes. During inflammatory bowel disease (IBD), the neutrophile granulocytes are involved in a complex interaction at the inflammatory area where they die and release their content into the intestinal lumen. Therefore, calprotectin in stool is a suitable marker for diagnosis and measurement of the disease-activity in patients with IBD. The most commonly used method to detect calprotectin in stool is ELISA, but the process of manual preparation of stool samples is time-consuming.

    Aim The objective of the study was to evaluate an extraction method that could replace manual preparation of fecal samples and to compare different methods for measuring Calprotectin in stool using two ELISA-methods from two manufacturers and one rapidtest.

    Methods For extraction of calprotectin from stool samples we used sample collector tubes from Epitope Diagnostics and fecal preparation kits from Roche. Two different ELISA-kits for measuring calprotectin concentration in stool were compared. Measurements of calprotectin with rapid-test from Epitope Diagnostics were also performed and were compared with the two ELISA kits.

    Results The results indicate a poor correlation between two extraction methods with Sample Collector Tube and Roche preparation kit. The comparison between the two ELISA-kits showed poor correlation. Evaluation of rapid test showed 33% false negative results with a cut-off value at 50 mg/kg.

    Conclusion Evaluation of products from Epitope Diagnostics showed poor correlation with the Bühlmann ELISA and an unreliable rapid test. Therefore, none of evaluated products from Epitope Diagnostics is accurate enough to be used for clinical diagnosis in the laboratory.

  • 25. Akoachere, Monique
    et al.
    Iozef, Rimma
    Rahlfs, Stefan
    Deponte, Marcel
    Mannervik, Bengt
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry. Department of Biochemistry and Organic Chemistry, Biochemistry.
    Creighton, Donald J
    Schirmer, Heiner
    Becker, Katja
    Characterization of the glyoxalases of the malarial parasite Plasmodium falciparum and comparison with their human counterparts.2005In: Biol Chem, ISSN 1431-6730, Vol. 386, no 1, p. 41-52Article in journal (Refereed)
    Abstract [en]

    The glyoxalase system consisting of glyoxalase I (GloI) and glyoxalase II (GloII) constitutes a glutathione-dependent intracellular pathway converting toxic 2-oxoaldehydes, such as methylglyoxal, to the corresponding 2-hydroxyacids. Here we describe a complete glyoxalase system in the malarial parasite Plasmodium falciparum. The biochemical, kinetic and structural properties of cytosolic GloI (cGloI) and two GloIIs (cytosolic GloII named cGloII, and tGloII preceded by a targeting sequence) were directly compared with the respective isofunctional host enzymes. cGloI and cGloII exhibit lower K(m) values and higher catalytic efficiencies (k(cat)/K(m) ) than the human counterparts, pointing to the importance of the system in malarial parasites. A Tyr185Phe mutant of cGloII shows a 2.5-fold increase in K(m) , proving the contribution of Tyr185 to substrate binding. Molecular models suggest very similar active sites/metal binding sites of parasite and host cell enzymes. However, a fourth protein, which has highest similarities to GloI, was found to be unique for malarial parasites; it is likely to act in the apicoplast, and has as yet undefined substrate specificity. Various S-(N-hydroxy-N-arylcarbamoyl)glutathiones tested as P. falciparum Glo inhibitors were active in the lower nanomolar range. The Glo system of Plasmodium will be further evaluated as a target for the development of antimalarial drugs.

  • 26.
    Akula, Srinivas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Mohammadamin, Sayran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Hellman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Chemical Biology.
    Fc Receptors for Immunoglobulins and Their Appearance during Vertebrate Evolution2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 5, p. e96903-Article in journal (Refereed)
    Abstract [en]

    Receptors interacting with the constant domain of immunoglobulins (Igs) have a number of important functions in vertebrates. They facilitate phagocytosis by opsonization, are key components in antibody-dependent cellular cytotoxicity as well as activating cells to release granules. In mammals, four major types of classical Fc receptors (FcRs) for IgG have been identified, one high-affinity receptor for IgE, one for both IgM and IgA, one for IgM and one for IgA. All of these receptors are related in structure and all of them, except the IgA receptor, are found in primates on chromosome 1, indicating that they originate from a common ancestor by successive gene duplications. The number of Ig isotypes has increased gradually during vertebrate evolution and this increase has likely been accompanied by a similar increase in isotype-specific receptors. To test this hypothesis we have performed a detailed bioinformatics analysis of a panel of vertebrate genomes. The first components to appear are the poly-Ig receptors (PIGRs), receptors similar to the classic FcRs in mammals, so called FcRL receptors, and the FcR gamma chain. These molecules are not found in cartilagous fish and may first appear within bony fishes, indicating a major step in Fc receptor evolution at the appearance of bony fish. In contrast, the receptor for IgA is only found in placental mammals, indicating a relatively late appearance. The IgM and IgA/M receptors are first observed in the monotremes, exemplified by the platypus, indicating an appearance during early mammalian evolution. Clearly identifiable classical receptors for IgG and IgE are found only in marsupials and placental mammals, but closely related receptors are found in the platypus, indicating a second major step in Fc receptor evolution during early mammalian evolution, involving the appearance of classical IgG and IgE receptors from FcRL molecules and IgM and IgA/M receptors from PIGR.

  • 27.
    Akula, Srinivas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Chemical Biology.
    Thorpe, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Chemical Biology.
    Boinapally, Vamsi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Chemical Biology.
    Hellman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Chemical Biology.
    Granule Associated Serine Proteases of Hematopoietic Cells - An Analysis of Their Appearance and Diversification during Vertebrate Evolution2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 11, article id e0143091Article in journal (Refereed)
    Abstract [en]

    Serine proteases are among the most abundant granule constituents of several hematopoietic cell lineages including mast cells, neutrophils, cytotoxic T cells and NK cells. These proteases are stored in their active form in the cytoplasmic granules and in mammals are encoded from four different chromosomal loci: the chymase locus, the met-ase locus, the T cell tryptase and the mast cell tryptase locus. In order to study their appearance during vertebrate evolution we have performed a bioinformatic analysis of related genes and gene loci from a large panel of metazoan animals from sea urchins to placental mammals for three of these loci: the chymase, met-ase and granzyme A/K loci. Genes related to mammalian granzymes A and K were the most well conserved and could be traced as far back to cartilaginous fish. Here, the granzyme A and K genes were found in essentially the same chromosomal location from sharks to humans. However in sharks, no genes clearly identifiable as members of the chymase or met-ase loci were found. A selection of these genes seemed to appear with bony fish, but sometimes in other loci. Genes related to mammalian met-ase locus genes were found in bony fish. Here, the most well conserved member was complement factor D. However, genes distantly related to the neutrophil proteases were also identified in this locus in several bony fish species, indicating that this locus is also old and appeared at the base of bony fish. In fish, a few of the chymase locus-related genes were found in a locus with bordering genes other than the mammalian chymase locus and some were found in the fish met-ase locus. This indicates that a convergent evolution rather than divergent evolution has resulted in chymase locus-related genes in bony fish.

  • 28.
    Albeer, Merna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Evaluation of ELISA and rapid test for the analysis of fecal Calprotectin2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ABSTRACT

    Background Calprotectin is a protein found in the cytoplasm of neutrophile granulocytes. In the course of inflammatory bowel disease (IBD), calprotectin is released during chronic inflammation in the gut. Activation of neutrophils during the inflammation is followed by activation and secretion of pro-inflammatory molecules such as calprotectin. Calprotectin is stable in stool up to 7 days and can therefore be used as a non-invasive marker for diagnosis, treatment and measurement of the disease activity in patients with IBD. The most common method for analysis of calprotectin concentration is ELISA. This method is time-consuming and many manufactures have therefore developed rapid tests as a faster alternative for quantification of calprotectin in stool.

    Aim The aim of the study was to evaluate one ELISA and one rapid test from the same manufacture compare the data with the existing ELISA-method used in the laboratory for routine analysis.

    Methods A rapid test (CalFast) and an ELISA method (CalPrest) from Eurospital, were used for analysis of calprotectin in stool. These two methods were compared with known concentrations of calprotectin obtained by the ELISA method from Bühlmann used in the routine work. 

    Results The results showed poor correlation between the rapid test and the ELISA method. Furthermore, the comparison between the two ELISA-methods showed a poor correlation.

    Conclusion Evaluation of the two new methods showed poor correlation with the existing ELISA method from Bühlmann. Evaluation of the rapid test did not show any correlation with the two ELISA methods and the data cannot be trusted. It is difficult to conclude which of the two ELISA methods gives accurate results due to the absence of an international standard.

  • 29.
    Alfredsson-Timmins, Jenny
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Kristell, Carolina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Henningson, Frida
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Lyckman, Sara
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Bjerling, Pernilla
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Reorganization of chromatin is an early response to nitrogen starvation in Schizosaccharomyces pombe2009In: Chromosoma, ISSN 0009-5915, E-ISSN 1432-0886, Vol. 118, no 1, p. 99-112Article in journal (Refereed)
    Abstract [en]

    There are several documented events of changes in subnuclear localization during gene activation. However, there are conflicting data on whether the nuclear periphery is a compartment for gene repression or activation, and whether genes are moved to the pores at the nuclear membrane (NM) or not during gene activation. Nitrogen starvation of fission yeast serves as a good model system for studying gene induction since it causes fast regulation of hundreds of genes. In this study the subnuclear localization of two gene clusters repressed by nitrogen was investigated. During normal growth conditions the gene clusters localized to the nuclear periphery at the opposite side of the nucleus as compared to the spindle pole body (SPB). This constrained localization was dependent on the histone deacetylase Clr3, known to transcriptionally repress genes in these clusters. Already 20 minutes after nitrogen depletion drastic changes in subnuclear localization of the two loci were observed, away from the NM towards the nuclear interior. At least for one of the clusters the movement was clearly transcription dependent. Data presented here illustrates how interconnected events of gene activation and nuclear reorganization are, as well as provides a suggestion of how nuclear organization might be maintained.

  • 30.
    Ali, Iman
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Pan Genera Detection-​test, a new bacterial detection systems for durability extension of platelets2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Platelets are blood cells that important for transfusion and blood coagulation. Patients will get transfusion with manufactured platelets if they have platelet disorder or extensive blood loss. Platelets isolated from 5 buffy-coats by different ways at a blood center are usable for about 5 days. The sustainability of platelets could be extended by various methods. The previously used method in Gävle BLC was the bacterial culture method using aerobic and anaerobic bottles, which took 5 days to receive an answer. Therefore, this project used Pan Genera Detection (PGD) test as an alternative method to extend the sustainability of platelets. The PGD ​​Test is a rapid method that only takes about 30 minutes. This study showed that PGD the test yielded good results to reduced costs compared with the old method. The durability was extended by 36 h and the analysis runs in routine now at Gävle blood center.

    Finally, this project has shown that PGD-test is a cheaper, faster and safer approach for patient health compared to the old method, the bacterial culture method.

  • 31. Allabwani, Haifaa
    Verification of Bordetella pertussis and Bordetella holmesii withreal-time PCR2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bordetella pertussis causes whooping cough, which is a very dangerous disease especially for children. A correct diagnose is very important. Bordetella pertussis usually misidentifies with Bordetella holmesii by routine polymerase chain reaction.The aim of the study is to evaluate a target sequence that can verify a Bordetella pertussis infection and distinguish it from other Bordetella species, in specific Bordetella holmesii.The target sequences' sensitivities were tested on the control bacterial strains. Sixty-five clinical samples were analyzed with real-time PCR.The study concludes that both IS481 and ptxA target sequences are highly specific to detect B. pertussis, while both ho_IS1001 and IS481 are specific to detect B. holmesii. Pa_IS1001 is specific to detect B. parapertussis. Culturing is less sensitive to detect Bordetella infection than real-time PCR.

  • 32.
    Allardyce, Benjamin J.
    et al.
    Deakin Univ, Inst Frontier Mat, Geelong, Vic, Australia..
    Rajkhowa, Rangam
    Deakin Univ, Inst Frontier Mat, Geelong, Vic, Australia..
    Dilley, Rodney J.
    Univ Western Australia, Sch Surg, Ear Sci Inst Australia, Nedlands, WA 6009, Australia.;Univ Western Australia, Sch Surg, Ear Sci Ctr, Nedlands, WA 6009, Australia..
    Xie, Zhigang
    Deakin Univ, Inst Frontier Mat, Geelong, Vic, Australia..
    Campbell, Luke
    Univ Melbourne, Dept Otolaryngol, Melbourne, Vic 3010, Australia..
    Keating, Adrian
    Univ Western Australia, Sch Mech & Chem Engn, Nedlands, WA 6009, Australia..
    Atlas, Marcus D.
    Univ Western Australia, Sch Surg, Ear Sci Inst Australia, Nedlands, WA 6009, Australia.;Univ Western Australia, Sch Surg, Ear Sci Ctr, Nedlands, WA 6009, Australia..
    von Unge, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centre for Clinical Research, County of Västmanland. Akershus Univ Hosp, Dept ENT, Oslo, Norway.;Univ Oslo, Oslo, Norway..
    Wang, Xungai
    Deakin Univ, Inst Frontier Mat, Geelong, Vic, Australia..
    Comparative acoustic performance and mechanical properties of silk membranes for the repair of chronic tympanic membrane perforations2016In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 64, p. 65-74Article in journal (Refereed)
    Abstract [en]

    The acoustic and mechanical properties of silk membranes of different thicknesses were tested to determine their suitability as a repair material for tympanic membrane perforations. Membranes of different thickness (10-100 mu m) were tested to determine their frequency response and their resistance to pressure loads in a simulated ear canal model. Their mechanical rigidity to pressure loads was confirmed by tensile testing. These membranes were tested alongside animal cartilage, currently the strongest available myringoplasty graft as well as paper, which is commonly used for simpler procedures. Silk membranes showed resonant frequencies within the human hearing range and a higher vibrational amplitude than cartilage, suggesting that silk may offer good acoustic energy transfer characteristics. Silk membranes were also highly resistant to simulated pressure changes in the middle ear, suggesting they can resist retraction, a common cause of graft failure resulting from chronic negative pressures in the middle ear. Part of this strength can be explained by the substantially higher modulus of silk films compared with cartilage. This allows for the production of films that are much thinner than cartilage, with superior acoustic properties, but that still provide the same level of mechanical support as thicker cartilage. Together, these in vitro results suggest that silk membranes may provide good hearing outcomes while offering similar levels of mechanical support to the reconstructed middle ear.

  • 33. Almeflo, Sandra
    The effect of shifting host plants on growth of butterfly larvae of Polygonia c-album.2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 34. Alsaadi, Hani
    A new High Sensitive Functional Nephelometrical Assay for Assaying C- reactive protein in Serum Based on Phosphocholine Interaction2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    C-reactive protein (CRP) is able to bind phosphocholine in the presence of calcium ions. According to a previous functional property of CRP, we tried to develop an affordable and cheap high sensitive nephelometric CRP assay using soy oil.

    Serum samples were measured by Nephelometer BNII (Siemens), by mixing the serum with diluted soy oil emulsion (Intralipid

    ®

    20%) and Tris-calcium buffer (PH 7.5). The measurement took place after 12 min incubation time at 37°C by measuring the agglutination between CRP and phosphocholine. Results from our automated functional assay were compared with results obtained using an immunoturbidimetric CRP assay.

    Results showed a good correlation coefficient for method comparison between functional nephelometric CRP assay and immunoturbidimetric CRP assay, r = 0.895, significance level p <0.0001. The limit of detection for the functional nephelometric CRP assay was 0.1 mg/L. However, the within run % CV values for the functional assay were 6.1 % (20 mg/L), 4.7 % (50 mg/L) and 4.5 % (100 mg/L). The between-run % CV values were 17.6 % (20 mg/L), 18.8 % (50 mg/L), and 11.3 % (100 mg/L).

    The new functional nephelometric CRP assay enables high sensitive CRP measurement in serum in the range of 0.1 mg/L to 300 mg/L. The functional assay could be used for veterinary analysis due to the ability to measure CRP according to the functional properties, not the morphological properties which depend on specific antibodies.

  • 35.
    Alsén, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Immunohistochemical evaluation of antibodies for staining of mouse spinal cord and mouse neuronal cells2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 36.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Dunås, Finn
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences.
    Löfblom, John
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Ståhl, Stefan
    Selection of an optimal cysteine-containing peptide-based chelator for labeling of affibody molecules with 188Re2014In: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 87, p. 519-528Article in journal (Refereed)
    Abstract [en]

    Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1 ± 0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172 ± 32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.

  • 37.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Westerlund, Kristina
    KTH Royal Inst Technol, Div Prot Technol, Sch Biotechnol, Stockholm, Sweden..
    Velletta, Justin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Eriksson Karlström, Amelie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Evaluation of affibody molecule-based PNA-mediated radionuclide pretargeting: Development of an optimized conjugation protocol and 177Lu labeling2017In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 54, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Introduction: We have previously developed a pretargeting approach for affibody-mediated cancer therapy based on PNA-PNA hybridization. In this article we have further developed this approach by optimizing the production of the primary agent, Z(HER2.342)-SR-HP1, and labeling the secondary agent, HP2, with the therapeutic radionuclide Lu-177. We also studied the biodistribution profile of Lu-177-HP2 in mice, and evaluated pretargeting with Lu-177-HP2 in vitro and in vivo.

    Methods: The biodistribution profile of Lu-177-HP2 was evaluated in NMRI mice and compared to the previously studied In-111-HP2. Pretargeting using Lu-177-HP2 was studied in vitro using the HER2-expressing cell lines BT-474 and SKOV-3, and in vivo in mice bearing SKOV-3 xenografts.

    Results and conclusion: Using an optimized production protocol for Z(HER2:342)-SR-HP1 the ligation time was reduced from 15 h to 30 min, and the yield increased from 45% to 70%. Lu-177-labeled HP2 binds specifically in vitro to BT474 and SKOV-3 cells pre-treated with Z(HER2:342)-SR-HP1.Lu-177-HP2 was shown to have a more rapid blood clearance compared to In-111-HP2 in NMRI mice, and the measured radioactivity in blood was 0.22 +/- 0.1 and 0.68 +/- 0.07%ID/g for Lu-177- and In-111-HP2, respectively, at 1 h p.i. In contrast, no significant difference in kidney uptake was observed (4.47 +/- 1.17 and 3.94 +/- 0.58%ID/g for Lu-177- and In-111-HP2, respectively, at I h p.i.). Co-injection with either Gelofusine or lysine significantly reduced the kidney uptake for Lu-177-HP2 (1.0 +/- 0.1 and 1.6 +/- 0.2, respectively, vs. 2.97 +/- 0.87%ID/g in controls at 4 h p.i.). Lu-177-HP2 accumulated in SKOV-3 xenografts in BALB/C nu/nu mice when administered after injection of Z(HER2:342)-SR-HP1. Without pre-injection of Z(HER2:342)-SR-HP1, the uptake of Lu-177-HP2 was about 90-fold lower in tumor (0.23 +/- 0.08 vs. 20.7 +/- 3.5%ID/g). The tumor-to-kidney radioactivity accumulation ratio was almost 5-fold higher in the group of mice pre-injected with Z(HER2:342)-SR-HP1. In conclusion, (177)LuHP2 was shown to be a promising secondary agent for affibody-mediated tumor pretargeting in vivo.

  • 38.
    Alvarsson, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Eklund, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Andersson, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Carlsson, Lars
    AstraZeneca R&D.
    Spjuth, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Wikberg, Jarl E. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Benchmarking Study of Parameter Variation When Using Signature Fingerprints Together with Support Vector Machines2014In: Journal of Chemical Information and Modeling, ISSN 1549-9596, Vol. 54, no 11, p. 3211-3217Article in journal (Refereed)
    Abstract [en]

    QSAR modeling using molecular signatures and support vector machines with a radial basis function is increasingly used for virtual screening in the drug discovery field. This method has three free parameters: C, ?, and signature height. C is a penalty parameter that limits overfitting, ? controls the width of the radial basis function kernel, and the signature height determines how much of the molecule is described by each atom signature. Determination of optimal values for these parameters is time-consuming. Good default values could therefore save considerable computational cost. The goal of this project was to investigate whether such default values could be found by using seven public QSAR data sets spanning a wide range of end points and using both a bit version and a count version of the molecular signatures. On the basis of the experiments performed, we recommend a parameter set of heights 0 to 2 for the count version of the signature fingerprints and heights 0 to 3 for the bit version. These are in combination with a support vector machine using C in the range of 1 to 100 and gamma in the range of 0.001 to 0.1. When data sets are small or longer run times are not a problem, then there is reason to consider the addition of height 3 to the count fingerprint and a wider grid search. However, marked improvements should not be expected.

  • 39.
    Andersson, Dan I
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Shrinking Bacterial Genomes: Former skeptics recognize that the genomes of microbial parasites and symbionts are subject to dynamic downsizing2008In: Microbe, ISSN 1558-7452, Vol. 3, no 3, p. 124-130Article in journal (Refereed)
  • 40.
    Andersson, Dan I.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Hughes, Diarmaid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Gene amplification and adaptive evolution in bacteria2009In: Annual Review of Genetics, ISSN 0066-4197, E-ISSN 1545-2948, Vol. 43, p. 167-195Article, review/survey (Refereed)
    Abstract [en]

    Gene duplication-amplification (GDA) processes are highly relevant biologically because they generate extensive and reversible genetic variation on which adaptive evolution can act. Whenever cellular growth is restricted, escape from these growth restrictions often occurs by GDA events that resolve the selective problem. In addition, GDA may facilitate subsequent genetic change by allowing a population to grow and increase in number, thereby increasing the probability for subsequent adaptive mutations to occur in the amplified genes or in unrelated genes. Mathematical modeling of the effect of GDA on the rate of adaptive evolution shows that GDA will facilitate adaptation, especially when the supply of mutations in the population is rate-limiting. GDA can form via several mechanisms, both RecA-dependent and RecA-independent, including rolling-circle amplification and nonequal crossing over between sister chromatids. Due to the high intrinsic instability and fitness costs associated with GDAs, they are generally transient in nature, and consequently their evolutionary and medical importance is often underestimated.

  • 41.
    Andersson, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Evaluation of Correlation between mRNA and Protein Expression of Tripeptidyl-Peptidase II: Possible Future Use as a Biomarker for Cancer?2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cancer remains one of the most common causes for death in the world today. Researchers are continuously trying to improve old, and develop new, methods in order to strife this global problem. Much research is being made trying to find new specific biomarkers that can be used to detect and diagnose cancer in an early stage.

    One candidate protein for possible future use as a biomarker is tripeptidyl-peptidase II (TPPII) which has previously been shown to be up-regulated in Burkitt´s lymphoma. This paper focuses on the expression of TPPII on an mRNA-level to see if there is any difference between expression in human leucocytes from patients with a leukemia diagnosis and a healthy volunteer, in order to evaluate if the expression of TPPII have any future use as a biomarker.

    Patient samples were analyzed using real time qPCR, to study the expression of mRNA, and Western blot, in order to correlate the mRNA findings with protein expression. Three different cell lines with different characteristics regarding expression and function of TPPII were also used to validate the methods used and for comparison with the patient samples analyzed.

    A difference in expression of mRNA were seen between the different patient samples, both individually and between larger groups of samples with the same diagnosis, indicating a large individual variation, thus making future use in a clinical setting difficult. However, seeing as only a few samples were analyzed in this study, more research must be done in order to draw any final conclusions.

  • 42.
    Andersson, Frida
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Dementia; common cause of suicide among elderly?2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Elderly committing suicide can be in a “preclinical phase” of dementia. Depressive symptoms may indicate a risk to develop a disease of dementia, for example Alzheimer’s Disease. Today almost 10% of the Swedish population older than 65 years suffer from a cognitive impairment diagnosed as dementia. Symptoms of dementia are associated with degenerative changes in the brain caused by a deposition of amyloid, leading among others things to a nerve cell death. A clinical diagnosis can be hard to set, and a definitive diagnose can only be set after a pathological examination, which only is possible after death. For this study we used Congo red staining of brains sections to find amyloid in autopsies from elderly people committing suicide. 35 cases (>60 year) were studied. Of the 35 cases 1/3 showed to be positive for amyloid deposition. This result in addition to other studies suggest that depressive symptoms is a “preclinical phase” of dementia, and therefore the suicide risk for this group must be consider to be elevated. However, more reliable prospective studies most be done to confirm this retrospective study.

  • 43.
    Andersson, Jim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    LEFT VENTRICULAR EJECTION FRACTION: A RETROSPECTIVE STUDY COMPARING 2D ECHOCARDIOGRAPHY AND GATED SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT) IN CLINICAL USE.2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Objectives

    The aim of this study was to compare left ventricular ejection fraction (LVEF) results derived from gated single photon emission computed tomography (SPECT) using Cedars-Sinai quantitative gated SPECT (QGS) processing software with results from 2D echocardiography, both obtained in routine clinical diagnostic use.

     

    Methods

    Data from previously performed tests were obtained from 73 patients who had undergone both 2D echocardiography and gated SPECT within a time span of 6 months and had not had significant events that could influence LVEF. LVEF from 2D echocardiography was reassessed to obtain discrete values and then the data was compared using Bland-Altman analysis.

     

    Results

    The correlation between the tests was shown to be good, but precision lacked. Bland-Altman analysis showed a bias of -0.8 percentage points when gated SPECT compared to mean values and 2 standard deviations (SD) ranged from -20.2 to 18.6.

     

    Conclusions

    LVEF values from the two methods can differ quite a bit and comparisons between them should be done with great caution.

  • 44.
    Andersson, Karl
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Characterization of Biomolecular Interactions Using a Multivariate Approach2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents a novel bioinformatic methodology denoted the bio-chemometric approach. The methodology is designed for generation of detailed descriptions and predictions of biomolecular interactions. It is based on multivariate analysis of the sensitivity of a biomolecular interaction to multiple minor changes in the experimental conditions. In this work, either the chemical environment where the interaction takes place, or the molecular structure of one of the interacting molecules, was varied. The sensitivity of the interaction to the performed variations was presented as a vector called the sensitivity fingerprint. The bio-chemometric approach was tested on several biomolecular interactions. Useful descriptions of the interactions were obtained by measuring binding kinetics for each interaction in 12-20 different buffers and correlating buffer composition to binding kinetics. The obtained chemical sensitivity fingerprints were reproducible, significantly different and showed a weak correlation to binding site properties for the tested interactions. The results indicate that the fingerprints contained useful information about the binding site. The predictive ability of the bio-chemometric approach was tested on two different biomolecular interactions where one of the binding partners was slightly modified into multiple analogues by amino acid exchanges. In one example, interactions of 18 peptide analogues with an antibody gave data that could be used for accurate prediction of the dissociation rates of novel analogues. Reliable predictions of binding kinetics and affinity were also obtained for single domain camel antibody analogues binding to a protein antigen. By using the three-dimensional structure of camel antibodies and data obtained using the bio-chemometric approach, even the importance of non-exchanged amino acids for the binding could be estimated. The bio-chemometric approach can potentially improve the development of peptides and proteins for therapeutic and diagnostic use. It is suggested to be valid for general use in biochemistry.

    List of papers
    1. Identification and Optimization of Regeneration Conditions for Affinity-Based Biosensor Assays. A Multivariate Cocktail Approach
    Open this publication in new window or tab >>Identification and Optimization of Regeneration Conditions for Affinity-Based Biosensor Assays. A Multivariate Cocktail Approach
    1999 In: Analytical Chemistry, Vol. 71, p. 2475-2481Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-91945 (URN)
    Available from: 2004-06-02 Created: 2004-06-02Bibliographically approved
    2. Kinetic Characterization of the Interaction of the Z-fragment of Protein A With Mouse-IgG3 in a Volume in Chemical Space
    Open this publication in new window or tab >>Kinetic Characterization of the Interaction of the Z-fragment of Protein A With Mouse-IgG3 in a Volume in Chemical Space
    Show others...
    1999 In: Proteins: Structure, Function, and Genetics, Vol. 37, p. 494-498Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-91946 (URN)
    Available from: 2004-06-02 Created: 2004-06-02Bibliographically approved
    3. Predicting the kinetics of peptide-antibody interactions using a multivariate experimental design of sequence and chemical space
    Open this publication in new window or tab >>Predicting the kinetics of peptide-antibody interactions using a multivariate experimental design of sequence and chemical space
    Show others...
    2001 (English)In: Journal of Molecular Recognition, Vol. 14, p. 62-71Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-91947 (URN)
    Available from: 2004-06-02 Created: 2004-06-02 Last updated: 2010-09-14Bibliographically approved
    4. Kinetic and affinity predictions of a protein-protein interaction using multivariate experimental design
    Open this publication in new window or tab >>Kinetic and affinity predictions of a protein-protein interaction using multivariate experimental design
    Show others...
    2002 In: Journal of Biological Chemistry, Vol. 277, no 33, p. 29897-29907Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-91948 (URN)
    Available from: 2004-06-02 Created: 2004-06-02Bibliographically approved
    5. Structural Modeling Extends QSAR Analysis of Antibody-Lysozyme Interactions to 3D-QSAR
    Open this publication in new window or tab >>Structural Modeling Extends QSAR Analysis of Antibody-Lysozyme Interactions to 3D-QSAR
    2003 In: Biophysical Journal, Vol. 84, p. 2264-2272Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-91949 (URN)
    Available from: 2004-06-02 Created: 2004-06-02Bibliographically approved
  • 45.
    Andersson, Marlene
    et al.
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden..
    Jia, Qiupin
    Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, P.R. China..
    Abella, Ana
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Lee, Xiau-Yeen
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Landreh, Michael
    Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK..
    Purhonen, Pasi
    Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.; School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden..
    Hebert, Hans
    Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.; School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden..
    Tenje, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Uppsala University, Science for Life Laboratory, SciLifeLab. Department of Biomedical Engineering, Lund University, Lund, Sweden..
    Robinson, Carol V.
    Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK..
    Meng, Qing
    Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, P.R. China..
    Plaza, Gustavo R.
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Johansson, Jan
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.; Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden.; Karolinska Institutet.
    Rising, Anna
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.;Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden.; Karolinska Institutet.
    Biomimetic spinning of artificial spider silk from a chimeric minispidroin2017In: Nature Chemical Biology, ISSN 1552-4450, E-ISSN 1552-4469, Vol. 13, no 3, p. 262-264Article in journal (Refereed)
    Abstract [en]

    Herein we present a chimeric recombinant spider silk protein (spidroin) whose aqueous solubility equals that of native spider silk dope and a spinning device that is based solely on aqueous buffers, shear forces and lowered pH. The process recapitulates the complex molecular mechanisms that dictate native spider silk spinning and is highly efficient; spidroin from one liter of bacterial shake-flask culture is enough to spin a kilometer of the hitherto toughest as-spun artificial spider silk fiber.

  • 46. Andersson, Sara
    Effects of the different surface nanotopography of Poly(MAA-DAP) on the activation of the cascade systems in blood2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Biomaterials are used for transplants and dialyses. A biomaterial that is not well adjusted to the body but is inserted into the body, may cause serious thrombosis and thromboembolic events as well as inflammation. PVC hoses used in dialysis today causes substantial complement activation. Therefore, poly (MAA-DAP), a polymer that has been developed in to four different nanotopographies, could be a possible biomaterial used in haemodialysis and catheters.Aim: The aim of these nanostructures is to see if it can be used as a substitute for PVC, and to see if there is a difference between the four different structures. Thus, these nanotopographies should have a low thrombogenic effect and a low complement activation.Material and methods: To analyse the compatibility with the cascade system, the intrinsic pathway and the alternative pathway, blood samples were analysed by use of ELISA. Plasma was collected from the 2-well slide chamber blood experiments were the whole blood was added to a slide chamber. The amount of platelets was, in addition to ELISA, also analysed using Sysmex XP-300 cellcounter.Results: The results showed that the MAA-DAP polymer surfaces were complement activating but not platelet activating. There was no significant difference in complement activation between the different MAA-DAP polymer surfaces. The more structured wires and fibrils were slightly more platelet activating but the difference was not significant enough.Conclusion: It can be concluded that the nanotopographies do not have significant impact on blood, it is the polymer material that effects the blood. Future studies could be performed on other type of material with different topographies and with blood.

  • 47.
    Andersson, Vidar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Evaluation of CellaVision DM1200 Vet and its ability to differentiate feline leukocytes compared to manual differential count and Advia 21202016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Leukocyte differential count in peripheral blood smear has, ever since the method was developed more than 100 years ago, been one of the most frequently used diagnostics tool in the routine hematology laboratory. The manual differential count of leukocytes using a microscope is still the standard method in most small and medium sized laboratories. Even though the method does not require any expensive instruments it comes at a high cost due to it being labor intensive and time consuming. In recent years the rapid technical advancements has led to the development of automatic or semi-automatic methods in which the leukocytes are differentiated. In this study a method comparison was made between manual leukocyte differential counts, CellaVision DM1200 Vet and Advia 2120 when analyzing 106 fresh, feline blood samples. The general agreement between results was good, especially for the most common leukocytes, such as neutrophils and lymphocytes. Results for eosinophils and monocytes had moderate agreement. The confidence intervals were generally wider when CellaVision DM1200 Vet was compared with Advia 2120, than when CellaVision DM1200 Vet was compared to the manual differential count. Despite the fact that Advia 2120 and CellaVision DM1200 Vet are both faster and often show comparable results to the manual differential count, the light microscopy will remain the gold standard for difficult samples, where there is suspicion of inflammation (band neutrophils), intracellular microorganisms, reactive lymphocytes or if the sample contains a high degree of smudge cells or artifacts. 

  • 48.
    Andrae, Johanna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    Gouveia, Leonor
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    Gallini, Radiosa
    Karolinska Inst, Dept Med Biochem & Biophys, S-17177 Stockholm, Sweden..
    He, Liqun
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    Fredriksson, Linda
    Karolinska Inst, Dept Med Biochem & Biophys, S-17177 Stockholm, Sweden..
    Nilsson, Ingrid
    Karolinska Inst, Dept Med Biochem & Biophys, S-17177 Stockholm, Sweden..
    Johansson, Bengt R.
    Univ Gothenburg, Sahlgrenska Acad, Inst Biomed, Electron Microscopy Unit, S-40530 Gothenburg, Sweden..
    Eriksson, Ulf
    Karolinska Inst, Dept Med Biochem & Biophys, S-17177 Stockholm, Sweden..
    Betsholtz, Christer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    A role for PDGF-C/PDGFR alpha signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex2016In: BIOLOGY OPEN, ISSN 2046-6390, Vol. 5, no 4, p. 461-474Article in journal (Refereed)
    Abstract [en]

    Platelet-derived growth factor-C (PDGF-C) is one of three known ligands for the tyrosine kinase receptor PDGFR alpha. Analysis of Pdgfc null mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFR alpha ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants for Pdgfc(-/-) and Pdgfra(GFP/+). These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS), where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data on Pdgfa, Pdgfc and Pdgfra in the cerebral cortex and microarray data on cerebral meninges.

  • 49. Andreassen, Jenny
    PRESERVATION OF DNA AND BACTERIA FOR INCORPORATION IN CULTURE COLLECTIONS2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study contains of two different parts, an investigation of long time stored prokaryotic DNA for incorporation in a DNA-bank, and lyophilization of two Flavobacterium strains with different lyoprotectants and validation of an alternative method for determination of concentration. For the DNA-project PCR and capillary gel electrophoresis was used for sequencing, and lyophilization, CFU-counts and Start of growth time was used to investigate the Flavobacteriums. 87.5% of the DNA samples with maintained quality were correctly identified. The lyophilization was successful, with varying results from the revivals. The validation could not be completed due to incoherent results between the two methods.An alternative validation method is suggested. The presence of viable but non-cultivable should also be considerated for continued studies.

  • 50.
    Ansell, Brendan R. E.
    et al.
    Univ Melbourne, Fac Vet & Agr Sci, Parkville, Vic 3010, Australia..
    McConville, Malcolm J.
    Univ Melbourne, Inst Bio21, Parkville, Vic 3010, Australia..
    Ma'ayeh, Showgy Y.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Dagley, Michael J.
    Univ Melbourne, Inst Bio21, Parkville, Vic 3010, Australia..
    Gasser, Robin B.
    Univ Melbourne, Fac Vet & Agr Sci, Parkville, Vic 3010, Australia..
    Svärd, Staffan G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Jex, Aaron R.
    Univ Melbourne, Fac Vet & Agr Sci, Parkville, Vic 3010, Australia..
    Drug resistance in Giardia duodenalis2015In: Biotechnology Advances, ISSN 0734-9750, E-ISSN 1873-1899, Vol. 33, no 6, p. 888-901Article, review/survey (Refereed)
    Abstract [en]

    Giardia duodenalis is a microaerophilic parasite of the human gastrointestinal tract and a major contributor to diarrheal and post-infectious chronic gastrointestinal disease world-wide. Treatment of G. duodenalis infection currently relies on a small number of drug classes. Nitroheterocyclics, in particular metronidazole, have represented the front line treatment for the last 40 years. Nitroheterocyclic-resistant G. duodenalis have been isolated from patients and created in vitro, prompting considerable research into the biomolecular mechanisms of resistance. These compounds are redox-active and are believed to damage proteins and DNA after being activated by oxidoreductase enzymes in metabolically active cells. In this review, we explore the molecular phenotypes of nitroheterocyclic-resistant G. duodenalis described to date in the context of the protisfs unusual glycolytic and antioxidant systems. We propose that resistance mechanisms are likely to extend well beyond currently described resistance-associated enzymes (i.e., pyruvate ferredoxin oxidoreductases and nitroreductases), to include NAD(P)H- and flavin-generating pathways, and possibly redox-sensitive epigenetic regulation. Mechanisms that allow G. duodenalis to tolerate oxidative stress may lead to resistance against both oxygen and nitroheterocyclics, with implications for clinical control. The present review highlights the potential for systems biology tools and advanced bioinformatics to further investigate the multifaceted mechanisms of nitroheterocyclic resistance in this important pathogen.

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